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32+ messages / 7 participants
[nested] [flat]
* [PATCH v2 1/1] Add hint message for check_log_destination
@ 2023-07-07 07:48 Japin Li <[email protected]>
0 siblings, 0 replies; 32+ messages in thread
From: Japin Li @ 2023-07-07 07:48 UTC (permalink / raw)
---
src/backend/utils/error/elog.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 5898100acb..a32f9613be 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -2228,8 +2228,22 @@ check_log_destination(char **newval, void **extra, GucSource source)
#endif
else
{
+ StringInfoData errhint;
+
+ initStringInfo(&errhint);
+ appendStringInfo(&errhint, "\"stderr\"");
+#ifdef HAVE_SYSLOG
+ appendStringInfo(&errhint, ", \"syslog\"");
+#endif
+#ifdef WIN32
+ appendStringInfo(&errhint, ", \"eventlog\"");
+#endif
+ appendStringInfo(&errhint, ", \"csvlog\", and \"jsonlog\"");
+
GUC_check_errdetail("Unrecognized key word: \"%s\".", tok);
+ GUC_check_errhint("Valid values are combinations of %s.", errhint.data);
pfree(rawstring);
+ pfree(errhint.data);
list_free(elemlist);
return false;
}
--
2.25.1
--=-=-=--
^ permalink raw reply [nested|flat] 32+ messages in thread
* [PATCH v3 1/1] Add hint message for check_log_destination
@ 2023-07-07 07:48 Japin Li <[email protected]>
0 siblings, 0 replies; 32+ messages in thread
From: Japin Li @ 2023-07-07 07:48 UTC (permalink / raw)
---
src/backend/utils/error/elog.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 5898100acb..a7545dcbd9 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -2228,8 +2228,22 @@ check_log_destination(char **newval, void **extra, GucSource source)
#endif
else
{
+ StringInfoData errhint;
+
+ initStringInfo(&errhint);
+ appendStringInfoString(&errhint, "\"stderr\"");
+#ifdef HAVE_SYSLOG
+ appendStringInfoString(&errhint, ", \"syslog\"");
+#endif
+#ifdef WIN32
+ appendStringInfoString(&errhint, ", \"eventlog\"");
+#endif
+ appendStringInfoString(&errhint, ", \"csvlog\", and \"jsonlog\"");
+
GUC_check_errdetail("Unrecognized key word: \"%s\".", tok);
+ GUC_check_errhint("Valid values are combinations of %s.", errhint.data);
pfree(rawstring);
+ pfree(errhint.data);
list_free(elemlist);
return false;
}
--
2.25.1
--=-=-=
Content-Type: text/plain
--
Regrads,
Japin Li.
--=-=-=--
^ permalink raw reply [nested|flat] 32+ messages in thread
* [PATCH v2 1/1] Add hint message for check_log_destination
@ 2023-07-07 07:48 Japin Li <[email protected]>
0 siblings, 0 replies; 32+ messages in thread
From: Japin Li @ 2023-07-07 07:48 UTC (permalink / raw)
---
src/backend/utils/error/elog.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 5898100acb..a32f9613be 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -2228,8 +2228,22 @@ check_log_destination(char **newval, void **extra, GucSource source)
#endif
else
{
+ StringInfoData errhint;
+
+ initStringInfo(&errhint);
+ appendStringInfo(&errhint, "\"stderr\"");
+#ifdef HAVE_SYSLOG
+ appendStringInfo(&errhint, ", \"syslog\"");
+#endif
+#ifdef WIN32
+ appendStringInfo(&errhint, ", \"eventlog\"");
+#endif
+ appendStringInfo(&errhint, ", \"csvlog\", and \"jsonlog\"");
+
GUC_check_errdetail("Unrecognized key word: \"%s\".", tok);
+ GUC_check_errhint("Valid values are combinations of %s.", errhint.data);
pfree(rawstring);
+ pfree(errhint.data);
list_free(elemlist);
return false;
}
--
2.25.1
--=-=-=--
^ permalink raw reply [nested|flat] 32+ messages in thread
* [PATCH v3 1/1] Add hint message for check_log_destination
@ 2023-07-07 07:48 Japin Li <[email protected]>
0 siblings, 0 replies; 32+ messages in thread
From: Japin Li @ 2023-07-07 07:48 UTC (permalink / raw)
---
src/backend/utils/error/elog.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 5898100acb..a7545dcbd9 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -2228,8 +2228,22 @@ check_log_destination(char **newval, void **extra, GucSource source)
#endif
else
{
+ StringInfoData errhint;
+
+ initStringInfo(&errhint);
+ appendStringInfoString(&errhint, "\"stderr\"");
+#ifdef HAVE_SYSLOG
+ appendStringInfoString(&errhint, ", \"syslog\"");
+#endif
+#ifdef WIN32
+ appendStringInfoString(&errhint, ", \"eventlog\"");
+#endif
+ appendStringInfoString(&errhint, ", \"csvlog\", and \"jsonlog\"");
+
GUC_check_errdetail("Unrecognized key word: \"%s\".", tok);
+ GUC_check_errhint("Valid values are combinations of %s.", errhint.data);
pfree(rawstring);
+ pfree(errhint.data);
list_free(elemlist);
return false;
}
--
2.25.1
--=-=-=
Content-Type: text/plain
--
Regrads,
Japin Li.
--=-=-=--
^ permalink raw reply [nested|flat] 32+ messages in thread
* [PATCH v4 1/1] Add hint message for check_log_destination
@ 2023-07-14 01:26 Japin Li <[email protected]>
0 siblings, 0 replies; 32+ messages in thread
From: Japin Li @ 2023-07-14 01:26 UTC (permalink / raw)
---
src/backend/utils/error/elog.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 5898100acb..dccbabf40a 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -2228,8 +2228,22 @@ check_log_destination(char **newval, void **extra, GucSource source)
#endif
else
{
+ StringInfoData errhint;
+
+ initStringInfo(&errhint);
+ appendStringInfoString(&errhint, "stderr");
+#ifdef HAVE_SYSLOG
+ appendStringInfoString(&errhint, ", syslog");
+#endif
+#ifdef WIN32
+ appendStringInfoString(&errhint, ", eventlog");
+#endif
+ appendStringInfoString(&errhint, ", csvlog, and jsonlog");
+
GUC_check_errdetail("Unrecognized key word: \"%s\".", tok);
+ GUC_check_errhint("Valid values are combinations of %s.", errhint.data);
pfree(rawstring);
+ pfree(errhint.data);
list_free(elemlist);
return false;
}
--
2.41.0
--=-=-=--
^ permalink raw reply [nested|flat] 32+ messages in thread
* [PATCH v4 1/1] Add hint message for check_log_destination
@ 2023-07-14 01:26 Japin Li <[email protected]>
0 siblings, 0 replies; 32+ messages in thread
From: Japin Li @ 2023-07-14 01:26 UTC (permalink / raw)
---
src/backend/utils/error/elog.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 5898100acb..dccbabf40a 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -2228,8 +2228,22 @@ check_log_destination(char **newval, void **extra, GucSource source)
#endif
else
{
+ StringInfoData errhint;
+
+ initStringInfo(&errhint);
+ appendStringInfoString(&errhint, "stderr");
+#ifdef HAVE_SYSLOG
+ appendStringInfoString(&errhint, ", syslog");
+#endif
+#ifdef WIN32
+ appendStringInfoString(&errhint, ", eventlog");
+#endif
+ appendStringInfoString(&errhint, ", csvlog, and jsonlog");
+
GUC_check_errdetail("Unrecognized key word: \"%s\".", tok);
+ GUC_check_errhint("Valid values are combinations of %s.", errhint.data);
pfree(rawstring);
+ pfree(errhint.data);
list_free(elemlist);
return false;
}
--
2.41.0
--=-=-=--
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
@ 2025-02-12 04:43 Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Pavel Stehule @ 2025-02-12 04:43 UTC (permalink / raw)
To: jian he <[email protected]>; +Cc: Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
Hi
rebase after a654af21ae522cc8e867e052defd16f76ffaef2e
Regards
Pavel
Attachments:
[text/x-patch] v20250212-0020-this-patch-changes-error-message-column-doesn-t-exis.patch (29.9K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/3-v20250212-0020-this-patch-changes-error-message-column-doesn-t-exis.patch)
download | inline diff:
From 5eeb8df7bd4d7f221e99945f432406203f9788ed Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:10:39 +0100
Subject: [PATCH 20/22] this patch changes error message "column doesn't exist"
to message "column or variable doesn't exist"
The error message will be more correct. Today, missing PL/pgSQL variable can be reported. The change has
impact on lot of regress tests not directly related to session variables, and then it is distributed as separate patch
---
src/backend/parser/parse_expr.c | 5 ++-
src/backend/parser/parse_relation.c | 25 ++++++++++++---
src/backend/parser/parse_target.c | 8 +++--
src/include/parser/parse_expr.h | 4 +++
src/pl/plpgsql/src/expected/plpgsql_array.out | 2 +-
.../plpgsql/src/expected/plpgsql_record.out | 4 +--
.../src/expected/plpgsql_session_variable.out | 2 +-
src/pl/tcl/expected/pltcl_queries.out | 12 +++----
.../isolation/expected/session-variable.out | 4 +--
src/test/regress/expected/alter_table.out | 32 +++++++++----------
src/test/regress/expected/copy2.out | 2 +-
src/test/regress/expected/errors.out | 8 ++---
src/test/regress/expected/join.out | 12 +++----
src/test/regress/expected/namespace.out | 2 +-
src/test/regress/expected/numerology.out | 2 +-
src/test/regress/expected/plpgsql.out | 12 +++----
src/test/regress/expected/psql.out | 2 +-
src/test/regress/expected/rules.out | 2 +-
.../regress/expected/session_variables.out | 6 ++--
src/test/regress/expected/transactions.out | 4 +--
src/test/regress/expected/union.out | 2 +-
21 files changed, 87 insertions(+), 65 deletions(-)
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 5ddd3ebbaf8..d920afd97ca 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -115,7 +115,6 @@ static Node *make_nulltest_from_distinct(ParseState *pstate,
static Node *makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
char *attrname, bool fenced, int location);
-static bool session_variables_are_visible(ParseState *pstate);
/*
@@ -527,7 +526,7 @@ transformIndirection(ParseState *pstate, A_Indirection *ind)
* printed. When we are in an expression where session variables cannot be
* used, we raise the first form of error message.
*/
-static bool
+bool
expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
{
bool result = false;
@@ -1235,7 +1234,7 @@ transformVariableFence(ParseState *pstate, VariableFence *vf)
}
/* returns true, when session variables are visible without variable fence */
-static bool
+bool
session_variables_are_visible(ParseState *pstate)
{
switch (session_variables_visibility)
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index bec6947ea2d..be148f62c40 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -27,6 +27,7 @@
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "parser/parse_enr.h"
+#include "parser/parse_expr.h"
#include "parser/parse_relation.h"
#include "parser/parse_type.h"
#include "parser/parsetree.h"
@@ -3761,6 +3762,20 @@ errorMissingRTE(ParseState *pstate, RangeVar *relation)
parser_errposition(pstate, relation->location)));
}
+/*
+ * set message "column does not exist" or "column or variable does not exist"
+ * in dependency if expression context allows session variables.
+ */
+static int
+column_or_variable_does_not_exists(ParseState *pstate, const char *colname)
+{
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind) &&
+ session_variables_are_visible(pstate))
+ return errmsg("column or variable \"%s\" does not exist", colname);
+ else
+ return errmsg("column \"%s\" does not exist", colname);
+}
+
/*
* Generate a suitable error about a missing column.
*
@@ -3795,7 +3810,7 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errdetail("There are columns named \"%s\", but they are in tables that cannot be referenced from this part of the query.",
colname),
!relname ? errhint("Try using a table-qualified name.") : 0,
@@ -3805,7 +3820,7 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errdetail("There is a column named \"%s\" in table \"%s\", but it cannot be referenced from this part of the query.",
colname, state->rexact1->eref->aliasname),
rte_visible_if_lateral(pstate, state->rexact1) ?
@@ -3823,14 +3838,14 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
parser_errposition(pstate, location)));
/* Handle case where we have a single alternative spelling to offer */
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errhint("Perhaps you meant to reference the column \"%s.%s\".",
state->rfirst->eref->aliasname,
strVal(list_nth(state->rfirst->eref->colnames,
@@ -3844,7 +3859,7 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errhint("Perhaps you meant to reference the column \"%s.%s\" or the column \"%s.%s\".",
state->rfirst->eref->aliasname,
strVal(list_nth(state->rfirst->eref->colnames,
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index cf01bff65a9..2a527887a8d 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -779,7 +779,9 @@ transformAssignmentIndirection(ParseState *pstate,
if (!typrelid)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
- errmsg("cannot assign to field \"%s\" of column \"%s\" because its type %s is not a composite type",
+ errmsg(expr_kind_allows_session_variables(pstate->p_expr_kind) ?
+ "cannot assign to field \"%s\" of column or variable \"%s\" because its type %s is not a composite type" :
+ "cannot assign to field \"%s\" of column \"%s\" because its type %s is not a composite type",
strVal(n), targetName,
format_type_be(targetTypeId)),
parser_errposition(pstate, location)));
@@ -788,7 +790,9 @@ transformAssignmentIndirection(ParseState *pstate,
if (attnum == InvalidAttrNumber)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
- errmsg("cannot assign to field \"%s\" of column \"%s\" because there is no such column in data type %s",
+ errmsg(expr_kind_allows_session_variables(pstate->p_expr_kind) ?
+ "cannot assign to field \"%s\" of column or variable \"%s\" because there is no such column in data type %s" :
+ "cannot assign to field \"%s\" of column \"%s\" because there is no such column in data type %s",
strVal(n), targetName,
format_type_be(targetTypeId)),
parser_errposition(pstate, location)));
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index e2f8d832242..1eced5e6cf5 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -38,4 +38,8 @@ extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKin
extern const char *ParseExprKindName(ParseExprKind exprKind);
+extern bool expr_kind_allows_session_variables(ParseExprKind p_expr_kind);
+
+extern bool session_variables_are_visible(ParseState *pstate);
+
#endif /* PARSE_EXPR_H */
diff --git a/src/pl/plpgsql/src/expected/plpgsql_array.out b/src/pl/plpgsql/src/expected/plpgsql_array.out
index 4c6b3ce998a..ad6692c3e52 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_array.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_array.out
@@ -41,7 +41,7 @@ NOTICE: a = {"(,11)"}, a[1].i = 11
-- perhaps this ought to work, but for now it doesn't:
do $$ declare a complex[];
begin a[1:2].i := array[11,12]; raise notice 'a = %', a; end$$;
-ERROR: cannot assign to field "i" of column "a" because its type complex[] is not a composite type
+ERROR: cannot assign to field "i" of column or variable "a" because its type complex[] is not a composite type
LINE 1: a[1:2].i := array[11,12]
^
QUERY: a[1:2].i := array[11,12]
diff --git a/src/pl/plpgsql/src/expected/plpgsql_record.out b/src/pl/plpgsql/src/expected/plpgsql_record.out
index 6974c8f4a44..3970ac721c9 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_record.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_record.out
@@ -135,7 +135,7 @@ ERROR: record "c" has no field "x"
CONTEXT: PL/pgSQL assignment "c.x.q1 = 1"
PL/pgSQL function inline_code_block line 1 at assignment
do $$ declare c nested_int8s; begin c.c2.x = 1; end $$;
-ERROR: cannot assign to field "x" of column "c" because there is no such column in data type two_int8s
+ERROR: cannot assign to field "x" of column or variable "c" because there is no such column in data type two_int8s
LINE 1: c.c2.x = 1
^
QUERY: c.c2.x = 1
@@ -157,7 +157,7 @@ ERROR: record "c" has no field "x"
CONTEXT: PL/pgSQL assignment "b.c.x.q1 = 1"
PL/pgSQL function inline_code_block line 1 at assignment
do $$ <<b>> declare c nested_int8s; begin b.c.c2.x = 1; end $$;
-ERROR: cannot assign to field "x" of column "b" because there is no such column in data type two_int8s
+ERROR: cannot assign to field "x" of column or variable "b" because there is no such column in data type two_int8s
LINE 1: b.c.c2.x = 1
^
QUERY: b.c.c2.x = 1
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index ecac64fcfb4..8bd2b398bdd 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -232,7 +232,7 @@ SET ROLE TO DEFAULT;
SET ROLE TO regress_var_exec_role;
-- should fail, but not crash
SELECT var_read_func();
-ERROR: column "plpgsql_sv_var1" does not exist
+ERROR: column or variable "plpgsql_sv_var1" does not exist
LINE 1: plpgsql_sv_var1
^
QUERY: plpgsql_sv_var1
diff --git a/src/pl/tcl/expected/pltcl_queries.out b/src/pl/tcl/expected/pltcl_queries.out
index 35cc6e62aad..497cd38189b 100644
--- a/src/pl/tcl/expected/pltcl_queries.out
+++ b/src/pl/tcl/expected/pltcl_queries.out
@@ -450,12 +450,12 @@ CONTEXT: while executing
"__PLTcl_proc_tcl_eval_text spi_prepare\ a\ \"b\ \{\""
in PL/Tcl function tcl_eval(text)
select tcl_error_handling_test($tcl$spi_prepare "select moo" []$tcl$);
- tcl_error_handling_test
---------------------------------------
- SQLSTATE: 42703 +
- condition: undefined_column +
- cursor_position: 8 +
- message: column "moo" does not exist+
+ tcl_error_handling_test
+--------------------------------------------------
+ SQLSTATE: 42703 +
+ condition: undefined_column +
+ cursor_position: 8 +
+ message: column or variable "moo" does not exist+
statement: select moo
(1 row)
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
index e9a254bcd12..d8848d555cd 100644
--- a/src/test/isolation/expected/session-variable.out
+++ b/src/test/isolation/expected/session-variable.out
@@ -10,7 +10,7 @@ test
step drop: DROP VARIABLE myvar;
step val: SELECT myvar;
-ERROR: column "myvar" does not exist
+ERROR: column or variable "myvar" does not exist
starting permutation: let val s1 drop val sr1
step let: LET myvar = 'test';
@@ -23,7 +23,7 @@ test
step s1: BEGIN;
step drop: DROP VARIABLE myvar;
step val: SELECT myvar;
-ERROR: column "myvar" does not exist
+ERROR: column or variable "myvar" does not exist
step sr1: ROLLBACK;
starting permutation: let val dbg drop create dbg val
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 362f38856d2..299dbdb5e43 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -1298,19 +1298,19 @@ select * from atacc1;
(1 row)
select * from atacc1 order by a;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select * from atacc1 order by a;
^
select * from atacc1 order by "........pg.dropped.1........";
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select * from atacc1 order by "........pg.dropped.1........"...
^
select * from atacc1 group by a;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select * from atacc1 group by a;
^
select * from atacc1 group by "........pg.dropped.1........";
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select * from atacc1 group by "........pg.dropped.1........"...
^
select atacc1.* from atacc1;
@@ -1320,7 +1320,7 @@ select atacc1.* from atacc1;
(1 row)
select a from atacc1;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select a from atacc1;
^
select atacc1.a from atacc1;
@@ -1334,15 +1334,15 @@ select b,c,d from atacc1;
(1 row)
select a,b,c,d from atacc1;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select a,b,c,d from atacc1;
^
select * from atacc1 where a = 1;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select * from atacc1 where a = 1;
^
select "........pg.dropped.1........" from atacc1;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select "........pg.dropped.1........" from atacc1;
^
select atacc1."........pg.dropped.1........" from atacc1;
@@ -1350,11 +1350,11 @@ ERROR: column atacc1.........pg.dropped.1........ does not exist
LINE 1: select atacc1."........pg.dropped.1........" from atacc1;
^
select "........pg.dropped.1........",b,c,d from atacc1;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select "........pg.dropped.1........",b,c,d from atacc1;
^
select * from atacc1 where "........pg.dropped.1........" = 1;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select * from atacc1 where "........pg.dropped.1........" = ...
^
-- UPDATEs
@@ -1363,7 +1363,7 @@ ERROR: column "a" of relation "atacc1" does not exist
LINE 1: update atacc1 set a = 3;
^
update atacc1 set b = 2 where a = 3;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: update atacc1 set b = 2 where a = 3;
^
update atacc1 set "........pg.dropped.1........" = 3;
@@ -1371,7 +1371,7 @@ ERROR: column "........pg.dropped.1........" of relation "atacc1" does not exis
LINE 1: update atacc1 set "........pg.dropped.1........" = 3;
^
update atacc1 set b = 2 where "........pg.dropped.1........" = 3;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: update atacc1 set b = 2 where "........pg.dropped.1........"...
^
-- INSERTs
@@ -1419,11 +1419,11 @@ LINE 1: insert into atacc1 ("........pg.dropped.1........",b,c,d) va...
^
-- DELETEs
delete from atacc1 where a = 3;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: delete from atacc1 where a = 3;
^
delete from atacc1 where "........pg.dropped.1........" = 3;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: delete from atacc1 where "........pg.dropped.1........" = 3;
^
delete from atacc1;
@@ -1716,7 +1716,7 @@ select f1 from c1;
alter table c1 drop column f1;
select f1 from c1;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1 from c1;
^
HINT: Perhaps you meant to reference the column "c1.f2".
@@ -1730,7 +1730,7 @@ ERROR: cannot drop inherited column "f1"
alter table p1 drop column f1;
-- c1.f1 is dropped now, since there is no local definition for it
select f1 from c1;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1 from c1;
^
HINT: Perhaps you meant to reference the column "c1.f2".
diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 64ea33aeae8..6874f5ae0d1 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -160,7 +160,7 @@ LINE 1: COPY x TO stdout WHERE a = 1;
COPY x from stdin WHERE a = 50004;
COPY x from stdin WHERE a > 60003;
COPY x from stdin WHERE f > 60003;
-ERROR: column "f" does not exist
+ERROR: column or variable "f" does not exist
LINE 1: COPY x from stdin WHERE f > 60003;
^
COPY x from stdin WHERE a = max(x.b);
diff --git a/src/test/regress/expected/errors.out b/src/test/regress/expected/errors.out
index 8c527474daf..e53ae451dfc 100644
--- a/src/test/regress/expected/errors.out
+++ b/src/test/regress/expected/errors.out
@@ -27,7 +27,7 @@ LINE 1: select * from nonesuch;
^
-- bad name in target list
select nonesuch from pg_database;
-ERROR: column "nonesuch" does not exist
+ERROR: column or variable "nonesuch" does not exist
LINE 1: select nonesuch from pg_database;
^
-- empty distinct list isn't OK
@@ -37,17 +37,17 @@ LINE 1: select distinct from pg_database;
^
-- bad attribute name on lhs of operator
select * from pg_database where nonesuch = pg_database.datname;
-ERROR: column "nonesuch" does not exist
+ERROR: column or variable "nonesuch" does not exist
LINE 1: select * from pg_database where nonesuch = pg_database.datna...
^
-- bad attribute name on rhs of operator
select * from pg_database where pg_database.datname = nonesuch;
-ERROR: column "nonesuch" does not exist
+ERROR: column or variable "nonesuch" does not exist
LINE 1: ...ect * from pg_database where pg_database.datname = nonesuch;
^
-- bad attribute name in select distinct on
select distinct on (foobar) * from pg_database;
-ERROR: column "foobar" does not exist
+ERROR: column or variable "foobar" does not exist
LINE 1: select distinct on (foobar) * from pg_database;
^
-- grouping with FOR UPDATE
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index 3ffc066b1f8..6daff885128 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -6394,13 +6394,13 @@ LINE 1: select t2.uunique1 from
HINT: Perhaps you meant to reference the column "t2.unique1".
select uunique1 from
tenk1 t1 join tenk2 t2 on t1.two = t2.two; -- error, suggest both at once
-ERROR: column "uunique1" does not exist
+ERROR: column or variable "uunique1" does not exist
LINE 1: select uunique1 from
^
HINT: Perhaps you meant to reference the column "t1.unique1" or the column "t2.unique1".
select ctid from
tenk1 t1 join tenk2 t2 on t1.two = t2.two; -- error, need qualification
-ERROR: column "ctid" does not exist
+ERROR: column or variable "ctid" does not exist
LINE 1: select ctid from
^
DETAIL: There are columns named "ctid", but they are in tables that cannot be referenced from this part of the query.
@@ -7497,7 +7497,7 @@ lateral (select * from int8_tbl t1,
-- test some error cases where LATERAL should have been used but wasn't
select f1,g from int4_tbl a, (select f1 as g) ss;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1,g from int4_tbl a, (select f1 as g) ss;
^
DETAIL: There is a column named "f1" in table "a", but it cannot be referenced from this part of the query.
@@ -7509,7 +7509,7 @@ LINE 1: select f1,g from int4_tbl a, (select a.f1 as g) ss;
DETAIL: There is an entry for table "a", but it cannot be referenced from this part of the query.
HINT: To reference that table, you must mark this subquery with LATERAL.
select f1,g from int4_tbl a cross join (select f1 as g) ss;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1,g from int4_tbl a cross join (select f1 as g) ss;
^
DETAIL: There is a column named "f1" in table "a", but it cannot be referenced from this part of the query.
@@ -7546,7 +7546,7 @@ LINE 1: select 1 from tenk1 a, lateral (select max(a.unique1) from i...
create temp table xx1 as select f1 as x1, -f1 as x2 from int4_tbl;
-- error, can't do this:
update xx1 set x2 = f1 from (select * from int4_tbl where f1 = x1) ss;
-ERROR: column "x1" does not exist
+ERROR: column or variable "x1" does not exist
LINE 1: ... set x2 = f1 from (select * from int4_tbl where f1 = x1) ss;
^
DETAIL: There is a column named "x1" in table "xx1", but it cannot be referenced from this part of the query.
@@ -7566,7 +7566,7 @@ update xx1 set x2 = f1 from xx1, lateral (select * from int4_tbl where f1 = x1)
ERROR: table name "xx1" specified more than once
-- also errors:
delete from xx1 using (select * from int4_tbl where f1 = x1) ss;
-ERROR: column "x1" does not exist
+ERROR: column or variable "x1" does not exist
LINE 1: ...te from xx1 using (select * from int4_tbl where f1 = x1) ss;
^
DETAIL: There is a column named "x1" in table "xx1", but it cannot be referenced from this part of the query.
diff --git a/src/test/regress/expected/namespace.out b/src/test/regress/expected/namespace.out
index dbbda72d395..d98793f92a7 100644
--- a/src/test/regress/expected/namespace.out
+++ b/src/test/regress/expected/namespace.out
@@ -23,7 +23,7 @@ BEGIN;
SET search_path to public, test_ns_schema_1;
CREATE SCHEMA test_ns_schema_2
CREATE VIEW abc_view AS SELECT c FROM abc;
-ERROR: column "c" does not exist
+ERROR: column or variable "c" does not exist
LINE 2: CREATE VIEW abc_view AS SELECT c FROM abc;
^
COMMIT;
diff --git a/src/test/regress/expected/numerology.out b/src/test/regress/expected/numerology.out
index 9e23166fed1..672012e1461 100644
--- a/src/test/regress/expected/numerology.out
+++ b/src/test/regress/expected/numerology.out
@@ -314,7 +314,7 @@ NOTICE: i = 1002
NOTICE: i = 1003
-- error cases
SELECT _100;
-ERROR: column "_100" does not exist
+ERROR: column or variable "_100" does not exist
LINE 1: SELECT _100;
^
SELECT 100_;
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index 0a6945581bd..5c599ba312e 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -2598,7 +2598,7 @@ end; $$ language plpgsql;
-- should fail: SQLSTATE and SQLERRM are only in defined EXCEPTION
-- blocks
select excpt_test1();
-ERROR: column "sqlstate" does not exist
+ERROR: column or variable "sqlstate" does not exist
LINE 1: sqlstate
^
QUERY: sqlstate
@@ -2613,7 +2613,7 @@ begin
end; $$ language plpgsql;
-- should fail
select excpt_test2();
-ERROR: column "sqlstate" does not exist
+ERROR: column or variable "sqlstate" does not exist
LINE 1: sqlstate
^
QUERY: sqlstate
@@ -4675,7 +4675,7 @@ BEGIN
RAISE NOTICE '%, %', r.roomno, r.comment;
END LOOP;
END$$;
-ERROR: column "foo" does not exist
+ERROR: column or variable "foo" does not exist
LINE 1: SELECT rtrim(roomno) AS roomno, foo FROM Room ORDER BY roomn...
^
QUERY: SELECT rtrim(roomno) AS roomno, foo FROM Room ORDER BY roomno
@@ -4717,7 +4717,7 @@ begin
raise notice 'x = %', x;
end;
$$;
-ERROR: column "x" does not exist
+ERROR: column or variable "x" does not exist
LINE 1: x + 1
^
QUERY: x + 1
@@ -4729,7 +4729,7 @@ begin
raise notice 'x = %, y = %', x, y;
end;
$$;
-ERROR: column "x" does not exist
+ERROR: column or variable "x" does not exist
LINE 1: x + 1
^
QUERY: x + 1
@@ -5769,7 +5769,7 @@ ALTER TABLE alter_table_under_transition_tables
DROP column name;
UPDATE alter_table_under_transition_tables
SET id = id;
-ERROR: column "name" does not exist
+ERROR: column or variable "name" does not exist
LINE 1: (SELECT string_agg(id || '=' || name, ',') FROM d)
^
QUERY: (SELECT string_agg(id || '=' || name, ',') FROM d)
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 78aca67e452..ec870172faa 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -214,7 +214,7 @@ select $1::int as col \bind 1 \g \bind 2 \g
-- errors
-- parse error
SELECT foo \bind \g
-ERROR: column "foo" does not exist
+ERROR: column or variable "foo" does not exist
LINE 1: SELECT foo
^
-- tcop error
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 5baba8d39ff..f1b5b73a86a 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1191,7 +1191,7 @@ drop rule rules_foorule on rules_foo;
-- this should fail because f1 is not exposed for unqualified reference:
create rule rules_foorule as on insert to rules_foo where f1 < 100
do instead insert into rules_foo2 values (f1);
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 2: do instead insert into rules_foo2 values (f1);
^
DETAIL: There are columns named "f1", but they are in tables that cannot be referenced from this part of the query.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 22dbdfdb426..bfb9224c2d9 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -811,7 +811,7 @@ ERROR: session variable "var1" doesn't exist
LINE 1: LET var1 = pi();
^
SELECT var1;
-ERROR: column "var1" does not exist
+ERROR: column or variable "var1" does not exist
LINE 1: SELECT var1;
^
-- should be ok
@@ -1030,7 +1030,7 @@ SELECT v1;
-- should fail, attribute doesn't exist
LET v1.x = 10;
-ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1
+ERROR: cannot assign to field "x" of column or variable "v1" because there is no such column in data type t1
LINE 1: LET v1.x = 10;
^
-- should fail, don't allow multi column query
@@ -1750,7 +1750,7 @@ BEGIN;
DROP VARIABLE var1;
-- should fail
SELECT var1;
-ERROR: column "var1" does not exist
+ERROR: column or variable "var1" does not exist
LINE 1: SELECT var1;
^
ROLLBACK;
diff --git a/src/test/regress/expected/transactions.out b/src/test/regress/expected/transactions.out
index 7f5757e89c4..b05b16d94bf 100644
--- a/src/test/regress/expected/transactions.out
+++ b/src/test/regress/expected/transactions.out
@@ -256,7 +256,7 @@ SELECT * FROM trans_barbaz; -- should have 1
BEGIN;
SAVEPOINT one;
SELECT trans_foo;
-ERROR: column "trans_foo" does not exist
+ERROR: column or variable "trans_foo" does not exist
LINE 1: SELECT trans_foo;
^
ROLLBACK TO SAVEPOINT one;
@@ -305,7 +305,7 @@ BEGIN;
SAVEPOINT one;
INSERT INTO savepoints VALUES (5);
SELECT trans_foo;
-ERROR: column "trans_foo" does not exist
+ERROR: column or variable "trans_foo" does not exist
LINE 1: SELECT trans_foo;
^
COMMIT;
diff --git a/src/test/regress/expected/union.out b/src/test/regress/expected/union.out
index caa8fe70a05..1d3447e84dd 100644
--- a/src/test/regress/expected/union.out
+++ b/src/test/regress/expected/union.out
@@ -939,7 +939,7 @@ ORDER BY q2,q1;
-- This should fail, because q2 isn't a name of an EXCEPT output column
SELECT q1 FROM int8_tbl EXCEPT SELECT q2 FROM int8_tbl ORDER BY q2 LIMIT 1;
-ERROR: column "q2" does not exist
+ERROR: column or variable "q2" does not exist
LINE 1: ... int8_tbl EXCEPT SELECT q2 FROM int8_tbl ORDER BY q2 LIMIT 1...
^
DETAIL: There is a column named "q2" in table "*SELECT* 2", but it cannot be referenced from this part of the query.
--
2.48.1
[text/x-patch] v20250212-0022-pg_restore-A-variable.patch (2.8K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/4-v20250212-0022-pg_restore-A-variable.patch)
download | inline diff:
From 762522ca200c4caf568f1d92feafba34bb560c52 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sun, 21 Jul 2024 17:04:41 +0200
Subject: [PATCH 22/22] pg_restore -A, --variable
possibility to restore session variable specified by name
---
doc/src/sgml/ref/pg_restore.sgml | 11 +++++++++++
src/bin/pg_dump/pg_restore.c | 9 ++++++++-
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/doc/src/sgml/ref/pg_restore.sgml b/doc/src/sgml/ref/pg_restore.sgml
index b8b27e1719e..7a3a4eabe25 100644
--- a/doc/src/sgml/ref/pg_restore.sgml
+++ b/doc/src/sgml/ref/pg_restore.sgml
@@ -106,6 +106,17 @@ PostgreSQL documentation
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>-A <replaceable class="parameter">session_variable</replaceable></option></term>
+ <term><option>--variable=<replaceable class="parameter">session_variable</replaceable></option></term>
+ <listitem>
+ <para>
+ Restore a named session variable only. Multiple session variables may
+ be specified with multiple <option>-A</option> switches.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>-c</option></term>
<term><option>--clean</option></term>
diff --git a/src/bin/pg_dump/pg_restore.c b/src/bin/pg_dump/pg_restore.c
index c602272d7db..02becb4179a 100644
--- a/src/bin/pg_dump/pg_restore.c
+++ b/src/bin/pg_dump/pg_restore.c
@@ -106,6 +106,7 @@ main(int argc, char **argv)
{"trigger", 1, NULL, 'T'},
{"use-list", 1, NULL, 'L'},
{"username", 1, NULL, 'U'},
+ {"variable", 1, NULL, 'A'},
{"verbose", 0, NULL, 'v'},
{"single-transaction", 0, NULL, '1'},
@@ -156,7 +157,7 @@ main(int argc, char **argv)
}
}
- while ((c = getopt_long(argc, argv, "acCd:ef:F:h:I:j:lL:n:N:Op:P:RsS:t:T:U:vwWx1",
+ while ((c = getopt_long(argc, argv, "A:acCd:ef:F:h:I:j:lL:n:N:Op:P:RsS:t:T:U:vwWx1",
cmdopts, NULL)) != -1)
{
switch (c)
@@ -164,6 +165,11 @@ main(int argc, char **argv)
case 'a': /* Dump data only */
data_only = true;
break;
+ case 'A': /* vAriable */
+ opts->selTypes = 1;
+ opts->selVariable = 1;
+ simple_string_list_append(&opts->variableNames, optarg);
+ break;
case 'c': /* clean (i.e., drop) schema prior to create */
opts->dropSchema = 1;
break;
@@ -466,6 +472,7 @@ usage(const char *progname)
printf(_("\nOptions controlling the restore:\n"));
printf(_(" -a, --data-only restore only the data, no schema\n"));
+ printf(_(" -A, --variable=NAME restore named session variable\n"));
printf(_(" -c, --clean clean (drop) database objects before recreating\n"));
printf(_(" -C, --create create the target database\n"));
printf(_(" -e, --exit-on-error exit on error, default is to continue\n"));
--
2.48.1
[text/x-patch] v20250212-0021-transactional-variables.patch (37.3K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/5-v20250212-0021-transactional-variables.patch)
download | inline diff:
From f9bbbdca93886dbf01f1a58b68de1fc8c2a0fde5 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:11:33 +0100
Subject: [PATCH 21/22] transactional variables
This commit implements transactional variables. The content of transactional
session variables is sensitive to transactions and subtransactions. Any
transactional variable holds a history of values necessary for revert. This history
is cleaned (purged) when a) we read the variable, b) when the transaction is finished.
We don't try to purge, when the last modification of a variable is from
current subtransaction, or when purge was processed in current subtransaction.
This patch is based on my work from Feb 2020 and it is related to discussion
about features related to session variables. Now, when the all features are
separated to isolated patches I can revitalize this patch, because it doesn't
increase complexity of basic patches.
Unlike other patches, this patch is without any review at this moment (Feb 2024),
but the feature should be fully functional for people who are interested about
this feature (for testing).
---
doc/src/sgml/catalogs.sgml | 12 +
doc/src/sgml/ref/create_variable.sgml | 10 +-
src/backend/catalog/pg_variable.c | 4 +
src/backend/commands/session_variable.c | 301 +++++++++++++++++-
src/backend/parser/gram.y | 50 +--
src/bin/pg_dump/pg_dump.c | 10 +-
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_dump/t/002_pg_dump.pl | 36 +++
src/bin/psql/describe.c | 4 +-
src/bin/psql/tab-complete.in.c | 5 +
src/include/catalog/pg_variable.h | 3 +
src/include/nodes/parsenodes.h | 1 +
src/include/parser/kwlist.h | 1 +
src/test/regress/expected/psql.out | 36 +--
.../regress/expected/session_variables.out | 100 ++++++
src/test/regress/sql/session_variables.sql | 58 ++++
16 files changed, 587 insertions(+), 45 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index c7a8170ddf2..1217f8f8647 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9884,6 +9884,18 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry><structfield>varistransact</structfield></entry>
+ <entry><type>boolean</type></entry>
+ <entry></entry>
+ <entry>
+ True, when the variable is <quote>transactional</quote>. In the case
+ of a transaction rollback, transactional variables are reset to the
+ value they had when the transaction started. The default value is
+ <literal>false</literal>.
+ </entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>vareoxaction</structfield> <type>char</type>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index 3c3e6d55b69..1aadd3677e5 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -26,7 +26,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-CREATE [ { TEMPORARY | TEMP } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+CREATE [ { TEMPORARY | TEMP } ] [ { TRANSACTIONAL | TRANSACTION } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
[ NOT NULL ] [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
@@ -47,6 +47,14 @@ CREATE [ { TEMPORARY | TEMP } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replac
same as regular variables in procedural languages.
</para>
+ <para>
+ When a schema variable is created with a
+ <command>CREATE TRANSACTIONAL VARIABLE</command> command, the variables
+ content changes are transactional: in case of rollback, they are reset to
+ their value at the beginning of the transaction or the latest subtransaction.
+ The variable content is only hold in memory, and thus is not persistent.
+ </para>
+
<para>
Session variables are retrieved by the <command>SELECT</command>
command. Their value is set with the <command>LET</command> command.
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 0b6093a00ba..fa49e7233d5 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -42,6 +42,7 @@ static ObjectAddress create_variable(const char *varName,
bool if_not_exists,
bool not_null,
bool is_immutable,
+ bool is_transact,
Node *varDefexpr,
VariableXactEndAction varXactEndAction);
@@ -59,6 +60,7 @@ create_variable(const char *varName,
bool if_not_exists,
bool not_null,
bool is_immutable,
+ bool is_transact,
Node *varDefexpr,
VariableXactEndAction varXactEndAction)
{
@@ -123,6 +125,7 @@ create_variable(const char *varName,
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
values[Anum_pg_variable_varnotnull - 1] = BoolGetDatum(not_null);
values[Anum_pg_variable_varisimmutable - 1] = BoolGetDatum(is_immutable);
+ values[Anum_pg_variable_varistransact - 1] = BoolGetDatum(is_transact);
values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
if (varDefexpr)
@@ -267,6 +270,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
stmt->if_not_exists,
stmt->not_null,
stmt->is_immutable,
+ stmt->is_transact,
cooked_default,
stmt->XactEndAction);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 554b8795569..9b41ed1af62 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -47,6 +47,19 @@ typedef struct SVariableXActDropItem
SubTransactionId deleting_subid;
} SVariableXActDropItem;
+/*
+ * Used for transactional variables. Holds prev version.
+ */
+typedef struct PrevValue
+{
+ Datum value;
+ bool isnull;
+
+ SubTransactionId modify_subid;
+
+ struct PrevValue *prev_value;
+} PrevValue;
+
/*
* The values of session variables are stored in the backend's private memory
* in the dedicated memory context SVariableMemoryContext in binary format.
@@ -68,6 +81,25 @@ typedef struct SVariableData
bool isnull;
Datum value;
+ /*
+ * We don't need stack versions modified in same subtransaction.
+ * Used by transactional variables only. The value of transactional
+ * variable can be returned immediately when modify_subid is same
+ * like current subid.
+ */
+ SubTransactionId modify_subid;
+
+ /*
+ * When the modify_subid is different than current subid, then
+ * we need to recheck versions and throw versions related to
+ * reverted transactions. When purge_subid is same like current subid
+ * we can return the value of transaction variable without this
+ * recheck.
+ */
+ SubTransactionId purge_subid;
+
+ PrevValue *prev_value;
+
Oid typid;
int16 typlen;
bool typbyval;
@@ -86,6 +118,7 @@ typedef struct SVariableData
bool not_null;
bool is_immutable;
+ bool is_transact;
bool reset_at_eox;
@@ -125,6 +158,9 @@ static bool needs_validation = false;
*/
static bool has_session_variables_with_reset_at_eox = false;
+/* true, when transactional variables was modified */
+static bool has_modified_transactional_variables = false;
+
/*
* The content of dropped session variables is not removed immediately. If
* possible, we do that at the end of the transaction. But we cannot do that
@@ -140,6 +176,7 @@ static List *xact_drop_items = NIL;
static void register_session_variable_xact_drop(Oid varid);
static void unregister_session_variable_xact_drop(Oid varid);
+static bool purge_session_variable(SVariable svar);
/*
* Callback function for session variable invalidation.
@@ -292,8 +329,25 @@ unregister_session_variable_xact_drop(Oid varid)
* Release stored value, free memory
*/
static void
-free_session_variable_value(SVariable svar)
+free_session_variable_value(SVariable svar, bool deep_free)
{
+ if (deep_free)
+ {
+ PrevValue *prev_value = svar->prev_value;
+ PrevValue *next_value;
+
+ while (prev_value)
+ {
+ if (!svar->typbyval)
+ pfree(DatumGetPointer(prev_value->value));
+
+ next_value = prev_value->prev_value;
+ pfree(prev_value);
+
+ prev_value = next_value;
+ }
+ }
+
/* clean the current value */
if (!svar->isnull)
{
@@ -390,7 +444,7 @@ remove_invalid_session_variables(bool atEOX)
{
Oid varid = svar->varid;
- free_session_variable_value(svar);
+ free_session_variable_value(svar, true);
hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
svar = NULL;
}
@@ -426,6 +480,94 @@ remove_session_variables_with_reset_at_eox(void)
has_session_variables_with_reset_at_eox = false;
}
+/*
+ * remove prev values at eox
+ */
+static void
+remove_prev_values_at_eox(bool isCommit)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ if (!sessionvars)
+ return;
+
+ /* leave quckly, when there are not that variables */
+ if (!has_modified_transactional_variables)
+ return;
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (svar->is_transact && svar->modify_subid != InvalidSubTransactionId)
+ {
+ if (isCommit)
+ {
+ if (purge_session_variable(svar))
+ {
+ PrevValue *prev_value = svar->prev_value;
+
+ while (prev_value)
+ {
+ PrevValue *current_pv = prev_value;
+
+ if (!svar->typbyval && !current_pv->isnull)
+ pfree(DatumGetPointer(current_pv->value));
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+ }
+ }
+ else
+ {
+ hash_search(sessionvars, &svar->varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ }
+ else
+ {
+ PrevValue *prev_value = svar->prev_value;
+
+ while (prev_value)
+ {
+ PrevValue *current_pv = prev_value;
+
+ if (current_pv->modify_subid == InvalidSubTransactionId)
+ break;
+
+ if (!svar->typbyval && !current_pv->isnull)
+ pfree(DatumGetPointer(current_pv->value));
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+ }
+
+ if (prev_value)
+ {
+ svar->value = prev_value->value;
+ svar->isnull = prev_value->isnull;
+
+ pfree(prev_value);
+ }
+ else
+ {
+ hash_search(sessionvars, &svar->varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ }
+
+ /* when svar is still valid (not removed from sessionvars */
+ if (svar)
+ {
+ svar->modify_subid = InvalidSubTransactionId;
+ svar->prev_value = NULL;
+ }
+ }
+ }
+
+ has_modified_transactional_variables = false;
+}
+
/*
* Perform ON COMMIT DROP for temporary session variables,
* and remove all dropped variables from memory.
@@ -473,6 +615,8 @@ AtPreEOXact_SessionVariables(bool isCommit)
remove_invalid_session_variables(true);
}
+ remove_prev_values_at_eox(isCommit);
+
/*
* We have to clean xact_drop_items. All related variables are dropped
* now, or lost inside aborted transaction.
@@ -618,6 +762,7 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
svar->not_null = varform->varnotnull;
svar->is_immutable = varform->varisimmutable;
+ svar->is_transact = varform->varistransact;
svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
svar->domain_check_extra = NULL;
@@ -643,6 +788,17 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
svar->isnull = true;
svar->value = (Datum) 0;
+ if (svar->is_transact)
+ {
+ svar->modify_subid = GetCurrentSubTransactionId();
+ has_modified_transactional_variables = true;
+ }
+ else
+ svar->modify_subid = InvalidSubTransactionId;
+
+ svar->purge_subid = InvalidSubTransactionId;
+ svar->prev_value = NULL;
+
svar->is_valid = true;
svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
@@ -676,6 +832,69 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
ReleaseSysCache(tup);
}
+/*
+ * Try to remove all previous versions related to reverted transactions.
+ * Returns true, when valid version was found.
+ */
+static bool
+purge_session_variable(SVariable svar)
+{
+ SubTransactionId current_subid;
+ PrevValue *prev_value;
+ bool found = true;
+
+ Assert(svar->is_transact);
+
+ if (svar->modify_subid == InvalidSubTransactionId)
+ return true;
+
+ current_subid = GetCurrentSubTransactionId();
+
+ if (svar->modify_subid == current_subid)
+ return true;
+
+ if (svar->purge_subid == current_subid)
+ return true;
+
+ if (SubTransactionIsActive(svar->modify_subid))
+ {
+ svar->purge_subid = current_subid;
+ return true;
+ }
+
+ prev_value = svar->prev_value;
+
+ while (prev_value)
+ {
+ PrevValue *current_pv = prev_value;
+
+ if (current_pv->modify_subid == InvalidSubTransactionId ||
+ SubTransactionIsActive(current_pv->modify_subid))
+ {
+ svar->value = current_pv->value;
+ svar->isnull = current_pv->isnull;
+ svar->modify_subid = current_pv->modify_subid;
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+
+ found = true;
+ break;
+ }
+
+ if (!svar->typbyval && !current_pv->isnull)
+ pfree(DatumGetPointer(current_pv->value));
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+ }
+
+ svar->prev_value = prev_value;
+ svar->purge_subid = current_subid;
+
+ return found;
+}
+
/*
* Assign a new value to the session variable. It is copied to
* SVariableMemoryContext if necessary.
@@ -688,6 +907,10 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
Datum newval;
SVariableData locsvar,
*_svar;
+ SubTransactionId current_subid = GetCurrentSubTransactionId();
+ SubTransactionId prev_purge_subid = InvalidSubTransactionId;
+ bool save_prev_value;
+ PrevValue *prev_value;
Assert(svar);
Assert(!isnull || value == (Datum) 0);
@@ -723,6 +946,21 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
else
_svar = svar;
+ if (_svar->is_transact && _svar->create_lsn == svar->create_lsn)
+ {
+ Assert(svar->typid == _svar->typid);
+ Assert(svar->typbyval == _svar->typbyval);
+ Assert(svar->typlen == _svar->typlen);
+
+ save_prev_value = svar->modify_subid != current_subid;
+ prev_value = svar->prev_value;
+ }
+ else
+ {
+ save_prev_value = false;
+ prev_value = NULL;
+ }
+
if (!isnull)
{
MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
@@ -734,7 +972,37 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
else
newval = value;
- free_session_variable_value(svar);
+ if (save_prev_value)
+ {
+ volatile PrevValue *new_prev_value;
+
+ PG_TRY();
+ {
+ new_prev_value = MemoryContextAlloc(SVariableMemoryContext,
+ sizeof(PrevValue));
+ }
+ PG_CATCH();
+ {
+ /* release mem from persistent content */
+ if (newval != value)
+ pfree(DatumGetPointer(newval));
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
+
+ new_prev_value->value = svar->value;
+ new_prev_value->isnull = svar->isnull;
+ new_prev_value->modify_subid = svar->modify_subid;
+ new_prev_value->prev_value = prev_value;
+
+ prev_value = (PrevValue *) new_prev_value;
+ prev_purge_subid = svar->purge_subid;
+
+ has_modified_transactional_variables = true;
+
+ }
+ else
+ free_session_variable_value(svar, prev_value == NULL);
elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value",
get_namespace_name(get_session_variable_namespace(svar->varid)),
@@ -747,6 +1015,9 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
svar->value = newval;
svar->isnull = isnull;
+ svar->modify_subid = current_subid;
+ svar->purge_subid = prev_purge_subid;
+ svar->prev_value = prev_value;
/* don't allow more changes of value when variable is IMMUTABLE */
if (svar->is_immutable)
@@ -848,6 +1119,8 @@ get_session_variable(Oid varid)
else
svar->is_valid = false;
+reinit:
+
/*
* Force setup for not yet initialized variables or variables that cannot
* be validated.
@@ -880,6 +1153,28 @@ get_session_variable(Oid varid)
varid);
}
+ /*
+ * Transactional variables should be purged before (remove
+ * versions created by possibly reverted subtransactions).
+ */
+ if (svar->is_transact &&
+ svar->modify_subid != GetCurrentSubTransactionId() &&
+ svar->modify_subid != InvalidSubTransactionId)
+ {
+ if (!purge_session_variable(svar))
+ {
+ /* force reinit */
+ svar->is_valid = false;
+
+ /*
+ * In next iteration modify_subid should be
+ * InvalidSubTransactionId or current subid,
+ * so there is not risk of infinity cycle.
+ */
+ goto reinit;
+ }
+ }
+
/* ensure the returned data is still of the correct domain */
if (svar->is_domain)
{
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 8e86904b6aa..6a898a978f7 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -675,7 +675,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
json_object_constructor_null_clause_opt
json_array_constructor_null_clause_opt
-%type <boolean> OptNotNull OptImmutable
+%type <boolean> OptNotNull OptImmutable OptTransactional
/*
* Non-keyword token types. These are hard-wired into the "flex" lexer.
@@ -780,7 +780,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
SUBSCRIPTION SUBSTRING SUPPORT SYMMETRIC SYSID SYSTEM_P SYSTEM_USER
TABLE TABLES TABLESAMPLE TABLESPACE TARGET TEMP TEMPLATE TEMPORARY TEXT_P THEN
- TIES TIME TIMESTAMP TO TRAILING TRANSACTION TRANSFORM
+ TIES TIME TIMESTAMP TO TRAILING TRANSACTION TRANSACTIONAL TRANSFORM
TREAT TRIGGER TRIM TRUE_P
TRUNCATE TRUSTED TYPE_P TYPES_P
@@ -5274,31 +5274,33 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE OptTemp OptImmutable VARIABLE qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
+ CREATE OptTemp OptTransactional OptImmutable VARIABLE qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $5->relpersistence = $2;
- n->is_immutable = $3;
- n->variable = $5;
- n->typeName = $7;
- n->collClause = (CollateClause *) $8;
- n->not_null = $9;
- n->defexpr = $10;
- n->XactEndAction = $11;
+ $6->relpersistence = $2;
+ n->is_immutable = $4;
+ n->is_transact = $3;
+ n->variable = $6;
+ n->typeName = $8;
+ n->collClause = (CollateClause *) $9;
+ n->not_null = $10;
+ n->defexpr = $11;
+ n->XactEndAction = $12;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE OptTemp OptImmutable VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
+ | CREATE OptTemp OptTransactional OptImmutable VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $8->relpersistence = $2;
- n->is_immutable = $3;
- n->variable = $8;
- n->typeName = $10;
- n->collClause = (CollateClause *) $11;
- n->not_null = $12;
- n->defexpr = $13;
- n->XactEndAction = $14;
+ $9->relpersistence = $2;
+ n->is_immutable = $4;
+ n->is_transact = $3;
+ n->variable = $9;
+ n->typeName = $11;
+ n->collClause = (CollateClause *) $12;
+ n->not_null = $13;
+ n->defexpr = $14;
+ n->XactEndAction = $15;
n->if_not_exists = true;
$$ = (Node *) n;
}
@@ -5326,6 +5328,12 @@ OptImmutable: IMMUTABLE { $$ = true; }
| /* EMPTY */ { $$ = false; }
;
+OptTransactional:
+ TRANSACTION { $$ = true; }
+ | TRANSACTIONAL { $$ = true; }
+ | /* EMPTY */ { $$ = false; }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
@@ -18174,6 +18182,7 @@ unreserved_keyword:
| TEXT_P
| TIES
| TRANSACTION
+ | TRANSACTIONAL
| TRANSFORM
| TRIGGER
| TRUNCATE
@@ -18824,6 +18833,7 @@ bare_label_keyword:
| TIMESTAMP
| TRAILING
| TRANSACTION
+ | TRANSACTIONAL
| TRANSFORM
| TREAT
| TRIGGER
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 727f6a18f25..e391f8e1ba3 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5444,6 +5444,7 @@ getVariables(Archive *fout)
int i_varcollation;
int i_varnotnull;
int i_varisimmutable;
+ int i_varistransact;
int i_varacl;
int i_acldefault;
int i,
@@ -5466,6 +5467,7 @@ getVariables(Archive *fout)
" END AS varcollation,\n"
" v.varnotnull,\n"
" v.varisimmutable,\n"
+ " v.varistransact,\n"
" pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n"
" v.varowner, v.varacl,\n"
" acldefault('V', v.varowner) AS acldefault\n"
@@ -5488,6 +5490,7 @@ getVariables(Archive *fout)
i_varcollation = PQfnumber(res, "varcollation");
i_varnotnull = PQfnumber(res, "varnotnull");
i_varisimmutable = PQfnumber(res, "varisimmutable");
+ i_varistransact = PQfnumber(res, "varistransact");
i_varowner = PQfnumber(res, "varowner");
i_varacl = PQfnumber(res, "varacl");
@@ -5516,6 +5519,7 @@ getVariables(Archive *fout)
varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
varinfo[i].varnotnull = *(PQgetvalue(res, i, i_varnotnull)) == 't';
varinfo[i].varisimmutable = *(PQgetvalue(res, i, i_varisimmutable)) == 't';
+ varinfo[i].varistransact = *(PQgetvalue(res, i, i_varistransact)) == 't';
varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
@@ -5563,6 +5567,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
const char *vardefexpr;
const char *varxactendaction;
const char *varisimmutable;
+ const char *varistransact;
Oid varcollation;
bool varnotnull;
@@ -5580,12 +5585,13 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
varcollation = varinfo->varcollation;
varnotnull = varinfo->varnotnull;
varisimmutable = varinfo->varisimmutable ? "IMMUTABLE " : "";
+ varistransact = varinfo->varistransact ? "TRANSACTIONAL " : "";
appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
qualvarname);
- appendPQExpBuffer(query, "CREATE %sVARIABLE %s AS %s",
- varisimmutable, qualvarname, vartypname);
+ appendPQExpBuffer(query, "CREATE %s%sVARIABLE %s AS %s",
+ varistransact, varisimmutable, qualvarname, vartypname);
if (OidIsValid(varcollation))
{
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index 0ae406f8551..12af34547c1 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -724,6 +724,7 @@ typedef struct _VariableInfo
const char *rolname; /* name of owner, or empty string */
bool varnotnull;
bool varisimmutable;
+ bool varistransact;
} VariableInfo;
/*
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 5f80bd4e79a..e00a979ee6a 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4144,6 +4144,42 @@ my %tests = (
},
},
+ 'CREATE TRANSACTIONAL VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE TRANSACTIONAL VARIABLE dump_test.variable8 AS integer',
+ regexp => qr/^
+ \QCREATE TRANSACTIONAL VARIABLE dump_test.variable8 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
+ 'CREATE TRANSACTIONAL IMMUTABLE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE TRANSACTIONAL IMMUTABLE VARIABLE dump_test.variable9 AS integer',
+ regexp => qr/^
+ \QCREATE TRANSACTIONAL IMMUTABLE VARIABLE dump_test.variable9 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 07835aa2bab..119986886e8 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5354,6 +5354,7 @@ listVariables(const char *pattern, bool verbose)
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
" NOT v.varnotnull as \"%s\",\n"
" NOT v.varisimmutable as \"%s\",\n"
+ " v.varistransact as \"%s\",\n"
" pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
@@ -5366,6 +5367,7 @@ listVariables(const char *pattern, bool verbose)
gettext_noop("Owner"),
gettext_noop("Nullable"),
gettext_noop("Mutable"),
+ gettext_noop("Transactional"),
gettext_noop("Default"),
gettext_noop("Transactional end action"));
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index f547bce1a10..c46078a700e 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1305,6 +1305,8 @@ static const pgsql_thing_t words_after_create[] = {
* TABLE ... */
{"TEXT SEARCH", NULL, NULL, NULL},
{"TRANSFORM", NULL, NULL, NULL, NULL, THING_NO_ALTER},
+ {"TRANSACTIONAL", NULL, NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE TRANSACTIONAL
+ * VARIABLE ... */
{"TRIGGER", "SELECT tgname FROM pg_catalog.pg_trigger WHERE tgname LIKE '%s' AND NOT tgisinternal"},
{"TYPE", NULL, NULL, &Query_for_list_of_datatypes},
{"UNIQUE", NULL, NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE UNIQUE
@@ -3966,8 +3968,11 @@ match_previous_words(int pattern_id,
}
/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE VARIABLE <name> with AS */
+ else if (Matches("CREATE", "TRANSACTION|TRANSACTIONAL"))
+ COMPLETE_WITH("IMMUTABLE", "VARIABLE");
else if (TailMatches("CREATE", "VARIABLE", MatchAny) ||
TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny) ||
+ TailMatches("TRANSACTION|TRANSACTIONAL", "VARIABLE", MatchAny) ||
TailMatches("IMMUTABLE", "VARIABLE", MatchAny))
COMPLETE_WITH("AS");
else if (TailMatches("VARIABLE", MatchAny, "AS"))
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index cf21e0426a7..454bb297097 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -62,6 +62,9 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* don't allow changes */
bool varisimmutable BKI_DEFAULT(f);
+ /* supports transactions */
+ bool varistransact BKI_DEFAULT(f);
+
/* action on transaction end */
char varxactendaction BKI_DEFAULT(n);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 263b63a37af..d72d12d820f 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3539,6 +3539,7 @@ typedef struct CreateSessionVarStmt
bool if_not_exists; /* do nothing if it already exists */
bool not_null; /* disallow nulls */
bool is_immutable; /* don't allow changes */
+ bool is_transact; /* supports transactions */
Node *defexpr; /* default expression */
char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 431167f6b43..e19b957739f 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -456,6 +456,7 @@ PG_KEYWORD("timestamp", TIMESTAMP, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("to", TO, RESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("trailing", TRAILING, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("transaction", TRANSACTION, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("transactional", TRANSACTIONAL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("transform", TRANSFORM, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("treat", TREAT, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("trigger", TRIGGER, UNRESERVED_KEYWORD, BARE_LABEL)
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index ec870172faa..061307621cd 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6020,20 +6020,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | t | t | | | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------------+---------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | f | | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | t | t | | | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------------+---------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | f | | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6501,9 +6501,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
---------+------+------+-----------+-------+----------+---------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------------+---------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6676,9 +6676,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
---------+------+------+-----------+-------+----------+---------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------------+---------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6815,9 +6815,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
---------+------+------+-----------+-------+----------+---------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------------+---------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index bfb9224c2d9..c283fe48ca6 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2592,3 +2592,103 @@ SELECT var1;
LET var1 = 30;
ERROR: session variable "public.var1" is declared IMMUTABLE
DROP VARIABLE var1;
+-- test transactional variables
+CREATE TRANSACTION VARIABLE tv AS int DEFAULT 0;
+BEGIN;
+ LET tv = 100;
+ SELECT tv;
+ tv
+-----
+ 100
+(1 row)
+
+ROLLBACK;
+SELECT tv;
+ tv
+----
+ 0
+(1 row)
+
+LET tv = 100;
+BEGIN;
+ LET tv = 1000;
+COMMIT;
+SELECT tv;
+ tv
+------
+ 1000
+(1 row)
+
+BEGIN;
+ LET tv = 0;
+ SELECT tv;
+ tv
+----
+ 0
+(1 row)
+
+ROLLBACK;
+SELECT tv;
+ tv
+------
+ 1000
+(1 row)
+
+-- test subtransactions
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ tv
+----
+ 2
+(1 row)
+
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+ tv
+----
+ 1
+(1 row)
+
+ROLLBACK;
+SELECT tv;
+ tv
+------
+ 1000
+(1 row)
+
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ tv
+----
+ 2
+(1 row)
+
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+ tv
+----
+ 1
+(1 row)
+
+COMMIT;
+SELECT tv;
+ tv
+----
+ 1
+(1 row)
+
+DROP VARIABLE tv;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index a54665dd10b..c375dd8b19e 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1808,3 +1808,61 @@ SELECT var1;
LET var1 = 30;
DROP VARIABLE var1;
+
+-- test transactional variables
+CREATE TRANSACTION VARIABLE tv AS int DEFAULT 0;
+
+BEGIN;
+ LET tv = 100;
+ SELECT tv;
+ROLLBACK;
+
+SELECT tv;
+
+LET tv = 100;
+BEGIN;
+ LET tv = 1000;
+COMMIT;
+
+SELECT tv;
+
+BEGIN;
+ LET tv = 0;
+ SELECT tv;
+ROLLBACK;
+
+SELECT tv;
+
+-- test subtransactions
+
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+ROLLBACK;
+
+SELECT tv;
+
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+COMMIT;
+
+SELECT tv;
+
+DROP VARIABLE tv;
--
2.48.1
[text/x-patch] v20250212-0019-expression-with-session-variables-can-be-inlined.patch (4.2K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/6-v20250212-0019-expression-with-session-variables-can-be-inlined.patch)
download | inline diff:
From d7649dc4c6c29eec32605abc0b34f2c5234bf54a Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sat, 20 Jan 2024 20:35:38 +0100
Subject: [PATCH 19/22] expression with session variables can be inlined
There is not an reason why session variables should to block inlining.
(of SQL functions). I can imagine some use cases like wrapping, and
inlining significantly reduces an overhead of SQL functions.
---
src/backend/optimizer/util/clauses.c | 37 ++++++++++++++-----
.../regress/expected/session_variables.out | 7 ++--
2 files changed, 30 insertions(+), 14 deletions(-)
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 175390c6c28..0eb52fa2081 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -4744,8 +4744,7 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
querytree->limitOffset ||
querytree->limitCount ||
querytree->setOperations ||
- (list_length(querytree->targetList) != 1) ||
- querytree->hasSessionVariables)
+ (list_length(querytree->targetList) != 1))
goto fail;
/* If the function result is composite, resolve it */
@@ -4949,21 +4948,39 @@ substitute_actual_parameters_mutator(Node *node,
{
if (node == NULL)
return NULL;
+
+
+ /*
+ * SQL functions can contain two different kind of params. The nodes with
+ * paramkind PARAM_EXTERN are related to function's arguments (and should
+ * be replaced in this step), because this is how we apply the function's
+ * arguments for an expression.
+ *
+ * The nodes with paramkind PARAM_VARIABLE are related to usage of session
+ * variables. The values of session variables are not passed to expression
+ * by expression arguments, so it should not be replaced here by
+ * function's arguments.
+ */
if (IsA(node, Param))
{
Param *param = (Param *) node;
- if (param->paramkind != PARAM_EXTERN)
+ if (param->paramkind != PARAM_EXTERN &&
+ param->paramkind != PARAM_VARIABLE)
elog(ERROR, "unexpected paramkind: %d", (int) param->paramkind);
- if (param->paramid <= 0 || param->paramid > context->nargs)
- elog(ERROR, "invalid paramid: %d", param->paramid);
- /* Count usage of parameter */
- context->usecounts[param->paramid - 1]++;
+ if (param->paramkind == PARAM_EXTERN)
+ {
+ if (param->paramid <= 0 || param->paramid > context->nargs)
+ elog(ERROR, "invalid paramid: %d", param->paramid);
- /* Select the appropriate actual arg and replace the Param with it */
- /* We don't need to copy at this time (it'll get done later) */
- return list_nth(context->args, param->paramid - 1);
+ /* Count usage of parameter */
+ context->usecounts[param->paramid - 1]++;
+
+ /* Select the appropriate actual arg and replace the Param with it */
+ /* We don't need to copy at this time (it'll get done later) */
+ return list_nth(context->args, param->paramid - 1);
+ }
}
return expression_tree_mutator(node, substitute_actual_parameters_mutator, context);
}
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 2690ce9d309..22dbdfdb426 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -480,7 +480,6 @@ SELECT var1;
ERROR: permission denied for session variable var1
SELECT sqlfx(20);
ERROR: permission denied for session variable var1
-CONTEXT: SQL function "sqlfx" statement 1
SELECT plpgsqlfx(20);
ERROR: permission denied for session variable var1
CONTEXT: PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
@@ -587,10 +586,10 @@ SELECT sqlfx1(sqlfx2('Hello'));
-- inlining is blocked
EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
- QUERY PLAN
-------------------------------------------------------
+ QUERY PLAN
+-----------------------------------------------------------------------------
Result
- Output: sqlfx1(sqlfx2('Hello'::character varying))
+ Output: ((var1 || ', '::text) || ((var2 || ', '::text) || 'Hello'::text))
(2 rows)
DROP FUNCTION sqlfx1(varchar);
--
2.48.1
[text/x-patch] v20250212-0018-plpgsql-implementation-for-LET-statement.patch (16.8K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/7-v20250212-0018-plpgsql-implementation-for-LET-statement.patch)
download | inline diff:
From 4f70fb5c724e279836c7208608ab86d7ff3495ca Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sat, 20 Jan 2024 08:56:17 +0100
Subject: [PATCH 18/22] plpgsql implementation for LET statement
PLpgSQL allows to call expression executor directly (for simple expression).
This possibility strongly reduces overhead related to execution. Reimplementation
of LET statement (inside PLpgSQL) allows to use this possibility, and strongly
increase performance:
CREATE VARIABLE svar int;
DO $$
BEGIN
FOR i IN 1..10000
LOOP
LET svar = i;
END LOOP;
END;
$$;
From 120ms to 8ms (with assertions) (this is best case, but without it, the LET statement
can be bottle neck).
An alternative can be reimplementation of LET statement inside expression
executor, and then SQL LET command can be executed in simple expression
execution, but this increase an complexity of executor, but still the
benefits is only inside plpgsql, so it is better to this optimization
inside plpgsql.
---
src/backend/commands/session_variable.c | 16 ++++++
src/backend/executor/spi.c | 3 +
src/backend/parser/analyze.c | 12 ++++
src/backend/parser/gram.y | 8 +++
src/backend/parser/parser.c | 1 +
src/include/commands/session_variable.h | 1 +
src/include/nodes/parsenodes.h | 2 +
src/include/parser/parser.h | 4 ++
src/pl/plpgsql/src/pl_exec.c | 56 +++++++++++++++++++
src/pl/plpgsql/src/pl_funcs.c | 21 +++++++
src/pl/plpgsql/src/pl_gram.y | 29 +++++++++-
src/pl/plpgsql/src/pl_reserved_kwlist.h | 1 +
src/pl/plpgsql/src/pl_unreserved_kwlist.h | 1 +
src/pl/plpgsql/src/plpgsql.h | 12 ++++
.../regress/expected/session_variables.out | 6 +-
src/tools/pgindent/typedefs.list | 1 +
16 files changed, 169 insertions(+), 5 deletions(-)
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 367751ed344..554b8795569 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -948,6 +948,22 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
set_session_variable(svar, value, isNull);
}
+/*
+ * Wrapper around SetSessionVariable with permission checks.
+ */
+void
+SetSessionVariableWithSecurityCheck(Oid varid, Datum value, bool isNull)
+{
+ AclResult aclresult;
+
+ /* is the caller allowed to update the session variable? */
+ aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid));
+
+ SetSessionVariable(varid, value, isNull);
+}
+
/*
* Returns a copy of the value stored in a variable.
*/
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index ecb2e4ccaa1..a775d4fb3bd 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -2991,6 +2991,9 @@ _SPI_error_callback(void *arg)
case RAW_PARSE_PLPGSQL_ASSIGN3:
errcontext("PL/pgSQL assignment \"%s\"", query);
break;
+ case RAW_PARSE_PLPGSQL_LET:
+ errcontext("LET statement \"%s\"", query);
+ break;
default:
errcontext("SQL statement \"%s\"", query);
break;
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 46a22ff5c94..2de0d23c8e3 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -2012,6 +2012,18 @@ transformLetStmt(ParseState *pstate, LetStmt *stmt)
stmt->query = (Node *) query;
+ /*
+ * Inside PL/pgSQL we don't want to execute LET statement as utility
+ * command, because it disallow to execute expression as simple
+ * expression. So for PL/pgSQL we have extra path, and we return SELECT.
+ * Then it can be executed by exec_eval_expr. Result is dirrectly assigned
+ * to target session variable inside PL/pgSQL LET statement handler. This
+ * is extra code, extra path, but possibility to get faster execution is
+ * too attractive.
+ */
+ if (stmt->plpgsql_mode)
+ return query;
+
/* represent the command as a utility Query */
result = makeNode(Query);
result->commandType = CMD_UTILITY;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 11ae96a4397..8e86904b6aa 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -824,6 +824,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%token MODE_PLPGSQL_ASSIGN1
%token MODE_PLPGSQL_ASSIGN2
%token MODE_PLPGSQL_ASSIGN3
+%token MODE_PLPGSQL_LET
/* Precedence: lowest to highest */
@@ -955,6 +956,13 @@ parse_toplevel:
pg_yyget_extra(yyscanner)->parsetree =
list_make1(makeRawStmt((Node *) n, @2));
}
+ | MODE_PLPGSQL_LET LetStmt
+ {
+ LetStmt *n = (LetStmt *) $2;
+ n->plpgsql_mode = true;
+ pg_yyget_extra(yyscanner)->parsetree =
+ list_make1(makeRawStmt((Node *) n, 0));
+ }
;
/*
diff --git a/src/backend/parser/parser.c b/src/backend/parser/parser.c
index 33a040506b4..887212aefde 100644
--- a/src/backend/parser/parser.c
+++ b/src/backend/parser/parser.c
@@ -62,6 +62,7 @@ raw_parser(const char *str, RawParseMode mode)
[RAW_PARSE_PLPGSQL_ASSIGN1] = MODE_PLPGSQL_ASSIGN1,
[RAW_PARSE_PLPGSQL_ASSIGN2] = MODE_PLPGSQL_ASSIGN2,
[RAW_PARSE_PLPGSQL_ASSIGN3] = MODE_PLPGSQL_ASSIGN3,
+ [RAW_PARSE_PLPGSQL_LET] = MODE_PLPGSQL_LET,
};
yyextra.have_lookahead = true;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index f66b6c0b864..b89728ead5a 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -28,6 +28,7 @@ extern void AtEOSubXact_SessionVariables(bool isCommit, SubTransactionId mySubid
SubTransactionId parentSubid);
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
+extern void SetSessionVariableWithSecurityCheck(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
extern Datum GetSessionVariableWithTypeid(Oid varid, bool *isNull, Oid *typid);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 6bcaf480576..263b63a37af 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2168,6 +2168,8 @@ typedef struct LetStmt
NodeTag type;
List *target; /* target variable */
Node *query; /* source expression */
+ bool plpgsql_mode; /* true, when command will be executed
+ * (parsed) by plpgsql runtime */
ParseLoc location;
} LetStmt;
diff --git a/src/include/parser/parser.h b/src/include/parser/parser.h
index 350196cd641..c8d5e8dbf92 100644
--- a/src/include/parser/parser.h
+++ b/src/include/parser/parser.h
@@ -33,6 +33,9 @@
* RAW_PARSE_PLPGSQL_ASSIGNn: parse a PL/pgSQL assignment statement,
* and return a one-element List containing a RawStmt node. "n"
* gives the number of dotted names comprising the target ColumnRef.
+ *
+ * RAW_PARSE_PLPGSQL_LET: parse a LET statement, and return a
+ * one-element List containing a RawStmt node.
*/
typedef enum
{
@@ -42,6 +45,7 @@ typedef enum
RAW_PARSE_PLPGSQL_ASSIGN1,
RAW_PARSE_PLPGSQL_ASSIGN2,
RAW_PARSE_PLPGSQL_ASSIGN3,
+ RAW_PARSE_PLPGSQL_LET,
} RawParseMode;
/* Values for the backslash_quote GUC */
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index d4377ceecbf..05eb4ac4f32 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -22,6 +22,7 @@
#include "access/tupconvert.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "commands/session_variable.h"
#include "executor/execExpr.h"
#include "executor/spi.h"
#include "executor/tstoreReceiver.h"
@@ -333,6 +334,8 @@ static int exec_stmt_commit(PLpgSQL_execstate *estate,
PLpgSQL_stmt_commit *stmt);
static int exec_stmt_rollback(PLpgSQL_execstate *estate,
PLpgSQL_stmt_rollback *stmt);
+static int exec_stmt_let(PLpgSQL_execstate *estate,
+ PLpgSQL_stmt_let *let);
static void plpgsql_estate_setup(PLpgSQL_execstate *estate,
PLpgSQL_function *func,
@@ -2132,6 +2135,10 @@ exec_stmts(PLpgSQL_execstate *estate, List *stmts)
rc = exec_stmt_rollback(estate, (PLpgSQL_stmt_rollback *) stmt);
break;
+ case PLPGSQL_STMT_LET:
+ rc = exec_stmt_let(estate, (PLpgSQL_stmt_let *) stmt);
+ break;
+
default:
/* point err_stmt to parent, since this one seems corrupt */
estate->err_stmt = save_estmt;
@@ -5009,6 +5016,55 @@ exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt)
return PLPGSQL_RC_OK;
}
+/* ----------
+ * exec_stmt_let Evaluate an expression and
+ * put the result into a session variable.
+ * ----------
+ */
+static int
+exec_stmt_let(PLpgSQL_execstate *estate, PLpgSQL_stmt_let *stmt)
+{
+ bool isNull;
+ Oid valtype;
+ int32 valtypmod;
+ Datum value;
+ Oid varid;
+
+ List *plansources;
+ CachedPlanSource *plansource;
+
+ value = exec_eval_expr(estate,
+ stmt->expr,
+ &isNull,
+ &valtype,
+ &valtypmod);
+
+ /*
+ * Oid of target session variable is stored in Query structure. It is
+ * safer to read this value directly from the plan than to hold this value
+ * in the plpgsql context, because it's not necessary to handle
+ * invalidation of the cached value. Next operations are read only without
+ * any allocations, so we can expect that retrieving varid from Query
+ * should be fast.
+ */
+ plansources = SPI_plan_get_plan_sources(stmt->expr->plan);
+ if (list_length(plansources) != 1)
+ elog(ERROR, "unexpected length of plansources of query for LET statement");
+
+ plansource = (CachedPlanSource *) linitial(plansources);
+ if (list_length(plansource->query_list) != 1)
+ elog(ERROR, "unexpected length of plansource of query for LET statement");
+
+ varid = linitial_node(Query, plansource->query_list)->resultVariable;
+ if (!OidIsValid(varid))
+ elog(ERROR, "oid of target session variable is not valid");
+
+ SetSessionVariableWithSecurityCheck(varid, value, isNull);
+ exec_eval_cleanup(estate);
+
+ return PLPGSQL_RC_OK;
+}
+
/* ----------
* exec_assign_expr Put an expression's result into a variable.
* ----------
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index 6b5394fc5fa..242b57f76de 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -288,6 +288,8 @@ plpgsql_stmt_typename(PLpgSQL_stmt *stmt)
return "COMMIT";
case PLPGSQL_STMT_ROLLBACK:
return "ROLLBACK";
+ case PLPGSQL_STMT_LET:
+ return "LET";
}
return "unknown";
@@ -585,6 +587,13 @@ plpgsql_statement_tree_walker_impl(PLpgSQL_stmt *stmt,
E_WALK(cstmt->expr);
break;
}
+ case PLPGSQL_STMT_LET:
+ {
+ PLpgSQL_stmt_let *lstmt = (PLpgSQL_stmt_let *) stmt;
+
+ E_WALK(lstmt->expr);
+ break;
+ }
case PLPGSQL_STMT_COMMIT:
case PLPGSQL_STMT_ROLLBACK:
{
@@ -806,6 +815,7 @@ static void dump_perform(PLpgSQL_stmt_perform *stmt);
static void dump_call(PLpgSQL_stmt_call *stmt);
static void dump_commit(PLpgSQL_stmt_commit *stmt);
static void dump_rollback(PLpgSQL_stmt_rollback *stmt);
+static void dump_let(PLpgSQL_stmt_let *stmt);
static void dump_expr(PLpgSQL_expr *expr);
@@ -905,6 +915,9 @@ dump_stmt(PLpgSQL_stmt *stmt)
case PLPGSQL_STMT_ROLLBACK:
dump_rollback((PLpgSQL_stmt_rollback *) stmt);
break;
+ case PLPGSQL_STMT_LET:
+ dump_let((PLpgSQL_stmt_let *) stmt);
+ break;
default:
elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
break;
@@ -1581,6 +1594,14 @@ dump_getdiag(PLpgSQL_stmt_getdiag *stmt)
printf("\n");
}
+static void
+dump_let(PLpgSQL_stmt_let *stmt)
+{
+ dump_ind();
+ dump_expr(stmt->expr);
+ printf("\n");
+}
+
static void
dump_expr(PLpgSQL_expr *expr)
{
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index 8048e040f81..980ebb56a45 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -210,7 +210,7 @@ static void check_raise_parameters(PLpgSQL_stmt_raise *stmt);
%type <stmt> stmt_return stmt_raise stmt_assert stmt_execsql
%type <stmt> stmt_dynexecute stmt_for stmt_perform stmt_call stmt_getdiag
%type <stmt> stmt_open stmt_fetch stmt_move stmt_close stmt_null
-%type <stmt> stmt_commit stmt_rollback
+%type <stmt> stmt_commit stmt_rollback stmt_let
%type <stmt> stmt_case stmt_foreach_a
%type <list> proc_exceptions
@@ -317,6 +317,7 @@ static void check_raise_parameters(PLpgSQL_stmt_raise *stmt);
%token <keyword> K_INTO
%token <keyword> K_IS
%token <keyword> K_LAST
+%token <keyword> K_LET
%token <keyword> K_LOG
%token <keyword> K_LOOP
%token <keyword> K_MERGE
@@ -891,6 +892,8 @@ proc_stmt : pl_block ';'
{ $$ = $1; }
| stmt_rollback
{ $$ = $1; }
+ | stmt_let
+ { $$ = $1; }
;
stmt_perform : K_PERFORM
@@ -1010,6 +1013,30 @@ stmt_assign : T_DATUM
}
;
+stmt_let : K_LET
+ {
+ PLpgSQL_stmt_let *new;
+ RawParseMode pmode;
+
+ pmode = RAW_PARSE_PLPGSQL_LET;
+
+ new = palloc0(sizeof(PLpgSQL_stmt_let));
+ new->cmd_type = PLPGSQL_STMT_LET;
+ new->lineno = plpgsql_location_to_lineno(@1, yyscanner);
+ new->stmtid = ++plpgsql_curr_compile->nstatements;
+
+ /* push back the head name to include it in the stmt */
+ plpgsql_push_back_token(K_LET, &yylval, &yylloc, yyscanner);
+ new->expr = read_sql_construct(';', 0, 0, ";",
+ pmode,
+ false, true,
+ NULL, NULL,
+ &yylval, &yylloc, yyscanner);
+
+ $$ = (PLpgSQL_stmt *)new;
+ }
+ ;
+
stmt_getdiag : K_GET getdiag_area_opt K_DIAGNOSTICS getdiag_list ';'
{
PLpgSQL_stmt_getdiag *new;
diff --git a/src/pl/plpgsql/src/pl_reserved_kwlist.h b/src/pl/plpgsql/src/pl_reserved_kwlist.h
index ce7b0c9d331..e266bd1cc46 100644
--- a/src/pl/plpgsql/src/pl_reserved_kwlist.h
+++ b/src/pl/plpgsql/src/pl_reserved_kwlist.h
@@ -40,6 +40,7 @@ PG_KEYWORD("from", K_FROM)
PG_KEYWORD("if", K_IF)
PG_KEYWORD("in", K_IN)
PG_KEYWORD("into", K_INTO)
+PG_KEYWORD("let", K_LET)
PG_KEYWORD("loop", K_LOOP)
PG_KEYWORD("not", K_NOT)
PG_KEYWORD("null", K_NULL)
diff --git a/src/pl/plpgsql/src/pl_unreserved_kwlist.h b/src/pl/plpgsql/src/pl_unreserved_kwlist.h
index 98f99ec470c..ed14fd86c31 100644
--- a/src/pl/plpgsql/src/pl_unreserved_kwlist.h
+++ b/src/pl/plpgsql/src/pl_unreserved_kwlist.h
@@ -69,6 +69,7 @@ PG_KEYWORD("info", K_INFO)
PG_KEYWORD("insert", K_INSERT)
PG_KEYWORD("is", K_IS)
PG_KEYWORD("last", K_LAST)
+PG_KEYWORD("let", K_LET)
PG_KEYWORD("log", K_LOG)
PG_KEYWORD("merge", K_MERGE)
PG_KEYWORD("message", K_MESSAGE)
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index d73996e09c0..c7538612f1a 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -128,6 +128,7 @@ typedef enum PLpgSQL_stmt_type
PLPGSQL_STMT_CALL,
PLPGSQL_STMT_COMMIT,
PLPGSQL_STMT_ROLLBACK,
+ PLPGSQL_STMT_LET,
} PLpgSQL_stmt_type;
/*
@@ -542,6 +543,17 @@ typedef struct PLpgSQL_stmt_assign
PLpgSQL_expr *expr;
} PLpgSQL_stmt_assign;
+/*
+ * Let statement
+ */
+typedef struct PLpgSQL_stmt_let
+{
+ PLpgSQL_stmt_type cmd_type;
+ int lineno;
+ unsigned int stmtid;
+ PLpgSQL_expr *expr;
+} PLpgSQL_stmt_let;
+
/*
* PERFORM statement
*/
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 3ee20b2643d..2690ce9d309 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1129,8 +1129,7 @@ ERROR: permission denied for session variable var1
CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: SQL statement "LET var1.a = var1.a + 10"
-PL/pgSQL function inline_code_block line 1 at SQL statement
+CONTEXT: PL/pgSQL function inline_code_block line 1 at LET
SET ROLE TO DEFAULT;
GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
SET ROLE TO regress_var_test_role;
@@ -1174,8 +1173,7 @@ ERROR: permission denied for session variable var1
CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: SQL statement "LET var1.a = var1.a + 10"
-PL/pgSQL function inline_code_block line 1 at SQL statement
+CONTEXT: PL/pgSQL function inline_code_block line 1 at LET
SET ROLE TO DEFAULT;
DROP VARIABLE var1;
DROP TABLE vartesttab;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index a2147df28b3..d559087c68f 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1898,6 +1898,7 @@ PLpgSQL_stmt_forq
PLpgSQL_stmt_fors
PLpgSQL_stmt_getdiag
PLpgSQL_stmt_if
+PLpgSQL_stmt_let
PLpgSQL_stmt_loop
PLpgSQL_stmt_open
PLpgSQL_stmt_perform
--
2.48.1
[text/x-patch] v20250212-0017-allow-parallel-execution-queries-with-session-variab.patch (15.8K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/8-v20250212-0017-allow-parallel-execution-queries-with-session-variab.patch)
download | inline diff:
From 270f2eb9db22880ceb22e5bda138f098bf98d54a Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:08:17 +0100
Subject: [PATCH 17/22] allow parallel execution queries with session variables
---
doc/src/sgml/parallel.sgml | 6 -
src/backend/commands/session_variable.c | 23 +++
src/backend/executor/execMain.c | 20 ++-
src/backend/executor/execParallel.c | 147 +++++++++++++++++-
src/backend/optimizer/util/clauses.c | 18 +--
src/backend/tcop/pquery.c | 3 +
src/include/commands/session_variable.h | 1 +
src/include/executor/execdesc.h | 4 +
src/include/nodes/execnodes.h | 1 +
.../regress/expected/session_variables.out | 12 +-
10 files changed, 206 insertions(+), 29 deletions(-)
diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index 683dede6adc..1ce9abf86f5 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -515,12 +515,6 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
Plan nodes that reference a correlated <literal>SubPlan</literal>.
</para>
</listitem>
-
- <listitem>
- <para>
- Plan nodes that use a session variable.
- </para>
- </listitem>
</itemizedlist>
<sect2 id="parallel-labeling">
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 5d907eff60a..367751ed344 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -991,6 +991,29 @@ GetSessionVariable(Oid varid, bool *isNull)
return copy_session_variable_value(svar, isNull);
}
+/*
+ * Returns a copy of the value of the session variable (in the current memory
+ * context) plus typid of the session variable. The caller is responsible for
+ * permission checks.
+ */
+Datum
+GetSessionVariableWithTypeid(Oid varid, bool *isNull, Oid *typid)
+{
+ SVariable svar;
+
+ svar = get_session_variable(varid);
+
+ *typid = svar->typid;
+
+ /*
+ * Although "svar" is freshly validated in this point, svar->is_valid can
+ * be false, if an invalidation message was processed during the domain check.
+ * But the variable and all its dependencies are locked now, so we don't need
+ * to repeat the validation.
+ */
+ return copy_session_variable_value(svar, isNull);
+}
+
/*
* Assign the result of the evaluated expression to the session variable
*/
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index e51df01c393..8305ab04c63 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -211,7 +211,19 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
* be changed inside query execution time, and then a reference to
* previously returned value can be corrupted).
*/
- if (queryDesc->plannedstmt->sessionVariables)
+ if (queryDesc->num_session_variables > 0)
+ {
+ /*
+ * When a parallel query needs to access query parameters (including
+ * related session variables), then related session variables are
+ * restored (deserialized) in queryDesc already. So just push pointer
+ * of this array to executor's estate.
+ */
+ Assert(IsParallelWorker());
+ estate->es_session_variables = queryDesc->session_variables;
+ estate->es_num_session_variables = queryDesc->num_session_variables;
+ }
+ else if (queryDesc->plannedstmt->sessionVariables)
{
int nSessionVariables;
int i = 0;
@@ -250,9 +262,9 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
get_session_variable_name(varid));
}
- estate->es_session_variables[i].value =
- GetSessionVariable(varid,
- &estate->es_session_variables[i].isnull);
+ estate->es_session_variables[i].value = GetSessionVariableWithTypeid(varid,
+ &estate->es_session_variables[i].isnull,
+ &estate->es_session_variables[i].typid);
i++;
}
diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c
index 134ff62f5cb..dddc3bba0a0 100644
--- a/src/backend/executor/execParallel.c
+++ b/src/backend/executor/execParallel.c
@@ -12,8 +12,9 @@
* workers and ensuring that their state generally matches that of the
* leader; see src/backend/access/transam/README.parallel for details.
* However, we must save and restore relevant executor state, such as
- * any ParamListInfo associated with the query, buffer/WAL usage info, and
- * the actual plan to be passed down to the worker.
+ * any ParamListInfo associated with the query, buffer/WAL usage info,
+ * session variables buffer, and the actual plan to be passed down to
+ * the worker.
*
* IDENTIFICATION
* src/backend/executor/execParallel.c
@@ -64,6 +65,7 @@
#define PARALLEL_KEY_QUERY_TEXT UINT64CONST(0xE000000000000008)
#define PARALLEL_KEY_JIT_INSTRUMENTATION UINT64CONST(0xE000000000000009)
#define PARALLEL_KEY_WAL_USAGE UINT64CONST(0xE00000000000000A)
+#define PARALLEL_KEY_SESSION_VARIABLES UINT64CONST(0xE00000000000000B)
#define PARALLEL_TUPLE_QUEUE_SIZE 65536
@@ -138,6 +140,12 @@ static bool ExecParallelRetrieveInstrumentation(PlanState *planstate,
/* Helper function that runs in the parallel worker. */
static DestReceiver *ExecParallelGetReceiver(dsm_segment *seg, shm_toc *toc);
+/* Helper functions that can pass values of session variables */
+static Size EstimateSessionVariables(EState *estate);
+static void SerializeSessionVariables(EState *estate, char **start_address);
+static SessionVariableValue *RestoreSessionVariables(char **start_address,
+ int *num_session_variables);
+
/*
* Create a serialized representation of the plan to be sent to each worker.
*/
@@ -598,6 +606,7 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
char *pstmt_data;
char *pstmt_space;
char *paramlistinfo_space;
+ char *session_variables_space;
BufferUsage *bufusage_space;
WalUsage *walusage_space;
SharedExecutorInstrumentation *instrumentation = NULL;
@@ -607,6 +616,7 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
int instrumentation_len = 0;
int jit_instrumentation_len = 0;
int instrument_offset = 0;
+ int session_variables_len = 0;
Size dsa_minsize = dsa_minimum_size();
char *query_string;
int query_len;
@@ -662,6 +672,11 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
shm_toc_estimate_chunk(&pcxt->estimator, paramlistinfo_len);
shm_toc_estimate_keys(&pcxt->estimator, 1);
+ /* Estimate space for serialized session variables. */
+ session_variables_len = EstimateSessionVariables(estate);
+ shm_toc_estimate_chunk(&pcxt->estimator, session_variables_len);
+ shm_toc_estimate_keys(&pcxt->estimator, 1);
+
/*
* Estimate space for BufferUsage.
*
@@ -763,6 +778,11 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
shm_toc_insert(pcxt->toc, PARALLEL_KEY_PARAMLISTINFO, paramlistinfo_space);
SerializeParamList(estate->es_param_list_info, ¶mlistinfo_space);
+ /* Store serialized session variables. */
+ session_variables_space = shm_toc_allocate(pcxt->toc, session_variables_len);
+ shm_toc_insert(pcxt->toc, PARALLEL_KEY_SESSION_VARIABLES, session_variables_space);
+ SerializeSessionVariables(estate, &session_variables_space);
+
/* Allocate space for each worker's BufferUsage; no need to initialize. */
bufusage_space = shm_toc_allocate(pcxt->toc,
mul_size(sizeof(BufferUsage), pcxt->nworkers));
@@ -1413,6 +1433,7 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
SharedJitInstrumentation *jit_instrumentation;
int instrument_options = 0;
void *area_space;
+ char *sessionvariable_space;
dsa_area *area;
ParallelWorkerContext pwcxt;
@@ -1438,6 +1459,14 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
area_space = shm_toc_lookup(toc, PARALLEL_KEY_DSA, false);
area = dsa_attach_in_place(area_space, seg);
+ /* Reconstruct session variables. */
+ sessionvariable_space = shm_toc_lookup(toc,
+ PARALLEL_KEY_SESSION_VARIABLES,
+ false);
+ queryDesc->session_variables =
+ RestoreSessionVariables(&sessionvariable_space,
+ &queryDesc->num_session_variables);
+
/* Start up the executor */
queryDesc->plannedstmt->jitFlags = fpes->jit_flags;
ExecutorStart(queryDesc, fpes->eflags);
@@ -1505,3 +1534,117 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
FreeQueryDesc(queryDesc);
receiver->rDestroy(receiver);
}
+
+/*
+ * Estimate the amount of space required to serialize a session variable.
+ */
+static Size
+EstimateSessionVariables(EState *estate)
+{
+ int i;
+ Size sz = sizeof(int);
+
+ if (estate->es_session_variables == NULL)
+ return sz;
+
+ for (i = 0; i < estate->es_num_session_variables; i++)
+ {
+ SessionVariableValue *svarval;
+ Oid typeOid;
+ int16 typLen;
+ bool typByVal;
+
+ svarval = &estate->es_session_variables[i];
+
+ typeOid = svarval->typid;
+
+ sz = add_size(sz, sizeof(Oid)); /* space for type OID */
+
+ /* space for datum/isnull */
+ Assert(OidIsValid(typeOid));
+ get_typlenbyval(typeOid, &typLen, &typByVal);
+
+ sz = add_size(sz,
+ datumEstimateSpace(svarval->value, svarval->isnull, typByVal, typLen));
+ }
+
+ return sz;
+}
+
+/*
+ * Serialize a session variables buffer into caller-provided storage.
+ *
+ * We write the number of parameters first, as a 4-byte integer, and then
+ * write details for each parameter in turn. The details for each parameter
+ * consist of a 4-byte type OID, and then the datum as serialized by
+ * datumSerialize(). The caller is responsible for ensuring that there is
+ * enough storage to store the number of bytes that will be written; use
+ * EstimateSessionVariables to find out how many will be needed.
+ * *start_address is updated to point to the byte immediately following those
+ * written.
+ *
+ * RestoreSessionVariables can be used to recreate a session variable buffer
+ * based on the serialized representation;
+ */
+static void
+SerializeSessionVariables(EState *estate, char **start_address)
+{
+ int nparams;
+ int i;
+
+ /* Write number of parameters. */
+ nparams = estate->es_num_session_variables;
+ memcpy(*start_address, &nparams, sizeof(int));
+ *start_address += sizeof(int);
+
+ /* Write each parameter in turn. */
+ for (i = 0; i < nparams; i++)
+ {
+ SessionVariableValue *svarval;
+ Oid typeOid;
+ int16 typLen;
+ bool typByVal;
+
+ svarval = &estate->es_session_variables[i];
+ typeOid = svarval->typid;
+
+ /* Write type OID. */
+ memcpy(*start_address, &typeOid, sizeof(Oid));
+ *start_address += sizeof(Oid);
+
+ Assert(OidIsValid(typeOid));
+ get_typlenbyval(typeOid, &typLen, &typByVal);
+
+ datumSerialize(svarval->value, svarval->isnull, typByVal, typLen,
+ start_address);
+ }
+}
+
+static SessionVariableValue *
+RestoreSessionVariables(char **start_address, int *num_session_variables)
+{
+ SessionVariableValue *session_variables;
+ int i;
+ int nparams;
+
+ memcpy(&nparams, *start_address, sizeof(int));
+ *start_address += sizeof(int);
+
+ *num_session_variables = nparams;
+ session_variables = (SessionVariableValue *)
+ palloc(nparams * sizeof(SessionVariableValue));
+
+ for (i = 0; i < nparams; i++)
+ {
+ SessionVariableValue *svarval = &session_variables[i];
+
+ /* Read type OID. */
+ memcpy(&svarval->typid, *start_address, sizeof(Oid));
+ *start_address += sizeof(Oid);
+
+ /* Read datum/isnull. */
+ svarval->value = datumRestore(start_address, &svarval->isnull);
+ }
+
+ return session_variables;
+}
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index f60828f862e..175390c6c28 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -923,25 +923,19 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
/*
* We can't pass Params to workers at the moment either, so they are also
- * parallel-restricted, unless they are PARAM_EXTERN Params or are
- * PARAM_EXEC Params listed in safe_param_ids, meaning they could be
- * either generated within workers or can be computed by the leader and
- * then their value can be passed to workers.
+ * parallel-restricted, unless they are PARAM_EXTERN or PARAM_VARIABLE
+ * Params or are PARAM_EXEC Params listed in safe_param_ids, meaning they
+ * could be either generated within workers or can be computed by the
+ * leader and then their value can be passed to workers.
*/
else if (IsA(node, Param))
{
Param *param = (Param *) node;
- if (param->paramkind == PARAM_EXTERN)
+ if (param->paramkind == PARAM_EXTERN ||
+ param->paramkind == PARAM_VARIABLE)
return false;
- /* we don't support passing session variables to workers */
- if (param->paramkind == PARAM_VARIABLE)
- {
- if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
- return true;
- }
-
if (param->paramkind != PARAM_EXEC ||
!list_member_int(context->safe_param_ids, param->paramid))
{
diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c
index 6f22496305a..6f9bd7c8b05 100644
--- a/src/backend/tcop/pquery.c
+++ b/src/backend/tcop/pquery.c
@@ -86,6 +86,9 @@ CreateQueryDesc(PlannedStmt *plannedstmt,
qd->queryEnv = queryEnv;
qd->instrument_options = instrument_options; /* instrumentation wanted? */
+ qd->num_session_variables = 0;
+ qd->session_variables = NULL;
+
/* null these fields until set by ExecutorStart */
qd->tupDesc = NULL;
qd->estate = NULL;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index 4492bee6d69..f66b6c0b864 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -29,6 +29,7 @@ extern void AtEOSubXact_SessionVariables(bool isCommit, SubTransactionId mySubid
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
+extern Datum GetSessionVariableWithTypeid(Oid varid, bool *isNull, Oid *typid);
extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
QueryEnvironment *queryEnv, QueryCompletion *qc);
diff --git a/src/include/executor/execdesc.h b/src/include/executor/execdesc.h
index 86db3dc8d0d..4e0fa3ea40f 100644
--- a/src/include/executor/execdesc.h
+++ b/src/include/executor/execdesc.h
@@ -51,6 +51,10 @@ typedef struct QueryDesc
/* This field is set by ExecutePlan */
bool already_executed; /* true if previously executed */
+ /* reference to session variables buffer */
+ int num_session_variables;
+ SessionVariableValue *session_variables;
+
/* This is always set NULL by the core system, but plugins can change it */
struct Instrumentation *totaltime; /* total time spent in ExecutorRun */
} QueryDesc;
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 91051681d3b..c143b6419ed 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -641,6 +641,7 @@ typedef struct AsyncRequest
*/
typedef struct SessionVariableValue
{
+ Oid typid;
bool isnull;
Datum value;
} SessionVariableValue;
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 0a410d6ab00..3ee20b2643d 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1284,12 +1284,14 @@ SELECT count(*) FROM svar_test WHERE a%10 = zero;
-- parallel execution is not supported yet
EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
- QUERY PLAN
------------------------------------
+ QUERY PLAN
+--------------------------------------------
Aggregate
- -> Seq Scan on svar_test
- Filter: ((a % 10) = zero)
-(3 rows)
+ -> Gather
+ Workers Planned: 2
+ -> Parallel Seq Scan on svar_test
+ Filter: ((a % 10) = zero)
+(5 rows)
LET zero = (SELECT count(*) FROM svar_test);
-- result should be 1000
--
2.48.1
[text/x-patch] v20250212-0016-allow-read-an-value-of-session-variable-directly-fro.patch (15.1K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/9-v20250212-0016-allow-read-an-value-of-session-variable-directly-fro.patch)
download | inline diff:
From d3bb367d543624ccaf65edb6e8fd98b0497cc7a4 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:07:03 +0100
Subject: [PATCH 16/22] allow read an value of session variable directly from
expression executor
The expression executor can be called directly (not inside query executor)
when expression is evaluated as simple expression in plpgsql or when expression
is an argument of CALL or EXECUTE statements. For these cases we need to allow direct
access to content of session variables from executor. We can do it, because
we know so the expression is not evaluated under query and cannot be
evaluated inside parallel worker.
This patch enables session variables for simple expression evaluation.
This patch enables usage session variables in arguments of CALL stmt.
---
src/backend/commands/prepare.c | 10 ---
src/backend/executor/execExpr.c | 86 +++++++++++++++----
src/backend/executor/execExprInterp.c | 14 +++
src/backend/jit/llvm/llvmjit_expr.c | 6 ++
src/backend/parser/analyze.c | 10 ---
src/include/executor/execExpr.h | 11 ++-
.../src/expected/plpgsql_session_variable.out | 3 +-
src/pl/plpgsql/src/pl_exec.c | 3 +-
.../regress/expected/session_variables.out | 38 ++++----
src/test/regress/sql/session_variables.sql | 12 +--
10 files changed, 125 insertions(+), 68 deletions(-)
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 4ea2bfea4ea..70f03099996 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -338,16 +338,6 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
i++;
}
- /*
- * The arguments of EXECUTE are evaluated by a direct expression
- * executor call. This mode doesn't support session variables yet.
- * It will be enabled later.
- */
- if (pstate->p_hasSessionVariables)
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("session variable cannot be used as an argument")));
-
/* Prepare the expressions for execution */
exprstates = ExecPrepareExprList(params, estate);
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 270e6d344be..d07377948a0 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -34,6 +34,8 @@
#include "catalog/objectaccess.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
#include "executor/execExpr.h"
#include "executor/nodeSubplan.h"
#include "funcapi.h"
@@ -1054,22 +1056,74 @@ ExecInitExprRec(Expr *node, ExprState *state,
es_num_session_variables = state->parent->state->es_num_session_variables;
}
- Assert(es_session_variables);
-
- /* parameter sanity checks */
- if (param->paramid >= es_num_session_variables)
- elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
-
- var = &es_session_variables[param->paramid];
-
- /*
- * In this case, pass the value like a
- * constant.
- */
- scratch.opcode = EEOP_CONST;
- scratch.d.constval.value = var->value;
- scratch.d.constval.isnull = var->isnull;
- ExprEvalPushStep(state, &scratch);
+ if (es_session_variables)
+ {
+ /*
+ * This path is used when expression is
+ * evaluated inside query evaluation. For
+ * ensuring of immutability of session variable
+ * inside query we use special buffer with copy
+ * of used session variables. This method helps
+ * with parallel execution too.
+ */
+
+ /* parameter sanity checks */
+ if (param->paramid >= es_num_session_variables)
+ elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
+
+ var = &es_session_variables[param->paramid];
+
+ /*
+ * In this case, pass the value like a
+ * constant.
+ */
+ scratch.opcode = EEOP_CONST;
+ scratch.d.constval.value = var->value;
+ scratch.d.constval.isnull = var->isnull;
+ ExprEvalPushStep(state, &scratch);
+ }
+ else
+ {
+ Oid varid = param->paramvarid;
+
+ Assert(!IsParallelWorker());
+
+ /*
+ * In some cases (plpgsql's simple expression
+ * evaluation or evaluation of CALL arguments),
+ * the expression executor is called directly.
+ * We can allow direct access to session
+ * variables (copy only), because we know, so
+ * outside is not any query (and expression
+ * cannot be executed parallel).
+ *
+ * In this case we should to do aclcheck,
+ * because usual aclcheck from
+ * standard_ExecutorStart is not executed in
+ * this case. Fortunately it is just once per
+ * transaction.
+ *
+ * Don't do permission check, when variable is
+ * used like base node for assignment indirection.
+ */
+ if (!param->parambasenode)
+ {
+ AclResult aclresult;
+
+ aclresult = object_aclcheck(
+ VariableRelationId, varid,
+ GetUserId(), ACL_SELECT);
+
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult,
+ OBJECT_VARIABLE,
+ get_session_variable_name(varid));
+ }
+
+ scratch.opcode = EEOP_PARAM_VARIABLE;
+ scratch.d.vparam.varid = varid;
+ ExprEvalPushStep(state, &scratch);
+ }
}
break;
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 1c3477b03c9..45ec7b58610 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -59,6 +59,7 @@
#include "access/heaptoast.h"
#include "catalog/pg_type.h"
#include "commands/sequence.h"
+#include "commands/session_variable.h"
#include "executor/execExpr.h"
#include "executor/nodeSubplan.h"
#include "funcapi.h"
@@ -521,6 +522,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
&&CASE_EEOP_PARAM_EXEC,
&&CASE_EEOP_PARAM_EXTERN,
&&CASE_EEOP_PARAM_CALLBACK,
+ &&CASE_EEOP_PARAM_VARIABLE,
&&CASE_EEOP_PARAM_SET,
&&CASE_EEOP_CASE_TESTVAL,
&&CASE_EEOP_CASE_TESTVAL_EXT,
@@ -1265,6 +1267,18 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
EEO_NEXT();
}
+ EEO_CASE(EEOP_PARAM_VARIABLE)
+ {
+ /*
+ * Direct access to session variable (without buffering). Because
+ * returned value can be used (without an assignement) after the
+ * referenced session variables is updated, we have to use an copy
+ * of stored value every time.
+ */
+ *op->resvalue = GetSessionVariable(op->d.vparam.varid, op->resnull);
+ EEO_NEXT();
+ }
+
EEO_CASE(EEOP_PARAM_SET)
{
/* out of line, unlikely to matter performance-wise */
diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c
index f0f5c3bd49f..ad8d80cf49c 100644
--- a/src/backend/jit/llvm/llvmjit_expr.c
+++ b/src/backend/jit/llvm/llvmjit_expr.c
@@ -1208,6 +1208,12 @@ llvm_compile_expr(ExprState *state)
break;
}
+ case EEOP_PARAM_VARIABLE:
+ build_EvalXFunc(b, mod, "ExecEvalParamVariable",
+ v_state, op, v_econtext);
+ LLVMBuildBr(b, opblocks[opno + 1]);
+ break;
+
case EEOP_PARAM_SET:
build_EvalXFunc(b, mod, "ExecEvalParamSet",
v_state, op, v_econtext);
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index c0c3abd7a0e..46a22ff5c94 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -3571,16 +3571,6 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt)
true,
stmt->funccall->location);
- /*
- * The arguments of CALL statement are evaluated by a direct expression
- * executor call. This path is unsupported yet, so block it. It will be
- * enabled later.
- */
- if (pstate->p_hasSessionVariables)
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("session variable cannot be used as an argument")));
-
assign_expr_collations(pstate, node);
fexpr = castNode(FuncExpr, node);
diff --git a/src/include/executor/execExpr.h b/src/include/executor/execExpr.h
index 191d8fe34de..1259ef72bac 100644
--- a/src/include/executor/execExpr.h
+++ b/src/include/executor/execExpr.h
@@ -164,10 +164,11 @@ typedef enum ExprEvalOp
EEOP_BOOLTEST_IS_FALSE,
EEOP_BOOLTEST_IS_NOT_FALSE,
- /* evaluate PARAM_EXEC/EXTERN parameters */
+ /* evaluate PARAM_EXEC/EXTERN/VARIABLE parameters */
EEOP_PARAM_EXEC,
EEOP_PARAM_EXTERN,
EEOP_PARAM_CALLBACK,
+ EEOP_PARAM_VARIABLE,
/* set PARAM_EXEC value */
EEOP_PARAM_SET,
@@ -430,6 +431,12 @@ typedef struct ExprEvalStep
Oid paramtype; /* OID of parameter's datatype */
} cparam;
+ /* for EEOP_PARAM_VARIABLE */
+ struct
+ {
+ Oid varid; /* OID of assigned variable */
+ } vparam;
+
/* for EEOP_CASE_TESTVAL/DOMAIN_TESTVAL */
struct
{
@@ -852,6 +859,8 @@ extern void ExecEvalParamSet(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalParamExtern(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
+extern void ExecEvalParamVariable(ExprState *state, ExprEvalStep *op,
+ ExprContext *econtext);
extern void ExecEvalCoerceViaIOSafe(ExprState *state, ExprEvalStep *op);
extern void ExecEvalSQLValueFunction(ExprState *state, ExprEvalStep *op);
extern void ExecEvalCurrentOfExpr(ExprState *state, ExprEvalStep *op);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index a6523f7afe2..ecac64fcfb4 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -211,8 +211,7 @@ SET ROLE TO regress_var_exec_role;
-- should fail
SELECT var_read_func();
ERROR: permission denied for session variable plpgsql_sv_var1
-CONTEXT: PL/pgSQL expression "plpgsql_sv_var1"
-PL/pgSQL function var_read_func() line 3 at RAISE
+CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE
SET ROLE TO DEFAULT;
SET ROLE TO regress_var_owner_role;
GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index cb282404c1a..d4377ceecbf 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8264,8 +8264,7 @@ exec_is_simple_query(PLpgSQL_expr *expr)
query->sortClause ||
query->limitOffset ||
query->limitCount ||
- query->setOperations ||
- query->hasSessionVariables)
+ query->setOperations)
return false;
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index ed538071602..0a410d6ab00 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -483,8 +483,7 @@ ERROR: permission denied for session variable var1
CONTEXT: SQL function "sqlfx" statement 1
SELECT plpgsqlfx(20);
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "$1 + var1"
-PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
+CONTEXT: PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
-- should be ok
SELECT sqlfx_sd(20);
sqlfx_sd
@@ -780,27 +779,28 @@ $$;
NOTICE: result array: {1,2,3,4,5,6,7,8,9,10}
DROP VARIABLE var1;
DROP VARIABLE var2;
--- CALL statement is not supported yet
--- requires direct access to session variable from expression executor
+-- CALL statement is supported
CREATE VARIABLE v int;
+LET v = 1;
CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
--- should not crash (but is not supported yet)
+-- should to work
CALL p(v);
-ERROR: session variable cannot be used as an argument
+NOTICE: 1
DO $$ BEGIN CALL p(v); END $$;
-ERROR: session variable cannot be used as an argument
-CONTEXT: SQL statement "CALL p(v)"
-PL/pgSQL function inline_code_block line 1 at CALL
+NOTICE: 1
DROP PROCEDURE p(int);
DROP VARIABLE v;
--- EXECUTE statement is not supported yet
--- requires direct access to session variable from expression executor
+-- EXECUTE statement
CREATE VARIABLE v int;
LET v = 20;
PREPARE ptest(int) AS SELECT $1;
--- should fail
+-- should be ok
EXECUTE ptest(v);
-ERROR: session variable cannot be used as an argument
+ ?column?
+----------
+ 20
+(1 row)
+
DEALLOCATE ptest;
DROP VARIABLE v;
-- test search path
@@ -1123,12 +1123,10 @@ LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a
ERROR: permission denied for session variable var1
DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1.a"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
CONTEXT: SQL statement "LET var1.a = var1.a + 10"
@@ -1170,12 +1168,10 @@ LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a
ERROR: permission denied for session variable var1
DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1.a"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
CONTEXT: SQL statement "LET var1.a = var1.a + 10"
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index b83e905284e..a54665dd10b 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -548,13 +548,14 @@ $$;
DROP VARIABLE var1;
DROP VARIABLE var2;
--- CALL statement is not supported yet
--- requires direct access to session variable from expression executor
+-- CALL statement is supported
CREATE VARIABLE v int;
+LET v = 1;
+
CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
--- should not crash (but is not supported yet)
+-- should to work
CALL p(v);
DO $$ BEGIN CALL p(v); END $$;
@@ -562,13 +563,12 @@ DO $$ BEGIN CALL p(v); END $$;
DROP PROCEDURE p(int);
DROP VARIABLE v;
--- EXECUTE statement is not supported yet
--- requires direct access to session variable from expression executor
+-- EXECUTE statement
CREATE VARIABLE v int;
LET v = 20;
PREPARE ptest(int) AS SELECT $1;
--- should fail
+-- should be ok
EXECUTE ptest(v);
DEALLOCATE ptest;
--
2.48.1
[text/x-patch] v20250212-0015-Implementation-of-NOT-NULL-and-IMMUTABLE-clauses.patch (33.9K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/10-v20250212-0015-Implementation-of-NOT-NULL-and-IMMUTABLE-clauses.patch)
download | inline diff:
From 00611be2c58bc45acede0ba09864ce063a55685e Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:05:06 +0100
Subject: [PATCH 15/22] Implementation of NOT NULL and IMMUTABLE clauses
Almost trivial patch - psql, pg_dump support
---
doc/src/sgml/catalogs.sgml | 20 +++
doc/src/sgml/plpgsql.sgml | 3 +-
doc/src/sgml/ref/create_variable.sgml | 32 +++-
src/backend/catalog/pg_variable.c | 8 +
src/backend/commands/session_variable.c | 69 ++++++++-
src/backend/parser/gram.y | 41 +++--
src/bin/pg_dump/pg_dump.c | 19 ++-
src/bin/pg_dump/pg_dump.h | 2 +
src/bin/pg_dump/t/002_pg_dump.pl | 36 +++++
src/bin/psql/describe.c | 6 +-
src/bin/psql/tab-complete.in.c | 12 +-
src/include/catalog/pg_variable.h | 6 +
src/include/nodes/parsenodes.h | 2 +
src/test/regress/expected/psql.out | 36 ++---
.../regress/expected/session_variables.out | 145 ++++++++++++++++++
src/test/regress/sql/session_variables.sql | 122 +++++++++++++++
16 files changed, 518 insertions(+), 41 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 27bdaf62668..c7a8170ddf2 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9867,6 +9867,26 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
<row>
<entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varnotnull</structfield> <type>boolean</type>
+ </para>
+ <para>
+ True if the session variable doesn't allow null values. The default value is false.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varisimmutable</structfield> <type>boolean</type>
+ </para>
+ <para>
+ True if the variable is <link linkend="sql-createvariable-immutable">immutable</link> (cannot be modified).
+ The default value is false.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vareoxaction</structfield> <type>char</type>
<structfield>varxactendaction</structfield> <type>char</type>
</para>
<para>
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index bfbff9ab74e..e704e05a991 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -6044,7 +6044,8 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE;
You can consider translating an Oracle package into a schema in
<productname>PostgreSQL</productname>. Package functions and procedures
would then become functions and procedures in that schema, and package
- variables could be translated to session variables in that schema.
+ variables could be translated to session variables or immutable session
+ variables in that schema.
(see <xref linkend="ddl-session-variables"/>).
</para>
</sect3>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index e4d8851ccb8..3c3e6d55b69 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -26,8 +26,8 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
- [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
+CREATE [ { TEMPORARY | TEMP } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+ [ NOT NULL ] [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -65,6 +65,22 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
<variablelist>
+ <varlistentry id="sql-createvariable-immutable">
+ <term><literal>IMMUTABLE</literal></term>
+ <listitem>
+ <para>
+ The assigned value of the session variable can not be changed.
+ Only if the session variable doesn't have a default value, a single
+ initialization is allowed using the <command>LET</command> command. Once
+ done, no further change is allowed until end of transaction
+ if the session variable was created with clause <literal>ON TRANSACTION
+ END RESET</literal>, or until reset of all session variables by
+ <command>DISCARD VARIABLES</command>, or until reset of all session
+ objects by command <command>DISCARD ALL</command>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createvariable-if-not-exists">
<term><literal>IF NOT EXISTS</literal></term>
<listitem>
@@ -105,6 +121,18 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-not-null">
+ <term><literal>NOT NULL</literal></term>
+ <listitem>
+ <para>
+ The <literal>NOT NULL</literal> clause forbids setting the session
+ variable to a null value. A session variable created as NOT NULL
+ should not to have a declared default value, and if the variable
+ has not assigned value, then the reading of this variable fails.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createvariable-default">
<term><literal>DEFAULT <replaceable>default_expr</replaceable></literal></term>
<listitem>
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 8fba4cc493b..0b6093a00ba 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -40,6 +40,8 @@ static ObjectAddress create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ bool not_null,
+ bool is_immutable,
Node *varDefexpr,
VariableXactEndAction varXactEndAction);
@@ -55,6 +57,8 @@ create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ bool not_null,
+ bool is_immutable,
Node *varDefexpr,
VariableXactEndAction varXactEndAction)
{
@@ -117,6 +121,8 @@ create_variable(const char *varName,
values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+ values[Anum_pg_variable_varnotnull - 1] = BoolGetDatum(not_null);
+ values[Anum_pg_variable_varisimmutable - 1] = BoolGetDatum(is_immutable);
values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
if (varDefexpr)
@@ -259,6 +265,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
varowner,
collation,
stmt->if_not_exists,
+ stmt->not_null,
+ stmt->is_immutable,
cooked_default,
stmt->XactEndAction);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 40275abfa7e..5d907eff60a 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -84,6 +84,9 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ bool not_null;
+ bool is_immutable;
+
bool reset_at_eox;
/*
@@ -102,6 +105,9 @@ typedef struct SVariableData
bool is_valid;
uint32 hashvalue; /* used for pairing sinval message */
+
+ /* true, when the value is already set, and cannot be changed more */
+ bool protect_value;
} SVariableData;
typedef SVariableData *SVariable;
@@ -563,6 +569,23 @@ eval_assign_defexpr(SVariable svar, HeapTuple tup)
MemoryContextSwitchTo(oldcxt);
}
+ else
+ {
+ /*
+ * Raise an error if this is a NOT NULL variable but the result of
+ * DEFAULT expression is NULL.
+ */
+ if (svar->not_null)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("null value is not allowed for NOT NULL session variable \"%s.%s\"",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid)),
+ errdetail("The result of DEFAULT expression is NULL.")));
+ }
+
+ if (svar->is_immutable)
+ svar->protect_value = true;
FreeExecutorState(estate);
}
@@ -593,6 +616,9 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval);
+ svar->not_null = varform->varnotnull;
+ svar->is_immutable = varform->varisimmutable;
+
svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
@@ -622,9 +648,31 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
ObjectIdGetDatum(varid));
- if (!is_write)
+ svar->protect_value = false;
+
+ /*
+ * When the variable is marked as IMMUTABLE, we prefer to evaluate
+ * possible DEFAULT before write op. In this case we want to protect
+ * default value against any overwrite.
+ */
+ if (!is_write ||
+ svar->is_immutable)
+ {
eval_assign_defexpr(svar, tup);
+ /*
+ * Raise an error if this is a NOT NULL variable without default
+ * expression.
+ */
+ if (svar->isnull && svar->not_null)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("null value is not allowed for NOT NULL session variable \"%s.%s\"",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ errdetail("The session variable was not initialized yet.")));
+ }
+
ReleaseSysCache(tup);
}
@@ -644,6 +692,21 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
Assert(svar);
Assert(!isnull || value == (Datum) 0);
+ if (svar->protect_value)
+ ereport(ERROR,
+ (errcode(ERRCODE_ERROR_IN_ASSIGNMENT),
+ errmsg("session variable \"%s.%s\" is declared IMMUTABLE",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid))));
+
+ /* don't allow assignment of null to NOT NULL variable */
+ if (isnull && svar->not_null)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("null value is not allowed for NOT NULL session variable \"%s.%s\"",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid))));
+
/*
* Use typbyval, typbylen from session variable only when they are
* trustworthy (the invalidation message was not accepted for this
@@ -684,6 +747,10 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
svar->value = newval;
svar->isnull = isnull;
+
+ /* don't allow more changes of value when variable is IMMUTABLE */
+ if (svar->is_immutable)
+ svar->protect_value = true;
}
/*
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 1d10eb7c52c..11ae96a4397 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -675,6 +675,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
json_object_constructor_null_clause_opt
json_array_constructor_null_clause_opt
+%type <boolean> OptNotNull OptImmutable
/*
* Non-keyword token types. These are hard-wired into the "flex" lexer.
@@ -5265,27 +5266,31 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
+ CREATE OptTemp OptImmutable VARIABLE qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $4->relpersistence = $2;
- n->variable = $4;
- n->typeName = $6;
- n->collClause = (CollateClause *) $7;
- n->defexpr = $8;
- n->XactEndAction = $9;
+ $5->relpersistence = $2;
+ n->is_immutable = $3;
+ n->variable = $5;
+ n->typeName = $7;
+ n->collClause = (CollateClause *) $8;
+ n->not_null = $9;
+ n->defexpr = $10;
+ n->XactEndAction = $11;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
+ | CREATE OptTemp OptImmutable VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $7->relpersistence = $2;
- n->variable = $7;
- n->typeName = $9;
- n->collClause = (CollateClause *) $10;
- n->defexpr = $11;
- n->XactEndAction = $12;
+ $8->relpersistence = $2;
+ n->is_immutable = $3;
+ n->variable = $8;
+ n->typeName = $10;
+ n->collClause = (CollateClause *) $11;
+ n->not_null = $12;
+ n->defexpr = $13;
+ n->XactEndAction = $14;
n->if_not_exists = true;
$$ = (Node *) n;
}
@@ -5305,6 +5310,14 @@ XactEndActionOption: ON COMMIT DROP { $$ = VARIABLE_XACTEND_DROP; }
;
+OptNotNull: NOT NULL_P { $$ = true; }
+ | /* EMPTY */ { $$ = false; }
+ ;
+
+OptImmutable: IMMUTABLE { $$ = true; }
+ | /* EMPTY */ { $$ = false; }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 7ed6fa5ac4b..727f6a18f25 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5442,6 +5442,8 @@ getVariables(Archive *fout)
int i_varxactendaction;
int i_varowner;
int i_varcollation;
+ int i_varnotnull;
+ int i_varisimmutable;
int i_varacl;
int i_acldefault;
int i,
@@ -5462,6 +5464,8 @@ getVariables(Archive *fout)
" THEN v.varcollation\n"
" ELSE 0\n"
" END AS varcollation,\n"
+ " v.varnotnull,\n"
+ " v.varisimmutable,\n"
" pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n"
" v.varowner, v.varacl,\n"
" acldefault('V', v.varowner) AS acldefault\n"
@@ -5482,6 +5486,8 @@ getVariables(Archive *fout)
i_vardefexpr = PQfnumber(res, "vardefexpr");
i_varxactendaction = PQfnumber(res, "varxactendaction");
i_varcollation = PQfnumber(res, "varcollation");
+ i_varnotnull = PQfnumber(res, "varnotnull");
+ i_varisimmutable = PQfnumber(res, "varisimmutable");
i_varowner = PQfnumber(res, "varowner");
i_varacl = PQfnumber(res, "varacl");
@@ -5508,6 +5514,8 @@ getVariables(Archive *fout)
pg_strdup(PQgetvalue(res, i, i_varxactendaction));
varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
+ varinfo[i].varnotnull = *(PQgetvalue(res, i, i_varnotnull)) == 't';
+ varinfo[i].varisimmutable = *(PQgetvalue(res, i, i_varisimmutable)) == 't';
varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
@@ -5554,7 +5562,9 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
const char *vartypname;
const char *vardefexpr;
const char *varxactendaction;
+ const char *varisimmutable;
Oid varcollation;
+ bool varnotnull;
/* skip if not to be dumped */
if (!varinfo->dobj.dump || !dopt->dumpSchema)
@@ -5568,12 +5578,14 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
vardefexpr = varinfo->vardefexpr;
varxactendaction = varinfo->varxactendaction;
varcollation = varinfo->varcollation;
+ varnotnull = varinfo->varnotnull;
+ varisimmutable = varinfo->varisimmutable ? "IMMUTABLE " : "";
appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
qualvarname);
- appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s",
- qualvarname, vartypname);
+ appendPQExpBuffer(query, "CREATE %sVARIABLE %s AS %s",
+ varisimmutable, qualvarname, vartypname);
if (OidIsValid(varcollation))
{
@@ -5585,6 +5597,9 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
fmtQualifiedDumpable(coll));
}
+ if (varnotnull)
+ appendPQExpBuffer(query, " NOT NULL");
+
if (vardefexpr)
appendPQExpBuffer(query, " DEFAULT %s",
vardefexpr);
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index ef1ba042132..0ae406f8551 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -722,6 +722,8 @@ typedef struct _VariableInfo
char *varxactendaction;
Oid varcollation;
const char *rolname; /* name of owner, or empty string */
+ bool varnotnull;
+ bool varisimmutable;
} VariableInfo;
/*
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index fb25f80a852..5f80bd4e79a 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4108,6 +4108,42 @@ my %tests = (
},
},
+ 'CREATE IMMUTABLE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE IMMUTABLE VARIABLE dump_test.variable5 AS integer',
+ regexp => qr/^
+ \QCREATE IMMUTABLE VARIABLE dump_test.variable5 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
+ 'CREATE IMMUTABLE VARIABLE test_variable NOT NULL DEFAULT' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE IMMUTABLE VARIABLE dump_test.variable7 AS integer NOT NULL DEFAULT 10',
+ regexp => qr/^
+ \QCREATE IMMUTABLE VARIABLE dump_test.variable7 AS integer NOT NULL DEFAULT 10;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index b5e5d073f9c..07835aa2bab 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5352,6 +5352,8 @@ listVariables(const char *pattern, bool verbose)
" (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
" WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
+ " NOT v.varnotnull as \"%s\",\n"
+ " NOT v.varisimmutable as \"%s\",\n"
" pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
@@ -5362,6 +5364,8 @@ listVariables(const char *pattern, bool verbose)
gettext_noop("Type"),
gettext_noop("Collation"),
gettext_noop("Owner"),
+ gettext_noop("Nullable"),
+ gettext_noop("Mutable"),
gettext_noop("Default"),
gettext_noop("Transactional end action"));
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 86c2d5c3a66..f547bce1a10 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1273,6 +1273,8 @@ static const pgsql_thing_t words_after_create[] = {
{"FOREIGN TABLE", NULL, NULL, NULL},
{"FUNCTION", NULL, NULL, Query_for_list_of_functions},
{"GROUP", Query_for_list_of_roles},
+ {"IMMUTABLE VARIABLE", NULL, NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE IMMUTABLE
+ * VARIABLE ... */
{"INDEX", NULL, NULL, &Query_for_list_of_indexes},
{"LANGUAGE", Query_for_list_of_languages},
{"LARGE OBJECT", NULL, NULL, NULL, NULL, THING_NO_CREATE | THING_NO_DROP},
@@ -3612,7 +3614,8 @@ match_previous_words(int pattern_id,
/* CREATE TABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete "CREATE TEMP/TEMPORARY" with the possible temp objects */
else if (TailMatches("CREATE", "TEMP|TEMPORARY"))
- COMPLETE_WITH("SEQUENCE", "TABLE", "VARIABLE", "VIEW");
+ COMPLETE_WITH("IMMUTABLE VARIABLE", "SEQUENCE", "TABLE", "VARIABLE",
+ "VIEW");
/* Complete "CREATE UNLOGGED" with TABLE or SEQUENCE */
else if (TailMatches("CREATE", "UNLOGGED"))
COMPLETE_WITH("TABLE", "SEQUENCE");
@@ -3964,7 +3967,8 @@ match_previous_words(int pattern_id,
/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE VARIABLE <name> with AS */
else if (TailMatches("CREATE", "VARIABLE", MatchAny) ||
- TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny))
+ TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny) ||
+ TailMatches("IMMUTABLE", "VARIABLE", MatchAny))
COMPLETE_WITH("AS");
else if (TailMatches("VARIABLE", MatchAny, "AS"))
/* Complete CREATE VARIABLE <name> with AS types */
@@ -4624,6 +4628,10 @@ match_previous_words(int pattern_id,
else if (TailMatches("FROM", "SERVER", MatchAny, "INTO", MatchAny))
COMPLETE_WITH("OPTIONS (");
+/* IMMUTABLE -- can be expend to IMMUTABLE VARIABLE */
+ else if (TailMatches("CREATE", "IMMUTABLE"))
+ COMPLETE_WITH("VARIABLE");
+
/* INSERT --- can be inside EXPLAIN, RULE, etc */
/* Complete NOT MATCHED THEN INSERT */
else if (TailMatches("NOT", "MATCHED", "THEN", "INSERT"))
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 09dd44a44e1..cf21e0426a7 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -56,6 +56,12 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* typmod for variable's type */
int32 vartypmod BKI_DEFAULT(-1);
+ /* don't allow NULL */
+ bool varnotnull BKI_DEFAULT(f);
+
+ /* don't allow changes */
+ bool varisimmutable BKI_DEFAULT(f);
+
/* action on transaction end */
char varxactendaction BKI_DEFAULT(n);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index d1d2ac91fb5..6bcaf480576 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3535,6 +3535,8 @@ typedef struct CreateSessionVarStmt
TypeName *typeName; /* the type of variable */
CollateClause *collClause;
bool if_not_exists; /* do nothing if it already exists */
+ bool not_null; /* disallow nulls */
+ bool is_immutable; /* don't allow changes */
Node *defexpr; /* default expression */
char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 999fc88d1e1..78aca67e452 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6020,20 +6020,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+---------+--------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | | | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+---------+--------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | | | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6501,9 +6501,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action
---------+------+------+-----------+-------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6676,9 +6676,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action
---------+------+------+-----------+-------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6815,9 +6815,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action
---------+------+------+-----------+-------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index b5adb797801..ed538071602 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2452,3 +2452,148 @@ SELECT var1;
DROP VARIABLE var1;
DROP FUNCTION vartest_fx();
+-- test NOT NULL
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL;
+-- should to fail
+SELECT var1;
+ERROR: null value is not allowed for NOT NULL session variable "public.var1"
+DETAIL: The session variable was not initialized yet.
+--should be ok
+LET var1 = 10;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1;
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT 0;
+--should be ok
+SELECT var1;
+ var1
+------
+ 0
+(1 row)
+
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DISCARD VARIABLES;
+-- should to fail
+LET var1 = NULL;
+ERROR: null value is not allowed for NOT NULL session variable "public.var1"
+DROP VARIABLE var1;
+-- test NOT NULL
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN NULL;
+END;
+$$ LANGUAGE plpgsql;
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT vartest_fx();
+-- should to fail
+SELECT var1;
+ERROR: null value is not allowed for NOT NULL session variable "public.var1"
+DETAIL: The result of DEFAULT expression is NULL.
+DISCARD VARIABLES;
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+DISCARD VARIABLES;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 0
+(1 row)
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
+-- test IMMUTBLE
+CREATE IMMUTABLE VARIABLE var1 AS int;
+-- should be ok
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+-- first write should ok
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DISCARD VARIABLES;
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DISCARD VARIABLES;
+-- should be ok
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+-- should be ok
+LET var1 = NULL;
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DROP VARIABLE var1;
+CREATE IMMUTABLE VARIABLE var1 AS int DEFAULT 10;
+-- don't allow change when variable has DEFAULT value
+-- should to fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DISCARD VARIABLES;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DROP VARIABLE var1;
+-- should be ok
+CREATE IMMUTABLE VARIABLE var1 AS INT NOT NULL DEFAULT 10;
+-- should to fail
+LET var1 = 10;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- should to fail
+LET var1 = 30;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DROP VARIABLE var1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 5c064a292df..b83e905284e 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1686,3 +1686,125 @@ SELECT var1;
DROP VARIABLE var1;
DROP FUNCTION vartest_fx();
+
+-- test NOT NULL
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL;
+-- should to fail
+SELECT var1;
+
+--should be ok
+LET var1 = 10;
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT 0;
+
+--should be ok
+SELECT var1;
+
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+
+DISCARD VARIABLES;
+
+-- should to fail
+LET var1 = NULL;
+
+DROP VARIABLE var1;
+
+-- test NOT NULL
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN NULL;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT vartest_fx();
+
+-- should to fail
+SELECT var1;
+
+DISCARD VARIABLES;
+
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+
+DISCARD VARIABLES;
+
+-- should be ok
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
+
+-- test IMMUTBLE
+CREATE IMMUTABLE VARIABLE var1 AS int;
+
+-- should be ok
+SELECT var1;
+-- first write should ok
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+
+DISCARD VARIABLES;
+
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+
+DISCARD VARIABLES;
+
+-- should be ok
+SELECT var1;
+-- should be ok
+LET var1 = NULL;
+-- should fail
+LET var1 = 20;
+
+DROP VARIABLE var1;
+
+CREATE IMMUTABLE VARIABLE var1 AS int DEFAULT 10;
+
+-- don't allow change when variable has DEFAULT value
+-- should to fail
+LET var1 = 20;
+
+DISCARD VARIABLES;
+
+-- should be ok
+SELECT var1;
+-- should fail
+LET var1 = 20;
+
+DROP VARIABLE var1;
+
+-- should be ok
+CREATE IMMUTABLE VARIABLE var1 AS INT NOT NULL DEFAULT 10;
+
+-- should to fail
+LET var1 = 10;
+LET var1 = 20;
+
+-- should be ok
+SELECT var1;
+
+-- should to fail
+LET var1 = 30;
+
+DROP VARIABLE var1;
--
2.48.1
[text/x-patch] v20250212-0014-Implementation-of-DEFAULT-clause-default-expressions.patch (32.1K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/11-v20250212-0014-Implementation-of-DEFAULT-clause-default-expressions.patch)
download | inline diff:
From e11cac3f3cd23fa307a4ba6d0d4794ebabc9e23b Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:03:53 +0100
Subject: [PATCH 14/22] Implementation of DEFAULT clause - default expressions
for session variables
When the evaluation of default expression fails, we remove related entry from sessionvars
hash table. Then sessionvars can contain only sucessfully initialized values. Then we don't
need special flag for badly initialized session variables.
---
doc/src/sgml/catalogs.sgml | 8 ++
doc/src/sgml/ddl.sgml | 16 ++--
doc/src/sgml/ref/create_variable.sgml | 21 +++--
doc/src/sgml/ref/discard.sgml | 3 +-
src/backend/catalog/pg_variable.c | 27 ++++++
src/backend/commands/session_variable.c | 87 ++++++++++++++++++-
src/backend/parser/gram.y | 15 +++-
src/backend/parser/parse_agg.c | 2 +
src/backend/parser/parse_expr.c | 4 +
src/backend/parser/parse_func.c | 1 +
src/bin/pg_dump/pg_dump.c | 14 +++
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_dump/t/002_pg_dump.pl | 36 ++++++++
src/bin/psql/describe.c | 4 +-
src/include/catalog/pg_variable.h | 3 +
src/include/nodes/parsenodes.h | 1 +
src/include/parser/parse_node.h | 1 +
src/test/regress/expected/psql.out | 36 ++++----
.../regress/expected/session_variables.out | 63 ++++++++++++++
src/test/regress/sql/session_variables.sql | 48 ++++++++++
20 files changed, 350 insertions(+), 41 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 687d1c8733a..27bdaf62668 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9899,6 +9899,14 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vardefexpr</structfield> <type>pg_node_tree</type>
+ </para>
+ <para>
+ The internal representation of the variable default value
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 21348c9fa89..843ec7ffea2 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5407,14 +5407,14 @@ SELECT current_user_id;
<para>
The value of a session variable is local to the current session. Retrieving
- a variable's value returns a <literal>NULL</literal>, unless its value has
- been set to something else in the current session using the
- <command>LET</command> command. Session variables are not transactional:
- any changes made to the value of a session variable in a transaction won't
- be undone if the transaction is rolled back (just like variables in
- procedural languages). Session variables themselves can be persistent
- or temporary, but their values are neither persistent nor shared (like the
- content of temporary tables).
+ a variable's value returns a <literal>NULL</literal> or a default value,
+ unless its value has been set to something else in the current session
+ using the <command>LET</command> command. Session variables are not
+ transactional: any changes made to the value of a session variable in
+ a transaction won't be undone if the transaction is rolled back (just like
+ variables in procedural languages). Session variables themselves can be
+ persistent or temporary, but their values are neither persistent nor shared
+ (like the content of temporary tables).
</para>
<para>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index c89a65fb55f..e4d8851ccb8 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -27,7 +27,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
- [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
+ [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -41,10 +41,10 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
<para>
The value of a session variable is local to the current session. Retrieving
- a session variable's value returns NULL, unless its value is set to
- something else in the current session with a <command>LET</command> command.
- The content of a session variable is not transactional. This is the same as
- regular variables in procedural languages.
+ a session variable's value returns NULL or a default value, unless its value
+ is set to something else in the current session with a <command>LET</command>
+ command. The content of a session variable is not transactional. This is the
+ same as regular variables in procedural languages.
</para>
<para>
@@ -105,6 +105,17 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-default">
+ <term><literal>DEFAULT <replaceable>default_expr</replaceable></literal></term>
+ <listitem>
+ <para>
+ The <literal>DEFAULT</literal> clause can be used to assign a default
+ value to a session variable. This expression is evaluated when the session
+ variable is first accessed for reading and had not yet been assigned a value.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createvariable-on-commit-drop">
<term><literal>ON COMMIT DROP</literal></term>
<listitem>
diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
index 61b967f9c9b..6b0cb95034f 100644
--- a/doc/src/sgml/ref/discard.sgml
+++ b/doc/src/sgml/ref/discard.sgml
@@ -71,7 +71,8 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES }
<listitem>
<para>
Resets the value of all session variables. If a variable
- is later reused, it is re-initialized to <literal>NULL</literal>.
+ is later reused, it is re-initialized to either
+ <literal>NULL</literal> or its default value.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 00c90ea6fd8..8fba4cc493b 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -24,6 +24,9 @@
#include "catalog/pg_variable.h"
#include "commands/session_variable.h"
#include "miscadmin.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_collate.h"
+#include "parser/parse_expr.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
@@ -37,6 +40,7 @@ static ObjectAddress create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ Node *varDefexpr,
VariableXactEndAction varXactEndAction);
@@ -51,6 +55,7 @@ create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ Node *varDefexpr,
VariableXactEndAction varXactEndAction)
{
Acl *varacl;
@@ -114,6 +119,11 @@ create_variable(const char *varName,
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
+ if (varDefexpr)
+ values[Anum_pg_variable_vardefexpr - 1] = CStringGetTextDatum(nodeToString(varDefexpr));
+ else
+ nulls[Anum_pg_variable_vardefexpr - 1] = true;
+
varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
varNamespace);
if (varacl != NULL)
@@ -150,6 +160,11 @@ create_variable(const char *varName,
record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
free_object_addresses(addrs);
+ /* dependency on default expr */
+ if (varDefexpr)
+ recordDependencyOnExpr(&myself, (Node *) varDefexpr,
+ NIL, DEPENDENCY_NORMAL);
+
/* dependency on owner */
recordDependencyOnOwner(VariableRelationId, varid, varOwner);
@@ -185,6 +200,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
Oid collation;
Oid typcollation;
ObjectAddress variable;
+ Node *cooked_default = NULL;
/* check consistency of arguments */
if (stmt->XactEndAction == VARIABLE_XACTEND_DROP
@@ -226,6 +242,16 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
format_type_be(typid)),
parser_errposition(pstate, stmt->collClause->location)));
+ if (stmt->defexpr)
+ {
+ cooked_default = transformExpr(pstate, stmt->defexpr,
+ EXPR_KIND_VARIABLE_DEFAULT);
+
+ cooked_default = coerce_to_specific_type(pstate,
+ cooked_default, typid, "DEFAULT");
+ assign_expr_collations(pstate, cooked_default);
+ }
+
variable = create_variable(stmt->variable->relname,
namespaceid,
typid,
@@ -233,6 +259,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
varowner,
collation,
stmt->if_not_exists,
+ cooked_default,
stmt->XactEndAction);
elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 035e5da08f2..40275abfa7e 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -22,6 +22,7 @@
#include "executor/svariableReceiver.h"
#include "funcapi.h"
#include "miscadmin.h"
+#include "optimizer/optimizer.h"
#include "rewrite/rewriteHandler.h"
#include "storage/lmgr.h"
#include "storage/proc.h"
@@ -510,11 +511,68 @@ AtEOSubXact_SessionVariables(bool isCommit,
}
}
+/*
+ * evaluate an expression
+ */
+static void
+eval_assign_defexpr(SVariable svar, HeapTuple tup)
+{
+ Datum defexpr_value;
+ bool isnull;
+
+ Assert(svar);
+ Assert(svar->is_valid);
+ Assert(HeapTupleIsValid(tup));
+
+ defexpr_value = SysCacheGetAttr(VARIABLEOID,
+ tup,
+ Anum_pg_variable_vardefexpr,
+ &isnull);
+
+ if (!isnull)
+ {
+ EState *estate;
+ ExprState *defexprs;
+ Expr *defexpr;
+ char *defexpr_str;
+ Datum value;
+ MemoryContext oldcxt;
+
+ estate = CreateExecutorState();
+
+ defexpr_str = TextDatumGetCString(defexpr_value);
+ defexpr = (Expr *) stringToNode(defexpr_str);
+
+ oldcxt = MemoryContextSwitchTo(estate->es_query_cxt);
+
+ defexpr = expression_planner((Expr *) defexpr);
+ defexprs = ExecInitExpr(defexpr, NULL);
+
+ value = ExecEvalExprSwitchContext(defexprs,
+ GetPerTupleExprContext(estate),
+ &isnull);
+
+ MemoryContextSwitchTo(oldcxt);
+
+ if (!isnull)
+ {
+ oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
+
+ svar->value = datumCopy(value, svar->typbyval, svar->typlen);
+ svar->isnull = false;
+
+ MemoryContextSwitchTo(oldcxt);
+ }
+
+ FreeExecutorState(estate);
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
static void
-setup_session_variable(SVariable svar, Oid varid)
+setup_session_variable(SVariable svar, Oid varid, bool is_write)
{
HeapTuple tup;
Form_pg_variable varform;
@@ -564,6 +622,9 @@ setup_session_variable(SVariable svar, Oid varid)
svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
ObjectIdGetDatum(varid));
+ if (!is_write)
+ eval_assign_defexpr(svar, tup);
+
ReleaseSysCache(tup);
}
@@ -593,7 +654,7 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
*/
if (!svar->is_valid)
{
- setup_session_variable(&locsvar, svar->varid);
+ setup_session_variable(&locsvar, svar->varid, false);
_svar = &locsvar;
}
else
@@ -726,7 +787,25 @@ get_session_variable(Oid varid)
*/
if (!svar->is_valid)
{
- setup_session_variable(svar, varid);
+ /* in this case we want to use defexp if it is defined */
+ PG_TRY();
+ {
+ /*
+ * In this case, the setup can execute default expression. When
+ * the execution of default expression fails, then we need to
+ * remove entry from session vars.
+ */
+ setup_session_variable(svar, varid, false);
+ }
+ PG_CATCH();
+ {
+ /* this entry cannot be valid, remove from sessionvars */
+ hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
+
+ /* propagate the error */
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)",
get_namespace_name(get_session_variable_namespace(varid)),
@@ -790,7 +869,7 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
if (!found)
{
- setup_session_variable(svar, varid);
+ setup_session_variable(svar, varid, true);
elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)",
get_namespace_name(get_session_variable_namespace(svar->varid)),
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 52e11c8d770..1d10eb7c52c 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -645,6 +645,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <partboundspec> PartitionBoundSpec
%type <list> hash_partbound
%type <defelt> hash_partbound_elem
+%type <node> OptSessionVarDefExpr
%type <node> json_format_clause
json_format_clause_opt
@@ -5264,30 +5265,36 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause XactEndActionOption
+ CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
$4->relpersistence = $2;
n->variable = $4;
n->typeName = $6;
n->collClause = (CollateClause *) $7;
- n->XactEndAction = $8;
+ n->defexpr = $8;
+ n->XactEndAction = $9;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause XactEndActionOption
+ | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
$7->relpersistence = $2;
n->variable = $7;
n->typeName = $9;
n->collClause = (CollateClause *) $10;
- n->XactEndAction = $11;
+ n->defexpr = $11;
+ n->XactEndAction = $12;
n->if_not_exists = true;
$$ = (Node *) n;
}
;
+OptSessionVarDefExpr: DEFAULT b_expr { $$ = $2; }
+ | /* EMPTY */ { $$ = NULL; }
+ ;
+
/*
* Temporary session variables can be dropped on successful
* transaction end like tables.
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 4737b04d171..54b765c8eb5 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -488,6 +488,7 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
if (isAgg)
err = _("aggregate functions are not allowed in DEFAULT expressions");
@@ -937,6 +938,7 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
err = _("window functions are not allowed in DEFAULT expressions");
break;
case EXPR_KIND_INDEX_EXPRESSION:
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index bc751b4a441..5ddd3ebbaf8 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -589,6 +589,7 @@ expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
case EXPR_KIND_JOIN_USING:
case EXPR_KIND_CYCLE_MARK:
case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_VARIABLE_DEFAULT:
result = false;
break;
}
@@ -674,6 +675,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
case EXPR_KIND_CYCLE_MARK:
case EXPR_KIND_ASSIGN_TARGET:
case EXPR_KIND_LET_TARGET:
+ case EXPR_KIND_VARIABLE_DEFAULT:
/* okay */
break;
@@ -2172,6 +2174,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
err = _("cannot use subquery in DEFAULT expression");
break;
case EXPR_KIND_INDEX_EXPRESSION:
@@ -3534,6 +3537,7 @@ ParseExprKindName(ParseExprKind exprKind)
return "CHECK";
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
return "DEFAULT";
case EXPR_KIND_INDEX_EXPRESSION:
return "index expression";
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index dc25f6dcd0e..d9f15c2618f 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2620,6 +2620,7 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location)
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
err = _("set-returning functions are not allowed in DEFAULT expressions");
break;
case EXPR_KIND_INDEX_EXPRESSION:
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index dd991b90535..7ed6fa5ac4b 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5438,6 +5438,7 @@ getVariables(Archive *fout)
int i_varnamespace;
int i_vartype;
int i_vartypname;
+ int i_vardefexpr;
int i_varxactendaction;
int i_varowner;
int i_varcollation;
@@ -5461,6 +5462,7 @@ getVariables(Archive *fout)
" THEN v.varcollation\n"
" ELSE 0\n"
" END AS varcollation,\n"
+ " pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n"
" v.varowner, v.varacl,\n"
" acldefault('V', v.varowner) AS acldefault\n"
"FROM pg_catalog.pg_variable v\n"
@@ -5477,6 +5479,7 @@ getVariables(Archive *fout)
i_varnamespace = PQfnumber(res, "varnamespace");
i_vartype = PQfnumber(res, "vartype");
i_vartypname = PQfnumber(res, "vartypname");
+ i_vardefexpr = PQfnumber(res, "vardefexpr");
i_varxactendaction = PQfnumber(res, "varxactendaction");
i_varcollation = PQfnumber(res, "varcollation");
@@ -5512,6 +5515,11 @@ getVariables(Archive *fout)
varinfo[i].dacl.initprivs = NULL;
varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner));
+ if (PQgetisnull(res, i, i_vardefexpr))
+ varinfo[i].vardefexpr = NULL;
+ else
+ varinfo[i].vardefexpr = pg_strdup(PQgetvalue(res, i, i_vardefexpr));
+
/* do not try to dump ACL if no ACL exists */
if (!PQgetisnull(res, i, i_varacl))
varinfo[i].dobj.components |= DUMP_COMPONENT_ACL;
@@ -5544,6 +5552,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
PQExpBuffer query;
char *qualvarname;
const char *vartypname;
+ const char *vardefexpr;
const char *varxactendaction;
Oid varcollation;
@@ -5556,6 +5565,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
vartypname = varinfo->vartypname;
+ vardefexpr = varinfo->vardefexpr;
varxactendaction = varinfo->varxactendaction;
varcollation = varinfo->varcollation;
@@ -5575,6 +5585,10 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
fmtQualifiedDumpable(coll));
}
+ if (vardefexpr)
+ appendPQExpBuffer(query, " DEFAULT %s",
+ vardefexpr);
+
if (strcmp(varxactendaction, "r") == 0)
appendPQExpBuffer(query, " ON TRANSACTION END RESET");
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index e815b411f0f..ef1ba042132 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -718,6 +718,7 @@ typedef struct _VariableInfo
DumpableAcl dacl;
Oid vartype;
char *vartypname;
+ char *vardefexpr;
char *varxactendaction;
Oid varcollation;
const char *rolname; /* name of owner, or empty string */
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 4a70f4cd699..fb25f80a852 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4072,6 +4072,42 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable DEFAULT' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable3 AS integer DEFAULT 10;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable3 AS integer DEFAULT 10;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
+ 'CREATE VARIABLE test_variable DEFAULT ON TRANSACTION END RESET' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable4 AS integer DEFAULT 10 ON TRANSACTION END RESET',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable4 AS integer DEFAULT 10 ON TRANSACTION END RESET;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index d3b1442eb2f..b5e5d073f9c 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5352,6 +5352,7 @@ listVariables(const char *pattern, bool verbose)
" (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
" WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
+ " pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
" WHEN 'r' THEN 'ON TRANSACTION END RESET'\n"
@@ -5361,6 +5362,7 @@ listVariables(const char *pattern, bool verbose)
gettext_noop("Type"),
gettext_noop("Collation"),
gettext_noop("Owner"),
+ gettext_noop("Default"),
gettext_noop("Transactional end action"));
if (verbose)
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 008f2ee7c17..09dd44a44e1 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -68,6 +68,9 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* access permissions */
aclitem varacl[1] BKI_DEFAULT(_null_);
+ /* list of expression trees for variable default (NULL if none) */
+ pg_node_tree vardefexpr BKI_DEFAULT(_null_);
+
#endif
} FormData_pg_variable;
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 04d4a853a3c..d1d2ac91fb5 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3535,6 +3535,7 @@ typedef struct CreateSessionVarStmt
TypeName *typeName; /* the type of variable */
CollateClause *collClause;
bool if_not_exists; /* do nothing if it already exists */
+ Node *defexpr; /* default expression */
char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index bb6b9251083..e7801640dcf 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -84,6 +84,7 @@ typedef enum ParseExprKind
EXPR_KIND_CYCLE_MARK, /* cycle mark value */
EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */
EXPR_KIND_LET_TARGET, /* LET target */
+ EXPR_KIND_VARIABLE_DEFAULT, /* default value for session variable */
} ParseExprKind;
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 3ddbcc7cc2a..999fc88d1e1 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6020,20 +6020,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+--------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+---------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+--------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+---------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6501,9 +6501,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action
---------+------+------+-----------+-------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action
+--------+------+------+-----------+-------+---------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6676,9 +6676,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action
---------+------+------+-----------+-------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action
+--------+------+------+-----------+-------+---------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6815,9 +6815,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action
---------+------+------+-----------+-------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action
+--------+------+------+-----------+-------+---------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index e39e7c6c2d6..b5adb797801 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2389,3 +2389,66 @@ SELECT var1 IS NULL;
(1 row)
DROP VARIABLE var1;
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE NOTICE 'vartest_fx executed';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+CREATE VARIABLE var1 AS int DEFAULT vartest_fx();
+-- vartest_fx should be protected by dep, should fail
+DROP FUNCTION vartest_fx();
+ERROR: cannot drop function vartest_fx() because other objects depend on it
+DETAIL: session variable var1 depends on function vartest_fx()
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+SELECT var1;
+NOTICE: vartest_fx executed
+ var1
+------
+ 0
+(1 row)
+
+-- the defexpr should be evaluated only once
+SELECT var1;
+ var1
+------
+ 0
+(1 row)
+
+DISCARD VARIABLES;
+-- in this case, the defexpr should not be evaluated
+LET var1 = 100;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DISCARD VARIABLES;
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE EXCEPTION 'vartest_fx is executing';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+-- should to fail, but not to crash
+SELECT var1;
+ERROR: vartest_fx is executing
+CONTEXT: PL/pgSQL function vartest_fx() line 3 at RAISE
+-- again
+SELECT var1;
+ERROR: vartest_fx is executing
+CONTEXT: PL/pgSQL function vartest_fx() line 3 at RAISE
+-- but we can write
+LET var1 = 100;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 960fe07933a..5c064a292df 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1638,3 +1638,51 @@ ROLLBACK;
SELECT var1 IS NULL;
DROP VARIABLE var1;
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE NOTICE 'vartest_fx executed';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE VARIABLE var1 AS int DEFAULT vartest_fx();
+
+-- vartest_fx should be protected by dep, should fail
+DROP FUNCTION vartest_fx();
+
+-- should be ok
+SELECT var1;
+
+-- the defexpr should be evaluated only once
+SELECT var1;
+
+DISCARD VARIABLES;
+
+-- in this case, the defexpr should not be evaluated
+LET var1 = 100;
+SELECT var1;
+
+DISCARD VARIABLES;
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE EXCEPTION 'vartest_fx is executing';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+
+-- should to fail, but not to crash
+SELECT var1;
+
+-- again
+SELECT var1;
+
+-- but we can write
+LET var1 = 100;
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
--
2.48.1
[text/x-patch] v20250212-0013-Implementation-ON-TRANSACTION-END-RESET-clause.patch (14.6K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/12-v20250212-0013-Implementation-ON-TRANSACTION-END-RESET-clause.patch)
download | inline diff:
From 10ec71d99bdf52608945d29e9498e720c5266feb Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:02:13 +0100
Subject: [PATCH 13/22] Implementation ON TRANSACTION END RESET clause
This is simple patch - just add special flag to session variable memory entry.
The entries with active this flag are removed from sessionvars hash table
at transaction end. The "TRANSACTION END" is synonyms for "COMMIT ROLLBACK"
but the "TRANSACTION END" is more illustrative and less confusing then "COMMIT ROLLBACK".
---
doc/src/sgml/catalogs.sgml | 3 +-
doc/src/sgml/ref/create_variable.sgml | 13 ++++-
src/backend/commands/session_variable.c | 51 +++++++++++++++++++
src/backend/parser/gram.y | 1 +
src/bin/pg_dump/pg_dump.c | 11 ++++
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_dump/t/002_pg_dump.pl | 18 +++++++
src/bin/psql/describe.c | 1 +
src/include/catalog/pg_variable.h | 1 +
.../isolation/expected/session-variable.out | 4 +-
.../isolation/specs/session-variable.spec | 4 +-
.../regress/expected/session_variables.out | 34 +++++++++++++
src/test/regress/sql/session_variables.sql | 20 ++++++++
13 files changed, 158 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 09b635c234a..687d1c8733a 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9871,7 +9871,8 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para>
<para>
Action performed at end of transaction:
- <literal>n</literal> = no action, <literal>d</literal> = drop the variable.
+ <literal>n</literal> = no action, <literal>d</literal> = drop the variable,
+ <literal>r</literal> = reset the variable to its default value.
</para></entry>
</row>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index a88e0175bea..c89a65fb55f 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -27,7 +27,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
- [ ON COMMIT DROP ]
+ [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -117,6 +117,17 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-on-transaction-end-reset">
+ <term><literal>ON TRANSACTION END RESET</literal></term>
+ <listitem>
+ <para>
+ The <literal>ON TRANSACTION END RESET</literal> clause causes the session
+ variable to be reset to its default value when the transaction is committed
+ or rolled back.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</refsect1>
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 03e0b6900ca..035e5da08f2 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -83,6 +83,8 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ bool reset_at_eox;
+
/*
* Top level local transaction id of the last transaction that dropped the
* variable, if any. We need this information to avoid freeing memory for
@@ -110,6 +112,12 @@ static MemoryContext SVariableMemoryContext = NULL;
/* becomes true when we receive a sinval message */
static bool needs_validation = false;
+/*
+ * true, when some used session variable has ON COMMIT DROP
+ * or ON TRANSACTION END RESET clauses
+ */
+static bool has_session_variables_with_reset_at_eox = false;
+
/*
* The content of dropped session variables is not removed immediately. If
* possible, we do that at the end of the transaction. But we cannot do that
@@ -385,6 +393,32 @@ remove_invalid_session_variables(bool atEOX)
}
}
+/*
+ * remove entries marked as "reset_at_eox"
+ */
+static void
+remove_session_variables_with_reset_at_eox(void)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ if (!sessionvars)
+ return;
+
+ /* leave quckly, when there are not that variables */
+ if (!has_session_variables_with_reset_at_eox)
+ return;
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (svar->reset_at_eox)
+ hash_search(sessionvars, &svar->varid, HASH_REMOVE, NULL);
+ }
+
+ has_session_variables_with_reset_at_eox = false;
+}
+
/*
* Perform ON COMMIT DROP for temporary session variables,
* and remove all dropped variables from memory.
@@ -392,6 +426,8 @@ remove_invalid_session_variables(bool atEOX)
void
AtPreEOXact_SessionVariables(bool isCommit)
{
+ remove_session_variables_with_reset_at_eox();
+
if (isCommit)
{
if (xact_drop_items)
@@ -503,6 +539,21 @@ setup_session_variable(SVariable svar, Oid varid)
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+ /*
+ * We don't need to explicitly reset variables marked ON COMMIT DROP. It
+ * can be done by sinval message processing. But this processing can be
+ * postponed due aborted transaction. On second hand there is not a
+ * reason, why don't do it at transaction end immediately.
+ */
+ if (varform->varxactendaction == VARIABLE_XACTEND_RESET ||
+ varform->varxactendaction == VARIABLE_XACTEND_DROP)
+ {
+ svar->reset_at_eox = true;
+ has_session_variables_with_reset_at_eox = true;
+ }
+ else
+ svar->reset_at_eox = false;
+
svar->drop_lxid = InvalidTransactionId;
svar->isnull = true;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 2af037d2669..52e11c8d770 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -5293,6 +5293,7 @@ CreateSessionVarStmt:
* transaction end like tables.
*/
XactEndActionOption: ON COMMIT DROP { $$ = VARIABLE_XACTEND_DROP; }
+ | ON TRANSACTION END_P RESET { $$ = VARIABLE_XACTEND_RESET; }
| /*EMPTY*/ { $$ = VARIABLE_XACTEND_NOOP; }
;
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 8f8f1185f16..dd991b90535 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5438,6 +5438,7 @@ getVariables(Archive *fout)
int i_varnamespace;
int i_vartype;
int i_vartypname;
+ int i_varxactendaction;
int i_varowner;
int i_varcollation;
int i_varacl;
@@ -5453,6 +5454,7 @@ getVariables(Archive *fout)
/* get the variables in current database */
appendPQExpBuffer(query,
"SELECT v.tableoid, v.oid, v.varname,\n"
+ " v.varxactendaction,\n"
" v.varnamespace, v.vartype,\n"
" pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n"
" CASE WHEN v.varcollation <> t.typcollation "
@@ -5475,6 +5477,7 @@ getVariables(Archive *fout)
i_varnamespace = PQfnumber(res, "varnamespace");
i_vartype = PQfnumber(res, "vartype");
i_vartypname = PQfnumber(res, "vartypname");
+ i_varxactendaction = PQfnumber(res, "varxactendaction");
i_varcollation = PQfnumber(res, "varcollation");
i_varowner = PQfnumber(res, "varowner");
@@ -5498,6 +5501,9 @@ getVariables(Archive *fout)
varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype));
varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname));
+ varinfo[i].varxactendaction =
+ pg_strdup(PQgetvalue(res, i, i_varxactendaction));
+
varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
@@ -5538,6 +5544,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
PQExpBuffer query;
char *qualvarname;
const char *vartypname;
+ const char *varxactendaction;
Oid varcollation;
/* skip if not to be dumped */
@@ -5549,6 +5556,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
vartypname = varinfo->vartypname;
+ varxactendaction = varinfo->varxactendaction;
varcollation = varinfo->varcollation;
appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
@@ -5567,6 +5575,9 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
fmtQualifiedDumpable(coll));
}
+ if (strcmp(varxactendaction, "r") == 0)
+ appendPQExpBuffer(query, " ON TRANSACTION END RESET");
+
appendPQExpBuffer(query, ";\n");
if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index 125384cf3f0..e815b411f0f 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -718,6 +718,7 @@ typedef struct _VariableInfo
DumpableAcl dacl;
Oid vartype;
char *vartypname;
+ char *varxactendaction;
Oid varcollation;
const char *rolname; /* name of owner, or empty string */
} VariableInfo;
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index b84dcf0cab9..4a70f4cd699 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4054,6 +4054,24 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable ON TRANSACTION END RESET' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable2 AS integer ON TRANSACTION END RESET;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable2 AS integer ON TRANSACTION END RESET;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a3fca34c7d7..d3b1442eb2f 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5354,6 +5354,7 @@ listVariables(const char *pattern, bool verbose)
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
+ " WHEN 'r' THEN 'ON TRANSACTION END RESET'\n"
" END as \"%s\"\n",
gettext_noop("Schema"),
gettext_noop("Name"),
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 0fc672bc2ba..008f2ee7c17 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -75,6 +75,7 @@ typedef enum VariableXactEndAction
{
VARIABLE_XACTEND_NOOP = 'n', /* NOOP */
VARIABLE_XACTEND_DROP = 'd', /* ON COMMIT DROP */
+ VARIABLE_XACTEND_RESET = 'r', /* ON TRANSACTION END RESET */
} VariableXactEndAction;
/* ----------------
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
index a609797dc5d..e9a254bcd12 100644
--- a/src/test/isolation/expected/session-variable.out
+++ b/src/test/isolation/expected/session-variable.out
@@ -86,11 +86,12 @@ myvar
step sr1: ROLLBACK;
-starting permutation: create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
+starting permutation: create3 let3 s3 o_c_d o_eox_r create4 let4 drop4 drop3 inval3 discard sc3 clean state
step create3: CREATE VARIABLE myvar3 AS text;
step let3: LET myvar3 = 'test';
step s3: BEGIN;
step o_c_d: CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP;
+step o_eox_r: CREATE VARIABLE myvar_o_eox_r AS text ON TRANSACTION END RESET; LET myvar_o_eox_r = 'test';
step create4: CREATE VARIABLE myvar4 AS text;
step let4: LET myvar4 = 'test';
step drop4: DROP VARIABLE myvar4;
@@ -103,6 +104,7 @@ t
step discard: DISCARD VARIABLES;
step sc3: COMMIT;
+step clean: DROP VARIABLE myvar_o_eox_r;
step state: SELECT varname FROM pg_variable;
varname
-------
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
index 45e65d4085d..5d089c8a4ed 100644
--- a/src/test/isolation/specs/session-variable.spec
+++ b/src/test/isolation/specs/session-variable.spec
@@ -25,12 +25,14 @@ session s3
step s3 { BEGIN; }
step let3 { LET myvar3 = 'test'; }
step o_c_d { CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP; }
+step o_eox_r { CREATE VARIABLE myvar_o_eox_r AS text ON TRANSACTION END RESET; LET myvar_o_eox_r = 'test'; }
step create4 { CREATE VARIABLE myvar4 AS text; }
step let4 { LET myvar4 = 'test'; }
step drop4 { DROP VARIABLE myvar4; }
step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; }
step discard { DISCARD VARIABLES; }
step sc3 { COMMIT; }
+step clean { DROP VARIABLE myvar_o_eox_r; }
step state { SELECT varname FROM pg_variable; }
session s4
@@ -48,4 +50,4 @@ permutation let val dbg drop create dbg val
# calling the dbg step after the concurrent drop
permutation let val s1 dbg drop create dbg val sr1
# test for DISCARD ALL when all internal queues have actions registered
-permutation create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
+permutation create3 let3 s3 o_c_d o_eox_r create4 let4 drop4 drop3 inval3 discard sc3 clean state
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 2621591a16a..e39e7c6c2d6 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2355,3 +2355,37 @@ SELECT count(*) FROM pg_session_variables();
0
(1 row)
+CREATE VARIABLE var1 AS int ON TRANSACTION END RESET;
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+COMMIT;
+-- should be NULL;
+SELECT var1 IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be NULL
+SELECT var1 IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+DROP VARIABLE var1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 610261a617f..960fe07933a 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1618,3 +1618,23 @@ COMMIT;
SELECT count(*) FROM pg_variable WHERE varname = 'var1';
-- should be zero
SELECT count(*) FROM pg_session_variables();
+
+CREATE VARIABLE var1 AS int ON TRANSACTION END RESET;
+
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+COMMIT;
+
+-- should be NULL;
+SELECT var1 IS NULL;
+
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+ROLLBACK;
+
+-- should be NULL
+SELECT var1 IS NULL;
+
+DROP VARIABLE var1;
--
2.48.1
[text/x-patch] v20250212-0012-implementation-of-temporary-session-variables.patch (40.7K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/13-v20250212-0012-implementation-of-temporary-session-variables.patch)
download | inline diff:
From af6bcff9f2683e2b64e995b3cef9cdf5c82d980a Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:00:28 +0100
Subject: [PATCH 12/22] implementation of temporary session variables
The temporary variables are created inside temp schema and they are dropped by dropping
this schema. For consistency with temp tables, the CREATE TEMP VARIABLE command supports
ON COMMIT DROP clause. The temporary variables with this clause are collected in xact_drop_items
list. This list should be carefully maintained and can contain only valid entries (not
yet dropped). From this reasons now the subcommit and subaborting have to be handled.
---
doc/src/sgml/catalogs.sgml | 10 +
doc/src/sgml/ddl.sgml | 6 +-
doc/src/sgml/ref/create_variable.sgml | 15 +-
src/backend/access/transam/xact.c | 9 +
src/backend/catalog/pg_variable.c | 27 ++-
src/backend/commands/session_variable.c | 218 +++++++++++++++++-
src/backend/commands/view.c | 2 +-
src/backend/parser/analyze.c | 4 +-
src/backend/parser/gram.y | 30 ++-
src/backend/parser/parse_relation.c | 22 +-
src/bin/psql/describe.c | 10 +-
src/bin/psql/tab-complete.in.c | 5 +-
src/include/catalog/pg_variable.h | 9 +
src/include/commands/session_variable.h | 6 +-
src/include/nodes/parsenodes.h | 1 +
src/include/nodes/primnodes.h | 4 +-
src/include/parser/parse_relation.h | 2 +-
.../isolation/expected/session-variable.out | 3 +-
.../isolation/specs/session-variable.spec | 3 +-
src/test/regress/expected/psql.out | 36 +--
.../regress/expected/session_variables.out | 120 ++++++++++
src/test/regress/sql/session_variables.sql | 66 ++++++
src/tools/pgindent/typedefs.list | 1 +
23 files changed, 544 insertions(+), 65 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 4f502274bfa..09b635c234a 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9865,6 +9865,16 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varxactendaction</structfield> <type>char</type>
+ </para>
+ <para>
+ Action performed at end of transaction:
+ <literal>n</literal> = no action, <literal>d</literal> = drop the variable.
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>varcollation</structfield> <type>oid</type>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 748219b3804..21348c9fa89 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5412,9 +5412,9 @@ SELECT current_user_id;
<command>LET</command> command. Session variables are not transactional:
any changes made to the value of a session variable in a transaction won't
be undone if the transaction is rolled back (just like variables in
- procedural languages). Session variables themselves are persistent, but
- their values are neither persistent nor shared (like the content of
- temporary tables).
+ procedural languages). Session variables themselves can be persistent
+ or temporary, but their values are neither persistent nor shared (like the
+ content of temporary tables).
</para>
<para>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index cd9ff63975a..a88e0175bea 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -26,7 +26,8 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+ [ ON COMMIT DROP ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -104,6 +105,18 @@ CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceab
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-on-commit-drop">
+ <term><literal>ON COMMIT DROP</literal></term>
+ <listitem>
+ <para>
+ The <literal>ON COMMIT DROP</literal> clause specifies the behaviour of a
+ temporary session variable at transaction commit. With this clause, the
+ session variable is dropped at commit time. The clause is only allowed
+ for temporary variables.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</refsect1>
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index d331ab90d78..6168415f8c3 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -36,6 +36,7 @@
#include "catalog/pg_enum.h"
#include "catalog/storage.h"
#include "commands/async.h"
+#include "commands/session_variable.h"
#include "commands/tablecmds.h"
#include "commands/trigger.h"
#include "common/pg_prng.h"
@@ -2316,6 +2317,9 @@ CommitTransaction(void)
*/
smgrDoPendingSyncs(true, is_parallel_worker);
+ /* remove values of dropped session variables from memory */
+ AtPreEOXact_SessionVariables(true);
+
/* close large objects before lower-level cleanup */
AtEOXact_LargeObject(true);
@@ -2912,6 +2916,7 @@ AbortTransaction(void)
AtAbort_Portals();
smgrDoPendingSyncs(false, is_parallel_worker);
AtEOXact_LargeObject(false);
+ AtPreEOXact_SessionVariables(false);
AtAbort_Notify();
AtEOXact_RelationMap(false, is_parallel_worker);
AtAbort_Twophase();
@@ -5177,6 +5182,8 @@ CommitSubTransaction(void)
AtEOSubXact_SPI(true, s->subTransactionId);
AtEOSubXact_on_commit_actions(true, s->subTransactionId,
s->parent->subTransactionId);
+ AtEOSubXact_SessionVariables(true, s->subTransactionId,
+ s->parent->subTransactionId);
AtEOSubXact_Namespace(true, s->subTransactionId,
s->parent->subTransactionId);
AtEOSubXact_Files(true, s->subTransactionId,
@@ -5342,6 +5349,8 @@ AbortSubTransaction(void)
AtEOSubXact_SPI(false, s->subTransactionId);
AtEOSubXact_on_commit_actions(false, s->subTransactionId,
s->parent->subTransactionId);
+ AtEOSubXact_SessionVariables(false, s->subTransactionId,
+ s->parent->subTransactionId);
AtEOSubXact_Namespace(false, s->subTransactionId,
s->parent->subTransactionId);
AtEOSubXact_Files(false, s->subTransactionId,
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index d672d2a9cb3..00c90ea6fd8 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -36,7 +36,8 @@ static ObjectAddress create_variable(const char *varName,
int32 varTypmod,
Oid varOwner,
Oid varCollation,
- bool if_not_exists);
+ bool if_not_exists,
+ VariableXactEndAction varXactEndAction);
/*
@@ -49,7 +50,8 @@ create_variable(const char *varName,
int32 varTypmod,
Oid varOwner,
Oid varCollation,
- bool if_not_exists)
+ bool if_not_exists,
+ VariableXactEndAction varXactEndAction)
{
Acl *varacl;
NameData varname;
@@ -110,6 +112,7 @@ create_variable(const char *varName,
values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+ values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
varNamespace);
@@ -183,6 +186,13 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
Oid typcollation;
ObjectAddress variable;
+ /* check consistency of arguments */
+ if (stmt->XactEndAction == VARIABLE_XACTEND_DROP
+ && stmt->variable->relpersistence != RELPERSISTENCE_TEMP)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+ errmsg("ON COMMIT DROP can only be used on temporary variables")));
+
namespaceid =
RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL);
@@ -222,11 +232,17 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
typmod,
varowner,
collation,
- stmt->if_not_exists);
+ stmt->if_not_exists,
+ stmt->XactEndAction);
elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
stmt->variable->relname, variable.objectId);
+ /* we want SessionVariableCreatePostprocess to see the catalog changes. */
+ CommandCounterIncrement();
+
+ SessionVariableCreatePostprocess(variable.objectId, stmt->XactEndAction);
+
return variable;
}
@@ -239,6 +255,7 @@ DropVariableById(Oid varid)
{
Relation rel;
HeapTuple tup;
+ char XactEndAction;
rel = table_open(VariableRelationId, RowExclusiveLock);
@@ -247,6 +264,8 @@ DropVariableById(Oid varid)
if (!HeapTupleIsValid(tup))
elog(ERROR, "cache lookup failed for variable %u", varid);
+ XactEndAction = ((Form_pg_variable) GETSTRUCT(tup))->varxactendaction;
+
CatalogTupleDelete(rel, &tup->t_self);
ReleaseSysCache(tup);
@@ -254,5 +273,5 @@ DropVariableById(Oid varid)
table_close(rel, RowExclusiveLock);
/* do the necessary cleanup in local memory, if needed */
- SessionVariableDropPostprocess(varid);
+ SessionVariableDropPostprocess(varid, XactEndAction);
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 4a29ed6e0c3..03e0b6900ca 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -16,6 +16,8 @@
#include "access/xact.h"
#include "catalog/pg_variable.h"
+#include "catalog/dependency.h"
+#include "catalog/namespace.h"
#include "commands/session_variable.h"
#include "executor/svariableReceiver.h"
#include "funcapi.h"
@@ -31,6 +33,19 @@
#include "utils/snapmgr.h"
#include "utils/syscache.h"
+typedef struct SVariableXActDropItem
+{
+ Oid varid; /* varid of session variable */
+
+ /*
+ * creating_subid is the ID of the creating subxact. If the action was
+ * unregistered during the current transaction, deleting_subid is the ID
+ * of the deleting subxact, otherwise InvalidSubTransactionId.
+ */
+ SubTransactionId creating_subid;
+ SubTransactionId deleting_subid;
+} SVariableXActDropItem;
+
/*
* The values of session variables are stored in the backend's private memory
* in the dedicated memory context SVariableMemoryContext in binary format.
@@ -96,13 +111,21 @@ static MemoryContext SVariableMemoryContext = NULL;
static bool needs_validation = false;
/*
- * The content of dropped session variables is not removed immediately. We do
- * that in the next transaction that reads or writes a session variable.
- * "validated_lxid" stores the transaction that performed said validation, so
- * that we can avoid repeating the effort.
+ * The content of dropped session variables is not removed immediately. If
+ * possible, we do that at the end of the transaction. But we cannot do that
+ * if the transaction aborted, because we lost access to the system catalog.
+ * In that case, we clean up in the next transaction that reads or writes a
+ * session variable. "validated_lxid" stores the transaction that performed
+ * said validation, so that we can avoid repeating the effort.
*/
static LocalTransactionId validated_lxid = InvalidLocalTransactionId;
+/* list holds fields of SVariableXActDropItem type */
+static List *xact_drop_items = NIL;
+
+static void register_session_variable_xact_drop(Oid varid);
+static void unregister_session_variable_xact_drop(Oid varid);
+
/*
* Callback function for session variable invalidation.
*/
@@ -139,16 +162,45 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
}
}
+/*
+ * Do the necessary work to setup local memory management of a new
+ * variable.
+ *
+ * Caller should already have created the necessary entry in catalog
+ * and made them visible.
+ */
+void
+SessionVariableCreatePostprocess(Oid varid, char XactEndAction)
+{
+ /*
+ * For temporary variables, we need to create a new end of xact action to
+ * ensure deletion from catalog.
+ */
+ if (XactEndAction == VARIABLE_XACTEND_DROP)
+ {
+ Assert(isTempNamespace(get_session_variable_namespace(varid)));
+
+ register_session_variable_xact_drop(varid);
+ }
+}
+
/*
* Handle the local memory cleanup for a DROP VARIABLE command.
*
* Caller should take care of removing the pg_variable entry first.
*/
void
-SessionVariableDropPostprocess(Oid varid)
+SessionVariableDropPostprocess(Oid varid, char XactEndAction)
{
Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid));
+ if (XactEndAction == VARIABLE_XACTEND_DROP)
+ {
+ Assert(isTempNamespace(get_session_variable_namespace(varid)));
+
+ unregister_session_variable_xact_drop(varid);
+ }
+
if (sessionvars)
{
bool found;
@@ -170,6 +222,57 @@ SessionVariableDropPostprocess(Oid varid)
}
}
+/*
+ * Registration of actions to be executed on session variables at transaction
+ * end time. We want to drop temporary session variables with clause ON COMMIT
+ * DROP.
+ */
+
+/*
+ * Register a session variable xact action.
+ */
+static void
+register_session_variable_xact_drop(Oid varid)
+{
+ SVariableXActDropItem *xact_ai;
+ MemoryContext oldcxt;
+
+ oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
+
+ xact_ai = (SVariableXActDropItem *)
+ palloc(sizeof(SVariableXActDropItem));
+
+ xact_ai->varid = varid;
+
+ xact_ai->creating_subid = GetCurrentSubTransactionId();
+ xact_ai->deleting_subid = InvalidSubTransactionId;
+
+ xact_drop_items = lcons(xact_ai, xact_drop_items);
+
+ MemoryContextSwitchTo(oldcxt);
+}
+
+/*
+ * Unregister an id of a given session variable from drop list. In this
+ * moment, the action is just marked as deleted by setting deleting_subid. The
+ * calling even might be rollbacked, in which case we should not lose this
+ * action.
+ */
+static void
+unregister_session_variable_xact_drop(Oid varid)
+{
+ ListCell *l;
+
+ foreach(l, xact_drop_items)
+ {
+ SVariableXActDropItem *xact_ai =
+ (SVariableXActDropItem *) lfirst(l);
+
+ if (xact_ai->varid == varid)
+ xact_ai->deleting_subid = GetCurrentSubTransactionId();
+ }
+}
+
/*
* Release stored value, free memory
*/
@@ -222,9 +325,11 @@ is_session_variable_valid(SVariable svar)
/*
* Check all potentially invalid session variable data in local memory and free
* the memory for all invalid ones. This function is called before any read or
- * write of a session variable. Freeing of a variable's memory is postponed if
- * the variable has been dropped by the current transaction, since that
- * operation could still be rolled back.
+ * write of a session variable or when the transaction ends. At the end of a
+ * transaction (atEOX is true) we can discard all invalid variables. Inside a
+ * transaction (atEOX is false) we postpone freeing a variable's memory if the
+ * variable has been dropped by the current transaction, since that operation
+ * could still be rolled back.
*
* It is possible that we receive a cache invalidation message while
* remove_invalid_session_variables() is executing, so we cannot guarantee that
@@ -232,7 +337,7 @@ is_session_variable_valid(SVariable svar)
* done. However, we can guarantee that all entries get checked once.
*/
static void
-remove_invalid_session_variables(void)
+remove_invalid_session_variables(bool atEOX)
{
HASH_SEQ_STATUS status;
SVariable svar;
@@ -259,7 +364,7 @@ remove_invalid_session_variables(void)
{
if (!svar->is_valid)
{
- if (svar->drop_lxid == MyProc->vxid.lxid)
+ if (!atEOX && svar->drop_lxid == MyProc->vxid.lxid)
{
/* try again in the next transaction */
needs_validation = true;
@@ -280,6 +385,95 @@ remove_invalid_session_variables(void)
}
}
+/*
+ * Perform ON COMMIT DROP for temporary session variables,
+ * and remove all dropped variables from memory.
+ */
+void
+AtPreEOXact_SessionVariables(bool isCommit)
+{
+ if (isCommit)
+ {
+ if (xact_drop_items)
+ {
+ ListCell *l;
+
+ foreach(l, xact_drop_items)
+ {
+ SVariableXActDropItem *xact_ai =
+ (SVariableXActDropItem *) lfirst(l);
+
+ /* iterate only over entries that are still pending */
+ if (xact_ai->deleting_subid == InvalidSubTransactionId)
+ {
+ ObjectAddress object;
+
+ object.classId = VariableRelationId;
+ object.objectId = xact_ai->varid;
+ object.objectSubId = 0;
+
+ /*
+ * Since this is an automatic drop, rather than one
+ * directly initiated by the user, we pass the
+ * PERFORM_DELETION_INTERNAL flag.
+ */
+ elog(DEBUG1, "session variable (oid:%u) will be deleted (forced by ON COMMIT DROP clause)",
+ xact_ai->varid);
+
+ performDeletion(&object, DROP_CASCADE,
+ PERFORM_DELETION_INTERNAL |
+ PERFORM_DELETION_QUIETLY);
+ }
+ }
+ }
+
+ remove_invalid_session_variables(true);
+ }
+
+ /*
+ * We have to clean xact_drop_items. All related variables are dropped
+ * now, or lost inside aborted transaction.
+ */
+ list_free_deep(xact_drop_items);
+ xact_drop_items = NULL;
+}
+
+/*
+ * Post-subcommit or post-subabort cleanup of xact drop list.
+ *
+ * During subabort, we can immediately remove entries created during this
+ * subtransaction. During subcommit, just transfer entries marked during
+ * this subtransaction as being the parent's responsibility.
+ */
+void
+AtEOSubXact_SessionVariables(bool isCommit,
+ SubTransactionId mySubid,
+ SubTransactionId parentSubid)
+{
+ ListCell *cur_item;
+
+ foreach(cur_item, xact_drop_items)
+ {
+ SVariableXActDropItem *xact_ai =
+ (SVariableXActDropItem *) lfirst(cur_item);
+
+ if (!isCommit && xact_ai->creating_subid == mySubid)
+ {
+ /* cur_item must be removed */
+ xact_drop_items = foreach_delete_current(xact_drop_items, cur_item);
+ pfree(xact_ai);
+ }
+ else
+ {
+ /* cur_item must be preserved */
+ if (xact_ai->creating_subid == mySubid)
+ xact_ai->creating_subid = parentSubid;
+ if (xact_ai->deleting_subid == mySubid)
+ xact_ai->deleting_subid = isCommit ? parentSubid : InvalidSubTransactionId;
+ }
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
@@ -438,7 +632,7 @@ get_session_variable(Oid varid)
validated_lxid != MyProc->vxid.lxid)
{
/* free the memory from dropped session variables */
- remove_invalid_session_variables();
+ remove_invalid_session_variables(false);
/* don't repeat the above step in the same transaction */
validated_lxid = MyProc->vxid.lxid;
@@ -534,7 +728,7 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
validated_lxid != MyProc->vxid.lxid)
{
/* free the memory from dropped session variables */
- remove_invalid_session_variables();
+ remove_invalid_session_variables(false);
/* don't repeat the above step in the same transaction */
validated_lxid = MyProc->vxid.lxid;
diff --git a/src/backend/commands/view.c b/src/backend/commands/view.c
index 6f0301555e0..6bef9a2612a 100644
--- a/src/backend/commands/view.c
+++ b/src/backend/commands/view.c
@@ -484,7 +484,7 @@ DefineView(ViewStmt *stmt, const char *queryString,
*/
view = copyObject(stmt->view); /* don't corrupt original command */
if (view->relpersistence == RELPERSISTENCE_PERMANENT
- && isQueryUsingTempRelation(viewParse))
+ && isQueryUsingTempObject(viewParse))
{
view->relpersistence = RELPERSISTENCE_TEMP;
ereport(NOTICE,
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 725f678e2fa..c0c3abd7a0e 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -3491,10 +3491,10 @@ transformCreateTableAsStmt(ParseState *pstate, CreateTableAsStmt *stmt)
* creation query. It would be hard to refresh data or incrementally
* maintain it if a source disappeared.
*/
- if (isQueryUsingTempRelation(query))
+ if (isQueryUsingTempObject(query))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("materialized views must not use temporary tables or views")));
+ errmsg("materialized views must not use temporary tables, views or session variables")));
/*
* A materialized view would either need to save parameters for use in
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index b5bd1093572..2af037d2669 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -473,6 +473,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <ival> OptTemp
%type <ival> OptNoLog
%type <oncommit> OnCommitOption
+%type <ival> XactEndActionOption
%type <ival> for_locking_strength
%type <node> for_locking_item
@@ -5263,26 +5264,39 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause
+ CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- n->variable = $3;
- n->typeName = $5;
- n->collClause = (CollateClause *) $6;
+ $4->relpersistence = $2;
+ n->variable = $4;
+ n->typeName = $6;
+ n->collClause = (CollateClause *) $7;
+ n->XactEndAction = $8;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause
+ | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- n->variable = $6;
- n->typeName = $8;
- n->collClause = (CollateClause *) $9;
+ $7->relpersistence = $2;
+ n->variable = $7;
+ n->typeName = $9;
+ n->collClause = (CollateClause *) $10;
+ n->XactEndAction = $11;
n->if_not_exists = true;
$$ = (Node *) n;
}
;
+/*
+ * Temporary session variables can be dropped on successful
+ * transaction end like tables.
+ */
+XactEndActionOption: ON COMMIT DROP { $$ = VARIABLE_XACTEND_DROP; }
+ | /*EMPTY*/ { $$ = VARIABLE_XACTEND_NOOP; }
+ ;
+
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index 04ecf64b1fc..bec6947ea2d 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -103,7 +103,7 @@ static void expandTupleDesc(TupleDesc tupdesc, Alias *eref,
static int specialAttNum(const char *attname);
static bool rte_visible_if_lateral(ParseState *pstate, RangeTblEntry *rte);
static bool rte_visible_if_qualified(ParseState *pstate, RangeTblEntry *rte);
-static bool isQueryUsingTempRelation_walker(Node *node, void *context);
+static bool isQueryUsingTempObject_walker(Node *node, void *context);
/*
@@ -3927,13 +3927,13 @@ rte_visible_if_qualified(ParseState *pstate, RangeTblEntry *rte)
* the query is a temporary relation (table, view, or materialized view).
*/
bool
-isQueryUsingTempRelation(Query *query)
+isQueryUsingTempObject(Query *query)
{
- return isQueryUsingTempRelation_walker((Node *) query, NULL);
+ return isQueryUsingTempObject_walker((Node *) query, NULL);
}
static bool
-isQueryUsingTempRelation_walker(Node *node, void *context)
+isQueryUsingTempObject_walker(Node *node, void *context)
{
if (node == NULL)
return false;
@@ -3959,13 +3959,23 @@ isQueryUsingTempRelation_walker(Node *node, void *context)
}
return query_tree_walker(query,
- isQueryUsingTempRelation_walker,
+ isQueryUsingTempObject_walker,
context,
QTW_IGNORE_JOINALIASES);
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ if (isAnyTempNamespace(get_session_variable_namespace(p->paramvarid)))
+ return true;
+ }
+ }
return expression_tree_walker(node,
- isQueryUsingTempRelation_walker,
+ isQueryUsingTempObject_walker,
context);
}
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 576ac986ef9..a3fca34c7d7 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5351,12 +5351,16 @@ listVariables(const char *pattern, bool verbose)
" pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n"
" (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
" WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
- " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n",
+ " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
+ " CASE v.varxactendaction\n"
+ " WHEN 'd' THEN 'ON COMMIT DROP'\n"
+ " END as \"%s\"\n",
gettext_noop("Schema"),
gettext_noop("Name"),
gettext_noop("Type"),
gettext_noop("Collation"),
- gettext_noop("Owner"));
+ gettext_noop("Owner"),
+ gettext_noop("Transactional end action"));
if (verbose)
{
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index d9bb96ad318..86c2d5c3a66 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -3612,7 +3612,7 @@ match_previous_words(int pattern_id,
/* CREATE TABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete "CREATE TEMP/TEMPORARY" with the possible temp objects */
else if (TailMatches("CREATE", "TEMP|TEMPORARY"))
- COMPLETE_WITH("SEQUENCE", "TABLE", "VIEW");
+ COMPLETE_WITH("SEQUENCE", "TABLE", "VARIABLE", "VIEW");
/* Complete "CREATE UNLOGGED" with TABLE or SEQUENCE */
else if (TailMatches("CREATE", "UNLOGGED"))
COMPLETE_WITH("TABLE", "SEQUENCE");
@@ -3963,7 +3963,8 @@ match_previous_words(int pattern_id,
}
/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE VARIABLE <name> with AS */
- else if (TailMatches("CREATE", "VARIABLE", MatchAny))
+ else if (TailMatches("CREATE", "VARIABLE", MatchAny) ||
+ TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny))
COMPLETE_WITH("AS");
else if (TailMatches("VARIABLE", MatchAny, "AS"))
/* Complete CREATE VARIABLE <name> with AS types */
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 5b45be5afaf..0fc672bc2ba 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -56,6 +56,9 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* typmod for variable's type */
int32 vartypmod BKI_DEFAULT(-1);
+ /* action on transaction end */
+ char varxactendaction BKI_DEFAULT(n);
+
/* variable collation */
Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation);
@@ -68,6 +71,12 @@ CATALOG(pg_variable,9222,VariableRelationId)
#endif
} FormData_pg_variable;
+typedef enum VariableXactEndAction
+{
+ VARIABLE_XACTEND_NOOP = 'n', /* NOOP */
+ VARIABLE_XACTEND_DROP = 'd', /* ON COMMIT DROP */
+} VariableXactEndAction;
+
/* ----------------
* Form_pg_variable corresponds to a pointer to a tuple with
* the format of the pg_variable relation.
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index d3cc79b5608..4492bee6d69 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -21,7 +21,11 @@
#include "tcop/cmdtag.h"
#include "utils/queryenvironment.h"
-extern void SessionVariableDropPostprocess(Oid varid);
+extern void SessionVariableCreatePostprocess(Oid varid, char XactEndAction);
+extern void SessionVariableDropPostprocess(Oid varid, char XactEndAction);
+extern void AtPreEOXact_SessionVariables(bool isCommit);
+extern void AtEOSubXact_SessionVariables(bool isCommit, SubTransactionId mySubid,
+ SubTransactionId parentSubid);
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index d5f00cf3702..04d4a853a3c 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3535,6 +3535,7 @@ typedef struct CreateSessionVarStmt
TypeName *typeName; /* the type of variable */
CollateClause *collClause;
bool if_not_exists; /* do nothing if it already exists */
+ char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 98b9285a54b..34d051ec98a 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -52,7 +52,9 @@ typedef struct Alias
List *colnames; /* optional list of column aliases */
} Alias;
-/* What to do at commit time for temporary relations */
+/*
+ * What to do at commit time for temporary relations or session variables.
+ */
typedef enum OnCommitAction
{
ONCOMMIT_NOOP, /* No ON COMMIT clause (do nothing) */
diff --git a/src/include/parser/parse_relation.h b/src/include/parser/parse_relation.h
index 3ece5cd4eef..3529bfa5b30 100644
--- a/src/include/parser/parse_relation.h
+++ b/src/include/parser/parse_relation.h
@@ -127,6 +127,6 @@ extern int attnameAttNum(Relation rd, const char *attname, bool sysColOK);
extern const NameData *attnumAttName(Relation rd, int attid);
extern Oid attnumTypeId(Relation rd, int attid);
extern Oid attnumCollationId(Relation rd, int attid);
-extern bool isQueryUsingTempRelation(Query *query);
+extern bool isQueryUsingTempObject(Query *query);
#endif /* PARSE_RELATION_H */
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
index 0a5579dc7ce..a609797dc5d 100644
--- a/src/test/isolation/expected/session-variable.out
+++ b/src/test/isolation/expected/session-variable.out
@@ -86,10 +86,11 @@ myvar
step sr1: ROLLBACK;
-starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+starting permutation: create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
step create3: CREATE VARIABLE myvar3 AS text;
step let3: LET myvar3 = 'test';
step s3: BEGIN;
+step o_c_d: CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP;
step create4: CREATE VARIABLE myvar4 AS text;
step let4: LET myvar4 = 'test';
step drop4: DROP VARIABLE myvar4;
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
index c864fee4006..45e65d4085d 100644
--- a/src/test/isolation/specs/session-variable.spec
+++ b/src/test/isolation/specs/session-variable.spec
@@ -24,6 +24,7 @@ step create { CREATE VARIABLE myvar AS text; }
session s3
step s3 { BEGIN; }
step let3 { LET myvar3 = 'test'; }
+step o_c_d { CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP; }
step create4 { CREATE VARIABLE myvar4 AS text; }
step let4 { LET myvar4 = 'test'; }
step drop4 { DROP VARIABLE myvar4; }
@@ -47,4 +48,4 @@ permutation let val dbg drop create dbg val
# calling the dbg step after the concurrent drop
permutation let val s1 dbg drop create dbg val sr1
# test for DISCARD ALL when all internal queues have actions registered
-permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+permutation create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 0c48fdfaf61..3ddbcc7cc2a 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6020,20 +6020,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Access privileges | Description
---------+------+-------------------+-----------+------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Access privileges | Description
---------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6501,9 +6501,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner
---------+------+------+-----------+-------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action
+--------+------+------+-----------+-------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6676,9 +6676,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner
---------+------+------+-----------+-------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action
+--------+------+------+-----------+-------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6815,9 +6815,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner
---------+------+------+-----------+-------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action
+--------+------+------+-----------+-------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index cef0d5ab3ca..2621591a16a 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2235,3 +2235,123 @@ SELECT var1;
DEALLOCATE p1;
DROP VARIABLE var1;
+-- temporary variables
+CREATE TEMP VARIABLE var1 AS int;
+-- this view should be temporary
+CREATE VIEW var_test_view AS SELECT var1;
+NOTICE: view "var_test_view" will be a temporary view
+DROP VARIABLE var1 CASCADE;
+NOTICE: drop cascades to view var_test_view
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+ROLLBACK;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ ROLLBACK TO s1;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 9f212e29835..610261a617f 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1312,6 +1312,7 @@ BEGIN;
DROP VARIABLE var1;
SELECT var2;
ROLLBACK;
+
-- should be ok
SELECT var1;
@@ -1552,3 +1553,68 @@ SELECT var1;
DEALLOCATE p1;
DROP VARIABLE var1;
+
+-- temporary variables
+CREATE TEMP VARIABLE var1 AS int;
+-- this view should be temporary
+CREATE VIEW var_test_view AS SELECT var1;
+
+DROP VARIABLE var1 CASCADE;
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+ROLLBACK;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+ROLLBACK;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ ROLLBACK TO s1;
+ SELECT var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 95c7a892f97..a2147df28b3 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2818,6 +2818,7 @@ SupportRequestWFuncMonotonic
SVariable
SVariableData
SVariableState
+SVariableXActDropItem
Syn
SyncOps
SyncRepConfigData
--
2.48.1
[text/x-patch] v20250212-0011-PREPARE-LET-support.patch (7.4K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/14-v20250212-0011-PREPARE-LET-support.patch)
download | inline diff:
From e102e37c44bd2cfc9d37e418b3a58a75afe4e0ea Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 09:44:58 +0100
Subject: [PATCH 11/22] PREPARE LET support
In current code base it requires just small changes in parser. It is nice
to have to have possibility to use prepared LET statements mainly due reduction
of security risks (SQL injection), and implementation is almost cheap.
Explicit preparing is not necessity for support of LET statements in PL, because
PL uses SPI for query execution, but it is nice to have this possibility (completenees, ...)
---
doc/src/sgml/ref/prepare.sgml | 4 +-
src/backend/parser/gram.y | 3 +-
src/backend/parser/parse_cte.c | 7 ++
src/bin/psql/tab-complete.in.c | 4 +-
.../regress/expected/session_variables.out | 81 ++++++++++++++++++-
src/test/regress/sql/session_variables.sql | 57 +++++++++++++
6 files changed, 149 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/ref/prepare.sgml b/doc/src/sgml/ref/prepare.sgml
index 8ee9439f611..45d72b1d52b 100644
--- a/doc/src/sgml/ref/prepare.sgml
+++ b/doc/src/sgml/ref/prepare.sgml
@@ -116,8 +116,8 @@ PREPARE <replaceable class="parameter">name</replaceable> [ ( <replaceable class
<listitem>
<para>
Any <command>SELECT</command>, <command>INSERT</command>, <command>UPDATE</command>,
- <command>DELETE</command>, <command>MERGE</command>, or <command>VALUES</command>
- statement.
+ <command>DELETE</command>, <command>MERGE</command>, <command>VALUES</command>,
+ or <command>LET</command> statement.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 41d2b35b7c3..b5bd1093572 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -12198,7 +12198,8 @@ PreparableStmt:
| InsertStmt
| UpdateStmt
| DeleteStmt
- | MergeStmt /* by default all are $$=$1 */
+ | MergeStmt
+ | LetStmt /* by default all are $$=$1 */
;
/*****************************************************************************
diff --git a/src/backend/parser/parse_cte.c b/src/backend/parser/parse_cte.c
index 79673621c9b..c62761e4eae 100644
--- a/src/backend/parser/parse_cte.c
+++ b/src/backend/parser/parse_cte.c
@@ -126,6 +126,13 @@ transformWithClause(ParseState *pstate, WithClause *withClause)
CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
ListCell *rest;
+ /* LET is allowed by parser, but not supported. Reject for now */
+ if (IsA(cte->ctequery, LetStmt))
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("LET not supported in WITH query"),
+ parser_errposition(pstate, cte->location));
+
for_each_cell(rest, withClause->ctes, lnext(withClause->ctes, lc))
{
CommonTableExpr *cte2 = (CommonTableExpr *) lfirst(rest);
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 0cc8eb56bb4..d9bb96ad318 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4664,9 +4664,9 @@ match_previous_words(int pattern_id,
else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES"))
COMPLETE_WITH("(");
-/* LET */
+/* LET, EXPLAIN LET, PREPARE LET */
/* If prev. word is LET suggest a list of variables */
- else if (Matches("LET"))
+ else if (TailMatches("LET"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
/* Complete LET <variable> with "=" */
else if (TailMatches("LET", MatchAny))
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 15ae6eafafc..cef0d5ab3ca 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -940,9 +940,9 @@ DROP VARIABLE var1, var2;
-- the LET statement should be disallowed in CTE
CREATE VARIABLE var1 AS int;
WITH x AS (LET var1 = 100) SELECT * FROM x;
-ERROR: syntax error at or near "LET"
+ERROR: LET not supported in WITH query
LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x;
- ^
+ ^
-- should be ok
LET var1 = generate_series(1, 1);
-- should fail
@@ -2156,5 +2156,82 @@ SELECT var1;
10
(1 row)
+SET plan_cache_mode TO force_generic_plan;
+PREPARE p1 AS LET var1 = (SELECT count(*) FROM var_tab_test_table);
+LET var1 = NULL;
+EXPLAIN (COSTS OFF) EXECUTE p1;
+ QUERY PLAN
+----------------------------------------------
+ SET SESSION VARIABLE
+ Result
+ InitPlan 1
+ -> Aggregate
+ -> Seq Scan on var_tab_test_table
+(5 rows)
+
+-- should be NULL
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) EXECUTE p1;
+ QUERY PLAN
+-----------------------------------------------------------------------
+ SET SESSION VARIABLE
+ Result (actual rows=1 loops=1)
+ InitPlan 1
+ -> Aggregate (actual rows=1 loops=1)
+ -> Seq Scan on var_tab_test_table (actual rows=10 loops=1)
+(5 rows)
+
+-- should be 10
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SET plan_cache_mode TO DEFAULT;
+DEALLOCATE p1;
DROP VARIABLE var1;
DROP TABLE var_tab_test_table;
+CREATE VARIABLE var1 numeric;
+SET plan_cache_mode TO force_generic_plan;
+PREPARE p1(numeric) AS LET var1 = $1;
+PREPARE p2 AS SELECT var1;
+EXECUTE p1(pi() + 100);
+EXECUTE p2;
+ var1
+-----------------
+ 103.14159265359
+(1 row)
+
+-- prepared plan cache invalidation test
+DROP VARIABLE var1;
+CREATE VARIABLE var1 numeric;
+-- should be NULL
+EXECUTE p2;
+ var1
+------
+
+(1 row)
+
+DEALLOCATE p1;
+DEALLOCATE p2;
+DROP VARIABLE var1;
+SET plan_cache_mode TO force_generic_plan;
+CREATE VARIABLE var1 numeric[];
+PREPARE p1(int, numeric) AS LET var1[$1] = $2;
+LET var1 = '{}'::numeric[];
+EXECUTE p1(1, 10.2);
+EXECUTE p1(2, 10.3);
+SELECT var1;
+ var1
+-------------
+ {10.2,10.3}
+(1 row)
+
+DEALLOCATE p1;
+DROP VARIABLE var1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 2a9e244a995..9f212e29835 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1493,5 +1493,62 @@ EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) LET var1 = (S
-- should be 10
SELECT var1;
+SET plan_cache_mode TO force_generic_plan;
+
+PREPARE p1 AS LET var1 = (SELECT count(*) FROM var_tab_test_table);
+
+LET var1 = NULL;
+
+EXPLAIN (COSTS OFF) EXECUTE p1;
+
+-- should be NULL
+SELECT var1;
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) EXECUTE p1;
+
+-- should be 10
+SELECT var1;
+
+SET plan_cache_mode TO DEFAULT;
+
+DEALLOCATE p1;
+
DROP VARIABLE var1;
DROP TABLE var_tab_test_table;
+
+CREATE VARIABLE var1 numeric;
+
+SET plan_cache_mode TO force_generic_plan;
+
+PREPARE p1(numeric) AS LET var1 = $1;
+PREPARE p2 AS SELECT var1;
+
+EXECUTE p1(pi() + 100);
+EXECUTE p2;
+
+-- prepared plan cache invalidation test
+DROP VARIABLE var1;
+CREATE VARIABLE var1 numeric;
+
+-- should be NULL
+EXECUTE p2;
+
+DEALLOCATE p1;
+DEALLOCATE p2;
+
+DROP VARIABLE var1;
+
+SET plan_cache_mode TO force_generic_plan;
+
+CREATE VARIABLE var1 numeric[];
+
+PREPARE p1(int, numeric) AS LET var1[$1] = $2;
+
+LET var1 = '{}'::numeric[];
+EXECUTE p1(1, 10.2);
+EXECUTE p1(2, 10.3);
+
+SELECT var1;
+
+DEALLOCATE p1;
+DROP VARIABLE var1;
--
2.48.1
[text/x-patch] v20250212-0010-EXPLAIN-LET-support.patch (8.2K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/15-v20250212-0010-EXPLAIN-LET-support.patch)
download | inline diff:
From 1b047276f83ecfb124ac8e074ee4e9e818927a0b Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 21 May 2024 18:28:07 +0200
Subject: [PATCH 10/22] EXPLAIN LET support
Enhancing ExplainOnePlan is necessary to be EXPLAIN ANALYZE LET fully workable.
In this case we want to be result of query or expression written to target variable.
---
doc/src/sgml/ref/explain.sgml | 3 +-
src/backend/commands/explain.c | 31 ++++++++++++--
src/backend/commands/prepare.c | 5 ++-
src/backend/parser/gram.y | 3 +-
src/include/commands/explain.h | 3 +-
.../regress/expected/session_variables.out | 40 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 21 ++++++++++
7 files changed, 97 insertions(+), 9 deletions(-)
diff --git a/doc/src/sgml/ref/explain.sgml b/doc/src/sgml/ref/explain.sgml
index 6361a14e65d..4292615b447 100644
--- a/doc/src/sgml/ref/explain.sgml
+++ b/doc/src/sgml/ref/explain.sgml
@@ -98,7 +98,8 @@ EXPLAIN [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] <rep
<command>INSERT</command>, <command>UPDATE</command>,
<command>DELETE</command>, <command>MERGE</command>,
<command>CREATE TABLE AS</command>,
- or <command>EXECUTE</command> statement
+ <command>EXECUTE</command>,
+ or <command>LET</command> statement
without letting the command affect your data, use this approach:
<programlisting>
BEGIN;
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index c24e66f82e1..a608f81ef4f 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -18,6 +18,7 @@
#include "commands/createas.h"
#include "commands/defrem.h"
#include "commands/prepare.h"
+#include "executor/svariableReceiver.h"
#include "foreign/fdwapi.h"
#include "jit/jit.h"
#include "libpq/pqformat.h"
@@ -519,8 +520,9 @@ standard_ExplainOneQuery(Query *query, int cursorOptions,
}
/* run it (if needed) and produce output */
- ExplainOnePlan(plan, into, es, queryString, params, queryEnv,
- &planduration, (es->buffers ? &bufusage : NULL),
+ ExplainOnePlan(plan, into, query->resultVariable, es, queryString,
+ params, queryEnv, &planduration,
+ (es->buffers ? &bufusage : NULL),
es->memory ? &mem_counters : NULL);
}
@@ -618,6 +620,25 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
else
ExplainDummyGroup("Notify", NULL, es);
}
+ else if (IsA(utilityStmt, LetStmt))
+ {
+ LetStmt *letstmt = (LetStmt *) utilityStmt;
+ List *rewritten;
+ Query *query;
+
+ if (es->format == EXPLAIN_FORMAT_TEXT)
+ appendStringInfoString(es->str, "SET SESSION VARIABLE\n");
+ else
+ ExplainDummyGroup("Set Session Variable", NULL, es);
+
+ rewritten = QueryRewrite(castNode(Query, copyObject(letstmt->query)));
+
+ Assert(list_length(rewritten) == 1);
+ query = linitial_node(Query, rewritten);
+ ExplainOneQuery(query,
+ CURSOR_OPT_PARALLEL_OK, NULL, es,
+ pstate, params);
+ }
else
{
if (es->format == EXPLAIN_FORMAT_TEXT)
@@ -641,8 +662,8 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
* to call it.
*/
void
-ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
- const char *queryString, ParamListInfo params,
+ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, Oid targetvar,
+ ExplainState *es, const char *queryString, ParamListInfo params,
QueryEnvironment *queryEnv, const instr_time *planduration,
const BufferUsage *bufusage,
const MemoryContextCounters *mem_counters)
@@ -691,6 +712,8 @@ ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
*/
if (into)
dest = CreateIntoRelDestReceiver(into);
+ else if (OidIsValid(targetvar))
+ dest = CreateVariableDestReceiver(targetvar);
else if (es->serialize != EXPLAIN_SERIALIZE_NONE)
dest = CreateExplainSerializeDestReceiver(es);
else
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 902b022f9c7..4ea2bfea4ea 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -664,8 +664,9 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
PlannedStmt *pstmt = lfirst_node(PlannedStmt, p);
if (pstmt->commandType != CMD_UTILITY)
- ExplainOnePlan(pstmt, into, es, query_string, paramLI, pstate->p_queryEnv,
- &planduration, (es->buffers ? &bufusage : NULL),
+ ExplainOnePlan(pstmt, into, InvalidOid, es, query_string, paramLI,
+ pstate->p_queryEnv, &planduration,
+ (es->buffers ? &bufusage : NULL),
es->memory ? &mem_counters : NULL);
else
ExplainOneUtility(pstmt->utilityStmt, into, es, pstate, paramLI);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index a8c098c3d5a..41d2b35b7c3 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -12167,7 +12167,8 @@ ExplainableStmt:
| CreateAsStmt
| CreateMatViewStmt
| RefreshMatViewStmt
- | ExecuteStmt /* by default all are $$=$1 */
+ | ExecuteStmt
+ | LetStmt /* by default all are $$=$1 */
;
/*****************************************************************************
diff --git a/src/include/commands/explain.h b/src/include/commands/explain.h
index ea7419951f4..de21fe97d01 100644
--- a/src/include/commands/explain.h
+++ b/src/include/commands/explain.h
@@ -103,7 +103,8 @@ extern void ExplainOneUtility(Node *utilityStmt, IntoClause *into,
ExplainState *es, ParseState *pstate,
ParamListInfo params);
-extern void ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into,
+extern void ExplainOnePlan(PlannedStmt *plannedstmt,
+ IntoClause *into, Oid targetvar,
ExplainState *es, const char *queryString,
ParamListInfo params, QueryEnvironment *queryEnv,
const instr_time *planduration,
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index eda4eb20798..15ae6eafafc 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2118,3 +2118,43 @@ NOTICE: 20 t
SET session_variables_visibility TO DEFAULT;
DROP VARIABLE var1;
DROP TABLE vartest_tab1;
+CREATE VARIABLE var1 bigint;
+CREATE TABLE var_tab_test_table(a int);
+INSERT INTO var_tab_test_table SELECT * FROM generate_series(1,10);
+VACUUM ANALYZE var_tab_test_table;
+EXPLAIN (COSTS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+ QUERY PLAN
+----------------------------------------------
+ SET SESSION VARIABLE
+ Result
+ InitPlan 1
+ -> Aggregate
+ -> Seq Scan on var_tab_test_table
+(5 rows)
+
+-- should be NULL
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+ QUERY PLAN
+-----------------------------------------------------------------------
+ SET SESSION VARIABLE
+ Result (actual rows=1 loops=1)
+ InitPlan 1
+ -> Aggregate (actual rows=1 loops=1)
+ -> Seq Scan on var_tab_test_table (actual rows=10 loops=1)
+(5 rows)
+
+-- should be 10
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1;
+DROP TABLE var_tab_test_table;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 08d669f86d2..2a9e244a995 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1474,3 +1474,24 @@ SET session_variables_visibility TO DEFAULT;
DROP VARIABLE var1;
DROP TABLE vartest_tab1;
+
+CREATE VARIABLE var1 bigint;
+
+CREATE TABLE var_tab_test_table(a int);
+
+INSERT INTO var_tab_test_table SELECT * FROM generate_series(1,10);
+
+VACUUM ANALYZE var_tab_test_table;
+
+EXPLAIN (COSTS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+
+-- should be NULL
+SELECT var1;
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+
+-- should be 10
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP TABLE var_tab_test_table;
--
2.48.1
[text/x-patch] v20250212-0009-possibility-to-control-implicit-visibility-of-sessio.patch (14.9K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/16-v20250212-0009-possibility-to-control-implicit-visibility-of-sessio.patch)
download | inline diff:
From aa0f9e325dbda96661e68cd8744a6c8c794de0d1 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 13 Dec 2024 06:28:45 +0100
Subject: [PATCH 09/22] possibility to control implicit visibility of session
variables.
Fenced variable is visible everywhere. Unfenced variable can
be visible everywhere (when session_variables_visibility is everywhere),
or can be visible nowhere (session_variables_visibility is nowhere)
or can be visible inside stored procedures (session_variables_visibility is PL).
---
doc/src/sgml/config.sgml | 53 +++++++++++
doc/src/sgml/ddl.sgml | 3 +-
src/backend/parser/parse_expr.c | 30 ++++++-
src/backend/parser/parse_node.c | 1 +
src/backend/utils/misc/guc_tables.c | 18 ++++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/parser/parse_expr.h | 14 +++
src/include/parser/parse_node.h | 3 +
src/pl/plpgsql/src/pl_comp.c | 1 +
.../regress/expected/session_variables.out | 90 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 73 +++++++++++++++
11 files changed, 284 insertions(+), 3 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 1500226e9b5..257aa903629 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11062,6 +11062,59 @@ SELECT a, VARIABLE(b) FROM foo;
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-visibility" xreflabel="session_variables_visibility">
+ <term><varname>session_variables_visibility</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_visibility</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ This option specify, where the session variables are visible implicitly
+ without using variable fencing. The default is <literal>everywhere</literal>.
+ The allowed values of <varname>session_variables_visibility</varname> are
+ <literal>everywhere</literal> (allows using session variables without
+ variables's fences always), <literal>nowhere</literal> (requires variable's
+ fencing always) or <literal>pl</literal> (the variable fencing is optional
+ in stored procedures).
+<programlisting>
+SET session_variables_visibility TO 'pl';
+CREATE VARIABLE a int;
+
+LET a = 10;
+DO $$
+BEGIN
+ RAISE NOTICE 'a = %', a;
+END;
+$$;
+
+SELECT a;
+SELECT VARIABLE(s);
+</programlisting>
+
+<screen>
+NOTICE: a = 10
+
+ERROR: column "a" does not exist
+LINE 1: SELECT a;
+ ^
+
+SELECT variable(a);
+ a
+----
+ 10
+(1 row)
+</screen>
+ </para>
+
+ <para>
+ When you afraid about unwanted usage of session variables, set
+ this feature to <literal>nowhere</literal> or minimaly to
+ <literal>pl</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4e8e7c6a42a..748219b3804 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5469,7 +5469,8 @@ SELECT VARIABLE(current_user_id);
When there is a risk of possible collisions between variable identifiers
and column names, then using variable fence syntax can be recommended.
Usage session variable without variable fence can be detected by
- warning <xref linkend="guc-session-variables-use-fence-warning-guard"/>.
+ warning <xref linkend="guc-session-variables-use-fence-warning-guard"/>
+ or controlled by <xref linkend="guc-session-variables-visibility"/>.
</para>
</sect1>
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index dd03b1f14db..bc751b4a441 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -47,7 +47,7 @@
bool Transform_null_equals = false;
bool session_variables_ambiguity_warning = false;
bool session_variables_use_fence_warning_guard = false;
-
+int session_variables_visibility = SESSIONVARIABLE_VISIBILITY_EVERYWHERE;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
static Node *transformParamRef(ParseState *pstate, ParamRef *pref);
@@ -115,6 +115,7 @@ static Node *make_nulltest_from_distinct(ParseState *pstate,
static Node *makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
char *attrname, bool fenced, int location);
+static bool session_variables_are_visible(ParseState *pstate);
/*
@@ -949,8 +950,14 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
* need to identify session variables in such a context, but identifying
* them allows us to raise meaningful error messages like "you cannot use
* session variables here".
+ *
+ * The visibility of session variables can be controlled by GUG
+ * session_variables_visibility. Don't try to detect session variables
+ * when are in context, where are not visible and variable fence are
+ * required.
*/
- if (expr_kind_allows_session_variables(pstate->p_expr_kind))
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind) &&
+ session_variables_are_visible(pstate))
{
Oid varid = InvalidOid;
char *attrname = NULL;
@@ -1225,6 +1232,25 @@ transformVariableFence(ParseState *pstate, VariableFence *vf)
return result;
}
+/* returns true, when session variables are visible without variable fence */
+static bool
+session_variables_are_visible(ParseState *pstate)
+{
+ switch (session_variables_visibility)
+ {
+ case SESSIONVARIABLE_VISIBILITY_NOWHERE:
+ return false;
+
+ case SESSIONVARIABLE_VISIBILITY_EVERYWHERE:
+ return true;
+
+ case SESSIONVARIABLE_VISIBILITY_PL:
+ return pstate->p_is_PL;
+ }
+
+ return false;
+}
+
/* Test whether an a_expr is a plain NULL constant or not */
static bool
exprIsNullConstant(Node *arg)
diff --git a/src/backend/parser/parse_node.c b/src/backend/parser/parse_node.c
index d6feb16aef3..4e337c3af82 100644
--- a/src/backend/parser/parse_node.c
+++ b/src/backend/parser/parse_node.c
@@ -51,6 +51,7 @@ make_parsestate(ParseState *parentParseState)
if (parentParseState)
{
pstate->p_sourcetext = parentParseState->p_sourcetext;
+ pstate->p_is_PL = parentParseState->p_is_PL;
/* all hooks are copied from parent */
pstate->p_pre_columnref_hook = parentParseState->p_pre_columnref_hook;
pstate->p_post_columnref_hook = parentParseState->p_post_columnref_hook;
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 237b1212e7a..3886d199cea 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -423,6 +423,13 @@ static const struct config_enum_entry debug_logical_replication_streaming_option
{NULL, 0, false}
};
+static const struct config_enum_entry session_variables_visibility_options[] = {
+ {"nowhere", SESSIONVARIABLE_VISIBILITY_NOWHERE, false},
+ {"everywhere", SESSIONVARIABLE_VISIBILITY_EVERYWHERE, false},
+ {"pl", SESSIONVARIABLE_VISIBILITY_PL, false},
+ {NULL, 0, false}
+};
+
StaticAssertDecl(lengthof(ssl_protocol_versions_info) == (PG_TLS1_3_VERSION + 2),
"array length mismatch");
@@ -5283,6 +5290,17 @@ struct config_enum ConfigureNamesEnum[] =
NULL, NULL, NULL
},
+ {
+ {"session_variables_visibility", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Chooses the context where session variables can be visible without variable fence."),
+ NULL
+ },
+ &session_variables_visibility,
+ SESSIONVARIABLE_VISIBILITY_EVERYWHERE, session_variables_visibility_options,
+ NULL, NULL, NULL
+ },
+
+
/* End-of-list marker */
{
{NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL, NULL
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index b84e8659ae1..46b05ee081a 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -737,6 +737,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#session_replication_role = 'origin'
#session_variables_ambiguity_warning = off
#session_variables_use_fence_warning_guard = off
+#session_variables_visibility = 'everywhere'
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index 5bde43758d1..e2f8d832242 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -15,10 +15,24 @@
#include "parser/parse_node.h"
+/*
+ * Specify the dynamic context where variable fence is required
+ */
+typedef enum SessionVariablesVisibility
+{
+ /* Variable fencing is required everywhere */
+ SESSIONVARIABLE_VISIBILITY_NOWHERE,
+ /* Variable fencing is required nowhere */
+ SESSIONVARIABLE_VISIBILITY_EVERYWHERE,
+ /* Variable fencing is required outside PL */
+ SESSIONVARIABLE_VISIBILITY_PL,
+} SessionVariablesVisibility;
+
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
extern PGDLLIMPORT bool session_variables_ambiguity_warning;
extern PGDLLIMPORT bool session_variables_use_fence_warning_guard;
+extern PGDLLIMPORT int session_variables_visibility;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 0b7b69a4159..bb6b9251083 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -248,6 +248,9 @@ struct ParseState
bool p_hasModifyingCTE;
bool p_hasSessionVariables;
+ /* true, when the query is executed from PL environment */
+ bool p_is_PL;
+
Node *p_last_srf; /* most recent set-returning func/op found */
/*
diff --git a/src/pl/plpgsql/src/pl_comp.c b/src/pl/plpgsql/src/pl_comp.c
index f36a244140e..a5749d902e1 100644
--- a/src/pl/plpgsql/src/pl_comp.c
+++ b/src/pl/plpgsql/src/pl_comp.c
@@ -1101,6 +1101,7 @@ plpgsql_parser_setup(struct ParseState *pstate, PLpgSQL_expr *expr)
pstate->p_paramref_hook = plpgsql_param_ref;
/* no need to use p_coerce_param_hook */
pstate->p_ref_hook_state = expr;
+ pstate->p_is_PL = true;
}
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 9ac08a14e0b..eda4eb20798 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2028,3 +2028,93 @@ DROP SCHEMA testvar;
SET session_variables_ambiguity_warning TO DEFAULT;
SET session_variables_use_fence_warning_guard TO DEFAULT;
SET search_path TO DEFAULT;
+-- test session_variables_visibility
+CREATE VARIABLE var1 AS int;
+CREATE TABLE vartest_tab1(a int);
+LET var1 = 20;
+INSERT INTO vartest_tab1 VALUES(20);
+SET session_variables_visibility TO 'everywhere';
+-- should be ok
+SELECT var1, VARIABLE(var1);
+ var1 | var1
+------+------
+ 20 | 20
+(1 row)
+
+DO $$
+DECLARE t int;
+BEGIN
+ SELECT a FROM vartest_tab1 WHERE a = var1 INTO t;
+ RAISE NOTICE '% %', var1, var1 = t;
+ SELECT a FROM vartest_tab1 WHERE a = VARIABLE(var1) INTO t;
+ RAISE NOTICE '% %', VARIABLE(var1), VARIABLE(var1) = t;
+END;
+$$;
+NOTICE: 20 t
+NOTICE: 20 t
+SET session_variables_visibility TO 'nowhere';
+-- should fail
+SELECT var1, VARIABLE(var1);
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1, VARIABLE(var1);
+ ^
+-- should fail
+DO $$
+DECLARE t int;
+BEGIN
+ SELECT a FROM vartest_tab1 WHERE a = var1 INTO t;
+END;
+$$;
+ERROR: column "var1" does not exist
+LINE 1: SELECT a FROM vartest_tab1 WHERE a = var1
+ ^
+QUERY: SELECT a FROM vartest_tab1 WHERE a = var1
+CONTEXT: PL/pgSQL function inline_code_block line 4 at SQL statement
+-- should fail
+DO $$
+DECLARE t int DEFAULT 20;
+BEGIN
+ RAISE NOTICE '% %', var1, var1 = t;
+END;
+$$;
+ERROR: column "var1" does not exist
+LINE 1: var1
+ ^
+QUERY: var1
+CONTEXT: PL/pgSQL function inline_code_block line 4 at RAISE
+-- should be ok
+SELECT VARIABLE(var1), VARIABLE(var1);
+ var1 | var1
+------+------
+ 20 | 20
+(1 row)
+
+DO $$
+DECLARE t int;
+BEGIN
+ SELECT a FROM vartest_tab1 WHERE a = VARIABLE(var1) INTO t;
+ RAISE NOTICE '% %', VARIABLE(var1), VARIABLE(var1) = t;
+END;
+$$;
+NOTICE: 20 t
+SET session_variables_visibility TO 'pl';
+-- should fail
+SELECT var1, VARIABLE(var1);
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1, VARIABLE(var1);
+ ^
+-- should be ok
+DO $$
+DECLARE t int;
+BEGIN
+ SELECT a FROM vartest_tab1 WHERE a = var1 INTO t;
+ RAISE NOTICE '% %', var1, var1 = t;
+ SELECT a FROM vartest_tab1 WHERE a = VARIABLE(var1) INTO t;
+ RAISE NOTICE '% %', VARIABLE(var1), VARIABLE(var1) = t;
+END;
+$$;
+NOTICE: 20 t
+NOTICE: 20 t
+SET session_variables_visibility TO DEFAULT;
+DROP VARIABLE var1;
+DROP TABLE vartest_tab1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index c5420183d94..08d669f86d2 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1401,3 +1401,76 @@ DROP SCHEMA testvar;
SET session_variables_ambiguity_warning TO DEFAULT;
SET session_variables_use_fence_warning_guard TO DEFAULT;
SET search_path TO DEFAULT;
+
+-- test session_variables_visibility
+CREATE VARIABLE var1 AS int;
+CREATE TABLE vartest_tab1(a int);
+
+LET var1 = 20;
+INSERT INTO vartest_tab1 VALUES(20);
+
+SET session_variables_visibility TO 'everywhere';
+
+-- should be ok
+SELECT var1, VARIABLE(var1);
+DO $$
+DECLARE t int;
+BEGIN
+ SELECT a FROM vartest_tab1 WHERE a = var1 INTO t;
+ RAISE NOTICE '% %', var1, var1 = t;
+ SELECT a FROM vartest_tab1 WHERE a = VARIABLE(var1) INTO t;
+ RAISE NOTICE '% %', VARIABLE(var1), VARIABLE(var1) = t;
+END;
+$$;
+
+SET session_variables_visibility TO 'nowhere';
+
+-- should fail
+SELECT var1, VARIABLE(var1);
+
+-- should fail
+DO $$
+DECLARE t int;
+BEGIN
+ SELECT a FROM vartest_tab1 WHERE a = var1 INTO t;
+END;
+$$;
+
+-- should fail
+DO $$
+DECLARE t int DEFAULT 20;
+BEGIN
+ RAISE NOTICE '% %', var1, var1 = t;
+END;
+$$;
+
+-- should be ok
+SELECT VARIABLE(var1), VARIABLE(var1);
+DO $$
+DECLARE t int;
+BEGIN
+ SELECT a FROM vartest_tab1 WHERE a = VARIABLE(var1) INTO t;
+ RAISE NOTICE '% %', VARIABLE(var1), VARIABLE(var1) = t;
+END;
+$$;
+
+SET session_variables_visibility TO 'pl';
+
+-- should fail
+SELECT var1, VARIABLE(var1);
+
+-- should be ok
+DO $$
+DECLARE t int;
+BEGIN
+ SELECT a FROM vartest_tab1 WHERE a = var1 INTO t;
+ RAISE NOTICE '% %', var1, var1 = t;
+ SELECT a FROM vartest_tab1 WHERE a = VARIABLE(var1) INTO t;
+ RAISE NOTICE '% %', VARIABLE(var1), VARIABLE(var1) = t;
+END;
+$$;
+
+SET session_variables_visibility TO DEFAULT;
+
+DROP VARIABLE var1;
+DROP TABLE vartest_tab1;
--
2.48.1
[text/x-patch] v20250212-0008-variable-fence-syntax-support-and-variable-fence-usa.patch (19.5K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/17-v20250212-0008-variable-fence-syntax-support-and-variable-fence-usa.patch)
download | inline diff:
From 4f3eaca0fbc5efb0e3cbf4001f2f2b7aa547cad1 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 19 Nov 2024 08:14:53 +0100
Subject: [PATCH 08/22] variable fence syntax support and variable fence usage
guard support
this patch introduces a concept of variable fence - syntax for variable
reference `VARIABLE(varname)` that is not in collision with column reference.
When variable fence usage guard warning is active, then usage variable
without variable fence in the case, where there can be column references,
the the warning is raised.
initial implementation of variable fence
---
doc/src/sgml/config.sgml | 65 ++++++++++++++++
doc/src/sgml/ddl.sgml | 15 ++++
src/backend/nodes/nodeFuncs.c | 6 ++
src/backend/parser/gram.y | 28 ++++++-
src/backend/parser/parse_expr.c | 74 ++++++++++++++++++-
src/backend/parser/parse_target.c | 7 ++
src/backend/utils/adt/ruleutils.c | 12 ++-
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/nodes/parsenodes.h | 10 +++
src/include/nodes/primnodes.h | 2 +
src/include/parser/parse_expr.h | 1 +
.../regress/expected/session_variables.out | 59 +++++++++++++++
src/test/regress/sql/session_variables.sql | 41 ++++++++++
14 files changed, 323 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 61de7059d75..1500226e9b5 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -10997,6 +10997,71 @@ DETAIL: Session variables can be shadowed by columns, routine's variables and r
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-use-fence-warning-guard" xreflabel="session_variables_use_fence_warning_guard">
+ <term><varname>session_variables_use_fence_warning_guard</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_use_fence_warning_guard</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when a session variable identifier is used
+ inside a query without variable fence. The default is <literal>off</literal>.
+ The warning is raised only when variable is used in places, where an
+ collisions with column names is possible.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE b int;
+LET b = 100;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_use_fence_warning_guard TO on;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "b" is not used inside variable fence
+LINE 1: SELECT a, b FROM foo;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SELECT a, VARIABLE(b) FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+ </para>
+
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. Unless another collision resolution technique is used
+ (dedicated schema or using prefixes like <literal>_</literal>),
+ the use of variable fence syntax is strongly recommended, and this
+ warning should be enabled.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 96912aaa436..4e8e7c6a42a 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5456,6 +5456,21 @@ SELECT name FROM foo;
<literal>schema.variable</literal>. It is strongly recommended to rename
shadowed variables or use qualified names always.
</para>
+
+ <para><firstterm>Variable fence</firstterm> is special syntax for session
+ variable identifier. Only name or qualified name can be used inside the
+ variable fence, and this name is used as only session variable identifier.
+<programlisting>
+SELECT VARIABLE(current_user_id);
+</programlisting>
+ </para>
+
+ <para>
+ When there is a risk of possible collisions between variable identifiers
+ and column names, then using variable fence syntax can be recommended.
+ Usage session variable without variable fence can be detected by
+ warning <xref linkend="guc-session-variables-use-fence-warning-guard"/>.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d8fc3d9fa69..575365eefcd 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1673,6 +1673,9 @@ exprLocation(const Node *expr)
case T_ParamRef:
loc = ((const ParamRef *) expr)->location;
break;
+ case T_VariableFence:
+ loc = ((const VariableFence *) expr)->location;
+ break;
case T_A_Const:
loc = ((const A_Const *) expr)->location;
break;
@@ -4715,6 +4718,9 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_VariableFence:
+ /* we assume the fields contain nothing interesting */
+ break;
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 77d9246f4a1..a8c098c3d5a 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -525,7 +525,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <node> def_arg columnElem where_clause where_or_current_clause
a_expr b_expr c_expr AexprConst indirection_el opt_slice_bound
columnref in_expr having_clause func_table xmltable array_expr
- OptWhereClause operator_def_arg
+ OptWhereClause operator_def_arg variable_fence
%type <list> opt_column_and_period_list
%type <list> rowsfrom_item rowsfrom_list opt_col_def_list
%type <boolean> opt_ordinality opt_without_overlaps
@@ -882,7 +882,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
*/
%nonassoc UNBOUNDED NESTED /* ideally would have same precedence as IDENT */
%nonassoc IDENT PARTITION RANGE ROWS GROUPS PRECEDING FOLLOWING CUBE ROLLUP
- SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH
+ SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH VARIABLE
%left Op OPERATOR /* multi-character ops and user-defined operators */
%left '+' '-'
%left '*' '/' '%'
@@ -15668,6 +15668,19 @@ c_expr: columnref { $$ = $1; }
else
$$ = $2;
}
+ | variable_fence opt_indirection
+ {
+ if ($2)
+ {
+ A_Indirection *n = makeNode(A_Indirection);
+
+ n->arg = (Node *) $1;
+ n->indirection = check_indirection($2, yyscanner);
+ $$ = (Node *) n;
+ }
+ else
+ $$ = $1;
+ }
| case_expr
{ $$ = $1; }
| func_expr
@@ -17054,6 +17067,17 @@ case_arg: a_expr { $$ = $1; }
| /*EMPTY*/ { $$ = NULL; }
;
+variable_fence:
+ VARIABLE '(' any_name ')'
+ {
+ VariableFence *vf = makeNode(VariableFence);
+
+ vf->varname = $3;
+ vf->location = @3;
+ $$ = (Node *) vf;
+ }
+ ;
+
columnref: ColId
{
$$ = makeColumnRef($1, NIL, @1, yyscanner);
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 63f1732f69e..dd03b1f14db 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -46,6 +46,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
bool session_variables_ambiguity_warning = false;
+bool session_variables_use_fence_warning_guard = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -81,6 +82,7 @@ static Node *transformWholeRowRef(ParseState *pstate,
static Node *transformIndirection(ParseState *pstate, A_Indirection *ind);
static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
static Node *transformCollateClause(ParseState *pstate, CollateClause *c);
+static Node *transformVariableFence(ParseState *pstate, VariableFence *vf);
static Node *transformJsonObjectConstructor(ParseState *pstate,
JsonObjectConstructor *ctor);
static Node *transformJsonArrayConstructor(ParseState *pstate,
@@ -112,7 +114,7 @@ static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
static Node *makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location);
+ char *attrname, bool fenced, int location);
/*
@@ -377,6 +379,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
result = transformJsonFuncExpr(pstate, (JsonFuncExpr *) expr);
break;
+ case T_VariableFence:
+ result = transformVariableFence(pstate, (VariableFence *) expr);
+ break;
+
default:
/* should not reach here */
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
@@ -1028,7 +1034,20 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
node = makeParamSessionVariable(pstate,
varid, typid, typmod, collid,
- attrname, cref->location);
+ attrname, false, cref->location);
+
+ /*
+ * The variable is not inside variable's fence, so raise warning
+ * when variable fence guard is active and the query has FROM
+ * clause.
+ */
+ if (session_variables_use_fence_warning_guard && pstate->p_rtable)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is not used inside variable fence",
+ NameListToString(cref->fields)),
+ errdetail("The collision of session variable' names and column names is possible."),
+ parser_errposition(pstate, cref->location)));
}
}
}
@@ -1071,7 +1090,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
static Node *
makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location)
+ char *attrname, bool fenced, int location)
{
Param *param;
@@ -1079,6 +1098,7 @@ makeParamSessionVariable(ParseState *pstate,
param->paramkind = PARAM_VARIABLE;
param->paramvarid = varid;
+ param->paramvarfenced = fenced;
param->paramtype = typid;
param->paramtypmod = typmod;
param->paramcollid = collid;
@@ -1157,6 +1177,54 @@ transformParamRef(ParseState *pstate, ParamRef *pref)
return result;
}
+static Node *
+transformVariableFence(ParseState *pstate, VariableFence *vf)
+{
+ Node *result;
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* VariableFence can be used only in context when variables are supported */
+ if (!expr_kind_allows_session_variables(pstate->p_expr_kind))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable reference is not supported here"),
+ parser_errposition(pstate, vf->location)));
+
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(vf->varname, &attrname, ¬_unique, false);
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ result = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, true, vf->location);
+ }
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ return result;
+}
+
/* Test whether an a_expr is a plain NULL constant or not */
static bool
exprIsNullConstant(Node *arg)
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d5..cf01bff65a9 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -2034,6 +2034,13 @@ FigureColnameInternal(Node *node, char **name)
(int) ((JsonFuncExpr *) node)->op);
}
break;
+ case T_VariableFence:
+ {
+ /* return last field name */
+ *name = strVal(llast(((VariableFence *) node)->varname));
+ return 2;
+ }
+ break;
default:
break;
}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 7417054c38f..106f82b8bb5 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8682,8 +8682,16 @@ get_parameter(Param *param, deparse_context *context)
/* translate paramvarid to session variable name */
if (param->paramkind == PARAM_VARIABLE)
{
- appendStringInfo(context->buf, "%s",
- generate_session_variable_name(param->paramvarid));
+ if (param->paramvarfenced)
+ {
+ appendStringInfo(context->buf, "VARIABLE(%s)",
+ generate_session_variable_name(param->paramvarid));
+ }
+ else
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ }
return;
}
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 256cc33e719..237b1212e7a 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1625,6 +1625,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_use_fence_warning_guard", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when variable is not used inside variable fence."),
+ NULL
+ },
+ &session_variables_use_fence_warning_guard,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 8e17eaca0dd..b84e8659ae1 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -736,6 +736,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_deferrable = off
#session_replication_role = 'origin'
#session_variables_ambiguity_warning = off
+#session_variables_use_fence_warning_guard = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 0270945e048..d5f00cf3702 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -321,6 +321,16 @@ typedef struct ParamRef
ParseLoc location; /* token location, or -1 if unknown */
} ParamRef;
+/*
+ * VariableFence - ensure so fields will be interpretted as a variable
+ */
+typedef struct VariableFence
+{
+ NodeTag type;
+ List *varname; /* variable name (String nodes) */
+ ParseLoc location; /* token location, or -1 if unknown */
+} VariableFence;
+
/*
* A_Expr - infix, prefix, and postfix expressions
*/
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 2fa9b1bcd04..98b9285a54b 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -411,6 +411,8 @@ typedef struct Param
* param is used just for execution of UPDATE operation.
*/
bool parambasenode;
+ /* true when variable is used inside an fence */
+ bool paramvarfenced;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index d2209070181..5bde43758d1 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -18,6 +18,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
extern PGDLLIMPORT bool session_variables_ambiguity_warning;
+extern PGDLLIMPORT bool session_variables_use_fence_warning_guard;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7c350ad5ef9..9ac08a14e0b 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1969,3 +1969,62 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
NOTICE: drop cascades to session variable xxtab.avar
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+CREATE SCHEMA testvar;
+SET search_path TO 'testvar';
+CREATE VARIABLE a AS int;
+LET a = 10;
+CREATE TABLE test_table(a int, b int);
+INSERT INTO test_table VALUES(20, 20);
+-- no warning
+SELECT a;
+ a
+----
+ 10
+(1 row)
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a | b
+----+----
+ 20 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a) FROM test_table;
+ a
+----
+ 10
+(1 row)
+
+ALTER TABLE test_table DROP COLUMN a;
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is not used inside variable fence
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+DROP SCHEMA testvar;
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 68be415bf26..c5420183d94 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1360,3 +1360,44 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
+
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+
+CREATE SCHEMA testvar;
+
+SET search_path TO 'testvar';
+
+CREATE VARIABLE a AS int;
+LET a = 10;
+
+CREATE TABLE test_table(a int, b int);
+
+INSERT INTO test_table VALUES(20, 20);
+
+-- no warning
+SELECT a;
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a) FROM test_table;
+
+ALTER TABLE test_table DROP COLUMN a;
+
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+
+DROP SCHEMA testvar;
+
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
--
2.48.1
[text/x-patch] v20250212-0007-GUC-session_variables_ambiguity_warning.patch (15.1K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/18-v20250212-0007-GUC-session_variables_ambiguity_warning.patch)
download | inline diff:
From 04a07d776b2c59ba435fc335abe45b8371950fb1 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 21 May 2024 17:55:24 +0200
Subject: [PATCH 07/22] GUC session_variables_ambiguity_warning
Inside an query the session variables can be shadowed. This behaviour is by design,
because this ensuring so new variables doesn't break existing queries. But this
behaviour can be confusing, because shadowing is quiet.
When new GUC session_variables_ambiguity_warning is on, then the warning
is displayed, when some session variable can be used, but it is not used
due shadowing. This feature should to help with investigation of unexpected
behaviour.
Note: PLpgSQL has an option that controls priority of identifier's spaces
(SQL or PLpgSQL). Default behaviour doesn't allows collisions. I believe
this default is the best. I cannot to implement similar very strict
behaviour to session variables, because one unhappy named session variable
can breaks an applications. The problems related to badly named PLpgSQL's
varible is limitted just to only one routine.
---
doc/src/sgml/config.sgml | 60 +++++++++++++++++++
doc/src/sgml/ddl.sgml | 11 ++++
src/backend/parser/parse_expr.c | 49 +++++++++++++--
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/parser/parse_expr.h | 1 +
.../src/expected/plpgsql_session_variable.out | 33 ++++++++++
.../src/sql/plpgsql_session_variable.sql | 29 +++++++++
.../regress/expected/session_variables.out | 26 ++++++++
src/test/regress/sql/session_variables.sql | 26 ++++++++
10 files changed, 241 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 3b557ecabfb..61de7059d75 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -10937,6 +10937,66 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-ambiguity-warning" xreflabel="session_variables_ambiguity_warning">
+ <term><varname>session_variables_ambiguity_warning</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_ambiguity_warning</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when any identifier in a query could be
+ used as both a column identifier, routine variable or a session
+ variable identifier. The default is <literal>off</literal>.
+ </para>
+ <para>
+ Session variables can be shadowed by column references in a query, this
+ is an expected behavior. Previously working queries shouldn't error out
+ by creating any session variable, so session variables are always shadowed
+ if an identifier is ambiguous. Variables should be referenced using
+ anunambiguous identifier without any possibility for a collision with
+ identifier of other database objects (column names or record fields names).
+ The warning messages emitted when enabling <varname>session_variables_ambiguity_warning</varname>
+ can help finding such identifier collision.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE a int;
+LET a = 100;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+ a
+----
+ 10
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_ambiguity_warning TO on;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a FROM foo;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a
+----
+ 10
+(1 row)
+</screen>
+ </para>
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. For testing or development environments it's recommended to
+ enable it if you use session variables.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 5e671d5be4d..96912aaa436 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5445,6 +5445,17 @@ SELECT name FROM foo;
Alice
</programlisting>
</para>
+
+ <para>
+ When a query contains identifiers or qualified identifiers that could be
+ used as both a session variable identifiers and as column identifier,
+ then the column identifier is preferred every time. Warnings can be
+ emitted when this situation happens by enabling configuration parameter <xref
+ linkend="guc-session-variables-ambiguity-warning"/>. User can explicitly
+ qualify the source object by syntax <literal>table.column</literal> or
+ <literal>schema.variable</literal>. It is strongly recommended to rename
+ shadowed variables or use qualified names always.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 4f208c7efdd..63f1732f69e 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -45,6 +45,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
+bool session_variables_ambiguity_warning = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -960,11 +961,51 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
*
* SELECT foo.a, foo.b, foo.c FROM foo;
*
- * However, that is very confusing, so we disallow it. We don't try to
- * identify a variable if we know that it would be shadowed.
- * -----
+ * However, that is very confusing, so we disallow it.
+ *
+ * When session_variables_ambiguity_warning is requested, then we
+ * need to identify a variable although we know, so this variable
+ * would be shadowed.
*/
- if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ if (node || (relname && crerr == CRERR_NO_COLUMN))
+ {
+ /*
+ * In this path we just try (if it is wanted) detect if session
+ * variable is shadowed.
+ */
+ if (session_variables_ambiguity_warning)
+ {
+ /*
+ * The AccessShareLock is created on related session variable.
+ * The lock will be kept for the whole transaction.
+ */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, true);
+
+ if (OidIsValid(varid))
+ {
+ /* this path will ending by WARNING. Unlock variable first */
+ UnlockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (node)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is shadowed",
+ NameListToString(cref->fields)),
+ errdetail("Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name."),
+ parser_errposition(pstate, cref->location)));
+ else
+ /* session variable is shadowed by RTE */
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s.%s\" is shadowed",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ errdetail("Session variables can be shadowed by tables or table's aliases with the same name."),
+ parser_errposition(pstate, cref->location)));
+ }
+ }
+ }
+ else
{
/* takes an AccessShareLock on the session variable */
varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 226af43fe23..256cc33e719 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1616,6 +1616,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_ambiguity_warning", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when reference to a session variable is ambiguous."),
+ NULL
+ },
+ &session_variables_ambiguity_warning,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index d472987ed46..8e17eaca0dd 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -735,6 +735,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_read_only = off
#default_transaction_deferrable = off
#session_replication_role = 'origin'
+#session_variables_ambiguity_warning = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index efbaff8e710..d2209070181 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -17,6 +17,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
+extern PGDLLIMPORT bool session_variables_ambiguity_warning;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index ab779900596..a6523f7afe2 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -354,6 +354,39 @@ $$;
NOTICE: session variable is 100
NOTICE: plpgsql variable is 1000
NOTICE: variable is 1000
+-- againt with session_variables_ambiguity_warning(on)
+SET session_variables_ambiguity_warning TO on;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+WARNING: session variable "plpgsql_sv_var1" is shadowed
+LINE 1: plpgsql_sv_var1
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+QUERY: plpgsql_sv_var1
+NOTICE: variable is 1000
+SET session_variables_ambiguity_warning TO off;
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
CREATE VARIABLE plpgsql_sv_v text;
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
index a3cc264cf38..9b8e90e81fa 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -260,6 +260,35 @@ BEGIN
END;
$$;
+-- againt with session_variables_ambiguity_warning(on)
+
+SET session_variables_ambiguity_warning TO on;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+SET session_variables_ambiguity_warning TO off;
+
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 2783caa8446..7c350ad5ef9 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1524,6 +1524,9 @@ CREATE TABLE vartest_foo(a int, b int);
INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
-- should to fail
SELECT var1.* FROM vartest_foo;
ERROR: missing FROM-clause entry for table "var1"
@@ -1549,6 +1552,7 @@ SELECT count(var1.*) FROM vartest_foo var1;
2
(1 row)
+SET session_variables_ambiguity_warning TO off;
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
NOTICE: drop cascades to 2 other objects
@@ -1943,3 +1947,25 @@ SELECT var1;
(1 row)
DROP VARIABLE var1, var2;
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+CREATE VARIABLE xxtab.avar int;
+CREATE TABLE public.xxtab(avar int);
+INSERT INTO public.xxtab VALUES(1);
+LET xxtab.avar = 20;
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+WARNING: session variable "xxtab.avar" is shadowed
+LINE 1: SELECT xxtab.avar FROM public.xxtab;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ avar
+------
+ 1
+(1 row)
+
+SET session_variables_ambiguity_warning TO off;
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
+NOTICE: drop cascades to session variable xxtab.avar
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index a624ab8b67f..68be415bf26 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1079,6 +1079,10 @@ INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
+
-- should to fail
SELECT var1.* FROM vartest_foo;
@@ -1091,6 +1095,8 @@ SELECT count(var1.*) FROM vartest_foo;
-- should be ok
SELECT count(var1.*) FROM vartest_foo var1;
+SET session_variables_ambiguity_warning TO off;
+
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
@@ -1334,3 +1340,23 @@ BEGIN; DROP VARIABLE var1; ROLLBACK;
SELECT var1;
DROP VARIABLE var1, var2;
+
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+
+CREATE VARIABLE xxtab.avar int;
+
+CREATE TABLE public.xxtab(avar int);
+
+INSERT INTO public.xxtab VALUES(1);
+
+LET xxtab.avar = 20;
+
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+
+SET session_variables_ambiguity_warning TO off;
+
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
--
2.48.1
[text/x-patch] v20250212-0006-plpgsql-tests.patch (16.9K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/19-v20250212-0006-plpgsql-tests.patch)
download | inline diff:
From 490d43eb830c967c8f95d39eaea8606bdec29f4f Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 14:06:06 +0100
Subject: [PATCH 06/22] plpgsql tests
---
src/pl/plpgsql/src/Makefile | 3 +-
.../src/expected/plpgsql_session_variable.out | 382 ++++++++++++++++++
src/pl/plpgsql/src/meson.build | 1 +
.../src/sql/plpgsql_session_variable.sql | 289 +++++++++++++
4 files changed, 674 insertions(+), 1 deletion(-)
create mode 100644 src/pl/plpgsql/src/expected/plpgsql_session_variable.out
create mode 100644 src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile
index 63cb96fae3e..bbcae27d422 100644
--- a/src/pl/plpgsql/src/Makefile
+++ b/src/pl/plpgsql/src/Makefile
@@ -35,7 +35,8 @@ REGRESS_OPTS = --dbname=$(PL_TESTDB)
REGRESS = plpgsql_array plpgsql_cache plpgsql_call plpgsql_control \
plpgsql_copy plpgsql_domain plpgsql_misc \
plpgsql_record plpgsql_simple plpgsql_transaction \
- plpgsql_trap plpgsql_trigger plpgsql_varprops
+ plpgsql_trap plpgsql_trigger plpgsql_varprops \
+ plpgsql_session_variable
# where to find gen_keywordlist.pl and subsidiary files
TOOLSDIR = $(top_srcdir)/src/tools
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
new file mode 100644
index 00000000000..ab779900596
--- /dev/null
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -0,0 +1,382 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+LET plpgsql_sv_var = pi();
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+NOTICE: value of session variable is 3.14159265358979
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+ pi_multiply_2
+------------------
+ 6.28318530717959
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var;
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+END;
+-- execute outside of a transaction
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP FUNCTION test_func();
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+SET ROLE TO regress_var_owner_role;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_reader_role;
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail
+SELECT var_read_func();
+ERROR: permission denied for session variable plpgsql_sv_var1
+CONTEXT: PL/pgSQL expression "plpgsql_sv_var1"
+PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should be ok
+SELECT var_read_func();
+NOTICE: 10
+ var_read_func
+---------------
+
+(1 row)
+
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+DROP VARIABLE plpgsql_sv_var1;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail, but not crash
+SELECT var_read_func();
+ERROR: column "plpgsql_sv_var1" does not exist
+LINE 1: plpgsql_sv_var1
+ ^
+QUERY: plpgsql_sv_var1
+CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+DROP FUNCTION var_read_func;
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+ inc_var_int
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+LET plpgsql_sv_var2 = 0.0;
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+ inc_var_num
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+NOTICE: variable is 1000
+DROP VARIABLE plpgsql_sv_var1;
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+select ffunc();
+ ffunc
+-------
+ abc
+(1 row)
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+DROP VARIABLE plpgsql_sv_v;
diff --git a/src/pl/plpgsql/src/meson.build b/src/pl/plpgsql/src/meson.build
index 33c49ac25d9..1d01d1c2629 100644
--- a/src/pl/plpgsql/src/meson.build
+++ b/src/pl/plpgsql/src/meson.build
@@ -88,6 +88,7 @@ tests += {
'plpgsql_trap',
'plpgsql_trigger',
'plpgsql_varprops',
+ 'plpgsql_session_variable',
],
},
}
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
new file mode 100644
index 00000000000..a3cc264cf38
--- /dev/null
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -0,0 +1,289 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+
+LET plpgsql_sv_var = pi();
+
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+
+DROP VARIABLE plpgsql_sv_var;
+
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+END;
+
+-- execute outside of a transaction
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+SELECT test_func();
+
+DROP FUNCTION test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+SET ROLE TO regress_var_owner_role;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_reader_role;
+
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should be ok
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail, but not crash
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+DROP FUNCTION var_read_func;
+
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+
+LET plpgsql_sv_var2 = 0.0;
+
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+
+select ffunc();
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+
+DROP VARIABLE plpgsql_sv_v;
--
2.48.1
[text/x-patch] v20250212-0004-DISCARD-VARIABLES.patch (9.6K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/20-v20250212-0004-DISCARD-VARIABLES.patch)
download | inline diff:
From e508042bbf5c9806e47dc0c7c44a975d0db618eb Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sun, 28 Jan 2024 20:54:20 +0100
Subject: [PATCH 04/22] DISCARD VARIABLES
Implementation of DISCARD VARIABLES commands by removing hash table with session variables
and resetting related memory context.
---
doc/src/sgml/ref/discard.sgml | 13 +++-
src/backend/commands/discard.c | 6 ++
src/backend/commands/session_variable.c | 28 ++++++++-
src/backend/parser/gram.y | 6 ++
src/backend/tcop/utility.c | 3 +
src/bin/psql/tab-complete.in.c | 2 +-
src/include/commands/session_variable.h | 2 +
src/include/nodes/parsenodes.h | 1 +
src/include/tcop/cmdtaglist.h | 1 +
.../regress/expected/session_variables.out | 63 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 36 +++++++++++
11 files changed, 158 insertions(+), 3 deletions(-)
diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
index bf44c523cac..61b967f9c9b 100644
--- a/doc/src/sgml/ref/discard.sgml
+++ b/doc/src/sgml/ref/discard.sgml
@@ -21,7 +21,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
+DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES }
</synopsis>
</refsynopsisdiv>
@@ -66,6 +66,16 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>VARIABLES</literal></term>
+ <listitem>
+ <para>
+ Resets the value of all session variables. If a variable
+ is later reused, it is re-initialized to <literal>NULL</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><literal>TEMPORARY</literal> or <literal>TEMP</literal></term>
<listitem>
@@ -93,6 +103,7 @@ SELECT pg_advisory_unlock_all();
DISCARD PLANS;
DISCARD TEMP;
DISCARD SEQUENCES;
+DISCARD VARIABLES;
</programlisting></para>
</listitem>
</varlistentry>
diff --git a/src/backend/commands/discard.c b/src/backend/commands/discard.c
index 81339a75a52..5904a6c4917 100644
--- a/src/backend/commands/discard.c
+++ b/src/backend/commands/discard.c
@@ -18,6 +18,7 @@
#include "commands/async.h"
#include "commands/discard.h"
#include "commands/prepare.h"
+#include "commands/session_variable.h"
#include "commands/sequence.h"
#include "utils/guc.h"
#include "utils/portal.h"
@@ -48,6 +49,10 @@ DiscardCommand(DiscardStmt *stmt, bool isTopLevel)
ResetTempTableNamespace();
break;
+ case DISCARD_VARIABLES:
+ ResetSessionVariables();
+ break;
+
default:
elog(ERROR, "unrecognized DISCARD target: %d", stmt->target);
}
@@ -75,4 +80,5 @@ DiscardAll(bool isTopLevel)
ResetPlanCache();
ResetTempTableNamespace();
ResetSequenceCaches();
+ ResetSessionVariables();
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 8255f360d2e..a621cbe3328 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -94,7 +94,13 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
- Assert(sessionvars);
+ /*
+ * There is no guarantee of session variables being initialized, even when
+ * receiving an invalidation callback, as DISCARD [ ALL | VARIABLES ]
+ * destroys the hash table entirely.
+ */
+ if (!sessionvars)
+ return;
/*
* If the hashvalue is not specified, we have to recheck all currently
@@ -619,3 +625,23 @@ pg_session_variables(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+
+/*
+ * Fast drop of the complete content of the session variables hash table, and
+ * cleanup of any list that wouldn't be relevant anymore.
+ * This is used by the DISCARD VARIABLES (and DISCARD ALL) command.
+ */
+void
+ResetSessionVariables(void)
+{
+ /* destroy hash table and reset related memory context */
+ if (sessionvars)
+ {
+ hash_destroy(sessionvars);
+ sessionvars = NULL;
+ }
+
+ /* release memory allocated by session variables */
+ if (SVariableMemoryContext != NULL)
+ MemoryContextReset(SVariableMemoryContext);
+}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index d34ea39bc83..77d9246f4a1 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -2084,7 +2084,13 @@ DiscardStmt:
n->target = DISCARD_SEQUENCES;
$$ = (Node *) n;
}
+ | DISCARD VARIABLES
+ {
+ DiscardStmt *n = makeNode(DiscardStmt);
+ n->target = DISCARD_VARIABLES;
+ $$ = (Node *) n;
+ }
;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 7a508a3644f..6e4d2310f5c 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -2962,6 +2962,9 @@ CreateCommandTag(Node *parsetree)
case DISCARD_SEQUENCES:
tag = CMDTAG_DISCARD_SEQUENCES;
break;
+ case DISCARD_VARIABLES:
+ tag = CMDTAG_DISCARD_VARIABLES;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 57364ea6a1c..0cc8eb56bb4 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4117,7 +4117,7 @@ match_previous_words(int pattern_id,
/* DISCARD */
else if (Matches("DISCARD"))
- COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP");
+ COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP", "VARIABLES");
/* DO */
else if (Matches("DO"))
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index 2391b9ad443..a8ca43c87af 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -27,4 +27,6 @@ extern Datum GetSessionVariable(Oid varid, bool *isNull);
extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
QueryEnvironment *queryEnv, QueryCompletion *qc);
+extern void ResetSessionVariables(void);
+
#endif
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index b1e9efa6979..0270945e048 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -4036,6 +4036,7 @@ typedef enum DiscardMode
DISCARD_PLANS,
DISCARD_SEQUENCES,
DISCARD_TEMP,
+ DISCARD_VARIABLES,
} DiscardMode;
typedef struct DiscardStmt
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index 22082c30008..bef0ac25331 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -135,6 +135,7 @@ PG_CMDTAG(CMDTAG_DISCARD_ALL, "DISCARD ALL", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_PLANS, "DISCARD PLANS", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_SEQUENCES, "DISCARD SEQUENCES", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_TEMP, "DISCARD TEMP", false, false, false)
+PG_CMDTAG(CMDTAG_DISCARD_VARIABLES, "DISCARD VARIABLES", false, false, false)
PG_CMDTAG(CMDTAG_DO, "DO", false, false, false)
PG_CMDTAG(CMDTAG_DROP_ACCESS_METHOD, "DROP ACCESS METHOD", true, false, false)
PG_CMDTAG(CMDTAG_DROP_AGGREGATE, "DROP AGGREGATE", true, false, false)
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index f22467186e3..79ac40768f8 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1663,3 +1663,66 @@ DROP VARIABLE :"DBNAME".:"DBNAME".b;
DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+ var1
+-------
+ Hello
+(1 row)
+
+DISCARD ALL;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT var1;
+ var1
+------
+ AHOJ
+(1 row)
+
+DISCARD VARIABLES;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+DROP VARIABLE var1;
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS varchar;
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DISCARD VARIABLES;
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index e72360d5254..2954759aaed 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1178,3 +1178,39 @@ DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+
+DISCARD ALL;
+SELECT var1;
+
+LET var1 = 'AHOJ';
+SELECT var1;
+
+DISCARD VARIABLES;
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+
+SELECT count(*) FROM pg_session_variables();
+
+CREATE VARIABLE var1 AS varchar;
+
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+
+LET var1 = 'AHOJ';
+
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+
+DISCARD VARIABLES;
+
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
--
2.48.1
[text/x-patch] v20250212-0005-memory-cleaning-after-DROP-VARIABLE.patch (20.9K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/21-v20250212-0005-memory-cleaning-after-DROP-VARIABLE.patch)
download | inline diff:
From e03bb1a807530d037cd237526d449af86913d427 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 09:31:28 +0100
Subject: [PATCH 05/22] memory cleaning after DROP VARIABLE
Accepting a sinval message invalidates entries in the "sessionvars" hash table.
These entries are validated before any read or write operations on session variables.
When the entry cannot be validated, it is removed. Removal will be delayed when
the variable was dropped by the current transaction, which could still be rolled back.
---
src/backend/catalog/pg_variable.c | 7 +-
src/backend/commands/session_variable.c | 153 +++++++++++-
src/include/commands/session_variable.h | 2 +
.../isolation/expected/session-variable.out | 110 +++++++++
src/test/isolation/isolation_schedule | 1 +
.../isolation/specs/session-variable.spec | 50 ++++
.../regress/expected/session_variables.out | 217 ++++++++++++++++++
src/test/regress/sql/session_variables.sql | 120 ++++++++++
8 files changed, 655 insertions(+), 5 deletions(-)
create mode 100644 src/test/isolation/expected/session-variable.out
create mode 100644 src/test/isolation/specs/session-variable.spec
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index bb445e9434b..d672d2a9cb3 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -22,6 +22,7 @@
#include "catalog/pg_collation.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
@@ -230,7 +231,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
}
/*
- * Drop variable by OID
+ * Drop variable by OID, and register the needed session variable
+ * cleanup.
*/
void
DropVariableById(Oid varid)
@@ -250,4 +252,7 @@ DropVariableById(Oid varid)
ReleaseSysCache(tup);
table_close(rel, RowExclusiveLock);
+
+ /* do the necessary cleanup in local memory, if needed */
+ SessionVariableDropPostprocess(varid);
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index a621cbe3328..4a29ed6e0c3 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -14,6 +14,7 @@
*/
#include "postgres.h"
+#include "access/xact.h"
#include "catalog/pg_variable.h"
#include "commands/session_variable.h"
#include "executor/svariableReceiver.h"
@@ -67,6 +68,14 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ /*
+ * Top level local transaction id of the last transaction that dropped the
+ * variable, if any. We need this information to avoid freeing memory for
+ * variables dropped by the local backend, in case the operation is rolled
+ * back.
+ */
+ LocalTransactionId drop_lxid;
+
/*
* Stored value and type description can be outdated when we receive a
* sinval message. We then have to check if the stored data are still
@@ -83,6 +92,17 @@ static HTAB *sessionvars = NULL; /* hash table for session variables */
static MemoryContext SVariableMemoryContext = NULL;
+/* becomes true when we receive a sinval message */
+static bool needs_validation = false;
+
+/*
+ * The content of dropped session variables is not removed immediately. We do
+ * that in the next transaction that reads or writes a session variable.
+ * "validated_lxid" stores the transaction that performed said validation, so
+ * that we can avoid repeating the effort.
+ */
+static LocalTransactionId validated_lxid = InvalidLocalTransactionId;
+
/*
* Callback function for session variable invalidation.
*/
@@ -114,6 +134,38 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
if (hashvalue == 0 || svar->hashvalue == hashvalue)
{
svar->is_valid = false;
+ needs_validation = true;
+ }
+ }
+}
+
+/*
+ * Handle the local memory cleanup for a DROP VARIABLE command.
+ *
+ * Caller should take care of removing the pg_variable entry first.
+ */
+void
+SessionVariableDropPostprocess(Oid varid)
+{
+ Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid));
+
+ if (sessionvars)
+ {
+ bool found;
+ SVariable svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_FIND, &found);
+
+ if (found)
+ {
+ /*
+ * Save the current top level local transaction id to make sure we
+ * won't automatically remove the local variable storage in
+ * validate_all_session_variables() when the invalidation message
+ * from DROP VARIABLE arrives. After all, the transaction could
+ * still be rolled back.
+ */
+ svar->is_valid = false;
+ svar->drop_lxid = MyProc->vxid.lxid;
}
}
}
@@ -167,6 +219,67 @@ is_session_variable_valid(SVariable svar)
return result;
}
+/*
+ * Check all potentially invalid session variable data in local memory and free
+ * the memory for all invalid ones. This function is called before any read or
+ * write of a session variable. Freeing of a variable's memory is postponed if
+ * the variable has been dropped by the current transaction, since that
+ * operation could still be rolled back.
+ *
+ * It is possible that we receive a cache invalidation message while
+ * remove_invalid_session_variables() is executing, so we cannot guarantee that
+ * all entries in "sessionvars" will be set to "is_valid" after the function is
+ * done. However, we can guarantee that all entries get checked once.
+ */
+static void
+remove_invalid_session_variables(void)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ /*
+ * The validation requires system catalog access, so the session state
+ * should be "in transaction".
+ */
+ Assert(IsTransactionState());
+
+ if (!needs_validation || !sessionvars)
+ return;
+
+ /*
+ * Reset the flag before we start the validation. It can be set again
+ * by concurrently incoming sinval messages.
+ */
+ needs_validation = false;
+
+ elog(DEBUG1, "effective call of validate_all_session_variables()");
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (!svar->is_valid)
+ {
+ if (svar->drop_lxid == MyProc->vxid.lxid)
+ {
+ /* try again in the next transaction */
+ needs_validation = true;
+ continue;
+ }
+
+ if (!is_session_variable_valid(svar))
+ {
+ Oid varid = svar->varid;
+
+ free_session_variable_value(svar);
+ hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ else
+ svar->is_valid = true;
+ }
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
@@ -196,6 +309,8 @@ setup_session_variable(SVariable svar, Oid varid)
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+ svar->drop_lxid = InvalidTransactionId;
+
svar->isnull = true;
svar->value = (Datum) 0;
@@ -319,22 +434,42 @@ get_session_variable(Oid varid)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
if (found)
{
+ /*
+ * The session variable could have been dropped by a DROP VARIABLE
+ * statement in a subtransaction that was later rolled back, which
+ * means that we may have to work with the data of a variable marked
+ * as invalid.
+ */
if (!svar->is_valid)
{
/*
- * If there was an invalidation message, the variable might still be
- * valid, but we have to check with the system catalog.
+ * We have to check the system catalog to see if the variable is
+ * still valid, even if an invalidation message set it to invalid.
+ *
+ * The variable must be validated before it is accessed. The oid
+ * should be valid, because the related session variable is already
+ * locked, and remove_invalid_session_variables() would remove
+ * variables dropped by other transactions.
*/
if (is_session_variable_valid(svar))
svar->is_valid = true;
else
- /* if the value cannot be validated, we have to discard it */
- free_session_variable_value(svar);
+ elog(ERROR, "unexpected state of session variable %u", varid);
}
}
else
@@ -395,6 +530,16 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index a8ca43c87af..d3cc79b5608 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -21,6 +21,8 @@
#include "tcop/cmdtag.h"
#include "utils/queryenvironment.h"
+extern void SessionVariableDropPostprocess(Oid varid);
+
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
new file mode 100644
index 00000000000..0a5579dc7ce
--- /dev/null
+++ b/src/test/isolation/expected/session-variable.out
@@ -0,0 +1,110 @@
+Parsed test spec with 4 sessions
+
+starting permutation: let val drop val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+
+starting permutation: let val s1 drop val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+step sr1: ROLLBACK;
+
+starting permutation: let val dbg drop create dbg val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name|removed
+------+----+-------
+ | |t
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+
+starting permutation: let val s1 dbg drop create dbg val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+step sr1: ROLLBACK;
+
+starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+step create3: CREATE VARIABLE myvar3 AS text;
+step let3: LET myvar3 = 'test';
+step s3: BEGIN;
+step create4: CREATE VARIABLE myvar4 AS text;
+step let4: LET myvar4 = 'test';
+step drop4: DROP VARIABLE myvar4;
+step drop3: DROP VARIABLE myvar3;
+step inval3: SELECT COUNT(*) >= 0 FROM pg_foreign_table;
+?column?
+--------
+t
+(1 row)
+
+step discard: DISCARD VARIABLES;
+step sc3: COMMIT;
+step state: SELECT varname FROM pg_variable;
+varname
+-------
+myvar
+(1 row)
+
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 143109aa4da..7453685d046 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -115,3 +115,4 @@ test: serializable-parallel-2
test: serializable-parallel-3
test: matview-write-skew
test: lock-nowait
+test: session-variable
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
new file mode 100644
index 00000000000..c864fee4006
--- /dev/null
+++ b/src/test/isolation/specs/session-variable.spec
@@ -0,0 +1,50 @@
+# Test session variables memory cleanup for sinval
+
+setup
+{
+ CREATE VARIABLE myvar AS text;
+}
+
+teardown
+{
+ DROP VARIABLE IF EXISTS myvar;
+}
+
+session s1
+step s1 { BEGIN; }
+step let { LET myvar = 'test'; }
+step val { SELECT myvar; }
+step dbg { SELECT schema, name, removed FROM pg_session_variables(); }
+step sr1 { ROLLBACK; }
+
+session s2
+step drop { DROP VARIABLE myvar; }
+step create { CREATE VARIABLE myvar AS text; }
+
+session s3
+step s3 { BEGIN; }
+step let3 { LET myvar3 = 'test'; }
+step create4 { CREATE VARIABLE myvar4 AS text; }
+step let4 { LET myvar4 = 'test'; }
+step drop4 { DROP VARIABLE myvar4; }
+step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; }
+step discard { DISCARD VARIABLES; }
+step sc3 { COMMIT; }
+step state { SELECT varname FROM pg_variable; }
+
+session s4
+step create3 { CREATE VARIABLE myvar3 AS text; }
+step drop3 { DROP VARIABLE myvar3; }
+
+# Concurrent drop of a known variable should lead to an error
+permutation let val drop val
+# Same, but with an explicit transaction
+permutation let val s1 drop val sr1
+# Concurrent drop/create of a known variable should lead to empty variable
+permutation let val dbg drop create dbg val
+# Concurrent drop/create of a known variable should lead to empty variable
+# We need a transaction to make sure that we won't accept invalidation when
+# calling the dbg step after the concurrent drop
+permutation let val s1 dbg drop create dbg val sr1
+# test for DISCARD ALL when all internal queues have actions registered
+permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 79ac40768f8..2783caa8446 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1726,3 +1726,220 @@ SELECT count(*) FROM pg_session_variables();
0
(1 row)
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+-- should fail
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1, var2;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 2954759aaed..a624ab8b67f 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1214,3 +1214,123 @@ DISCARD VARIABLES;
-- should be zero again
SELECT count(*) FROM pg_session_variables();
+
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+
+-- should fail
+SELECT var1;
+
+ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ROLLBACK;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+DROP VARIABLE var1, var2;
--
2.48.1
[text/x-patch] v20250212-0003-function-pg_session_variables-for-cleaning-tests.patch (4.3K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/22-v20250212-0003-function-pg_session_variables-for-cleaning-tests.patch)
download | inline diff:
From 32ff5aef54c8d95a30396ca0fc365322317ea062 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 20:01:56 +0100
Subject: [PATCH 03/22] function pg_session_variables for cleaning tests
This is a function designed for testing and debugging. It returns the
content of sessionvars as-is, and can therefore display entries about
session variables that were dropped but for which this backend didn't
process the shared invalidations yet.
---
src/backend/commands/session_variable.c | 92 +++++++++++++++++++++++++
src/include/catalog/pg_proc.dat | 8 +++
2 files changed, 100 insertions(+)
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 2456a3452b9..8255f360d2e 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -527,3 +527,95 @@ ExecuteLetStmt(ParseState *pstate,
PopActiveSnapshot();
}
+
+/*
+ * pg_session_variables - designed for testing
+ *
+ * This is a function designed for testing and debugging. It returns the
+ * content of session variables as-is, and can therefore display data about
+ * session variables that were dropped, but for which this backend didn't
+ * process the shared invalidations yet.
+ */
+Datum
+pg_session_variables(PG_FUNCTION_ARGS)
+{
+#define NUM_PG_SESSION_VARIABLES_ATTS 8
+
+ InitMaterializedSRF(fcinfo, 0);
+
+ if (sessionvars)
+ {
+ ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ Datum values[NUM_PG_SESSION_VARIABLES_ATTS];
+ bool nulls[NUM_PG_SESSION_VARIABLES_ATTS];
+ HeapTuple tp;
+ bool var_is_valid = false;
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, 0, sizeof(nulls));
+
+ values[0] = ObjectIdGetDatum(svar->varid);
+ values[3] = ObjectIdGetDatum(svar->typid);
+
+ /*
+ * It is possible that the variable has been dropped from the
+ * catalog, but not yet purged from the hash table.
+ */
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ Form_pg_variable varform = (Form_pg_variable) GETSTRUCT(tp);
+
+ /*
+ * It is also possible that a variable has been dropped and
+ * someone created a new variable with the same object ID. Use
+ * the catalog information only if that is not the case.
+ */
+ if (svar->create_lsn == varform->varcreate_lsn)
+ {
+ values[1] = CStringGetTextDatum(
+ get_namespace_name(varform->varnamespace));
+
+ values[2] = CStringGetTextDatum(NameStr(varform->varname));
+ values[4] = CStringGetTextDatum(format_type_be(svar->typid));
+ values[5] = BoolGetDatum(false);
+
+ values[6] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_SELECT) == ACLCHECK_OK);
+
+ values[7] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_UPDATE) == ACLCHECK_OK);
+
+ var_is_valid = true;
+ }
+
+ ReleaseSysCache(tp);
+ }
+
+ /* if there is no matching catalog entry, return null values */
+ if (!var_is_valid)
+ {
+ nulls[1] = true;
+ nulls[2] = true;
+ nulls[4] = true;
+ values[5] = BoolGetDatum(true);
+ nulls[6] = true;
+ nulls[7] = true;
+ }
+
+ tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
+ }
+ }
+
+ return (Datum) 0;
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 162cd048965..fffc21af420 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -12487,4 +12487,12 @@
proargtypes => 'int4',
prosrc => 'gist_stratnum_common' },
+# Session variables support
+{ oid => '8488', descr => 'list of used session variables',
+ proname => 'pg_session_variables', prorows => '1000', proretset => 't',
+ provolatile => 's', proparallel => 'r', prorettype => 'record',
+ proargtypes => '', proallargtypes => '{oid,text,text,oid,text,bool,bool,bool}',
+ proargmodes => '{o,o,o,o,o,o,o,o}',
+ proargnames => '{varid,schema,name,typid,typname,removed,can_select,can_update}',
+ prosrc => 'pg_session_variables' },
]
--
2.48.1
[text/x-patch] v20250212-0002-Storage-for-session-variables-and-SQL-interface.patch (159.6K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/23-v20250212-0002-Storage-for-session-variables-and-SQL-interface.patch)
download | inline diff:
From c5aab9a3f4704e7904710d9b608ce284ffd2543e Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Thu, 6 Jul 2023 08:29:21 +0200
Subject: [PATCH 02/22] Storage for session variables and SQL interface
Session variables are stored in session memory in a dedicated hash table.
They are set by the LET command and read by the SELECT command.
The access rights should be checked.
The identifiers of session variables should always be shadowed by possible
column identifiers: we don't want to break an application by creating some
badly named session variable.
The limits of this patch (solved by other patches):
- session variables block parallel execution
- session variables blocks simple expression evaluation (in plpgsql)
- SQL functions with session variables are not inlined
- CALL statement is not supported (usage of direct access to express executor)
- EXECUTE statement is not supported (usage of direct access to express executor)
- memory used by dropped session variables is not released
Implementations of EXPLAIN LET and PREPARE LET statements
are in separate patches (for better readability)
---
doc/src/sgml/catalogs.sgml | 13 +
doc/src/sgml/ddl.sgml | 61 +
doc/src/sgml/func.sgml | 4 +-
doc/src/sgml/glossary.sgml | 5 +-
doc/src/sgml/parallel.sgml | 6 +
doc/src/sgml/plpgsql.sgml | 14 +
doc/src/sgml/ref/allfiles.sgml | 1 +
doc/src/sgml/ref/alter_variable.sgml | 1 +
doc/src/sgml/ref/create_variable.sgml | 5 +-
doc/src/sgml/ref/drop_variable.sgml | 1 +
doc/src/sgml/ref/let.sgml | 96 ++
doc/src/sgml/reference.sgml | 1 +
src/backend/catalog/dependency.c | 5 +
src/backend/catalog/namespace.c | 289 ++++
src/backend/catalog/pg_variable.c | 2 +
src/backend/commands/Makefile | 1 +
src/backend/commands/meson.build | 1 +
src/backend/commands/prepare.c | 10 +
src/backend/commands/session_variable.c | 529 +++++++
src/backend/executor/Makefile | 1 +
src/backend/executor/execExpr.c | 32 +
src/backend/executor/execMain.c | 66 +
src/backend/executor/meson.build | 1 +
src/backend/executor/svariableReceiver.c | 172 +++
src/backend/nodes/nodeFuncs.c | 10 +
src/backend/optimizer/plan/planner.c | 36 +
src/backend/optimizer/plan/setrefs.c | 156 ++-
src/backend/optimizer/prep/prepjointree.c | 3 +
src/backend/optimizer/util/clauses.c | 33 +-
src/backend/parser/analyze.c | 272 +++-
src/backend/parser/gram.y | 39 +-
src/backend/parser/parse_agg.c | 9 +
src/backend/parser/parse_expr.c | 223 ++-
src/backend/parser/parse_func.c | 2 +
src/backend/parser/parse_merge.c | 1 +
src/backend/tcop/dest.c | 7 +
src/backend/tcop/utility.c | 16 +
src/backend/utils/adt/ruleutils.c | 46 +
src/backend/utils/cache/plancache.c | 41 +-
src/backend/utils/fmgr/fmgr.c | 10 +-
src/bin/psql/tab-complete.in.c | 12 +-
src/include/catalog/namespace.h | 1 +
src/include/catalog/pg_variable.h | 9 +
src/include/commands/session_variable.h | 30 +
src/include/executor/svariableReceiver.h | 22 +
src/include/nodes/execnodes.h | 14 +
src/include/nodes/parsenodes.h | 17 +
src/include/nodes/pathnodes.h | 14 +
src/include/nodes/plannodes.h | 9 +
src/include/nodes/primnodes.h | 14 +
src/include/optimizer/planmain.h | 2 +
src/include/parser/kwlist.h | 1 +
src/include/parser/parse_node.h | 3 +
src/include/tcop/cmdtaglist.h | 1 +
src/include/tcop/dest.h | 1 +
src/pl/plpgsql/src/pl_exec.c | 3 +-
.../regress/expected/session_variables.out | 1232 +++++++++++++++++
src/test/regress/sql/session_variables.sql | 883 ++++++++++++
src/tools/pgindent/typedefs.list | 5 +
59 files changed, 4467 insertions(+), 27 deletions(-)
create mode 100644 doc/src/sgml/ref/let.sgml
create mode 100644 src/backend/commands/session_variable.c
create mode 100644 src/backend/executor/svariableReceiver.c
create mode 100644 src/include/commands/session_variable.h
create mode 100644 src/include/executor/svariableReceiver.h
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 7ba91b1f4b1..4f502274bfa 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9810,6 +9810,19 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcreate_lsn</structfield> <type>pg_lsn</type>
+ </para>
+ <para>
+ LSN of the transaction where the variable was created.
+ <structfield>varcreate_lsn</structfield> and
+ <structfield>oid</structfield> together form the all-time unique
+ identifier (<structfield>oid</structfield> alone is not enough, since
+ object identifiers can get reused).
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>varname</structfield> <type>name</type>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index edfb7db24fc..5e671d5be4d 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5384,6 +5384,67 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
The session variable holds value in session memory. This value is private
to each session and is released when the session ends.
</para>
+
+ <para>
+ The value of a session variable is set with the SQL statement
+ <command>LET</command>. The value of a session variable can be retrieved
+ with the SQL statement <command>SELECT</command>.
+<programlisting>
+CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
+</programlisting>
+
+ or
+
+<programlisting>
+CREATE VARIABLE public.current_user_id AS integer;
+GRANT SELECT ON VARIABLE public.current_user_id TO PUBLIC;
+LET current_user_id = (SELECT id FROM users WHERE usename = session_user);
+SELECT current_user_id;
+</programlisting>
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a variable's value returns a <literal>NULL</literal>, unless its value has
+ been set to something else in the current session using the
+ <command>LET</command> command. Session variables are not transactional:
+ any changes made to the value of a session variable in a transaction won't
+ be undone if the transaction is rolled back (just like variables in
+ procedural languages). Session variables themselves are persistent, but
+ their values are neither persistent nor shared (like the content of
+ temporary tables).
+ </para>
+
+ <para>
+ Inside a query or an expression, a session variable can be
+ <quote>shadowed</quote> by a column with the same name. Similarly, the
+ name of a function or procedure argument or a PL/pgSQL variable (see
+ <xref linkend="plpgsql-declarations"/>) can shadow a session variable
+ in the routine's body. Such collisions of identifiers can be resolved
+ by using qualified identifiers: Session variables can be qualified with
+ the schema name, columns can use table aliases, routine variables can use
+ block labels, and routine arguments can use the routine name.
+<programlisting>
+CREATE VARIABLE name AS text;
+LET name = 'John';
+
+CREATE TABLE foo(name text);
+INSERT INTO foo VALUES('Alice');
+
+-- variable name is shadowed
+SELECT name FROM foo;
+</programlisting>
+
+ which returns:
+
+<programlisting>
+ name
+-------
+ Alice
+</programlisting>
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 4a484034c0f..0cacd92e165 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25595,8 +25595,8 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
't' for <literal>TABLESPACE</literal>,
'F' for <literal>FOREIGN DATA WRAPPER</literal>,
'S' for <literal>FOREIGN SERVER</literal>,
- or
- 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal>.
+ 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal> or
+ 'V' for <literal>SESSION VARIABLE</literal>.
</para></entry>
</row>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index b921f5a3339..81988f2dfea 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1675,8 +1675,9 @@
<para>
A persistent database object that holds a value in session memory. This
value is private to each session and is released when the session ends.
- Read or write access to session variables is controlled by privileges,
- similar to other database objects.
+ The default value of the session variable is null. Read or write access
+ to session variables is controlled by privileges, similar to other database
+ objects.
</para>
<para>
For more information, see <xref linkend="ddl-session-variables"/>.
diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index 1ce9abf86f5..683dede6adc 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -515,6 +515,12 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
Plan nodes that reference a correlated <literal>SubPlan</literal>.
</para>
</listitem>
+
+ <listitem>
+ <para>
+ Plan nodes that use a session variable.
+ </para>
+ </listitem>
</itemizedlist>
<sect2 id="parallel-labeling">
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index 78e4983139b..bfbff9ab74e 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -6034,6 +6034,20 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE;
</programlisting>
</para>
</sect3>
+
+ <sect3 id="plpgsql-porting-package-variables">
+ <title><command>Packages and package variables</command></title>
+
+ <para>
+ The <application>PL/pgSQL</application> language has no packages, and
+ therefore no package variables or package constants.
+ You can consider translating an Oracle package into a schema in
+ <productname>PostgreSQL</productname>. Package functions and procedures
+ would then become functions and procedures in that schema, and package
+ variables could be translated to session variables in that schema.
+ (see <xref linkend="ddl-session-variables"/>).
+ </para>
+ </sect3>
</sect2>
<sect2 id="plpgsql-porting-appendix">
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index 2f67de3e21b..cc3bd5ab540 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -158,6 +158,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY grant SYSTEM "grant.sgml">
<!ENTITY importForeignSchema SYSTEM "import_foreign_schema.sgml">
<!ENTITY insert SYSTEM "insert.sgml">
+<!ENTITY let SYSTEM "let.sgml">
<!ENTITY listen SYSTEM "listen.sgml">
<!ENTITY load SYSTEM "load.sgml">
<!ENTITY lock SYSTEM "lock.sgml">
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
index 96d2586423e..221a699469b 100644
--- a/doc/src/sgml/ref/alter_variable.sgml
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -173,6 +173,7 @@ ALTER VARIABLE boo SET SCHEMA private;
<simplelist type="inline">
<member><xref linkend="sql-createvariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
</refentry>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index 6e988f2e472..cd9ff63975a 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -120,9 +120,11 @@ CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceab
<title>Examples</title>
<para>
- Create an date session variable <literal>var1</literal>:
+ Create a session variable <literal>var1</literal> of data type date:
<programlisting>
CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
</programlisting>
</para>
@@ -143,6 +145,7 @@ CREATE VARIABLE var1 AS date;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
index 5bdb3560f0b..67988b5fcd8 100644
--- a/doc/src/sgml/ref/drop_variable.sgml
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -111,6 +111,7 @@ DROP VARIABLE var1;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/let.sgml b/doc/src/sgml/ref/let.sgml
new file mode 100644
index 00000000000..00f9bea91fe
--- /dev/null
+++ b/doc/src/sgml/ref/let.sgml
@@ -0,0 +1,96 @@
+<!--
+doc/src/sgml/ref/let.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-let">
+ <indexterm zone="sql-let">
+ <primary>LET</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>changing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>LET</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>LET</refname>
+ <refpurpose>change a session variable's value</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+LET <replaceable class="parameter">session_variable</replaceable> = <replaceable class="parameter">sql_expression</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>LET</command> command assigns a value to the specified session
+ variable.
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">session_variable</replaceable></term>
+ <listitem>
+ <para>
+ The name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">sql_expression</replaceable></term>
+ <listitem>
+ <para>
+ An arbitrary SQL expression. The result must be of a data type that can
+ be cast to the type of the session variable in an assignment.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+<programlisting>
+CREATE VARIABLE myvar AS integer;
+LET myvar = 10;
+LET myvar = (SELECT sum(val) FROM tab);
+</programlisting>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>LET</command> is a <productname>PostgreSQL</productname>
+ extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index 25578f3946c..13e4adc5df3 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -186,6 +186,7 @@
&grant;
&importForeignSchema;
&insert;
+ &let;
&listen;
&load;
&lock;
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 9e0f648b74f..90c9e8bb254 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1864,6 +1864,11 @@ find_expr_references_walker(Node *node,
{
Param *param = (Param *) node;
+ /* a variable parameter depends on the session variable */
+ if (param->paramkind == PARAM_VARIABLE)
+ add_object_address(VariableRelationId, param->paramvarid, 0,
+ context->addrs);
+
/* A parameter must depend on the parameter's datatype */
add_object_address(TypeRelationId, param->paramtype, 0,
context->addrs);
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 4307cad15c7..beafee2a341 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -3497,6 +3497,295 @@ NamesFromList(List *names)
return result;
}
+/* -----
+ * IdentifyVariable - try to find a variable from a list of identifiers
+ *
+ * Returns the OID of the variable found, or InvalidOid.
+ *
+ * "names" is a list of up to four identifiers; possible meanings are:
+ * - variable (searched on the search_path)
+ * - schema.variable
+ * - variable.attribute (searched on the search_path)
+ * - schema.variable.attribute
+ * - database.schema.variable
+ * - database.schema.variable.attribute
+ *
+ * If there is more than one way to identify a variable, "not_unique" will be
+ * set to true.
+ *
+ * Unless "noerror" is true, an error is raised if there are more than four
+ * identifiers in the list, or if the named database is not the current one.
+ * This is useful if we want to identify a shadowed variable.
+ *
+ * If an attribute is identified, it is stored in "attrname", otherwise the
+ * parameter is set to NULL.
+ *
+ * The identified session variable will be locked with an AccessShareLock.
+ * -----
+ */
+Oid
+IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror)
+{
+ Oid varid = InvalidOid;
+ Oid old_varid = InvalidOid;
+ uint64 inval_count;
+ bool retry = false;
+
+ /*
+ * DDL operations can change the results of a name lookup. Since all such
+ * operations will generate invalidation messages, we keep track of
+ * whether any such messages show up while we're performing the operation,
+ * and retry until either (1) no more invalidation messages show up or (2)
+ * the answer doesn't change.
+ */
+ for (;;)
+ {
+ Node *field1 = NULL;
+ Node *field2 = NULL;
+ Node *field3 = NULL;
+ Node *field4 = NULL;
+ char *a = NULL;
+ char *b = NULL;
+ char *c = NULL;
+ char *d = NULL;
+ Oid varoid_without_attr = InvalidOid;
+ Oid varoid_with_attr = InvalidOid;
+
+ *not_unique = false;
+ *attrname = NULL;
+ varid = InvalidOid;
+
+ inval_count = SharedInvalidMessageCounter;
+
+ switch (list_length(names))
+ {
+ case 1:
+ field1 = linitial(names);
+
+ Assert(IsA(field1, String));
+
+ varid = LookupVariable(NULL, strVal(field1), true);
+ break;
+
+ case 2:
+ field1 = linitial(names);
+ field2 = lsecond(names);
+
+ Assert(IsA(field1, String));
+ a = strVal(field1);
+
+ if (IsA(field2, String))
+ {
+ /* when both fields are of string type */
+ b = strVal(field2);
+
+ /*
+ * a.b can mean "schema"."variable" or
+ * "variable"."attribute". Check both variants, and
+ * returns InvalidOid with not_unique flag, when both
+ * interpretations are possible.
+ */
+ varoid_without_attr = LookupVariable(a, b, true);
+ varoid_with_attr = LookupVariable(NULL, a, true);
+ }
+ else
+ {
+ /* the last field of list can be star too */
+ Assert(IsA(field2, A_Star));
+
+ /*
+ * The syntax ident.* is used only by relation aliases,
+ * and then this identifier cannot be a reference to
+ * session variable.
+ */
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = b;
+ varid = varoid_with_attr;
+ }
+ break;
+
+ case 3:
+ {
+ bool field1_is_catalog = false;
+
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+
+ if (IsA(field3, String))
+ {
+ c = strVal(field3);
+
+ /*
+ * a.b.c can mean catalog.schema.variable or
+ * schema.variable.attribute.
+ *
+ * Check both variants, and set not_unique flag, when
+ * both interpretations are possible.
+ *
+ * When third node is star, only possible
+ * interpretation is schema.variable.*, but this
+ * pattern is not supported now.
+ */
+ varoid_with_attr = LookupVariable(a, b, true);
+
+ /*
+ * check pattern catalog.schema.variable only when
+ * there is possibility to success.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) == 0)
+ {
+ field1_is_catalog = true;
+ varoid_without_attr = LookupVariable(b, c, true);
+ }
+ }
+ else
+ {
+ Assert(IsA(field3, A_Star));
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = c;
+ varid = varoid_with_attr;
+ }
+
+ /*
+ * When we didn't find variable, we can (when it is
+ * allowed) raise cross-database reference error.
+ */
+ if (!OidIsValid(varid) && !noerror && !field1_is_catalog)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+ break;
+
+ case 4:
+ {
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+ field4 = lfourth(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+ Assert(IsA(field3, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+ c = strVal(field3);
+
+ /*
+ * In this case, "a" is used as catalog name - check it.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) != 0)
+ {
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+
+ if (IsA(field4, String))
+ {
+ d = strVal(field4);
+ }
+ else
+ {
+ Assert(IsA(field4, A_Star));
+ return InvalidOid;
+ }
+
+ *attrname = d;
+ varid = LookupVariable(b, c, true);
+ }
+ break;
+
+ default:
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper qualified name (too many dotted names): %s",
+ NameListToString(names))));
+ return InvalidOid;
+ }
+
+ /*
+ * If, upon retry, we get back the same OID we did last time, then the
+ * invalidation messages we processed did not change the final answer.
+ * So we're done.
+ *
+ * If we got a different OID, we've locked the variable that used to
+ * have this name rather than the one that does now. So release the
+ * lock.
+ */
+ if (retry)
+ {
+ if (old_varid == varid)
+ break;
+
+ if (OidIsValid(old_varid))
+ UnlockDatabaseObject(VariableRelationId, old_varid, 0, AccessShareLock);
+ }
+
+ /*
+ * Lock the variable. This will also accept any pending invalidation
+ * messages. If we got back InvalidOid, indicating not found, then
+ * there's nothing to lock, but we accept invalidation messages
+ * anyway, to flush any negative catcache entries that may be
+ * lingering.
+ */
+ if (!OidIsValid(varid))
+ AcceptInvalidationMessages();
+ else
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ /*
+ * If no invalidation message were processed, we're done!
+ */
+ if (inval_count == SharedInvalidMessageCounter)
+ break;
+
+ retry = true;
+ old_varid = varid;
+ varid = InvalidOid;
+ }
+
+ return varid;
+}
+
/*
* DeconstructQualifiedName
* Given a possibly-qualified name expressed as a list of String nodes,
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 29d967a2d5b..bb445e9434b 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -26,6 +26,7 @@
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
+#include "utils/pg_lsn.h"
#include "utils/syscache.h"
static ObjectAddress create_variable(const char *varName,
@@ -101,6 +102,7 @@ create_variable(const char *varName,
varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varcreate_lsn - 1] = LSNGetDatum(GetXLogInsertRecPtr());
values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile
index 48f7348f91c..1cfaeca51ea 100644
--- a/src/backend/commands/Makefile
+++ b/src/backend/commands/Makefile
@@ -50,6 +50,7 @@ OBJS = \
schemacmds.o \
seclabel.o \
sequence.o \
+ session_variable.o \
statscmds.o \
subscriptioncmds.o \
tablecmds.o \
diff --git a/src/backend/commands/meson.build b/src/backend/commands/meson.build
index ef0d407a383..ce1619e3089 100644
--- a/src/backend/commands/meson.build
+++ b/src/backend/commands/meson.build
@@ -38,6 +38,7 @@ backend_sources += files(
'schemacmds.c',
'seclabel.c',
'sequence.c',
+ 'session_variable.c',
'statscmds.c',
'subscriptioncmds.c',
'tablecmds.c',
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 8989c0c882d..902b022f9c7 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -338,6 +338,16 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
i++;
}
+ /*
+ * The arguments of EXECUTE are evaluated by a direct expression
+ * executor call. This mode doesn't support session variables yet.
+ * It will be enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
/* Prepare the expressions for execution */
exprstates = ExecPrepareExprList(params, estate);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
new file mode 100644
index 00000000000..2456a3452b9
--- /dev/null
+++ b/src/backend/commands/session_variable.c
@@ -0,0 +1,529 @@
+/*-------------------------------------------------------------------------
+ *
+ * session_variable.c
+ * session variable creation/manipulation commands
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/commands/session_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "rewrite/rewriteHandler.h"
+#include "storage/lmgr.h"
+#include "storage/proc.h"
+#include "tcop/tcopprot.h"
+#include "utils/builtins.h"
+#include "utils/datum.h"
+#include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/snapmgr.h"
+#include "utils/syscache.h"
+
+/*
+ * The values of session variables are stored in the backend's private memory
+ * in the dedicated memory context SVariableMemoryContext in binary format.
+ * They are stored in the "sessionvars" hash table, whose key is the OID of the
+ * variable. However, the OID is not good enough to identify a session
+ * variable: concurrent sessions could drop the session variable and create a
+ * new one, which could be assigned the same OID. To ensure that the values
+ * stored in memory and the catalog definition match, we also keep track of
+ * the "create_lsn". Before any access to the variable values, we need to
+ * check if the LSN stored in memory matches the LSN in the catalog. If there
+ * is a mismatch between the LSNs, or if the OID is not present in pg_variable
+ * at all, the value stored in memory is released.
+ */
+typedef struct SVariableData
+{
+ Oid varid; /* pg_variable OID of the variable (hash key) */
+ XLogRecPtr create_lsn;
+
+ bool isnull;
+ Datum value;
+
+ Oid typid;
+ int16 typlen;
+ bool typbyval;
+
+ bool is_domain;
+
+ /*
+ * domain_check_extra holds cached domain metadata. This "extra" is
+ * usually stored in fn_mcxt. We do not have access to that memory context
+ * for session variables, but we can use TopTransactionContext instead.
+ * A fresh value is forced when we detect we are in a different transaction
+ * (the local transaction ID differs from domain_check_extra_lxid).
+ */
+ void *domain_check_extra;
+ LocalTransactionId domain_check_extra_lxid;
+
+ /*
+ * Stored value and type description can be outdated when we receive a
+ * sinval message. We then have to check if the stored data are still
+ * trustworthy.
+ */
+ bool is_valid;
+
+ uint32 hashvalue; /* used for pairing sinval message */
+} SVariableData;
+
+typedef SVariableData *SVariable;
+
+static HTAB *sessionvars = NULL; /* hash table for session variables */
+
+static MemoryContext SVariableMemoryContext = NULL;
+
+/*
+ * Callback function for session variable invalidation.
+ */
+static void
+pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
+
+ Assert(sessionvars);
+
+ /*
+ * If the hashvalue is not specified, we have to recheck all currently
+ * used session variables. Since we can't tell the exact session variable
+ * from its hashvalue, we have to iterate over all items in the hash bucket.
+ */
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (hashvalue == 0 || svar->hashvalue == hashvalue)
+ {
+ svar->is_valid = false;
+ }
+ }
+}
+
+/*
+ * Release stored value, free memory
+ */
+static void
+free_session_variable_value(SVariable svar)
+{
+ /* clean the current value */
+ if (!svar->isnull)
+ {
+ if (!svar->typbyval)
+ pfree(DatumGetPointer(svar->value));
+
+ svar->isnull = true;
+ }
+
+ svar->value = (Datum) 0;
+}
+
+/*
+ * Returns true when the entry in pg_variable is consistent with the given
+ * session variable.
+ */
+static bool
+is_session_variable_valid(SVariable svar)
+{
+ HeapTuple tp;
+ bool result = false;
+
+ Assert(OidIsValid(svar->varid));
+
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ /*
+ * The OID alone is not enough as an unique identifier, because OID
+ * values get recycled, and a new session variable could have got
+ * the same OID. We do a second check against the 64-bit LSN when
+ * the variable was created.
+ */
+ if (svar->create_lsn == ((Form_pg_variable) GETSTRUCT(tp))->varcreate_lsn)
+ result = true;
+
+ ReleaseSysCache(tp);
+ }
+
+ return result;
+}
+
+/*
+ * Initialize attributes cached in "svar"
+ */
+static void
+setup_session_variable(SVariable svar, Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ Assert(OidIsValid(varid));
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ svar->varid = varid;
+ svar->create_lsn = varform->varcreate_lsn;
+
+ svar->typid = varform->vartype;
+
+ get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval);
+
+ svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
+ svar->domain_check_extra = NULL;
+ svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+
+ svar->isnull = true;
+ svar->value = (Datum) 0;
+
+ svar->is_valid = true;
+
+ svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ ReleaseSysCache(tup);
+}
+
+/*
+ * Assign a new value to the session variable. It is copied to
+ * SVariableMemoryContext if necessary.
+ *
+ * If any error happens, the existing value won't be modified.
+ */
+static void
+set_session_variable(SVariable svar, Datum value, bool isnull)
+{
+ Datum newval;
+ SVariableData locsvar,
+ *_svar;
+
+ Assert(svar);
+ Assert(!isnull || value == (Datum) 0);
+
+ /*
+ * Use typbyval, typbylen from session variable only when they are
+ * trustworthy (the invalidation message was not accepted for this
+ * variable). If the variable might be invalid, force setup.
+ *
+ * Do not overwrite the passed session variable until we can be certain
+ * that no error can be thrown.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(&locsvar, svar->varid);
+ _svar = &locsvar;
+ }
+ else
+ _svar = svar;
+
+ if (!isnull)
+ {
+ MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
+
+ newval = datumCopy(value, _svar->typbyval, _svar->typlen);
+
+ MemoryContextSwitchTo(oldcxt);
+ }
+ else
+ newval = value;
+
+ free_session_variable_value(svar);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ svar->varid);
+
+ /* no more error expected, so we can overwrite the old variable now */
+ if (svar != _svar)
+ memcpy(svar, _svar, sizeof(SVariableData));
+
+ svar->value = newval;
+ svar->isnull = isnull;
+}
+
+/*
+ * Create the hash table for storing session variables.
+ */
+static void
+create_sessionvars_hashtables(void)
+{
+ HASHCTL vars_ctl;
+
+ Assert(!sessionvars);
+
+ if (!SVariableMemoryContext)
+ {
+ /* read sinval messages */
+ CacheRegisterSyscacheCallback(VARIABLEOID,
+ pg_variable_cache_callback,
+ (Datum) 0);
+
+ /* we need our own long-lived memory context */
+ SVariableMemoryContext =
+ AllocSetContextCreate(TopMemoryContext,
+ "session variables",
+ ALLOCSET_START_SMALL_SIZES);
+ }
+
+ memset(&vars_ctl, 0, sizeof(vars_ctl));
+ vars_ctl.keysize = sizeof(Oid);
+ vars_ctl.entrysize = sizeof(SVariableData);
+ vars_ctl.hcxt = SVariableMemoryContext;
+
+ sessionvars = hash_create("Session variables", 64, &vars_ctl,
+ HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+}
+
+/*
+ * Search a session variable in the hash table given its OID. If it
+ * doesn't exist, then insert it there.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the
+ * session variable until the end of the transaction.
+ */
+static SVariable
+get_session_variable(Oid varid)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect the used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (found)
+ {
+ if (!svar->is_valid)
+ {
+ /*
+ * If there was an invalidation message, the variable might still be
+ * valid, but we have to check with the system catalog.
+ */
+ if (is_session_variable_valid(svar))
+ svar->is_valid = true;
+ else
+ /* if the value cannot be validated, we have to discard it */
+ free_session_variable_value(svar);
+ }
+ }
+ else
+ svar->is_valid = false;
+
+ /*
+ * Force setup for not yet initialized variables or variables that cannot
+ * be validated.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ varid);
+ }
+
+ /* ensure the returned data is still of the correct domain */
+ if (svar->is_domain)
+ {
+ /*
+ * Store "extra" for domain_check() in TopTransactionContext. When we
+ * are in a new transaction, domain_check_extra cache is not valid any
+ * more.
+ */
+ if (svar->domain_check_extra_lxid != MyProc->vxid.lxid)
+ svar->domain_check_extra = NULL;
+
+ domain_check(svar->value, svar->isnull,
+ svar->typid, &svar->domain_check_extra,
+ TopTransactionContext);
+
+ svar->domain_check_extra_lxid = MyProc->vxid.lxid;
+ }
+
+ return svar;
+}
+
+/*
+ * Store the given value in a session variable in the cache.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the session
+ * variable until the end of the transaction.
+ */
+void
+SetSessionVariable(Oid varid, Datum value, bool isNull)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (!found)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ varid);
+ }
+
+ /* if this fails, it won't change the stored value */
+ set_session_variable(svar, value, isNull);
+}
+
+/*
+ * Returns a copy of the value stored in a variable.
+ */
+static inline Datum
+copy_session_variable_value(SVariable svar, bool *isNull)
+{
+ Datum value;
+
+ /* force copy of non NULL value */
+ if (!svar->isnull)
+ {
+ value = datumCopy(svar->value, svar->typbyval, svar->typlen);
+ *isNull = false;
+ }
+ else
+ {
+ value = (Datum) 0;
+ *isNull = true;
+ }
+
+ return value;
+}
+
+/*
+ * Returns a copy of the value of the session variable (in the current memory
+ * context). The caller is responsible for permission checks.
+ */
+Datum
+GetSessionVariable(Oid varid, bool *isNull)
+{
+ SVariable svar;
+
+ svar = get_session_variable(varid);
+
+ /*
+ * Although "svar" is freshly validated in this point, svar->is_valid can
+ * be false, if an invalidation message was processed during the domain check.
+ * But the variable and all its dependencies are locked now, so we don't need
+ * to repeat the validation.
+ */
+ return copy_session_variable_value(svar, isNull);
+}
+
+/*
+ * Assign the result of the evaluated expression to the session variable
+ */
+void
+ExecuteLetStmt(ParseState *pstate,
+ LetStmt *stmt,
+ ParamListInfo params,
+ QueryEnvironment *queryEnv,
+ QueryCompletion *qc)
+{
+ Query *query = castNode(Query, stmt->query);
+ List *rewritten;
+ DestReceiver *dest;
+ AclResult aclresult;
+ PlannedStmt *plan;
+ QueryDesc *queryDesc;
+ Oid varid = query->resultVariable;
+
+ Assert(OidIsValid(varid));
+
+ /* do we have permission to write to the session variable? */
+ aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid));
+
+ /* create a dest receiver for LET */
+ dest = CreateVariableDestReceiver(varid);
+
+ /* run the query rewriter */
+ query = copyObject(query);
+
+ rewritten = QueryRewrite(query);
+
+ Assert(list_length(rewritten) == 1);
+
+ query = linitial_node(Query, rewritten);
+ Assert(query->commandType == CMD_SELECT);
+
+ /* plan the query */
+ plan = pg_plan_query(query, pstate->p_sourcetext,
+ CURSOR_OPT_PARALLEL_OK, params);
+
+ /*
+ * Use a snapshot with an updated command ID to ensure this query sees the
+ * results of any previously executed queries. (This could only matter if
+ * the planner executed an allegedly-stable function that changed the
+ * database contents, but let's do it anyway to be parallel to the EXPLAIN
+ * code path.)
+ */
+ PushCopiedSnapshot(GetActiveSnapshot());
+ UpdateActiveSnapshotCommandId();
+
+ /* create a QueryDesc, redirecting output to our tuple receiver */
+ queryDesc = CreateQueryDesc(plan, pstate->p_sourcetext,
+ GetActiveSnapshot(), InvalidSnapshot,
+ dest, params, queryEnv, 0);
+
+ /* call ExecutorStart to prepare the plan for execution */
+ ExecutorStart(queryDesc, 0);
+
+ /*
+ * Run the plan to completion. The result should be only one row. To
+ * check if there are too many result rows, we try to fetch two.
+ */
+ ExecutorRun(queryDesc, ForwardScanDirection, 2L);
+
+ /* save the rowcount if we're given a QueryCompletion to fill */
+ if (qc)
+ SetQueryCompletion(qc, CMDTAG_LET, queryDesc->estate->es_processed);
+
+ /* and clean up */
+ ExecutorFinish(queryDesc);
+ ExecutorEnd(queryDesc);
+
+ FreeQueryDesc(queryDesc);
+
+ PopActiveSnapshot();
+}
diff --git a/src/backend/executor/Makefile b/src/backend/executor/Makefile
index 11118d0ce02..71248a34f26 100644
--- a/src/backend/executor/Makefile
+++ b/src/backend/executor/Makefile
@@ -76,6 +76,7 @@ OBJS = \
nodeWindowAgg.o \
nodeWorktablescan.o \
spi.o \
+ svariableReceiver.o \
tqueue.o \
tstoreReceiver.o
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 03566c4d181..270e6d344be 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -1041,6 +1041,38 @@ ExecInitExprRec(Expr *node, ExprState *state,
scratch.d.param.paramtype = param->paramtype;
ExprEvalPushStep(state, &scratch);
break;
+
+ case PARAM_VARIABLE:
+ {
+ int es_num_session_variables = 0;
+ SessionVariableValue *es_session_variables = NULL;
+ SessionVariableValue *var;
+
+ if (state->parent && state->parent->state)
+ {
+ es_session_variables = state->parent->state->es_session_variables;
+ es_num_session_variables = state->parent->state->es_num_session_variables;
+ }
+
+ Assert(es_session_variables);
+
+ /* parameter sanity checks */
+ if (param->paramid >= es_num_session_variables)
+ elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
+
+ var = &es_session_variables[param->paramid];
+
+ /*
+ * In this case, pass the value like a
+ * constant.
+ */
+ scratch.opcode = EEOP_CONST;
+ scratch.d.constval.value = var->value;
+ scratch.d.constval.isnull = var->isnull;
+ ExprEvalPushStep(state, &scratch);
+ }
+ break;
+
case PARAM_EXTERN:
/*
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 39d80ccfbad..e51df01c393 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -43,7 +43,9 @@
#include "access/xact.h"
#include "catalog/namespace.h"
#include "catalog/partition.h"
+#include "catalog/pg_variable.h"
#include "commands/matview.h"
+#include "commands/session_variable.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/execPartition.h"
@@ -194,6 +196,70 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
Assert(queryDesc->sourceText != NULL);
estate->es_sourceText = queryDesc->sourceText;
+ /*
+ * The executor doesn't work with session variables directly. Values of
+ * related session variables are copied to a dedicated array, and this array
+ * is passed to the executor. This array is stable "snapshot" of values of
+ * used session variables. There are three benefits of this strategy:
+ *
+ * - consistency with external parameters and plpgsql variables,
+ *
+ * - session variables can be parallel safe,
+ *
+ * - we don't need make fresh copy for any read of session variable
+ * (this is necessary because the internally the session variable can
+ * be changed inside query execution time, and then a reference to
+ * previously returned value can be corrupted).
+ */
+ if (queryDesc->plannedstmt->sessionVariables)
+ {
+ int nSessionVariables;
+ int i = 0;
+
+ /*
+ * In this case, the query uses session variables, but we have to
+ * prepare the array with passed values (of used session variables)
+ * first.
+ */
+ Assert(!IsParallelWorker());
+ nSessionVariables = list_length(queryDesc->plannedstmt->sessionVariables);
+
+ /* create the array used for passing values of used session variables */
+ estate->es_session_variables = (SessionVariableValue *)
+ palloc(nSessionVariables * sizeof(SessionVariableValue));
+
+ /* fill the array */
+ foreach_oid(varid, queryDesc->plannedstmt->sessionVariables)
+ {
+ /*
+ * Permission check should be executed on all explicitly used
+ * variables in the query. For implicitly used variable
+ * (like base node of assignment indirect) we cannot do permission
+ * check, because we need read the value (and user can have
+ * only UPDATE variable). In this case the permission check
+ * is executed in write time.
+ */
+ if (varid != queryDesc->plannedstmt->exclSelectPermCheckVarid)
+ {
+ AclResult aclresult;
+
+ aclresult = object_aclcheck(VariableRelationId, varid,
+ GetUserId(), ACL_SELECT);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE,
+ get_session_variable_name(varid));
+ }
+
+ estate->es_session_variables[i].value =
+ GetSessionVariable(varid,
+ &estate->es_session_variables[i].isnull);
+
+ i++;
+ }
+
+ estate->es_num_session_variables = nSessionVariables;
+ }
+
/*
* Fill in the query environment, if any, from queryDesc.
*/
diff --git a/src/backend/executor/meson.build b/src/backend/executor/meson.build
index 2cea41f8771..491092fcc4c 100644
--- a/src/backend/executor/meson.build
+++ b/src/backend/executor/meson.build
@@ -64,6 +64,7 @@ backend_sources += files(
'nodeWindowAgg.c',
'nodeWorktablescan.c',
'spi.c',
+ 'svariableReceiver.c',
'tqueue.c',
'tstoreReceiver.c',
)
diff --git a/src/backend/executor/svariableReceiver.c b/src/backend/executor/svariableReceiver.c
new file mode 100644
index 00000000000..c6163fb36f6
--- /dev/null
+++ b/src/backend/executor/svariableReceiver.c
@@ -0,0 +1,172 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.c
+ * An implementation of DestReceiver that stores the result value in
+ * a session variable.
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/executor/svariableReceiver.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "miscadmin.h"
+
+#include "access/detoast.h"
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "storage/lock.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+/*
+ * This DestReceiver is used by the LET command for storing the result to a
+ * session variable. The result has to have only one tuple with only one
+ * non-deleted attribute. The row counter (field "rows") is incremented
+ * after receiving a row, and an error is raised when there are no rows or
+ * there are more than one received rows. A received tuple cannot to have
+ * deleted attributes. The value is detoasted before storing it in the
+ * session variable.
+ */
+typedef struct
+{
+ DestReceiver pub;
+ Oid varid;
+ bool need_detoast; /* do we need to detoast the attribute? */
+ int rows; /* row counter */
+} SVariableState;
+
+/*
+ * Prepare to receive tuples from executor.
+ */
+static void
+svariableStartupReceiver(DestReceiver *self, int operation, TupleDesc typeinfo)
+{
+ SVariableState *myState = (SVariableState *) self;
+ LOCKTAG locktag PG_USED_FOR_ASSERTS_ONLY;
+ Form_pg_attribute attr;
+ Oid typid PG_USED_FOR_ASSERTS_ONLY;
+ Oid collid PG_USED_FOR_ASSERTS_ONLY;
+ int32 typmod PG_USED_FOR_ASSERTS_ONLY;
+
+ Assert(myState->pub.mydest == DestVariable);
+ Assert(OidIsValid(myState->varid));
+ Assert(SearchSysCacheExists1(VARIABLEOID, myState->varid));
+ Assert(typeinfo->natts == 1);
+
+#ifdef USE_ASSERT_CHECKING
+
+ SET_LOCKTAG_OBJECT(locktag,
+ MyDatabaseId,
+ VariableRelationId,
+ myState->varid,
+ 0);
+
+ Assert(LockHeldByMe(&locktag, AccessShareLock, false));
+
+#endif
+
+ attr = TupleDescAttr(typeinfo, 0);
+
+ Assert(!attr->attisdropped);
+
+#ifdef USE_ASSERT_CHECKING
+
+ get_session_variable_type_typmod_collid(myState->varid,
+ &typid,
+ &typmod,
+ &collid);
+
+ Assert(attr->atttypid == typid);
+ Assert(attr->atttypmod < 0 || attr->atttypmod == typmod);
+
+#endif
+
+ myState->need_detoast = attr->attlen == -1;
+ myState->rows = 0;
+}
+
+/*
+ * Receive a tuple from the executor and store it in the session variable.
+ */
+static bool
+svariableReceiveSlot(TupleTableSlot *slot, DestReceiver *self)
+{
+ SVariableState *myState = (SVariableState *) self;
+ Datum value;
+ bool isnull;
+ bool freeval = false;
+
+ /* make sure the tuple is fully deconstructed */
+ slot_getallattrs(slot);
+
+ value = slot->tts_values[0];
+ isnull = slot->tts_isnull[0];
+
+ if (myState->need_detoast && !isnull && VARATT_IS_EXTERNAL(DatumGetPointer(value)))
+ {
+ value = PointerGetDatum(detoast_external_attr((struct varlena *)
+ DatumGetPointer(value)));
+ freeval = true;
+ }
+
+ myState->rows += 1;
+
+ if (myState->rows > 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_TOO_MANY_ROWS),
+ errmsg("expression returned more than one row")));
+
+ SetSessionVariable(myState->varid, value, isnull);
+
+ if (freeval)
+ pfree(DatumGetPointer(value));
+
+ return true;
+}
+
+/*
+ * Clean up at end of the executor run
+ */
+static void
+svariableShutdownReceiver(DestReceiver *self)
+{
+ if (((SVariableState *) self)->rows == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_NO_DATA_FOUND),
+ errmsg("expression returned no rows")));
+}
+
+/*
+ * Destroy the receiver when we are done with it
+ */
+static void
+svariableDestroyReceiver(DestReceiver *self)
+{
+ pfree(self);
+}
+
+/*
+ * Initially create a DestReceiver object.
+ */
+DestReceiver *
+CreateVariableDestReceiver(Oid varid)
+{
+ SVariableState *self = (SVariableState *) palloc0(sizeof(SVariableState));
+
+ self->pub.receiveSlot = svariableReceiveSlot;
+ self->pub.rStartup = svariableStartupReceiver;
+ self->pub.rShutdown = svariableShutdownReceiver;
+ self->pub.rDestroy = svariableDestroyReceiver;
+ self->pub.mydest = DestVariable;
+
+ self->varid = varid;
+
+ return (DestReceiver *) self;
+}
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f1..d8fc3d9fa69 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4375,6 +4375,16 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_LetStmt:
+ {
+ LetStmt *stmt = (LetStmt *) node;
+
+ if (WALK(stmt->target))
+ return true;
+ if (WALK(stmt->query))
+ return true;
+ }
+ break;
case T_PLAssignStmt:
{
PLAssignStmt *stmt = (PLAssignStmt *) node;
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 7b1a8a0a9f1..cf094987569 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -333,6 +333,21 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
glob->lastPlanNodeId = 0;
glob->transientPlan = false;
glob->dependsOnRole = false;
+ glob->sessionVariables = NIL;
+
+ /*
+ * The (session) result variable should be stored to global, because
+ * it is not set in subquery. When this variable is used other than
+ * in base node of assignment indirection, we need to check the access
+ * rights (and then we need to detect this situation). The variable used
+ * like base node cannot be different than target (result) variable.
+ * Because we know the result variable before planner invocation, we
+ * can simply search of usage just this variable, and we don't need to
+ * to wait until the end of planning when we know basenodeSessionVarid.
+ */
+ glob->resultVariable = parse->resultVariable;
+ glob->basenodeSessionVarid = InvalidOid;
+ glob->basenodeSessionVarSelectCheck = false;
/*
* Assess whether it's feasible to use parallel mode for this query. We
@@ -570,6 +585,20 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
result->paramExecTypes = glob->paramExecTypes;
/* utilityStmt should be null, but we might as well copy it */
result->utilityStmt = parse->utilityStmt;
+
+ result->sessionVariables = glob->sessionVariables;
+
+ /*
+ * The session variable used (and only used) like base node
+ * for assignemnt indirection should be excluded from permission
+ * check.
+ */
+ if (OidIsValid(glob->basenodeSessionVarid) &&
+ (!glob->basenodeSessionVarSelectCheck))
+ result->exclSelectPermCheckVarid = glob->basenodeSessionVarid;
+ else
+ result->exclSelectPermCheckVarid = InvalidOid;
+
result->stmt_location = parse->stmt_location;
result->stmt_len = parse->stmt_len;
@@ -740,6 +769,13 @@ subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root,
*/
pull_up_subqueries(root);
+ /*
+ * Check if some subquery uses a session variable. The flag
+ * hasSessionVariables should be true if the query or some subquery uses a
+ * session variable.
+ */
+ pull_up_has_session_variables(root);
+
/*
* If this is a simple UNION ALL query, flatten it into an appendrel. We
* do this now because it requires applying pull_up_subqueries to the leaf
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 999a5a8ab5a..dc2caa520f7 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -210,6 +210,9 @@ static List *set_returning_clause_references(PlannerInfo *root,
static List *set_windowagg_runcondition_references(PlannerInfo *root,
List *runcondition,
Plan *plan);
+static bool pull_up_has_session_variables_walker(Node *node,
+ PlannerInfo *root);
+static void record_plan_variable_dependency(PlannerInfo *root, Oid varid);
/*****************************************************************************
@@ -1315,6 +1318,50 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
return plan;
}
+/*
+ * Search usage of session variables in subqueries
+ */
+void
+pull_up_has_session_variables(PlannerInfo *root)
+{
+ Query *query = root->parse;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ }
+ else
+ {
+ (void) query_tree_walker(query,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+}
+
+static bool
+pull_up_has_session_variables_walker(Node *node, PlannerInfo *root)
+{
+ if (node == NULL)
+ return false;
+ if (IsA(node, Query))
+ {
+ Query *query = (Query *) node;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ return false;
+ }
+
+ /* recurse into subselects */
+ return query_tree_walker((Query *) node,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+ return expression_tree_walker(node, pull_up_has_session_variables_walker,
+ (void *) root);
+}
+
/*
* set_indexonlyscan_references
* Do set_plan_references processing on an IndexOnlyScan
@@ -2015,8 +2062,9 @@ copyVar(Var *var)
* This is code that is common to all variants of expression-fixing.
* We must look up operator opcode info for OpExpr and related nodes,
* add OIDs from regclass Const nodes into root->glob->relationOids, and
- * add PlanInvalItems for user-defined functions into root->glob->invalItems.
- * We also fill in column index lists for GROUPING() expressions.
+ * add PlanInvalItems for user-defined functions and session variables into
+ * root->glob->invalItems. We also fill in column index lists for GROUPING()
+ * expressions.
*
* We assume it's okay to update opcode info in-place. So this could possibly
* scribble on the planner's input data structures, but it's OK.
@@ -2106,6 +2154,13 @@ fix_expr_common(PlannerInfo *root, Node *node)
g->cols = cols;
}
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ record_plan_variable_dependency(root, p->paramvarid);
+ }
}
/*
@@ -2115,6 +2170,10 @@ fix_expr_common(PlannerInfo *root, Node *node)
* If it's a PARAM_MULTIEXPR, replace it with the appropriate Param from
* root->multiexpr_params; otherwise no change is needed.
* Just for paranoia's sake, we make a copy of the node in either case.
+ *
+ * If it's a PARAM_VARIABLE, then we collect used session variables in
+ * the list root->glob->sessionVariable. Also, assign the parameter's
+ * "paramid" to the parameter's position in that list.
*/
static Node *
fix_param_node(PlannerInfo *root, Param *p)
@@ -2133,6 +2192,62 @@ fix_param_node(PlannerInfo *root, Param *p)
elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid);
return copyObject(list_nth(params, colno - 1));
}
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ int n = 0;
+ bool found = false;
+
+ /* we will modify object */
+ p = (Param *) copyObject(p);
+
+ /*
+ * Now, we can actualize list of session variables, and we can
+ * complete paramid parameter.
+ */
+ foreach_oid(varid, root->glob->sessionVariables)
+ {
+ if (varid == p->paramvarid)
+ {
+ p->paramid = n;
+ found = true;
+ break;
+ }
+ n += 1;
+ }
+
+ if (!found)
+ {
+ root->glob->sessionVariables = lappend_oid(root->glob->sessionVariables,
+ p->paramvarid);
+ p->paramid = n;
+ }
+
+ /*
+ * We do SELECT permission check of all variables used by
+ * the query excluding the variable that is used only as base node
+ * of assignment indirection. The variable id assigned to this param
+ * should be same like resultVariable id, and this param should be
+ * used only once in query. When the variable is referenced by any
+ * other param, we should to do SELECT permission check for this variable
+ * too.
+ */
+ if (p->parambasenode)
+ {
+ Assert(!OidIsValid(root->glob->basenodeSessionVarid));
+ Assert(root->glob->resultVariable == p->paramvarid);
+
+ root->glob->basenodeSessionVarid = p->paramvarid;
+ }
+ else
+ {
+ if (p->paramvarid == root->glob->resultVariable)
+ root->glob->basenodeSessionVarSelectCheck = true;
+ }
+
+ return (Node *) p;
+ }
+
return (Node *) copyObject(p);
}
@@ -2194,7 +2309,10 @@ fix_alternative_subplan(PlannerInfo *root, AlternativeSubPlan *asplan,
* replacing Aggref nodes that should be replaced by initplan output Params,
* choosing the best implementation for AlternativeSubPlans,
* looking up operator opcode info for OpExpr and related nodes,
- * and adding OIDs from regclass Const nodes into root->glob->relationOids.
+ * adding OIDs from regclass Const nodes into root->glob->relationOids,
+ * assigning paramvarid to PARAM_VARIABLE params, and collecting the
+ * OIDs of session variables in the root->glob->sessionVariables list
+ * (paramvarid is the position of the session variable in this list).
*
* 'node': the expression to be modified
* 'rtoffset': how much to increment varnos by
@@ -2216,7 +2334,8 @@ fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec)
root->multiexpr_params != NIL ||
root->glob->lastPHId != 0 ||
root->minmax_aggs != NIL ||
- root->hasAlternativeSubPlans)
+ root->hasAlternativeSubPlans ||
+ root->hasSessionVariables)
{
return fix_scan_expr_mutator(node, &context);
}
@@ -3609,6 +3728,25 @@ record_plan_type_dependency(PlannerInfo *root, Oid typid)
}
}
+/*
+ * Record dependency on a session variable. The variable can be used as a
+ * session variable in an expression list, or as the target of a LET statement.
+ */
+static void
+record_plan_variable_dependency(PlannerInfo *root, Oid varid)
+{
+ PlanInvalItem *inval_item = makeNode(PlanInvalItem);
+
+ /* paramid is still session variable id */
+ inval_item->cacheId = VARIABLEOID;
+ inval_item->hashValue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ /* append this variable to global, register dependency */
+ root->glob->invalItems = lappend(root->glob->invalItems,
+ inval_item);
+}
+
/*
* extract_query_dependencies
* Given a rewritten, but not yet planned, query or queries
@@ -3694,9 +3832,9 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
}
/*
- * Ignore other utility statements, except those (such as EXPLAIN)
- * that contain a parsed-but-not-planned query. For those, we
- * just need to transfer our attention to the contained query.
+ * Ignore other utility statements, except those (such as EXPLAIN
+ * or LET) that contain a parsed-but-not-planned query. For those,
+ * we just need to transfer our attention to the contained query.
*/
query = UtilityContainsQuery(query->utilityStmt);
if (query == NULL)
@@ -3719,6 +3857,10 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
lappend_oid(context->glob->relationOids, rte->relid);
}
+ /* record dependency on the target variable of a LET command */
+ if (OidIsValid(query->resultVariable))
+ record_plan_variable_dependency(context, query->resultVariable);
+
/* And recurse into the query's subexpressions */
return query_tree_walker(query, extract_query_dependencies_walker,
context, 0);
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index 5d9225e9909..71479ceb1bc 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -1432,6 +1432,9 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
/* If subquery had any RLS conditions, now main query does too */
parse->hasRowSecurity |= subquery->hasRowSecurity;
+ /* if the subquery had session variables, the main query does too */
+ parse->hasSessionVariables |= subquery->hasSessionVariables;
+
/*
* subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
* hasTargetSRFs, so no work needed on those flags
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 43dfecfb47f..f60828f862e 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -24,6 +24,7 @@
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "commands/session_variable.h"
#include "executor/executor.h"
#include "executor/functions.h"
#include "funcapi.h"
@@ -934,6 +935,13 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
if (param->paramkind == PARAM_EXTERN)
return false;
+ /* we don't support passing session variables to workers */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
+ return true;
+ }
+
if (param->paramkind != PARAM_EXEC ||
!list_member_int(context->safe_param_ids, param->paramid))
{
@@ -2389,6 +2397,7 @@ convert_saop_to_hashed_saop_walker(Node *node, void *context)
* value of the Param.
* 2. Fold stable, as well as immutable, functions to constants.
* 3. Reduce PlaceHolderVar nodes to their contained expressions.
+ * 4. Current value of session variable can be used for estimation too.
*--------------------
*/
Node *
@@ -2515,6 +2524,27 @@ eval_const_expressions_mutator(Node *node,
}
}
}
+ else if (param->paramkind == PARAM_VARIABLE &&
+ context->estimate)
+ {
+ int16 typLen;
+ bool typByVal;
+ Datum pval;
+ bool isnull;
+
+ get_typlenbyval(param->paramtype,
+ &typLen, &typByVal);
+
+ pval = GetSessionVariable(param->paramvarid, &isnull);
+
+ return (Node *) makeConst(param->paramtype,
+ param->paramtypmod,
+ param->paramcollid,
+ (int) typLen,
+ pval,
+ isnull,
+ typByVal);
+ }
/*
* Not replaceable, so just copy the Param (no need to
@@ -4720,7 +4750,8 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
querytree->limitOffset ||
querytree->limitCount ||
querytree->setOperations ||
- list_length(querytree->targetList) != 1)
+ (list_length(querytree->targetList) != 1) ||
+ querytree->hasSessionVariables)
goto fail;
/* If the function result is composite, resolve it */
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 76f58b3aca3..725f678e2fa 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -25,9 +25,12 @@
#include "postgres.h"
#include "access/sysattr.h"
+#include "catalog/namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
@@ -51,6 +54,7 @@
#include "utils/backend_status.h"
#include "utils/builtins.h"
#include "utils/guc.h"
+#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
@@ -83,6 +87,8 @@ static Query *transformCreateTableAsStmt(ParseState *pstate,
CreateTableAsStmt *stmt);
static Query *transformCallStmt(ParseState *pstate,
CallStmt *stmt);
+static Query *transformLetStmt(ParseState *pstate,
+ LetStmt *stmt);
static void transformLockingClause(ParseState *pstate, Query *qry,
LockingClause *lc, bool pushedDown);
#ifdef DEBUG_NODE_TESTS_ENABLED
@@ -414,6 +420,7 @@ transformStmt(ParseState *pstate, Node *parseTree)
case T_UpdateStmt:
case T_DeleteStmt:
case T_MergeStmt:
+ case T_LetStmt:
(void) test_raw_expression_coverage(parseTree, NULL);
break;
default:
@@ -493,6 +500,11 @@ transformStmt(ParseState *pstate, Node *parseTree)
(CallStmt *) parseTree);
break;
+ case T_LetStmt:
+ result = transformLetStmt(pstate,
+ (LetStmt *) parseTree);
+ break;
+
default:
/*
@@ -545,6 +557,7 @@ stmt_requires_parse_analysis(RawStmt *parseTree)
case T_SelectStmt:
case T_ReturnStmt:
case T_PLAssignStmt:
+ case T_LetStmt:
result = true;
break;
@@ -653,6 +666,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1078,6 +1092,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1543,6 +1558,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, stmt->lockingClause)
{
@@ -1769,12 +1785,241 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
return qry;
}
+/*
+ * transformLetStmt -
+ * transform an Let Statement
+ */
+static Query *
+transformLetStmt(ParseState *pstate, LetStmt *stmt)
+{
+ Query *query;
+ Query *result;
+ List *exprList = NIL;
+ List *exprListCoer = NIL;
+ ListCell *lc;
+ ListCell *indirection_head = NULL;
+ Query *selectQuery;
+ Oid varid;
+ char *attrname = NULL;
+ bool not_unique;
+ bool is_rowtype;
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+ List *names = NULL;
+ int indirection_start;
+ int i = 0;
+
+ /* there can't be any outer WITH to worry about */
+ Assert(pstate->p_ctenamespace == NIL);
+
+ names = NamesFromList(stmt->target);
+
+ /* locks the variable with an AccessShareLock */
+ varid = IdentifyVariable(names, &attrname, ¬_unique, false);
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("target \"%s\" of LET command is ambiguous",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ if (!OidIsValid(varid))
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ /*
+ * Calculate start of possible position of an indirection in list, and
+ * when it is inside the list, store pointer on first node of indirection.
+ */
+ indirection_start = list_length(names) - (attrname ? 1 : 0);
+ if (list_length(stmt->target) > indirection_start)
+ indirection_head = list_nth_cell(stmt->target, indirection_start);
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod, &collid);
+
+ is_rowtype = type_is_rowtype(typid);
+
+ if (attrname && !is_rowtype)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("cannot assign to field \"%s\" of session variable \"%s.%s\" because its type %s is not a composite type",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->location)));
+
+ pstate->p_expr_kind = EXPR_KIND_LET_TARGET;
+
+ /* we need to postpone conversion of "unknown" to text */
+ pstate->p_resolve_unknowns = false;
+
+ selectQuery = transformStmt(pstate, stmt->query);
+
+ /* the grammar should have produced a SELECT */
+ Assert(IsA(selectQuery, Query) && selectQuery->commandType == CMD_SELECT);
+
+ /*
+ * Generate an expression list for the LET that selects all the non-resjunk
+ * columns from the subquery.
+ */
+ exprList = NIL;
+ foreach_node(TargetEntry, tle, selectQuery->targetList)
+ {
+ if (tle->resjunk)
+ continue;
+
+ exprList = lappend(exprList, tle->expr);
+ }
+
+ /* don't allow multicolumn result */
+ if (list_length(exprList) != 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg_plural("assignment expression returned %d column",
+ "assignment expression returned %d columns",
+ list_length(exprList),
+ list_length(exprList)),
+ parser_errposition(pstate,
+ exprLocation((Node *) exprList))));
+
+ exprListCoer = NIL;
+
+ foreach(lc, exprList)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ Expr *coerced_expr;
+ Oid exprtypid;
+
+ /* now we can read the type of the expression */
+ exprtypid = exprType((Node *) expr);
+
+ if (indirection_head)
+ {
+ bool targetIsArray;
+ char *targetName;
+ Param *param;
+
+ targetName = get_session_variable_name(varid);
+ targetIsArray = OidIsValid(get_element_type(typid));
+
+ pstate->p_hasSessionVariables = true;
+
+ param = makeNode(Param);
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+
+ /*
+ * The parameter used as basenode has to have special
+ * mark, because requires special access when we do
+ * SELECT access check.
+ */
+ param->parambasenode = true;
+
+ coerced_expr = (Expr *)
+ transformAssignmentIndirection(pstate,
+ (Node *) param,
+ targetName,
+ targetIsArray,
+ typid,
+ typmod,
+ InvalidOid,
+ stmt->target,
+ indirection_head,
+ (Node *) expr,
+ COERCION_ASSIGNMENT,
+ stmt->location);
+ }
+ else
+ coerced_expr = (Expr *)
+ coerce_to_target_type(pstate,
+ (Node *) expr,
+ exprtypid,
+ typid, typmod,
+ COERCION_ASSIGNMENT,
+ COERCE_IMPLICIT_CAST,
+ stmt->location);
+
+ if (coerced_expr == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("variable \"%s.%s\" is of type %s, but expression is of type %s",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid),
+ format_type_be(exprtypid)),
+ errhint("You will need to rewrite or cast the expression."),
+ parser_errposition(pstate, exprLocation((Node *) expr))));
+
+ exprListCoer = lappend(exprListCoer, coerced_expr);
+ }
+
+ /* generate query's target list using the computed list of expressions */
+ query = makeNode(Query);
+ query->commandType = CMD_SELECT;
+
+ foreach(lc, exprListCoer)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ TargetEntry *tle;
+
+ tle = makeTargetEntry(expr,
+ i + 1,
+ FigureColname((Node *) expr),
+ false);
+ query->targetList = lappend(query->targetList, tle);
+ }
+
+ /* done building the range table and jointree */
+ query->rtable = pstate->p_rtable;
+ query->jointree = makeFromExpr(pstate->p_joinlist, NULL);
+
+ query->hasTargetSRFs = pstate->p_hasTargetSRFs;
+ query->hasSubLinks = pstate->p_hasSubLinks;
+ query->hasSessionVariables = pstate->p_hasSessionVariables;
+
+ /* this is top-level query */
+ query->canSetTag = true;
+
+ /*
+ * Save target session variable ID. It is used later for
+ * acquiring an AccessShareLock on target variable, setting
+ * plan dependency and finally for creating VariableDestReceiver.
+ */
+ query->resultVariable = varid;
+
+ assign_query_collations(pstate, query);
+
+ /*
+ * The query is executed as utility command by nested executor call.
+ * Assigned queryId is required in this case.
+ */
+ if (IsQueryIdEnabled())
+ JumbleQuery(query);
+
+ stmt->query = (Node *) query;
+
+ /* represent the command as a utility Query */
+ result = makeNode(Query);
+ result->commandType = CMD_UTILITY;
+ result->utilityStmt = (Node *) stmt;
+
+ return result;
+}
+
/*
* transformSetOperationStmt -
* transforms a set-operations tree
@@ -2020,6 +2265,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, lockingClause)
{
@@ -2495,6 +2741,7 @@ transformReturnStmt(ParseState *pstate, ReturnStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2562,6 +2809,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2852,9 +3100,15 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
/*
* Transform the target reference. Typically we will get back a Param
* node, but there's no reason to be too picky about its type.
+ *
+ * Session variables should not be used as target of a PL/pgSQL assign
+ * statement. So we should use a dedicated expression kind and disallow
+ * session variables there. The dedicated context allows to eliminate
+ * undesirable warnings about the possibility of a target PL/pgSQL variable
+ * shadowing a session variable.
*/
target = transformExpr(pstate, (Node *) cref,
- EXPR_KIND_UPDATE_TARGET);
+ EXPR_KIND_ASSIGN_TARGET);
targettype = exprType(target);
targettypmod = exprTypmod(target);
targetcollation = exprCollation(target);
@@ -2896,6 +3150,10 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
*/
type_id = exprType((Node *) tle->expr);
+ /*
+ * For indirection processing and additional casts we can use expr_kind
+ * EXPR_KIND_UPDATE_TARGET.
+ */
pstate->p_expr_kind = EXPR_KIND_UPDATE_TARGET;
if (indirection)
@@ -3038,6 +3296,8 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
(LockingClause *) lfirst(l), false);
}
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
+
assign_query_collations(pstate, qry);
/* this must be done after collations, for reliable comparison of exprs */
@@ -3311,6 +3571,16 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt)
true,
stmt->funccall->location);
+ /*
+ * The arguments of CALL statement are evaluated by a direct expression
+ * executor call. This path is unsupported yet, so block it. It will be
+ * enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
assign_expr_collations(pstate, node);
fexpr = castNode(FuncExpr, node);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 2de2022b281..d34ea39bc83 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -297,7 +297,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
DropTransformStmt
DropUserMappingStmt ExplainStmt FetchStmt
GrantStmt GrantRoleStmt ImportForeignSchemaStmt IndexStmt InsertStmt
- ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
+ LetStmt ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
CreateFunctionStmt AlterFunctionStmt ReindexStmt RemoveAggrStmt
RemoveFuncStmt RemoveOperStmt RenameStmt ReturnStmt RevokeStmt RevokeRoleStmt
RuleActionStmt RuleActionStmtOrEmpty RuleStmt
@@ -742,7 +742,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
KEEP KEY KEYS
LABEL LANGUAGE LARGE_P LAST_P LATERAL_P
- LEADING LEAKPROOF LEAST LEFT LEVEL LIKE LIMIT LISTEN LOAD LOCAL
+ LEADING LEAKPROOF LEAST LEFT LET LEVEL LIKE LIMIT LISTEN LOAD LOCAL
LOCALTIME LOCALTIMESTAMP LOCATION LOCK_P LOCKED LOGGED
MAPPING MATCH MATCHED MATERIALIZED MAXVALUE MERGE MERGE_ACTION METHOD
@@ -1089,6 +1089,7 @@ stmt:
| ImportForeignSchemaStmt
| IndexStmt
| InsertStmt
+ | LetStmt
| ListenStmt
| RefreshMatViewStmt
| LoadStmt
@@ -12845,6 +12846,38 @@ opt_hold: /* EMPTY */ { $$ = 0; }
| WITHOUT HOLD { $$ = 0; }
;
+/*****************************************************************************
+ *
+ * QUERY:
+ * LET STATEMENT
+ *
+ *****************************************************************************/
+LetStmt: LET ColId opt_indirection '=' a_expr
+ {
+ LetStmt *n = makeNode(LetStmt);
+ SelectStmt *select;
+ ResTarget *res;
+
+ n->target = lcons(makeString($2),
+ check_indirection($3, yyscanner));
+
+ select = makeNode(SelectStmt);
+ res = makeNode(ResTarget);
+
+ /* create target list for implicit query */
+ res->name = NULL;
+ res->indirection = NIL;
+ res->val = (Node *) $5;
+ res->location = @5;
+
+ select->targetList = list_make1(res);
+ n->query = (Node *) select;
+
+ n->location = @2;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* QUERY:
@@ -17916,6 +17949,7 @@ unreserved_keyword:
| LARGE_P
| LAST_P
| LEAKPROOF
+ | LET
| LEVEL
| LISTEN
| LOAD
@@ -18529,6 +18563,7 @@ bare_label_keyword:
| LEAKPROOF
| LEAST
| LEFT
+ | LET
| LEVEL
| LIKE
| LISTEN
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 9e567f3cc45..4737b04d171 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -580,6 +580,11 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
+
/*
* There is intentionally no default: case here, so that the
* compiler will warn if we add a new ParseExprKind without
@@ -970,6 +975,10 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
case EXPR_KIND_CYCLE_MARK:
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index bad1df732ea..4f208c7efdd 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -17,6 +17,7 @@
#include "catalog/pg_aggregate.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
@@ -33,11 +34,13 @@
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "parser/parse_type.h"
+#include "storage/lmgr.h"
#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/timestamp.h"
+#include "utils/typcache.h"
#include "utils/xml.h"
/* GUC parameters */
@@ -106,6 +109,9 @@ static Expr *make_distinct_op(ParseState *pstate, List *opname,
Node *ltree, Node *rtree, int location);
static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
+static Node *makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location);
/*
@@ -499,6 +505,89 @@ transformIndirection(ParseState *pstate, A_Indirection *ind)
return result;
}
+/*
+ * Returns true if the given expression kind is valid for session variables.
+ * Session variables can be used everywhere where external parameters can be
+ * used. Session variables are not allowed in DDL commands or in constraints.
+ *
+ * An identifier can be parsed as a session variable only for expression kinds
+ * where session variables are allowed. This is the primary usage of this
+ * function.
+ *
+ * The second usage of this function is to decide whether a "column does not
+ * exist" or a "column or variable does not exist" error message should be
+ * printed. When we are in an expression where session variables cannot be
+ * used, we raise the first form of error message.
+ */
+static bool
+expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
+{
+ bool result = false;
+
+ switch (p_expr_kind)
+ {
+ case EXPR_KIND_NONE:
+ Assert(false); /* can't happen */
+ return false;
+
+ /* session variables allowed */
+ case EXPR_KIND_OTHER:
+ case EXPR_KIND_JOIN_ON:
+ case EXPR_KIND_FROM_SUBSELECT:
+ case EXPR_KIND_FROM_FUNCTION:
+ case EXPR_KIND_WHERE:
+ case EXPR_KIND_HAVING:
+ case EXPR_KIND_FILTER:
+ case EXPR_KIND_WINDOW_PARTITION:
+ case EXPR_KIND_WINDOW_ORDER:
+ case EXPR_KIND_WINDOW_FRAME_RANGE:
+ case EXPR_KIND_WINDOW_FRAME_ROWS:
+ case EXPR_KIND_WINDOW_FRAME_GROUPS:
+ case EXPR_KIND_SELECT_TARGET:
+ case EXPR_KIND_INSERT_TARGET:
+ case EXPR_KIND_UPDATE_SOURCE:
+ case EXPR_KIND_UPDATE_TARGET:
+ case EXPR_KIND_MERGE_WHEN:
+ case EXPR_KIND_MERGE_RETURNING:
+ case EXPR_KIND_GROUP_BY:
+ case EXPR_KIND_ORDER_BY:
+ case EXPR_KIND_DISTINCT_ON:
+ case EXPR_KIND_LIMIT:
+ case EXPR_KIND_OFFSET:
+ case EXPR_KIND_RETURNING:
+ case EXPR_KIND_VALUES:
+ case EXPR_KIND_VALUES_SINGLE:
+ case EXPR_KIND_ALTER_COL_TRANSFORM:
+ case EXPR_KIND_EXECUTE_PARAMETER:
+ case EXPR_KIND_POLICY:
+ case EXPR_KIND_CALL_ARGUMENT:
+ case EXPR_KIND_COPY_WHERE:
+ case EXPR_KIND_LET_TARGET:
+ result = true;
+ break;
+
+ /* session variables not allowed */
+ case EXPR_KIND_CHECK_CONSTRAINT:
+ case EXPR_KIND_DOMAIN_CHECK:
+ case EXPR_KIND_COLUMN_DEFAULT:
+ case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_INDEX_EXPRESSION:
+ case EXPR_KIND_INDEX_PREDICATE:
+ case EXPR_KIND_STATS_EXPRESSION:
+ case EXPR_KIND_TRIGGER_WHEN:
+ case EXPR_KIND_PARTITION_BOUND:
+ case EXPR_KIND_PARTITION_EXPRESSION:
+ case EXPR_KIND_GENERATED_COLUMN:
+ case EXPR_KIND_JOIN_USING:
+ case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ result = false;
+ break;
+ }
+
+ return result;
+}
+
/*
* Transform a ColumnRef.
*
@@ -575,6 +664,8 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
case EXPR_KIND_COPY_WHERE:
case EXPR_KIND_GENERATED_COLUMN:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
@@ -847,8 +938,61 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
}
/*
- * Throw error if no translation found.
+ * There are contexts where session variables are not allowed. We don't
+ * need to identify session variables in such a context, but identifying
+ * them allows us to raise meaningful error messages like "you cannot use
+ * session variables here".
*/
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind))
+ {
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* -----
+ * Session variables are shadowed by columns, routine variables or
+ * routine arguments. We certainly don't want to use a session variable
+ * when it is exactly shadowed, but a RTE like this is conceivable:
+ *
+ * CREATE TYPE t AS (c int);
+ * CREATE VARIABLE foo AS t;
+ * CREATE TABLE foo(a int, b int);
+ *
+ * SELECT foo.a, foo.b, foo.c FROM foo;
+ *
+ * However, that is very confusing, so we disallow it. We don't try to
+ * identify a variable if we know that it would be shadowed.
+ * -----
+ */
+ if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ {
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(cref->fields)),
+ parser_errposition(pstate, cref->location)));
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ node = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, cref->location);
+ }
+ }
+ }
+
+ /* throw an error if no translation was found */
if (node == NULL)
{
switch (crerr)
@@ -880,6 +1024,75 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
return node;
}
+/*
+ * Generate param variable for reference to session variable
+ */
+static Node *
+makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location)
+{
+ Param *param;
+
+ param = makeNode(Param);
+
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+ param->paramcollid = collid;
+
+ pstate->p_hasSessionVariables = true;
+
+ if (attrname != NULL)
+ {
+ TupleDesc tupdesc;
+ int i;
+
+ tupdesc = lookup_rowtype_tupdesc_noerror(typid, typmod, true);
+ if (!tupdesc)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("variable \"%s.%s\" is of type \"%s\", which is not a composite type",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, location)));
+
+ for (i = 0; i < tupdesc->natts; i++)
+ {
+ Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+ if (strcmp(attrname, NameStr(att->attname)) == 0 &&
+ !att->attisdropped)
+ {
+ /* success, so generate a FieldSelect expression */
+ FieldSelect *fselect = makeNode(FieldSelect);
+
+ fselect->arg = (Expr *) param;
+ fselect->fieldnum = i + 1;
+ fselect->resulttype = att->atttypid;
+ fselect->resulttypmod = att->atttypmod;
+ /* save attribute's collation for parse_collate.c */
+ fselect->resultcollid = att->attcollation;
+
+ ReleaseTupleDesc(tupdesc);
+ return (Node *) fselect;
+ }
+ }
+
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_COLUMN),
+ errmsg("could not identify column \"%s\" in variable \"%s.%s\"",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ parser_errposition(pstate, location)));
+ }
+
+ return (Node *) param;
+}
+
static Node *
transformParamRef(ParseState *pstate, ParamRef *pref)
{
@@ -1815,6 +2028,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_VALUES:
case EXPR_KIND_VALUES_SINGLE:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
case EXPR_KIND_CHECK_CONSTRAINT:
@@ -1858,6 +2072,9 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_GENERATED_COLUMN:
err = _("cannot use subquery in column generation expression");
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ err = _("cannot use subquery as target of assign statement");
+ break;
/*
* There is intentionally no default: case here, so that the
@@ -3207,6 +3424,10 @@ ParseExprKindName(ParseExprKind exprKind)
return "GENERATED AS";
case EXPR_KIND_CYCLE_MARK:
return "CYCLE";
+ case EXPR_KIND_ASSIGN_TARGET:
+ return "ASSIGN";
+ case EXPR_KIND_LET_TARGET:
+ return "LET";
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index 583bbbf232f..dc25f6dcd0e 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2656,6 +2656,8 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location)
err = _("set-returning functions are not allowed in column generation expressions");
break;
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
errkind = true;
break;
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
index 51d7703eff7..244efcddf32 100644
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -405,6 +405,7 @@ transformMergeStmt(ParseState *pstate, MergeStmt *stmt)
qry->hasTargetSRFs = false;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c
index b44f9072280..446c71953bf 100644
--- a/src/backend/tcop/dest.c
+++ b/src/backend/tcop/dest.c
@@ -38,6 +38,7 @@
#include "executor/functions.h"
#include "executor/tqueue.h"
#include "executor/tstoreReceiver.h"
+#include "executor/svariableReceiver.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
@@ -155,6 +156,9 @@ CreateDestReceiver(CommandDest dest)
case DestExplainSerialize:
return CreateExplainSerializeDestReceiver(NULL);
+
+ case DestVariable:
+ return CreateVariableDestReceiver(InvalidOid);
}
/* should never get here */
@@ -191,6 +195,7 @@ EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_o
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -237,6 +242,7 @@ NullCommand(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -281,6 +287,7 @@ ReadyForQuery(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 99a51877d34..7a508a3644f 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -49,6 +49,7 @@
#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
+#include "commands/session_variable.h"
#include "commands/subscriptioncmds.h"
#include "commands/tablecmds.h"
#include "commands/tablespace.h"
@@ -235,6 +236,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CallStmt:
case T_DoStmt:
+ case T_LetStmt:
{
/*
* Commands inside the DO block or the called procedure might
@@ -1067,6 +1069,11 @@ standard_ProcessUtility(PlannedStmt *pstmt,
break;
}
+ case T_LetStmt:
+ ExecuteLetStmt(pstate, (LetStmt *) parsetree, params,
+ queryEnv, qc);
+ break;
+
default:
/* All other statement types have event trigger support */
ProcessUtilitySlow(pstate, pstmt, queryString,
@@ -2206,6 +2213,10 @@ UtilityContainsQuery(Node *parsetree)
return UtilityContainsQuery(qry->utilityStmt);
return qry;
+ case T_LetStmt:
+ qry = castNode(Query, ((LetStmt *) parsetree)->query);
+ return qry;
+
default:
return NULL;
}
@@ -2404,6 +2415,10 @@ CreateCommandTag(Node *parsetree)
tag = CMDTAG_SELECT;
break;
+ case T_LetStmt:
+ tag = CMDTAG_LET;
+ break;
+
/* utility statements --- same whether raw or cooked */
case T_TransactionStmt:
{
@@ -3289,6 +3304,7 @@ GetCommandLogLevel(Node *parsetree)
break;
case T_PLAssignStmt:
+ case T_LetStmt:
lev = LOGSTMT_ALL;
break;
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 54dad975553..7417054c38f 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -37,6 +37,7 @@
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablespace.h"
#include "common/keywords.h"
@@ -531,6 +532,7 @@ static char *generate_function_name(Oid funcid, int nargs,
static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2);
static void add_cast_to(StringInfo buf, Oid typid);
static char *generate_qualified_type_name(Oid typid);
+static char *generate_session_variable_name(Oid varid);
static text *string_to_text(char *str);
static char *flatten_reloptions(Oid relid);
static void get_reloptions(StringInfo buf, Datum reloptions);
@@ -8677,6 +8679,14 @@ get_parameter(Param *param, deparse_context *context)
return;
}
+ /* translate paramvarid to session variable name */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ return;
+ }
+
/*
* Alternatively, maybe it's a subplan output, which we print as a
* reference to the subplan. (We could drill down into the subplan and
@@ -13477,6 +13487,42 @@ generate_collation_name(Oid collid)
return result;
}
+/*
+ * generate_session_variable_name
+ * Compute the name to display for a session variable specified by OID
+ *
+ * The result includes all necessary quoting and schema-prefixing.
+ */
+static char *
+generate_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+ char *nspname;
+ char *result;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = NameStr(varform->varname);
+
+ if (!VariableIsVisible(varid))
+ nspname = get_namespace_name_or_temp(varform->varnamespace);
+ else
+ nspname = NULL;
+
+ result = quote_qualified_identifier(nspname, varname);
+
+ ReleaseSysCache(tup);
+
+ return result;
+}
+
/*
* Given a C string, produce a TEXT datum.
*
diff --git a/src/backend/utils/cache/plancache.c b/src/backend/utils/cache/plancache.c
index 55db8f53705..632c438a7bd 100644
--- a/src/backend/utils/cache/plancache.c
+++ b/src/backend/utils/cache/plancache.c
@@ -58,6 +58,7 @@
#include "access/transam.h"
#include "catalog/namespace.h"
+#include "catalog/pg_variable.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
@@ -162,6 +163,7 @@ InitPlanCache(void)
CacheRegisterSyscacheCallback(AMOPOPID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNSERVEROID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNDATAWRAPPEROID, PlanCacheSysCallback, (Datum) 0);
+ CacheRegisterSyscacheCallback(VARIABLEOID, PlanCacheObjectCallback, (Datum) 0);
}
/*
@@ -1903,17 +1905,32 @@ ScanQueryForLocks(Query *parsetree, bool acquire)
/*
* Recurse into sublink subqueries, too. But we already did the ones in
- * the rtable and cteList.
+ * the rtable and cteList. We need to force a recursive call for session
+ * variables too, to find and lock variables used in the query (see
+ * ScanQueryWalker).
*/
- if (parsetree->hasSubLinks)
+ if (parsetree->hasSubLinks ||
+ parsetree->hasSessionVariables)
{
query_tree_walker(parsetree, ScanQueryWalker, &acquire,
QTW_IGNORE_RC_SUBQUERIES);
}
+
+ /* process session variables */
+ if (OidIsValid(parsetree->resultVariable))
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ }
}
/*
- * Walker to find sublink subqueries for ScanQueryForLocks
+ * Walker to find sublink subqueries or referenced session variables
+ * for ScanQueryForLocks
*/
static bool
ScanQueryWalker(Node *node, bool *acquire)
@@ -1928,6 +1945,20 @@ ScanQueryWalker(Node *node, bool *acquire)
ScanQueryForLocks(castNode(Query, sub->subselect), *acquire);
/* Fall through to process lefthand args of SubLink */
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ }
+ }
/*
* Do NOT recurse into Query nodes, because ScanQueryForLocks already
@@ -2058,7 +2089,9 @@ PlanCacheRelCallback(Datum arg, Oid relid)
/*
* PlanCacheObjectCallback
- * Syscache inval callback function for PROCOID and TYPEOID caches
+ * Syscache inval callback function for TYPEOID, PROCOID, NAMESPACEOID,
+ * OPEROID, AMOPOPID, FOREIGNSERVEROID, FOREIGNDATAWRAPPEROID and
+ * VARIABLEOID caches.
*
* Invalidate all plans mentioning the object with the specified hash value,
* or all plans mentioning any member of this cache if hashvalue == 0.
diff --git a/src/backend/utils/fmgr/fmgr.c b/src/backend/utils/fmgr/fmgr.c
index aa89ae8fe1a..27691097890 100644
--- a/src/backend/utils/fmgr/fmgr.c
+++ b/src/backend/utils/fmgr/fmgr.c
@@ -2026,9 +2026,13 @@ get_call_expr_arg_stable(Node *expr, int argnum)
*/
if (IsA(arg, Const))
return true;
- if (IsA(arg, Param) &&
- ((Param *) arg)->paramkind == PARAM_EXTERN)
- return true;
+ if (IsA(arg, Param))
+ {
+ Param *p = (Param *) arg;
+
+ if (p->paramkind == PARAM_EXTERN || p->paramkind == PARAM_VARIABLE)
+ return true;
+ }
return false;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index c6a1bb09f3f..57364ea6a1c 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1214,8 +1214,8 @@ static const char *const sql_commands[] = {
"ABORT", "ALTER", "ANALYZE", "BEGIN", "CALL", "CHECKPOINT", "CLOSE", "CLUSTER",
"COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE",
"DELETE FROM", "DISCARD", "DO", "DROP", "END", "EXECUTE", "EXPLAIN",
- "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LISTEN", "LOAD", "LOCK",
- "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
+ "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LET",
+ "LISTEN", "LOAD", "LOCK", "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
"REASSIGN", "REFRESH MATERIALIZED VIEW", "REINDEX", "RELEASE",
"RESET", "REVOKE", "ROLLBACK",
"SAVEPOINT", "SECURITY LABEL", "SELECT", "SET", "SHOW", "START",
@@ -4664,6 +4664,14 @@ match_previous_words(int pattern_id,
else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES"))
COMPLETE_WITH("(");
+/* LET */
+ /* If prev. word is LET suggest a list of variables */
+ else if (Matches("LET"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ /* Complete LET <variable> with "=" */
+ else if (TailMatches("LET", MatchAny))
+ COMPLETE_WITH("=");
+
/* LOCK */
/* Complete LOCK [TABLE] [ONLY] with a list of tables */
else if (Matches("LOCK"))
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index bdac0c13bec..5060b8c9490 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -174,6 +174,7 @@ extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
extern List *NamesFromList(List *names);
extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+extern Oid IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror);
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 3d3c6eb24b5..5b45be5afaf 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -18,6 +18,7 @@
#ifndef PG_VARIABLE_H
#define PG_VARIABLE_H
+#include "access/xlogdefs.h"
#include "catalog/genbki.h"
#include "catalog/objectaddress.h"
#include "catalog/pg_variable_d.h"
@@ -35,6 +36,14 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* OID of entry in pg_type for variable's type */
Oid vartype BKI_LOOKUP(pg_type);
+ /*
+ * Used for identity check [oid, create_lsn].
+ *
+ * This column of the 8-byte XlogRecPtr type should be at an address that
+ * is divisible by 8, but before any column of type NameData.
+ */
+ XLogRecPtr varcreate_lsn;
+
/* variable name */
NameData varname;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
new file mode 100644
index 00000000000..2391b9ad443
--- /dev/null
+++ b/src/include/commands/session_variable.h
@@ -0,0 +1,30 @@
+/*-------------------------------------------------------------------------
+ *
+ * sessionvariable.h
+ * prototypes for sessionvariable.c.
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/commands/session_variable.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SESSIONVARIABLE_H
+#define SESSIONVARIABLE_H
+
+#include "nodes/params.h"
+#include "nodes/parsenodes.h"
+#include "parser/parse_node.h"
+#include "tcop/cmdtag.h"
+#include "utils/queryenvironment.h"
+
+extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
+extern Datum GetSessionVariable(Oid varid, bool *isNull);
+
+extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
+ QueryEnvironment *queryEnv, QueryCompletion *qc);
+
+#endif
diff --git a/src/include/executor/svariableReceiver.h b/src/include/executor/svariableReceiver.h
new file mode 100644
index 00000000000..db44d8b94c6
--- /dev/null
+++ b/src/include/executor/svariableReceiver.h
@@ -0,0 +1,22 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.h
+ * prototypes for svariableReceiver.c
+ *
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/executor/svariableReceiver.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SVARIABLE_RECEIVER_H
+#define SVARIABLE_RECEIVER_H
+
+#include "tcop/dest.h"
+
+extern DestReceiver *CreateVariableDestReceiver(Oid varid);
+
+#endif /* SVARIABLE_RECEIVER_H */
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index e2d1dc1e067..91051681d3b 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -635,6 +635,16 @@ typedef struct AsyncRequest
* tuples) */
} AsyncRequest;
+/* ----------------
+ * SessionVariableValue
+ * ----------------
+ */
+typedef struct SessionVariableValue
+{
+ bool isnull;
+ Datum value;
+} SessionVariableValue;
+
/* ----------------
* EState information
*
@@ -694,6 +704,10 @@ typedef struct EState
ParamListInfo es_param_list_info; /* values of external params */
ParamExecData *es_param_exec_vals; /* values of internal params */
+ /* Session variables info: */
+ int es_num_session_variables; /* number of used variables */
+ SessionVariableValue *es_session_variables; /* array of copies of values */
+
QueryEnvironment *es_queryEnv; /* query environment */
/* Other working state: */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index b07c42f94d0..b1e9efa6979 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -142,6 +142,9 @@ typedef struct Query
*/
int resultRelation pg_node_attr(query_jumble_ignore);
+ /* target variable of LET statement */
+ Oid resultVariable;
+
/* has aggregates in tlist or havingQual */
bool hasAggs pg_node_attr(query_jumble_ignore);
/* has window functions in tlist */
@@ -162,6 +165,8 @@ typedef struct Query
bool hasRowSecurity pg_node_attr(query_jumble_ignore);
/* parser has added an RTE_GROUP RTE */
bool hasGroupRTE pg_node_attr(query_jumble_ignore);
+ /* uses session variables */
+ bool hasSessionVariables pg_node_attr(query_jumble_ignore);
/* is a RETURN statement */
bool isReturn pg_node_attr(query_jumble_ignore);
@@ -2144,6 +2149,18 @@ typedef struct MergeStmt
ParseLoc stmt_len; /* length in bytes; 0 means "rest of string" */
} MergeStmt;
+/* ----------------------
+ * Let Statement
+ * ----------------------
+ */
+typedef struct LetStmt
+{
+ NodeTag type;
+ List *target; /* target variable */
+ Node *query; /* source expression */
+ ParseLoc location;
+} LetStmt;
+
/* ----------------------
* Select Statement
*
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index 00c700cc3e7..9667c1df416 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -179,6 +179,18 @@ typedef struct PlannerGlobal
/* partition descriptors */
PartitionDirectory partition_directory pg_node_attr(read_write_ignore);
+
+ /* list of used session variables */
+ List *sessionVariables;
+
+ /* Oid of session variable used like target of LET command */
+ Oid resultVariable;
+
+ /* oid of session variable used like base node for assignment indirection */
+ Oid basenodeSessionVarid;
+
+ /* true, if we do SELECT permission check on basenodeSessionVarid */
+ bool basenodeSessionVarSelectCheck;
} PlannerGlobal;
/* macro for fetching the Plan associated with a SubPlan node */
@@ -524,6 +536,8 @@ struct PlannerInfo
bool placeholdersFrozen;
/* true if planning a recursive WITH item */
bool hasRecursion;
+ /* true if session variables were used */
+ bool hasSessionVariables;
/*
* The rangetable index for the RTE_GROUP RTE, or 0 if there is no
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index bf1f25c0dba..1f739dc6140 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -128,6 +128,15 @@ typedef struct PlannedStmt
/* non-null if this is utility stmt */
Node *utilityStmt;
+ List *sessionVariables; /* OIDs for PARAM_VARIABLE Params */
+
+ /*
+ * The oid of session variable execluded from permission check.
+ * This session variable is used as base node of assignment indirection
+ * (and it is used only there).
+ */
+ int exclSelectPermCheckVarid;
+
/* statement location in source string (copied from Query) */
/* start location, or -1 if unknown */
ParseLoc stmt_location;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 839e71d52f4..2fa9b1bcd04 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -378,6 +378,9 @@ typedef struct Const
* of the `paramid' field contain the SubLink's subLinkId, and
* the low-order 16 bits contain the column number. (This type
* of Param is also converted to PARAM_EXEC during planning.)
+ *
+ * PARAM_VARIABLE: The parameter is a reference to a session variable
+ * (paramvarid holds the variable's OID).
*/
typedef enum ParamKind
{
@@ -385,6 +388,7 @@ typedef enum ParamKind
PARAM_EXEC,
PARAM_SUBLINK,
PARAM_MULTIEXPR,
+ PARAM_VARIABLE,
} ParamKind;
typedef struct Param
@@ -397,6 +401,16 @@ typedef struct Param
int32 paramtypmod pg_node_attr(query_jumble_ignore);
/* OID of collation, or InvalidOid if none */
Oid paramcollid pg_node_attr(query_jumble_ignore);
+ /* OID of session variable if it is used */
+ Oid paramvarid pg_node_attr(query_jumble_ignore);
+
+ /*
+ * true if param is used as base node of assignment indirection
+ * (when target of LET statement is an array field or an record field).
+ * For this param we do not check SELECT access right, because this
+ * param is used just for execution of UPDATE operation.
+ */
+ bool parambasenode;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index fee3378bbe3..e8551320d14 100644
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -125,4 +125,6 @@ extern void record_plan_function_dependency(PlannerInfo *root, Oid funcid);
extern void record_plan_type_dependency(PlannerInfo *root, Oid typid);
extern bool extract_query_dependencies_walker(Node *node, PlannerInfo *context);
+extern void pull_up_has_session_variables(PlannerInfo *root);
+
#endif /* PLANMAIN_H */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 793ace526df..431167f6b43 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -257,6 +257,7 @@ PG_KEYWORD("leading", LEADING, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("leakproof", LEAKPROOF, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("least", LEAST, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("left", LEFT, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("let", LET, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("level", LEVEL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("like", LIKE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("limit", LIMIT, RESERVED_KEYWORD, AS_LABEL)
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 994284019fb..0b7b69a4159 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -82,6 +82,8 @@ typedef enum ParseExprKind
EXPR_KIND_COPY_WHERE, /* WHERE condition in COPY FROM */
EXPR_KIND_GENERATED_COLUMN, /* generation expression for a column */
EXPR_KIND_CYCLE_MARK, /* cycle mark value */
+ EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */
+ EXPR_KIND_LET_TARGET, /* LET target */
} ParseExprKind;
@@ -244,6 +246,7 @@ struct ParseState
bool p_hasTargetSRFs;
bool p_hasSubLinks;
bool p_hasModifyingCTE;
+ bool p_hasSessionVariables;
Node *p_last_srf; /* most recent set-returning func/op found */
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index ea86954dded..22082c30008 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -186,6 +186,7 @@ PG_CMDTAG(CMDTAG_GRANT, "GRANT", true, false, false)
PG_CMDTAG(CMDTAG_GRANT_ROLE, "GRANT ROLE", false, false, false)
PG_CMDTAG(CMDTAG_IMPORT_FOREIGN_SCHEMA, "IMPORT FOREIGN SCHEMA", true, false, false)
PG_CMDTAG(CMDTAG_INSERT, "INSERT", false, false, true)
+PG_CMDTAG(CMDTAG_LET, "LET", false, false, false)
PG_CMDTAG(CMDTAG_LISTEN, "LISTEN", false, false, false)
PG_CMDTAG(CMDTAG_LOAD, "LOAD", false, false, false)
PG_CMDTAG(CMDTAG_LOCK_TABLE, "LOCK TABLE", false, false, false)
diff --git a/src/include/tcop/dest.h b/src/include/tcop/dest.h
index 00c092e3d7c..6ce3ea0e617 100644
--- a/src/include/tcop/dest.h
+++ b/src/include/tcop/dest.h
@@ -97,6 +97,7 @@ typedef enum
DestTransientRel, /* results sent to transient relation */
DestTupleQueue, /* results sent to tuple queue */
DestExplainSerialize, /* results are serialized and discarded */
+ DestVariable, /* results sent to session variable */
} CommandDest;
/* ----------------
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index d4377ceecbf..cb282404c1a 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8264,7 +8264,8 @@ exec_is_simple_query(PLpgSQL_expr *expr)
query->sortClause ||
query->limitOffset ||
query->limitCount ||
- query->setOperations)
+ query->setOperations ||
+ query->hasSessionVariables)
return false;
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index c36660ce6d3..f22467186e3 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -431,3 +431,1235 @@ DROP VARIABLE public.var1;
DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+-- check access rights
+CREATE ROLE regress_noowner;
+CREATE VARIABLE var1 AS int;
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+-- should fail
+SET ROLE TO regress_noowner;
+SELECT var1;
+ERROR: permission denied for session variable var1
+SELECT sqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: SQL function "sqlfx" statement 1
+SELECT plpgsqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "$1 + var1"
+PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
+-- should be ok
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+-- should be ok
+SET ROLE TO regress_noowner;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+DROP ROLE regress_noowner;
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- start a new session
+\c
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- should fail, dependency
+DROP VARIABLE var1;
+ERROR: cannot drop session variable var1 because other objects depend on it
+DETAIL: view test_view depends on session variable var1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+NOTICE: drop cascades to view test_view
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+LET var1 = 'str1';
+LET var2 = 'str2';
+SELECT sqlfx1(sqlfx2('Hello'));
+ sqlfx1
+-------------------
+ str1, str2, Hello
+(1 row)
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+ QUERY PLAN
+------------------------------------------------------
+ Result
+ Output: sqlfx1(sqlfx2('Hello'::character varying))
+(2 rows)
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+SET plan_cache_mode TO force_generic_plan;
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 3.14
+(1 row)
+
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 6.28
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 9.42
+(1 row)
+
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 12.56
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+ERROR: function plpgsqlfx2() does not exist
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+SET plan_cache_mode TO DEFAULT;
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 1
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 55
+DROP VARIABLE var1;
+DROP TABLE testvar;
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+NOTICE: result array: {1,2,3,4,5,6,7,8,9,10}
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+-- should not crash (but is not supported yet)
+CALL p(v);
+ERROR: session variable cannot be used as an argument
+DO $$ BEGIN CALL p(v); END $$;
+ERROR: session variable cannot be used as an argument
+CONTEXT: SQL statement "CALL p(v)"
+PL/pgSQL function inline_code_block line 1 at CALL
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+-- should fail
+EXECUTE ptest(v);
+ERROR: session variable cannot be used as an argument
+DEALLOCATE ptest;
+DROP VARIABLE v;
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+-- should fail
+LET var1 = pi();
+ERROR: session variable "var1" doesn't exist
+LINE 1: LET var1 = pi();
+ ^
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+ var1
+------------------
+ 3.14159265358979
+(1 row)
+
+SET search_path TO svartest;
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+ var1
+------------------
+ 13.1415926535898
+(1 row)
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to session variable svartest.var1
+CREATE VARIABLE var1 AS text;
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+SELECT var1;
+ var1
+-------
+ hello
+(1 row)
+
+DROP VARIABLE var1;
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+-- should fail
+SELECT var1;
+ERROR: domain int_domain does not allow null values
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+ var1
+------
+ 1000
+(1 row)
+
+-- should fail
+LET var1 = 10;
+ERROR: value for domain int_domain violates check constraint "int_domain_check"
+-- should fail
+LET var1 = NULL;
+ERROR: domain int_domain does not allow null values
+-- note - domain defaults are not supported yet (like PLpgSQL)
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+ var1
+----------------------------------------
+ {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+(1 row)
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+DROP VARIABLE var1;
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+ var1
+------
+ 100
+(1 row)
+
+SET search_path to public, svartest;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table foo
+drop cascades to session variable var1
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+LET var2[var1] = 0;
+SELECT var2;
+ var2
+-----------
+ [2:2]={0}
+(1 row)
+
+DROP VARIABLE var1, var2;
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+SELECT var2;
+ var2
+------
+ {}
+(1 row)
+
+DROP VARIABLE var1, var2;
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+ERROR: syntax error at or near "LET"
+LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x;
+ ^
+-- should be ok
+LET var1 = generate_series(1, 1);
+-- should fail
+LET var1 = generate_series(1, 2);
+ERROR: expression returned more than one row
+LET var1 = generate_series(1, 0);
+ERROR: expression returned no rows
+DROP VARIABLE var1;
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+SELECT v1;
+ v1
+------------
+ (1,2,3.00)
+(1 row)
+
+SELECT v2;
+ v2
+---------------
+ (10,20,31.40)
+(1 row)
+
+SELECT (v1).*;
+ x | y | z
+---+---+------
+ 1 | 2 | 3.00
+(1 row)
+
+SELECT (v2).*;
+ x | y | z
+----+----+-------
+ 10 | 20 | 31.40
+(1 row)
+
+SELECT v1.x + v1.z;
+ ?column?
+----------
+ 4.00
+(1 row)
+
+SELECT v2.x + v2.z;
+ ?column?
+----------
+ 41.40
+(1 row)
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail
+SELECT v2.x;
+ERROR: permission denied for session variable v2
+SET ROLE TO DEFAULT;
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+ERROR: improper qualified name (too many dotted names): nodb.noschema.novar.nofield.nosubfield
+LET nodb.noschema.novar.nofield = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar.nofield
+LET nodb.noschema.novar = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar
+CREATE TYPE t1 AS (a int, b numeric, c text);
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+ v1
+----------------------------
+ (1,3.14159265358979,hello)
+(1 row)
+
+LET v1.b = 10.2222;
+SELECT v1;
+ v1
+-------------------
+ (1,10.2222,hello)
+(1 row)
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1
+LINE 1: LET v1.x = 10;
+ ^
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+ERROR: assignment expression returned 3 columns
+LINE 1: LET v1 = (NULL::t1).*;
+ ^
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+ v1
+-------------
+ (1,10.2222)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+ v1
+--------------
+ (1,10.2222,)
+(1 row)
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+ v1
+--------------
+ (10,10.3,20)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+ v1
+---------
+ (10,20)
+(1 row)
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+ERROR: cannot alter type "t1" because session variable "public.v1" uses it
+DROP VARIABLE v1;
+DROP TYPE t1;
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+ var1
+----------------------------------
+ (10,3.14159265358979,05-26-2023)
+(1 row)
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+ERROR: cannot alter table "svar_test" because session variable "public.var1" uses it
+-- should fail
+DROP TABLE svar_test;
+ERROR: cannot drop table svar_test because other objects depend on it
+DETAIL: session variable var1 depends on type svar_test
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+CREATE ROLE regress_var_test_role;
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+-- should fail
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+SELECT var1.a;
+ a
+------
+ 1000
+(1 row)
+
+SELECT var1;
+ var1
+------------
+ (1000,100)
+(1 row)
+
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+NOTICE: (0,100)
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+NOTICE: 0
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail again
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+-- should fail
+SELECT var1.a;
+ERROR: variable "public.var1" is of type "text", which is not a composite type
+LINE 1: SELECT var1.a;
+ ^
+SELECT var2.c;
+ERROR: could not identify column "c" in variable "public.var2"
+LINE 1: SELECT var2.c;
+ ^
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+-- should fail
+LET var1 = '1'::jsonb;
+ERROR: variable "public.var1" is of type integer, but expression is of type jsonb
+LINE 1: LET var1 = '1'::jsonb;
+ ^
+HINT: You will need to rewrite or cast the expression.
+-- should be ok
+LET var1 = '1'::jsonb::int;
+-- should fail
+LET var1.x = 10;
+ERROR: cannot assign to field "x" of session variable "public.var1" because its type integer is not a composite type
+LINE 1: LET var1.x = 10;
+ ^
+DROP VARIABLE var1;
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+-- should fail
+LET vartest.vartest = 1;
+ERROR: target "vartest.vartest" of LET command is ambiguous
+LINE 1: LET vartest.vartest = 1;
+ ^
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+ERROR: type "vartesttype" does not exist
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+ var1
+------------
+ {10.1,2.1}
+(1 row)
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+ERROR: set-returning functions are not allowed in LET
+LINE 1: LET var1[generate_series(1,3)] = 100;
+ ^
+DROP VARIABLE var1;
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+ var1
+--------------------
+ (10.2,"{0.0,0.0}")
+(1 row)
+
+LET var1.b[1] = 10.3;
+SELECT var1;
+ var1
+---------------------
+ (10.2,"{10.3,0.0}")
+(1 row)
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ count
+-------
+ 100
+(1 row)
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ QUERY PLAN
+-----------------------------------
+ Aggregate
+ -> Seq Scan on svar_test
+ Filter: ((a % 10) = zero)
+(3 rows)
+
+LET zero = (SELECT count(*) FROM svar_test);
+-- result should be 1000
+SELECT zero;
+ zero
+------
+ 1000
+(1 row)
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO on;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO off;
+DROP VIEW var1view;
+DROP VARIABLE var1;
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 100
+(1 row)
+
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 200
+(1 row)
+
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+---
+(0 rows)
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+ relname
+----------
+ pg_class
+(1 row)
+
+DROP VARIABLE var1;
+CREATE TABLE xxtab(avar int);
+INSERT INTO xxtab VALUES(333);
+CREATE TYPE xxtype AS (avar int);
+CREATE VARIABLE xxtab AS xxtype;
+INSERT INTO xxtab VALUES(10);
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+CREATE VARIABLE public.avar AS int;
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+ avar
+------
+
+
+(2 rows)
+
+DROP VARIABLE xxtab;
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+DROP VARIABLE public.avar;
+DROP TYPE xxtype;
+DROP TABLE xxtab;
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+CREATE TABLE public.svar(a int, b int);
+INSERT INTO public.svar VALUES(10, 20);
+LET public.svar = (100, 200, 300);
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT var1.* FROM vartest_foo;
+ ^
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+ a | b
+----+----
+ 10 | 20
+ 30 | 40
+(2 rows)
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT count(var1.*) FROM vartest_foo;
+ ^
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+ count
+-------
+ 2
+(1 row)
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table vartest.vartest_foo
+drop cascades to session variable vartest.var1
+CREATE TYPE ab AS (a integer, b integer);
+CREATE VARIABLE v_ab AS ab;
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+CREATE SCHEMA v_ab;
+CREATE VARIABLE v_ab.a AS integer;
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+SET search_path TO public;
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+-- should be ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+-- should be still ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+ERROR: session variable reference "xxx_am.b" is ambiguous
+LINE 1: SELECT xxx_am.b;
+ ^
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+ b
+----
+ 10
+(1 row)
+
+SELECT :"DBNAME".xxx_am.b;
+ b
+----
+ 20
+(1 row)
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+ b
+----
+ 10
+(1 row)
+
+SELECT x.b FROM xxx_am x;
+ b
+----
+ 10
+(1 row)
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+CREATE SCHEMA :"DBNAME";
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+SET search_path TO :"DBNAME";
+-- should be ambiguous
+SELECT :"DBNAME".b;
+ERROR: session variable reference "regression.b" is ambiguous
+LINE 1: SELECT "regression".b;
+ ^
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+ERROR: session variable reference "regression.regression.b" is ambiguous
+LINE 1: SELECT "regression"."regression".b;
+ ^
+CREATE TABLE :"DBNAME"(b int);
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+ b
+---
+(0 rows)
+
+DROP TABLE :"DBNAME";
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+RESET search_path;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index eeb0f94ca3c..e72360d5254 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -295,3 +295,886 @@ DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+
+-- check access rights
+CREATE ROLE regress_noowner;
+
+CREATE VARIABLE var1 AS int;
+
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+SELECT sqlfx(20);
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx(20);
+SELECT plpgsqlfx_sd(20);
+
+-- should fail
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+-- should be ok
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx_sd(20);
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+
+-- should be ok
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+
+DROP ROLE regress_noowner;
+
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- start a new session
+\c
+
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- should fail, dependency
+DROP VARIABLE var1;
+
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+
+LET var1 = 'str1';
+LET var2 = 'str2';
+
+SELECT sqlfx1(sqlfx2('Hello'));
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+
+SET plan_cache_mode TO force_generic_plan;
+
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+
+SET plan_cache_mode TO DEFAULT;
+
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP TABLE testvar;
+
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+
+-- should not crash (but is not supported yet)
+CALL p(v);
+
+DO $$ BEGIN CALL p(v); END $$;
+
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+
+-- should fail
+EXECUTE ptest(v);
+
+DEALLOCATE ptest;
+DROP VARIABLE v;
+
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+
+-- should fail
+LET var1 = pi();
+SELECT var1;
+
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+
+SET search_path TO svartest;
+
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS text;
+
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+
+-- should fail
+SELECT var1;
+
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+
+-- should fail
+LET var1 = 10;
+
+-- should fail
+LET var1 = NULL;
+
+-- note - domain defaults are not supported yet (like PLpgSQL)
+
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+
+SET search_path to public, svartest;
+
+SELECT var1;
+
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+LET var2[var1] = 0;
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+
+-- should be ok
+LET var1 = generate_series(1, 1);
+
+-- should fail
+LET var1 = generate_series(1, 2);
+LET var1 = generate_series(1, 0);
+
+DROP VARIABLE var1;
+
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+
+SELECT v1;
+SELECT v2;
+SELECT (v1).*;
+SELECT (v2).*;
+
+SELECT v1.x + v1.z;
+SELECT v2.x + v2.z;
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should fail
+SELECT v2.x;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+LET nodb.noschema.novar.nofield = 10;
+LET nodb.noschema.novar = 10;
+
+CREATE TYPE t1 AS (a int, b numeric, c text);
+
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+LET v1.b = 10.2222;
+SELECT v1;
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+
+DROP VARIABLE v1;
+DROP TYPE t1;
+
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+
+-- should fail
+DROP TABLE svar_test;
+
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+
+CREATE ROLE regress_var_test_role;
+
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+
+-- should fail
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should fail again
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+
+-- should fail
+SELECT var1.a;
+SELECT var2.c;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+
+CREATE VARIABLE var1 AS int;
+
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+
+-- should fail
+LET var1 = '1'::jsonb;
+
+-- should be ok
+LET var1 = '1'::jsonb::int;
+
+-- should fail
+LET var1.x = 10;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+
+-- should fail
+LET vartest.vartest = 1;
+
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+
+DROP VARIABLE var1;
+
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+LET var1.b[1] = 10.3;
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+LET zero = (SELECT count(*) FROM svar_test);
+
+-- result should be 1000
+SELECT zero;
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO on;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO off;
+
+DROP VIEW var1view;
+DROP VARIABLE var1;
+
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+
+DROP VARIABLE var1;
+
+CREATE TABLE xxtab(avar int);
+
+INSERT INTO xxtab VALUES(333);
+
+CREATE TYPE xxtype AS (avar int);
+
+CREATE VARIABLE xxtab AS xxtype;
+
+INSERT INTO xxtab VALUES(10);
+
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+
+-- should be ok
+SELECT avar FROM xxtab;
+
+CREATE VARIABLE public.avar AS int;
+
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+
+DROP VARIABLE xxtab;
+
+SELECT xxtab.avar FROM xxtab;
+
+DROP VARIABLE public.avar;
+
+DROP TYPE xxtype;
+
+DROP TABLE xxtab;
+
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+
+CREATE TABLE public.svar(a int, b int);
+
+INSERT INTO public.svar VALUES(10, 20);
+
+LET public.svar = (100, 200, 300);
+
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+
+CREATE TYPE ab AS (a integer, b integer);
+
+CREATE VARIABLE v_ab AS ab;
+
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+CREATE SCHEMA v_ab;
+
+CREATE VARIABLE v_ab.a AS integer;
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+
+SET search_path TO public;
+
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+
+-- should be ok
+SELECT xxx_am;
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+
+-- should be still ok
+SELECT xxx_am;
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+SELECT :"DBNAME".xxx_am.b;
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+SELECT x.b FROM xxx_am x;
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+
+CREATE SCHEMA :"DBNAME";
+
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+
+SET search_path TO :"DBNAME";
+
+-- should be ambiguous
+SELECT :"DBNAME".b;
+
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+
+CREATE TABLE :"DBNAME"(b int);
+
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+
+DROP TABLE :"DBNAME";
+
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+
+RESET search_path;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b2844730f79..95c7a892f97 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1504,6 +1504,7 @@ LargeObjectDesc
Latch
LauncherLastStartTimesEntry
LerpFunc
+LetStmt
LexDescr
LexemeEntry
LexemeHashKey
@@ -2619,6 +2620,7 @@ SerializedTransactionState
Session
SessionBackupState
SessionEndType
+SessionVariableValue
SetConstraintState
SetConstraintStateData
SetConstraintTriggerData
@@ -2813,6 +2815,9 @@ SupportRequestRows
SupportRequestSelectivity
SupportRequestSimplify
SupportRequestWFuncMonotonic
+SVariable
+SVariableData
+SVariableState
Syn
SyncOps
SyncRepConfigData
--
2.48.1
[text/x-patch] v20250212-0001-Enhancing-catalog-for-support-session-variables-and-.patch (169.2K, ../../CAFj8pRBLparfcd2_hvAe0Evut-oO63UA2P6MrF3b+3NBLuMvwA@mail.gmail.com/24-v20250212-0001-Enhancing-catalog-for-support-session-variables-and-.patch)
download | inline diff:
From ac6f05ade72fc98ad553f60172a8fa62313b2f9e Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 15:41:55 +0100
Subject: [PATCH 01/22] Enhancing catalog for support session variables and
related support
This patch introduces new system catalog table pg_variable. This table holds metadata about
session variables created by command CREATE VARIABLE, and dropped by command DROP VARIABLE.
Both commands are implemented by this patch. Possibility to change owner, schema or rename.
Access to session variables can be controlled by SELECT or UPDATE rights. Both rights are
introduced by this patch too.
This patch enhancing pg_dump and psql to support session variables. The changes are related
to system catalog.
This patch is not short, but the code is simple.
---
doc/src/sgml/catalogs.sgml | 123 ++++-
doc/src/sgml/ddl.sgml | 40 +-
doc/src/sgml/func.sgml | 32 ++
doc/src/sgml/glossary.sgml | 15 +
doc/src/sgml/ref/allfiles.sgml | 3 +
.../sgml/ref/alter_default_privileges.sgml | 27 +-
doc/src/sgml/ref/alter_variable.sgml | 178 +++++++
doc/src/sgml/ref/comment.sgml | 1 +
doc/src/sgml/ref/create_schema.sgml | 12 +-
doc/src/sgml/ref/create_variable.sgml | 149 ++++++
doc/src/sgml/ref/drop_variable.sgml | 117 +++++
doc/src/sgml/ref/grant.sgml | 20 +-
doc/src/sgml/ref/psql-ref.sgml | 13 +
doc/src/sgml/ref/revoke.sgml | 8 +
doc/src/sgml/reference.sgml | 3 +
src/backend/catalog/Makefile | 1 +
src/backend/catalog/aclchk.c | 77 ++++
src/backend/catalog/dependency.c | 6 +
src/backend/catalog/meson.build | 1 +
src/backend/catalog/namespace.c | 221 +++++++++
src/backend/catalog/objectaddress.c | 121 ++++-
src/backend/catalog/pg_shdepend.c | 2 +
src/backend/catalog/pg_variable.c | 251 ++++++++++
src/backend/commands/alter.c | 9 +
src/backend/commands/dropcmds.c | 4 +
src/backend/commands/event_trigger.c | 4 +
src/backend/commands/seclabel.c | 1 +
src/backend/commands/tablecmds.c | 41 ++
src/backend/commands/typecmds.c | 15 +
src/backend/parser/gram.y | 105 ++++-
src/backend/parser/parse_utilcmd.c | 12 +
src/backend/tcop/utility.c | 20 +
src/backend/utils/adt/acl.c | 221 +++++++++
src/backend/utils/cache/lsyscache.c | 113 +++++
src/bin/pg_dump/common.c | 3 +
src/bin/pg_dump/dumputils.c | 6 +
src/bin/pg_dump/pg_backup.h | 2 +
src/bin/pg_dump/pg_backup_archiver.c | 9 +
src/bin/pg_dump/pg_dump.c | 190 ++++++++
src/bin/pg_dump/pg_dump.h | 15 +
src/bin/pg_dump/pg_dump_sort.c | 6 +
src/bin/pg_dump/t/002_pg_dump.pl | 64 +++
src/bin/psql/command.c | 3 +
src/bin/psql/describe.c | 100 +++-
src/bin/psql/describe.h | 3 +
src/bin/psql/help.c | 1 +
src/bin/psql/tab-complete.in.c | 43 +-
src/include/catalog/Makefile | 3 +-
src/include/catalog/meson.build | 1 +
src/include/catalog/namespace.h | 6 +
src/include/catalog/pg_default_acl.h | 1 +
src/include/catalog/pg_proc.dat | 23 +
src/include/catalog/pg_variable.h | 81 ++++
src/include/nodes/parsenodes.h | 16 +
src/include/parser/kwlist.h | 2 +
src/include/tcop/cmdtaglist.h | 3 +
src/include/utils/acl.h | 1 +
src/include/utils/lsyscache.h | 9 +
src/test/regress/expected/dependency.out | 17 +
src/test/regress/expected/oidjoins.out | 4 +
src/test/regress/expected/psql.out | 50 ++
.../regress/expected/session_variables.out | 433 ++++++++++++++++++
src/test/regress/parallel_schedule | 2 +-
src/test/regress/sql/dependency.sql | 14 +
src/test/regress/sql/psql.sql | 21 +
src/test/regress/sql/session_variables.sql | 297 ++++++++++++
src/tools/pgindent/typedefs.list | 4 +
67 files changed, 3363 insertions(+), 36 deletions(-)
create mode 100644 doc/src/sgml/ref/alter_variable.sgml
create mode 100644 doc/src/sgml/ref/create_variable.sgml
create mode 100644 doc/src/sgml/ref/drop_variable.sgml
create mode 100644 src/backend/catalog/pg_variable.c
create mode 100644 src/include/catalog/pg_variable.h
create mode 100644 src/test/regress/expected/session_variables.out
create mode 100644 src/test/regress/sql/session_variables.sql
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index ee59a7e15d0..7ba91b1f4b1 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -369,6 +369,11 @@
<entry><link linkend="catalog-pg-user-mapping"><structname>pg_user_mapping</structname></link></entry>
<entry>mappings of users to foreign servers</entry>
</row>
+
+ <row>
+ <entry><link linkend="catalog-pg-variable"><structname>pg_variable</structname></link></entry>
+ <entry>session variables</entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -3340,7 +3345,8 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
<literal>S</literal> = sequence,
<literal>f</literal> = function,
<literal>T</literal> = type,
- <literal>n</literal> = schema
+ <literal>n</literal> = schema,
+ <literal>V</literal> = session variable
</para></entry>
</row>
@@ -9758,4 +9764,119 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</table>
</sect1>
+ <sect1 id="catalog-pg-variable">
+ <title><structname>pg_variable</structname></title>
+
+ <indexterm zone="catalog-pg-variable">
+ <primary>pg_variable</primary>
+ </indexterm>
+
+ <para>
+ The catalog <structname>pg_variable</structname> stores information about
+ session variables.
+ </para>
+
+ <table>
+ <title><structname>pg_variable</structname> Columns</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ Column Type
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>oid</structfield> <type>oid</type>
+ </para>
+ <para>
+ Row identifier
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartype</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-type"><structname>pg_type</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the variable's data type
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varname</structfield> <type>name</type>
+ </para>
+ <para>
+ Name of the session variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varnamespace</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the namespace that contains this variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varowner</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ Owner of the variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartypmod</structfield> <type>int4</type>
+ </para>
+ <para>
+ <structfield>vartypmod</structfield> records type-specific data
+ supplied at variable creation time (for example, the maximum
+ length of a <type>varchar</type> column). It is passed to
+ type-specific input functions and length coercion functions.
+ The value will generally be -1 for types that do not need <structfield>vartypmod</structfield>.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcollation</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-collation"><structname>pg_collation</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The defined collation of the variable, or zero if the variable is
+ not of a collatable data type.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varacl</structfield> <type>aclitem[]</type>
+ </para>
+ <para>
+ Access privileges; see
+ <xref linkend="sql-grant"/> and
+ <xref linkend="sql-revoke"/>
+ for details
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+ </sect1>
</chapter>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index ae156b6b1cd..edfb7db24fc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -2020,6 +2020,7 @@ REVOKE ALL ON accounts FROM PUBLIC;
For sequences, this privilege also allows use of the
<function>currval</function> function.
For large objects, this privilege allows the object to be read.
+ For session variables, this privilege allows the object to be read.
</para>
</listitem>
</varlistentry>
@@ -2055,6 +2056,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<function>setval</function> functions.
For large objects, this privilege allows writing or truncating the
object.
+ For session variables, this privilege allows to set a value to the
+ object.
</para>
</listitem>
</varlistentry>
@@ -2298,7 +2301,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal> (and table-like objects),
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2313,7 +2317,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal>,
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2500,6 +2505,12 @@ REVOKE ALL ON accounts FROM PUBLIC;
<entry><literal>U</literal></entry>
<entry><literal>\dT+</literal></entry>
</row>
+ <row>
+ <entry><literal>SESSION VARIABLE</literal></entry>
+ <entry><literal>rw</literal></entry>
+ <entry><literal>none</literal></entry>
+ <entry><literal>\dV+</literal></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -5350,6 +5361,31 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
</para>
</sect1>
+ <sect1 id="ddl-session-variables">
+ <title>Session Variables</title>
+
+ <indexterm zone="ddl-session-variables">
+ <primary>Session variables</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ </indexterm>
+
+ <para>
+ Session variables are database objects that can hold a value.
+ Session variables, like relations, exist within a schema and their access
+ is controlled via <command>GRANT</command> and <command>REVOKE</command>
+ commands. A session variable can be created by the <command>CREATE
+ VARIABLE</command> command.
+ </para>
+
+ <para>
+ The session variable holds value in session memory. This value is private
+ to each session and is released when the session ends.
+ </para>
+ </sect1>
+
<sect1 id="ddl-others">
<title>Other Database Objects</title>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7efc81936ab..4a484034c0f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25337,6 +25337,25 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
</para></entry>
</row>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>has_session_variable_privilege</primary>
+ </indexterm>
+ <function>has_session_variable_privilege</function> (
+ <optional> <parameter>user</parameter> <type>name</type> or <type>oid</type>, </optional>
+ <parameter>session_variable</parameter> <type>text</type> or <type>oid</type>,
+ <parameter>privilege</parameter> <type>text</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Does user have privilege for session variable?
+ Allowable privilege types are
+ <literal>SELECT</literal>, and
+ <literal>UPDATE</literal>.
+ </para></entry>
+ </row>
+
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
@@ -25845,6 +25864,19 @@ SELECT relname FROM pg_class WHERE pg_table_is_visible(oid);
Is type (or domain) visible in search path?
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_variable_is_visible</primary>
+ </indexterm>
+ <function>pg_variable_is_visible</function> ( <parameter>variable</parameter> <type>oid</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Is session variable visible in search path?
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index c0f812e3f5e..b921f5a3339 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1669,6 +1669,21 @@
</glossdef>
</glossentry>
+ <glossentry id="glossary-session-variable">
+ <glossterm>Session variable</glossterm>
+ <glossdef>
+ <para>
+ A persistent database object that holds a value in session memory. This
+ value is private to each session and is released when the session ends.
+ Read or write access to session variables is controlled by privileges,
+ similar to other database objects.
+ </para>
+ <para>
+ For more information, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </glossdef>
+ </glossentry>
+
<glossentry id="glossary-shared-memory">
<glossterm>Shared memory</glossterm>
<glossdef>
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index f5be638867a..2f67de3e21b 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -47,6 +47,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY alterType SYSTEM "alter_type.sgml">
<!ENTITY alterUser SYSTEM "alter_user.sgml">
<!ENTITY alterUserMapping SYSTEM "alter_user_mapping.sgml">
+<!ENTITY alterVariable SYSTEM "alter_variable.sgml">
<!ENTITY alterView SYSTEM "alter_view.sgml">
<!ENTITY analyze SYSTEM "analyze.sgml">
<!ENTITY begin SYSTEM "begin.sgml">
@@ -99,6 +100,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY createType SYSTEM "create_type.sgml">
<!ENTITY createUser SYSTEM "create_user.sgml">
<!ENTITY createUserMapping SYSTEM "create_user_mapping.sgml">
+<!ENTITY createVariable SYSTEM "create_variable.sgml">
<!ENTITY createView SYSTEM "create_view.sgml">
<!ENTITY deallocate SYSTEM "deallocate.sgml">
<!ENTITY declare SYSTEM "declare.sgml">
@@ -147,6 +149,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY dropType SYSTEM "drop_type.sgml">
<!ENTITY dropUser SYSTEM "drop_user.sgml">
<!ENTITY dropUserMapping SYSTEM "drop_user_mapping.sgml">
+<!ENTITY dropVariable SYSTEM "drop_variable.sgml">
<!ENTITY dropView SYSTEM "drop_view.sgml">
<!ENTITY end SYSTEM "end.sgml">
<!ENTITY execute SYSTEM "execute.sgml">
diff --git a/doc/src/sgml/ref/alter_default_privileges.sgml b/doc/src/sgml/ref/alter_default_privileges.sgml
index 89aacec4fab..a5852d32566 100644
--- a/doc/src/sgml/ref/alter_default_privileges.sgml
+++ b/doc/src/sgml/ref/alter_default_privileges.sgml
@@ -51,6 +51,11 @@ GRANT { { USAGE | CREATE }
ON SCHEMAS
TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+GRANT { { SELECT | UPDATE }
+ [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+
REVOKE [ GRANT OPTION FOR ]
{ { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER | MAINTAIN }
[, ...] | ALL [ PRIVILEGES ] }
@@ -83,6 +88,12 @@ REVOKE [ GRANT OPTION FOR ]
ON SCHEMAS
FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
[ CASCADE | RESTRICT ]
+
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
+ [ CASCADE | RESTRICT ]
</synopsis>
</refsynopsisdiv>
@@ -117,14 +128,14 @@ REVOKE [ GRANT OPTION FOR ]
<para>
Currently,
only the privileges for schemas, tables (including views and foreign
- tables), sequences, functions, and types (including domains) can be
- altered. For this command, functions include aggregates and procedures.
- The words <literal>FUNCTIONS</literal> and <literal>ROUTINES</literal> are
- equivalent in this command. (<literal>ROUTINES</literal> is preferred
- going forward as the standard term for functions and procedures taken
- together. In earlier PostgreSQL releases, only the
- word <literal>FUNCTIONS</literal> was allowed. It is not possible to set
- default privileges for functions and procedures separately.)
+ tables), sequences, functions, types (including domains), and session
+ variables can be altered. For this command, functions include aggregates
+ and procedures. The words <literal>FUNCTIONS</literal> and
+ <literal>ROUTINES</literal> are equivalent in this command.
+ (<literal>ROUTINES</literal> is preferred going forward as the standard
+ term for functions and procedures taken together. In earlier PostgreSQL
+ releases, only the word <literal>FUNCTIONS</literal> was allowed. It is not
+ possible to set default privileges for functions and procedures separately.)
</para>
<para>
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
new file mode 100644
index 00000000000..96d2586423e
--- /dev/null
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -0,0 +1,178 @@
+<!--
+doc/src/sgml/ref/alter_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-altervariable">
+ <indexterm zone="sql-altervariable">
+ <primary>ALTER VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>altering</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>ALTER VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>ALTER VARIABLE</refname>
+ <refpurpose>
+ change the definition of a session variable
+ </refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable class="parameter">new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable class="parameter">new_name</replaceable>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> SET SCHEMA <replaceable class="parameter">new_schema</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>ALTER VARIABLE</command> command changes the definition of an
+ existing session variable. There are several subforms:
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>OWNER</literal></term>
+ <listitem>
+ <para>
+ This form changes the owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RENAME</literal></term>
+ <listitem>
+ <para>
+ This form changes the name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>SET SCHEMA</literal></term>
+ <listitem>
+ <para>
+ This form moves the session variable into another schema.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </para>
+
+ <para>
+ Only the owner or a superuser is allowed to alter a session variable.
+ In order to move a session variable from one schema to another, the user
+ must also have the <literal>CREATE</literal> privilege on the new schema (or
+ be a superuser).
+
+ In order to move the session variable ownership from one role to another,
+ the user must also be a direct or indirect member of the new
+ owning role, and that role must have the <literal>CREATE</literal> privilege
+ on the session variable's schema (or be a superuser). These restrictions
+ enforce that altering the owner doesn't do anything you couldn't do by
+ dropping and recreating the session variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <para>
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name (possibly schema-qualified) of the existing session variable
+ to alter.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_owner</replaceable></term>
+ <listitem>
+ <para>
+ The user name of the new owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_name</replaceable></term>
+ <listitem>
+ <para>
+ The new name for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_schema</replaceable></term>
+ <listitem>
+ <para>
+ The new schema for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To rename a session variable:
+<programlisting>
+ALTER VARIABLE foo RENAME TO boo;
+</programlisting>
+ </para>
+
+ <para>
+ To change the owner of the session variable <literal>boo</literal> to
+ <literal>joe</literal>:
+<programlisting>
+ALTER VARIABLE boo OWNER TO joe;
+</programlisting>
+ </para>
+
+ <para>
+ To change the schema of the session variable <literal>boo</literal> to
+ <literal>private</literal>:
+<programlisting>
+ALTER VARIABLE boo SET SCHEMA private;
+</programlisting>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ Session variables and this command in particular are a PostgreSQL extension.
+ </para>
+ </refsect1>
+
+ <refsect1 id="sql-altervariable-see-also">
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index 5b43c56b133..21cd80818fb 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -65,6 +65,7 @@ COMMENT ON
TRANSFORM FOR <replaceable>type_name</replaceable> LANGUAGE <replaceable>lang_name</replaceable> |
TRIGGER <replaceable class="parameter">trigger_name</replaceable> ON <replaceable class="parameter">table_name</replaceable> |
TYPE <replaceable class="parameter">object_name</replaceable> |
+ VARIABLE <replaceable class="parameter">object_name</replaceable> |
VIEW <replaceable class="parameter">object_name</replaceable>
} IS { <replaceable class="parameter">string_literal</replaceable> | NULL }
diff --git a/doc/src/sgml/ref/create_schema.sgml b/doc/src/sgml/ref/create_schema.sgml
index ed69298ccc6..d2bb265209b 100644
--- a/doc/src/sgml/ref/create_schema.sgml
+++ b/doc/src/sgml/ref/create_schema.sgml
@@ -103,9 +103,10 @@ CREATE SCHEMA IF NOT EXISTS AUTHORIZATION <replaceable class="parameter">role_sp
schema. Currently, only <command>CREATE
TABLE</command>, <command>CREATE VIEW</command>, <command>CREATE
INDEX</command>, <command>CREATE SEQUENCE</command>, <command>CREATE
- TRIGGER</command> and <command>GRANT</command> are accepted as clauses
- within <command>CREATE SCHEMA</command>. Other kinds of objects may
- be created in separate commands after the schema is created.
+ TRIGGER</command>, <command>GRANT</command> and <command>CREATE
+ VARIABLE</command> are accepted as clauses within <command>CREATE
+ SCHEMA</command>. Other kinds of objects may be created in separate
+ commands after the schema is created.
</para>
</listitem>
</varlistentry>
@@ -214,6 +215,11 @@ CREATE VIEW hollywood.winners AS
The <literal>IF NOT EXISTS</literal> option is a
<productname>PostgreSQL</productname> extension.
</para>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
</refsect1>
<refsect1>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
new file mode 100644
index 00000000000..6e988f2e472
--- /dev/null
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -0,0 +1,149 @@
+<!--
+doc/src/sgml/ref/create_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-createvariable">
+ <indexterm zone="sql-createvariable">
+ <primary>CREATE VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>defining</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>CREATE VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>CREATE VARIABLE</refname>
+ <refpurpose>define a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+</synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command creates a session variable.
+ Session variables, like relations, exist within a schema and their access is
+ controlled via the commands <command>GRANT</command> and <command>REVOKE</command>.
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a session variable's value returns NULL, unless its value is set to
+ something else in the current session with a <command>LET</command> command.
+ The content of a session variable is not transactional. This is the same as
+ regular variables in procedural languages.
+ </para>
+
+ <para>
+ Session variables are retrieved by the <command>SELECT</command>
+ command. Their value is set with the <command>LET</command> command.
+ </para>
+
+ <note>
+ <para>
+ Session variables can be <quote>shadowed</quote> by other identifiers.
+ For details, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </note>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+
+ <varlistentry id="sql-createvariable-if-not-exists">
+ <term><literal>IF NOT EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the name already exists. A notice is issued in
+ this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-name">
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-data_type">
+ <term><replaceable class="parameter">data_type</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the data type of the session
+ variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-collate">
+ <term><literal>COLLATE <replaceable>collation</replaceable></literal></term>
+ <listitem>
+ <para>
+ The <literal>COLLATE</literal> clause assigns a collation to the session
+ variable (which must be of a collatable data type). If not specified,
+ the data type's default collation is used.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para>
+ Use the <command>DROP VARIABLE</command> command to remove a session
+ variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ Create an date session variable <literal>var1</literal>:
+<programlisting>
+CREATE VARIABLE var1 AS date;
+</programlisting>
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
new file mode 100644
index 00000000000..5bdb3560f0b
--- /dev/null
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -0,0 +1,117 @@
+<!--
+doc/src/sgml/ref/drop_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-dropvariable">
+ <indexterm zone="sql-dropvariable">
+ <primary>DROP VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>removing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>DROP VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>DROP VARIABLE</refname>
+ <refpurpose>remove a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+DROP VARIABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ <command>DROP VARIABLE</command> removes a session variable.
+ A session variable can only be removed by its owner or a superuser.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>IF EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the session variable does not exist. A notice is
+ issued in this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of a session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>CASCADE</literal></term>
+ <listitem>
+ <para>
+ Automatically drop objects that depend on the session variable (such as
+ views), and in turn all objects that depend on those objects
+ (see <xref linkend="ddl-depend"/>).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RESTRICT</literal></term>
+ <listitem>
+ <para>
+ Refuse to drop the session variable if any objects depend on it. This is
+ the default.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To remove the session variable <literal>var1</literal>:
+
+<programlisting>
+DROP VARIABLE var1;
+</programlisting></para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>DROP VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index 999f657d5c0..c11860fa200 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -101,6 +101,12 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
[ WITH { ADMIN | INHERIT | SET } { OPTION | TRUE | FALSE } ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+GRANT { SELECT | UPDATE | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
@@ -119,8 +125,8 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
that grants privileges on a database object (table, column, view,
foreign table, sequence, database, foreign-data wrapper, foreign server,
function, procedure, procedural language, large object, configuration
- parameter, schema, tablespace, or type), and one that grants
- membership in a role. These variants are similar in many ways, but
+ parameter, schema, session variable, tablespace, or type), and one that
+ grants membership in a role. These variants are similar in many ways, but
they are different enough to be described separately.
</para>
@@ -236,9 +242,9 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
<para>
There is also an option to grant privileges on all objects of the same
type within one or more schemas. This functionality is currently supported
- only for tables, sequences, functions, and procedures. <literal>ALL
- TABLES</literal> also affects views and foreign tables, just like the
- specific-object <command>GRANT</command> command. <literal>ALL
+ only for tables, sequences, functions, procedures and variables.
+ <literal>ALL TABLES</literal> also affects views and foreign tables, just
+ like the specific-object <command>GRANT</command> command. <literal>ALL
FUNCTIONS</literal> also affects aggregate and window functions, but not
procedures, again just like the specific-object <command>GRANT</command>
command. Use <literal>ALL ROUTINES</literal> to include procedures.
@@ -518,8 +524,8 @@ GRANT admins TO joe;
</para>
<para>
- Privileges on databases, tablespaces, schemas, languages, and
- configuration parameters are
+ Privileges on databases, tablespaces, schemas, languages, session variables
+ and configuration parameters are
<productname>PostgreSQL</productname> extensions.
</para>
</refsect1>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index f3044fac1fa..da9ef01ddea 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -2134,6 +2134,19 @@ SELECT $1 \parse stmt1
</listitem>
</varlistentry>
+ <varlistentry id="app-psql-meta-command-dv">
+ <term><literal>\dV[+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
+ <listitem>
+ <para>
+ Lists session variables.
+ If <replaceable class="parameter">pattern</replaceable> is
+ specified, only session variables whose names match the pattern are listed.
+ If the form <literal>\dV+</literal> is used, additional information
+ about each variable is shown, like access privileges and description.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="app-psql-meta-command-du">
<term><literal>\du[Sx+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
<listitem>
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index 8df492281a1..760fddb7c20 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -130,6 +130,14 @@ REVOKE [ { ADMIN | INHERIT | SET } OPTION FOR ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
[ CASCADE | RESTRICT ]
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ FROM { <replaceable class="parameter">role_specification</replaceable> | PUBLIC } [, ...]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+ [ CASCADE | RESTRICT ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index ff85ace83fc..25578f3946c 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -75,6 +75,7 @@
&alterType;
&alterUser;
&alterUserMapping;
+ &alterVariable;
&alterView;
&analyze;
&begin;
@@ -127,6 +128,7 @@
&createType;
&createUser;
&createUserMapping;
+ &createVariable;
&createView;
&deallocate;
&declare;
@@ -175,6 +177,7 @@
&dropType;
&dropUser;
&dropUserMapping;
+ &dropVariable;
&dropView;
&end;
&execute;
diff --git a/src/backend/catalog/Makefile b/src/backend/catalog/Makefile
index c090094ed08..2c20d60db19 100644
--- a/src/backend/catalog/Makefile
+++ b/src/backend/catalog/Makefile
@@ -45,6 +45,7 @@ OBJS = \
pg_shdepend.o \
pg_subscription.o \
pg_type.o \
+ pg_variable.o \
storage.o \
toasting.o
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 02a754cc30a..1e8ce752b90 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -64,6 +64,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -291,6 +292,9 @@ restrict_and_check_grant(bool is_grant, AclMode avail_goptions, bool all_privs,
case OBJECT_PARAMETER_ACL:
whole_mask = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ whole_mask = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", objtype);
/* not reached, but keep compiler quiet */
@@ -535,6 +539,10 @@ ExecuteGrantStmt(GrantStmt *stmt)
all_privileges = ACL_ALL_RIGHTS_PARAMETER_ACL;
errormsg = gettext_noop("invalid privilege type %s for parameter");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) stmt->objtype);
@@ -640,6 +648,9 @@ ExecGrantStmt_oids(InternalGrant *istmt)
case OBJECT_PARAMETER_ACL:
ExecGrant_Parameter(istmt);
break;
+ case OBJECT_VARIABLE:
+ ExecGrant_common(istmt, VariableRelationId, ACL_ALL_RIGHTS_VARIABLE, NULL);
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) istmt->objtype);
@@ -760,6 +771,18 @@ objectNamesToOids(ObjectType objtype, List *objnames, bool is_grant)
objects = lappend_oid(objects, parameterId);
}
break;
+
+ case OBJECT_VARIABLE:
+ foreach_node(RangeVar, varvar, objnames)
+ {
+ Oid relOid;
+
+ relOid = LookupVariable(varvar->schemaname,
+ varvar->relname,
+ false);
+ objects = lappend_oid(objects, relOid);
+ }
+ break;
}
return objects;
@@ -846,6 +869,32 @@ objectsInSchemaToOids(ObjectType objtype, List *nspnames)
table_close(rel, AccessShareLock);
}
break;
+ case OBJECT_VARIABLE:
+ {
+ ScanKeyData key;
+ Relation rel;
+ TableScanDesc scan;
+ HeapTuple tuple;
+
+ ScanKeyInit(&key,
+ Anum_pg_variable_varnamespace,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(namespaceId));
+
+ rel = table_open(VariableRelationId, AccessShareLock);
+ scan = table_beginscan_catalog(rel, 1, &key);
+
+ while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+ {
+ Oid oid = ((Form_pg_proc) GETSTRUCT(tuple))->oid;
+
+ objects = lappend_oid(objects, oid);
+ }
+
+ table_endscan(scan);
+ table_close(rel, AccessShareLock);
+ }
+ break;
default:
/* should not happen */
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
@@ -1005,6 +1054,10 @@ ExecAlterDefaultPrivilegesStmt(ParseState *pstate, AlterDefaultPrivilegesStmt *s
all_privileges = ACL_ALL_RIGHTS_SCHEMA;
errormsg = gettext_noop("invalid privilege type %s for schema");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) action->objtype);
@@ -1196,6 +1249,12 @@ SetDefaultACL(InternalDefaultACL *iacls)
this_privileges = ACL_ALL_RIGHTS_SCHEMA;
break;
+ case OBJECT_VARIABLE:
+ objtype = DEFACLOBJ_VARIABLE;
+ if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
+ this_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ break;
+
default:
elog(ERROR, "unrecognized object type: %d",
(int) iacls->objtype);
@@ -1439,6 +1498,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case DEFACLOBJ_NAMESPACE:
iacls.objtype = OBJECT_SCHEMA;
break;
+ case DEFACLOBJ_VARIABLE:
+ iacls.objtype = OBJECT_VARIABLE;
+ break;
default:
/* Shouldn't get here */
elog(ERROR, "unexpected default ACL type: %d",
@@ -1499,6 +1561,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case ParameterAclRelationId:
istmt.objtype = OBJECT_PARAMETER_ACL;
break;
+ case VariableRelationId:
+ istmt.objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unexpected object class %u", classid);
break;
@@ -2732,6 +2797,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("permission denied for type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("permission denied for session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("permission denied for view %s");
break;
@@ -2843,6 +2911,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("must be owner of type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("must be owner of session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("must be owner of view %s");
break;
@@ -2991,6 +3062,8 @@ pg_aclmask(ObjectType objtype, Oid object_oid, AttrNumber attnum, Oid roleid,
return ACL_NO_RIGHTS;
case OBJECT_TYPE:
return object_aclmask(TypeRelationId, object_oid, roleid, mask, how);
+ case OBJECT_VARIABLE:
+ return object_aclmask(VariableRelationId, object_oid, roleid, mask, how);
default:
elog(ERROR, "unrecognized object type: %d",
(int) objtype);
@@ -4250,6 +4323,10 @@ get_user_default_acl(ObjectType objtype, Oid ownerId, Oid nsp_oid)
defaclobjtype = DEFACLOBJ_NAMESPACE;
break;
+ case OBJECT_VARIABLE:
+ defaclobjtype = DEFACLOBJ_VARIABLE;
+ break;
+
default:
return NULL;
}
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 18316a3968b..9e0f648b74f 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -65,12 +65,14 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/comment.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "commands/extension.h"
#include "commands/policy.h"
#include "commands/publicationcmds.h"
+#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
#include "commands/trigger.h"
@@ -1444,6 +1446,10 @@ doDeletion(const ObjectAddress *object, int flags)
RemovePublicationById(object->objectId);
break;
+ case VariableRelationId:
+ DropVariableById(object->objectId);
+ break;
+
case CastRelationId:
case CollationRelationId:
case ConversionRelationId:
diff --git a/src/backend/catalog/meson.build b/src/backend/catalog/meson.build
index 1958ea9238a..ed44c877fca 100644
--- a/src/backend/catalog/meson.build
+++ b/src/backend/catalog/meson.build
@@ -32,6 +32,7 @@ backend_sources += files(
'pg_shdepend.c',
'pg_subscription.c',
'pg_type.c',
+ 'pg_variable.c',
'storage.c',
'toasting.c',
)
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index d97d632a7ef..4307cad15c7 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "common/hashfn_unstable.h"
#include "funcapi.h"
@@ -225,6 +226,7 @@ static bool TSParserIsVisibleExt(Oid prsId, bool *is_missing);
static bool TSDictionaryIsVisibleExt(Oid dictId, bool *is_missing);
static bool TSTemplateIsVisibleExt(Oid tmplId, bool *is_missing);
static bool TSConfigIsVisibleExt(Oid cfgid, bool *is_missing);
+static bool VariableIsVisibleExt(Oid varid, bool *is_missing);
static void recomputeNamespacePath(void);
static void AccessTempTableNamespace(bool force);
static void InitTempTableNamespace(void);
@@ -986,6 +988,84 @@ RelationIsVisibleExt(Oid relid, bool *is_missing)
return visible;
}
+/*
+ * VariableIsVisible
+ * Determine whether a variable (identified by OID) is visible in the
+ * current search path. Visible means "would be found by searching
+ * for the unqualified variable name".
+ */
+bool
+VariableIsVisible(Oid varid)
+{
+ return VariableIsVisibleExt(varid, NULL);
+}
+
+/*
+ * VariableIsVisibleExt
+ * As above, but if the variable isn't found and is_missing is not NULL,
+ * then set *is_missing = true and return false, instead of throwing
+ * an error. (Caller must initialize *is_missing = false.)
+ */
+static bool
+VariableIsVisibleExt(Oid varid, bool *is_missing)
+{
+ HeapTuple vartup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+ bool visible;
+
+ vartup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+ if (!HeapTupleIsValid(vartup))
+ {
+ if (is_missing != NULL)
+ {
+ *is_missing = true;
+ return false;
+ }
+
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+ }
+ varform = (Form_pg_variable) GETSTRUCT(vartup);
+
+ recomputeNamespacePath();
+
+ /*
+ * Quick check: if it ain't in the path at all, it ain't visible. We
+ * don't expect usage of session variables in the system namespace.
+ */
+ varnamespace = varform->varnamespace;
+ if (!list_member_oid(activeSearchPath, varnamespace))
+ visible = false;
+ else
+ {
+ /*
+ * If it is in the path, it might still not be visible; it could be
+ * hidden by another variable of the same name earlier in the path. So
+ * we must do a slow check for conflicting relations.
+ */
+ char *varname = NameStr(varform->varname);
+
+ visible = false;
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ if (namespaceId == varnamespace)
+ {
+ /* found it first in path */
+ visible = true;
+ break;
+ }
+ if (OidIsValid(get_varname_varid(varname, namespaceId)))
+ {
+ /* found something else first in path */
+ break;
+ }
+ }
+ }
+
+ ReleaseSysCache(vartup);
+
+ return visible;
+}
/*
* TypenameGetTypid
@@ -3289,6 +3369,133 @@ TSConfigIsVisibleExt(Oid cfgid, bool *is_missing)
return visible;
}
+/*
+ * Returns oid of session variable specified by possibly qualified identifier.
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariable(const char *nspname,
+ const char *varname,
+ bool missing_ok)
+{
+ Oid varoid = InvalidOid;
+
+ if (nspname)
+ {
+ Oid namespaceId = LookupExplicitNamespace(nspname, missing_ok);
+
+ /* if nspname is a known namespace, the variable must be there */
+ if (OidIsValid(namespaceId))
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+ }
+ }
+ else
+ {
+ /* iterate over the schemas on the search_path */
+ recomputeNamespacePath();
+
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+
+ if (OidIsValid(varoid))
+ break;
+ }
+ }
+
+ if (!OidIsValid(varoid) && !missing_ok)
+ {
+ if (nspname)
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s.%s\" does not exist",
+ nspname, varname)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" does not exist",
+ varname)));
+ }
+
+ return varoid;
+}
+
+/*
+ * Returns oid of session variable specified by possibly qualified identifier
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariableFromNameList(List *names,
+ bool missing_ok)
+{
+ char *catname = NULL;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ switch (list_length(names))
+ {
+ case 1:
+ varname = strVal(linitial(names));
+ break;
+ case 2:
+ nspname = strVal(linitial(names));
+ varname = strVal(lsecond(names));
+ break;
+ case 3:
+ catname = strVal(linitial(names));
+ nspname = strVal(lsecond(names));
+ varname = strVal(lthird(names));
+
+ /* check catalog name */
+ if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ break;
+ default:
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper session variable name (too many dotted names): %s",
+ NameListToString(names))));
+ break;
+ }
+
+ return LookupVariable(nspname, varname, missing_ok);
+}
+
+/*
+ * The input list contains names with indirection expressions used as the left
+ * part of LET statement. The following routine returns a new list with only
+ * initial strings (names) - without indirection expressions.
+ */
+List *
+NamesFromList(List *names)
+{
+ ListCell *l;
+ List *result = NIL;
+
+ foreach(l, names)
+ {
+ Node *n = lfirst(l);
+
+ if (IsA(n, String))
+ {
+ result = lappend(result, n);
+ }
+ else
+ break;
+ }
+
+ return result;
+}
/*
* DeconstructQualifiedName
@@ -5085,3 +5292,17 @@ pg_is_other_temp_schema(PG_FUNCTION_ARGS)
PG_RETURN_BOOL(isOtherTempNamespace(oid));
}
+
+Datum
+pg_variable_is_visible(PG_FUNCTION_ARGS)
+{
+ Oid oid = PG_GETARG_OID(0);
+ bool result;
+ bool is_missing = false;
+
+ result = VariableIsVisibleExt(oid, &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+ PG_RETURN_BOOL(result);
+}
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index d8eb8d3deaa..4a464dfea7e 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -62,6 +62,7 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -636,6 +637,20 @@ static const ObjectPropertyType ObjectProperty[] =
OBJECT_USER_MAPPING,
false
},
+ {
+ "session variable",
+ VariableRelationId,
+ VariableOidIndexId,
+ VARIABLEOID,
+ VARIABLENAMENSP,
+ Anum_pg_variable_oid,
+ Anum_pg_variable_varname,
+ Anum_pg_variable_varnamespace,
+ Anum_pg_variable_varowner,
+ Anum_pg_variable_varacl,
+ OBJECT_VARIABLE,
+ true
+ }
};
/*
@@ -831,6 +846,9 @@ static const struct object_type_map
},
{
"statistics object", OBJECT_STATISTIC_EXT
+ },
+ {
+ "session variable", OBJECT_VARIABLE
}
};
@@ -856,6 +874,7 @@ static ObjectAddress get_object_address_attrdef(ObjectType objtype,
bool missing_ok);
static ObjectAddress get_object_address_type(ObjectType objtype,
TypeName *typename, bool missing_ok);
+static ObjectAddress get_object_address_variable(List *object, bool missing_ok);
static ObjectAddress get_object_address_opcf(ObjectType objtype, List *object,
bool missing_ok);
static ObjectAddress get_object_address_opf_member(ObjectType objtype,
@@ -1127,6 +1146,9 @@ get_object_address(ObjectType objtype, Node *object,
missing_ok);
address.objectSubId = 0;
break;
+ case OBJECT_VARIABLE:
+ address = get_object_address_variable(castNode(List, object), missing_ok);
+ break;
/* no default, to let compiler warn about missing case */
}
@@ -2005,16 +2027,20 @@ get_object_address_defacl(List *object, bool missing_ok)
case DEFACLOBJ_NAMESPACE:
objtype_str = "schemas";
break;
+ case DEFACLOBJ_VARIABLE:
+ objtype_str = "variables";
+ break;
default:
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized default ACL object type \"%c\"", objtype),
- errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
+ errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
DEFACLOBJ_RELATION,
DEFACLOBJ_SEQUENCE,
DEFACLOBJ_FUNCTION,
DEFACLOBJ_TYPE,
- DEFACLOBJ_NAMESPACE)));
+ DEFACLOBJ_NAMESPACE,
+ DEFACLOBJ_VARIABLE)));
}
/*
@@ -2098,6 +2124,24 @@ textarray_to_strvaluelist(ArrayType *arr)
return list;
}
+/*
+ * Find the ObjectAddress for a session variable
+ */
+static ObjectAddress
+get_object_address_variable(List *object, bool missing_ok)
+{
+ ObjectAddress address;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ ObjectAddressSet(address, VariableRelationId, InvalidOid);
+
+ DeconstructQualifiedName(object, &nspname, &varname);
+ address.objectId = LookupVariable(nspname, varname, missing_ok);
+
+ return address;
+}
+
/*
* SQL-callable version of get_object_address
*/
@@ -2292,6 +2336,7 @@ pg_get_object_address(PG_FUNCTION_ARGS)
case OBJECT_TABCONSTRAINT:
case OBJECT_OPCLASS:
case OBJECT_OPFAMILY:
+ case OBJECT_VARIABLE:
objnode = (Node *) name;
break;
case OBJECT_ACCESS_METHOD:
@@ -2463,6 +2508,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
case OBJECT_STATISTIC_EXT:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
if (!object_ownercheck(address.classId, address.objectId, roleid))
aclcheck_error(ACLCHECK_NOT_OWNER, objtype,
NameListToString(castNode(List, object)));
@@ -3492,6 +3538,32 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
break;
}
+ case VariableRelationId:
+ {
+ char *nspname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ if (VariableIsVisible(object->objectId))
+ nspname = NULL;
+ else
+ nspname = get_namespace_name(varform->varnamespace);
+
+ appendStringInfo(&buffer, _("session variable %s"),
+ quote_qualified_identifier(nspname,
+ NameStr(varform->varname)));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
case TSParserRelationId:
{
HeapTuple tup;
@@ -3844,6 +3916,16 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
_("default privileges on new schemas belonging to role %s"),
rolename);
break;
+ case DEFACLOBJ_VARIABLE:
+ if (nspname)
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s in schema %s"),
+ rolename, nspname);
+ else
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s"),
+ rolename);
+ break;
default:
/* shouldn't get here */
if (nspname)
@@ -4660,6 +4742,10 @@ getObjectTypeDescription(const ObjectAddress *object, bool missing_ok)
appendStringInfoString(&buffer, "transform");
break;
+ case VariableRelationId:
+ appendStringInfoString(&buffer, "session variable");
+ break;
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
@@ -5766,6 +5852,10 @@ getObjectIdentityParts(const ObjectAddress *object,
appendStringInfoString(&buffer,
" on schemas");
break;
+ case DEFACLOBJ_VARIABLE:
+ appendStringInfoString(&buffer,
+ " on session variables");
+ break;
}
if (objname)
@@ -6006,6 +6096,33 @@ getObjectIdentityParts(const ObjectAddress *object,
}
break;
+ case VariableRelationId:
+ {
+ char *schema;
+ char *varname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ schema = get_namespace_name_or_temp(varform->varnamespace);
+ varname = NameStr(varform->varname);
+
+ appendStringInfo(&buffer, "%s",
+ quote_qualified_identifier(schema, varname));
+
+ if (objname)
+ *objname = list_make2(schema, pstrdup(varname));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
diff --git a/src/backend/catalog/pg_shdepend.c b/src/backend/catalog/pg_shdepend.c
index 536191284e8..c6fd1fa074f 100644
--- a/src/backend/catalog/pg_shdepend.c
+++ b/src/backend/catalog/pg_shdepend.c
@@ -46,6 +46,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
@@ -1714,6 +1715,7 @@ shdepReassignOwned_Owner(Form_pg_shdepend sdepForm, Oid newrole)
case DatabaseRelationId:
case TSConfigRelationId:
case TSDictionaryRelationId:
+ case VariableRelationId:
AlterObjectOwner_internal(sdepForm->classid,
sdepForm->objid,
newrole);
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
new file mode 100644
index 00000000000..29d967a2d5b
--- /dev/null
+++ b/src/backend/catalog/pg_variable.c
@@ -0,0 +1,251 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.c
+ * session variables
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/catalog/pg_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "catalog/dependency.h"
+#include "catalog/indexing.h"
+#include "catalog/namespace.h"
+#include "catalog/objectaccess.h"
+#include "catalog/pg_collation.h"
+#include "catalog/pg_namespace.h"
+#include "catalog/pg_variable.h"
+#include "miscadmin.h"
+#include "parser/parse_type.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+static ObjectAddress create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists);
+
+
+/*
+ * Creates entry in pg_variable table
+ */
+static ObjectAddress
+create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists)
+{
+ Acl *varacl;
+ NameData varname;
+ bool nulls[Natts_pg_variable];
+ Datum values[Natts_pg_variable];
+ Relation rel;
+ HeapTuple tup;
+ TupleDesc tupdesc;
+ ObjectAddress myself,
+ referenced;
+ ObjectAddresses *addrs;
+ Oid varid;
+
+ Assert(varName);
+ Assert(OidIsValid(varNamespace));
+ Assert(OidIsValid(varType));
+ Assert(OidIsValid(varOwner));
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ /*
+ * Check for duplicates. Note that this does not really prevent
+ * duplicates, it's here just to provide nicer error message in common
+ * case. The real protection is the unique key on the catalog.
+ */
+ if (SearchSysCacheExists2(VARIABLENAMENSP,
+ PointerGetDatum(varName),
+ ObjectIdGetDatum(varNamespace)))
+ {
+ if (if_not_exists)
+ ereport(NOTICE,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists, skipping",
+ varName)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists",
+ varName)));
+
+ table_close(rel, RowExclusiveLock);
+
+ return InvalidObjectAddress;
+ }
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, false, sizeof(nulls));
+
+ namestrcpy(&varname, varName);
+
+ varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
+
+ values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
+ values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
+ values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
+ values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
+ values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
+ values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+
+ varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
+ varNamespace);
+ if (varacl != NULL)
+ values[Anum_pg_variable_varacl - 1] = PointerGetDatum(varacl);
+ else
+ nulls[Anum_pg_variable_varacl - 1] = true;
+
+ tupdesc = RelationGetDescr(rel);
+
+ tup = heap_form_tuple(tupdesc, values, nulls);
+ CatalogTupleInsert(rel, tup);
+ Assert(OidIsValid(varid));
+
+ addrs = new_object_addresses();
+
+ ObjectAddressSet(myself, VariableRelationId, varid);
+
+ /* dependency on namespace */
+ ObjectAddressSet(referenced, NamespaceRelationId, varNamespace);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on used type */
+ ObjectAddressSet(referenced, TypeRelationId, varType);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on collation */
+ if (OidIsValid(varCollation) &&
+ varCollation != DEFAULT_COLLATION_OID)
+ {
+ ObjectAddressSet(referenced, CollationRelationId, varCollation);
+ add_exact_object_address(&referenced, addrs);
+ }
+
+ record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
+ free_object_addresses(addrs);
+
+ /* dependency on owner */
+ recordDependencyOnOwner(VariableRelationId, varid, varOwner);
+
+ /* dependencies on roles mentioned in default ACL */
+ recordDependencyOnNewAcl(VariableRelationId, varid, 0, varOwner, varacl);
+
+ /* dependency on extension */
+ recordDependencyOnCurrentExtension(&myself, false);
+
+ heap_freetuple(tup);
+
+ /* post creation hook for new function */
+ InvokeObjectPostCreateHook(VariableRelationId, varid, 0);
+
+ table_close(rel, RowExclusiveLock);
+
+ return myself;
+}
+
+/*
+ * Creates a new variable
+ *
+ * Used by CREATE VARIABLE command
+ */
+ObjectAddress
+CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
+{
+ Oid namespaceid;
+ AclResult aclresult;
+ Oid typid;
+ int32 typmod;
+ Oid varowner = GetUserId();
+ Oid collation;
+ Oid typcollation;
+ ObjectAddress variable;
+
+ namespaceid =
+ RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL);
+
+ typenameTypeIdAndMod(pstate, stmt->typeName, &typid, &typmod);
+
+ /* disallow pseudotypes */
+ if (get_typtype(typid) == TYPTYPE_PSEUDO)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("session variable cannot be pseudo-type %s",
+ format_type_be(typid))));
+
+ aclresult = object_aclcheck(TypeRelationId, typid, GetUserId(), ACL_USAGE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error_type(aclresult, typid);
+
+ typcollation = get_typcollation(typid);
+
+ if (stmt->collClause)
+ collation = LookupCollation(pstate,
+ stmt->collClause->collname,
+ stmt->collClause->location);
+ else
+ collation = typcollation;
+
+ /* complain if COLLATE is applied to an uncollatable type */
+ if (OidIsValid(collation) && !OidIsValid(typcollation))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("collations are not supported by type %s",
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->collClause->location)));
+
+ variable = create_variable(stmt->variable->relname,
+ namespaceid,
+ typid,
+ typmod,
+ varowner,
+ collation,
+ stmt->if_not_exists);
+
+ elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
+ stmt->variable->relname, variable.objectId);
+
+ return variable;
+}
+
+/*
+ * Drop variable by OID
+ */
+void
+DropVariableById(Oid varid)
+{
+ Relation rel;
+ HeapTuple tup;
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ CatalogTupleDelete(rel, &tup->t_self);
+
+ ReleaseSysCache(tup);
+
+ table_close(rel, RowExclusiveLock);
+}
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 78c1d4e1b84..67153cd8b94 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/collationcmds.h"
#include "commands/dbcommands.h"
@@ -140,6 +141,10 @@ report_namespace_conflict(Oid classId, const char *name, Oid nspOid)
Assert(OidIsValid(nspOid));
msgfmt = gettext_noop("text search configuration \"%s\" already exists in schema \"%s\"");
break;
+ case VariableRelationId:
+ Assert(OidIsValid(nspOid));
+ msgfmt = gettext_noop("session variable \"%s\" already exists in schema \"%s\"");
+ break;
default:
elog(ERROR, "unsupported object class: %u", classId);
break;
@@ -419,6 +424,7 @@ ExecRenameStmt(RenameStmt *stmt)
case OBJECT_TSTEMPLATE:
case OBJECT_PUBLICATION:
case OBJECT_SUBSCRIPTION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
Relation catalog;
@@ -559,6 +565,7 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt,
case OBJECT_TSDICTIONARY:
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
+ case OBJECT_VARIABLE:
{
Relation catalog;
Oid classId;
@@ -641,6 +648,7 @@ AlterObjectNamespace_oid(Oid classId, Oid objid, Oid nspOid,
case TSDictionaryRelationId:
case TSTemplateRelationId:
case TSConfigRelationId:
+ case VariableRelationId:
{
Relation catalog;
@@ -871,6 +879,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
case OBJECT_TABLESPACE:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
diff --git a/src/backend/commands/dropcmds.c b/src/backend/commands/dropcmds.c
index ceb9a229b63..ebb585dc4a1 100644
--- a/src/backend/commands/dropcmds.c
+++ b/src/backend/commands/dropcmds.c
@@ -476,6 +476,10 @@ does_not_exist_skipping(ObjectType objtype, Node *object)
msg = gettext_noop("publication \"%s\" does not exist, skipping");
name = strVal(object);
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("session variable \"%s\" does not exist, skipping");
+ name = NameListToString(castNode(List, object));
+ break;
case OBJECT_COLUMN:
case OBJECT_DATABASE:
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index edc2c988e29..1839c1f82c5 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -2149,6 +2149,8 @@ stringify_grant_objtype(ObjectType objtype)
return "TABLESPACE";
case OBJECT_TYPE:
return "TYPE";
+ case OBJECT_VARIABLE:
+ return "VARIABLE";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
@@ -2232,6 +2234,8 @@ stringify_adefprivs_objtype(ObjectType objtype)
return "TABLESPACES";
case OBJECT_TYPE:
return "TYPES";
+ case OBJECT_VARIABLE:
+ return "VARIABLES";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
diff --git a/src/backend/commands/seclabel.c b/src/backend/commands/seclabel.c
index cee5d7bbb9c..57b4e6719c2 100644
--- a/src/backend/commands/seclabel.c
+++ b/src/backend/commands/seclabel.c
@@ -92,6 +92,7 @@ SecLabelSupportsObjectType(ObjectType objtype)
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
case OBJECT_USER_MAPPING:
+ case OBJECT_VARIABLE:
return false;
/*
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 5823fce9340..ccf58e3de13 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -52,6 +52,7 @@
#include "catalog/pg_tablespace.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "catalog/storage.h"
#include "catalog/storage_xlog.h"
#include "catalog/toasting.h"
@@ -6823,6 +6824,7 @@ ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
* (possibly nested several levels deep in composite types, arrays, etc!).
* Eventually, we'd like to propagate the check or rewrite operation
* into such tables, but for now, just error out if we find any.
+ * Also, check if "typeOid" is used as type of some session variable.
*
* Caller should provide either the associated relation of a rowtype,
* or a type name (not both) for use in the error message, if any.
@@ -6886,6 +6888,45 @@ find_composite_type_dependencies(Oid typeOid, Relation origRelation,
continue;
}
+ /* check if the type is used as type of some session variable */
+ if (pg_depend->classid == VariableRelationId)
+ {
+ Oid varid = pg_depend->objid;
+
+ if (origTypeName)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ origTypeName,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter foreign table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_RELATION ||
+ origRelation->rd_rel->relkind == RELKIND_MATVIEW ||
+ origRelation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+
+ continue;
+ }
+
/* Else, ignore dependees that aren't relations */
if (pg_depend->classid != RelationRelationId)
continue;
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 3cb3ca1cca1..473d98ff062 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -53,6 +53,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_range.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablecmds.h"
#include "commands/typecmds.h"
@@ -3369,6 +3370,20 @@ get_rels_with_domain(Oid domainOid, LOCKMODE lockmode)
}
continue;
}
+ else if (pg_depend->classid == VariableRelationId)
+ {
+ /*
+ * We cannot to validate constraint inside session variables
+ * from other sessions, so better to fail if there are any
+ * session variable, that use this domain.
+ */
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter domain \"%s\" because session variable \"%s.%s\" uses it",
+ domainTypeName,
+ get_namespace_name(get_session_variable_namespace(pg_depend->objid)),
+ get_session_variable_name(pg_depend->objid))));
+ }
/* Else, ignore dependees that aren't user columns of relations */
/* (we assume system columns are never of domain types) */
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index d3887628d46..2de2022b281 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -52,6 +52,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_am.h"
#include "catalog/pg_trigger.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/trigger.h"
#include "gramparse.h"
@@ -285,8 +286,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
ConstraintsSetStmt CopyStmt CreateAsStmt CreateCastStmt
CreateDomainStmt CreateExtensionStmt CreateGroupStmt CreateOpClassStmt
CreateOpFamilyStmt AlterOpFamilyStmt CreatePLangStmt
- CreateSchemaStmt CreateSeqStmt CreateStmt CreateStatsStmt CreateTableSpaceStmt
- CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
+ CreateSchemaStmt CreateSeqStmt CreateSessionVarStmt CreateStmt CreateStatsStmt
+ CreateTableSpaceStmt CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
CreateAssertionStmt CreateTransformStmt CreateTrigStmt CreateEventTrigStmt
CreateUserStmt CreateUserMappingStmt CreateRoleStmt CreatePolicyStmt
CreatedbStmt DeclareCursorStmt DefineStmt DeleteStmt DiscardStmt DoStmt
@@ -783,8 +784,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
UESCAPE UNBOUNDED UNCONDITIONAL UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN
UNLISTEN UNLOGGED UNTIL UPDATE USER USING
- VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
- VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
+ VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARIABLE
+ VARIABLES VARYING VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
@@ -1050,6 +1051,7 @@ stmt:
| CreatePolicyStmt
| CreatePLangStmt
| CreateSchemaStmt
+ | CreateSessionVarStmt
| CreateSeqStmt
| CreateStmt
| CreateSubscriptionStmt
@@ -1592,6 +1594,7 @@ schema_stmt:
| CreateTrigStmt
| GrantStmt
| ViewStmt
+ | CreateSessionVarStmt
;
@@ -5245,6 +5248,34 @@ create_extension_opt_item:
}
;
+/*****************************************************************************
+ *
+ * QUERY :
+ * CREATE VARIABLE varname [AS] type
+ *
+ *****************************************************************************/
+
+CreateSessionVarStmt:
+ CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $3;
+ n->typeName = $5;
+ n->collClause = (CollateClause *) $6;
+ n->if_not_exists = false;
+ $$ = (Node *) n;
+ }
+ | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $6;
+ n->typeName = $8;
+ n->collClause = (CollateClause *) $9;
+ n->if_not_exists = true;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
@@ -7036,6 +7067,7 @@ object_type_any_name:
| TEXT_P SEARCH DICTIONARY { $$ = OBJECT_TSDICTIONARY; }
| TEXT_P SEARCH TEMPLATE { $$ = OBJECT_TSTEMPLATE; }
| TEXT_P SEARCH CONFIGURATION { $$ = OBJECT_TSCONFIGURATION; }
+ | VARIABLE { $$ = OBJECT_VARIABLE; }
;
/*
@@ -7912,6 +7944,14 @@ privilege_target:
n->objs = $2;
$$ = n;
}
+ | VARIABLE qualified_name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_OBJECT;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $2;
+ $$ = n;
+ }
| ALL TABLES IN_P SCHEMA name_list
{
PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
@@ -7957,6 +7997,14 @@ privilege_target:
n->objs = $5;
$$ = n;
}
+ | ALL VARIABLES IN_P SCHEMA name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_ALL_IN_SCHEMA;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $5;
+ $$ = n;
+ }
;
@@ -8154,6 +8202,7 @@ defacl_privilege_target:
| SEQUENCES { $$ = OBJECT_SEQUENCE; }
| TYPES_P { $$ = OBJECT_TYPE; }
| SCHEMAS { $$ = OBJECT_SCHEMA; }
+ | VARIABLES { $$ = OBJECT_VARIABLE; }
;
@@ -9942,6 +9991,24 @@ RenameStmt: ALTER AGGREGATE aggregate_with_argtypes RENAME TO name
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newname = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newname = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
opt_column: COLUMN
@@ -10303,6 +10370,24 @@ AlterObjectSchemaStmt:
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newschema = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newschema = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
/*****************************************************************************
@@ -10584,6 +10669,14 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec
n->newowner = $6;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name OWNER TO RoleSpec
+ {
+ AlterOwnerStmt *n = makeNode(AlterOwnerStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newowner = $6;
+ $$ = (Node *)n;
+ }
;
@@ -17993,6 +18086,8 @@ unreserved_keyword:
| VALIDATE
| VALIDATOR
| VALUE_P
+ | VARIABLE
+ | VARIABLES
| VARYING
| VERSION_P
| VIEW
@@ -18648,6 +18743,8 @@ bare_label_keyword:
| VALUE_P
| VALUES
| VARCHAR
+ | VARIABLE
+ | VARIABLES
| VARIADIC
| VERBOSE
| VERSION_P
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index eb7716cd84c..a7018d6628d 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -105,6 +105,7 @@ typedef struct
List *indexes; /* CREATE INDEX items */
List *triggers; /* CREATE TRIGGER items */
List *grants; /* GRANT items */
+ List *variables; /* CREATE VARIABLE items */
} CreateSchemaStmtContext;
@@ -4100,6 +4101,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.indexes = NIL;
cxt.triggers = NIL;
cxt.grants = NIL;
+ cxt.variables = NIL;
/*
* Run through each schema element in the schema element list. Separate
@@ -4168,6 +4170,15 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.grants = lappend(cxt.grants, element);
break;
+ case T_CreateSessionVarStmt:
+ {
+ CreateSessionVarStmt *elp = (CreateSessionVarStmt *) element;
+
+ setSchemaName(cxt.schemaname, &elp->variable->schemaname);
+ cxt.variables = lappend(cxt.variables, element);
+ }
+ break;
+
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(element));
@@ -4181,6 +4192,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
result = list_concat(result, cxt.indexes);
result = list_concat(result, cxt.triggers);
result = list_concat(result, cxt.grants);
+ result = list_concat(result, cxt.variables);
return result;
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 25fe3d58016..99a51877d34 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -23,6 +23,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_inherits.h"
+#include "catalog/pg_variable.h"
#include "catalog/toasting.h"
#include "commands/alter.h"
#include "commands/async.h"
@@ -182,6 +183,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CreateRangeStmt:
case T_CreateRoleStmt:
case T_CreateSchemaStmt:
+ case T_CreateSessionVarStmt:
case T_CreateSeqStmt:
case T_CreateStatsStmt:
case T_CreateStmt:
@@ -1389,6 +1391,10 @@ ProcessUtilitySlow(ParseState *pstate,
}
break;
+ case T_CreateSessionVarStmt:
+ address = CreateVariable(pstate, (CreateSessionVarStmt *) parsetree);
+ break;
+
/*
* ************* object creation / destruction **************
*/
@@ -2341,6 +2347,9 @@ AlterObjectTypeCommandTag(ObjectType objtype)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_ALTER_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_ALTER_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
break;
@@ -2649,6 +2658,9 @@ CreateCommandTag(Node *parsetree)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_DROP_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_DROP_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
@@ -3225,6 +3237,10 @@ CreateCommandTag(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ tag = CMDTAG_CREATE_VARIABLE;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
@@ -3759,6 +3775,10 @@ GetCommandLogLevel(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ lev = LOGSTMT_DDL;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index 6a76550a5e2..377de0b7c6b 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -31,6 +31,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/proclang.h"
#include "commands/tablespace.h"
@@ -129,6 +130,8 @@ static AclMode convert_type_priv_string(text *priv_type_text);
static AclMode convert_parameter_priv_string(text *priv_text);
static AclMode convert_largeobject_priv_string(text *priv_text);
static AclMode convert_role_priv_string(text *priv_type_text);
+static Oid convert_session_variable_name(text *varname);
+static AclMode convert_session_variable_priv_string(text *priv_type_text);
static AclResult pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode);
static void RoleMembershipCacheCallback(Datum arg, int cacheid, uint32 hashvalue);
@@ -851,6 +854,10 @@ acldefault(ObjectType objtype, Oid ownerId)
world_default = ACL_NO_RIGHTS;
owner_default = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ world_default = ACL_NO_RIGHTS;
+ owner_default = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", (int) objtype);
world_default = ACL_NO_RIGHTS; /* keep compiler quiet */
@@ -948,6 +955,9 @@ acldefault_sql(PG_FUNCTION_ARGS)
case 'T':
objtype = OBJECT_TYPE;
break;
+ case 'V':
+ objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type abbreviation: %c", objtypec);
}
@@ -5016,6 +5026,217 @@ pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode)
return ACLCHECK_NO_PRIV;
}
+/*
+ * has_session_variable_privilege variants
+ * These are all named "has_session_variable_privilege" at the SQL level.
+ * They take various combinations of variable name, variable OID,
+ * user name, user OID, or implicit user = current_user.
+ *
+ * The result is a boolean value: true if user has the indicated
+ * privilege, false if not, or NULL if session variable doesn't
+ * exists.
+ */
+
+/*
+ * has_session_variable_privilege_name_name
+ * Check user privileges on a session variable given
+ * name username, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_name(PG_FUNCTION_ARGS)
+{
+ Name rolename = PG_GETARG_NAME(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*rolename));
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name
+ * Check user privileges on a session variable given
+ * text session variable and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_name(PG_FUNCTION_ARGS)
+{
+ text *varname = PG_GETARG_TEXT_PP(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name_id
+ * Check user privileges on a session variable given
+ * name usename, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_id(PG_FUNCTION_ARGS)
+{
+ Name username = PG_GETARG_NAME(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*username));
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id
+ * Check user privileges on a session variable given
+ * session variable oid, and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_id(PG_FUNCTION_ARGS)
+{
+ Oid varid = PG_GETARG_OID(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_name
+ * Check user privileges on a session variable given
+ * roleid, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_name(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_id
+ * Check user privileges on a session variable given
+ * roleid, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_id(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * Given a session variable name expressed as a string, look it up and return
+ * Oid
+ */
+static Oid
+convert_session_variable_name(text *varname)
+{
+ return LookupVariableFromNameList(textToQualifiedNameList(varname), true);
+}
+
+/*
+ * convert_variable_priv_string
+ * Convert text string to AclMode value.
+ */
+static AclMode
+convert_session_variable_priv_string(text *priv_type_text)
+{
+ static const priv_map session_variable_priv_map[] = {
+ {"SELECT", ACL_SELECT},
+ {"SELECT WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_SELECT)},
+ {"UPDATE", ACL_UPDATE},
+ {"UPDATE WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_UPDATE)},
+ {NULL, 0}
+ };
+
+ return convert_any_priv_string(priv_type_text, session_variable_priv_map);
+}
/*
* initialization function (called by InitPostgres)
diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index bcfa5cb4add..f19b8bd4dc9 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -39,6 +39,7 @@
#include "catalog/pg_subscription.h"
#include "catalog/pg_transform.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "utils/array.h"
@@ -3741,3 +3742,115 @@ get_subscription_name(Oid subid, bool missing_ok)
return subname;
}
+
+/* ---------- PG_VARIABLE CACHE ---------- */
+
+/*
+ * get_varname_varid
+ * Given name and namespace of variable, look up the OID.
+ */
+Oid
+get_varname_varid(const char *varname, Oid varnamespace)
+{
+ return GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(varnamespace));
+}
+
+/*
+ * get_session_variable_name
+ * Returns a palloc'd copy of the name of a given session variable.
+ */
+char *
+get_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = pstrdup(NameStr(varform->varname));
+
+ ReleaseSysCache(tup);
+
+ return varname;
+}
+
+/*
+ * get_session_variable_namespace
+ * Returns the pg_namespace OID associated with a given session variable.
+ */
+Oid
+get_session_variable_namespace(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varnamespace = varform->varnamespace;
+
+ ReleaseSysCache(tup);
+
+ return varnamespace;
+}
+
+/*
+ * Returns the type of the given session variable.
+ */
+Oid
+get_session_variable_type(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid vartype;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ vartype = varform->vartype;
+
+ ReleaseSysCache(tup);
+
+ return vartype;
+}
+
+/*
+ * Returns the type, typmod and collid of the given session variable.
+ */
+void
+get_session_variable_type_typmod_collid(Oid varid, Oid *typid, int32 *typmod,
+ Oid *collid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ *typid = varform->vartype;
+ *typmod = varform->vartypmod;
+ *collid = varform->varcollation;
+
+ ReleaseSysCache(tup);
+}
diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c
index 56b6c368acf..ba6b19dc9af 100644
--- a/src/bin/pg_dump/common.c
+++ b/src/bin/pg_dump/common.c
@@ -246,6 +246,9 @@ getSchemaData(Archive *fout, int *numTablesPtr)
pg_log_info("reading subscription membership of tables");
getSubscriptionTables(fout);
+ pg_log_info("reading variables");
+ getVariables(fout);
+
free(inhinfo); /* not needed any longer */
*numTablesPtr = numTables;
diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index 5ae77f76367..5161ee780ea 100644
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -511,6 +511,12 @@ do { \
CONVERT_PRIV('r', "SELECT");
CONVERT_PRIV('w', "UPDATE");
}
+ else if (strcmp(type, "VARIABLE") == 0 ||
+ strcmp(type, "VARIABLES") == 0)
+ {
+ CONVERT_PRIV('r', "SELECT");
+ CONVERT_PRIV('w', "UPDATE");
+ }
else
abort();
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index f0f19bb0b29..44eed03a2ff 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -132,12 +132,14 @@ typedef struct _restoreOptions
int selFunction;
int selTrigger;
int selTable;
+ int selVariable;
SimpleStringList indexNames;
SimpleStringList functionNames;
SimpleStringList schemaNames;
SimpleStringList schemaExcludeNames;
SimpleStringList triggerNames;
SimpleStringList tableNames;
+ SimpleStringList variableNames;
int useDB;
ConnParams cparams; /* parameters to use if useDB */
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index b9d7ab98c3e..d533345ea98 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -3103,6 +3103,14 @@ _tocEntryRequired(TocEntry *te, teSection curSection, ArchiveHandle *AH)
!simple_string_list_member(&ropt->triggerNames, te->tag))
return 0;
}
+ else if (strcmp(te->desc, "VARIABLE") == 0)
+ {
+ if (!ropt->selVariable)
+ return 0;
+ if (ropt->variableNames.head != NULL &&
+ !simple_string_list_member(&ropt->variableNames, te->tag))
+ return 0;
+ }
else
return 0;
}
@@ -3652,6 +3660,7 @@ _getObjectDescription(PQExpBuffer buf, const TocEntry *te)
strcmp(type, "TEXT SEARCH DICTIONARY") == 0 ||
strcmp(type, "TEXT SEARCH CONFIGURATION") == 0 ||
strcmp(type, "TYPE") == 0 ||
+ strcmp(type, "VARIABLE") == 0 ||
strcmp(type, "VIEW") == 0 ||
/* non-schema-specified objects */
strcmp(type, "DATABASE") == 0 ||
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index ca15b40939c..8f8f1185f16 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -364,6 +364,7 @@ static void dumpPublication(Archive *fout, const PublicationInfo *pubinfo);
static void dumpPublicationTable(Archive *fout, const PublicationRelInfo *pubrinfo);
static void dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo);
static void dumpSubscriptionTable(Archive *fout, const SubRelInfo *subrinfo);
+static void dumpVariable(Archive *fout, const VariableInfo *varinfo);
static void dumpDatabase(Archive *fout);
static void dumpDatabaseConfig(Archive *AH, PQExpBuffer outbuf,
const char *dbname, Oid dboid);
@@ -5421,6 +5422,188 @@ get_next_possible_free_pg_type_oid(Archive *fout, PQExpBuffer upgrade_query)
return next_possible_free_oid;
}
+/*
+ * getVariables
+ * get information about variables
+ */
+void
+getVariables(Archive *fout)
+{
+ PQExpBuffer query;
+ PGresult *res;
+ VariableInfo *varinfo;
+ int i_tableoid;
+ int i_oid;
+ int i_varname;
+ int i_varnamespace;
+ int i_vartype;
+ int i_vartypname;
+ int i_varowner;
+ int i_varcollation;
+ int i_varacl;
+ int i_acldefault;
+ int i,
+ ntups;
+
+ if (fout->remoteVersion < 180000)
+ return;
+
+ query = createPQExpBuffer();
+
+ /* get the variables in current database */
+ appendPQExpBuffer(query,
+ "SELECT v.tableoid, v.oid, v.varname,\n"
+ " v.varnamespace, v.vartype,\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n"
+ " CASE WHEN v.varcollation <> t.typcollation "
+ " THEN v.varcollation\n"
+ " ELSE 0\n"
+ " END AS varcollation,\n"
+ " v.varowner, v.varacl,\n"
+ " acldefault('V', v.varowner) AS acldefault\n"
+ "FROM pg_catalog.pg_variable v\n"
+ "JOIN pg_catalog.pg_type t "
+ "ON (v.vartype = t.oid)");
+
+ res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK);
+
+ ntups = PQntuples(res);
+
+ i_tableoid = PQfnumber(res, "tableoid");
+ i_oid = PQfnumber(res, "oid");
+ i_varname = PQfnumber(res, "varname");
+ i_varnamespace = PQfnumber(res, "varnamespace");
+ i_vartype = PQfnumber(res, "vartype");
+ i_vartypname = PQfnumber(res, "vartypname");
+ i_varcollation = PQfnumber(res, "varcollation");
+
+ i_varowner = PQfnumber(res, "varowner");
+ i_varacl = PQfnumber(res, "varacl");
+ i_acldefault = PQfnumber(res, "acldefault");
+
+ varinfo = pg_malloc(ntups * sizeof(VariableInfo));
+
+ for (i = 0; i < ntups; i++)
+ {
+ TypeInfo *vtype;
+
+ varinfo[i].dobj.objType = DO_VARIABLE;
+ varinfo[i].dobj.catId.tableoid =
+ atooid(PQgetvalue(res, i, i_tableoid));
+ varinfo[i].dobj.catId.oid = atooid(PQgetvalue(res, i, i_oid));
+ AssignDumpId(&varinfo[i].dobj);
+ varinfo[i].dobj.name = pg_strdup(PQgetvalue(res, i, i_varname));
+ varinfo[i].dobj.namespace =
+ findNamespace(atooid(PQgetvalue(res, i, i_varnamespace)));
+
+ varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype));
+ varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname));
+ varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
+
+ varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
+ varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
+ varinfo[i].dacl.privtype = 0;
+ varinfo[i].dacl.initprivs = NULL;
+ varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner));
+
+ /* do not try to dump ACL if no ACL exists */
+ if (!PQgetisnull(res, i, i_varacl))
+ varinfo[i].dobj.components |= DUMP_COMPONENT_ACL;
+
+ if (strlen(varinfo[i].rolname) == 0)
+ pg_log_warning("owner of variable \"%s\" appears to be invalid",
+ varinfo[i].dobj.name);
+
+ /* decide whether we want to dump it */
+ selectDumpableObject(&(varinfo[i].dobj), fout);
+
+ vtype = findTypeByOid(varinfo[i].vartype);
+ addObjectDependency(&varinfo[i].dobj, vtype->dobj.dumpId);
+ }
+ PQclear(res);
+
+ destroyPQExpBuffer(query);
+}
+
+/*
+ * dumpVariable
+ * dump the definition of the given session variable
+ */
+static void
+dumpVariable(Archive *fout, const VariableInfo *varinfo)
+{
+ DumpOptions *dopt = fout->dopt;
+
+ PQExpBuffer delq;
+ PQExpBuffer query;
+ char *qualvarname;
+ const char *vartypname;
+ Oid varcollation;
+
+ /* skip if not to be dumped */
+ if (!varinfo->dobj.dump || !dopt->dumpSchema)
+ return;
+
+ delq = createPQExpBuffer();
+ query = createPQExpBuffer();
+
+ qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
+ vartypname = varinfo->vartypname;
+ varcollation = varinfo->varcollation;
+
+ appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
+ qualvarname);
+
+ appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s",
+ qualvarname, vartypname);
+
+ if (OidIsValid(varcollation))
+ {
+ CollInfo *coll;
+
+ coll = findCollationByOid(varcollation);
+ if (coll)
+ appendPQExpBuffer(query, " COLLATE %s",
+ fmtQualifiedDumpable(coll));
+ }
+
+ appendPQExpBuffer(query, ";\n");
+
+ if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
+ ArchiveEntry(fout, varinfo->dobj.catId, varinfo->dobj.dumpId,
+ ARCHIVE_OPTS(.tag = varinfo->dobj.name,
+ .namespace = varinfo->dobj.namespace->dobj.name,
+ .owner = varinfo->rolname,
+ .description = "VARIABLE",
+ .section = SECTION_PRE_DATA,
+ .createStmt = query->data,
+ .dropStmt = delq->data));
+
+ /* dump comment if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_COMMENT)
+ dumpComment(fout, "VARIABLE", qualvarname,
+ NULL, varinfo->rolname,
+ varinfo->dobj.catId, 0, varinfo->dobj.dumpId);
+
+ /* dump ACL if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_ACL)
+ {
+ char *qvarname = pg_strdup(fmtId(varinfo->dobj.name));
+
+ dumpACL(fout, varinfo->dobj.dumpId, InvalidDumpId, "VARIABLE",
+ qvarname, NULL,
+ varinfo->dobj.namespace->dobj.name, NULL, varinfo->rolname,
+ &varinfo->dacl);
+
+ free(qvarname);
+ }
+
+ destroyPQExpBuffer(delq);
+ destroyPQExpBuffer(query);
+
+ free(qualvarname);
+}
+
static void
binary_upgrade_set_type_oids_by_type_oid(Archive *fout,
PQExpBuffer upgrade_buffer,
@@ -10746,6 +10929,9 @@ dumpDumpableObject(Archive *fout, DumpableObject *dobj)
case DO_SUBSCRIPTION_REL:
dumpSubscriptionTable(fout, (const SubRelInfo *) dobj);
break;
+ case DO_VARIABLE:
+ dumpVariable(fout, (VariableInfo *) dobj);
+ break;
case DO_PRE_DATA_BOUNDARY:
case DO_POST_DATA_BOUNDARY:
/* never dumped, nothing to do */
@@ -15197,6 +15383,9 @@ dumpDefaultACL(Archive *fout, const DefaultACLInfo *daclinfo)
case DEFACLOBJ_NAMESPACE:
type = "SCHEMAS";
break;
+ case DEFACLOBJ_VARIABLE:
+ type = "VARIABLES";
+ break;
default:
/* shouldn't get here */
pg_fatal("unrecognized object type in default privileges: %d",
@@ -18919,6 +19108,7 @@ addBoundaryDependencies(DumpableObject **dobjs, int numObjs,
case DO_CONVERSION:
case DO_TABLE:
case DO_TABLE_ATTACH:
+ case DO_VARIABLE:
case DO_ATTRDEF:
case DO_PROCLANG:
case DO_CAST:
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index 7139c88a69a..125384cf3f0 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -53,6 +53,7 @@ typedef enum
DO_TABLE,
DO_TABLE_ATTACH,
DO_ATTRDEF,
+ DO_VARIABLE,
DO_INDEX,
DO_INDEX_ATTACH,
DO_STATSEXT,
@@ -708,6 +709,19 @@ typedef struct _SubRelInfo
char *srsublsn;
} SubRelInfo;
+/*
+ * The VariableInfo struct is used to represent session variables
+ */
+typedef struct _VariableInfo
+{
+ DumpableObject dobj;
+ DumpableAcl dacl;
+ Oid vartype;
+ char *vartypname;
+ Oid varcollation;
+ const char *rolname; /* name of owner, or empty string */
+} VariableInfo;
+
/*
* common utility functions
*/
@@ -791,5 +805,6 @@ extern void getPublicationTables(Archive *fout, TableInfo tblinfo[],
int numTables);
extern void getSubscriptions(Archive *fout);
extern void getSubscriptionTables(Archive *fout);
+extern void getVariables(Archive *fout);
#endif /* PG_DUMP_H */
diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c
index dc9a28924bd..842973f1128 100644
--- a/src/bin/pg_dump/pg_dump_sort.c
+++ b/src/bin/pg_dump/pg_dump_sort.c
@@ -77,6 +77,7 @@ enum dbObjectTypePriorities
PRIO_DUMMY_TYPE,
PRIO_ATTRDEF,
PRIO_LARGE_OBJECT,
+ PRIO_VARIABLE,
PRIO_PRE_DATA_BOUNDARY, /* boundary! */
PRIO_TABLE_DATA,
PRIO_SEQUENCE_SET,
@@ -118,6 +119,7 @@ static const int dbObjectTypePriority[] =
[DO_TABLE] = PRIO_TABLE,
[DO_TABLE_ATTACH] = PRIO_TABLE_ATTACH,
[DO_ATTRDEF] = PRIO_ATTRDEF,
+ [DO_VARIABLE] = PRIO_VARIABLE,
[DO_INDEX] = PRIO_INDEX,
[DO_INDEX_ATTACH] = PRIO_INDEX_ATTACH,
[DO_STATSEXT] = PRIO_STATSEXT,
@@ -1500,6 +1502,10 @@ describeDumpableObject(DumpableObject *obj, char *buf, int bufsize)
"POST-DATA BOUNDARY (ID %d)",
obj->dumpId);
return;
+ case DO_VARIABLE:
+ snprintf(buf, bufsize,
+ "VARIABLE %s (ID %d OID %u)",
+ obj->name, obj->dumpId, obj->catId.oid);
}
/* shouldn't get here */
snprintf(buf, bufsize,
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index bc5d9222a20..b84dcf0cab9 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -854,6 +854,16 @@ my %tests = (
unlike => { no_privs => 1, },
},
+ 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC'
+ => {
+ create_order => 56,
+ create_sql => 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;',
+ regexp => qr/^
+ \QALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;\E/xm,
+ like => { %full_runs, section_post_data => 1, },
+ unlike => { no_privs => 1, },
+ },
+
'ALTER ROLE regress_dump_test_role' => {
regexp => qr/^
\QALTER ROLE regress_dump_test_role WITH \E
@@ -1739,6 +1749,23 @@ my %tests = (
},
},
+ 'COMMENT ON VARIABLE dump_test.variable1' => {
+ create_order => 71,
+ create_sql => 'COMMENT ON VARIABLE dump_test.variable1
+ IS \'comment on variable\';',
+ regexp =>
+ qr/^\QCOMMENT ON VARIABLE dump_test.variable1 IS 'comment on variable';\E/m,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'COPY test_table' => {
create_order => 4,
create_sql => 'INSERT INTO dump_test.test_table (col1) '
@@ -4009,6 +4036,24 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable1 AS integer;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable1 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
@@ -4471,6 +4516,25 @@ my %tests = (
like => {},
},
+ 'GRANT SELECT ON VARIABLE dump_test.variable1' => {
+ create_order => 73,
+ create_sql =>
+ 'GRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;',
+ regexp => qr/^
+ \QGRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;\E
+ /xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ no_privs => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'REFRESH MATERIALIZED VIEW matview' => {
regexp => qr/^\QREFRESH MATERIALIZED VIEW dump_test.matview;\E/m,
like =>
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 26dfdde195a..6b870e2fc60 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -1097,6 +1097,9 @@ exec_command_d(PsqlScanState scan_state, bool active_branch, const char *cmd)
break;
}
break;
+ case 'V': /* Variables */
+ success = listVariables(pattern, show_verbose);
+ break;
case 'x': /* Extensions */
if (show_verbose)
success = listExtensionContents(pattern);
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 3b7ba66fad0..576ac986ef9 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -1222,7 +1222,7 @@ listDefaultACLs(const char *pattern)
printfPQExpBuffer(&buf,
"SELECT pg_catalog.pg_get_userbyid(d.defaclrole) AS \"%s\",\n"
" n.nspname AS \"%s\",\n"
- " CASE d.defaclobjtype WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
+ " CASE d.defaclobjtype WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
" ",
gettext_noop("Owner"),
gettext_noop("Schema"),
@@ -1236,6 +1236,8 @@ listDefaultACLs(const char *pattern)
gettext_noop("type"),
DEFACLOBJ_NAMESPACE,
gettext_noop("schema"),
+ DEFACLOBJ_VARIABLE,
+ gettext_noop("session variable"),
gettext_noop("Type"));
printACLColumn(&buf, "d.defaclacl");
@@ -5318,6 +5320,102 @@ error_return:
return false;
}
+/*
+ * \dV
+ *
+ * listVariables()
+ */
+bool
+listVariables(const char *pattern, bool verbose)
+{
+ PQExpBufferData buf;
+ PGresult *res;
+ printQueryOpt myopt = pset.popt;
+ static const bool translate_columns[] = {false, false, false, false, false, false, false};
+
+ if (pset.sversion < 180000)
+ {
+ char sverbuf[32];
+
+ pg_log_error("The server (version %s) does not support session variables.",
+ formatPGVersionNumber(pset.sversion, false,
+ sverbuf, sizeof(sverbuf)));
+ return true;
+ }
+
+ initPQExpBuffer(&buf);
+
+ printfPQExpBuffer(&buf,
+ "SELECT n.nspname as \"%s\",\n"
+ " v.varname as \"%s\",\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n"
+ " (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
+ " WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
+ " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n",
+ gettext_noop("Schema"),
+ gettext_noop("Name"),
+ gettext_noop("Type"),
+ gettext_noop("Collation"),
+ gettext_noop("Owner"));
+
+ if (verbose)
+ {
+ appendPQExpBufferStr(&buf, ",\n ");
+ printACLColumn(&buf, "v.varacl");
+ appendPQExpBuffer(&buf,
+ ",\n pg_catalog.obj_description(v.oid, 'pg_variable') AS \"%s\"",
+ gettext_noop("Description"));
+ }
+
+ appendPQExpBufferStr(&buf,
+ "\nFROM pg_catalog.pg_variable v"
+ "\n LEFT JOIN pg_catalog.pg_namespace n ON n.oid = v.varnamespace");
+
+ appendPQExpBufferStr(&buf, "\nWHERE true\n");
+ if (!pattern)
+ appendPQExpBufferStr(&buf, " AND n.nspname <> 'pg_catalog'\n"
+ " AND n.nspname <> 'information_schema'\n");
+
+ if (!validateSQLNamePattern(&buf, pattern, true, false,
+ "n.nspname", "v.varname", NULL,
+ "pg_catalog.pg_variable_is_visible(v.oid)",
+ NULL, 3))
+ return false;
+
+ appendPQExpBufferStr(&buf, "ORDER BY 1,2;");
+
+ res = PSQLexec(buf.data);
+ termPQExpBuffer(&buf);
+ if (!res)
+ return false;
+
+ /*
+ * Most functions in this file are content to print an empty table when
+ * there are no matching objects. We intentionally deviate from that
+ * here, but only in !quiet mode, for historical reasons.
+ */
+ if (PQntuples(res) == 0 && !pset.quiet)
+ {
+ if (pattern)
+ pg_log_error("Did not find any session variable named \"%s\".",
+ pattern);
+ else
+ pg_log_error("Did not find any session variables.");
+ }
+ else
+ {
+ myopt.nullPrint = NULL;
+ myopt.title = _("List of variables");
+ myopt.translate_header = true;
+ myopt.translate_columns = translate_columns;
+ myopt.n_translate_columns = lengthof(translate_columns);
+
+ printQuery(res, &myopt, pset.queryFout, false, pset.logfile);
+ }
+
+ PQclear(res);
+ return true;
+}
/*
* \dFp
diff --git a/src/bin/psql/describe.h b/src/bin/psql/describe.h
index 18ecaa60949..55ced4aab7b 100644
--- a/src/bin/psql/describe.h
+++ b/src/bin/psql/describe.h
@@ -149,4 +149,7 @@ extern bool listOpFamilyFunctions(const char *access_method_pattern,
/* \dl or \lo_list */
extern bool listLargeObjects(bool verbose);
+/* \dV */
+extern bool listVariables(const char *pattern, bool varbose);
+
#endif /* DESCRIBE_H */
diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index da8e1ade5df..9a02a0986d4 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -266,6 +266,7 @@ slashUsage(unsigned short int pager)
HELP0(" \\dT[Sx+] [PATTERN] list data types\n");
HELP0(" \\du[Sx+] [PATTERN] list roles\n");
HELP0(" \\dv[Sx+] [PATTERN] list views\n");
+ HELP0(" \\dV[x+] [PATTERN] list session variables\n");
HELP0(" \\dx[x+] [PATTERN] list extensions\n");
HELP0(" \\dX[x] [PATTERN] list extended statistics\n");
HELP0(" \\dy[x+] [PATTERN] list event triggers\n");
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index a9a81ab3c14..c6a1bb09f3f 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -970,6 +970,13 @@ static const SchemaQuery Query_for_trigger_of_table = {
.refnamespace = "c1.relnamespace",
};
+static const SchemaQuery Query_for_list_of_variables = {
+ .min_server_version = 180000,
+ .catname = "pg_catalog.pg_variable v",
+ .viscondition = "pg_catalog.pg_variable_is_visible(v.oid)",
+ .namespace = "v.varnamespace",
+ .result = "v.varname",
+};
/*
* Queries to get lists of names of various kinds of things, possibly
@@ -1304,6 +1311,7 @@ static const pgsql_thing_t words_after_create[] = {
* TABLE ... */
{"USER", Query_for_list_of_roles, NULL, NULL, Keywords_for_user_thing},
{"USER MAPPING FOR", NULL, NULL, NULL},
+ {"VARIABLE", NULL, NULL, &Query_for_list_of_variables},
{"VIEW", NULL, NULL, &Query_for_list_of_views},
{NULL} /* end of list */
};
@@ -1869,7 +1877,7 @@ psql_completion(const char *text, int start, int end)
"\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL",
"\\dm", "\\dn", "\\do", "\\dO", "\\dp", "\\dP", "\\dPi", "\\dPt",
"\\drds", "\\drg", "\\dRs", "\\dRp", "\\ds",
- "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy",
+ "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy", "\\dV",
"\\echo", "\\edit", "\\ef", "\\elif", "\\else", "\\encoding",
"\\endif", "\\errverbose", "\\ev",
"\\f",
@@ -2560,6 +2568,9 @@ match_previous_words(int pattern_id,
"ALL");
else if (Matches("ALTER", "SYSTEM", "SET", MatchAny))
COMPLETE_WITH("TO");
+ /* ALTER VARIABLE <name> */
+ else if (Matches("ALTER", "VARIABLE", MatchAny))
+ COMPLETE_WITH("OWNER TO", "RENAME TO", "SET SCHEMA");
/* ALTER VIEW <name> */
else if (Matches("ALTER", "VIEW", MatchAny))
COMPLETE_WITH("ALTER COLUMN", "OWNER TO", "RENAME", "RESET", "SET");
@@ -3140,7 +3151,7 @@ match_previous_words(int pattern_id,
"ROUTINE", "RULE", "SCHEMA", "SEQUENCE", "SERVER",
"STATISTICS", "SUBSCRIPTION", "TABLE",
"TABLESPACE", "TEXT SEARCH", "TRANSFORM FOR",
- "TRIGGER", "TYPE", "VIEW");
+ "TRIGGER", "TYPE", "VARIABLE", "VIEW");
else if (Matches("COMMENT", "ON", "ACCESS", "METHOD"))
COMPLETE_WITH_QUERY(Query_for_list_of_access_methods);
else if (Matches("COMMENT", "ON", "CONSTRAINT"))
@@ -3950,6 +3961,13 @@ match_previous_words(int pattern_id,
else if (TailMatches("=", MatchAnyExcept("*)")))
COMPLETE_WITH(",", ")");
}
+/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
+ /* Complete CREATE VARIABLE <name> with AS */
+ else if (TailMatches("CREATE", "VARIABLE", MatchAny))
+ COMPLETE_WITH("AS");
+ else if (TailMatches("VARIABLE", MatchAny, "AS"))
+ /* Complete CREATE VARIABLE <name> with AS types */
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
/* CREATE VIEW --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE [ OR REPLACE ] VIEW <name> with AS or WITH */
@@ -4227,6 +4245,12 @@ match_previous_words(int pattern_id,
else if (Matches("DROP", "TRANSFORM", "FOR", MatchAny, "LANGUAGE", MatchAny))
COMPLETE_WITH("CASCADE", "RESTRICT");
+ /* DROP VARIABLE */
+ else if (Matches("DROP", "VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ else if (Matches("DROP", "VARIABLE", MatchAny))
+ COMPLETE_WITH("CASCADE", "RESTRICT");
+
/* EXECUTE */
else if (Matches("EXECUTE"))
COMPLETE_WITH_QUERY(Query_for_list_of_prepared_statements);
@@ -4428,7 +4452,7 @@ match_previous_words(int pattern_id,
* objects supported.
*/
if (HeadMatches("ALTER", "DEFAULT", "PRIVILEGES"))
- COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS");
+ COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS", "VARIABLES");
else
COMPLETE_WITH_SCHEMA_QUERY_PLUS(Query_for_list_of_grantables,
"ALL FUNCTIONS IN SCHEMA",
@@ -4436,6 +4460,7 @@ match_previous_words(int pattern_id,
"ALL ROUTINES IN SCHEMA",
"ALL SEQUENCES IN SCHEMA",
"ALL TABLES IN SCHEMA",
+ "ALL VARIABLES IN SCHEMA",
"DATABASE",
"DOMAIN",
"FOREIGN DATA WRAPPER",
@@ -4450,7 +4475,8 @@ match_previous_words(int pattern_id,
"SEQUENCE",
"TABLE",
"TABLESPACE",
- "TYPE");
+ "TYPE",
+ "VARIABLE");
}
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "ALL") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "ALL"))
@@ -4458,7 +4484,8 @@ match_previous_words(int pattern_id,
"PROCEDURES IN SCHEMA",
"ROUTINES IN SCHEMA",
"SEQUENCES IN SCHEMA",
- "TABLES IN SCHEMA");
+ "TABLES IN SCHEMA",
+ "VARIABLES IN SCHEMA");
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "FOREIGN") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "FOREIGN"))
COMPLETE_WITH("DATA WRAPPER", "SERVER");
@@ -4494,6 +4521,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_tablespaces);
else if (TailMatches("TYPE"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
+ else if (TailMatches("VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatches("GRANT", MatchAny, MatchAny, MatchAny))
COMPLETE_WITH("TO");
else
@@ -4796,7 +4825,7 @@ match_previous_words(int pattern_id,
/* PREPARE xx AS */
else if (Matches("PREPARE", MatchAny, "AS"))
- COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM");
+ COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM", "LET");
/*
* PREPARE TRANSACTION is missing on purpose. It's intended for transaction
@@ -5278,6 +5307,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_roles);
else if (TailMatchesCS("\\dv*"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_views);
+ else if (TailMatchesCS("\\dV*"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatchesCS("\\dx*"))
COMPLETE_WITH_QUERY(Query_for_list_of_extensions);
else if (TailMatchesCS("\\dX*"))
diff --git a/src/include/catalog/Makefile b/src/include/catalog/Makefile
index 2bbc7805fe3..f98760de635 100644
--- a/src/include/catalog/Makefile
+++ b/src/include/catalog/Makefile
@@ -81,7 +81,8 @@ CATALOG_HEADERS := \
pg_publication_namespace.h \
pg_publication_rel.h \
pg_subscription.h \
- pg_subscription_rel.h
+ pg_subscription_rel.h \
+ pg_variable.h
GENERATED_HEADERS := $(CATALOG_HEADERS:%.h=%_d.h)
diff --git a/src/include/catalog/meson.build b/src/include/catalog/meson.build
index ec1cf467f6f..81398efa7c9 100644
--- a/src/include/catalog/meson.build
+++ b/src/include/catalog/meson.build
@@ -69,6 +69,7 @@ catalog_headers = [
'pg_publication_rel.h',
'pg_subscription.h',
'pg_subscription_rel.h',
+ 'pg_variable.h',
]
# The .dat files we need can just be listed alphabetically.
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index 8c7ccc69a3c..bdac0c13bec 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -97,6 +97,8 @@ extern Oid TypenameGetTypid(const char *typname);
extern Oid TypenameGetTypidExtended(const char *typname, bool temp_ok);
extern bool TypeIsVisible(Oid typid);
+extern bool VariableIsVisible(Oid varid);
+
extern FuncCandidateList FuncnameGetCandidates(List *names,
int nargs, List *argnames,
bool expand_variadic,
@@ -169,6 +171,10 @@ extern SearchPathMatcher *GetSearchPathMatcher(MemoryContext context);
extern SearchPathMatcher *CopySearchPathMatcher(SearchPathMatcher *path);
extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
+extern List *NamesFromList(List *names);
+extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
+extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
extern Oid FindDefaultConversionProc(int32 for_encoding, int32 to_encoding);
diff --git a/src/include/catalog/pg_default_acl.h b/src/include/catalog/pg_default_acl.h
index 728024b1fa7..5f94424a684 100644
--- a/src/include/catalog/pg_default_acl.h
+++ b/src/include/catalog/pg_default_acl.h
@@ -68,6 +68,7 @@ MAKE_SYSCACHE(DEFACLROLENSPOBJ, pg_default_acl_role_nsp_obj_index, 8);
#define DEFACLOBJ_FUNCTION 'f' /* function */
#define DEFACLOBJ_TYPE 'T' /* type */
#define DEFACLOBJ_NAMESPACE 'n' /* namespace */
+#define DEFACLOBJ_VARIABLE 'V' /* variable */
#endif /* EXPOSE_TO_CLIENT_CODE */
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 9e803d610d7..162cd048965 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5404,6 +5404,26 @@
prorettype => 'bool', proargtypes => 'oid oid text',
prosrc => 'has_largeobject_privilege_id_id' },
+{ oid => '9613', descr => 'user privilege on session variable by username, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name text text',
+ prosrc => 'has_session_variable_privilege_name_name' },
+{ oid => '9614', descr => 'user privilege on session variable by username, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name oid text', prosrc => 'has_session_variable_privilege_name_id' },
+{ oid => '9615', descr => 'user privilege on session variable by user oid, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text text', prosrc => 'has_session_variable_privilege_id_name' },
+{ oid => '9616', descr => 'user privilege on session variable by user oid, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid oid text', prosrc => 'has_session_variable_privilege_id_id' },
+{ oid => '9617', descr => 'current user privilege on session variable by seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'text text', prosrc => 'has_session_variable_privilege_name' },
+{ oid => '9618', descr => 'current user privilege on session variable by seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text', prosrc => 'has_session_variable_privilege_id' },
+
{ oid => '3355', descr => 'I/O',
proname => 'pg_ndistinct_in', prorettype => 'pg_ndistinct',
proargtypes => 'cstring', prosrc => 'pg_ndistinct_in' },
@@ -6604,6 +6624,9 @@
proname => 'pg_collation_is_visible', procost => '10', provolatile => 's',
prorettype => 'bool', proargtypes => 'oid',
prosrc => 'pg_collation_is_visible' },
+{ oid => '9999', descr => 'is session variable visible in search path?',
+ proname => 'pg_variable_is_visible', procost => '10', provolatile => 's',
+ prorettype => 'bool', proargtypes => 'oid', prosrc => 'pg_variable_is_visible' },
{ oid => '2854', descr => 'get OID of current session\'s temp schema, if any',
proname => 'pg_my_temp_schema', provolatile => 's', proparallel => 'r',
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
new file mode 100644
index 00000000000..3d3c6eb24b5
--- /dev/null
+++ b/src/include/catalog/pg_variable.h
@@ -0,0 +1,81 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.h
+ * definition of session variables system catalog (pg_variables)
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/catalog/pg_variable.h
+ *
+ * NOTES
+ * The Catalog.pm module reads this file and derives schema
+ * information.
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_VARIABLE_H
+#define PG_VARIABLE_H
+
+#include "catalog/genbki.h"
+#include "catalog/objectaddress.h"
+#include "catalog/pg_variable_d.h"
+#include "utils/acl.h"
+
+/* ----------------
+ * pg_variable definition. cpp turns this into
+ * typedef struct FormData_pg_variable
+ * ----------------
+ */
+CATALOG(pg_variable,9222,VariableRelationId)
+{
+ Oid oid; /* oid */
+
+ /* OID of entry in pg_type for variable's type */
+ Oid vartype BKI_LOOKUP(pg_type);
+
+ /* variable name */
+ NameData varname;
+
+ /* OID of namespace containing variable class */
+ Oid varnamespace BKI_LOOKUP(pg_namespace);
+
+ /* variable owner */
+ Oid varowner BKI_LOOKUP(pg_authid);
+
+ /* typmod for variable's type */
+ int32 vartypmod BKI_DEFAULT(-1);
+
+ /* variable collation */
+ Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation);
+
+
+#ifdef CATALOG_VARLEN /* variable-length fields start here */
+
+ /* access permissions */
+ aclitem varacl[1] BKI_DEFAULT(_null_);
+
+#endif
+} FormData_pg_variable;
+
+/* ----------------
+ * Form_pg_variable corresponds to a pointer to a tuple with
+ * the format of the pg_variable relation.
+ * ----------------
+ */
+typedef FormData_pg_variable *Form_pg_variable;
+
+DECLARE_TOAST(pg_variable, 9223, 9224);
+
+DECLARE_UNIQUE_INDEX_PKEY(pg_variable_oid_index, 9225, VariableOidIndexId, pg_variable, btree(oid oid_ops));
+DECLARE_UNIQUE_INDEX(pg_variable_varname_nsp_index, 9226, VariableNameNspIndexId, pg_variable, btree(varname name_ops, varnamespace oid_ops));
+
+extern ObjectAddress CreateVariable(ParseState *pstate,
+ CreateSessionVarStmt *stmt);
+extern void DropVariableById(Oid varid);
+
+MAKE_SYSCACHE(VARIABLENAMENSP, pg_variable_varname_nsp_index, 8);
+MAKE_SYSCACHE(VARIABLEOID, pg_variable_oid_index, 8);
+
+#endif /* PG_VARIABLE_H */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 8dd421fa0ef..b07c42f94d0 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2360,6 +2360,7 @@ typedef enum ObjectType
OBJECT_TSTEMPLATE,
OBJECT_TYPE,
OBJECT_USER_MAPPING,
+ OBJECT_VARIABLE,
OBJECT_VIEW,
} ObjectType;
@@ -3495,6 +3496,21 @@ typedef struct AlterStatsStmt
bool missing_ok; /* skip error if statistics object is missing */
} AlterStatsStmt;
+
+/* ----------------------
+ * {Create|Alter} VARIABLE Statement
+ * ----------------------
+ */
+typedef struct CreateSessionVarStmt
+{
+ NodeTag type;
+ RangeVar *variable; /* the variable to create */
+ TypeName *typeName; /* the type of variable */
+ CollateClause *collClause;
+ bool if_not_exists; /* do nothing if it already exists */
+} CreateSessionVarStmt;
+
+
/* ----------------------
* Create Function Statement
* ----------------------
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 40cf090ce61..793ace526df 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -485,6 +485,8 @@ PG_KEYWORD("validator", VALIDATOR, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("value", VALUE_P, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("values", VALUES, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("varchar", VARCHAR, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variable", VARIABLE, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variables", VARIABLES, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("variadic", VARIADIC, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("varying", VARYING, UNRESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("verbose", VERBOSE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index d250a714d59..ea86954dded 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -68,6 +68,7 @@ PG_CMDTAG(CMDTAG_ALTER_TRANSFORM, "ALTER TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TRIGGER, "ALTER TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TYPE, "ALTER TYPE", true, true, false)
PG_CMDTAG(CMDTAG_ALTER_USER_MAPPING, "ALTER USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_ALTER_VARIABLE, "ALTER VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_VIEW, "ALTER VIEW", true, false, false)
PG_CMDTAG(CMDTAG_ANALYZE, "ANALYZE", false, false, false)
PG_CMDTAG(CMDTAG_BEGIN, "BEGIN", false, false, false)
@@ -123,6 +124,7 @@ PG_CMDTAG(CMDTAG_CREATE_TRANSFORM, "CREATE TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TRIGGER, "CREATE TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TYPE, "CREATE TYPE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_USER_MAPPING, "CREATE USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_CREATE_VARIABLE, "CREATE VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_VIEW, "CREATE VIEW", true, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE, "DEALLOCATE", false, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE_ALL, "DEALLOCATE ALL", false, false, false)
@@ -175,6 +177,7 @@ PG_CMDTAG(CMDTAG_DROP_TRANSFORM, "DROP TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TRIGGER, "DROP TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TYPE, "DROP TYPE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_USER_MAPPING, "DROP USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_DROP_VARIABLE, "DROP VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_VIEW, "DROP VIEW", true, false, false)
PG_CMDTAG(CMDTAG_EXECUTE, "EXECUTE", false, false, false)
PG_CMDTAG(CMDTAG_EXPLAIN, "EXPLAIN", false, false, false)
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index 01ae5b719fd..5e1a8a82e90 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -169,6 +169,7 @@ typedef struct ArrayType Acl;
#define ACL_ALL_RIGHTS_SCHEMA (ACL_USAGE|ACL_CREATE)
#define ACL_ALL_RIGHTS_TABLESPACE (ACL_CREATE)
#define ACL_ALL_RIGHTS_TYPE (ACL_USAGE)
+#define ACL_ALL_RIGHTS_VARIABLE (ACL_SELECT|ACL_UPDATE)
/* operation codes for pg_*_aclmask */
typedef enum
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 6fab7aa6009..9503b528647 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -135,6 +135,7 @@ extern char get_func_prokind(Oid funcid);
extern bool get_func_leakproof(Oid funcid);
extern RegProcedure get_func_support(Oid funcid);
extern Oid get_relname_relid(const char *relname, Oid relnamespace);
+extern Oid get_varname_varid(const char *varname, Oid varnamespace);
extern char *get_rel_name(Oid relid);
extern Oid get_rel_namespace(Oid relid);
extern Oid get_rel_type_id(Oid relid);
@@ -207,6 +208,14 @@ extern char *get_publication_name(Oid pubid, bool missing_ok);
extern Oid get_subscription_oid(const char *subname, bool missing_ok);
extern char *get_subscription_name(Oid subid, bool missing_ok);
+extern char *get_session_variable_name(Oid varid);
+extern Oid get_session_variable_namespace(Oid varid);
+extern Oid get_session_variable_type(Oid varid);
+extern void get_session_variable_type_typmod_collid(Oid varid,
+ Oid *typid,
+ int32 *typmod,
+ Oid *collid);
+
#define type_is_array(typid) (get_element_type(typid) != InvalidOid)
/* type_is_array_domain accepts both plain arrays and domains over arrays */
#define type_is_array_domain(typid) (get_base_element_type(typid) != InvalidOid)
diff --git a/src/test/regress/expected/dependency.out b/src/test/regress/expected/dependency.out
index 75a078ada9e..cd8e4412fa9 100644
--- a/src/test/regress/expected/dependency.out
+++ b/src/test/regress/expected/dependency.out
@@ -151,3 +151,20 @@ owner of type deptest_t
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+-- should fail
+DROP DOMAIN vardomain;
+ERROR: cannot drop type vardomain because other objects depend on it
+DETAIL: column c of composite type vartype depends on type vardomain
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP TYPE vartype;
+ERROR: cannot drop type vartype because other objects depend on it
+DETAIL: session variable var1 depends on type vartype
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/expected/oidjoins.out b/src/test/regress/expected/oidjoins.out
index 215eb899be3..d9953321402 100644
--- a/src/test/regress/expected/oidjoins.out
+++ b/src/test/regress/expected/oidjoins.out
@@ -266,3 +266,7 @@ NOTICE: checking pg_subscription {subdbid} => pg_database {oid}
NOTICE: checking pg_subscription {subowner} => pg_authid {oid}
NOTICE: checking pg_subscription_rel {srsubid} => pg_subscription {oid}
NOTICE: checking pg_subscription_rel {srrelid} => pg_class {oid}
+NOTICE: checking pg_variable {vartype} => pg_type {oid}
+NOTICE: checking pg_variable {varnamespace} => pg_namespace {oid}
+NOTICE: checking pg_variable {varowner} => pg_authid {oid}
+NOTICE: checking pg_variable {varcollation} => pg_collation {oid}
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index f9db4032e1f..0c48fdfaf61 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6015,6 +6015,30 @@ COMMIT;
# final ON_ERROR_ROLLBACK: off
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | |
+(1 row)
+
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | =r/regress_variable_owner |
+(1 row)
+
+DROP VARIABLE var1;
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
-- check describing invalid multipart names
\dA regression.heap
improper qualified name (too many dotted names): regression.heap
@@ -6236,6 +6260,12 @@ cross-database references are not implemented: nonesuch.public.func_deps_stat
improper qualified name (too many dotted names): regression.myevt
\dy nonesuch.myevt
improper qualified name (too many dotted names): nonesuch.myevt
+\dV host.regression.public.var
+improper qualified name (too many dotted names): host.regression.public.var
+\dV regression|mydb.public.var
+cross-database references are not implemented: regression|mydb.public.var
+\dV nonesuch.public.var
+cross-database references are not implemented: nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
List of access methods
@@ -6470,6 +6500,12 @@ List of schemas
------+-------+-------+---------+----------+------
(0 rows)
+\dV "no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
improper qualified name (too many dotted names): "no.such.schema"."no.such.access.method"
@@ -6639,6 +6675,12 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
List of tables
@@ -6772,6 +6814,12 @@ List of text search templates
--------+------+------------+-----------+--------------+-----
(0 rows)
+\dV regression."no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -6819,6 +6867,8 @@ cross-database references are not implemented: "no.such.database"."no.such.schem
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
+cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
CREATE ROLE regress_du_role1;
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
new file mode 100644
index 00000000000..c36660ce6d3
--- /dev/null
+++ b/src/test/regress/expected/session_variables.out
@@ -0,0 +1,433 @@
+CREATE ROLE regress_variable_owner;
+SET log_statement TO ddl;
+-- should be ok
+CREATE VARIABLE var1 AS int;
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+ERROR: session variable cannot be pseudo-type anyelement
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+NOTICE: session variable "var2" does not exist, skipping
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+NOTICE: session variable "var1" already exists, skipping
+-- should fail
+CREATE VARIABLE var1 AS int;
+ERROR: session variable "var1" already exists
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TABLE t1;
+ERROR: cannot drop table t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+ERROR: cannot alter table "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TABLE t1;
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TYPE t1;
+ERROR: cannot drop type t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+ERROR: cannot alter type "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TYPE t1;
+SET log_statement TO default;
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+CREATE VARIABLE var1 AS testvar_domain;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter domain "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS testvar_type;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter type "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+NOTICE: NORMAL: orig=t normal=f istemp=f type=session variable identity=public.var1 name={public,var1} args={}
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+ obj_description
+-----------------------
+ some variable comment
+(1 row)
+
+DROP VARIABLE var1;
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+ varname | descr | type | object_names | object_args | ident
+---------------+-----------------------------------------+------------------+--------------------------+-------------+--------------------------------------------------------------------
+ svartest_var1 | session variable vartest1.svartest_var1 | session variable | {vartest1,svartest_var1} | {} | ("session variable",vartest1,svartest_var1,vartest1.svartest_var1)
+ svartest_var1 | session variable vartest2.svartest_var1 | session variable | {vartest2,svartest_var1} | {} | ("session variable",vartest2,svartest_var1,vartest2.svartest_var1)
+(2 rows)
+
+DROP SCHEMA vartest1 CASCADE;
+NOTICE: drop cascades to session variable vartest1.svartest_var1
+DROP SCHEMA vartest2 CASCADE;
+NOTICE: drop cascades to session variable vartest2.svartest_var1
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE ROLE regress_variable_reader;
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+DROP VARIABLE public.varxx;
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE public.var1 AS int;
+SET search_path TO public;
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+SET ROLE TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+--
+-- end of function has_session_variable_privilege tests.
+--
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+DROP VARIABLE public.var1;
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+DROP ROLE regress_variable_owner;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index e63ee2cf2bb..7aad3ad5d23 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -111,7 +111,7 @@ test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath sqljson
# NB: temp.sql does a reconnect which transiently uses 2 connections,
# so keep this parallel group to at most 19 tests
# ----------
-test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml
+test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml session_variables
# ----------
# Another group of parallel tests
diff --git a/src/test/regress/sql/dependency.sql b/src/test/regress/sql/dependency.sql
index 8d74ed7122c..6c18b7f840a 100644
--- a/src/test/regress/sql/dependency.sql
+++ b/src/test/regress/sql/dependency.sql
@@ -114,3 +114,17 @@ DROP USER regress_dep_user2;
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+
+-- should fail
+DROP DOMAIN vardomain;
+DROP TYPE vartype;
+
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index c58308ce14f..29d8caa7bac 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -1636,6 +1636,19 @@ COMMIT;
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+DROP VARIABLE var1;
+
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
+
-- check describing invalid multipart names
\dA regression.heap
\dA nonesuch.heap
@@ -1747,6 +1760,9 @@ DROP FUNCTION psql_error;
\dX nonesuch.public.func_deps_stat
\dy regression.myevt
\dy nonesuch.myevt
+\dV host.regression.public.var
+\dV regression|mydb.public.var
+\dV nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
@@ -1788,6 +1804,8 @@ DROP FUNCTION psql_error;
\dx "no.such.installed.extension"
\dX "no.such.extended.statistics"
\dy "no.such.event.trigger"
+\dV "no.such.variable"
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
@@ -1828,6 +1846,7 @@ DROP FUNCTION psql_error;
\dx "no.such.schema"."no.such.installed.extension"
\dX "no.such.schema"."no.such.extended.statistics"
\dy "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
@@ -1852,6 +1871,7 @@ DROP FUNCTION psql_error;
\dP regression."no.such.schema"."no.such.partitioned.relation"
\dT regression."no.such.schema"."no.such.data.type"
\dX regression."no.such.schema"."no.such.extended.statistics"
+\dV regression."no.such.schema"."no.such.variable"
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -1877,6 +1897,7 @@ DROP FUNCTION psql_error;
\dP "no.such.database"."no.such.schema"."no.such.partitioned.relation"
\dT "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
new file mode 100644
index 00000000000..eeb0f94ca3c
--- /dev/null
+++ b/src/test/regress/sql/session_variables.sql
@@ -0,0 +1,297 @@
+CREATE ROLE regress_variable_owner;
+
+SET log_statement TO ddl;
+
+-- should be ok
+CREATE VARIABLE var1 AS int;
+
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+
+-- should fail
+CREATE VARIABLE var1 AS int;
+
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TABLE t1;
+
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TABLE t1;
+
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TYPE t1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+SET log_statement TO default;
+
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+
+CREATE VARIABLE var1 AS testvar_domain;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+CREATE VARIABLE var1 AS testvar_type;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+
+DROP VARIABLE var1;
+
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+
+DROP SCHEMA vartest1 CASCADE;
+DROP SCHEMA vartest2 CASCADE;
+
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+
+CREATE ROLE regress_variable_reader;
+
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+
+DROP VARIABLE public.varxx;
+
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE public.var1 AS int;
+
+SET search_path TO public;
+
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+
+SET ROLE TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+--
+-- end of function has_session_variable_privilege tests.
+--
+
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+
+DROP VARIABLE public.var1;
+
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+
+DROP ROLE regress_variable_owner;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b6c170ac249..b2844730f79 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -540,6 +540,7 @@ CreateRoleStmt
CreateSchemaStmt
CreateSchemaStmtContext
CreateSeqStmt
+CreateSessionVarStmt
CreateStatsStmt
CreateStmt
CreateStmtContext
@@ -880,6 +881,7 @@ FormData_pg_ts_parser
FormData_pg_ts_template
FormData_pg_type
FormData_pg_user_mapping
+FormData_pg_variable
FormExtraData_pg_attribute
Form_pg_aggregate
Form_pg_am
@@ -939,6 +941,7 @@ Form_pg_ts_parser
Form_pg_ts_template
Form_pg_type
Form_pg_user_mapping
+Form_pg_variable
FormatNode
FreeBlockNumberArray
FreeListData
@@ -3102,6 +3105,7 @@ VarString
VarStringSortSupport
Variable
VariableAssignHook
+VariableInfo
VariableSetKind
VariableSetStmt
VariableShowStmt
--
2.48.1
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-02-16 09:13 ` Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Pavel Stehule @ 2025-02-16 09:13 UTC (permalink / raw)
To: jian he <[email protected]>; +Cc: Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
Hi
I removed a patch 09 - possibility to set implicit visibility of session
variables. This patch was a replacement of patch - possibility to check the
usage of variable fences.
This specific feature can be implemented in many ways, and at this moment
is useless to try to implement it.
Regards
Pavel
Attachments:
[text/x-patch] v20250216-0003-function-pg_session_variables-for-cleaning-tests.patch (4.3K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/3-v20250216-0003-function-pg_session_variables-for-cleaning-tests.patch)
download | inline diff:
From 220a061694f4761e02db390204bad551fe3980be Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 20:01:56 +0100
Subject: [PATCH 03/21] function pg_session_variables for cleaning tests
This is a function designed for testing and debugging. It returns the
content of sessionvars as-is, and can therefore display entries about
session variables that were dropped but for which this backend didn't
process the shared invalidations yet.
---
src/backend/commands/session_variable.c | 92 +++++++++++++++++++++++++
src/include/catalog/pg_proc.dat | 8 +++
2 files changed, 100 insertions(+)
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 2456a3452b9..8255f360d2e 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -527,3 +527,95 @@ ExecuteLetStmt(ParseState *pstate,
PopActiveSnapshot();
}
+
+/*
+ * pg_session_variables - designed for testing
+ *
+ * This is a function designed for testing and debugging. It returns the
+ * content of session variables as-is, and can therefore display data about
+ * session variables that were dropped, but for which this backend didn't
+ * process the shared invalidations yet.
+ */
+Datum
+pg_session_variables(PG_FUNCTION_ARGS)
+{
+#define NUM_PG_SESSION_VARIABLES_ATTS 8
+
+ InitMaterializedSRF(fcinfo, 0);
+
+ if (sessionvars)
+ {
+ ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ Datum values[NUM_PG_SESSION_VARIABLES_ATTS];
+ bool nulls[NUM_PG_SESSION_VARIABLES_ATTS];
+ HeapTuple tp;
+ bool var_is_valid = false;
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, 0, sizeof(nulls));
+
+ values[0] = ObjectIdGetDatum(svar->varid);
+ values[3] = ObjectIdGetDatum(svar->typid);
+
+ /*
+ * It is possible that the variable has been dropped from the
+ * catalog, but not yet purged from the hash table.
+ */
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ Form_pg_variable varform = (Form_pg_variable) GETSTRUCT(tp);
+
+ /*
+ * It is also possible that a variable has been dropped and
+ * someone created a new variable with the same object ID. Use
+ * the catalog information only if that is not the case.
+ */
+ if (svar->create_lsn == varform->varcreate_lsn)
+ {
+ values[1] = CStringGetTextDatum(
+ get_namespace_name(varform->varnamespace));
+
+ values[2] = CStringGetTextDatum(NameStr(varform->varname));
+ values[4] = CStringGetTextDatum(format_type_be(svar->typid));
+ values[5] = BoolGetDatum(false);
+
+ values[6] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_SELECT) == ACLCHECK_OK);
+
+ values[7] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_UPDATE) == ACLCHECK_OK);
+
+ var_is_valid = true;
+ }
+
+ ReleaseSysCache(tp);
+ }
+
+ /* if there is no matching catalog entry, return null values */
+ if (!var_is_valid)
+ {
+ nulls[1] = true;
+ nulls[2] = true;
+ nulls[4] = true;
+ values[5] = BoolGetDatum(true);
+ nulls[6] = true;
+ nulls[7] = true;
+ }
+
+ tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
+ }
+ }
+
+ return (Datum) 0;
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 162cd048965..fffc21af420 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -12487,4 +12487,12 @@
proargtypes => 'int4',
prosrc => 'gist_stratnum_common' },
+# Session variables support
+{ oid => '8488', descr => 'list of used session variables',
+ proname => 'pg_session_variables', prorows => '1000', proretset => 't',
+ provolatile => 's', proparallel => 'r', prorettype => 'record',
+ proargtypes => '', proallargtypes => '{oid,text,text,oid,text,bool,bool,bool}',
+ proargmodes => '{o,o,o,o,o,o,o,o}',
+ proargnames => '{varid,schema,name,typid,typname,removed,can_select,can_update}',
+ prosrc => 'pg_session_variables' },
]
--
2.48.1
[text/x-patch] v20250216-0004-DISCARD-VARIABLES.patch (9.6K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/4-v20250216-0004-DISCARD-VARIABLES.patch)
download | inline diff:
From 5ce565f020c732144d2b459e2627f0c17d308443 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sun, 28 Jan 2024 20:54:20 +0100
Subject: [PATCH 04/21] DISCARD VARIABLES
Implementation of DISCARD VARIABLES commands by removing hash table with session variables
and resetting related memory context.
---
doc/src/sgml/ref/discard.sgml | 13 +++-
src/backend/commands/discard.c | 6 ++
src/backend/commands/session_variable.c | 28 ++++++++-
src/backend/parser/gram.y | 6 ++
src/backend/tcop/utility.c | 3 +
src/bin/psql/tab-complete.in.c | 2 +-
src/include/commands/session_variable.h | 2 +
src/include/nodes/parsenodes.h | 1 +
src/include/tcop/cmdtaglist.h | 1 +
.../regress/expected/session_variables.out | 63 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 36 +++++++++++
11 files changed, 158 insertions(+), 3 deletions(-)
diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
index bf44c523cac..61b967f9c9b 100644
--- a/doc/src/sgml/ref/discard.sgml
+++ b/doc/src/sgml/ref/discard.sgml
@@ -21,7 +21,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
+DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES }
</synopsis>
</refsynopsisdiv>
@@ -66,6 +66,16 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>VARIABLES</literal></term>
+ <listitem>
+ <para>
+ Resets the value of all session variables. If a variable
+ is later reused, it is re-initialized to <literal>NULL</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><literal>TEMPORARY</literal> or <literal>TEMP</literal></term>
<listitem>
@@ -93,6 +103,7 @@ SELECT pg_advisory_unlock_all();
DISCARD PLANS;
DISCARD TEMP;
DISCARD SEQUENCES;
+DISCARD VARIABLES;
</programlisting></para>
</listitem>
</varlistentry>
diff --git a/src/backend/commands/discard.c b/src/backend/commands/discard.c
index 81339a75a52..5904a6c4917 100644
--- a/src/backend/commands/discard.c
+++ b/src/backend/commands/discard.c
@@ -18,6 +18,7 @@
#include "commands/async.h"
#include "commands/discard.h"
#include "commands/prepare.h"
+#include "commands/session_variable.h"
#include "commands/sequence.h"
#include "utils/guc.h"
#include "utils/portal.h"
@@ -48,6 +49,10 @@ DiscardCommand(DiscardStmt *stmt, bool isTopLevel)
ResetTempTableNamespace();
break;
+ case DISCARD_VARIABLES:
+ ResetSessionVariables();
+ break;
+
default:
elog(ERROR, "unrecognized DISCARD target: %d", stmt->target);
}
@@ -75,4 +80,5 @@ DiscardAll(bool isTopLevel)
ResetPlanCache();
ResetTempTableNamespace();
ResetSequenceCaches();
+ ResetSessionVariables();
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 8255f360d2e..a621cbe3328 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -94,7 +94,13 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
- Assert(sessionvars);
+ /*
+ * There is no guarantee of session variables being initialized, even when
+ * receiving an invalidation callback, as DISCARD [ ALL | VARIABLES ]
+ * destroys the hash table entirely.
+ */
+ if (!sessionvars)
+ return;
/*
* If the hashvalue is not specified, we have to recheck all currently
@@ -619,3 +625,23 @@ pg_session_variables(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+
+/*
+ * Fast drop of the complete content of the session variables hash table, and
+ * cleanup of any list that wouldn't be relevant anymore.
+ * This is used by the DISCARD VARIABLES (and DISCARD ALL) command.
+ */
+void
+ResetSessionVariables(void)
+{
+ /* destroy hash table and reset related memory context */
+ if (sessionvars)
+ {
+ hash_destroy(sessionvars);
+ sessionvars = NULL;
+ }
+
+ /* release memory allocated by session variables */
+ if (SVariableMemoryContext != NULL)
+ MemoryContextReset(SVariableMemoryContext);
+}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index d34ea39bc83..77d9246f4a1 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -2084,7 +2084,13 @@ DiscardStmt:
n->target = DISCARD_SEQUENCES;
$$ = (Node *) n;
}
+ | DISCARD VARIABLES
+ {
+ DiscardStmt *n = makeNode(DiscardStmt);
+ n->target = DISCARD_VARIABLES;
+ $$ = (Node *) n;
+ }
;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 7a508a3644f..6e4d2310f5c 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -2962,6 +2962,9 @@ CreateCommandTag(Node *parsetree)
case DISCARD_SEQUENCES:
tag = CMDTAG_DISCARD_SEQUENCES;
break;
+ case DISCARD_VARIABLES:
+ tag = CMDTAG_DISCARD_VARIABLES;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 57364ea6a1c..0cc8eb56bb4 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4117,7 +4117,7 @@ match_previous_words(int pattern_id,
/* DISCARD */
else if (Matches("DISCARD"))
- COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP");
+ COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP", "VARIABLES");
/* DO */
else if (Matches("DO"))
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index 2391b9ad443..a8ca43c87af 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -27,4 +27,6 @@ extern Datum GetSessionVariable(Oid varid, bool *isNull);
extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
QueryEnvironment *queryEnv, QueryCompletion *qc);
+extern void ResetSessionVariables(void);
+
#endif
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index b1e9efa6979..0270945e048 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -4036,6 +4036,7 @@ typedef enum DiscardMode
DISCARD_PLANS,
DISCARD_SEQUENCES,
DISCARD_TEMP,
+ DISCARD_VARIABLES,
} DiscardMode;
typedef struct DiscardStmt
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index 22082c30008..bef0ac25331 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -135,6 +135,7 @@ PG_CMDTAG(CMDTAG_DISCARD_ALL, "DISCARD ALL", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_PLANS, "DISCARD PLANS", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_SEQUENCES, "DISCARD SEQUENCES", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_TEMP, "DISCARD TEMP", false, false, false)
+PG_CMDTAG(CMDTAG_DISCARD_VARIABLES, "DISCARD VARIABLES", false, false, false)
PG_CMDTAG(CMDTAG_DO, "DO", false, false, false)
PG_CMDTAG(CMDTAG_DROP_ACCESS_METHOD, "DROP ACCESS METHOD", true, false, false)
PG_CMDTAG(CMDTAG_DROP_AGGREGATE, "DROP AGGREGATE", true, false, false)
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index f22467186e3..79ac40768f8 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1663,3 +1663,66 @@ DROP VARIABLE :"DBNAME".:"DBNAME".b;
DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+ var1
+-------
+ Hello
+(1 row)
+
+DISCARD ALL;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT var1;
+ var1
+------
+ AHOJ
+(1 row)
+
+DISCARD VARIABLES;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+DROP VARIABLE var1;
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS varchar;
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DISCARD VARIABLES;
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index e72360d5254..2954759aaed 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1178,3 +1178,39 @@ DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+
+DISCARD ALL;
+SELECT var1;
+
+LET var1 = 'AHOJ';
+SELECT var1;
+
+DISCARD VARIABLES;
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+
+SELECT count(*) FROM pg_session_variables();
+
+CREATE VARIABLE var1 AS varchar;
+
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+
+LET var1 = 'AHOJ';
+
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+
+DISCARD VARIABLES;
+
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
--
2.48.1
[text/x-patch] v20250216-0005-memory-cleaning-after-DROP-VARIABLE.patch (20.9K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/5-v20250216-0005-memory-cleaning-after-DROP-VARIABLE.patch)
download | inline diff:
From f49c55eaed84fc6176025683e7c934b792fce174 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 09:31:28 +0100
Subject: [PATCH 05/21] memory cleaning after DROP VARIABLE
Accepting a sinval message invalidates entries in the "sessionvars" hash table.
These entries are validated before any read or write operations on session variables.
When the entry cannot be validated, it is removed. Removal will be delayed when
the variable was dropped by the current transaction, which could still be rolled back.
---
src/backend/catalog/pg_variable.c | 7 +-
src/backend/commands/session_variable.c | 153 +++++++++++-
src/include/commands/session_variable.h | 2 +
.../isolation/expected/session-variable.out | 110 +++++++++
src/test/isolation/isolation_schedule | 1 +
.../isolation/specs/session-variable.spec | 50 ++++
.../regress/expected/session_variables.out | 217 ++++++++++++++++++
src/test/regress/sql/session_variables.sql | 120 ++++++++++
8 files changed, 655 insertions(+), 5 deletions(-)
create mode 100644 src/test/isolation/expected/session-variable.out
create mode 100644 src/test/isolation/specs/session-variable.spec
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index bb445e9434b..d672d2a9cb3 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -22,6 +22,7 @@
#include "catalog/pg_collation.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
@@ -230,7 +231,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
}
/*
- * Drop variable by OID
+ * Drop variable by OID, and register the needed session variable
+ * cleanup.
*/
void
DropVariableById(Oid varid)
@@ -250,4 +252,7 @@ DropVariableById(Oid varid)
ReleaseSysCache(tup);
table_close(rel, RowExclusiveLock);
+
+ /* do the necessary cleanup in local memory, if needed */
+ SessionVariableDropPostprocess(varid);
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index a621cbe3328..4a29ed6e0c3 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -14,6 +14,7 @@
*/
#include "postgres.h"
+#include "access/xact.h"
#include "catalog/pg_variable.h"
#include "commands/session_variable.h"
#include "executor/svariableReceiver.h"
@@ -67,6 +68,14 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ /*
+ * Top level local transaction id of the last transaction that dropped the
+ * variable, if any. We need this information to avoid freeing memory for
+ * variables dropped by the local backend, in case the operation is rolled
+ * back.
+ */
+ LocalTransactionId drop_lxid;
+
/*
* Stored value and type description can be outdated when we receive a
* sinval message. We then have to check if the stored data are still
@@ -83,6 +92,17 @@ static HTAB *sessionvars = NULL; /* hash table for session variables */
static MemoryContext SVariableMemoryContext = NULL;
+/* becomes true when we receive a sinval message */
+static bool needs_validation = false;
+
+/*
+ * The content of dropped session variables is not removed immediately. We do
+ * that in the next transaction that reads or writes a session variable.
+ * "validated_lxid" stores the transaction that performed said validation, so
+ * that we can avoid repeating the effort.
+ */
+static LocalTransactionId validated_lxid = InvalidLocalTransactionId;
+
/*
* Callback function for session variable invalidation.
*/
@@ -114,6 +134,38 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
if (hashvalue == 0 || svar->hashvalue == hashvalue)
{
svar->is_valid = false;
+ needs_validation = true;
+ }
+ }
+}
+
+/*
+ * Handle the local memory cleanup for a DROP VARIABLE command.
+ *
+ * Caller should take care of removing the pg_variable entry first.
+ */
+void
+SessionVariableDropPostprocess(Oid varid)
+{
+ Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid));
+
+ if (sessionvars)
+ {
+ bool found;
+ SVariable svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_FIND, &found);
+
+ if (found)
+ {
+ /*
+ * Save the current top level local transaction id to make sure we
+ * won't automatically remove the local variable storage in
+ * validate_all_session_variables() when the invalidation message
+ * from DROP VARIABLE arrives. After all, the transaction could
+ * still be rolled back.
+ */
+ svar->is_valid = false;
+ svar->drop_lxid = MyProc->vxid.lxid;
}
}
}
@@ -167,6 +219,67 @@ is_session_variable_valid(SVariable svar)
return result;
}
+/*
+ * Check all potentially invalid session variable data in local memory and free
+ * the memory for all invalid ones. This function is called before any read or
+ * write of a session variable. Freeing of a variable's memory is postponed if
+ * the variable has been dropped by the current transaction, since that
+ * operation could still be rolled back.
+ *
+ * It is possible that we receive a cache invalidation message while
+ * remove_invalid_session_variables() is executing, so we cannot guarantee that
+ * all entries in "sessionvars" will be set to "is_valid" after the function is
+ * done. However, we can guarantee that all entries get checked once.
+ */
+static void
+remove_invalid_session_variables(void)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ /*
+ * The validation requires system catalog access, so the session state
+ * should be "in transaction".
+ */
+ Assert(IsTransactionState());
+
+ if (!needs_validation || !sessionvars)
+ return;
+
+ /*
+ * Reset the flag before we start the validation. It can be set again
+ * by concurrently incoming sinval messages.
+ */
+ needs_validation = false;
+
+ elog(DEBUG1, "effective call of validate_all_session_variables()");
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (!svar->is_valid)
+ {
+ if (svar->drop_lxid == MyProc->vxid.lxid)
+ {
+ /* try again in the next transaction */
+ needs_validation = true;
+ continue;
+ }
+
+ if (!is_session_variable_valid(svar))
+ {
+ Oid varid = svar->varid;
+
+ free_session_variable_value(svar);
+ hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ else
+ svar->is_valid = true;
+ }
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
@@ -196,6 +309,8 @@ setup_session_variable(SVariable svar, Oid varid)
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+ svar->drop_lxid = InvalidTransactionId;
+
svar->isnull = true;
svar->value = (Datum) 0;
@@ -319,22 +434,42 @@ get_session_variable(Oid varid)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
if (found)
{
+ /*
+ * The session variable could have been dropped by a DROP VARIABLE
+ * statement in a subtransaction that was later rolled back, which
+ * means that we may have to work with the data of a variable marked
+ * as invalid.
+ */
if (!svar->is_valid)
{
/*
- * If there was an invalidation message, the variable might still be
- * valid, but we have to check with the system catalog.
+ * We have to check the system catalog to see if the variable is
+ * still valid, even if an invalidation message set it to invalid.
+ *
+ * The variable must be validated before it is accessed. The oid
+ * should be valid, because the related session variable is already
+ * locked, and remove_invalid_session_variables() would remove
+ * variables dropped by other transactions.
*/
if (is_session_variable_valid(svar))
svar->is_valid = true;
else
- /* if the value cannot be validated, we have to discard it */
- free_session_variable_value(svar);
+ elog(ERROR, "unexpected state of session variable %u", varid);
}
}
else
@@ -395,6 +530,16 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index a8ca43c87af..d3cc79b5608 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -21,6 +21,8 @@
#include "tcop/cmdtag.h"
#include "utils/queryenvironment.h"
+extern void SessionVariableDropPostprocess(Oid varid);
+
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
new file mode 100644
index 00000000000..0a5579dc7ce
--- /dev/null
+++ b/src/test/isolation/expected/session-variable.out
@@ -0,0 +1,110 @@
+Parsed test spec with 4 sessions
+
+starting permutation: let val drop val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+
+starting permutation: let val s1 drop val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+step sr1: ROLLBACK;
+
+starting permutation: let val dbg drop create dbg val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name|removed
+------+----+-------
+ | |t
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+
+starting permutation: let val s1 dbg drop create dbg val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+step sr1: ROLLBACK;
+
+starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+step create3: CREATE VARIABLE myvar3 AS text;
+step let3: LET myvar3 = 'test';
+step s3: BEGIN;
+step create4: CREATE VARIABLE myvar4 AS text;
+step let4: LET myvar4 = 'test';
+step drop4: DROP VARIABLE myvar4;
+step drop3: DROP VARIABLE myvar3;
+step inval3: SELECT COUNT(*) >= 0 FROM pg_foreign_table;
+?column?
+--------
+t
+(1 row)
+
+step discard: DISCARD VARIABLES;
+step sc3: COMMIT;
+step state: SELECT varname FROM pg_variable;
+varname
+-------
+myvar
+(1 row)
+
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 143109aa4da..7453685d046 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -115,3 +115,4 @@ test: serializable-parallel-2
test: serializable-parallel-3
test: matview-write-skew
test: lock-nowait
+test: session-variable
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
new file mode 100644
index 00000000000..c864fee4006
--- /dev/null
+++ b/src/test/isolation/specs/session-variable.spec
@@ -0,0 +1,50 @@
+# Test session variables memory cleanup for sinval
+
+setup
+{
+ CREATE VARIABLE myvar AS text;
+}
+
+teardown
+{
+ DROP VARIABLE IF EXISTS myvar;
+}
+
+session s1
+step s1 { BEGIN; }
+step let { LET myvar = 'test'; }
+step val { SELECT myvar; }
+step dbg { SELECT schema, name, removed FROM pg_session_variables(); }
+step sr1 { ROLLBACK; }
+
+session s2
+step drop { DROP VARIABLE myvar; }
+step create { CREATE VARIABLE myvar AS text; }
+
+session s3
+step s3 { BEGIN; }
+step let3 { LET myvar3 = 'test'; }
+step create4 { CREATE VARIABLE myvar4 AS text; }
+step let4 { LET myvar4 = 'test'; }
+step drop4 { DROP VARIABLE myvar4; }
+step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; }
+step discard { DISCARD VARIABLES; }
+step sc3 { COMMIT; }
+step state { SELECT varname FROM pg_variable; }
+
+session s4
+step create3 { CREATE VARIABLE myvar3 AS text; }
+step drop3 { DROP VARIABLE myvar3; }
+
+# Concurrent drop of a known variable should lead to an error
+permutation let val drop val
+# Same, but with an explicit transaction
+permutation let val s1 drop val sr1
+# Concurrent drop/create of a known variable should lead to empty variable
+permutation let val dbg drop create dbg val
+# Concurrent drop/create of a known variable should lead to empty variable
+# We need a transaction to make sure that we won't accept invalidation when
+# calling the dbg step after the concurrent drop
+permutation let val s1 dbg drop create dbg val sr1
+# test for DISCARD ALL when all internal queues have actions registered
+permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 79ac40768f8..2783caa8446 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1726,3 +1726,220 @@ SELECT count(*) FROM pg_session_variables();
0
(1 row)
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+-- should fail
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1, var2;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 2954759aaed..a624ab8b67f 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1214,3 +1214,123 @@ DISCARD VARIABLES;
-- should be zero again
SELECT count(*) FROM pg_session_variables();
+
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+
+-- should fail
+SELECT var1;
+
+ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ROLLBACK;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+DROP VARIABLE var1, var2;
--
2.48.1
[text/x-patch] v20250216-0006-plpgsql-tests.patch (16.9K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/6-v20250216-0006-plpgsql-tests.patch)
download | inline diff:
From adb65ee0b20147b5fe05d2e38909d93a2dbf4cf0 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 14:06:06 +0100
Subject: [PATCH 06/21] plpgsql tests
---
src/pl/plpgsql/src/Makefile | 3 +-
.../src/expected/plpgsql_session_variable.out | 382 ++++++++++++++++++
src/pl/plpgsql/src/meson.build | 1 +
.../src/sql/plpgsql_session_variable.sql | 289 +++++++++++++
4 files changed, 674 insertions(+), 1 deletion(-)
create mode 100644 src/pl/plpgsql/src/expected/plpgsql_session_variable.out
create mode 100644 src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile
index 63cb96fae3e..bbcae27d422 100644
--- a/src/pl/plpgsql/src/Makefile
+++ b/src/pl/plpgsql/src/Makefile
@@ -35,7 +35,8 @@ REGRESS_OPTS = --dbname=$(PL_TESTDB)
REGRESS = plpgsql_array plpgsql_cache plpgsql_call plpgsql_control \
plpgsql_copy plpgsql_domain plpgsql_misc \
plpgsql_record plpgsql_simple plpgsql_transaction \
- plpgsql_trap plpgsql_trigger plpgsql_varprops
+ plpgsql_trap plpgsql_trigger plpgsql_varprops \
+ plpgsql_session_variable
# where to find gen_keywordlist.pl and subsidiary files
TOOLSDIR = $(top_srcdir)/src/tools
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
new file mode 100644
index 00000000000..ab779900596
--- /dev/null
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -0,0 +1,382 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+LET plpgsql_sv_var = pi();
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+NOTICE: value of session variable is 3.14159265358979
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+ pi_multiply_2
+------------------
+ 6.28318530717959
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var;
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+END;
+-- execute outside of a transaction
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP FUNCTION test_func();
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+SET ROLE TO regress_var_owner_role;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_reader_role;
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail
+SELECT var_read_func();
+ERROR: permission denied for session variable plpgsql_sv_var1
+CONTEXT: PL/pgSQL expression "plpgsql_sv_var1"
+PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should be ok
+SELECT var_read_func();
+NOTICE: 10
+ var_read_func
+---------------
+
+(1 row)
+
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+DROP VARIABLE plpgsql_sv_var1;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail, but not crash
+SELECT var_read_func();
+ERROR: column "plpgsql_sv_var1" does not exist
+LINE 1: plpgsql_sv_var1
+ ^
+QUERY: plpgsql_sv_var1
+CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+DROP FUNCTION var_read_func;
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+ inc_var_int
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+LET plpgsql_sv_var2 = 0.0;
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+ inc_var_num
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+NOTICE: variable is 1000
+DROP VARIABLE plpgsql_sv_var1;
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+select ffunc();
+ ffunc
+-------
+ abc
+(1 row)
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+DROP VARIABLE plpgsql_sv_v;
diff --git a/src/pl/plpgsql/src/meson.build b/src/pl/plpgsql/src/meson.build
index 33c49ac25d9..1d01d1c2629 100644
--- a/src/pl/plpgsql/src/meson.build
+++ b/src/pl/plpgsql/src/meson.build
@@ -88,6 +88,7 @@ tests += {
'plpgsql_trap',
'plpgsql_trigger',
'plpgsql_varprops',
+ 'plpgsql_session_variable',
],
},
}
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
new file mode 100644
index 00000000000..a3cc264cf38
--- /dev/null
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -0,0 +1,289 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+
+LET plpgsql_sv_var = pi();
+
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+
+DROP VARIABLE plpgsql_sv_var;
+
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+END;
+
+-- execute outside of a transaction
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+SELECT test_func();
+
+DROP FUNCTION test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+SET ROLE TO regress_var_owner_role;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_reader_role;
+
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should be ok
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail, but not crash
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+DROP FUNCTION var_read_func;
+
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+
+LET plpgsql_sv_var2 = 0.0;
+
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+
+select ffunc();
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+
+DROP VARIABLE plpgsql_sv_v;
--
2.48.1
[text/x-patch] v20250216-0007-GUC-session_variables_ambiguity_warning.patch (15.1K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/7-v20250216-0007-GUC-session_variables_ambiguity_warning.patch)
download | inline diff:
From e5553d6ad38307f7b25cda2491c317779f77b368 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 21 May 2024 17:55:24 +0200
Subject: [PATCH 07/21] GUC session_variables_ambiguity_warning
Inside an query the session variables can be shadowed. This behaviour is by design,
because this ensuring so new variables doesn't break existing queries. But this
behaviour can be confusing, because shadowing is quiet.
When new GUC session_variables_ambiguity_warning is on, then the warning
is displayed, when some session variable can be used, but it is not used
due shadowing. This feature should to help with investigation of unexpected
behaviour.
Note: PLpgSQL has an option that controls priority of identifier's spaces
(SQL or PLpgSQL). Default behaviour doesn't allows collisions. I believe
this default is the best. I cannot to implement similar very strict
behaviour to session variables, because one unhappy named session variable
can breaks an applications. The problems related to badly named PLpgSQL's
varible is limitted just to only one routine.
---
doc/src/sgml/config.sgml | 60 +++++++++++++++++++
doc/src/sgml/ddl.sgml | 11 ++++
src/backend/parser/parse_expr.c | 49 +++++++++++++--
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/parser/parse_expr.h | 1 +
.../src/expected/plpgsql_session_variable.out | 33 ++++++++++
.../src/sql/plpgsql_session_variable.sql | 29 +++++++++
.../regress/expected/session_variables.out | 26 ++++++++
src/test/regress/sql/session_variables.sql | 26 ++++++++
10 files changed, 241 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 60829b79d83..97f623f0498 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -10940,6 +10940,66 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-ambiguity-warning" xreflabel="session_variables_ambiguity_warning">
+ <term><varname>session_variables_ambiguity_warning</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_ambiguity_warning</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when any identifier in a query could be
+ used as both a column identifier, routine variable or a session
+ variable identifier. The default is <literal>off</literal>.
+ </para>
+ <para>
+ Session variables can be shadowed by column references in a query, this
+ is an expected behavior. Previously working queries shouldn't error out
+ by creating any session variable, so session variables are always shadowed
+ if an identifier is ambiguous. Variables should be referenced using
+ anunambiguous identifier without any possibility for a collision with
+ identifier of other database objects (column names or record fields names).
+ The warning messages emitted when enabling <varname>session_variables_ambiguity_warning</varname>
+ can help finding such identifier collision.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE a int;
+LET a = 100;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+ a
+----
+ 10
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_ambiguity_warning TO on;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a FROM foo;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a
+----
+ 10
+(1 row)
+</screen>
+ </para>
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. For testing or development environments it's recommended to
+ enable it if you use session variables.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 5e671d5be4d..96912aaa436 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5445,6 +5445,17 @@ SELECT name FROM foo;
Alice
</programlisting>
</para>
+
+ <para>
+ When a query contains identifiers or qualified identifiers that could be
+ used as both a session variable identifiers and as column identifier,
+ then the column identifier is preferred every time. Warnings can be
+ emitted when this situation happens by enabling configuration parameter <xref
+ linkend="guc-session-variables-ambiguity-warning"/>. User can explicitly
+ qualify the source object by syntax <literal>table.column</literal> or
+ <literal>schema.variable</literal>. It is strongly recommended to rename
+ shadowed variables or use qualified names always.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 4f208c7efdd..63f1732f69e 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -45,6 +45,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
+bool session_variables_ambiguity_warning = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -960,11 +961,51 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
*
* SELECT foo.a, foo.b, foo.c FROM foo;
*
- * However, that is very confusing, so we disallow it. We don't try to
- * identify a variable if we know that it would be shadowed.
- * -----
+ * However, that is very confusing, so we disallow it.
+ *
+ * When session_variables_ambiguity_warning is requested, then we
+ * need to identify a variable although we know, so this variable
+ * would be shadowed.
*/
- if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ if (node || (relname && crerr == CRERR_NO_COLUMN))
+ {
+ /*
+ * In this path we just try (if it is wanted) detect if session
+ * variable is shadowed.
+ */
+ if (session_variables_ambiguity_warning)
+ {
+ /*
+ * The AccessShareLock is created on related session variable.
+ * The lock will be kept for the whole transaction.
+ */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, true);
+
+ if (OidIsValid(varid))
+ {
+ /* this path will ending by WARNING. Unlock variable first */
+ UnlockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (node)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is shadowed",
+ NameListToString(cref->fields)),
+ errdetail("Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name."),
+ parser_errposition(pstate, cref->location)));
+ else
+ /* session variable is shadowed by RTE */
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s.%s\" is shadowed",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ errdetail("Session variables can be shadowed by tables or table's aliases with the same name."),
+ parser_errposition(pstate, cref->location)));
+ }
+ }
+ }
+ else
{
/* takes an AccessShareLock on the session variable */
varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 42728189322..491fb06415b 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1616,6 +1616,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_ambiguity_warning", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when reference to a session variable is ambiguous."),
+ NULL
+ },
+ &session_variables_ambiguity_warning,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index d472987ed46..8e17eaca0dd 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -735,6 +735,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_read_only = off
#default_transaction_deferrable = off
#session_replication_role = 'origin'
+#session_variables_ambiguity_warning = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index efbaff8e710..d2209070181 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -17,6 +17,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
+extern PGDLLIMPORT bool session_variables_ambiguity_warning;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index ab779900596..a6523f7afe2 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -354,6 +354,39 @@ $$;
NOTICE: session variable is 100
NOTICE: plpgsql variable is 1000
NOTICE: variable is 1000
+-- againt with session_variables_ambiguity_warning(on)
+SET session_variables_ambiguity_warning TO on;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+WARNING: session variable "plpgsql_sv_var1" is shadowed
+LINE 1: plpgsql_sv_var1
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+QUERY: plpgsql_sv_var1
+NOTICE: variable is 1000
+SET session_variables_ambiguity_warning TO off;
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
CREATE VARIABLE plpgsql_sv_v text;
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
index a3cc264cf38..9b8e90e81fa 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -260,6 +260,35 @@ BEGIN
END;
$$;
+-- againt with session_variables_ambiguity_warning(on)
+
+SET session_variables_ambiguity_warning TO on;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+SET session_variables_ambiguity_warning TO off;
+
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 2783caa8446..7c350ad5ef9 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1524,6 +1524,9 @@ CREATE TABLE vartest_foo(a int, b int);
INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
-- should to fail
SELECT var1.* FROM vartest_foo;
ERROR: missing FROM-clause entry for table "var1"
@@ -1549,6 +1552,7 @@ SELECT count(var1.*) FROM vartest_foo var1;
2
(1 row)
+SET session_variables_ambiguity_warning TO off;
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
NOTICE: drop cascades to 2 other objects
@@ -1943,3 +1947,25 @@ SELECT var1;
(1 row)
DROP VARIABLE var1, var2;
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+CREATE VARIABLE xxtab.avar int;
+CREATE TABLE public.xxtab(avar int);
+INSERT INTO public.xxtab VALUES(1);
+LET xxtab.avar = 20;
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+WARNING: session variable "xxtab.avar" is shadowed
+LINE 1: SELECT xxtab.avar FROM public.xxtab;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ avar
+------
+ 1
+(1 row)
+
+SET session_variables_ambiguity_warning TO off;
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
+NOTICE: drop cascades to session variable xxtab.avar
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index a624ab8b67f..68be415bf26 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1079,6 +1079,10 @@ INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
+
-- should to fail
SELECT var1.* FROM vartest_foo;
@@ -1091,6 +1095,8 @@ SELECT count(var1.*) FROM vartest_foo;
-- should be ok
SELECT count(var1.*) FROM vartest_foo var1;
+SET session_variables_ambiguity_warning TO off;
+
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
@@ -1334,3 +1340,23 @@ BEGIN; DROP VARIABLE var1; ROLLBACK;
SELECT var1;
DROP VARIABLE var1, var2;
+
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+
+CREATE VARIABLE xxtab.avar int;
+
+CREATE TABLE public.xxtab(avar int);
+
+INSERT INTO public.xxtab VALUES(1);
+
+LET xxtab.avar = 20;
+
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+
+SET session_variables_ambiguity_warning TO off;
+
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
--
2.48.1
[text/x-patch] v20250216-0002-Storage-for-session-variables-and-SQL-interface.patch (159.6K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/8-v20250216-0002-Storage-for-session-variables-and-SQL-interface.patch)
download | inline diff:
From 492fffd90740e4b1c9d80bbefdf04c6e88908e90 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Thu, 6 Jul 2023 08:29:21 +0200
Subject: [PATCH 02/21] Storage for session variables and SQL interface
Session variables are stored in session memory in a dedicated hash table.
They are set by the LET command and read by the SELECT command.
The access rights should be checked.
The identifiers of session variables should always be shadowed by possible
column identifiers: we don't want to break an application by creating some
badly named session variable.
The limits of this patch (solved by other patches):
- session variables block parallel execution
- session variables blocks simple expression evaluation (in plpgsql)
- SQL functions with session variables are not inlined
- CALL statement is not supported (usage of direct access to express executor)
- EXECUTE statement is not supported (usage of direct access to express executor)
- memory used by dropped session variables is not released
Implementations of EXPLAIN LET and PREPARE LET statements
are in separate patches (for better readability)
---
doc/src/sgml/catalogs.sgml | 13 +
doc/src/sgml/ddl.sgml | 61 +
doc/src/sgml/func.sgml | 4 +-
doc/src/sgml/glossary.sgml | 5 +-
doc/src/sgml/parallel.sgml | 6 +
doc/src/sgml/plpgsql.sgml | 14 +
doc/src/sgml/ref/allfiles.sgml | 1 +
doc/src/sgml/ref/alter_variable.sgml | 1 +
doc/src/sgml/ref/create_variable.sgml | 5 +-
doc/src/sgml/ref/drop_variable.sgml | 1 +
doc/src/sgml/ref/let.sgml | 96 ++
doc/src/sgml/reference.sgml | 1 +
src/backend/catalog/dependency.c | 5 +
src/backend/catalog/namespace.c | 289 ++++
src/backend/catalog/pg_variable.c | 2 +
src/backend/commands/Makefile | 1 +
src/backend/commands/meson.build | 1 +
src/backend/commands/prepare.c | 10 +
src/backend/commands/session_variable.c | 529 +++++++
src/backend/executor/Makefile | 1 +
src/backend/executor/execExpr.c | 32 +
src/backend/executor/execMain.c | 66 +
src/backend/executor/meson.build | 1 +
src/backend/executor/svariableReceiver.c | 172 +++
src/backend/nodes/nodeFuncs.c | 10 +
src/backend/optimizer/plan/planner.c | 36 +
src/backend/optimizer/plan/setrefs.c | 156 ++-
src/backend/optimizer/prep/prepjointree.c | 3 +
src/backend/optimizer/util/clauses.c | 33 +-
src/backend/parser/analyze.c | 272 +++-
src/backend/parser/gram.y | 39 +-
src/backend/parser/parse_agg.c | 9 +
src/backend/parser/parse_expr.c | 223 ++-
src/backend/parser/parse_func.c | 2 +
src/backend/parser/parse_merge.c | 1 +
src/backend/tcop/dest.c | 7 +
src/backend/tcop/utility.c | 16 +
src/backend/utils/adt/ruleutils.c | 46 +
src/backend/utils/cache/plancache.c | 41 +-
src/backend/utils/fmgr/fmgr.c | 10 +-
src/bin/psql/tab-complete.in.c | 12 +-
src/include/catalog/namespace.h | 1 +
src/include/catalog/pg_variable.h | 9 +
src/include/commands/session_variable.h | 30 +
src/include/executor/svariableReceiver.h | 22 +
src/include/nodes/execnodes.h | 14 +
src/include/nodes/parsenodes.h | 17 +
src/include/nodes/pathnodes.h | 14 +
src/include/nodes/plannodes.h | 9 +
src/include/nodes/primnodes.h | 14 +
src/include/optimizer/planmain.h | 2 +
src/include/parser/kwlist.h | 1 +
src/include/parser/parse_node.h | 3 +
src/include/tcop/cmdtaglist.h | 1 +
src/include/tcop/dest.h | 1 +
src/pl/plpgsql/src/pl_exec.c | 3 +-
.../regress/expected/session_variables.out | 1232 +++++++++++++++++
src/test/regress/sql/session_variables.sql | 883 ++++++++++++
src/tools/pgindent/typedefs.list | 5 +
59 files changed, 4467 insertions(+), 27 deletions(-)
create mode 100644 doc/src/sgml/ref/let.sgml
create mode 100644 src/backend/commands/session_variable.c
create mode 100644 src/backend/executor/svariableReceiver.c
create mode 100644 src/include/commands/session_variable.h
create mode 100644 src/include/executor/svariableReceiver.h
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 7ba91b1f4b1..4f502274bfa 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9810,6 +9810,19 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcreate_lsn</structfield> <type>pg_lsn</type>
+ </para>
+ <para>
+ LSN of the transaction where the variable was created.
+ <structfield>varcreate_lsn</structfield> and
+ <structfield>oid</structfield> together form the all-time unique
+ identifier (<structfield>oid</structfield> alone is not enough, since
+ object identifiers can get reused).
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>varname</structfield> <type>name</type>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index edfb7db24fc..5e671d5be4d 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5384,6 +5384,67 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
The session variable holds value in session memory. This value is private
to each session and is released when the session ends.
</para>
+
+ <para>
+ The value of a session variable is set with the SQL statement
+ <command>LET</command>. The value of a session variable can be retrieved
+ with the SQL statement <command>SELECT</command>.
+<programlisting>
+CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
+</programlisting>
+
+ or
+
+<programlisting>
+CREATE VARIABLE public.current_user_id AS integer;
+GRANT SELECT ON VARIABLE public.current_user_id TO PUBLIC;
+LET current_user_id = (SELECT id FROM users WHERE usename = session_user);
+SELECT current_user_id;
+</programlisting>
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a variable's value returns a <literal>NULL</literal>, unless its value has
+ been set to something else in the current session using the
+ <command>LET</command> command. Session variables are not transactional:
+ any changes made to the value of a session variable in a transaction won't
+ be undone if the transaction is rolled back (just like variables in
+ procedural languages). Session variables themselves are persistent, but
+ their values are neither persistent nor shared (like the content of
+ temporary tables).
+ </para>
+
+ <para>
+ Inside a query or an expression, a session variable can be
+ <quote>shadowed</quote> by a column with the same name. Similarly, the
+ name of a function or procedure argument or a PL/pgSQL variable (see
+ <xref linkend="plpgsql-declarations"/>) can shadow a session variable
+ in the routine's body. Such collisions of identifiers can be resolved
+ by using qualified identifiers: Session variables can be qualified with
+ the schema name, columns can use table aliases, routine variables can use
+ block labels, and routine arguments can use the routine name.
+<programlisting>
+CREATE VARIABLE name AS text;
+LET name = 'John';
+
+CREATE TABLE foo(name text);
+INSERT INTO foo VALUES('Alice');
+
+-- variable name is shadowed
+SELECT name FROM foo;
+</programlisting>
+
+ which returns:
+
+<programlisting>
+ name
+-------
+ Alice
+</programlisting>
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 4a484034c0f..0cacd92e165 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25595,8 +25595,8 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
't' for <literal>TABLESPACE</literal>,
'F' for <literal>FOREIGN DATA WRAPPER</literal>,
'S' for <literal>FOREIGN SERVER</literal>,
- or
- 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal>.
+ 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal> or
+ 'V' for <literal>SESSION VARIABLE</literal>.
</para></entry>
</row>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index b921f5a3339..81988f2dfea 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1675,8 +1675,9 @@
<para>
A persistent database object that holds a value in session memory. This
value is private to each session and is released when the session ends.
- Read or write access to session variables is controlled by privileges,
- similar to other database objects.
+ The default value of the session variable is null. Read or write access
+ to session variables is controlled by privileges, similar to other database
+ objects.
</para>
<para>
For more information, see <xref linkend="ddl-session-variables"/>.
diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index 1ce9abf86f5..683dede6adc 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -515,6 +515,12 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
Plan nodes that reference a correlated <literal>SubPlan</literal>.
</para>
</listitem>
+
+ <listitem>
+ <para>
+ Plan nodes that use a session variable.
+ </para>
+ </listitem>
</itemizedlist>
<sect2 id="parallel-labeling">
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index 78e4983139b..bfbff9ab74e 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -6034,6 +6034,20 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE;
</programlisting>
</para>
</sect3>
+
+ <sect3 id="plpgsql-porting-package-variables">
+ <title><command>Packages and package variables</command></title>
+
+ <para>
+ The <application>PL/pgSQL</application> language has no packages, and
+ therefore no package variables or package constants.
+ You can consider translating an Oracle package into a schema in
+ <productname>PostgreSQL</productname>. Package functions and procedures
+ would then become functions and procedures in that schema, and package
+ variables could be translated to session variables in that schema.
+ (see <xref linkend="ddl-session-variables"/>).
+ </para>
+ </sect3>
</sect2>
<sect2 id="plpgsql-porting-appendix">
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index 2f67de3e21b..cc3bd5ab540 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -158,6 +158,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY grant SYSTEM "grant.sgml">
<!ENTITY importForeignSchema SYSTEM "import_foreign_schema.sgml">
<!ENTITY insert SYSTEM "insert.sgml">
+<!ENTITY let SYSTEM "let.sgml">
<!ENTITY listen SYSTEM "listen.sgml">
<!ENTITY load SYSTEM "load.sgml">
<!ENTITY lock SYSTEM "lock.sgml">
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
index 96d2586423e..221a699469b 100644
--- a/doc/src/sgml/ref/alter_variable.sgml
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -173,6 +173,7 @@ ALTER VARIABLE boo SET SCHEMA private;
<simplelist type="inline">
<member><xref linkend="sql-createvariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
</refentry>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index 6e988f2e472..cd9ff63975a 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -120,9 +120,11 @@ CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceab
<title>Examples</title>
<para>
- Create an date session variable <literal>var1</literal>:
+ Create a session variable <literal>var1</literal> of data type date:
<programlisting>
CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
</programlisting>
</para>
@@ -143,6 +145,7 @@ CREATE VARIABLE var1 AS date;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
index 5bdb3560f0b..67988b5fcd8 100644
--- a/doc/src/sgml/ref/drop_variable.sgml
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -111,6 +111,7 @@ DROP VARIABLE var1;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/let.sgml b/doc/src/sgml/ref/let.sgml
new file mode 100644
index 00000000000..00f9bea91fe
--- /dev/null
+++ b/doc/src/sgml/ref/let.sgml
@@ -0,0 +1,96 @@
+<!--
+doc/src/sgml/ref/let.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-let">
+ <indexterm zone="sql-let">
+ <primary>LET</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>changing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>LET</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>LET</refname>
+ <refpurpose>change a session variable's value</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+LET <replaceable class="parameter">session_variable</replaceable> = <replaceable class="parameter">sql_expression</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>LET</command> command assigns a value to the specified session
+ variable.
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">session_variable</replaceable></term>
+ <listitem>
+ <para>
+ The name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">sql_expression</replaceable></term>
+ <listitem>
+ <para>
+ An arbitrary SQL expression. The result must be of a data type that can
+ be cast to the type of the session variable in an assignment.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+<programlisting>
+CREATE VARIABLE myvar AS integer;
+LET myvar = 10;
+LET myvar = (SELECT sum(val) FROM tab);
+</programlisting>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>LET</command> is a <productname>PostgreSQL</productname>
+ extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index 25578f3946c..13e4adc5df3 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -186,6 +186,7 @@
&grant;
&importForeignSchema;
&insert;
+ &let;
&listen;
&load;
&lock;
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 9e0f648b74f..90c9e8bb254 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1864,6 +1864,11 @@ find_expr_references_walker(Node *node,
{
Param *param = (Param *) node;
+ /* a variable parameter depends on the session variable */
+ if (param->paramkind == PARAM_VARIABLE)
+ add_object_address(VariableRelationId, param->paramvarid, 0,
+ context->addrs);
+
/* A parameter must depend on the parameter's datatype */
add_object_address(TypeRelationId, param->paramtype, 0,
context->addrs);
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 4307cad15c7..beafee2a341 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -3497,6 +3497,295 @@ NamesFromList(List *names)
return result;
}
+/* -----
+ * IdentifyVariable - try to find a variable from a list of identifiers
+ *
+ * Returns the OID of the variable found, or InvalidOid.
+ *
+ * "names" is a list of up to four identifiers; possible meanings are:
+ * - variable (searched on the search_path)
+ * - schema.variable
+ * - variable.attribute (searched on the search_path)
+ * - schema.variable.attribute
+ * - database.schema.variable
+ * - database.schema.variable.attribute
+ *
+ * If there is more than one way to identify a variable, "not_unique" will be
+ * set to true.
+ *
+ * Unless "noerror" is true, an error is raised if there are more than four
+ * identifiers in the list, or if the named database is not the current one.
+ * This is useful if we want to identify a shadowed variable.
+ *
+ * If an attribute is identified, it is stored in "attrname", otherwise the
+ * parameter is set to NULL.
+ *
+ * The identified session variable will be locked with an AccessShareLock.
+ * -----
+ */
+Oid
+IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror)
+{
+ Oid varid = InvalidOid;
+ Oid old_varid = InvalidOid;
+ uint64 inval_count;
+ bool retry = false;
+
+ /*
+ * DDL operations can change the results of a name lookup. Since all such
+ * operations will generate invalidation messages, we keep track of
+ * whether any such messages show up while we're performing the operation,
+ * and retry until either (1) no more invalidation messages show up or (2)
+ * the answer doesn't change.
+ */
+ for (;;)
+ {
+ Node *field1 = NULL;
+ Node *field2 = NULL;
+ Node *field3 = NULL;
+ Node *field4 = NULL;
+ char *a = NULL;
+ char *b = NULL;
+ char *c = NULL;
+ char *d = NULL;
+ Oid varoid_without_attr = InvalidOid;
+ Oid varoid_with_attr = InvalidOid;
+
+ *not_unique = false;
+ *attrname = NULL;
+ varid = InvalidOid;
+
+ inval_count = SharedInvalidMessageCounter;
+
+ switch (list_length(names))
+ {
+ case 1:
+ field1 = linitial(names);
+
+ Assert(IsA(field1, String));
+
+ varid = LookupVariable(NULL, strVal(field1), true);
+ break;
+
+ case 2:
+ field1 = linitial(names);
+ field2 = lsecond(names);
+
+ Assert(IsA(field1, String));
+ a = strVal(field1);
+
+ if (IsA(field2, String))
+ {
+ /* when both fields are of string type */
+ b = strVal(field2);
+
+ /*
+ * a.b can mean "schema"."variable" or
+ * "variable"."attribute". Check both variants, and
+ * returns InvalidOid with not_unique flag, when both
+ * interpretations are possible.
+ */
+ varoid_without_attr = LookupVariable(a, b, true);
+ varoid_with_attr = LookupVariable(NULL, a, true);
+ }
+ else
+ {
+ /* the last field of list can be star too */
+ Assert(IsA(field2, A_Star));
+
+ /*
+ * The syntax ident.* is used only by relation aliases,
+ * and then this identifier cannot be a reference to
+ * session variable.
+ */
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = b;
+ varid = varoid_with_attr;
+ }
+ break;
+
+ case 3:
+ {
+ bool field1_is_catalog = false;
+
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+
+ if (IsA(field3, String))
+ {
+ c = strVal(field3);
+
+ /*
+ * a.b.c can mean catalog.schema.variable or
+ * schema.variable.attribute.
+ *
+ * Check both variants, and set not_unique flag, when
+ * both interpretations are possible.
+ *
+ * When third node is star, only possible
+ * interpretation is schema.variable.*, but this
+ * pattern is not supported now.
+ */
+ varoid_with_attr = LookupVariable(a, b, true);
+
+ /*
+ * check pattern catalog.schema.variable only when
+ * there is possibility to success.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) == 0)
+ {
+ field1_is_catalog = true;
+ varoid_without_attr = LookupVariable(b, c, true);
+ }
+ }
+ else
+ {
+ Assert(IsA(field3, A_Star));
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = c;
+ varid = varoid_with_attr;
+ }
+
+ /*
+ * When we didn't find variable, we can (when it is
+ * allowed) raise cross-database reference error.
+ */
+ if (!OidIsValid(varid) && !noerror && !field1_is_catalog)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+ break;
+
+ case 4:
+ {
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+ field4 = lfourth(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+ Assert(IsA(field3, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+ c = strVal(field3);
+
+ /*
+ * In this case, "a" is used as catalog name - check it.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) != 0)
+ {
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+
+ if (IsA(field4, String))
+ {
+ d = strVal(field4);
+ }
+ else
+ {
+ Assert(IsA(field4, A_Star));
+ return InvalidOid;
+ }
+
+ *attrname = d;
+ varid = LookupVariable(b, c, true);
+ }
+ break;
+
+ default:
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper qualified name (too many dotted names): %s",
+ NameListToString(names))));
+ return InvalidOid;
+ }
+
+ /*
+ * If, upon retry, we get back the same OID we did last time, then the
+ * invalidation messages we processed did not change the final answer.
+ * So we're done.
+ *
+ * If we got a different OID, we've locked the variable that used to
+ * have this name rather than the one that does now. So release the
+ * lock.
+ */
+ if (retry)
+ {
+ if (old_varid == varid)
+ break;
+
+ if (OidIsValid(old_varid))
+ UnlockDatabaseObject(VariableRelationId, old_varid, 0, AccessShareLock);
+ }
+
+ /*
+ * Lock the variable. This will also accept any pending invalidation
+ * messages. If we got back InvalidOid, indicating not found, then
+ * there's nothing to lock, but we accept invalidation messages
+ * anyway, to flush any negative catcache entries that may be
+ * lingering.
+ */
+ if (!OidIsValid(varid))
+ AcceptInvalidationMessages();
+ else
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ /*
+ * If no invalidation message were processed, we're done!
+ */
+ if (inval_count == SharedInvalidMessageCounter)
+ break;
+
+ retry = true;
+ old_varid = varid;
+ varid = InvalidOid;
+ }
+
+ return varid;
+}
+
/*
* DeconstructQualifiedName
* Given a possibly-qualified name expressed as a list of String nodes,
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 29d967a2d5b..bb445e9434b 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -26,6 +26,7 @@
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
+#include "utils/pg_lsn.h"
#include "utils/syscache.h"
static ObjectAddress create_variable(const char *varName,
@@ -101,6 +102,7 @@ create_variable(const char *varName,
varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varcreate_lsn - 1] = LSNGetDatum(GetXLogInsertRecPtr());
values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile
index 48f7348f91c..1cfaeca51ea 100644
--- a/src/backend/commands/Makefile
+++ b/src/backend/commands/Makefile
@@ -50,6 +50,7 @@ OBJS = \
schemacmds.o \
seclabel.o \
sequence.o \
+ session_variable.o \
statscmds.o \
subscriptioncmds.o \
tablecmds.o \
diff --git a/src/backend/commands/meson.build b/src/backend/commands/meson.build
index ef0d407a383..ce1619e3089 100644
--- a/src/backend/commands/meson.build
+++ b/src/backend/commands/meson.build
@@ -38,6 +38,7 @@ backend_sources += files(
'schemacmds.c',
'seclabel.c',
'sequence.c',
+ 'session_variable.c',
'statscmds.c',
'subscriptioncmds.c',
'tablecmds.c',
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 8989c0c882d..902b022f9c7 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -338,6 +338,16 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
i++;
}
+ /*
+ * The arguments of EXECUTE are evaluated by a direct expression
+ * executor call. This mode doesn't support session variables yet.
+ * It will be enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
/* Prepare the expressions for execution */
exprstates = ExecPrepareExprList(params, estate);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
new file mode 100644
index 00000000000..2456a3452b9
--- /dev/null
+++ b/src/backend/commands/session_variable.c
@@ -0,0 +1,529 @@
+/*-------------------------------------------------------------------------
+ *
+ * session_variable.c
+ * session variable creation/manipulation commands
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/commands/session_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "rewrite/rewriteHandler.h"
+#include "storage/lmgr.h"
+#include "storage/proc.h"
+#include "tcop/tcopprot.h"
+#include "utils/builtins.h"
+#include "utils/datum.h"
+#include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/snapmgr.h"
+#include "utils/syscache.h"
+
+/*
+ * The values of session variables are stored in the backend's private memory
+ * in the dedicated memory context SVariableMemoryContext in binary format.
+ * They are stored in the "sessionvars" hash table, whose key is the OID of the
+ * variable. However, the OID is not good enough to identify a session
+ * variable: concurrent sessions could drop the session variable and create a
+ * new one, which could be assigned the same OID. To ensure that the values
+ * stored in memory and the catalog definition match, we also keep track of
+ * the "create_lsn". Before any access to the variable values, we need to
+ * check if the LSN stored in memory matches the LSN in the catalog. If there
+ * is a mismatch between the LSNs, or if the OID is not present in pg_variable
+ * at all, the value stored in memory is released.
+ */
+typedef struct SVariableData
+{
+ Oid varid; /* pg_variable OID of the variable (hash key) */
+ XLogRecPtr create_lsn;
+
+ bool isnull;
+ Datum value;
+
+ Oid typid;
+ int16 typlen;
+ bool typbyval;
+
+ bool is_domain;
+
+ /*
+ * domain_check_extra holds cached domain metadata. This "extra" is
+ * usually stored in fn_mcxt. We do not have access to that memory context
+ * for session variables, but we can use TopTransactionContext instead.
+ * A fresh value is forced when we detect we are in a different transaction
+ * (the local transaction ID differs from domain_check_extra_lxid).
+ */
+ void *domain_check_extra;
+ LocalTransactionId domain_check_extra_lxid;
+
+ /*
+ * Stored value and type description can be outdated when we receive a
+ * sinval message. We then have to check if the stored data are still
+ * trustworthy.
+ */
+ bool is_valid;
+
+ uint32 hashvalue; /* used for pairing sinval message */
+} SVariableData;
+
+typedef SVariableData *SVariable;
+
+static HTAB *sessionvars = NULL; /* hash table for session variables */
+
+static MemoryContext SVariableMemoryContext = NULL;
+
+/*
+ * Callback function for session variable invalidation.
+ */
+static void
+pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
+
+ Assert(sessionvars);
+
+ /*
+ * If the hashvalue is not specified, we have to recheck all currently
+ * used session variables. Since we can't tell the exact session variable
+ * from its hashvalue, we have to iterate over all items in the hash bucket.
+ */
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (hashvalue == 0 || svar->hashvalue == hashvalue)
+ {
+ svar->is_valid = false;
+ }
+ }
+}
+
+/*
+ * Release stored value, free memory
+ */
+static void
+free_session_variable_value(SVariable svar)
+{
+ /* clean the current value */
+ if (!svar->isnull)
+ {
+ if (!svar->typbyval)
+ pfree(DatumGetPointer(svar->value));
+
+ svar->isnull = true;
+ }
+
+ svar->value = (Datum) 0;
+}
+
+/*
+ * Returns true when the entry in pg_variable is consistent with the given
+ * session variable.
+ */
+static bool
+is_session_variable_valid(SVariable svar)
+{
+ HeapTuple tp;
+ bool result = false;
+
+ Assert(OidIsValid(svar->varid));
+
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ /*
+ * The OID alone is not enough as an unique identifier, because OID
+ * values get recycled, and a new session variable could have got
+ * the same OID. We do a second check against the 64-bit LSN when
+ * the variable was created.
+ */
+ if (svar->create_lsn == ((Form_pg_variable) GETSTRUCT(tp))->varcreate_lsn)
+ result = true;
+
+ ReleaseSysCache(tp);
+ }
+
+ return result;
+}
+
+/*
+ * Initialize attributes cached in "svar"
+ */
+static void
+setup_session_variable(SVariable svar, Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ Assert(OidIsValid(varid));
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ svar->varid = varid;
+ svar->create_lsn = varform->varcreate_lsn;
+
+ svar->typid = varform->vartype;
+
+ get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval);
+
+ svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
+ svar->domain_check_extra = NULL;
+ svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+
+ svar->isnull = true;
+ svar->value = (Datum) 0;
+
+ svar->is_valid = true;
+
+ svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ ReleaseSysCache(tup);
+}
+
+/*
+ * Assign a new value to the session variable. It is copied to
+ * SVariableMemoryContext if necessary.
+ *
+ * If any error happens, the existing value won't be modified.
+ */
+static void
+set_session_variable(SVariable svar, Datum value, bool isnull)
+{
+ Datum newval;
+ SVariableData locsvar,
+ *_svar;
+
+ Assert(svar);
+ Assert(!isnull || value == (Datum) 0);
+
+ /*
+ * Use typbyval, typbylen from session variable only when they are
+ * trustworthy (the invalidation message was not accepted for this
+ * variable). If the variable might be invalid, force setup.
+ *
+ * Do not overwrite the passed session variable until we can be certain
+ * that no error can be thrown.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(&locsvar, svar->varid);
+ _svar = &locsvar;
+ }
+ else
+ _svar = svar;
+
+ if (!isnull)
+ {
+ MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
+
+ newval = datumCopy(value, _svar->typbyval, _svar->typlen);
+
+ MemoryContextSwitchTo(oldcxt);
+ }
+ else
+ newval = value;
+
+ free_session_variable_value(svar);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ svar->varid);
+
+ /* no more error expected, so we can overwrite the old variable now */
+ if (svar != _svar)
+ memcpy(svar, _svar, sizeof(SVariableData));
+
+ svar->value = newval;
+ svar->isnull = isnull;
+}
+
+/*
+ * Create the hash table for storing session variables.
+ */
+static void
+create_sessionvars_hashtables(void)
+{
+ HASHCTL vars_ctl;
+
+ Assert(!sessionvars);
+
+ if (!SVariableMemoryContext)
+ {
+ /* read sinval messages */
+ CacheRegisterSyscacheCallback(VARIABLEOID,
+ pg_variable_cache_callback,
+ (Datum) 0);
+
+ /* we need our own long-lived memory context */
+ SVariableMemoryContext =
+ AllocSetContextCreate(TopMemoryContext,
+ "session variables",
+ ALLOCSET_START_SMALL_SIZES);
+ }
+
+ memset(&vars_ctl, 0, sizeof(vars_ctl));
+ vars_ctl.keysize = sizeof(Oid);
+ vars_ctl.entrysize = sizeof(SVariableData);
+ vars_ctl.hcxt = SVariableMemoryContext;
+
+ sessionvars = hash_create("Session variables", 64, &vars_ctl,
+ HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+}
+
+/*
+ * Search a session variable in the hash table given its OID. If it
+ * doesn't exist, then insert it there.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the
+ * session variable until the end of the transaction.
+ */
+static SVariable
+get_session_variable(Oid varid)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect the used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (found)
+ {
+ if (!svar->is_valid)
+ {
+ /*
+ * If there was an invalidation message, the variable might still be
+ * valid, but we have to check with the system catalog.
+ */
+ if (is_session_variable_valid(svar))
+ svar->is_valid = true;
+ else
+ /* if the value cannot be validated, we have to discard it */
+ free_session_variable_value(svar);
+ }
+ }
+ else
+ svar->is_valid = false;
+
+ /*
+ * Force setup for not yet initialized variables or variables that cannot
+ * be validated.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ varid);
+ }
+
+ /* ensure the returned data is still of the correct domain */
+ if (svar->is_domain)
+ {
+ /*
+ * Store "extra" for domain_check() in TopTransactionContext. When we
+ * are in a new transaction, domain_check_extra cache is not valid any
+ * more.
+ */
+ if (svar->domain_check_extra_lxid != MyProc->vxid.lxid)
+ svar->domain_check_extra = NULL;
+
+ domain_check(svar->value, svar->isnull,
+ svar->typid, &svar->domain_check_extra,
+ TopTransactionContext);
+
+ svar->domain_check_extra_lxid = MyProc->vxid.lxid;
+ }
+
+ return svar;
+}
+
+/*
+ * Store the given value in a session variable in the cache.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the session
+ * variable until the end of the transaction.
+ */
+void
+SetSessionVariable(Oid varid, Datum value, bool isNull)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (!found)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ varid);
+ }
+
+ /* if this fails, it won't change the stored value */
+ set_session_variable(svar, value, isNull);
+}
+
+/*
+ * Returns a copy of the value stored in a variable.
+ */
+static inline Datum
+copy_session_variable_value(SVariable svar, bool *isNull)
+{
+ Datum value;
+
+ /* force copy of non NULL value */
+ if (!svar->isnull)
+ {
+ value = datumCopy(svar->value, svar->typbyval, svar->typlen);
+ *isNull = false;
+ }
+ else
+ {
+ value = (Datum) 0;
+ *isNull = true;
+ }
+
+ return value;
+}
+
+/*
+ * Returns a copy of the value of the session variable (in the current memory
+ * context). The caller is responsible for permission checks.
+ */
+Datum
+GetSessionVariable(Oid varid, bool *isNull)
+{
+ SVariable svar;
+
+ svar = get_session_variable(varid);
+
+ /*
+ * Although "svar" is freshly validated in this point, svar->is_valid can
+ * be false, if an invalidation message was processed during the domain check.
+ * But the variable and all its dependencies are locked now, so we don't need
+ * to repeat the validation.
+ */
+ return copy_session_variable_value(svar, isNull);
+}
+
+/*
+ * Assign the result of the evaluated expression to the session variable
+ */
+void
+ExecuteLetStmt(ParseState *pstate,
+ LetStmt *stmt,
+ ParamListInfo params,
+ QueryEnvironment *queryEnv,
+ QueryCompletion *qc)
+{
+ Query *query = castNode(Query, stmt->query);
+ List *rewritten;
+ DestReceiver *dest;
+ AclResult aclresult;
+ PlannedStmt *plan;
+ QueryDesc *queryDesc;
+ Oid varid = query->resultVariable;
+
+ Assert(OidIsValid(varid));
+
+ /* do we have permission to write to the session variable? */
+ aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid));
+
+ /* create a dest receiver for LET */
+ dest = CreateVariableDestReceiver(varid);
+
+ /* run the query rewriter */
+ query = copyObject(query);
+
+ rewritten = QueryRewrite(query);
+
+ Assert(list_length(rewritten) == 1);
+
+ query = linitial_node(Query, rewritten);
+ Assert(query->commandType == CMD_SELECT);
+
+ /* plan the query */
+ plan = pg_plan_query(query, pstate->p_sourcetext,
+ CURSOR_OPT_PARALLEL_OK, params);
+
+ /*
+ * Use a snapshot with an updated command ID to ensure this query sees the
+ * results of any previously executed queries. (This could only matter if
+ * the planner executed an allegedly-stable function that changed the
+ * database contents, but let's do it anyway to be parallel to the EXPLAIN
+ * code path.)
+ */
+ PushCopiedSnapshot(GetActiveSnapshot());
+ UpdateActiveSnapshotCommandId();
+
+ /* create a QueryDesc, redirecting output to our tuple receiver */
+ queryDesc = CreateQueryDesc(plan, pstate->p_sourcetext,
+ GetActiveSnapshot(), InvalidSnapshot,
+ dest, params, queryEnv, 0);
+
+ /* call ExecutorStart to prepare the plan for execution */
+ ExecutorStart(queryDesc, 0);
+
+ /*
+ * Run the plan to completion. The result should be only one row. To
+ * check if there are too many result rows, we try to fetch two.
+ */
+ ExecutorRun(queryDesc, ForwardScanDirection, 2L);
+
+ /* save the rowcount if we're given a QueryCompletion to fill */
+ if (qc)
+ SetQueryCompletion(qc, CMDTAG_LET, queryDesc->estate->es_processed);
+
+ /* and clean up */
+ ExecutorFinish(queryDesc);
+ ExecutorEnd(queryDesc);
+
+ FreeQueryDesc(queryDesc);
+
+ PopActiveSnapshot();
+}
diff --git a/src/backend/executor/Makefile b/src/backend/executor/Makefile
index 11118d0ce02..71248a34f26 100644
--- a/src/backend/executor/Makefile
+++ b/src/backend/executor/Makefile
@@ -76,6 +76,7 @@ OBJS = \
nodeWindowAgg.o \
nodeWorktablescan.o \
spi.o \
+ svariableReceiver.o \
tqueue.o \
tstoreReceiver.o
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 03566c4d181..270e6d344be 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -1041,6 +1041,38 @@ ExecInitExprRec(Expr *node, ExprState *state,
scratch.d.param.paramtype = param->paramtype;
ExprEvalPushStep(state, &scratch);
break;
+
+ case PARAM_VARIABLE:
+ {
+ int es_num_session_variables = 0;
+ SessionVariableValue *es_session_variables = NULL;
+ SessionVariableValue *var;
+
+ if (state->parent && state->parent->state)
+ {
+ es_session_variables = state->parent->state->es_session_variables;
+ es_num_session_variables = state->parent->state->es_num_session_variables;
+ }
+
+ Assert(es_session_variables);
+
+ /* parameter sanity checks */
+ if (param->paramid >= es_num_session_variables)
+ elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
+
+ var = &es_session_variables[param->paramid];
+
+ /*
+ * In this case, pass the value like a
+ * constant.
+ */
+ scratch.opcode = EEOP_CONST;
+ scratch.d.constval.value = var->value;
+ scratch.d.constval.isnull = var->isnull;
+ ExprEvalPushStep(state, &scratch);
+ }
+ break;
+
case PARAM_EXTERN:
/*
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 963aa390620..35f89dc4212 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -43,7 +43,9 @@
#include "access/xact.h"
#include "catalog/namespace.h"
#include "catalog/partition.h"
+#include "catalog/pg_variable.h"
#include "commands/matview.h"
+#include "commands/session_variable.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/execPartition.h"
@@ -194,6 +196,70 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
Assert(queryDesc->sourceText != NULL);
estate->es_sourceText = queryDesc->sourceText;
+ /*
+ * The executor doesn't work with session variables directly. Values of
+ * related session variables are copied to a dedicated array, and this array
+ * is passed to the executor. This array is stable "snapshot" of values of
+ * used session variables. There are three benefits of this strategy:
+ *
+ * - consistency with external parameters and plpgsql variables,
+ *
+ * - session variables can be parallel safe,
+ *
+ * - we don't need make fresh copy for any read of session variable
+ * (this is necessary because the internally the session variable can
+ * be changed inside query execution time, and then a reference to
+ * previously returned value can be corrupted).
+ */
+ if (queryDesc->plannedstmt->sessionVariables)
+ {
+ int nSessionVariables;
+ int i = 0;
+
+ /*
+ * In this case, the query uses session variables, but we have to
+ * prepare the array with passed values (of used session variables)
+ * first.
+ */
+ Assert(!IsParallelWorker());
+ nSessionVariables = list_length(queryDesc->plannedstmt->sessionVariables);
+
+ /* create the array used for passing values of used session variables */
+ estate->es_session_variables = (SessionVariableValue *)
+ palloc(nSessionVariables * sizeof(SessionVariableValue));
+
+ /* fill the array */
+ foreach_oid(varid, queryDesc->plannedstmt->sessionVariables)
+ {
+ /*
+ * Permission check should be executed on all explicitly used
+ * variables in the query. For implicitly used variable
+ * (like base node of assignment indirect) we cannot do permission
+ * check, because we need read the value (and user can have
+ * only UPDATE variable). In this case the permission check
+ * is executed in write time.
+ */
+ if (varid != queryDesc->plannedstmt->exclSelectPermCheckVarid)
+ {
+ AclResult aclresult;
+
+ aclresult = object_aclcheck(VariableRelationId, varid,
+ GetUserId(), ACL_SELECT);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE,
+ get_session_variable_name(varid));
+ }
+
+ estate->es_session_variables[i].value =
+ GetSessionVariable(varid,
+ &estate->es_session_variables[i].isnull);
+
+ i++;
+ }
+
+ estate->es_num_session_variables = nSessionVariables;
+ }
+
/*
* Fill in the query environment, if any, from queryDesc.
*/
diff --git a/src/backend/executor/meson.build b/src/backend/executor/meson.build
index 2cea41f8771..491092fcc4c 100644
--- a/src/backend/executor/meson.build
+++ b/src/backend/executor/meson.build
@@ -64,6 +64,7 @@ backend_sources += files(
'nodeWindowAgg.c',
'nodeWorktablescan.c',
'spi.c',
+ 'svariableReceiver.c',
'tqueue.c',
'tstoreReceiver.c',
)
diff --git a/src/backend/executor/svariableReceiver.c b/src/backend/executor/svariableReceiver.c
new file mode 100644
index 00000000000..c6163fb36f6
--- /dev/null
+++ b/src/backend/executor/svariableReceiver.c
@@ -0,0 +1,172 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.c
+ * An implementation of DestReceiver that stores the result value in
+ * a session variable.
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/executor/svariableReceiver.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "miscadmin.h"
+
+#include "access/detoast.h"
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "storage/lock.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+/*
+ * This DestReceiver is used by the LET command for storing the result to a
+ * session variable. The result has to have only one tuple with only one
+ * non-deleted attribute. The row counter (field "rows") is incremented
+ * after receiving a row, and an error is raised when there are no rows or
+ * there are more than one received rows. A received tuple cannot to have
+ * deleted attributes. The value is detoasted before storing it in the
+ * session variable.
+ */
+typedef struct
+{
+ DestReceiver pub;
+ Oid varid;
+ bool need_detoast; /* do we need to detoast the attribute? */
+ int rows; /* row counter */
+} SVariableState;
+
+/*
+ * Prepare to receive tuples from executor.
+ */
+static void
+svariableStartupReceiver(DestReceiver *self, int operation, TupleDesc typeinfo)
+{
+ SVariableState *myState = (SVariableState *) self;
+ LOCKTAG locktag PG_USED_FOR_ASSERTS_ONLY;
+ Form_pg_attribute attr;
+ Oid typid PG_USED_FOR_ASSERTS_ONLY;
+ Oid collid PG_USED_FOR_ASSERTS_ONLY;
+ int32 typmod PG_USED_FOR_ASSERTS_ONLY;
+
+ Assert(myState->pub.mydest == DestVariable);
+ Assert(OidIsValid(myState->varid));
+ Assert(SearchSysCacheExists1(VARIABLEOID, myState->varid));
+ Assert(typeinfo->natts == 1);
+
+#ifdef USE_ASSERT_CHECKING
+
+ SET_LOCKTAG_OBJECT(locktag,
+ MyDatabaseId,
+ VariableRelationId,
+ myState->varid,
+ 0);
+
+ Assert(LockHeldByMe(&locktag, AccessShareLock, false));
+
+#endif
+
+ attr = TupleDescAttr(typeinfo, 0);
+
+ Assert(!attr->attisdropped);
+
+#ifdef USE_ASSERT_CHECKING
+
+ get_session_variable_type_typmod_collid(myState->varid,
+ &typid,
+ &typmod,
+ &collid);
+
+ Assert(attr->atttypid == typid);
+ Assert(attr->atttypmod < 0 || attr->atttypmod == typmod);
+
+#endif
+
+ myState->need_detoast = attr->attlen == -1;
+ myState->rows = 0;
+}
+
+/*
+ * Receive a tuple from the executor and store it in the session variable.
+ */
+static bool
+svariableReceiveSlot(TupleTableSlot *slot, DestReceiver *self)
+{
+ SVariableState *myState = (SVariableState *) self;
+ Datum value;
+ bool isnull;
+ bool freeval = false;
+
+ /* make sure the tuple is fully deconstructed */
+ slot_getallattrs(slot);
+
+ value = slot->tts_values[0];
+ isnull = slot->tts_isnull[0];
+
+ if (myState->need_detoast && !isnull && VARATT_IS_EXTERNAL(DatumGetPointer(value)))
+ {
+ value = PointerGetDatum(detoast_external_attr((struct varlena *)
+ DatumGetPointer(value)));
+ freeval = true;
+ }
+
+ myState->rows += 1;
+
+ if (myState->rows > 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_TOO_MANY_ROWS),
+ errmsg("expression returned more than one row")));
+
+ SetSessionVariable(myState->varid, value, isnull);
+
+ if (freeval)
+ pfree(DatumGetPointer(value));
+
+ return true;
+}
+
+/*
+ * Clean up at end of the executor run
+ */
+static void
+svariableShutdownReceiver(DestReceiver *self)
+{
+ if (((SVariableState *) self)->rows == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_NO_DATA_FOUND),
+ errmsg("expression returned no rows")));
+}
+
+/*
+ * Destroy the receiver when we are done with it
+ */
+static void
+svariableDestroyReceiver(DestReceiver *self)
+{
+ pfree(self);
+}
+
+/*
+ * Initially create a DestReceiver object.
+ */
+DestReceiver *
+CreateVariableDestReceiver(Oid varid)
+{
+ SVariableState *self = (SVariableState *) palloc0(sizeof(SVariableState));
+
+ self->pub.receiveSlot = svariableReceiveSlot;
+ self->pub.rStartup = svariableStartupReceiver;
+ self->pub.rShutdown = svariableShutdownReceiver;
+ self->pub.rDestroy = svariableDestroyReceiver;
+ self->pub.mydest = DestVariable;
+
+ self->varid = varid;
+
+ return (DestReceiver *) self;
+}
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f1..d8fc3d9fa69 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4375,6 +4375,16 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_LetStmt:
+ {
+ LetStmt *stmt = (LetStmt *) node;
+
+ if (WALK(stmt->target))
+ return true;
+ if (WALK(stmt->query))
+ return true;
+ }
+ break;
case T_PLAssignStmt:
{
PLAssignStmt *stmt = (PLAssignStmt *) node;
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 7b1a8a0a9f1..cf094987569 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -333,6 +333,21 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
glob->lastPlanNodeId = 0;
glob->transientPlan = false;
glob->dependsOnRole = false;
+ glob->sessionVariables = NIL;
+
+ /*
+ * The (session) result variable should be stored to global, because
+ * it is not set in subquery. When this variable is used other than
+ * in base node of assignment indirection, we need to check the access
+ * rights (and then we need to detect this situation). The variable used
+ * like base node cannot be different than target (result) variable.
+ * Because we know the result variable before planner invocation, we
+ * can simply search of usage just this variable, and we don't need to
+ * to wait until the end of planning when we know basenodeSessionVarid.
+ */
+ glob->resultVariable = parse->resultVariable;
+ glob->basenodeSessionVarid = InvalidOid;
+ glob->basenodeSessionVarSelectCheck = false;
/*
* Assess whether it's feasible to use parallel mode for this query. We
@@ -570,6 +585,20 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
result->paramExecTypes = glob->paramExecTypes;
/* utilityStmt should be null, but we might as well copy it */
result->utilityStmt = parse->utilityStmt;
+
+ result->sessionVariables = glob->sessionVariables;
+
+ /*
+ * The session variable used (and only used) like base node
+ * for assignemnt indirection should be excluded from permission
+ * check.
+ */
+ if (OidIsValid(glob->basenodeSessionVarid) &&
+ (!glob->basenodeSessionVarSelectCheck))
+ result->exclSelectPermCheckVarid = glob->basenodeSessionVarid;
+ else
+ result->exclSelectPermCheckVarid = InvalidOid;
+
result->stmt_location = parse->stmt_location;
result->stmt_len = parse->stmt_len;
@@ -740,6 +769,13 @@ subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root,
*/
pull_up_subqueries(root);
+ /*
+ * Check if some subquery uses a session variable. The flag
+ * hasSessionVariables should be true if the query or some subquery uses a
+ * session variable.
+ */
+ pull_up_has_session_variables(root);
+
/*
* If this is a simple UNION ALL query, flatten it into an appendrel. We
* do this now because it requires applying pull_up_subqueries to the leaf
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 999a5a8ab5a..dc2caa520f7 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -210,6 +210,9 @@ static List *set_returning_clause_references(PlannerInfo *root,
static List *set_windowagg_runcondition_references(PlannerInfo *root,
List *runcondition,
Plan *plan);
+static bool pull_up_has_session_variables_walker(Node *node,
+ PlannerInfo *root);
+static void record_plan_variable_dependency(PlannerInfo *root, Oid varid);
/*****************************************************************************
@@ -1315,6 +1318,50 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
return plan;
}
+/*
+ * Search usage of session variables in subqueries
+ */
+void
+pull_up_has_session_variables(PlannerInfo *root)
+{
+ Query *query = root->parse;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ }
+ else
+ {
+ (void) query_tree_walker(query,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+}
+
+static bool
+pull_up_has_session_variables_walker(Node *node, PlannerInfo *root)
+{
+ if (node == NULL)
+ return false;
+ if (IsA(node, Query))
+ {
+ Query *query = (Query *) node;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ return false;
+ }
+
+ /* recurse into subselects */
+ return query_tree_walker((Query *) node,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+ return expression_tree_walker(node, pull_up_has_session_variables_walker,
+ (void *) root);
+}
+
/*
* set_indexonlyscan_references
* Do set_plan_references processing on an IndexOnlyScan
@@ -2015,8 +2062,9 @@ copyVar(Var *var)
* This is code that is common to all variants of expression-fixing.
* We must look up operator opcode info for OpExpr and related nodes,
* add OIDs from regclass Const nodes into root->glob->relationOids, and
- * add PlanInvalItems for user-defined functions into root->glob->invalItems.
- * We also fill in column index lists for GROUPING() expressions.
+ * add PlanInvalItems for user-defined functions and session variables into
+ * root->glob->invalItems. We also fill in column index lists for GROUPING()
+ * expressions.
*
* We assume it's okay to update opcode info in-place. So this could possibly
* scribble on the planner's input data structures, but it's OK.
@@ -2106,6 +2154,13 @@ fix_expr_common(PlannerInfo *root, Node *node)
g->cols = cols;
}
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ record_plan_variable_dependency(root, p->paramvarid);
+ }
}
/*
@@ -2115,6 +2170,10 @@ fix_expr_common(PlannerInfo *root, Node *node)
* If it's a PARAM_MULTIEXPR, replace it with the appropriate Param from
* root->multiexpr_params; otherwise no change is needed.
* Just for paranoia's sake, we make a copy of the node in either case.
+ *
+ * If it's a PARAM_VARIABLE, then we collect used session variables in
+ * the list root->glob->sessionVariable. Also, assign the parameter's
+ * "paramid" to the parameter's position in that list.
*/
static Node *
fix_param_node(PlannerInfo *root, Param *p)
@@ -2133,6 +2192,62 @@ fix_param_node(PlannerInfo *root, Param *p)
elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid);
return copyObject(list_nth(params, colno - 1));
}
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ int n = 0;
+ bool found = false;
+
+ /* we will modify object */
+ p = (Param *) copyObject(p);
+
+ /*
+ * Now, we can actualize list of session variables, and we can
+ * complete paramid parameter.
+ */
+ foreach_oid(varid, root->glob->sessionVariables)
+ {
+ if (varid == p->paramvarid)
+ {
+ p->paramid = n;
+ found = true;
+ break;
+ }
+ n += 1;
+ }
+
+ if (!found)
+ {
+ root->glob->sessionVariables = lappend_oid(root->glob->sessionVariables,
+ p->paramvarid);
+ p->paramid = n;
+ }
+
+ /*
+ * We do SELECT permission check of all variables used by
+ * the query excluding the variable that is used only as base node
+ * of assignment indirection. The variable id assigned to this param
+ * should be same like resultVariable id, and this param should be
+ * used only once in query. When the variable is referenced by any
+ * other param, we should to do SELECT permission check for this variable
+ * too.
+ */
+ if (p->parambasenode)
+ {
+ Assert(!OidIsValid(root->glob->basenodeSessionVarid));
+ Assert(root->glob->resultVariable == p->paramvarid);
+
+ root->glob->basenodeSessionVarid = p->paramvarid;
+ }
+ else
+ {
+ if (p->paramvarid == root->glob->resultVariable)
+ root->glob->basenodeSessionVarSelectCheck = true;
+ }
+
+ return (Node *) p;
+ }
+
return (Node *) copyObject(p);
}
@@ -2194,7 +2309,10 @@ fix_alternative_subplan(PlannerInfo *root, AlternativeSubPlan *asplan,
* replacing Aggref nodes that should be replaced by initplan output Params,
* choosing the best implementation for AlternativeSubPlans,
* looking up operator opcode info for OpExpr and related nodes,
- * and adding OIDs from regclass Const nodes into root->glob->relationOids.
+ * adding OIDs from regclass Const nodes into root->glob->relationOids,
+ * assigning paramvarid to PARAM_VARIABLE params, and collecting the
+ * OIDs of session variables in the root->glob->sessionVariables list
+ * (paramvarid is the position of the session variable in this list).
*
* 'node': the expression to be modified
* 'rtoffset': how much to increment varnos by
@@ -2216,7 +2334,8 @@ fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec)
root->multiexpr_params != NIL ||
root->glob->lastPHId != 0 ||
root->minmax_aggs != NIL ||
- root->hasAlternativeSubPlans)
+ root->hasAlternativeSubPlans ||
+ root->hasSessionVariables)
{
return fix_scan_expr_mutator(node, &context);
}
@@ -3609,6 +3728,25 @@ record_plan_type_dependency(PlannerInfo *root, Oid typid)
}
}
+/*
+ * Record dependency on a session variable. The variable can be used as a
+ * session variable in an expression list, or as the target of a LET statement.
+ */
+static void
+record_plan_variable_dependency(PlannerInfo *root, Oid varid)
+{
+ PlanInvalItem *inval_item = makeNode(PlanInvalItem);
+
+ /* paramid is still session variable id */
+ inval_item->cacheId = VARIABLEOID;
+ inval_item->hashValue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ /* append this variable to global, register dependency */
+ root->glob->invalItems = lappend(root->glob->invalItems,
+ inval_item);
+}
+
/*
* extract_query_dependencies
* Given a rewritten, but not yet planned, query or queries
@@ -3694,9 +3832,9 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
}
/*
- * Ignore other utility statements, except those (such as EXPLAIN)
- * that contain a parsed-but-not-planned query. For those, we
- * just need to transfer our attention to the contained query.
+ * Ignore other utility statements, except those (such as EXPLAIN
+ * or LET) that contain a parsed-but-not-planned query. For those,
+ * we just need to transfer our attention to the contained query.
*/
query = UtilityContainsQuery(query->utilityStmt);
if (query == NULL)
@@ -3719,6 +3857,10 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
lappend_oid(context->glob->relationOids, rte->relid);
}
+ /* record dependency on the target variable of a LET command */
+ if (OidIsValid(query->resultVariable))
+ record_plan_variable_dependency(context, query->resultVariable);
+
/* And recurse into the query's subexpressions */
return query_tree_walker(query, extract_query_dependencies_walker,
context, 0);
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index 5d9225e9909..71479ceb1bc 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -1432,6 +1432,9 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
/* If subquery had any RLS conditions, now main query does too */
parse->hasRowSecurity |= subquery->hasRowSecurity;
+ /* if the subquery had session variables, the main query does too */
+ parse->hasSessionVariables |= subquery->hasSessionVariables;
+
/*
* subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
* hasTargetSRFs, so no work needed on those flags
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 43dfecfb47f..f60828f862e 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -24,6 +24,7 @@
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "commands/session_variable.h"
#include "executor/executor.h"
#include "executor/functions.h"
#include "funcapi.h"
@@ -934,6 +935,13 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
if (param->paramkind == PARAM_EXTERN)
return false;
+ /* we don't support passing session variables to workers */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
+ return true;
+ }
+
if (param->paramkind != PARAM_EXEC ||
!list_member_int(context->safe_param_ids, param->paramid))
{
@@ -2389,6 +2397,7 @@ convert_saop_to_hashed_saop_walker(Node *node, void *context)
* value of the Param.
* 2. Fold stable, as well as immutable, functions to constants.
* 3. Reduce PlaceHolderVar nodes to their contained expressions.
+ * 4. Current value of session variable can be used for estimation too.
*--------------------
*/
Node *
@@ -2515,6 +2524,27 @@ eval_const_expressions_mutator(Node *node,
}
}
}
+ else if (param->paramkind == PARAM_VARIABLE &&
+ context->estimate)
+ {
+ int16 typLen;
+ bool typByVal;
+ Datum pval;
+ bool isnull;
+
+ get_typlenbyval(param->paramtype,
+ &typLen, &typByVal);
+
+ pval = GetSessionVariable(param->paramvarid, &isnull);
+
+ return (Node *) makeConst(param->paramtype,
+ param->paramtypmod,
+ param->paramcollid,
+ (int) typLen,
+ pval,
+ isnull,
+ typByVal);
+ }
/*
* Not replaceable, so just copy the Param (no need to
@@ -4720,7 +4750,8 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
querytree->limitOffset ||
querytree->limitCount ||
querytree->setOperations ||
- list_length(querytree->targetList) != 1)
+ (list_length(querytree->targetList) != 1) ||
+ querytree->hasSessionVariables)
goto fail;
/* If the function result is composite, resolve it */
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 76f58b3aca3..725f678e2fa 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -25,9 +25,12 @@
#include "postgres.h"
#include "access/sysattr.h"
+#include "catalog/namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
@@ -51,6 +54,7 @@
#include "utils/backend_status.h"
#include "utils/builtins.h"
#include "utils/guc.h"
+#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
@@ -83,6 +87,8 @@ static Query *transformCreateTableAsStmt(ParseState *pstate,
CreateTableAsStmt *stmt);
static Query *transformCallStmt(ParseState *pstate,
CallStmt *stmt);
+static Query *transformLetStmt(ParseState *pstate,
+ LetStmt *stmt);
static void transformLockingClause(ParseState *pstate, Query *qry,
LockingClause *lc, bool pushedDown);
#ifdef DEBUG_NODE_TESTS_ENABLED
@@ -414,6 +420,7 @@ transformStmt(ParseState *pstate, Node *parseTree)
case T_UpdateStmt:
case T_DeleteStmt:
case T_MergeStmt:
+ case T_LetStmt:
(void) test_raw_expression_coverage(parseTree, NULL);
break;
default:
@@ -493,6 +500,11 @@ transformStmt(ParseState *pstate, Node *parseTree)
(CallStmt *) parseTree);
break;
+ case T_LetStmt:
+ result = transformLetStmt(pstate,
+ (LetStmt *) parseTree);
+ break;
+
default:
/*
@@ -545,6 +557,7 @@ stmt_requires_parse_analysis(RawStmt *parseTree)
case T_SelectStmt:
case T_ReturnStmt:
case T_PLAssignStmt:
+ case T_LetStmt:
result = true;
break;
@@ -653,6 +666,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1078,6 +1092,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1543,6 +1558,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, stmt->lockingClause)
{
@@ -1769,12 +1785,241 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
return qry;
}
+/*
+ * transformLetStmt -
+ * transform an Let Statement
+ */
+static Query *
+transformLetStmt(ParseState *pstate, LetStmt *stmt)
+{
+ Query *query;
+ Query *result;
+ List *exprList = NIL;
+ List *exprListCoer = NIL;
+ ListCell *lc;
+ ListCell *indirection_head = NULL;
+ Query *selectQuery;
+ Oid varid;
+ char *attrname = NULL;
+ bool not_unique;
+ bool is_rowtype;
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+ List *names = NULL;
+ int indirection_start;
+ int i = 0;
+
+ /* there can't be any outer WITH to worry about */
+ Assert(pstate->p_ctenamespace == NIL);
+
+ names = NamesFromList(stmt->target);
+
+ /* locks the variable with an AccessShareLock */
+ varid = IdentifyVariable(names, &attrname, ¬_unique, false);
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("target \"%s\" of LET command is ambiguous",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ if (!OidIsValid(varid))
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ /*
+ * Calculate start of possible position of an indirection in list, and
+ * when it is inside the list, store pointer on first node of indirection.
+ */
+ indirection_start = list_length(names) - (attrname ? 1 : 0);
+ if (list_length(stmt->target) > indirection_start)
+ indirection_head = list_nth_cell(stmt->target, indirection_start);
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod, &collid);
+
+ is_rowtype = type_is_rowtype(typid);
+
+ if (attrname && !is_rowtype)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("cannot assign to field \"%s\" of session variable \"%s.%s\" because its type %s is not a composite type",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->location)));
+
+ pstate->p_expr_kind = EXPR_KIND_LET_TARGET;
+
+ /* we need to postpone conversion of "unknown" to text */
+ pstate->p_resolve_unknowns = false;
+
+ selectQuery = transformStmt(pstate, stmt->query);
+
+ /* the grammar should have produced a SELECT */
+ Assert(IsA(selectQuery, Query) && selectQuery->commandType == CMD_SELECT);
+
+ /*
+ * Generate an expression list for the LET that selects all the non-resjunk
+ * columns from the subquery.
+ */
+ exprList = NIL;
+ foreach_node(TargetEntry, tle, selectQuery->targetList)
+ {
+ if (tle->resjunk)
+ continue;
+
+ exprList = lappend(exprList, tle->expr);
+ }
+
+ /* don't allow multicolumn result */
+ if (list_length(exprList) != 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg_plural("assignment expression returned %d column",
+ "assignment expression returned %d columns",
+ list_length(exprList),
+ list_length(exprList)),
+ parser_errposition(pstate,
+ exprLocation((Node *) exprList))));
+
+ exprListCoer = NIL;
+
+ foreach(lc, exprList)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ Expr *coerced_expr;
+ Oid exprtypid;
+
+ /* now we can read the type of the expression */
+ exprtypid = exprType((Node *) expr);
+
+ if (indirection_head)
+ {
+ bool targetIsArray;
+ char *targetName;
+ Param *param;
+
+ targetName = get_session_variable_name(varid);
+ targetIsArray = OidIsValid(get_element_type(typid));
+
+ pstate->p_hasSessionVariables = true;
+
+ param = makeNode(Param);
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+
+ /*
+ * The parameter used as basenode has to have special
+ * mark, because requires special access when we do
+ * SELECT access check.
+ */
+ param->parambasenode = true;
+
+ coerced_expr = (Expr *)
+ transformAssignmentIndirection(pstate,
+ (Node *) param,
+ targetName,
+ targetIsArray,
+ typid,
+ typmod,
+ InvalidOid,
+ stmt->target,
+ indirection_head,
+ (Node *) expr,
+ COERCION_ASSIGNMENT,
+ stmt->location);
+ }
+ else
+ coerced_expr = (Expr *)
+ coerce_to_target_type(pstate,
+ (Node *) expr,
+ exprtypid,
+ typid, typmod,
+ COERCION_ASSIGNMENT,
+ COERCE_IMPLICIT_CAST,
+ stmt->location);
+
+ if (coerced_expr == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("variable \"%s.%s\" is of type %s, but expression is of type %s",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid),
+ format_type_be(exprtypid)),
+ errhint("You will need to rewrite or cast the expression."),
+ parser_errposition(pstate, exprLocation((Node *) expr))));
+
+ exprListCoer = lappend(exprListCoer, coerced_expr);
+ }
+
+ /* generate query's target list using the computed list of expressions */
+ query = makeNode(Query);
+ query->commandType = CMD_SELECT;
+
+ foreach(lc, exprListCoer)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ TargetEntry *tle;
+
+ tle = makeTargetEntry(expr,
+ i + 1,
+ FigureColname((Node *) expr),
+ false);
+ query->targetList = lappend(query->targetList, tle);
+ }
+
+ /* done building the range table and jointree */
+ query->rtable = pstate->p_rtable;
+ query->jointree = makeFromExpr(pstate->p_joinlist, NULL);
+
+ query->hasTargetSRFs = pstate->p_hasTargetSRFs;
+ query->hasSubLinks = pstate->p_hasSubLinks;
+ query->hasSessionVariables = pstate->p_hasSessionVariables;
+
+ /* this is top-level query */
+ query->canSetTag = true;
+
+ /*
+ * Save target session variable ID. It is used later for
+ * acquiring an AccessShareLock on target variable, setting
+ * plan dependency and finally for creating VariableDestReceiver.
+ */
+ query->resultVariable = varid;
+
+ assign_query_collations(pstate, query);
+
+ /*
+ * The query is executed as utility command by nested executor call.
+ * Assigned queryId is required in this case.
+ */
+ if (IsQueryIdEnabled())
+ JumbleQuery(query);
+
+ stmt->query = (Node *) query;
+
+ /* represent the command as a utility Query */
+ result = makeNode(Query);
+ result->commandType = CMD_UTILITY;
+ result->utilityStmt = (Node *) stmt;
+
+ return result;
+}
+
/*
* transformSetOperationStmt -
* transforms a set-operations tree
@@ -2020,6 +2265,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, lockingClause)
{
@@ -2495,6 +2741,7 @@ transformReturnStmt(ParseState *pstate, ReturnStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2562,6 +2809,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2852,9 +3100,15 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
/*
* Transform the target reference. Typically we will get back a Param
* node, but there's no reason to be too picky about its type.
+ *
+ * Session variables should not be used as target of a PL/pgSQL assign
+ * statement. So we should use a dedicated expression kind and disallow
+ * session variables there. The dedicated context allows to eliminate
+ * undesirable warnings about the possibility of a target PL/pgSQL variable
+ * shadowing a session variable.
*/
target = transformExpr(pstate, (Node *) cref,
- EXPR_KIND_UPDATE_TARGET);
+ EXPR_KIND_ASSIGN_TARGET);
targettype = exprType(target);
targettypmod = exprTypmod(target);
targetcollation = exprCollation(target);
@@ -2896,6 +3150,10 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
*/
type_id = exprType((Node *) tle->expr);
+ /*
+ * For indirection processing and additional casts we can use expr_kind
+ * EXPR_KIND_UPDATE_TARGET.
+ */
pstate->p_expr_kind = EXPR_KIND_UPDATE_TARGET;
if (indirection)
@@ -3038,6 +3296,8 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
(LockingClause *) lfirst(l), false);
}
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
+
assign_query_collations(pstate, qry);
/* this must be done after collations, for reliable comparison of exprs */
@@ -3311,6 +3571,16 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt)
true,
stmt->funccall->location);
+ /*
+ * The arguments of CALL statement are evaluated by a direct expression
+ * executor call. This path is unsupported yet, so block it. It will be
+ * enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
assign_expr_collations(pstate, node);
fexpr = castNode(FuncExpr, node);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 2de2022b281..d34ea39bc83 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -297,7 +297,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
DropTransformStmt
DropUserMappingStmt ExplainStmt FetchStmt
GrantStmt GrantRoleStmt ImportForeignSchemaStmt IndexStmt InsertStmt
- ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
+ LetStmt ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
CreateFunctionStmt AlterFunctionStmt ReindexStmt RemoveAggrStmt
RemoveFuncStmt RemoveOperStmt RenameStmt ReturnStmt RevokeStmt RevokeRoleStmt
RuleActionStmt RuleActionStmtOrEmpty RuleStmt
@@ -742,7 +742,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
KEEP KEY KEYS
LABEL LANGUAGE LARGE_P LAST_P LATERAL_P
- LEADING LEAKPROOF LEAST LEFT LEVEL LIKE LIMIT LISTEN LOAD LOCAL
+ LEADING LEAKPROOF LEAST LEFT LET LEVEL LIKE LIMIT LISTEN LOAD LOCAL
LOCALTIME LOCALTIMESTAMP LOCATION LOCK_P LOCKED LOGGED
MAPPING MATCH MATCHED MATERIALIZED MAXVALUE MERGE MERGE_ACTION METHOD
@@ -1089,6 +1089,7 @@ stmt:
| ImportForeignSchemaStmt
| IndexStmt
| InsertStmt
+ | LetStmt
| ListenStmt
| RefreshMatViewStmt
| LoadStmt
@@ -12845,6 +12846,38 @@ opt_hold: /* EMPTY */ { $$ = 0; }
| WITHOUT HOLD { $$ = 0; }
;
+/*****************************************************************************
+ *
+ * QUERY:
+ * LET STATEMENT
+ *
+ *****************************************************************************/
+LetStmt: LET ColId opt_indirection '=' a_expr
+ {
+ LetStmt *n = makeNode(LetStmt);
+ SelectStmt *select;
+ ResTarget *res;
+
+ n->target = lcons(makeString($2),
+ check_indirection($3, yyscanner));
+
+ select = makeNode(SelectStmt);
+ res = makeNode(ResTarget);
+
+ /* create target list for implicit query */
+ res->name = NULL;
+ res->indirection = NIL;
+ res->val = (Node *) $5;
+ res->location = @5;
+
+ select->targetList = list_make1(res);
+ n->query = (Node *) select;
+
+ n->location = @2;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* QUERY:
@@ -17916,6 +17949,7 @@ unreserved_keyword:
| LARGE_P
| LAST_P
| LEAKPROOF
+ | LET
| LEVEL
| LISTEN
| LOAD
@@ -18529,6 +18563,7 @@ bare_label_keyword:
| LEAKPROOF
| LEAST
| LEFT
+ | LET
| LEVEL
| LIKE
| LISTEN
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 9e567f3cc45..4737b04d171 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -580,6 +580,11 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
+
/*
* There is intentionally no default: case here, so that the
* compiler will warn if we add a new ParseExprKind without
@@ -970,6 +975,10 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
case EXPR_KIND_CYCLE_MARK:
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index bad1df732ea..4f208c7efdd 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -17,6 +17,7 @@
#include "catalog/pg_aggregate.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
@@ -33,11 +34,13 @@
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "parser/parse_type.h"
+#include "storage/lmgr.h"
#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/timestamp.h"
+#include "utils/typcache.h"
#include "utils/xml.h"
/* GUC parameters */
@@ -106,6 +109,9 @@ static Expr *make_distinct_op(ParseState *pstate, List *opname,
Node *ltree, Node *rtree, int location);
static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
+static Node *makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location);
/*
@@ -499,6 +505,89 @@ transformIndirection(ParseState *pstate, A_Indirection *ind)
return result;
}
+/*
+ * Returns true if the given expression kind is valid for session variables.
+ * Session variables can be used everywhere where external parameters can be
+ * used. Session variables are not allowed in DDL commands or in constraints.
+ *
+ * An identifier can be parsed as a session variable only for expression kinds
+ * where session variables are allowed. This is the primary usage of this
+ * function.
+ *
+ * The second usage of this function is to decide whether a "column does not
+ * exist" or a "column or variable does not exist" error message should be
+ * printed. When we are in an expression where session variables cannot be
+ * used, we raise the first form of error message.
+ */
+static bool
+expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
+{
+ bool result = false;
+
+ switch (p_expr_kind)
+ {
+ case EXPR_KIND_NONE:
+ Assert(false); /* can't happen */
+ return false;
+
+ /* session variables allowed */
+ case EXPR_KIND_OTHER:
+ case EXPR_KIND_JOIN_ON:
+ case EXPR_KIND_FROM_SUBSELECT:
+ case EXPR_KIND_FROM_FUNCTION:
+ case EXPR_KIND_WHERE:
+ case EXPR_KIND_HAVING:
+ case EXPR_KIND_FILTER:
+ case EXPR_KIND_WINDOW_PARTITION:
+ case EXPR_KIND_WINDOW_ORDER:
+ case EXPR_KIND_WINDOW_FRAME_RANGE:
+ case EXPR_KIND_WINDOW_FRAME_ROWS:
+ case EXPR_KIND_WINDOW_FRAME_GROUPS:
+ case EXPR_KIND_SELECT_TARGET:
+ case EXPR_KIND_INSERT_TARGET:
+ case EXPR_KIND_UPDATE_SOURCE:
+ case EXPR_KIND_UPDATE_TARGET:
+ case EXPR_KIND_MERGE_WHEN:
+ case EXPR_KIND_MERGE_RETURNING:
+ case EXPR_KIND_GROUP_BY:
+ case EXPR_KIND_ORDER_BY:
+ case EXPR_KIND_DISTINCT_ON:
+ case EXPR_KIND_LIMIT:
+ case EXPR_KIND_OFFSET:
+ case EXPR_KIND_RETURNING:
+ case EXPR_KIND_VALUES:
+ case EXPR_KIND_VALUES_SINGLE:
+ case EXPR_KIND_ALTER_COL_TRANSFORM:
+ case EXPR_KIND_EXECUTE_PARAMETER:
+ case EXPR_KIND_POLICY:
+ case EXPR_KIND_CALL_ARGUMENT:
+ case EXPR_KIND_COPY_WHERE:
+ case EXPR_KIND_LET_TARGET:
+ result = true;
+ break;
+
+ /* session variables not allowed */
+ case EXPR_KIND_CHECK_CONSTRAINT:
+ case EXPR_KIND_DOMAIN_CHECK:
+ case EXPR_KIND_COLUMN_DEFAULT:
+ case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_INDEX_EXPRESSION:
+ case EXPR_KIND_INDEX_PREDICATE:
+ case EXPR_KIND_STATS_EXPRESSION:
+ case EXPR_KIND_TRIGGER_WHEN:
+ case EXPR_KIND_PARTITION_BOUND:
+ case EXPR_KIND_PARTITION_EXPRESSION:
+ case EXPR_KIND_GENERATED_COLUMN:
+ case EXPR_KIND_JOIN_USING:
+ case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ result = false;
+ break;
+ }
+
+ return result;
+}
+
/*
* Transform a ColumnRef.
*
@@ -575,6 +664,8 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
case EXPR_KIND_COPY_WHERE:
case EXPR_KIND_GENERATED_COLUMN:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
@@ -847,8 +938,61 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
}
/*
- * Throw error if no translation found.
+ * There are contexts where session variables are not allowed. We don't
+ * need to identify session variables in such a context, but identifying
+ * them allows us to raise meaningful error messages like "you cannot use
+ * session variables here".
*/
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind))
+ {
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* -----
+ * Session variables are shadowed by columns, routine variables or
+ * routine arguments. We certainly don't want to use a session variable
+ * when it is exactly shadowed, but a RTE like this is conceivable:
+ *
+ * CREATE TYPE t AS (c int);
+ * CREATE VARIABLE foo AS t;
+ * CREATE TABLE foo(a int, b int);
+ *
+ * SELECT foo.a, foo.b, foo.c FROM foo;
+ *
+ * However, that is very confusing, so we disallow it. We don't try to
+ * identify a variable if we know that it would be shadowed.
+ * -----
+ */
+ if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ {
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(cref->fields)),
+ parser_errposition(pstate, cref->location)));
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ node = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, cref->location);
+ }
+ }
+ }
+
+ /* throw an error if no translation was found */
if (node == NULL)
{
switch (crerr)
@@ -880,6 +1024,75 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
return node;
}
+/*
+ * Generate param variable for reference to session variable
+ */
+static Node *
+makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location)
+{
+ Param *param;
+
+ param = makeNode(Param);
+
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+ param->paramcollid = collid;
+
+ pstate->p_hasSessionVariables = true;
+
+ if (attrname != NULL)
+ {
+ TupleDesc tupdesc;
+ int i;
+
+ tupdesc = lookup_rowtype_tupdesc_noerror(typid, typmod, true);
+ if (!tupdesc)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("variable \"%s.%s\" is of type \"%s\", which is not a composite type",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, location)));
+
+ for (i = 0; i < tupdesc->natts; i++)
+ {
+ Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+ if (strcmp(attrname, NameStr(att->attname)) == 0 &&
+ !att->attisdropped)
+ {
+ /* success, so generate a FieldSelect expression */
+ FieldSelect *fselect = makeNode(FieldSelect);
+
+ fselect->arg = (Expr *) param;
+ fselect->fieldnum = i + 1;
+ fselect->resulttype = att->atttypid;
+ fselect->resulttypmod = att->atttypmod;
+ /* save attribute's collation for parse_collate.c */
+ fselect->resultcollid = att->attcollation;
+
+ ReleaseTupleDesc(tupdesc);
+ return (Node *) fselect;
+ }
+ }
+
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_COLUMN),
+ errmsg("could not identify column \"%s\" in variable \"%s.%s\"",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ parser_errposition(pstate, location)));
+ }
+
+ return (Node *) param;
+}
+
static Node *
transformParamRef(ParseState *pstate, ParamRef *pref)
{
@@ -1815,6 +2028,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_VALUES:
case EXPR_KIND_VALUES_SINGLE:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
case EXPR_KIND_CHECK_CONSTRAINT:
@@ -1858,6 +2072,9 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_GENERATED_COLUMN:
err = _("cannot use subquery in column generation expression");
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ err = _("cannot use subquery as target of assign statement");
+ break;
/*
* There is intentionally no default: case here, so that the
@@ -3207,6 +3424,10 @@ ParseExprKindName(ParseExprKind exprKind)
return "GENERATED AS";
case EXPR_KIND_CYCLE_MARK:
return "CYCLE";
+ case EXPR_KIND_ASSIGN_TARGET:
+ return "ASSIGN";
+ case EXPR_KIND_LET_TARGET:
+ return "LET";
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index 583bbbf232f..dc25f6dcd0e 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2656,6 +2656,8 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location)
err = _("set-returning functions are not allowed in column generation expressions");
break;
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
errkind = true;
break;
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
index 51d7703eff7..244efcddf32 100644
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -405,6 +405,7 @@ transformMergeStmt(ParseState *pstate, MergeStmt *stmt)
qry->hasTargetSRFs = false;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c
index b44f9072280..446c71953bf 100644
--- a/src/backend/tcop/dest.c
+++ b/src/backend/tcop/dest.c
@@ -38,6 +38,7 @@
#include "executor/functions.h"
#include "executor/tqueue.h"
#include "executor/tstoreReceiver.h"
+#include "executor/svariableReceiver.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
@@ -155,6 +156,9 @@ CreateDestReceiver(CommandDest dest)
case DestExplainSerialize:
return CreateExplainSerializeDestReceiver(NULL);
+
+ case DestVariable:
+ return CreateVariableDestReceiver(InvalidOid);
}
/* should never get here */
@@ -191,6 +195,7 @@ EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_o
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -237,6 +242,7 @@ NullCommand(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -281,6 +287,7 @@ ReadyForQuery(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 99a51877d34..7a508a3644f 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -49,6 +49,7 @@
#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
+#include "commands/session_variable.h"
#include "commands/subscriptioncmds.h"
#include "commands/tablecmds.h"
#include "commands/tablespace.h"
@@ -235,6 +236,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CallStmt:
case T_DoStmt:
+ case T_LetStmt:
{
/*
* Commands inside the DO block or the called procedure might
@@ -1067,6 +1069,11 @@ standard_ProcessUtility(PlannedStmt *pstmt,
break;
}
+ case T_LetStmt:
+ ExecuteLetStmt(pstate, (LetStmt *) parsetree, params,
+ queryEnv, qc);
+ break;
+
default:
/* All other statement types have event trigger support */
ProcessUtilitySlow(pstate, pstmt, queryString,
@@ -2206,6 +2213,10 @@ UtilityContainsQuery(Node *parsetree)
return UtilityContainsQuery(qry->utilityStmt);
return qry;
+ case T_LetStmt:
+ qry = castNode(Query, ((LetStmt *) parsetree)->query);
+ return qry;
+
default:
return NULL;
}
@@ -2404,6 +2415,10 @@ CreateCommandTag(Node *parsetree)
tag = CMDTAG_SELECT;
break;
+ case T_LetStmt:
+ tag = CMDTAG_LET;
+ break;
+
/* utility statements --- same whether raw or cooked */
case T_TransactionStmt:
{
@@ -3289,6 +3304,7 @@ GetCommandLogLevel(Node *parsetree)
break;
case T_PLAssignStmt:
+ case T_LetStmt:
lev = LOGSTMT_ALL;
break;
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 54dad975553..7417054c38f 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -37,6 +37,7 @@
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablespace.h"
#include "common/keywords.h"
@@ -531,6 +532,7 @@ static char *generate_function_name(Oid funcid, int nargs,
static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2);
static void add_cast_to(StringInfo buf, Oid typid);
static char *generate_qualified_type_name(Oid typid);
+static char *generate_session_variable_name(Oid varid);
static text *string_to_text(char *str);
static char *flatten_reloptions(Oid relid);
static void get_reloptions(StringInfo buf, Datum reloptions);
@@ -8677,6 +8679,14 @@ get_parameter(Param *param, deparse_context *context)
return;
}
+ /* translate paramvarid to session variable name */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ return;
+ }
+
/*
* Alternatively, maybe it's a subplan output, which we print as a
* reference to the subplan. (We could drill down into the subplan and
@@ -13477,6 +13487,42 @@ generate_collation_name(Oid collid)
return result;
}
+/*
+ * generate_session_variable_name
+ * Compute the name to display for a session variable specified by OID
+ *
+ * The result includes all necessary quoting and schema-prefixing.
+ */
+static char *
+generate_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+ char *nspname;
+ char *result;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = NameStr(varform->varname);
+
+ if (!VariableIsVisible(varid))
+ nspname = get_namespace_name_or_temp(varform->varnamespace);
+ else
+ nspname = NULL;
+
+ result = quote_qualified_identifier(nspname, varname);
+
+ ReleaseSysCache(tup);
+
+ return result;
+}
+
/*
* Given a C string, produce a TEXT datum.
*
diff --git a/src/backend/utils/cache/plancache.c b/src/backend/utils/cache/plancache.c
index 55db8f53705..632c438a7bd 100644
--- a/src/backend/utils/cache/plancache.c
+++ b/src/backend/utils/cache/plancache.c
@@ -58,6 +58,7 @@
#include "access/transam.h"
#include "catalog/namespace.h"
+#include "catalog/pg_variable.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
@@ -162,6 +163,7 @@ InitPlanCache(void)
CacheRegisterSyscacheCallback(AMOPOPID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNSERVEROID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNDATAWRAPPEROID, PlanCacheSysCallback, (Datum) 0);
+ CacheRegisterSyscacheCallback(VARIABLEOID, PlanCacheObjectCallback, (Datum) 0);
}
/*
@@ -1903,17 +1905,32 @@ ScanQueryForLocks(Query *parsetree, bool acquire)
/*
* Recurse into sublink subqueries, too. But we already did the ones in
- * the rtable and cteList.
+ * the rtable and cteList. We need to force a recursive call for session
+ * variables too, to find and lock variables used in the query (see
+ * ScanQueryWalker).
*/
- if (parsetree->hasSubLinks)
+ if (parsetree->hasSubLinks ||
+ parsetree->hasSessionVariables)
{
query_tree_walker(parsetree, ScanQueryWalker, &acquire,
QTW_IGNORE_RC_SUBQUERIES);
}
+
+ /* process session variables */
+ if (OidIsValid(parsetree->resultVariable))
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ }
}
/*
- * Walker to find sublink subqueries for ScanQueryForLocks
+ * Walker to find sublink subqueries or referenced session variables
+ * for ScanQueryForLocks
*/
static bool
ScanQueryWalker(Node *node, bool *acquire)
@@ -1928,6 +1945,20 @@ ScanQueryWalker(Node *node, bool *acquire)
ScanQueryForLocks(castNode(Query, sub->subselect), *acquire);
/* Fall through to process lefthand args of SubLink */
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ }
+ }
/*
* Do NOT recurse into Query nodes, because ScanQueryForLocks already
@@ -2058,7 +2089,9 @@ PlanCacheRelCallback(Datum arg, Oid relid)
/*
* PlanCacheObjectCallback
- * Syscache inval callback function for PROCOID and TYPEOID caches
+ * Syscache inval callback function for TYPEOID, PROCOID, NAMESPACEOID,
+ * OPEROID, AMOPOPID, FOREIGNSERVEROID, FOREIGNDATAWRAPPEROID and
+ * VARIABLEOID caches.
*
* Invalidate all plans mentioning the object with the specified hash value,
* or all plans mentioning any member of this cache if hashvalue == 0.
diff --git a/src/backend/utils/fmgr/fmgr.c b/src/backend/utils/fmgr/fmgr.c
index 782291d9998..093622fbdc4 100644
--- a/src/backend/utils/fmgr/fmgr.c
+++ b/src/backend/utils/fmgr/fmgr.c
@@ -2026,9 +2026,13 @@ get_call_expr_arg_stable(Node *expr, int argnum)
*/
if (IsA(arg, Const))
return true;
- if (IsA(arg, Param) &&
- ((Param *) arg)->paramkind == PARAM_EXTERN)
- return true;
+ if (IsA(arg, Param))
+ {
+ Param *p = (Param *) arg;
+
+ if (p->paramkind == PARAM_EXTERN || p->paramkind == PARAM_VARIABLE)
+ return true;
+ }
return false;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index c6a1bb09f3f..57364ea6a1c 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1214,8 +1214,8 @@ static const char *const sql_commands[] = {
"ABORT", "ALTER", "ANALYZE", "BEGIN", "CALL", "CHECKPOINT", "CLOSE", "CLUSTER",
"COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE",
"DELETE FROM", "DISCARD", "DO", "DROP", "END", "EXECUTE", "EXPLAIN",
- "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LISTEN", "LOAD", "LOCK",
- "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
+ "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LET",
+ "LISTEN", "LOAD", "LOCK", "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
"REASSIGN", "REFRESH MATERIALIZED VIEW", "REINDEX", "RELEASE",
"RESET", "REVOKE", "ROLLBACK",
"SAVEPOINT", "SECURITY LABEL", "SELECT", "SET", "SHOW", "START",
@@ -4664,6 +4664,14 @@ match_previous_words(int pattern_id,
else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES"))
COMPLETE_WITH("(");
+/* LET */
+ /* If prev. word is LET suggest a list of variables */
+ else if (Matches("LET"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ /* Complete LET <variable> with "=" */
+ else if (TailMatches("LET", MatchAny))
+ COMPLETE_WITH("=");
+
/* LOCK */
/* Complete LOCK [TABLE] [ONLY] with a list of tables */
else if (Matches("LOCK"))
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index bdac0c13bec..5060b8c9490 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -174,6 +174,7 @@ extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
extern List *NamesFromList(List *names);
extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+extern Oid IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror);
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 3d3c6eb24b5..5b45be5afaf 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -18,6 +18,7 @@
#ifndef PG_VARIABLE_H
#define PG_VARIABLE_H
+#include "access/xlogdefs.h"
#include "catalog/genbki.h"
#include "catalog/objectaddress.h"
#include "catalog/pg_variable_d.h"
@@ -35,6 +36,14 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* OID of entry in pg_type for variable's type */
Oid vartype BKI_LOOKUP(pg_type);
+ /*
+ * Used for identity check [oid, create_lsn].
+ *
+ * This column of the 8-byte XlogRecPtr type should be at an address that
+ * is divisible by 8, but before any column of type NameData.
+ */
+ XLogRecPtr varcreate_lsn;
+
/* variable name */
NameData varname;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
new file mode 100644
index 00000000000..2391b9ad443
--- /dev/null
+++ b/src/include/commands/session_variable.h
@@ -0,0 +1,30 @@
+/*-------------------------------------------------------------------------
+ *
+ * sessionvariable.h
+ * prototypes for sessionvariable.c.
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/commands/session_variable.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SESSIONVARIABLE_H
+#define SESSIONVARIABLE_H
+
+#include "nodes/params.h"
+#include "nodes/parsenodes.h"
+#include "parser/parse_node.h"
+#include "tcop/cmdtag.h"
+#include "utils/queryenvironment.h"
+
+extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
+extern Datum GetSessionVariable(Oid varid, bool *isNull);
+
+extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
+ QueryEnvironment *queryEnv, QueryCompletion *qc);
+
+#endif
diff --git a/src/include/executor/svariableReceiver.h b/src/include/executor/svariableReceiver.h
new file mode 100644
index 00000000000..db44d8b94c6
--- /dev/null
+++ b/src/include/executor/svariableReceiver.h
@@ -0,0 +1,22 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.h
+ * prototypes for svariableReceiver.c
+ *
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/executor/svariableReceiver.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SVARIABLE_RECEIVER_H
+#define SVARIABLE_RECEIVER_H
+
+#include "tcop/dest.h"
+
+extern DestReceiver *CreateVariableDestReceiver(Oid varid);
+
+#endif /* SVARIABLE_RECEIVER_H */
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index e2d1dc1e067..91051681d3b 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -635,6 +635,16 @@ typedef struct AsyncRequest
* tuples) */
} AsyncRequest;
+/* ----------------
+ * SessionVariableValue
+ * ----------------
+ */
+typedef struct SessionVariableValue
+{
+ bool isnull;
+ Datum value;
+} SessionVariableValue;
+
/* ----------------
* EState information
*
@@ -694,6 +704,10 @@ typedef struct EState
ParamListInfo es_param_list_info; /* values of external params */
ParamExecData *es_param_exec_vals; /* values of internal params */
+ /* Session variables info: */
+ int es_num_session_variables; /* number of used variables */
+ SessionVariableValue *es_session_variables; /* array of copies of values */
+
QueryEnvironment *es_queryEnv; /* query environment */
/* Other working state: */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index b07c42f94d0..b1e9efa6979 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -142,6 +142,9 @@ typedef struct Query
*/
int resultRelation pg_node_attr(query_jumble_ignore);
+ /* target variable of LET statement */
+ Oid resultVariable;
+
/* has aggregates in tlist or havingQual */
bool hasAggs pg_node_attr(query_jumble_ignore);
/* has window functions in tlist */
@@ -162,6 +165,8 @@ typedef struct Query
bool hasRowSecurity pg_node_attr(query_jumble_ignore);
/* parser has added an RTE_GROUP RTE */
bool hasGroupRTE pg_node_attr(query_jumble_ignore);
+ /* uses session variables */
+ bool hasSessionVariables pg_node_attr(query_jumble_ignore);
/* is a RETURN statement */
bool isReturn pg_node_attr(query_jumble_ignore);
@@ -2144,6 +2149,18 @@ typedef struct MergeStmt
ParseLoc stmt_len; /* length in bytes; 0 means "rest of string" */
} MergeStmt;
+/* ----------------------
+ * Let Statement
+ * ----------------------
+ */
+typedef struct LetStmt
+{
+ NodeTag type;
+ List *target; /* target variable */
+ Node *query; /* source expression */
+ ParseLoc location;
+} LetStmt;
+
/* ----------------------
* Select Statement
*
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index 00c700cc3e7..9667c1df416 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -179,6 +179,18 @@ typedef struct PlannerGlobal
/* partition descriptors */
PartitionDirectory partition_directory pg_node_attr(read_write_ignore);
+
+ /* list of used session variables */
+ List *sessionVariables;
+
+ /* Oid of session variable used like target of LET command */
+ Oid resultVariable;
+
+ /* oid of session variable used like base node for assignment indirection */
+ Oid basenodeSessionVarid;
+
+ /* true, if we do SELECT permission check on basenodeSessionVarid */
+ bool basenodeSessionVarSelectCheck;
} PlannerGlobal;
/* macro for fetching the Plan associated with a SubPlan node */
@@ -524,6 +536,8 @@ struct PlannerInfo
bool placeholdersFrozen;
/* true if planning a recursive WITH item */
bool hasRecursion;
+ /* true if session variables were used */
+ bool hasSessionVariables;
/*
* The rangetable index for the RTE_GROUP RTE, or 0 if there is no
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index bf1f25c0dba..1f739dc6140 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -128,6 +128,15 @@ typedef struct PlannedStmt
/* non-null if this is utility stmt */
Node *utilityStmt;
+ List *sessionVariables; /* OIDs for PARAM_VARIABLE Params */
+
+ /*
+ * The oid of session variable execluded from permission check.
+ * This session variable is used as base node of assignment indirection
+ * (and it is used only there).
+ */
+ int exclSelectPermCheckVarid;
+
/* statement location in source string (copied from Query) */
/* start location, or -1 if unknown */
ParseLoc stmt_location;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 839e71d52f4..2fa9b1bcd04 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -378,6 +378,9 @@ typedef struct Const
* of the `paramid' field contain the SubLink's subLinkId, and
* the low-order 16 bits contain the column number. (This type
* of Param is also converted to PARAM_EXEC during planning.)
+ *
+ * PARAM_VARIABLE: The parameter is a reference to a session variable
+ * (paramvarid holds the variable's OID).
*/
typedef enum ParamKind
{
@@ -385,6 +388,7 @@ typedef enum ParamKind
PARAM_EXEC,
PARAM_SUBLINK,
PARAM_MULTIEXPR,
+ PARAM_VARIABLE,
} ParamKind;
typedef struct Param
@@ -397,6 +401,16 @@ typedef struct Param
int32 paramtypmod pg_node_attr(query_jumble_ignore);
/* OID of collation, or InvalidOid if none */
Oid paramcollid pg_node_attr(query_jumble_ignore);
+ /* OID of session variable if it is used */
+ Oid paramvarid pg_node_attr(query_jumble_ignore);
+
+ /*
+ * true if param is used as base node of assignment indirection
+ * (when target of LET statement is an array field or an record field).
+ * For this param we do not check SELECT access right, because this
+ * param is used just for execution of UPDATE operation.
+ */
+ bool parambasenode;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index fee3378bbe3..e8551320d14 100644
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -125,4 +125,6 @@ extern void record_plan_function_dependency(PlannerInfo *root, Oid funcid);
extern void record_plan_type_dependency(PlannerInfo *root, Oid typid);
extern bool extract_query_dependencies_walker(Node *node, PlannerInfo *context);
+extern void pull_up_has_session_variables(PlannerInfo *root);
+
#endif /* PLANMAIN_H */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 793ace526df..431167f6b43 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -257,6 +257,7 @@ PG_KEYWORD("leading", LEADING, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("leakproof", LEAKPROOF, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("least", LEAST, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("left", LEFT, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("let", LET, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("level", LEVEL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("like", LIKE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("limit", LIMIT, RESERVED_KEYWORD, AS_LABEL)
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 994284019fb..0b7b69a4159 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -82,6 +82,8 @@ typedef enum ParseExprKind
EXPR_KIND_COPY_WHERE, /* WHERE condition in COPY FROM */
EXPR_KIND_GENERATED_COLUMN, /* generation expression for a column */
EXPR_KIND_CYCLE_MARK, /* cycle mark value */
+ EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */
+ EXPR_KIND_LET_TARGET, /* LET target */
} ParseExprKind;
@@ -244,6 +246,7 @@ struct ParseState
bool p_hasTargetSRFs;
bool p_hasSubLinks;
bool p_hasModifyingCTE;
+ bool p_hasSessionVariables;
Node *p_last_srf; /* most recent set-returning func/op found */
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index ea86954dded..22082c30008 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -186,6 +186,7 @@ PG_CMDTAG(CMDTAG_GRANT, "GRANT", true, false, false)
PG_CMDTAG(CMDTAG_GRANT_ROLE, "GRANT ROLE", false, false, false)
PG_CMDTAG(CMDTAG_IMPORT_FOREIGN_SCHEMA, "IMPORT FOREIGN SCHEMA", true, false, false)
PG_CMDTAG(CMDTAG_INSERT, "INSERT", false, false, true)
+PG_CMDTAG(CMDTAG_LET, "LET", false, false, false)
PG_CMDTAG(CMDTAG_LISTEN, "LISTEN", false, false, false)
PG_CMDTAG(CMDTAG_LOAD, "LOAD", false, false, false)
PG_CMDTAG(CMDTAG_LOCK_TABLE, "LOCK TABLE", false, false, false)
diff --git a/src/include/tcop/dest.h b/src/include/tcop/dest.h
index 00c092e3d7c..6ce3ea0e617 100644
--- a/src/include/tcop/dest.h
+++ b/src/include/tcop/dest.h
@@ -97,6 +97,7 @@ typedef enum
DestTransientRel, /* results sent to transient relation */
DestTupleQueue, /* results sent to tuple queue */
DestExplainSerialize, /* results are serialized and discarded */
+ DestVariable, /* results sent to session variable */
} CommandDest;
/* ----------------
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index d4377ceecbf..cb282404c1a 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8264,7 +8264,8 @@ exec_is_simple_query(PLpgSQL_expr *expr)
query->sortClause ||
query->limitOffset ||
query->limitCount ||
- query->setOperations)
+ query->setOperations ||
+ query->hasSessionVariables)
return false;
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index c36660ce6d3..f22467186e3 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -431,3 +431,1235 @@ DROP VARIABLE public.var1;
DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+-- check access rights
+CREATE ROLE regress_noowner;
+CREATE VARIABLE var1 AS int;
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+-- should fail
+SET ROLE TO regress_noowner;
+SELECT var1;
+ERROR: permission denied for session variable var1
+SELECT sqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: SQL function "sqlfx" statement 1
+SELECT plpgsqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "$1 + var1"
+PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
+-- should be ok
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+-- should be ok
+SET ROLE TO regress_noowner;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+DROP ROLE regress_noowner;
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- start a new session
+\c
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- should fail, dependency
+DROP VARIABLE var1;
+ERROR: cannot drop session variable var1 because other objects depend on it
+DETAIL: view test_view depends on session variable var1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+NOTICE: drop cascades to view test_view
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+LET var1 = 'str1';
+LET var2 = 'str2';
+SELECT sqlfx1(sqlfx2('Hello'));
+ sqlfx1
+-------------------
+ str1, str2, Hello
+(1 row)
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+ QUERY PLAN
+------------------------------------------------------
+ Result
+ Output: sqlfx1(sqlfx2('Hello'::character varying))
+(2 rows)
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+SET plan_cache_mode TO force_generic_plan;
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 3.14
+(1 row)
+
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 6.28
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 9.42
+(1 row)
+
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 12.56
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+ERROR: function plpgsqlfx2() does not exist
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+SET plan_cache_mode TO DEFAULT;
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 1
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 55
+DROP VARIABLE var1;
+DROP TABLE testvar;
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+NOTICE: result array: {1,2,3,4,5,6,7,8,9,10}
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+-- should not crash (but is not supported yet)
+CALL p(v);
+ERROR: session variable cannot be used as an argument
+DO $$ BEGIN CALL p(v); END $$;
+ERROR: session variable cannot be used as an argument
+CONTEXT: SQL statement "CALL p(v)"
+PL/pgSQL function inline_code_block line 1 at CALL
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+-- should fail
+EXECUTE ptest(v);
+ERROR: session variable cannot be used as an argument
+DEALLOCATE ptest;
+DROP VARIABLE v;
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+-- should fail
+LET var1 = pi();
+ERROR: session variable "var1" doesn't exist
+LINE 1: LET var1 = pi();
+ ^
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+ var1
+------------------
+ 3.14159265358979
+(1 row)
+
+SET search_path TO svartest;
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+ var1
+------------------
+ 13.1415926535898
+(1 row)
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to session variable svartest.var1
+CREATE VARIABLE var1 AS text;
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+SELECT var1;
+ var1
+-------
+ hello
+(1 row)
+
+DROP VARIABLE var1;
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+-- should fail
+SELECT var1;
+ERROR: domain int_domain does not allow null values
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+ var1
+------
+ 1000
+(1 row)
+
+-- should fail
+LET var1 = 10;
+ERROR: value for domain int_domain violates check constraint "int_domain_check"
+-- should fail
+LET var1 = NULL;
+ERROR: domain int_domain does not allow null values
+-- note - domain defaults are not supported yet (like PLpgSQL)
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+ var1
+----------------------------------------
+ {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+(1 row)
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+DROP VARIABLE var1;
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+ var1
+------
+ 100
+(1 row)
+
+SET search_path to public, svartest;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table foo
+drop cascades to session variable var1
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+LET var2[var1] = 0;
+SELECT var2;
+ var2
+-----------
+ [2:2]={0}
+(1 row)
+
+DROP VARIABLE var1, var2;
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+SELECT var2;
+ var2
+------
+ {}
+(1 row)
+
+DROP VARIABLE var1, var2;
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+ERROR: syntax error at or near "LET"
+LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x;
+ ^
+-- should be ok
+LET var1 = generate_series(1, 1);
+-- should fail
+LET var1 = generate_series(1, 2);
+ERROR: expression returned more than one row
+LET var1 = generate_series(1, 0);
+ERROR: expression returned no rows
+DROP VARIABLE var1;
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+SELECT v1;
+ v1
+------------
+ (1,2,3.00)
+(1 row)
+
+SELECT v2;
+ v2
+---------------
+ (10,20,31.40)
+(1 row)
+
+SELECT (v1).*;
+ x | y | z
+---+---+------
+ 1 | 2 | 3.00
+(1 row)
+
+SELECT (v2).*;
+ x | y | z
+----+----+-------
+ 10 | 20 | 31.40
+(1 row)
+
+SELECT v1.x + v1.z;
+ ?column?
+----------
+ 4.00
+(1 row)
+
+SELECT v2.x + v2.z;
+ ?column?
+----------
+ 41.40
+(1 row)
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail
+SELECT v2.x;
+ERROR: permission denied for session variable v2
+SET ROLE TO DEFAULT;
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+ERROR: improper qualified name (too many dotted names): nodb.noschema.novar.nofield.nosubfield
+LET nodb.noschema.novar.nofield = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar.nofield
+LET nodb.noschema.novar = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar
+CREATE TYPE t1 AS (a int, b numeric, c text);
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+ v1
+----------------------------
+ (1,3.14159265358979,hello)
+(1 row)
+
+LET v1.b = 10.2222;
+SELECT v1;
+ v1
+-------------------
+ (1,10.2222,hello)
+(1 row)
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1
+LINE 1: LET v1.x = 10;
+ ^
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+ERROR: assignment expression returned 3 columns
+LINE 1: LET v1 = (NULL::t1).*;
+ ^
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+ v1
+-------------
+ (1,10.2222)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+ v1
+--------------
+ (1,10.2222,)
+(1 row)
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+ v1
+--------------
+ (10,10.3,20)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+ v1
+---------
+ (10,20)
+(1 row)
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+ERROR: cannot alter type "t1" because session variable "public.v1" uses it
+DROP VARIABLE v1;
+DROP TYPE t1;
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+ var1
+----------------------------------
+ (10,3.14159265358979,05-26-2023)
+(1 row)
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+ERROR: cannot alter table "svar_test" because session variable "public.var1" uses it
+-- should fail
+DROP TABLE svar_test;
+ERROR: cannot drop table svar_test because other objects depend on it
+DETAIL: session variable var1 depends on type svar_test
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+CREATE ROLE regress_var_test_role;
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+-- should fail
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+SELECT var1.a;
+ a
+------
+ 1000
+(1 row)
+
+SELECT var1;
+ var1
+------------
+ (1000,100)
+(1 row)
+
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+NOTICE: (0,100)
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+NOTICE: 0
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail again
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+-- should fail
+SELECT var1.a;
+ERROR: variable "public.var1" is of type "text", which is not a composite type
+LINE 1: SELECT var1.a;
+ ^
+SELECT var2.c;
+ERROR: could not identify column "c" in variable "public.var2"
+LINE 1: SELECT var2.c;
+ ^
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+-- should fail
+LET var1 = '1'::jsonb;
+ERROR: variable "public.var1" is of type integer, but expression is of type jsonb
+LINE 1: LET var1 = '1'::jsonb;
+ ^
+HINT: You will need to rewrite or cast the expression.
+-- should be ok
+LET var1 = '1'::jsonb::int;
+-- should fail
+LET var1.x = 10;
+ERROR: cannot assign to field "x" of session variable "public.var1" because its type integer is not a composite type
+LINE 1: LET var1.x = 10;
+ ^
+DROP VARIABLE var1;
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+-- should fail
+LET vartest.vartest = 1;
+ERROR: target "vartest.vartest" of LET command is ambiguous
+LINE 1: LET vartest.vartest = 1;
+ ^
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+ERROR: type "vartesttype" does not exist
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+ var1
+------------
+ {10.1,2.1}
+(1 row)
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+ERROR: set-returning functions are not allowed in LET
+LINE 1: LET var1[generate_series(1,3)] = 100;
+ ^
+DROP VARIABLE var1;
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+ var1
+--------------------
+ (10.2,"{0.0,0.0}")
+(1 row)
+
+LET var1.b[1] = 10.3;
+SELECT var1;
+ var1
+---------------------
+ (10.2,"{10.3,0.0}")
+(1 row)
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ count
+-------
+ 100
+(1 row)
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ QUERY PLAN
+-----------------------------------
+ Aggregate
+ -> Seq Scan on svar_test
+ Filter: ((a % 10) = zero)
+(3 rows)
+
+LET zero = (SELECT count(*) FROM svar_test);
+-- result should be 1000
+SELECT zero;
+ zero
+------
+ 1000
+(1 row)
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO on;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO off;
+DROP VIEW var1view;
+DROP VARIABLE var1;
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 100
+(1 row)
+
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 200
+(1 row)
+
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+---
+(0 rows)
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+ relname
+----------
+ pg_class
+(1 row)
+
+DROP VARIABLE var1;
+CREATE TABLE xxtab(avar int);
+INSERT INTO xxtab VALUES(333);
+CREATE TYPE xxtype AS (avar int);
+CREATE VARIABLE xxtab AS xxtype;
+INSERT INTO xxtab VALUES(10);
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+CREATE VARIABLE public.avar AS int;
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+ avar
+------
+
+
+(2 rows)
+
+DROP VARIABLE xxtab;
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+DROP VARIABLE public.avar;
+DROP TYPE xxtype;
+DROP TABLE xxtab;
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+CREATE TABLE public.svar(a int, b int);
+INSERT INTO public.svar VALUES(10, 20);
+LET public.svar = (100, 200, 300);
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT var1.* FROM vartest_foo;
+ ^
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+ a | b
+----+----
+ 10 | 20
+ 30 | 40
+(2 rows)
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT count(var1.*) FROM vartest_foo;
+ ^
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+ count
+-------
+ 2
+(1 row)
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table vartest.vartest_foo
+drop cascades to session variable vartest.var1
+CREATE TYPE ab AS (a integer, b integer);
+CREATE VARIABLE v_ab AS ab;
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+CREATE SCHEMA v_ab;
+CREATE VARIABLE v_ab.a AS integer;
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+SET search_path TO public;
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+-- should be ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+-- should be still ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+ERROR: session variable reference "xxx_am.b" is ambiguous
+LINE 1: SELECT xxx_am.b;
+ ^
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+ b
+----
+ 10
+(1 row)
+
+SELECT :"DBNAME".xxx_am.b;
+ b
+----
+ 20
+(1 row)
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+ b
+----
+ 10
+(1 row)
+
+SELECT x.b FROM xxx_am x;
+ b
+----
+ 10
+(1 row)
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+CREATE SCHEMA :"DBNAME";
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+SET search_path TO :"DBNAME";
+-- should be ambiguous
+SELECT :"DBNAME".b;
+ERROR: session variable reference "regression.b" is ambiguous
+LINE 1: SELECT "regression".b;
+ ^
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+ERROR: session variable reference "regression.regression.b" is ambiguous
+LINE 1: SELECT "regression"."regression".b;
+ ^
+CREATE TABLE :"DBNAME"(b int);
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+ b
+---
+(0 rows)
+
+DROP TABLE :"DBNAME";
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+RESET search_path;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index eeb0f94ca3c..e72360d5254 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -295,3 +295,886 @@ DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+
+-- check access rights
+CREATE ROLE regress_noowner;
+
+CREATE VARIABLE var1 AS int;
+
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+SELECT sqlfx(20);
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx(20);
+SELECT plpgsqlfx_sd(20);
+
+-- should fail
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+-- should be ok
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx_sd(20);
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+
+-- should be ok
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+
+DROP ROLE regress_noowner;
+
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- start a new session
+\c
+
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- should fail, dependency
+DROP VARIABLE var1;
+
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+
+LET var1 = 'str1';
+LET var2 = 'str2';
+
+SELECT sqlfx1(sqlfx2('Hello'));
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+
+SET plan_cache_mode TO force_generic_plan;
+
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+
+SET plan_cache_mode TO DEFAULT;
+
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP TABLE testvar;
+
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+
+-- should not crash (but is not supported yet)
+CALL p(v);
+
+DO $$ BEGIN CALL p(v); END $$;
+
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+
+-- should fail
+EXECUTE ptest(v);
+
+DEALLOCATE ptest;
+DROP VARIABLE v;
+
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+
+-- should fail
+LET var1 = pi();
+SELECT var1;
+
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+
+SET search_path TO svartest;
+
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS text;
+
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+
+-- should fail
+SELECT var1;
+
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+
+-- should fail
+LET var1 = 10;
+
+-- should fail
+LET var1 = NULL;
+
+-- note - domain defaults are not supported yet (like PLpgSQL)
+
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+
+SET search_path to public, svartest;
+
+SELECT var1;
+
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+LET var2[var1] = 0;
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+
+-- should be ok
+LET var1 = generate_series(1, 1);
+
+-- should fail
+LET var1 = generate_series(1, 2);
+LET var1 = generate_series(1, 0);
+
+DROP VARIABLE var1;
+
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+
+SELECT v1;
+SELECT v2;
+SELECT (v1).*;
+SELECT (v2).*;
+
+SELECT v1.x + v1.z;
+SELECT v2.x + v2.z;
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should fail
+SELECT v2.x;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+LET nodb.noschema.novar.nofield = 10;
+LET nodb.noschema.novar = 10;
+
+CREATE TYPE t1 AS (a int, b numeric, c text);
+
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+LET v1.b = 10.2222;
+SELECT v1;
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+
+DROP VARIABLE v1;
+DROP TYPE t1;
+
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+
+-- should fail
+DROP TABLE svar_test;
+
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+
+CREATE ROLE regress_var_test_role;
+
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+
+-- should fail
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should fail again
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+
+-- should fail
+SELECT var1.a;
+SELECT var2.c;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+
+CREATE VARIABLE var1 AS int;
+
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+
+-- should fail
+LET var1 = '1'::jsonb;
+
+-- should be ok
+LET var1 = '1'::jsonb::int;
+
+-- should fail
+LET var1.x = 10;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+
+-- should fail
+LET vartest.vartest = 1;
+
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+
+DROP VARIABLE var1;
+
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+LET var1.b[1] = 10.3;
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+LET zero = (SELECT count(*) FROM svar_test);
+
+-- result should be 1000
+SELECT zero;
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO on;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO off;
+
+DROP VIEW var1view;
+DROP VARIABLE var1;
+
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+
+DROP VARIABLE var1;
+
+CREATE TABLE xxtab(avar int);
+
+INSERT INTO xxtab VALUES(333);
+
+CREATE TYPE xxtype AS (avar int);
+
+CREATE VARIABLE xxtab AS xxtype;
+
+INSERT INTO xxtab VALUES(10);
+
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+
+-- should be ok
+SELECT avar FROM xxtab;
+
+CREATE VARIABLE public.avar AS int;
+
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+
+DROP VARIABLE xxtab;
+
+SELECT xxtab.avar FROM xxtab;
+
+DROP VARIABLE public.avar;
+
+DROP TYPE xxtype;
+
+DROP TABLE xxtab;
+
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+
+CREATE TABLE public.svar(a int, b int);
+
+INSERT INTO public.svar VALUES(10, 20);
+
+LET public.svar = (100, 200, 300);
+
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+
+CREATE TYPE ab AS (a integer, b integer);
+
+CREATE VARIABLE v_ab AS ab;
+
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+CREATE SCHEMA v_ab;
+
+CREATE VARIABLE v_ab.a AS integer;
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+
+SET search_path TO public;
+
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+
+-- should be ok
+SELECT xxx_am;
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+
+-- should be still ok
+SELECT xxx_am;
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+SELECT :"DBNAME".xxx_am.b;
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+SELECT x.b FROM xxx_am x;
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+
+CREATE SCHEMA :"DBNAME";
+
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+
+SET search_path TO :"DBNAME";
+
+-- should be ambiguous
+SELECT :"DBNAME".b;
+
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+
+CREATE TABLE :"DBNAME"(b int);
+
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+
+DROP TABLE :"DBNAME";
+
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+
+RESET search_path;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b2844730f79..95c7a892f97 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1504,6 +1504,7 @@ LargeObjectDesc
Latch
LauncherLastStartTimesEntry
LerpFunc
+LetStmt
LexDescr
LexemeEntry
LexemeHashKey
@@ -2619,6 +2620,7 @@ SerializedTransactionState
Session
SessionBackupState
SessionEndType
+SessionVariableValue
SetConstraintState
SetConstraintStateData
SetConstraintTriggerData
@@ -2813,6 +2815,9 @@ SupportRequestRows
SupportRequestSelectivity
SupportRequestSimplify
SupportRequestWFuncMonotonic
+SVariable
+SVariableData
+SVariableState
Syn
SyncOps
SyncRepConfigData
--
2.48.1
[text/x-patch] v20250216-0008-variable-fence-syntax-support-and-variable-fence-usa.patch (19.5K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/9-v20250216-0008-variable-fence-syntax-support-and-variable-fence-usa.patch)
download | inline diff:
From 2a8781fb212171fff2f20dae437a8a5e2b06aa70 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 19 Nov 2024 08:14:53 +0100
Subject: [PATCH 08/21] variable fence syntax support and variable fence usage
guard support
this patch introduces a concept of variable fence - syntax for variable
reference `VARIABLE(varname)` that is not in collision with column reference.
When variable fence usage guard warning is active, then usage variable
without variable fence in the case, where there can be column references,
the the warning is raised.
initial implementation of variable fence
---
doc/src/sgml/config.sgml | 65 ++++++++++++++++
doc/src/sgml/ddl.sgml | 15 ++++
src/backend/nodes/nodeFuncs.c | 6 ++
src/backend/parser/gram.y | 28 ++++++-
src/backend/parser/parse_expr.c | 74 ++++++++++++++++++-
src/backend/parser/parse_target.c | 7 ++
src/backend/utils/adt/ruleutils.c | 12 ++-
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/nodes/parsenodes.h | 10 +++
src/include/nodes/primnodes.h | 2 +
src/include/parser/parse_expr.h | 1 +
.../regress/expected/session_variables.out | 59 +++++++++++++++
src/test/regress/sql/session_variables.sql | 41 ++++++++++
14 files changed, 323 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 97f623f0498..a02f24e8a40 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11000,6 +11000,71 @@ DETAIL: Session variables can be shadowed by columns, routine's variables and r
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-use-fence-warning-guard" xreflabel="session_variables_use_fence_warning_guard">
+ <term><varname>session_variables_use_fence_warning_guard</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_use_fence_warning_guard</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when a session variable identifier is used
+ inside a query without variable fence. The default is <literal>off</literal>.
+ The warning is raised only when variable is used in places, where an
+ collisions with column names is possible.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE b int;
+LET b = 100;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_use_fence_warning_guard TO on;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "b" is not used inside variable fence
+LINE 1: SELECT a, b FROM foo;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SELECT a, VARIABLE(b) FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+ </para>
+
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. Unless another collision resolution technique is used
+ (dedicated schema or using prefixes like <literal>_</literal>),
+ the use of variable fence syntax is strongly recommended, and this
+ warning should be enabled.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 96912aaa436..4e8e7c6a42a 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5456,6 +5456,21 @@ SELECT name FROM foo;
<literal>schema.variable</literal>. It is strongly recommended to rename
shadowed variables or use qualified names always.
</para>
+
+ <para><firstterm>Variable fence</firstterm> is special syntax for session
+ variable identifier. Only name or qualified name can be used inside the
+ variable fence, and this name is used as only session variable identifier.
+<programlisting>
+SELECT VARIABLE(current_user_id);
+</programlisting>
+ </para>
+
+ <para>
+ When there is a risk of possible collisions between variable identifiers
+ and column names, then using variable fence syntax can be recommended.
+ Usage session variable without variable fence can be detected by
+ warning <xref linkend="guc-session-variables-use-fence-warning-guard"/>.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d8fc3d9fa69..575365eefcd 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1673,6 +1673,9 @@ exprLocation(const Node *expr)
case T_ParamRef:
loc = ((const ParamRef *) expr)->location;
break;
+ case T_VariableFence:
+ loc = ((const VariableFence *) expr)->location;
+ break;
case T_A_Const:
loc = ((const A_Const *) expr)->location;
break;
@@ -4715,6 +4718,9 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_VariableFence:
+ /* we assume the fields contain nothing interesting */
+ break;
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 77d9246f4a1..a8c098c3d5a 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -525,7 +525,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <node> def_arg columnElem where_clause where_or_current_clause
a_expr b_expr c_expr AexprConst indirection_el opt_slice_bound
columnref in_expr having_clause func_table xmltable array_expr
- OptWhereClause operator_def_arg
+ OptWhereClause operator_def_arg variable_fence
%type <list> opt_column_and_period_list
%type <list> rowsfrom_item rowsfrom_list opt_col_def_list
%type <boolean> opt_ordinality opt_without_overlaps
@@ -882,7 +882,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
*/
%nonassoc UNBOUNDED NESTED /* ideally would have same precedence as IDENT */
%nonassoc IDENT PARTITION RANGE ROWS GROUPS PRECEDING FOLLOWING CUBE ROLLUP
- SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH
+ SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH VARIABLE
%left Op OPERATOR /* multi-character ops and user-defined operators */
%left '+' '-'
%left '*' '/' '%'
@@ -15668,6 +15668,19 @@ c_expr: columnref { $$ = $1; }
else
$$ = $2;
}
+ | variable_fence opt_indirection
+ {
+ if ($2)
+ {
+ A_Indirection *n = makeNode(A_Indirection);
+
+ n->arg = (Node *) $1;
+ n->indirection = check_indirection($2, yyscanner);
+ $$ = (Node *) n;
+ }
+ else
+ $$ = $1;
+ }
| case_expr
{ $$ = $1; }
| func_expr
@@ -17054,6 +17067,17 @@ case_arg: a_expr { $$ = $1; }
| /*EMPTY*/ { $$ = NULL; }
;
+variable_fence:
+ VARIABLE '(' any_name ')'
+ {
+ VariableFence *vf = makeNode(VariableFence);
+
+ vf->varname = $3;
+ vf->location = @3;
+ $$ = (Node *) vf;
+ }
+ ;
+
columnref: ColId
{
$$ = makeColumnRef($1, NIL, @1, yyscanner);
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 63f1732f69e..dd03b1f14db 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -46,6 +46,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
bool session_variables_ambiguity_warning = false;
+bool session_variables_use_fence_warning_guard = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -81,6 +82,7 @@ static Node *transformWholeRowRef(ParseState *pstate,
static Node *transformIndirection(ParseState *pstate, A_Indirection *ind);
static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
static Node *transformCollateClause(ParseState *pstate, CollateClause *c);
+static Node *transformVariableFence(ParseState *pstate, VariableFence *vf);
static Node *transformJsonObjectConstructor(ParseState *pstate,
JsonObjectConstructor *ctor);
static Node *transformJsonArrayConstructor(ParseState *pstate,
@@ -112,7 +114,7 @@ static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
static Node *makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location);
+ char *attrname, bool fenced, int location);
/*
@@ -377,6 +379,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
result = transformJsonFuncExpr(pstate, (JsonFuncExpr *) expr);
break;
+ case T_VariableFence:
+ result = transformVariableFence(pstate, (VariableFence *) expr);
+ break;
+
default:
/* should not reach here */
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
@@ -1028,7 +1034,20 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
node = makeParamSessionVariable(pstate,
varid, typid, typmod, collid,
- attrname, cref->location);
+ attrname, false, cref->location);
+
+ /*
+ * The variable is not inside variable's fence, so raise warning
+ * when variable fence guard is active and the query has FROM
+ * clause.
+ */
+ if (session_variables_use_fence_warning_guard && pstate->p_rtable)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is not used inside variable fence",
+ NameListToString(cref->fields)),
+ errdetail("The collision of session variable' names and column names is possible."),
+ parser_errposition(pstate, cref->location)));
}
}
}
@@ -1071,7 +1090,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
static Node *
makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location)
+ char *attrname, bool fenced, int location)
{
Param *param;
@@ -1079,6 +1098,7 @@ makeParamSessionVariable(ParseState *pstate,
param->paramkind = PARAM_VARIABLE;
param->paramvarid = varid;
+ param->paramvarfenced = fenced;
param->paramtype = typid;
param->paramtypmod = typmod;
param->paramcollid = collid;
@@ -1157,6 +1177,54 @@ transformParamRef(ParseState *pstate, ParamRef *pref)
return result;
}
+static Node *
+transformVariableFence(ParseState *pstate, VariableFence *vf)
+{
+ Node *result;
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* VariableFence can be used only in context when variables are supported */
+ if (!expr_kind_allows_session_variables(pstate->p_expr_kind))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable reference is not supported here"),
+ parser_errposition(pstate, vf->location)));
+
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(vf->varname, &attrname, ¬_unique, false);
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ result = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, true, vf->location);
+ }
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ return result;
+}
+
/* Test whether an a_expr is a plain NULL constant or not */
static bool
exprIsNullConstant(Node *arg)
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d5..cf01bff65a9 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -2034,6 +2034,13 @@ FigureColnameInternal(Node *node, char **name)
(int) ((JsonFuncExpr *) node)->op);
}
break;
+ case T_VariableFence:
+ {
+ /* return last field name */
+ *name = strVal(llast(((VariableFence *) node)->varname));
+ return 2;
+ }
+ break;
default:
break;
}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 7417054c38f..106f82b8bb5 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8682,8 +8682,16 @@ get_parameter(Param *param, deparse_context *context)
/* translate paramvarid to session variable name */
if (param->paramkind == PARAM_VARIABLE)
{
- appendStringInfo(context->buf, "%s",
- generate_session_variable_name(param->paramvarid));
+ if (param->paramvarfenced)
+ {
+ appendStringInfo(context->buf, "VARIABLE(%s)",
+ generate_session_variable_name(param->paramvarid));
+ }
+ else
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ }
return;
}
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 491fb06415b..b9626678dc8 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1625,6 +1625,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_use_fence_warning_guard", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when variable is not used inside variable fence."),
+ NULL
+ },
+ &session_variables_use_fence_warning_guard,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 8e17eaca0dd..b84e8659ae1 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -736,6 +736,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_deferrable = off
#session_replication_role = 'origin'
#session_variables_ambiguity_warning = off
+#session_variables_use_fence_warning_guard = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 0270945e048..d5f00cf3702 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -321,6 +321,16 @@ typedef struct ParamRef
ParseLoc location; /* token location, or -1 if unknown */
} ParamRef;
+/*
+ * VariableFence - ensure so fields will be interpretted as a variable
+ */
+typedef struct VariableFence
+{
+ NodeTag type;
+ List *varname; /* variable name (String nodes) */
+ ParseLoc location; /* token location, or -1 if unknown */
+} VariableFence;
+
/*
* A_Expr - infix, prefix, and postfix expressions
*/
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 2fa9b1bcd04..98b9285a54b 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -411,6 +411,8 @@ typedef struct Param
* param is used just for execution of UPDATE operation.
*/
bool parambasenode;
+ /* true when variable is used inside an fence */
+ bool paramvarfenced;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index d2209070181..5bde43758d1 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -18,6 +18,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
extern PGDLLIMPORT bool session_variables_ambiguity_warning;
+extern PGDLLIMPORT bool session_variables_use_fence_warning_guard;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7c350ad5ef9..9ac08a14e0b 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1969,3 +1969,62 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
NOTICE: drop cascades to session variable xxtab.avar
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+CREATE SCHEMA testvar;
+SET search_path TO 'testvar';
+CREATE VARIABLE a AS int;
+LET a = 10;
+CREATE TABLE test_table(a int, b int);
+INSERT INTO test_table VALUES(20, 20);
+-- no warning
+SELECT a;
+ a
+----
+ 10
+(1 row)
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a | b
+----+----
+ 20 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a) FROM test_table;
+ a
+----
+ 10
+(1 row)
+
+ALTER TABLE test_table DROP COLUMN a;
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is not used inside variable fence
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+DROP SCHEMA testvar;
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 68be415bf26..c5420183d94 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1360,3 +1360,44 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
+
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+
+CREATE SCHEMA testvar;
+
+SET search_path TO 'testvar';
+
+CREATE VARIABLE a AS int;
+LET a = 10;
+
+CREATE TABLE test_table(a int, b int);
+
+INSERT INTO test_table VALUES(20, 20);
+
+-- no warning
+SELECT a;
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a) FROM test_table;
+
+ALTER TABLE test_table DROP COLUMN a;
+
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+
+DROP SCHEMA testvar;
+
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
--
2.48.1
[text/x-patch] v20250216-0009-EXPLAIN-LET-support.patch (8.3K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/10-v20250216-0009-EXPLAIN-LET-support.patch)
download | inline diff:
From 6b18ca33acbf59b7241f431eb667f933be783fa2 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 21 May 2024 18:28:07 +0200
Subject: [PATCH 09/21] EXPLAIN LET support
Enhancing ExplainOnePlan is necessary to be EXPLAIN ANALYZE LET fully workable.
In this case we want to be result of query or expression written to target variable.
---
doc/src/sgml/ref/explain.sgml | 3 +-
src/backend/commands/explain.c | 31 ++++++++++++--
src/backend/commands/prepare.c | 5 ++-
src/backend/parser/gram.y | 3 +-
src/include/commands/explain.h | 3 +-
.../regress/expected/session_variables.out | 40 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 21 ++++++++++
7 files changed, 97 insertions(+), 9 deletions(-)
diff --git a/doc/src/sgml/ref/explain.sgml b/doc/src/sgml/ref/explain.sgml
index 6361a14e65d..4292615b447 100644
--- a/doc/src/sgml/ref/explain.sgml
+++ b/doc/src/sgml/ref/explain.sgml
@@ -98,7 +98,8 @@ EXPLAIN [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] <rep
<command>INSERT</command>, <command>UPDATE</command>,
<command>DELETE</command>, <command>MERGE</command>,
<command>CREATE TABLE AS</command>,
- or <command>EXECUTE</command> statement
+ <command>EXECUTE</command>,
+ or <command>LET</command> statement
without letting the command affect your data, use this approach:
<programlisting>
BEGIN;
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index c24e66f82e1..a608f81ef4f 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -18,6 +18,7 @@
#include "commands/createas.h"
#include "commands/defrem.h"
#include "commands/prepare.h"
+#include "executor/svariableReceiver.h"
#include "foreign/fdwapi.h"
#include "jit/jit.h"
#include "libpq/pqformat.h"
@@ -519,8 +520,9 @@ standard_ExplainOneQuery(Query *query, int cursorOptions,
}
/* run it (if needed) and produce output */
- ExplainOnePlan(plan, into, es, queryString, params, queryEnv,
- &planduration, (es->buffers ? &bufusage : NULL),
+ ExplainOnePlan(plan, into, query->resultVariable, es, queryString,
+ params, queryEnv, &planduration,
+ (es->buffers ? &bufusage : NULL),
es->memory ? &mem_counters : NULL);
}
@@ -618,6 +620,25 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
else
ExplainDummyGroup("Notify", NULL, es);
}
+ else if (IsA(utilityStmt, LetStmt))
+ {
+ LetStmt *letstmt = (LetStmt *) utilityStmt;
+ List *rewritten;
+ Query *query;
+
+ if (es->format == EXPLAIN_FORMAT_TEXT)
+ appendStringInfoString(es->str, "SET SESSION VARIABLE\n");
+ else
+ ExplainDummyGroup("Set Session Variable", NULL, es);
+
+ rewritten = QueryRewrite(castNode(Query, copyObject(letstmt->query)));
+
+ Assert(list_length(rewritten) == 1);
+ query = linitial_node(Query, rewritten);
+ ExplainOneQuery(query,
+ CURSOR_OPT_PARALLEL_OK, NULL, es,
+ pstate, params);
+ }
else
{
if (es->format == EXPLAIN_FORMAT_TEXT)
@@ -641,8 +662,8 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
* to call it.
*/
void
-ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
- const char *queryString, ParamListInfo params,
+ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, Oid targetvar,
+ ExplainState *es, const char *queryString, ParamListInfo params,
QueryEnvironment *queryEnv, const instr_time *planduration,
const BufferUsage *bufusage,
const MemoryContextCounters *mem_counters)
@@ -691,6 +712,8 @@ ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into, ExplainState *es,
*/
if (into)
dest = CreateIntoRelDestReceiver(into);
+ else if (OidIsValid(targetvar))
+ dest = CreateVariableDestReceiver(targetvar);
else if (es->serialize != EXPLAIN_SERIALIZE_NONE)
dest = CreateExplainSerializeDestReceiver(es);
else
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 902b022f9c7..4ea2bfea4ea 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -664,8 +664,9 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
PlannedStmt *pstmt = lfirst_node(PlannedStmt, p);
if (pstmt->commandType != CMD_UTILITY)
- ExplainOnePlan(pstmt, into, es, query_string, paramLI, pstate->p_queryEnv,
- &planduration, (es->buffers ? &bufusage : NULL),
+ ExplainOnePlan(pstmt, into, InvalidOid, es, query_string, paramLI,
+ pstate->p_queryEnv, &planduration,
+ (es->buffers ? &bufusage : NULL),
es->memory ? &mem_counters : NULL);
else
ExplainOneUtility(pstmt->utilityStmt, into, es, pstate, paramLI);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index a8c098c3d5a..41d2b35b7c3 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -12167,7 +12167,8 @@ ExplainableStmt:
| CreateAsStmt
| CreateMatViewStmt
| RefreshMatViewStmt
- | ExecuteStmt /* by default all are $$=$1 */
+ | ExecuteStmt
+ | LetStmt /* by default all are $$=$1 */
;
/*****************************************************************************
diff --git a/src/include/commands/explain.h b/src/include/commands/explain.h
index ea7419951f4..de21fe97d01 100644
--- a/src/include/commands/explain.h
+++ b/src/include/commands/explain.h
@@ -103,7 +103,8 @@ extern void ExplainOneUtility(Node *utilityStmt, IntoClause *into,
ExplainState *es, ParseState *pstate,
ParamListInfo params);
-extern void ExplainOnePlan(PlannedStmt *plannedstmt, IntoClause *into,
+extern void ExplainOnePlan(PlannedStmt *plannedstmt,
+ IntoClause *into, Oid targetvar,
ExplainState *es, const char *queryString,
ParamListInfo params, QueryEnvironment *queryEnv,
const instr_time *planduration,
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 9ac08a14e0b..0cae7454545 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2028,3 +2028,43 @@ DROP SCHEMA testvar;
SET session_variables_ambiguity_warning TO DEFAULT;
SET session_variables_use_fence_warning_guard TO DEFAULT;
SET search_path TO DEFAULT;
+CREATE VARIABLE var1 bigint;
+CREATE TABLE var_tab_test_table(a int);
+INSERT INTO var_tab_test_table SELECT * FROM generate_series(1,10);
+VACUUM ANALYZE var_tab_test_table;
+EXPLAIN (COSTS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+ QUERY PLAN
+----------------------------------------------
+ SET SESSION VARIABLE
+ Result
+ InitPlan 1
+ -> Aggregate
+ -> Seq Scan on var_tab_test_table
+(5 rows)
+
+-- should be NULL
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+ QUERY PLAN
+-----------------------------------------------------------------------
+ SET SESSION VARIABLE
+ Result (actual rows=1 loops=1)
+ InitPlan 1
+ -> Aggregate (actual rows=1 loops=1)
+ -> Seq Scan on var_tab_test_table (actual rows=10 loops=1)
+(5 rows)
+
+-- should be 10
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1;
+DROP TABLE var_tab_test_table;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index c5420183d94..3d0eb8c7ad9 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1401,3 +1401,24 @@ DROP SCHEMA testvar;
SET session_variables_ambiguity_warning TO DEFAULT;
SET session_variables_use_fence_warning_guard TO DEFAULT;
SET search_path TO DEFAULT;
+
+CREATE VARIABLE var1 bigint;
+
+CREATE TABLE var_tab_test_table(a int);
+
+INSERT INTO var_tab_test_table SELECT * FROM generate_series(1,10);
+
+VACUUM ANALYZE var_tab_test_table;
+
+EXPLAIN (COSTS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+
+-- should be NULL
+SELECT var1;
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+
+-- should be 10
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP TABLE var_tab_test_table;
--
2.48.1
[text/x-patch] v20250216-0012-Implementation-ON-TRANSACTION-END-RESET-clause.patch (14.6K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/11-v20250216-0012-Implementation-ON-TRANSACTION-END-RESET-clause.patch)
download | inline diff:
From f2c1741f144dddcc10fe21e8e297e5bf8c29459b Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:02:13 +0100
Subject: [PATCH 12/21] Implementation ON TRANSACTION END RESET clause
This is simple patch - just add special flag to session variable memory entry.
The entries with active this flag are removed from sessionvars hash table
at transaction end. The "TRANSACTION END" is synonyms for "COMMIT ROLLBACK"
but the "TRANSACTION END" is more illustrative and less confusing then "COMMIT ROLLBACK".
---
doc/src/sgml/catalogs.sgml | 3 +-
doc/src/sgml/ref/create_variable.sgml | 13 ++++-
src/backend/commands/session_variable.c | 51 +++++++++++++++++++
src/backend/parser/gram.y | 1 +
src/bin/pg_dump/pg_dump.c | 11 ++++
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_dump/t/002_pg_dump.pl | 18 +++++++
src/bin/psql/describe.c | 1 +
src/include/catalog/pg_variable.h | 1 +
.../isolation/expected/session-variable.out | 4 +-
.../isolation/specs/session-variable.spec | 4 +-
.../regress/expected/session_variables.out | 34 +++++++++++++
src/test/regress/sql/session_variables.sql | 20 ++++++++
13 files changed, 158 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 09b635c234a..687d1c8733a 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9871,7 +9871,8 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para>
<para>
Action performed at end of transaction:
- <literal>n</literal> = no action, <literal>d</literal> = drop the variable.
+ <literal>n</literal> = no action, <literal>d</literal> = drop the variable,
+ <literal>r</literal> = reset the variable to its default value.
</para></entry>
</row>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index a88e0175bea..c89a65fb55f 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -27,7 +27,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
- [ ON COMMIT DROP ]
+ [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -117,6 +117,17 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-on-transaction-end-reset">
+ <term><literal>ON TRANSACTION END RESET</literal></term>
+ <listitem>
+ <para>
+ The <literal>ON TRANSACTION END RESET</literal> clause causes the session
+ variable to be reset to its default value when the transaction is committed
+ or rolled back.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</refsect1>
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 03e0b6900ca..035e5da08f2 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -83,6 +83,8 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ bool reset_at_eox;
+
/*
* Top level local transaction id of the last transaction that dropped the
* variable, if any. We need this information to avoid freeing memory for
@@ -110,6 +112,12 @@ static MemoryContext SVariableMemoryContext = NULL;
/* becomes true when we receive a sinval message */
static bool needs_validation = false;
+/*
+ * true, when some used session variable has ON COMMIT DROP
+ * or ON TRANSACTION END RESET clauses
+ */
+static bool has_session_variables_with_reset_at_eox = false;
+
/*
* The content of dropped session variables is not removed immediately. If
* possible, we do that at the end of the transaction. But we cannot do that
@@ -385,6 +393,32 @@ remove_invalid_session_variables(bool atEOX)
}
}
+/*
+ * remove entries marked as "reset_at_eox"
+ */
+static void
+remove_session_variables_with_reset_at_eox(void)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ if (!sessionvars)
+ return;
+
+ /* leave quckly, when there are not that variables */
+ if (!has_session_variables_with_reset_at_eox)
+ return;
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (svar->reset_at_eox)
+ hash_search(sessionvars, &svar->varid, HASH_REMOVE, NULL);
+ }
+
+ has_session_variables_with_reset_at_eox = false;
+}
+
/*
* Perform ON COMMIT DROP for temporary session variables,
* and remove all dropped variables from memory.
@@ -392,6 +426,8 @@ remove_invalid_session_variables(bool atEOX)
void
AtPreEOXact_SessionVariables(bool isCommit)
{
+ remove_session_variables_with_reset_at_eox();
+
if (isCommit)
{
if (xact_drop_items)
@@ -503,6 +539,21 @@ setup_session_variable(SVariable svar, Oid varid)
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+ /*
+ * We don't need to explicitly reset variables marked ON COMMIT DROP. It
+ * can be done by sinval message processing. But this processing can be
+ * postponed due aborted transaction. On second hand there is not a
+ * reason, why don't do it at transaction end immediately.
+ */
+ if (varform->varxactendaction == VARIABLE_XACTEND_RESET ||
+ varform->varxactendaction == VARIABLE_XACTEND_DROP)
+ {
+ svar->reset_at_eox = true;
+ has_session_variables_with_reset_at_eox = true;
+ }
+ else
+ svar->reset_at_eox = false;
+
svar->drop_lxid = InvalidTransactionId;
svar->isnull = true;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 2af037d2669..52e11c8d770 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -5293,6 +5293,7 @@ CreateSessionVarStmt:
* transaction end like tables.
*/
XactEndActionOption: ON COMMIT DROP { $$ = VARIABLE_XACTEND_DROP; }
+ | ON TRANSACTION END_P RESET { $$ = VARIABLE_XACTEND_RESET; }
| /*EMPTY*/ { $$ = VARIABLE_XACTEND_NOOP; }
;
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 4771ab5494a..83fd38cae34 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5440,6 +5440,7 @@ getVariables(Archive *fout)
int i_varnamespace;
int i_vartype;
int i_vartypname;
+ int i_varxactendaction;
int i_varowner;
int i_varcollation;
int i_varacl;
@@ -5455,6 +5456,7 @@ getVariables(Archive *fout)
/* get the variables in current database */
appendPQExpBuffer(query,
"SELECT v.tableoid, v.oid, v.varname,\n"
+ " v.varxactendaction,\n"
" v.varnamespace, v.vartype,\n"
" pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n"
" CASE WHEN v.varcollation <> t.typcollation "
@@ -5477,6 +5479,7 @@ getVariables(Archive *fout)
i_varnamespace = PQfnumber(res, "varnamespace");
i_vartype = PQfnumber(res, "vartype");
i_vartypname = PQfnumber(res, "vartypname");
+ i_varxactendaction = PQfnumber(res, "varxactendaction");
i_varcollation = PQfnumber(res, "varcollation");
i_varowner = PQfnumber(res, "varowner");
@@ -5500,6 +5503,9 @@ getVariables(Archive *fout)
varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype));
varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname));
+ varinfo[i].varxactendaction =
+ pg_strdup(PQgetvalue(res, i, i_varxactendaction));
+
varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
@@ -5540,6 +5546,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
PQExpBuffer query;
char *qualvarname;
const char *vartypname;
+ const char *varxactendaction;
Oid varcollation;
/* skip if not to be dumped */
@@ -5551,6 +5558,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
vartypname = varinfo->vartypname;
+ varxactendaction = varinfo->varxactendaction;
varcollation = varinfo->varcollation;
appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
@@ -5569,6 +5577,9 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
fmtQualifiedDumpable(coll));
}
+ if (strcmp(varxactendaction, "r") == 0)
+ appendPQExpBuffer(query, " ON TRANSACTION END RESET");
+
appendPQExpBuffer(query, ";\n");
if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index 125384cf3f0..e815b411f0f 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -718,6 +718,7 @@ typedef struct _VariableInfo
DumpableAcl dacl;
Oid vartype;
char *vartypname;
+ char *varxactendaction;
Oid varcollation;
const char *rolname; /* name of owner, or empty string */
} VariableInfo;
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index b84dcf0cab9..4a70f4cd699 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4054,6 +4054,24 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable ON TRANSACTION END RESET' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable2 AS integer ON TRANSACTION END RESET;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable2 AS integer ON TRANSACTION END RESET;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a3fca34c7d7..d3b1442eb2f 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5354,6 +5354,7 @@ listVariables(const char *pattern, bool verbose)
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
+ " WHEN 'r' THEN 'ON TRANSACTION END RESET'\n"
" END as \"%s\"\n",
gettext_noop("Schema"),
gettext_noop("Name"),
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 0fc672bc2ba..008f2ee7c17 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -75,6 +75,7 @@ typedef enum VariableXactEndAction
{
VARIABLE_XACTEND_NOOP = 'n', /* NOOP */
VARIABLE_XACTEND_DROP = 'd', /* ON COMMIT DROP */
+ VARIABLE_XACTEND_RESET = 'r', /* ON TRANSACTION END RESET */
} VariableXactEndAction;
/* ----------------
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
index a609797dc5d..e9a254bcd12 100644
--- a/src/test/isolation/expected/session-variable.out
+++ b/src/test/isolation/expected/session-variable.out
@@ -86,11 +86,12 @@ myvar
step sr1: ROLLBACK;
-starting permutation: create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
+starting permutation: create3 let3 s3 o_c_d o_eox_r create4 let4 drop4 drop3 inval3 discard sc3 clean state
step create3: CREATE VARIABLE myvar3 AS text;
step let3: LET myvar3 = 'test';
step s3: BEGIN;
step o_c_d: CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP;
+step o_eox_r: CREATE VARIABLE myvar_o_eox_r AS text ON TRANSACTION END RESET; LET myvar_o_eox_r = 'test';
step create4: CREATE VARIABLE myvar4 AS text;
step let4: LET myvar4 = 'test';
step drop4: DROP VARIABLE myvar4;
@@ -103,6 +104,7 @@ t
step discard: DISCARD VARIABLES;
step sc3: COMMIT;
+step clean: DROP VARIABLE myvar_o_eox_r;
step state: SELECT varname FROM pg_variable;
varname
-------
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
index 45e65d4085d..5d089c8a4ed 100644
--- a/src/test/isolation/specs/session-variable.spec
+++ b/src/test/isolation/specs/session-variable.spec
@@ -25,12 +25,14 @@ session s3
step s3 { BEGIN; }
step let3 { LET myvar3 = 'test'; }
step o_c_d { CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP; }
+step o_eox_r { CREATE VARIABLE myvar_o_eox_r AS text ON TRANSACTION END RESET; LET myvar_o_eox_r = 'test'; }
step create4 { CREATE VARIABLE myvar4 AS text; }
step let4 { LET myvar4 = 'test'; }
step drop4 { DROP VARIABLE myvar4; }
step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; }
step discard { DISCARD VARIABLES; }
step sc3 { COMMIT; }
+step clean { DROP VARIABLE myvar_o_eox_r; }
step state { SELECT varname FROM pg_variable; }
session s4
@@ -48,4 +50,4 @@ permutation let val dbg drop create dbg val
# calling the dbg step after the concurrent drop
permutation let val s1 dbg drop create dbg val sr1
# test for DISCARD ALL when all internal queues have actions registered
-permutation create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
+permutation create3 let3 s3 o_c_d o_eox_r create4 let4 drop4 drop3 inval3 discard sc3 clean state
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 14e093eb8a7..7b3ed43618f 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2265,3 +2265,37 @@ SELECT count(*) FROM pg_session_variables();
0
(1 row)
+CREATE VARIABLE var1 AS int ON TRANSACTION END RESET;
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+COMMIT;
+-- should be NULL;
+SELECT var1 IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be NULL
+SELECT var1 IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+DROP VARIABLE var1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index e6ccc37153d..d6e7c21bf16 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1545,3 +1545,23 @@ COMMIT;
SELECT count(*) FROM pg_variable WHERE varname = 'var1';
-- should be zero
SELECT count(*) FROM pg_session_variables();
+
+CREATE VARIABLE var1 AS int ON TRANSACTION END RESET;
+
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+COMMIT;
+
+-- should be NULL;
+SELECT var1 IS NULL;
+
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+ROLLBACK;
+
+-- should be NULL
+SELECT var1 IS NULL;
+
+DROP VARIABLE var1;
--
2.48.1
[text/x-patch] v20250216-0010-PREPARE-LET-support.patch (7.4K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/12-v20250216-0010-PREPARE-LET-support.patch)
download | inline diff:
From dfff42a3ff3e1cceeed5670acfc4718baeebfc13 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 09:44:58 +0100
Subject: [PATCH 10/21] PREPARE LET support
In current code base it requires just small changes in parser. It is nice
to have to have possibility to use prepared LET statements mainly due reduction
of security risks (SQL injection), and implementation is almost cheap.
Explicit preparing is not necessity for support of LET statements in PL, because
PL uses SPI for query execution, but it is nice to have this possibility (completenees, ...)
---
doc/src/sgml/ref/prepare.sgml | 4 +-
src/backend/parser/gram.y | 3 +-
src/backend/parser/parse_cte.c | 7 ++
src/bin/psql/tab-complete.in.c | 4 +-
.../regress/expected/session_variables.out | 81 ++++++++++++++++++-
src/test/regress/sql/session_variables.sql | 57 +++++++++++++
6 files changed, 149 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/ref/prepare.sgml b/doc/src/sgml/ref/prepare.sgml
index 8ee9439f611..45d72b1d52b 100644
--- a/doc/src/sgml/ref/prepare.sgml
+++ b/doc/src/sgml/ref/prepare.sgml
@@ -116,8 +116,8 @@ PREPARE <replaceable class="parameter">name</replaceable> [ ( <replaceable class
<listitem>
<para>
Any <command>SELECT</command>, <command>INSERT</command>, <command>UPDATE</command>,
- <command>DELETE</command>, <command>MERGE</command>, or <command>VALUES</command>
- statement.
+ <command>DELETE</command>, <command>MERGE</command>, <command>VALUES</command>,
+ or <command>LET</command> statement.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 41d2b35b7c3..b5bd1093572 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -12198,7 +12198,8 @@ PreparableStmt:
| InsertStmt
| UpdateStmt
| DeleteStmt
- | MergeStmt /* by default all are $$=$1 */
+ | MergeStmt
+ | LetStmt /* by default all are $$=$1 */
;
/*****************************************************************************
diff --git a/src/backend/parser/parse_cte.c b/src/backend/parser/parse_cte.c
index 79673621c9b..c62761e4eae 100644
--- a/src/backend/parser/parse_cte.c
+++ b/src/backend/parser/parse_cte.c
@@ -126,6 +126,13 @@ transformWithClause(ParseState *pstate, WithClause *withClause)
CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
ListCell *rest;
+ /* LET is allowed by parser, but not supported. Reject for now */
+ if (IsA(cte->ctequery, LetStmt))
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("LET not supported in WITH query"),
+ parser_errposition(pstate, cte->location));
+
for_each_cell(rest, withClause->ctes, lnext(withClause->ctes, lc))
{
CommonTableExpr *cte2 = (CommonTableExpr *) lfirst(rest);
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 0cc8eb56bb4..d9bb96ad318 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4664,9 +4664,9 @@ match_previous_words(int pattern_id,
else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES"))
COMPLETE_WITH("(");
-/* LET */
+/* LET, EXPLAIN LET, PREPARE LET */
/* If prev. word is LET suggest a list of variables */
- else if (Matches("LET"))
+ else if (TailMatches("LET"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
/* Complete LET <variable> with "=" */
else if (TailMatches("LET", MatchAny))
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 0cae7454545..6049f689f24 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -940,9 +940,9 @@ DROP VARIABLE var1, var2;
-- the LET statement should be disallowed in CTE
CREATE VARIABLE var1 AS int;
WITH x AS (LET var1 = 100) SELECT * FROM x;
-ERROR: syntax error at or near "LET"
+ERROR: LET not supported in WITH query
LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x;
- ^
+ ^
-- should be ok
LET var1 = generate_series(1, 1);
-- should fail
@@ -2066,5 +2066,82 @@ SELECT var1;
10
(1 row)
+SET plan_cache_mode TO force_generic_plan;
+PREPARE p1 AS LET var1 = (SELECT count(*) FROM var_tab_test_table);
+LET var1 = NULL;
+EXPLAIN (COSTS OFF) EXECUTE p1;
+ QUERY PLAN
+----------------------------------------------
+ SET SESSION VARIABLE
+ Result
+ InitPlan 1
+ -> Aggregate
+ -> Seq Scan on var_tab_test_table
+(5 rows)
+
+-- should be NULL
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) EXECUTE p1;
+ QUERY PLAN
+-----------------------------------------------------------------------
+ SET SESSION VARIABLE
+ Result (actual rows=1 loops=1)
+ InitPlan 1
+ -> Aggregate (actual rows=1 loops=1)
+ -> Seq Scan on var_tab_test_table (actual rows=10 loops=1)
+(5 rows)
+
+-- should be 10
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SET plan_cache_mode TO DEFAULT;
+DEALLOCATE p1;
DROP VARIABLE var1;
DROP TABLE var_tab_test_table;
+CREATE VARIABLE var1 numeric;
+SET plan_cache_mode TO force_generic_plan;
+PREPARE p1(numeric) AS LET var1 = $1;
+PREPARE p2 AS SELECT var1;
+EXECUTE p1(pi() + 100);
+EXECUTE p2;
+ var1
+-----------------
+ 103.14159265359
+(1 row)
+
+-- prepared plan cache invalidation test
+DROP VARIABLE var1;
+CREATE VARIABLE var1 numeric;
+-- should be NULL
+EXECUTE p2;
+ var1
+------
+
+(1 row)
+
+DEALLOCATE p1;
+DEALLOCATE p2;
+DROP VARIABLE var1;
+SET plan_cache_mode TO force_generic_plan;
+CREATE VARIABLE var1 numeric[];
+PREPARE p1(int, numeric) AS LET var1[$1] = $2;
+LET var1 = '{}'::numeric[];
+EXECUTE p1(1, 10.2);
+EXECUTE p1(2, 10.3);
+SELECT var1;
+ var1
+-------------
+ {10.2,10.3}
+(1 row)
+
+DEALLOCATE p1;
+DROP VARIABLE var1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 3d0eb8c7ad9..18b59fc9cad 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1420,5 +1420,62 @@ EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) LET var1 = (S
-- should be 10
SELECT var1;
+SET plan_cache_mode TO force_generic_plan;
+
+PREPARE p1 AS LET var1 = (SELECT count(*) FROM var_tab_test_table);
+
+LET var1 = NULL;
+
+EXPLAIN (COSTS OFF) EXECUTE p1;
+
+-- should be NULL
+SELECT var1;
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) EXECUTE p1;
+
+-- should be 10
+SELECT var1;
+
+SET plan_cache_mode TO DEFAULT;
+
+DEALLOCATE p1;
+
DROP VARIABLE var1;
DROP TABLE var_tab_test_table;
+
+CREATE VARIABLE var1 numeric;
+
+SET plan_cache_mode TO force_generic_plan;
+
+PREPARE p1(numeric) AS LET var1 = $1;
+PREPARE p2 AS SELECT var1;
+
+EXECUTE p1(pi() + 100);
+EXECUTE p2;
+
+-- prepared plan cache invalidation test
+DROP VARIABLE var1;
+CREATE VARIABLE var1 numeric;
+
+-- should be NULL
+EXECUTE p2;
+
+DEALLOCATE p1;
+DEALLOCATE p2;
+
+DROP VARIABLE var1;
+
+SET plan_cache_mode TO force_generic_plan;
+
+CREATE VARIABLE var1 numeric[];
+
+PREPARE p1(int, numeric) AS LET var1[$1] = $2;
+
+LET var1 = '{}'::numeric[];
+EXECUTE p1(1, 10.2);
+EXECUTE p1(2, 10.3);
+
+SELECT var1;
+
+DEALLOCATE p1;
+DROP VARIABLE var1;
--
2.48.1
[text/x-patch] v20250216-0011-implementation-of-temporary-session-variables.patch (40.7K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/13-v20250216-0011-implementation-of-temporary-session-variables.patch)
download | inline diff:
From b10875f593aa423a93782fee32314891858f0bd9 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:00:28 +0100
Subject: [PATCH 11/21] implementation of temporary session variables
The temporary variables are created inside temp schema and they are dropped by dropping
this schema. For consistency with temp tables, the CREATE TEMP VARIABLE command supports
ON COMMIT DROP clause. The temporary variables with this clause are collected in xact_drop_items
list. This list should be carefully maintained and can contain only valid entries (not
yet dropped). From this reasons now the subcommit and subaborting have to be handled.
---
doc/src/sgml/catalogs.sgml | 10 +
doc/src/sgml/ddl.sgml | 6 +-
doc/src/sgml/ref/create_variable.sgml | 15 +-
src/backend/access/transam/xact.c | 9 +
src/backend/catalog/pg_variable.c | 27 ++-
src/backend/commands/session_variable.c | 218 +++++++++++++++++-
src/backend/commands/view.c | 2 +-
src/backend/parser/analyze.c | 4 +-
src/backend/parser/gram.y | 30 ++-
src/backend/parser/parse_relation.c | 22 +-
src/bin/psql/describe.c | 10 +-
src/bin/psql/tab-complete.in.c | 5 +-
src/include/catalog/pg_variable.h | 9 +
src/include/commands/session_variable.h | 6 +-
src/include/nodes/parsenodes.h | 1 +
src/include/nodes/primnodes.h | 4 +-
src/include/parser/parse_relation.h | 2 +-
.../isolation/expected/session-variable.out | 3 +-
.../isolation/specs/session-variable.spec | 3 +-
src/test/regress/expected/psql.out | 36 +--
.../regress/expected/session_variables.out | 120 ++++++++++
src/test/regress/sql/session_variables.sql | 66 ++++++
src/tools/pgindent/typedefs.list | 1 +
23 files changed, 544 insertions(+), 65 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 4f502274bfa..09b635c234a 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9865,6 +9865,16 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varxactendaction</structfield> <type>char</type>
+ </para>
+ <para>
+ Action performed at end of transaction:
+ <literal>n</literal> = no action, <literal>d</literal> = drop the variable.
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>varcollation</structfield> <type>oid</type>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4e8e7c6a42a..3e2cb3c46eb 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5412,9 +5412,9 @@ SELECT current_user_id;
<command>LET</command> command. Session variables are not transactional:
any changes made to the value of a session variable in a transaction won't
be undone if the transaction is rolled back (just like variables in
- procedural languages). Session variables themselves are persistent, but
- their values are neither persistent nor shared (like the content of
- temporary tables).
+ procedural languages). Session variables themselves can be persistent
+ or temporary, but their values are neither persistent nor shared (like the
+ content of temporary tables).
</para>
<para>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index cd9ff63975a..a88e0175bea 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -26,7 +26,8 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+ [ ON COMMIT DROP ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -104,6 +105,18 @@ CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceab
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-on-commit-drop">
+ <term><literal>ON COMMIT DROP</literal></term>
+ <listitem>
+ <para>
+ The <literal>ON COMMIT DROP</literal> clause specifies the behaviour of a
+ temporary session variable at transaction commit. With this clause, the
+ session variable is dropped at commit time. The clause is only allowed
+ for temporary variables.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</refsect1>
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 1b4f21a88d3..4e6216306da 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -36,6 +36,7 @@
#include "catalog/pg_enum.h"
#include "catalog/storage.h"
#include "commands/async.h"
+#include "commands/session_variable.h"
#include "commands/tablecmds.h"
#include "commands/trigger.h"
#include "common/pg_prng.h"
@@ -2316,6 +2317,9 @@ CommitTransaction(void)
*/
smgrDoPendingSyncs(true, is_parallel_worker);
+ /* remove values of dropped session variables from memory */
+ AtPreEOXact_SessionVariables(true);
+
/* close large objects before lower-level cleanup */
AtEOXact_LargeObject(true);
@@ -2912,6 +2916,7 @@ AbortTransaction(void)
AtAbort_Portals();
smgrDoPendingSyncs(false, is_parallel_worker);
AtEOXact_LargeObject(false);
+ AtPreEOXact_SessionVariables(false);
AtAbort_Notify();
AtEOXact_RelationMap(false, is_parallel_worker);
AtAbort_Twophase();
@@ -5177,6 +5182,8 @@ CommitSubTransaction(void)
AtEOSubXact_SPI(true, s->subTransactionId);
AtEOSubXact_on_commit_actions(true, s->subTransactionId,
s->parent->subTransactionId);
+ AtEOSubXact_SessionVariables(true, s->subTransactionId,
+ s->parent->subTransactionId);
AtEOSubXact_Namespace(true, s->subTransactionId,
s->parent->subTransactionId);
AtEOSubXact_Files(true, s->subTransactionId,
@@ -5342,6 +5349,8 @@ AbortSubTransaction(void)
AtEOSubXact_SPI(false, s->subTransactionId);
AtEOSubXact_on_commit_actions(false, s->subTransactionId,
s->parent->subTransactionId);
+ AtEOSubXact_SessionVariables(false, s->subTransactionId,
+ s->parent->subTransactionId);
AtEOSubXact_Namespace(false, s->subTransactionId,
s->parent->subTransactionId);
AtEOSubXact_Files(false, s->subTransactionId,
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index d672d2a9cb3..00c90ea6fd8 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -36,7 +36,8 @@ static ObjectAddress create_variable(const char *varName,
int32 varTypmod,
Oid varOwner,
Oid varCollation,
- bool if_not_exists);
+ bool if_not_exists,
+ VariableXactEndAction varXactEndAction);
/*
@@ -49,7 +50,8 @@ create_variable(const char *varName,
int32 varTypmod,
Oid varOwner,
Oid varCollation,
- bool if_not_exists)
+ bool if_not_exists,
+ VariableXactEndAction varXactEndAction)
{
Acl *varacl;
NameData varname;
@@ -110,6 +112,7 @@ create_variable(const char *varName,
values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+ values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
varNamespace);
@@ -183,6 +186,13 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
Oid typcollation;
ObjectAddress variable;
+ /* check consistency of arguments */
+ if (stmt->XactEndAction == VARIABLE_XACTEND_DROP
+ && stmt->variable->relpersistence != RELPERSISTENCE_TEMP)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+ errmsg("ON COMMIT DROP can only be used on temporary variables")));
+
namespaceid =
RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL);
@@ -222,11 +232,17 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
typmod,
varowner,
collation,
- stmt->if_not_exists);
+ stmt->if_not_exists,
+ stmt->XactEndAction);
elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
stmt->variable->relname, variable.objectId);
+ /* we want SessionVariableCreatePostprocess to see the catalog changes. */
+ CommandCounterIncrement();
+
+ SessionVariableCreatePostprocess(variable.objectId, stmt->XactEndAction);
+
return variable;
}
@@ -239,6 +255,7 @@ DropVariableById(Oid varid)
{
Relation rel;
HeapTuple tup;
+ char XactEndAction;
rel = table_open(VariableRelationId, RowExclusiveLock);
@@ -247,6 +264,8 @@ DropVariableById(Oid varid)
if (!HeapTupleIsValid(tup))
elog(ERROR, "cache lookup failed for variable %u", varid);
+ XactEndAction = ((Form_pg_variable) GETSTRUCT(tup))->varxactendaction;
+
CatalogTupleDelete(rel, &tup->t_self);
ReleaseSysCache(tup);
@@ -254,5 +273,5 @@ DropVariableById(Oid varid)
table_close(rel, RowExclusiveLock);
/* do the necessary cleanup in local memory, if needed */
- SessionVariableDropPostprocess(varid);
+ SessionVariableDropPostprocess(varid, XactEndAction);
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 4a29ed6e0c3..03e0b6900ca 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -16,6 +16,8 @@
#include "access/xact.h"
#include "catalog/pg_variable.h"
+#include "catalog/dependency.h"
+#include "catalog/namespace.h"
#include "commands/session_variable.h"
#include "executor/svariableReceiver.h"
#include "funcapi.h"
@@ -31,6 +33,19 @@
#include "utils/snapmgr.h"
#include "utils/syscache.h"
+typedef struct SVariableXActDropItem
+{
+ Oid varid; /* varid of session variable */
+
+ /*
+ * creating_subid is the ID of the creating subxact. If the action was
+ * unregistered during the current transaction, deleting_subid is the ID
+ * of the deleting subxact, otherwise InvalidSubTransactionId.
+ */
+ SubTransactionId creating_subid;
+ SubTransactionId deleting_subid;
+} SVariableXActDropItem;
+
/*
* The values of session variables are stored in the backend's private memory
* in the dedicated memory context SVariableMemoryContext in binary format.
@@ -96,13 +111,21 @@ static MemoryContext SVariableMemoryContext = NULL;
static bool needs_validation = false;
/*
- * The content of dropped session variables is not removed immediately. We do
- * that in the next transaction that reads or writes a session variable.
- * "validated_lxid" stores the transaction that performed said validation, so
- * that we can avoid repeating the effort.
+ * The content of dropped session variables is not removed immediately. If
+ * possible, we do that at the end of the transaction. But we cannot do that
+ * if the transaction aborted, because we lost access to the system catalog.
+ * In that case, we clean up in the next transaction that reads or writes a
+ * session variable. "validated_lxid" stores the transaction that performed
+ * said validation, so that we can avoid repeating the effort.
*/
static LocalTransactionId validated_lxid = InvalidLocalTransactionId;
+/* list holds fields of SVariableXActDropItem type */
+static List *xact_drop_items = NIL;
+
+static void register_session_variable_xact_drop(Oid varid);
+static void unregister_session_variable_xact_drop(Oid varid);
+
/*
* Callback function for session variable invalidation.
*/
@@ -139,16 +162,45 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
}
}
+/*
+ * Do the necessary work to setup local memory management of a new
+ * variable.
+ *
+ * Caller should already have created the necessary entry in catalog
+ * and made them visible.
+ */
+void
+SessionVariableCreatePostprocess(Oid varid, char XactEndAction)
+{
+ /*
+ * For temporary variables, we need to create a new end of xact action to
+ * ensure deletion from catalog.
+ */
+ if (XactEndAction == VARIABLE_XACTEND_DROP)
+ {
+ Assert(isTempNamespace(get_session_variable_namespace(varid)));
+
+ register_session_variable_xact_drop(varid);
+ }
+}
+
/*
* Handle the local memory cleanup for a DROP VARIABLE command.
*
* Caller should take care of removing the pg_variable entry first.
*/
void
-SessionVariableDropPostprocess(Oid varid)
+SessionVariableDropPostprocess(Oid varid, char XactEndAction)
{
Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid));
+ if (XactEndAction == VARIABLE_XACTEND_DROP)
+ {
+ Assert(isTempNamespace(get_session_variable_namespace(varid)));
+
+ unregister_session_variable_xact_drop(varid);
+ }
+
if (sessionvars)
{
bool found;
@@ -170,6 +222,57 @@ SessionVariableDropPostprocess(Oid varid)
}
}
+/*
+ * Registration of actions to be executed on session variables at transaction
+ * end time. We want to drop temporary session variables with clause ON COMMIT
+ * DROP.
+ */
+
+/*
+ * Register a session variable xact action.
+ */
+static void
+register_session_variable_xact_drop(Oid varid)
+{
+ SVariableXActDropItem *xact_ai;
+ MemoryContext oldcxt;
+
+ oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
+
+ xact_ai = (SVariableXActDropItem *)
+ palloc(sizeof(SVariableXActDropItem));
+
+ xact_ai->varid = varid;
+
+ xact_ai->creating_subid = GetCurrentSubTransactionId();
+ xact_ai->deleting_subid = InvalidSubTransactionId;
+
+ xact_drop_items = lcons(xact_ai, xact_drop_items);
+
+ MemoryContextSwitchTo(oldcxt);
+}
+
+/*
+ * Unregister an id of a given session variable from drop list. In this
+ * moment, the action is just marked as deleted by setting deleting_subid. The
+ * calling even might be rollbacked, in which case we should not lose this
+ * action.
+ */
+static void
+unregister_session_variable_xact_drop(Oid varid)
+{
+ ListCell *l;
+
+ foreach(l, xact_drop_items)
+ {
+ SVariableXActDropItem *xact_ai =
+ (SVariableXActDropItem *) lfirst(l);
+
+ if (xact_ai->varid == varid)
+ xact_ai->deleting_subid = GetCurrentSubTransactionId();
+ }
+}
+
/*
* Release stored value, free memory
*/
@@ -222,9 +325,11 @@ is_session_variable_valid(SVariable svar)
/*
* Check all potentially invalid session variable data in local memory and free
* the memory for all invalid ones. This function is called before any read or
- * write of a session variable. Freeing of a variable's memory is postponed if
- * the variable has been dropped by the current transaction, since that
- * operation could still be rolled back.
+ * write of a session variable or when the transaction ends. At the end of a
+ * transaction (atEOX is true) we can discard all invalid variables. Inside a
+ * transaction (atEOX is false) we postpone freeing a variable's memory if the
+ * variable has been dropped by the current transaction, since that operation
+ * could still be rolled back.
*
* It is possible that we receive a cache invalidation message while
* remove_invalid_session_variables() is executing, so we cannot guarantee that
@@ -232,7 +337,7 @@ is_session_variable_valid(SVariable svar)
* done. However, we can guarantee that all entries get checked once.
*/
static void
-remove_invalid_session_variables(void)
+remove_invalid_session_variables(bool atEOX)
{
HASH_SEQ_STATUS status;
SVariable svar;
@@ -259,7 +364,7 @@ remove_invalid_session_variables(void)
{
if (!svar->is_valid)
{
- if (svar->drop_lxid == MyProc->vxid.lxid)
+ if (!atEOX && svar->drop_lxid == MyProc->vxid.lxid)
{
/* try again in the next transaction */
needs_validation = true;
@@ -280,6 +385,95 @@ remove_invalid_session_variables(void)
}
}
+/*
+ * Perform ON COMMIT DROP for temporary session variables,
+ * and remove all dropped variables from memory.
+ */
+void
+AtPreEOXact_SessionVariables(bool isCommit)
+{
+ if (isCommit)
+ {
+ if (xact_drop_items)
+ {
+ ListCell *l;
+
+ foreach(l, xact_drop_items)
+ {
+ SVariableXActDropItem *xact_ai =
+ (SVariableXActDropItem *) lfirst(l);
+
+ /* iterate only over entries that are still pending */
+ if (xact_ai->deleting_subid == InvalidSubTransactionId)
+ {
+ ObjectAddress object;
+
+ object.classId = VariableRelationId;
+ object.objectId = xact_ai->varid;
+ object.objectSubId = 0;
+
+ /*
+ * Since this is an automatic drop, rather than one
+ * directly initiated by the user, we pass the
+ * PERFORM_DELETION_INTERNAL flag.
+ */
+ elog(DEBUG1, "session variable (oid:%u) will be deleted (forced by ON COMMIT DROP clause)",
+ xact_ai->varid);
+
+ performDeletion(&object, DROP_CASCADE,
+ PERFORM_DELETION_INTERNAL |
+ PERFORM_DELETION_QUIETLY);
+ }
+ }
+ }
+
+ remove_invalid_session_variables(true);
+ }
+
+ /*
+ * We have to clean xact_drop_items. All related variables are dropped
+ * now, or lost inside aborted transaction.
+ */
+ list_free_deep(xact_drop_items);
+ xact_drop_items = NULL;
+}
+
+/*
+ * Post-subcommit or post-subabort cleanup of xact drop list.
+ *
+ * During subabort, we can immediately remove entries created during this
+ * subtransaction. During subcommit, just transfer entries marked during
+ * this subtransaction as being the parent's responsibility.
+ */
+void
+AtEOSubXact_SessionVariables(bool isCommit,
+ SubTransactionId mySubid,
+ SubTransactionId parentSubid)
+{
+ ListCell *cur_item;
+
+ foreach(cur_item, xact_drop_items)
+ {
+ SVariableXActDropItem *xact_ai =
+ (SVariableXActDropItem *) lfirst(cur_item);
+
+ if (!isCommit && xact_ai->creating_subid == mySubid)
+ {
+ /* cur_item must be removed */
+ xact_drop_items = foreach_delete_current(xact_drop_items, cur_item);
+ pfree(xact_ai);
+ }
+ else
+ {
+ /* cur_item must be preserved */
+ if (xact_ai->creating_subid == mySubid)
+ xact_ai->creating_subid = parentSubid;
+ if (xact_ai->deleting_subid == mySubid)
+ xact_ai->deleting_subid = isCommit ? parentSubid : InvalidSubTransactionId;
+ }
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
@@ -438,7 +632,7 @@ get_session_variable(Oid varid)
validated_lxid != MyProc->vxid.lxid)
{
/* free the memory from dropped session variables */
- remove_invalid_session_variables();
+ remove_invalid_session_variables(false);
/* don't repeat the above step in the same transaction */
validated_lxid = MyProc->vxid.lxid;
@@ -534,7 +728,7 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
validated_lxid != MyProc->vxid.lxid)
{
/* free the memory from dropped session variables */
- remove_invalid_session_variables();
+ remove_invalid_session_variables(false);
/* don't repeat the above step in the same transaction */
validated_lxid = MyProc->vxid.lxid;
diff --git a/src/backend/commands/view.c b/src/backend/commands/view.c
index 6f0301555e0..6bef9a2612a 100644
--- a/src/backend/commands/view.c
+++ b/src/backend/commands/view.c
@@ -484,7 +484,7 @@ DefineView(ViewStmt *stmt, const char *queryString,
*/
view = copyObject(stmt->view); /* don't corrupt original command */
if (view->relpersistence == RELPERSISTENCE_PERMANENT
- && isQueryUsingTempRelation(viewParse))
+ && isQueryUsingTempObject(viewParse))
{
view->relpersistence = RELPERSISTENCE_TEMP;
ereport(NOTICE,
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 725f678e2fa..c0c3abd7a0e 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -3491,10 +3491,10 @@ transformCreateTableAsStmt(ParseState *pstate, CreateTableAsStmt *stmt)
* creation query. It would be hard to refresh data or incrementally
* maintain it if a source disappeared.
*/
- if (isQueryUsingTempRelation(query))
+ if (isQueryUsingTempObject(query))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("materialized views must not use temporary tables or views")));
+ errmsg("materialized views must not use temporary tables, views or session variables")));
/*
* A materialized view would either need to save parameters for use in
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index b5bd1093572..2af037d2669 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -473,6 +473,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <ival> OptTemp
%type <ival> OptNoLog
%type <oncommit> OnCommitOption
+%type <ival> XactEndActionOption
%type <ival> for_locking_strength
%type <node> for_locking_item
@@ -5263,26 +5264,39 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause
+ CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- n->variable = $3;
- n->typeName = $5;
- n->collClause = (CollateClause *) $6;
+ $4->relpersistence = $2;
+ n->variable = $4;
+ n->typeName = $6;
+ n->collClause = (CollateClause *) $7;
+ n->XactEndAction = $8;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause
+ | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- n->variable = $6;
- n->typeName = $8;
- n->collClause = (CollateClause *) $9;
+ $7->relpersistence = $2;
+ n->variable = $7;
+ n->typeName = $9;
+ n->collClause = (CollateClause *) $10;
+ n->XactEndAction = $11;
n->if_not_exists = true;
$$ = (Node *) n;
}
;
+/*
+ * Temporary session variables can be dropped on successful
+ * transaction end like tables.
+ */
+XactEndActionOption: ON COMMIT DROP { $$ = VARIABLE_XACTEND_DROP; }
+ | /*EMPTY*/ { $$ = VARIABLE_XACTEND_NOOP; }
+ ;
+
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index 04ecf64b1fc..bec6947ea2d 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -103,7 +103,7 @@ static void expandTupleDesc(TupleDesc tupdesc, Alias *eref,
static int specialAttNum(const char *attname);
static bool rte_visible_if_lateral(ParseState *pstate, RangeTblEntry *rte);
static bool rte_visible_if_qualified(ParseState *pstate, RangeTblEntry *rte);
-static bool isQueryUsingTempRelation_walker(Node *node, void *context);
+static bool isQueryUsingTempObject_walker(Node *node, void *context);
/*
@@ -3927,13 +3927,13 @@ rte_visible_if_qualified(ParseState *pstate, RangeTblEntry *rte)
* the query is a temporary relation (table, view, or materialized view).
*/
bool
-isQueryUsingTempRelation(Query *query)
+isQueryUsingTempObject(Query *query)
{
- return isQueryUsingTempRelation_walker((Node *) query, NULL);
+ return isQueryUsingTempObject_walker((Node *) query, NULL);
}
static bool
-isQueryUsingTempRelation_walker(Node *node, void *context)
+isQueryUsingTempObject_walker(Node *node, void *context)
{
if (node == NULL)
return false;
@@ -3959,13 +3959,23 @@ isQueryUsingTempRelation_walker(Node *node, void *context)
}
return query_tree_walker(query,
- isQueryUsingTempRelation_walker,
+ isQueryUsingTempObject_walker,
context,
QTW_IGNORE_JOINALIASES);
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ if (isAnyTempNamespace(get_session_variable_namespace(p->paramvarid)))
+ return true;
+ }
+ }
return expression_tree_walker(node,
- isQueryUsingTempRelation_walker,
+ isQueryUsingTempObject_walker,
context);
}
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 576ac986ef9..a3fca34c7d7 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5351,12 +5351,16 @@ listVariables(const char *pattern, bool verbose)
" pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n"
" (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
" WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
- " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n",
+ " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
+ " CASE v.varxactendaction\n"
+ " WHEN 'd' THEN 'ON COMMIT DROP'\n"
+ " END as \"%s\"\n",
gettext_noop("Schema"),
gettext_noop("Name"),
gettext_noop("Type"),
gettext_noop("Collation"),
- gettext_noop("Owner"));
+ gettext_noop("Owner"),
+ gettext_noop("Transactional end action"));
if (verbose)
{
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index d9bb96ad318..86c2d5c3a66 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -3612,7 +3612,7 @@ match_previous_words(int pattern_id,
/* CREATE TABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete "CREATE TEMP/TEMPORARY" with the possible temp objects */
else if (TailMatches("CREATE", "TEMP|TEMPORARY"))
- COMPLETE_WITH("SEQUENCE", "TABLE", "VIEW");
+ COMPLETE_WITH("SEQUENCE", "TABLE", "VARIABLE", "VIEW");
/* Complete "CREATE UNLOGGED" with TABLE or SEQUENCE */
else if (TailMatches("CREATE", "UNLOGGED"))
COMPLETE_WITH("TABLE", "SEQUENCE");
@@ -3963,7 +3963,8 @@ match_previous_words(int pattern_id,
}
/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE VARIABLE <name> with AS */
- else if (TailMatches("CREATE", "VARIABLE", MatchAny))
+ else if (TailMatches("CREATE", "VARIABLE", MatchAny) ||
+ TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny))
COMPLETE_WITH("AS");
else if (TailMatches("VARIABLE", MatchAny, "AS"))
/* Complete CREATE VARIABLE <name> with AS types */
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 5b45be5afaf..0fc672bc2ba 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -56,6 +56,9 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* typmod for variable's type */
int32 vartypmod BKI_DEFAULT(-1);
+ /* action on transaction end */
+ char varxactendaction BKI_DEFAULT(n);
+
/* variable collation */
Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation);
@@ -68,6 +71,12 @@ CATALOG(pg_variable,9222,VariableRelationId)
#endif
} FormData_pg_variable;
+typedef enum VariableXactEndAction
+{
+ VARIABLE_XACTEND_NOOP = 'n', /* NOOP */
+ VARIABLE_XACTEND_DROP = 'd', /* ON COMMIT DROP */
+} VariableXactEndAction;
+
/* ----------------
* Form_pg_variable corresponds to a pointer to a tuple with
* the format of the pg_variable relation.
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index d3cc79b5608..4492bee6d69 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -21,7 +21,11 @@
#include "tcop/cmdtag.h"
#include "utils/queryenvironment.h"
-extern void SessionVariableDropPostprocess(Oid varid);
+extern void SessionVariableCreatePostprocess(Oid varid, char XactEndAction);
+extern void SessionVariableDropPostprocess(Oid varid, char XactEndAction);
+extern void AtPreEOXact_SessionVariables(bool isCommit);
+extern void AtEOSubXact_SessionVariables(bool isCommit, SubTransactionId mySubid,
+ SubTransactionId parentSubid);
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index d5f00cf3702..04d4a853a3c 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3535,6 +3535,7 @@ typedef struct CreateSessionVarStmt
TypeName *typeName; /* the type of variable */
CollateClause *collClause;
bool if_not_exists; /* do nothing if it already exists */
+ char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 98b9285a54b..34d051ec98a 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -52,7 +52,9 @@ typedef struct Alias
List *colnames; /* optional list of column aliases */
} Alias;
-/* What to do at commit time for temporary relations */
+/*
+ * What to do at commit time for temporary relations or session variables.
+ */
typedef enum OnCommitAction
{
ONCOMMIT_NOOP, /* No ON COMMIT clause (do nothing) */
diff --git a/src/include/parser/parse_relation.h b/src/include/parser/parse_relation.h
index 3ece5cd4eef..3529bfa5b30 100644
--- a/src/include/parser/parse_relation.h
+++ b/src/include/parser/parse_relation.h
@@ -127,6 +127,6 @@ extern int attnameAttNum(Relation rd, const char *attname, bool sysColOK);
extern const NameData *attnumAttName(Relation rd, int attid);
extern Oid attnumTypeId(Relation rd, int attid);
extern Oid attnumCollationId(Relation rd, int attid);
-extern bool isQueryUsingTempRelation(Query *query);
+extern bool isQueryUsingTempObject(Query *query);
#endif /* PARSE_RELATION_H */
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
index 0a5579dc7ce..a609797dc5d 100644
--- a/src/test/isolation/expected/session-variable.out
+++ b/src/test/isolation/expected/session-variable.out
@@ -86,10 +86,11 @@ myvar
step sr1: ROLLBACK;
-starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+starting permutation: create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
step create3: CREATE VARIABLE myvar3 AS text;
step let3: LET myvar3 = 'test';
step s3: BEGIN;
+step o_c_d: CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP;
step create4: CREATE VARIABLE myvar4 AS text;
step let4: LET myvar4 = 'test';
step drop4: DROP VARIABLE myvar4;
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
index c864fee4006..45e65d4085d 100644
--- a/src/test/isolation/specs/session-variable.spec
+++ b/src/test/isolation/specs/session-variable.spec
@@ -24,6 +24,7 @@ step create { CREATE VARIABLE myvar AS text; }
session s3
step s3 { BEGIN; }
step let3 { LET myvar3 = 'test'; }
+step o_c_d { CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP; }
step create4 { CREATE VARIABLE myvar4 AS text; }
step let4 { LET myvar4 = 'test'; }
step drop4 { DROP VARIABLE myvar4; }
@@ -47,4 +48,4 @@ permutation let val dbg drop create dbg val
# calling the dbg step after the concurrent drop
permutation let val s1 dbg drop create dbg val sr1
# test for DISCARD ALL when all internal queues have actions registered
-permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+permutation create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 0c48fdfaf61..3ddbcc7cc2a 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6020,20 +6020,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Access privileges | Description
---------+------+-------------------+-----------+------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Access privileges | Description
---------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6501,9 +6501,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner
---------+------+------+-----------+-------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action
+--------+------+------+-----------+-------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6676,9 +6676,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner
---------+------+------+-----------+-------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action
+--------+------+------+-----------+-------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6815,9 +6815,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner
---------+------+------+-----------+-------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action
+--------+------+------+-----------+-------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 6049f689f24..14e093eb8a7 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2145,3 +2145,123 @@ SELECT var1;
DEALLOCATE p1;
DROP VARIABLE var1;
+-- temporary variables
+CREATE TEMP VARIABLE var1 AS int;
+-- this view should be temporary
+CREATE VIEW var_test_view AS SELECT var1;
+NOTICE: view "var_test_view" will be a temporary view
+DROP VARIABLE var1 CASCADE;
+NOTICE: drop cascades to view var_test_view
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+ROLLBACK;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ ROLLBACK TO s1;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 18b59fc9cad..e6ccc37153d 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1312,6 +1312,7 @@ BEGIN;
DROP VARIABLE var1;
SELECT var2;
ROLLBACK;
+
-- should be ok
SELECT var1;
@@ -1479,3 +1480,68 @@ SELECT var1;
DEALLOCATE p1;
DROP VARIABLE var1;
+
+-- temporary variables
+CREATE TEMP VARIABLE var1 AS int;
+-- this view should be temporary
+CREATE VIEW var_test_view AS SELECT var1;
+
+DROP VARIABLE var1 CASCADE;
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+ROLLBACK;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+ROLLBACK;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ ROLLBACK TO s1;
+ SELECT var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 95c7a892f97..a2147df28b3 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2818,6 +2818,7 @@ SupportRequestWFuncMonotonic
SVariable
SVariableData
SVariableState
+SVariableXActDropItem
Syn
SyncOps
SyncRepConfigData
--
2.48.1
[text/x-patch] v20250216-0015-allow-read-an-value-of-session-variable-directly-fro.patch (15.1K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/14-v20250216-0015-allow-read-an-value-of-session-variable-directly-fro.patch)
download | inline diff:
From 9278edcc5aa7af81d7e26df0d00c26df623b6096 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:07:03 +0100
Subject: [PATCH 15/21] allow read an value of session variable directly from
expression executor
The expression executor can be called directly (not inside query executor)
when expression is evaluated as simple expression in plpgsql or when expression
is an argument of CALL or EXECUTE statements. For these cases we need to allow direct
access to content of session variables from executor. We can do it, because
we know so the expression is not evaluated under query and cannot be
evaluated inside parallel worker.
This patch enables session variables for simple expression evaluation.
This patch enables usage session variables in arguments of CALL stmt.
---
src/backend/commands/prepare.c | 10 ---
src/backend/executor/execExpr.c | 86 +++++++++++++++----
src/backend/executor/execExprInterp.c | 14 +++
src/backend/jit/llvm/llvmjit_expr.c | 6 ++
src/backend/parser/analyze.c | 10 ---
src/include/executor/execExpr.h | 11 ++-
.../src/expected/plpgsql_session_variable.out | 3 +-
src/pl/plpgsql/src/pl_exec.c | 3 +-
.../regress/expected/session_variables.out | 38 ++++----
src/test/regress/sql/session_variables.sql | 12 +--
10 files changed, 125 insertions(+), 68 deletions(-)
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 4ea2bfea4ea..70f03099996 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -338,16 +338,6 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
i++;
}
- /*
- * The arguments of EXECUTE are evaluated by a direct expression
- * executor call. This mode doesn't support session variables yet.
- * It will be enabled later.
- */
- if (pstate->p_hasSessionVariables)
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("session variable cannot be used as an argument")));
-
/* Prepare the expressions for execution */
exprstates = ExecPrepareExprList(params, estate);
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 270e6d344be..d07377948a0 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -34,6 +34,8 @@
#include "catalog/objectaccess.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
#include "executor/execExpr.h"
#include "executor/nodeSubplan.h"
#include "funcapi.h"
@@ -1054,22 +1056,74 @@ ExecInitExprRec(Expr *node, ExprState *state,
es_num_session_variables = state->parent->state->es_num_session_variables;
}
- Assert(es_session_variables);
-
- /* parameter sanity checks */
- if (param->paramid >= es_num_session_variables)
- elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
-
- var = &es_session_variables[param->paramid];
-
- /*
- * In this case, pass the value like a
- * constant.
- */
- scratch.opcode = EEOP_CONST;
- scratch.d.constval.value = var->value;
- scratch.d.constval.isnull = var->isnull;
- ExprEvalPushStep(state, &scratch);
+ if (es_session_variables)
+ {
+ /*
+ * This path is used when expression is
+ * evaluated inside query evaluation. For
+ * ensuring of immutability of session variable
+ * inside query we use special buffer with copy
+ * of used session variables. This method helps
+ * with parallel execution too.
+ */
+
+ /* parameter sanity checks */
+ if (param->paramid >= es_num_session_variables)
+ elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
+
+ var = &es_session_variables[param->paramid];
+
+ /*
+ * In this case, pass the value like a
+ * constant.
+ */
+ scratch.opcode = EEOP_CONST;
+ scratch.d.constval.value = var->value;
+ scratch.d.constval.isnull = var->isnull;
+ ExprEvalPushStep(state, &scratch);
+ }
+ else
+ {
+ Oid varid = param->paramvarid;
+
+ Assert(!IsParallelWorker());
+
+ /*
+ * In some cases (plpgsql's simple expression
+ * evaluation or evaluation of CALL arguments),
+ * the expression executor is called directly.
+ * We can allow direct access to session
+ * variables (copy only), because we know, so
+ * outside is not any query (and expression
+ * cannot be executed parallel).
+ *
+ * In this case we should to do aclcheck,
+ * because usual aclcheck from
+ * standard_ExecutorStart is not executed in
+ * this case. Fortunately it is just once per
+ * transaction.
+ *
+ * Don't do permission check, when variable is
+ * used like base node for assignment indirection.
+ */
+ if (!param->parambasenode)
+ {
+ AclResult aclresult;
+
+ aclresult = object_aclcheck(
+ VariableRelationId, varid,
+ GetUserId(), ACL_SELECT);
+
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult,
+ OBJECT_VARIABLE,
+ get_session_variable_name(varid));
+ }
+
+ scratch.opcode = EEOP_PARAM_VARIABLE;
+ scratch.d.vparam.varid = varid;
+ ExprEvalPushStep(state, &scratch);
+ }
}
break;
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 1c3477b03c9..45ec7b58610 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -59,6 +59,7 @@
#include "access/heaptoast.h"
#include "catalog/pg_type.h"
#include "commands/sequence.h"
+#include "commands/session_variable.h"
#include "executor/execExpr.h"
#include "executor/nodeSubplan.h"
#include "funcapi.h"
@@ -521,6 +522,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
&&CASE_EEOP_PARAM_EXEC,
&&CASE_EEOP_PARAM_EXTERN,
&&CASE_EEOP_PARAM_CALLBACK,
+ &&CASE_EEOP_PARAM_VARIABLE,
&&CASE_EEOP_PARAM_SET,
&&CASE_EEOP_CASE_TESTVAL,
&&CASE_EEOP_CASE_TESTVAL_EXT,
@@ -1265,6 +1267,18 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
EEO_NEXT();
}
+ EEO_CASE(EEOP_PARAM_VARIABLE)
+ {
+ /*
+ * Direct access to session variable (without buffering). Because
+ * returned value can be used (without an assignement) after the
+ * referenced session variables is updated, we have to use an copy
+ * of stored value every time.
+ */
+ *op->resvalue = GetSessionVariable(op->d.vparam.varid, op->resnull);
+ EEO_NEXT();
+ }
+
EEO_CASE(EEOP_PARAM_SET)
{
/* out of line, unlikely to matter performance-wise */
diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c
index f0f5c3bd49f..ad8d80cf49c 100644
--- a/src/backend/jit/llvm/llvmjit_expr.c
+++ b/src/backend/jit/llvm/llvmjit_expr.c
@@ -1208,6 +1208,12 @@ llvm_compile_expr(ExprState *state)
break;
}
+ case EEOP_PARAM_VARIABLE:
+ build_EvalXFunc(b, mod, "ExecEvalParamVariable",
+ v_state, op, v_econtext);
+ LLVMBuildBr(b, opblocks[opno + 1]);
+ break;
+
case EEOP_PARAM_SET:
build_EvalXFunc(b, mod, "ExecEvalParamSet",
v_state, op, v_econtext);
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index c0c3abd7a0e..46a22ff5c94 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -3571,16 +3571,6 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt)
true,
stmt->funccall->location);
- /*
- * The arguments of CALL statement are evaluated by a direct expression
- * executor call. This path is unsupported yet, so block it. It will be
- * enabled later.
- */
- if (pstate->p_hasSessionVariables)
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("session variable cannot be used as an argument")));
-
assign_expr_collations(pstate, node);
fexpr = castNode(FuncExpr, node);
diff --git a/src/include/executor/execExpr.h b/src/include/executor/execExpr.h
index 191d8fe34de..1259ef72bac 100644
--- a/src/include/executor/execExpr.h
+++ b/src/include/executor/execExpr.h
@@ -164,10 +164,11 @@ typedef enum ExprEvalOp
EEOP_BOOLTEST_IS_FALSE,
EEOP_BOOLTEST_IS_NOT_FALSE,
- /* evaluate PARAM_EXEC/EXTERN parameters */
+ /* evaluate PARAM_EXEC/EXTERN/VARIABLE parameters */
EEOP_PARAM_EXEC,
EEOP_PARAM_EXTERN,
EEOP_PARAM_CALLBACK,
+ EEOP_PARAM_VARIABLE,
/* set PARAM_EXEC value */
EEOP_PARAM_SET,
@@ -430,6 +431,12 @@ typedef struct ExprEvalStep
Oid paramtype; /* OID of parameter's datatype */
} cparam;
+ /* for EEOP_PARAM_VARIABLE */
+ struct
+ {
+ Oid varid; /* OID of assigned variable */
+ } vparam;
+
/* for EEOP_CASE_TESTVAL/DOMAIN_TESTVAL */
struct
{
@@ -852,6 +859,8 @@ extern void ExecEvalParamSet(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalParamExtern(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
+extern void ExecEvalParamVariable(ExprState *state, ExprEvalStep *op,
+ ExprContext *econtext);
extern void ExecEvalCoerceViaIOSafe(ExprState *state, ExprEvalStep *op);
extern void ExecEvalSQLValueFunction(ExprState *state, ExprEvalStep *op);
extern void ExecEvalCurrentOfExpr(ExprState *state, ExprEvalStep *op);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index a6523f7afe2..ecac64fcfb4 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -211,8 +211,7 @@ SET ROLE TO regress_var_exec_role;
-- should fail
SELECT var_read_func();
ERROR: permission denied for session variable plpgsql_sv_var1
-CONTEXT: PL/pgSQL expression "plpgsql_sv_var1"
-PL/pgSQL function var_read_func() line 3 at RAISE
+CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE
SET ROLE TO DEFAULT;
SET ROLE TO regress_var_owner_role;
GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index cb282404c1a..d4377ceecbf 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8264,8 +8264,7 @@ exec_is_simple_query(PLpgSQL_expr *expr)
query->sortClause ||
query->limitOffset ||
query->limitCount ||
- query->setOperations ||
- query->hasSessionVariables)
+ query->setOperations)
return false;
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 548c0e3bcd2..0ed2d5fbb01 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -483,8 +483,7 @@ ERROR: permission denied for session variable var1
CONTEXT: SQL function "sqlfx" statement 1
SELECT plpgsqlfx(20);
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "$1 + var1"
-PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
+CONTEXT: PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
-- should be ok
SELECT sqlfx_sd(20);
sqlfx_sd
@@ -780,27 +779,28 @@ $$;
NOTICE: result array: {1,2,3,4,5,6,7,8,9,10}
DROP VARIABLE var1;
DROP VARIABLE var2;
--- CALL statement is not supported yet
--- requires direct access to session variable from expression executor
+-- CALL statement is supported
CREATE VARIABLE v int;
+LET v = 1;
CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
--- should not crash (but is not supported yet)
+-- should to work
CALL p(v);
-ERROR: session variable cannot be used as an argument
+NOTICE: 1
DO $$ BEGIN CALL p(v); END $$;
-ERROR: session variable cannot be used as an argument
-CONTEXT: SQL statement "CALL p(v)"
-PL/pgSQL function inline_code_block line 1 at CALL
+NOTICE: 1
DROP PROCEDURE p(int);
DROP VARIABLE v;
--- EXECUTE statement is not supported yet
--- requires direct access to session variable from expression executor
+-- EXECUTE statement
CREATE VARIABLE v int;
LET v = 20;
PREPARE ptest(int) AS SELECT $1;
--- should fail
+-- should be ok
EXECUTE ptest(v);
-ERROR: session variable cannot be used as an argument
+ ?column?
+----------
+ 20
+(1 row)
+
DEALLOCATE ptest;
DROP VARIABLE v;
-- test search path
@@ -1123,12 +1123,10 @@ LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a
ERROR: permission denied for session variable var1
DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1.a"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
CONTEXT: SQL statement "LET var1.a = var1.a + 10"
@@ -1170,12 +1168,10 @@ LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a
ERROR: permission denied for session variable var1
DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1.a"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
CONTEXT: SQL statement "LET var1.a = var1.a + 10"
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 282ba5c8639..c8c2295adbd 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -548,13 +548,14 @@ $$;
DROP VARIABLE var1;
DROP VARIABLE var2;
--- CALL statement is not supported yet
--- requires direct access to session variable from expression executor
+-- CALL statement is supported
CREATE VARIABLE v int;
+LET v = 1;
+
CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
--- should not crash (but is not supported yet)
+-- should to work
CALL p(v);
DO $$ BEGIN CALL p(v); END $$;
@@ -562,13 +563,12 @@ DO $$ BEGIN CALL p(v); END $$;
DROP PROCEDURE p(int);
DROP VARIABLE v;
--- EXECUTE statement is not supported yet
--- requires direct access to session variable from expression executor
+-- EXECUTE statement
CREATE VARIABLE v int;
LET v = 20;
PREPARE ptest(int) AS SELECT $1;
--- should fail
+-- should be ok
EXECUTE ptest(v);
DEALLOCATE ptest;
--
2.48.1
[text/x-patch] v20250216-0014-Implementation-of-NOT-NULL-and-IMMUTABLE-clauses.patch (33.9K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/15-v20250216-0014-Implementation-of-NOT-NULL-and-IMMUTABLE-clauses.patch)
download | inline diff:
From 249b9eb5c15d1aaa3280c618e26a29a4f23abb03 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:05:06 +0100
Subject: [PATCH 14/21] Implementation of NOT NULL and IMMUTABLE clauses
Almost trivial patch - psql, pg_dump support
---
doc/src/sgml/catalogs.sgml | 20 +++
doc/src/sgml/plpgsql.sgml | 3 +-
doc/src/sgml/ref/create_variable.sgml | 32 +++-
src/backend/catalog/pg_variable.c | 8 +
src/backend/commands/session_variable.c | 69 ++++++++-
src/backend/parser/gram.y | 41 +++--
src/bin/pg_dump/pg_dump.c | 19 ++-
src/bin/pg_dump/pg_dump.h | 2 +
src/bin/pg_dump/t/002_pg_dump.pl | 36 +++++
src/bin/psql/describe.c | 6 +-
src/bin/psql/tab-complete.in.c | 12 +-
src/include/catalog/pg_variable.h | 6 +
src/include/nodes/parsenodes.h | 2 +
src/test/regress/expected/psql.out | 36 ++---
.../regress/expected/session_variables.out | 145 ++++++++++++++++++
src/test/regress/sql/session_variables.sql | 122 +++++++++++++++
16 files changed, 518 insertions(+), 41 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 27bdaf62668..c7a8170ddf2 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9867,6 +9867,26 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
<row>
<entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varnotnull</structfield> <type>boolean</type>
+ </para>
+ <para>
+ True if the session variable doesn't allow null values. The default value is false.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varisimmutable</structfield> <type>boolean</type>
+ </para>
+ <para>
+ True if the variable is <link linkend="sql-createvariable-immutable">immutable</link> (cannot be modified).
+ The default value is false.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vareoxaction</structfield> <type>char</type>
<structfield>varxactendaction</structfield> <type>char</type>
</para>
<para>
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index bfbff9ab74e..e704e05a991 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -6044,7 +6044,8 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE;
You can consider translating an Oracle package into a schema in
<productname>PostgreSQL</productname>. Package functions and procedures
would then become functions and procedures in that schema, and package
- variables could be translated to session variables in that schema.
+ variables could be translated to session variables or immutable session
+ variables in that schema.
(see <xref linkend="ddl-session-variables"/>).
</para>
</sect3>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index e4d8851ccb8..3c3e6d55b69 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -26,8 +26,8 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
- [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
+CREATE [ { TEMPORARY | TEMP } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+ [ NOT NULL ] [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -65,6 +65,22 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
<variablelist>
+ <varlistentry id="sql-createvariable-immutable">
+ <term><literal>IMMUTABLE</literal></term>
+ <listitem>
+ <para>
+ The assigned value of the session variable can not be changed.
+ Only if the session variable doesn't have a default value, a single
+ initialization is allowed using the <command>LET</command> command. Once
+ done, no further change is allowed until end of transaction
+ if the session variable was created with clause <literal>ON TRANSACTION
+ END RESET</literal>, or until reset of all session variables by
+ <command>DISCARD VARIABLES</command>, or until reset of all session
+ objects by command <command>DISCARD ALL</command>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createvariable-if-not-exists">
<term><literal>IF NOT EXISTS</literal></term>
<listitem>
@@ -105,6 +121,18 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-not-null">
+ <term><literal>NOT NULL</literal></term>
+ <listitem>
+ <para>
+ The <literal>NOT NULL</literal> clause forbids setting the session
+ variable to a null value. A session variable created as NOT NULL
+ should not to have a declared default value, and if the variable
+ has not assigned value, then the reading of this variable fails.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createvariable-default">
<term><literal>DEFAULT <replaceable>default_expr</replaceable></literal></term>
<listitem>
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 8fba4cc493b..0b6093a00ba 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -40,6 +40,8 @@ static ObjectAddress create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ bool not_null,
+ bool is_immutable,
Node *varDefexpr,
VariableXactEndAction varXactEndAction);
@@ -55,6 +57,8 @@ create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ bool not_null,
+ bool is_immutable,
Node *varDefexpr,
VariableXactEndAction varXactEndAction)
{
@@ -117,6 +121,8 @@ create_variable(const char *varName,
values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+ values[Anum_pg_variable_varnotnull - 1] = BoolGetDatum(not_null);
+ values[Anum_pg_variable_varisimmutable - 1] = BoolGetDatum(is_immutable);
values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
if (varDefexpr)
@@ -259,6 +265,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
varowner,
collation,
stmt->if_not_exists,
+ stmt->not_null,
+ stmt->is_immutable,
cooked_default,
stmt->XactEndAction);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 40275abfa7e..5d907eff60a 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -84,6 +84,9 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ bool not_null;
+ bool is_immutable;
+
bool reset_at_eox;
/*
@@ -102,6 +105,9 @@ typedef struct SVariableData
bool is_valid;
uint32 hashvalue; /* used for pairing sinval message */
+
+ /* true, when the value is already set, and cannot be changed more */
+ bool protect_value;
} SVariableData;
typedef SVariableData *SVariable;
@@ -563,6 +569,23 @@ eval_assign_defexpr(SVariable svar, HeapTuple tup)
MemoryContextSwitchTo(oldcxt);
}
+ else
+ {
+ /*
+ * Raise an error if this is a NOT NULL variable but the result of
+ * DEFAULT expression is NULL.
+ */
+ if (svar->not_null)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("null value is not allowed for NOT NULL session variable \"%s.%s\"",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid)),
+ errdetail("The result of DEFAULT expression is NULL.")));
+ }
+
+ if (svar->is_immutable)
+ svar->protect_value = true;
FreeExecutorState(estate);
}
@@ -593,6 +616,9 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval);
+ svar->not_null = varform->varnotnull;
+ svar->is_immutable = varform->varisimmutable;
+
svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
@@ -622,9 +648,31 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
ObjectIdGetDatum(varid));
- if (!is_write)
+ svar->protect_value = false;
+
+ /*
+ * When the variable is marked as IMMUTABLE, we prefer to evaluate
+ * possible DEFAULT before write op. In this case we want to protect
+ * default value against any overwrite.
+ */
+ if (!is_write ||
+ svar->is_immutable)
+ {
eval_assign_defexpr(svar, tup);
+ /*
+ * Raise an error if this is a NOT NULL variable without default
+ * expression.
+ */
+ if (svar->isnull && svar->not_null)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("null value is not allowed for NOT NULL session variable \"%s.%s\"",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ errdetail("The session variable was not initialized yet.")));
+ }
+
ReleaseSysCache(tup);
}
@@ -644,6 +692,21 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
Assert(svar);
Assert(!isnull || value == (Datum) 0);
+ if (svar->protect_value)
+ ereport(ERROR,
+ (errcode(ERRCODE_ERROR_IN_ASSIGNMENT),
+ errmsg("session variable \"%s.%s\" is declared IMMUTABLE",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid))));
+
+ /* don't allow assignment of null to NOT NULL variable */
+ if (isnull && svar->not_null)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("null value is not allowed for NOT NULL session variable \"%s.%s\"",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid))));
+
/*
* Use typbyval, typbylen from session variable only when they are
* trustworthy (the invalidation message was not accepted for this
@@ -684,6 +747,10 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
svar->value = newval;
svar->isnull = isnull;
+
+ /* don't allow more changes of value when variable is IMMUTABLE */
+ if (svar->is_immutable)
+ svar->protect_value = true;
}
/*
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 1d10eb7c52c..11ae96a4397 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -675,6 +675,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
json_object_constructor_null_clause_opt
json_array_constructor_null_clause_opt
+%type <boolean> OptNotNull OptImmutable
/*
* Non-keyword token types. These are hard-wired into the "flex" lexer.
@@ -5265,27 +5266,31 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
+ CREATE OptTemp OptImmutable VARIABLE qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $4->relpersistence = $2;
- n->variable = $4;
- n->typeName = $6;
- n->collClause = (CollateClause *) $7;
- n->defexpr = $8;
- n->XactEndAction = $9;
+ $5->relpersistence = $2;
+ n->is_immutable = $3;
+ n->variable = $5;
+ n->typeName = $7;
+ n->collClause = (CollateClause *) $8;
+ n->not_null = $9;
+ n->defexpr = $10;
+ n->XactEndAction = $11;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
+ | CREATE OptTemp OptImmutable VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $7->relpersistence = $2;
- n->variable = $7;
- n->typeName = $9;
- n->collClause = (CollateClause *) $10;
- n->defexpr = $11;
- n->XactEndAction = $12;
+ $8->relpersistence = $2;
+ n->is_immutable = $3;
+ n->variable = $8;
+ n->typeName = $10;
+ n->collClause = (CollateClause *) $11;
+ n->not_null = $12;
+ n->defexpr = $13;
+ n->XactEndAction = $14;
n->if_not_exists = true;
$$ = (Node *) n;
}
@@ -5305,6 +5310,14 @@ XactEndActionOption: ON COMMIT DROP { $$ = VARIABLE_XACTEND_DROP; }
;
+OptNotNull: NOT NULL_P { $$ = true; }
+ | /* EMPTY */ { $$ = false; }
+ ;
+
+OptImmutable: IMMUTABLE { $$ = true; }
+ | /* EMPTY */ { $$ = false; }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index b777ef967b6..47c26947c4d 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5444,6 +5444,8 @@ getVariables(Archive *fout)
int i_varxactendaction;
int i_varowner;
int i_varcollation;
+ int i_varnotnull;
+ int i_varisimmutable;
int i_varacl;
int i_acldefault;
int i,
@@ -5464,6 +5466,8 @@ getVariables(Archive *fout)
" THEN v.varcollation\n"
" ELSE 0\n"
" END AS varcollation,\n"
+ " v.varnotnull,\n"
+ " v.varisimmutable,\n"
" pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n"
" v.varowner, v.varacl,\n"
" acldefault('V', v.varowner) AS acldefault\n"
@@ -5484,6 +5488,8 @@ getVariables(Archive *fout)
i_vardefexpr = PQfnumber(res, "vardefexpr");
i_varxactendaction = PQfnumber(res, "varxactendaction");
i_varcollation = PQfnumber(res, "varcollation");
+ i_varnotnull = PQfnumber(res, "varnotnull");
+ i_varisimmutable = PQfnumber(res, "varisimmutable");
i_varowner = PQfnumber(res, "varowner");
i_varacl = PQfnumber(res, "varacl");
@@ -5510,6 +5516,8 @@ getVariables(Archive *fout)
pg_strdup(PQgetvalue(res, i, i_varxactendaction));
varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
+ varinfo[i].varnotnull = *(PQgetvalue(res, i, i_varnotnull)) == 't';
+ varinfo[i].varisimmutable = *(PQgetvalue(res, i, i_varisimmutable)) == 't';
varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
@@ -5556,7 +5564,9 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
const char *vartypname;
const char *vardefexpr;
const char *varxactendaction;
+ const char *varisimmutable;
Oid varcollation;
+ bool varnotnull;
/* skip if not to be dumped */
if (!varinfo->dobj.dump || !dopt->dumpSchema)
@@ -5570,12 +5580,14 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
vardefexpr = varinfo->vardefexpr;
varxactendaction = varinfo->varxactendaction;
varcollation = varinfo->varcollation;
+ varnotnull = varinfo->varnotnull;
+ varisimmutable = varinfo->varisimmutable ? "IMMUTABLE " : "";
appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
qualvarname);
- appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s",
- qualvarname, vartypname);
+ appendPQExpBuffer(query, "CREATE %sVARIABLE %s AS %s",
+ varisimmutable, qualvarname, vartypname);
if (OidIsValid(varcollation))
{
@@ -5587,6 +5599,9 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
fmtQualifiedDumpable(coll));
}
+ if (varnotnull)
+ appendPQExpBuffer(query, " NOT NULL");
+
if (vardefexpr)
appendPQExpBuffer(query, " DEFAULT %s",
vardefexpr);
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index ef1ba042132..0ae406f8551 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -722,6 +722,8 @@ typedef struct _VariableInfo
char *varxactendaction;
Oid varcollation;
const char *rolname; /* name of owner, or empty string */
+ bool varnotnull;
+ bool varisimmutable;
} VariableInfo;
/*
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index fb25f80a852..5f80bd4e79a 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4108,6 +4108,42 @@ my %tests = (
},
},
+ 'CREATE IMMUTABLE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE IMMUTABLE VARIABLE dump_test.variable5 AS integer',
+ regexp => qr/^
+ \QCREATE IMMUTABLE VARIABLE dump_test.variable5 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
+ 'CREATE IMMUTABLE VARIABLE test_variable NOT NULL DEFAULT' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE IMMUTABLE VARIABLE dump_test.variable7 AS integer NOT NULL DEFAULT 10',
+ regexp => qr/^
+ \QCREATE IMMUTABLE VARIABLE dump_test.variable7 AS integer NOT NULL DEFAULT 10;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index b5e5d073f9c..07835aa2bab 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5352,6 +5352,8 @@ listVariables(const char *pattern, bool verbose)
" (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
" WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
+ " NOT v.varnotnull as \"%s\",\n"
+ " NOT v.varisimmutable as \"%s\",\n"
" pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
@@ -5362,6 +5364,8 @@ listVariables(const char *pattern, bool verbose)
gettext_noop("Type"),
gettext_noop("Collation"),
gettext_noop("Owner"),
+ gettext_noop("Nullable"),
+ gettext_noop("Mutable"),
gettext_noop("Default"),
gettext_noop("Transactional end action"));
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 86c2d5c3a66..f547bce1a10 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1273,6 +1273,8 @@ static const pgsql_thing_t words_after_create[] = {
{"FOREIGN TABLE", NULL, NULL, NULL},
{"FUNCTION", NULL, NULL, Query_for_list_of_functions},
{"GROUP", Query_for_list_of_roles},
+ {"IMMUTABLE VARIABLE", NULL, NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE IMMUTABLE
+ * VARIABLE ... */
{"INDEX", NULL, NULL, &Query_for_list_of_indexes},
{"LANGUAGE", Query_for_list_of_languages},
{"LARGE OBJECT", NULL, NULL, NULL, NULL, THING_NO_CREATE | THING_NO_DROP},
@@ -3612,7 +3614,8 @@ match_previous_words(int pattern_id,
/* CREATE TABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete "CREATE TEMP/TEMPORARY" with the possible temp objects */
else if (TailMatches("CREATE", "TEMP|TEMPORARY"))
- COMPLETE_WITH("SEQUENCE", "TABLE", "VARIABLE", "VIEW");
+ COMPLETE_WITH("IMMUTABLE VARIABLE", "SEQUENCE", "TABLE", "VARIABLE",
+ "VIEW");
/* Complete "CREATE UNLOGGED" with TABLE or SEQUENCE */
else if (TailMatches("CREATE", "UNLOGGED"))
COMPLETE_WITH("TABLE", "SEQUENCE");
@@ -3964,7 +3967,8 @@ match_previous_words(int pattern_id,
/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE VARIABLE <name> with AS */
else if (TailMatches("CREATE", "VARIABLE", MatchAny) ||
- TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny))
+ TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny) ||
+ TailMatches("IMMUTABLE", "VARIABLE", MatchAny))
COMPLETE_WITH("AS");
else if (TailMatches("VARIABLE", MatchAny, "AS"))
/* Complete CREATE VARIABLE <name> with AS types */
@@ -4624,6 +4628,10 @@ match_previous_words(int pattern_id,
else if (TailMatches("FROM", "SERVER", MatchAny, "INTO", MatchAny))
COMPLETE_WITH("OPTIONS (");
+/* IMMUTABLE -- can be expend to IMMUTABLE VARIABLE */
+ else if (TailMatches("CREATE", "IMMUTABLE"))
+ COMPLETE_WITH("VARIABLE");
+
/* INSERT --- can be inside EXPLAIN, RULE, etc */
/* Complete NOT MATCHED THEN INSERT */
else if (TailMatches("NOT", "MATCHED", "THEN", "INSERT"))
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 09dd44a44e1..cf21e0426a7 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -56,6 +56,12 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* typmod for variable's type */
int32 vartypmod BKI_DEFAULT(-1);
+ /* don't allow NULL */
+ bool varnotnull BKI_DEFAULT(f);
+
+ /* don't allow changes */
+ bool varisimmutable BKI_DEFAULT(f);
+
/* action on transaction end */
char varxactendaction BKI_DEFAULT(n);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index d1d2ac91fb5..6bcaf480576 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3535,6 +3535,8 @@ typedef struct CreateSessionVarStmt
TypeName *typeName; /* the type of variable */
CollateClause *collClause;
bool if_not_exists; /* do nothing if it already exists */
+ bool not_null; /* disallow nulls */
+ bool is_immutable; /* don't allow changes */
Node *defexpr; /* default expression */
char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 999fc88d1e1..78aca67e452 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6020,20 +6020,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+---------+--------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | | | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+---------+--------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | | | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6501,9 +6501,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action
---------+------+------+-----------+-------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6676,9 +6676,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action
---------+------+------+-----------+-------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6815,9 +6815,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action
---------+------+------+-----------+-------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 5640875dc59..548c0e3bcd2 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2362,3 +2362,148 @@ SELECT var1;
DROP VARIABLE var1;
DROP FUNCTION vartest_fx();
+-- test NOT NULL
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL;
+-- should to fail
+SELECT var1;
+ERROR: null value is not allowed for NOT NULL session variable "public.var1"
+DETAIL: The session variable was not initialized yet.
+--should be ok
+LET var1 = 10;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1;
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT 0;
+--should be ok
+SELECT var1;
+ var1
+------
+ 0
+(1 row)
+
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DISCARD VARIABLES;
+-- should to fail
+LET var1 = NULL;
+ERROR: null value is not allowed for NOT NULL session variable "public.var1"
+DROP VARIABLE var1;
+-- test NOT NULL
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN NULL;
+END;
+$$ LANGUAGE plpgsql;
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT vartest_fx();
+-- should to fail
+SELECT var1;
+ERROR: null value is not allowed for NOT NULL session variable "public.var1"
+DETAIL: The result of DEFAULT expression is NULL.
+DISCARD VARIABLES;
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+DISCARD VARIABLES;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 0
+(1 row)
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
+-- test IMMUTBLE
+CREATE IMMUTABLE VARIABLE var1 AS int;
+-- should be ok
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+-- first write should ok
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DISCARD VARIABLES;
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DISCARD VARIABLES;
+-- should be ok
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+-- should be ok
+LET var1 = NULL;
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DROP VARIABLE var1;
+CREATE IMMUTABLE VARIABLE var1 AS int DEFAULT 10;
+-- don't allow change when variable has DEFAULT value
+-- should to fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DISCARD VARIABLES;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DROP VARIABLE var1;
+-- should be ok
+CREATE IMMUTABLE VARIABLE var1 AS INT NOT NULL DEFAULT 10;
+-- should to fail
+LET var1 = 10;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- should to fail
+LET var1 = 30;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DROP VARIABLE var1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 2c7388639d9..282ba5c8639 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1613,3 +1613,125 @@ SELECT var1;
DROP VARIABLE var1;
DROP FUNCTION vartest_fx();
+
+-- test NOT NULL
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL;
+-- should to fail
+SELECT var1;
+
+--should be ok
+LET var1 = 10;
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT 0;
+
+--should be ok
+SELECT var1;
+
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+
+DISCARD VARIABLES;
+
+-- should to fail
+LET var1 = NULL;
+
+DROP VARIABLE var1;
+
+-- test NOT NULL
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN NULL;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT vartest_fx();
+
+-- should to fail
+SELECT var1;
+
+DISCARD VARIABLES;
+
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+
+DISCARD VARIABLES;
+
+-- should be ok
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
+
+-- test IMMUTBLE
+CREATE IMMUTABLE VARIABLE var1 AS int;
+
+-- should be ok
+SELECT var1;
+-- first write should ok
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+
+DISCARD VARIABLES;
+
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+
+DISCARD VARIABLES;
+
+-- should be ok
+SELECT var1;
+-- should be ok
+LET var1 = NULL;
+-- should fail
+LET var1 = 20;
+
+DROP VARIABLE var1;
+
+CREATE IMMUTABLE VARIABLE var1 AS int DEFAULT 10;
+
+-- don't allow change when variable has DEFAULT value
+-- should to fail
+LET var1 = 20;
+
+DISCARD VARIABLES;
+
+-- should be ok
+SELECT var1;
+-- should fail
+LET var1 = 20;
+
+DROP VARIABLE var1;
+
+-- should be ok
+CREATE IMMUTABLE VARIABLE var1 AS INT NOT NULL DEFAULT 10;
+
+-- should to fail
+LET var1 = 10;
+LET var1 = 20;
+
+-- should be ok
+SELECT var1;
+
+-- should to fail
+LET var1 = 30;
+
+DROP VARIABLE var1;
--
2.48.1
[text/x-patch] v20250216-0016-allow-parallel-execution-queries-with-session-variab.patch (15.8K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/16-v20250216-0016-allow-parallel-execution-queries-with-session-variab.patch)
download | inline diff:
From cbe4c9261946da39d920b66fb9a42d597edff672 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:08:17 +0100
Subject: [PATCH 16/21] allow parallel execution queries with session variables
---
doc/src/sgml/parallel.sgml | 6 -
src/backend/commands/session_variable.c | 23 +++
src/backend/executor/execMain.c | 20 ++-
src/backend/executor/execParallel.c | 147 +++++++++++++++++-
src/backend/optimizer/util/clauses.c | 18 +--
src/backend/tcop/pquery.c | 3 +
src/include/commands/session_variable.h | 1 +
src/include/executor/execdesc.h | 4 +
src/include/nodes/execnodes.h | 1 +
.../regress/expected/session_variables.out | 12 +-
10 files changed, 206 insertions(+), 29 deletions(-)
diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index 683dede6adc..1ce9abf86f5 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -515,12 +515,6 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
Plan nodes that reference a correlated <literal>SubPlan</literal>.
</para>
</listitem>
-
- <listitem>
- <para>
- Plan nodes that use a session variable.
- </para>
- </listitem>
</itemizedlist>
<sect2 id="parallel-labeling">
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 5d907eff60a..367751ed344 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -991,6 +991,29 @@ GetSessionVariable(Oid varid, bool *isNull)
return copy_session_variable_value(svar, isNull);
}
+/*
+ * Returns a copy of the value of the session variable (in the current memory
+ * context) plus typid of the session variable. The caller is responsible for
+ * permission checks.
+ */
+Datum
+GetSessionVariableWithTypeid(Oid varid, bool *isNull, Oid *typid)
+{
+ SVariable svar;
+
+ svar = get_session_variable(varid);
+
+ *typid = svar->typid;
+
+ /*
+ * Although "svar" is freshly validated in this point, svar->is_valid can
+ * be false, if an invalidation message was processed during the domain check.
+ * But the variable and all its dependencies are locked now, so we don't need
+ * to repeat the validation.
+ */
+ return copy_session_variable_value(svar, isNull);
+}
+
/*
* Assign the result of the evaluated expression to the session variable
*/
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 35f89dc4212..883517e7b9d 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -211,7 +211,19 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
* be changed inside query execution time, and then a reference to
* previously returned value can be corrupted).
*/
- if (queryDesc->plannedstmt->sessionVariables)
+ if (queryDesc->num_session_variables > 0)
+ {
+ /*
+ * When a parallel query needs to access query parameters (including
+ * related session variables), then related session variables are
+ * restored (deserialized) in queryDesc already. So just push pointer
+ * of this array to executor's estate.
+ */
+ Assert(IsParallelWorker());
+ estate->es_session_variables = queryDesc->session_variables;
+ estate->es_num_session_variables = queryDesc->num_session_variables;
+ }
+ else if (queryDesc->plannedstmt->sessionVariables)
{
int nSessionVariables;
int i = 0;
@@ -250,9 +262,9 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
get_session_variable_name(varid));
}
- estate->es_session_variables[i].value =
- GetSessionVariable(varid,
- &estate->es_session_variables[i].isnull);
+ estate->es_session_variables[i].value = GetSessionVariableWithTypeid(varid,
+ &estate->es_session_variables[i].isnull,
+ &estate->es_session_variables[i].typid);
i++;
}
diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c
index 134ff62f5cb..dddc3bba0a0 100644
--- a/src/backend/executor/execParallel.c
+++ b/src/backend/executor/execParallel.c
@@ -12,8 +12,9 @@
* workers and ensuring that their state generally matches that of the
* leader; see src/backend/access/transam/README.parallel for details.
* However, we must save and restore relevant executor state, such as
- * any ParamListInfo associated with the query, buffer/WAL usage info, and
- * the actual plan to be passed down to the worker.
+ * any ParamListInfo associated with the query, buffer/WAL usage info,
+ * session variables buffer, and the actual plan to be passed down to
+ * the worker.
*
* IDENTIFICATION
* src/backend/executor/execParallel.c
@@ -64,6 +65,7 @@
#define PARALLEL_KEY_QUERY_TEXT UINT64CONST(0xE000000000000008)
#define PARALLEL_KEY_JIT_INSTRUMENTATION UINT64CONST(0xE000000000000009)
#define PARALLEL_KEY_WAL_USAGE UINT64CONST(0xE00000000000000A)
+#define PARALLEL_KEY_SESSION_VARIABLES UINT64CONST(0xE00000000000000B)
#define PARALLEL_TUPLE_QUEUE_SIZE 65536
@@ -138,6 +140,12 @@ static bool ExecParallelRetrieveInstrumentation(PlanState *planstate,
/* Helper function that runs in the parallel worker. */
static DestReceiver *ExecParallelGetReceiver(dsm_segment *seg, shm_toc *toc);
+/* Helper functions that can pass values of session variables */
+static Size EstimateSessionVariables(EState *estate);
+static void SerializeSessionVariables(EState *estate, char **start_address);
+static SessionVariableValue *RestoreSessionVariables(char **start_address,
+ int *num_session_variables);
+
/*
* Create a serialized representation of the plan to be sent to each worker.
*/
@@ -598,6 +606,7 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
char *pstmt_data;
char *pstmt_space;
char *paramlistinfo_space;
+ char *session_variables_space;
BufferUsage *bufusage_space;
WalUsage *walusage_space;
SharedExecutorInstrumentation *instrumentation = NULL;
@@ -607,6 +616,7 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
int instrumentation_len = 0;
int jit_instrumentation_len = 0;
int instrument_offset = 0;
+ int session_variables_len = 0;
Size dsa_minsize = dsa_minimum_size();
char *query_string;
int query_len;
@@ -662,6 +672,11 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
shm_toc_estimate_chunk(&pcxt->estimator, paramlistinfo_len);
shm_toc_estimate_keys(&pcxt->estimator, 1);
+ /* Estimate space for serialized session variables. */
+ session_variables_len = EstimateSessionVariables(estate);
+ shm_toc_estimate_chunk(&pcxt->estimator, session_variables_len);
+ shm_toc_estimate_keys(&pcxt->estimator, 1);
+
/*
* Estimate space for BufferUsage.
*
@@ -763,6 +778,11 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
shm_toc_insert(pcxt->toc, PARALLEL_KEY_PARAMLISTINFO, paramlistinfo_space);
SerializeParamList(estate->es_param_list_info, ¶mlistinfo_space);
+ /* Store serialized session variables. */
+ session_variables_space = shm_toc_allocate(pcxt->toc, session_variables_len);
+ shm_toc_insert(pcxt->toc, PARALLEL_KEY_SESSION_VARIABLES, session_variables_space);
+ SerializeSessionVariables(estate, &session_variables_space);
+
/* Allocate space for each worker's BufferUsage; no need to initialize. */
bufusage_space = shm_toc_allocate(pcxt->toc,
mul_size(sizeof(BufferUsage), pcxt->nworkers));
@@ -1413,6 +1433,7 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
SharedJitInstrumentation *jit_instrumentation;
int instrument_options = 0;
void *area_space;
+ char *sessionvariable_space;
dsa_area *area;
ParallelWorkerContext pwcxt;
@@ -1438,6 +1459,14 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
area_space = shm_toc_lookup(toc, PARALLEL_KEY_DSA, false);
area = dsa_attach_in_place(area_space, seg);
+ /* Reconstruct session variables. */
+ sessionvariable_space = shm_toc_lookup(toc,
+ PARALLEL_KEY_SESSION_VARIABLES,
+ false);
+ queryDesc->session_variables =
+ RestoreSessionVariables(&sessionvariable_space,
+ &queryDesc->num_session_variables);
+
/* Start up the executor */
queryDesc->plannedstmt->jitFlags = fpes->jit_flags;
ExecutorStart(queryDesc, fpes->eflags);
@@ -1505,3 +1534,117 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
FreeQueryDesc(queryDesc);
receiver->rDestroy(receiver);
}
+
+/*
+ * Estimate the amount of space required to serialize a session variable.
+ */
+static Size
+EstimateSessionVariables(EState *estate)
+{
+ int i;
+ Size sz = sizeof(int);
+
+ if (estate->es_session_variables == NULL)
+ return sz;
+
+ for (i = 0; i < estate->es_num_session_variables; i++)
+ {
+ SessionVariableValue *svarval;
+ Oid typeOid;
+ int16 typLen;
+ bool typByVal;
+
+ svarval = &estate->es_session_variables[i];
+
+ typeOid = svarval->typid;
+
+ sz = add_size(sz, sizeof(Oid)); /* space for type OID */
+
+ /* space for datum/isnull */
+ Assert(OidIsValid(typeOid));
+ get_typlenbyval(typeOid, &typLen, &typByVal);
+
+ sz = add_size(sz,
+ datumEstimateSpace(svarval->value, svarval->isnull, typByVal, typLen));
+ }
+
+ return sz;
+}
+
+/*
+ * Serialize a session variables buffer into caller-provided storage.
+ *
+ * We write the number of parameters first, as a 4-byte integer, and then
+ * write details for each parameter in turn. The details for each parameter
+ * consist of a 4-byte type OID, and then the datum as serialized by
+ * datumSerialize(). The caller is responsible for ensuring that there is
+ * enough storage to store the number of bytes that will be written; use
+ * EstimateSessionVariables to find out how many will be needed.
+ * *start_address is updated to point to the byte immediately following those
+ * written.
+ *
+ * RestoreSessionVariables can be used to recreate a session variable buffer
+ * based on the serialized representation;
+ */
+static void
+SerializeSessionVariables(EState *estate, char **start_address)
+{
+ int nparams;
+ int i;
+
+ /* Write number of parameters. */
+ nparams = estate->es_num_session_variables;
+ memcpy(*start_address, &nparams, sizeof(int));
+ *start_address += sizeof(int);
+
+ /* Write each parameter in turn. */
+ for (i = 0; i < nparams; i++)
+ {
+ SessionVariableValue *svarval;
+ Oid typeOid;
+ int16 typLen;
+ bool typByVal;
+
+ svarval = &estate->es_session_variables[i];
+ typeOid = svarval->typid;
+
+ /* Write type OID. */
+ memcpy(*start_address, &typeOid, sizeof(Oid));
+ *start_address += sizeof(Oid);
+
+ Assert(OidIsValid(typeOid));
+ get_typlenbyval(typeOid, &typLen, &typByVal);
+
+ datumSerialize(svarval->value, svarval->isnull, typByVal, typLen,
+ start_address);
+ }
+}
+
+static SessionVariableValue *
+RestoreSessionVariables(char **start_address, int *num_session_variables)
+{
+ SessionVariableValue *session_variables;
+ int i;
+ int nparams;
+
+ memcpy(&nparams, *start_address, sizeof(int));
+ *start_address += sizeof(int);
+
+ *num_session_variables = nparams;
+ session_variables = (SessionVariableValue *)
+ palloc(nparams * sizeof(SessionVariableValue));
+
+ for (i = 0; i < nparams; i++)
+ {
+ SessionVariableValue *svarval = &session_variables[i];
+
+ /* Read type OID. */
+ memcpy(&svarval->typid, *start_address, sizeof(Oid));
+ *start_address += sizeof(Oid);
+
+ /* Read datum/isnull. */
+ svarval->value = datumRestore(start_address, &svarval->isnull);
+ }
+
+ return session_variables;
+}
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index f60828f862e..175390c6c28 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -923,25 +923,19 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
/*
* We can't pass Params to workers at the moment either, so they are also
- * parallel-restricted, unless they are PARAM_EXTERN Params or are
- * PARAM_EXEC Params listed in safe_param_ids, meaning they could be
- * either generated within workers or can be computed by the leader and
- * then their value can be passed to workers.
+ * parallel-restricted, unless they are PARAM_EXTERN or PARAM_VARIABLE
+ * Params or are PARAM_EXEC Params listed in safe_param_ids, meaning they
+ * could be either generated within workers or can be computed by the
+ * leader and then their value can be passed to workers.
*/
else if (IsA(node, Param))
{
Param *param = (Param *) node;
- if (param->paramkind == PARAM_EXTERN)
+ if (param->paramkind == PARAM_EXTERN ||
+ param->paramkind == PARAM_VARIABLE)
return false;
- /* we don't support passing session variables to workers */
- if (param->paramkind == PARAM_VARIABLE)
- {
- if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
- return true;
- }
-
if (param->paramkind != PARAM_EXEC ||
!list_member_int(context->safe_param_ids, param->paramid))
{
diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c
index 6f22496305a..6f9bd7c8b05 100644
--- a/src/backend/tcop/pquery.c
+++ b/src/backend/tcop/pquery.c
@@ -86,6 +86,9 @@ CreateQueryDesc(PlannedStmt *plannedstmt,
qd->queryEnv = queryEnv;
qd->instrument_options = instrument_options; /* instrumentation wanted? */
+ qd->num_session_variables = 0;
+ qd->session_variables = NULL;
+
/* null these fields until set by ExecutorStart */
qd->tupDesc = NULL;
qd->estate = NULL;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index 4492bee6d69..f66b6c0b864 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -29,6 +29,7 @@ extern void AtEOSubXact_SessionVariables(bool isCommit, SubTransactionId mySubid
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
+extern Datum GetSessionVariableWithTypeid(Oid varid, bool *isNull, Oid *typid);
extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
QueryEnvironment *queryEnv, QueryCompletion *qc);
diff --git a/src/include/executor/execdesc.h b/src/include/executor/execdesc.h
index 86db3dc8d0d..4e0fa3ea40f 100644
--- a/src/include/executor/execdesc.h
+++ b/src/include/executor/execdesc.h
@@ -51,6 +51,10 @@ typedef struct QueryDesc
/* This field is set by ExecutePlan */
bool already_executed; /* true if previously executed */
+ /* reference to session variables buffer */
+ int num_session_variables;
+ SessionVariableValue *session_variables;
+
/* This is always set NULL by the core system, but plugins can change it */
struct Instrumentation *totaltime; /* total time spent in ExecutorRun */
} QueryDesc;
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 91051681d3b..c143b6419ed 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -641,6 +641,7 @@ typedef struct AsyncRequest
*/
typedef struct SessionVariableValue
{
+ Oid typid;
bool isnull;
Datum value;
} SessionVariableValue;
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 0ed2d5fbb01..d0658116683 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1284,12 +1284,14 @@ SELECT count(*) FROM svar_test WHERE a%10 = zero;
-- parallel execution is not supported yet
EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
- QUERY PLAN
------------------------------------
+ QUERY PLAN
+--------------------------------------------
Aggregate
- -> Seq Scan on svar_test
- Filter: ((a % 10) = zero)
-(3 rows)
+ -> Gather
+ Workers Planned: 2
+ -> Parallel Seq Scan on svar_test
+ Filter: ((a % 10) = zero)
+(5 rows)
LET zero = (SELECT count(*) FROM svar_test);
-- result should be 1000
--
2.48.1
[text/x-patch] v20250216-0013-Implementation-of-DEFAULT-clause-default-expressions.patch (32.1K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/17-v20250216-0013-Implementation-of-DEFAULT-clause-default-expressions.patch)
download | inline diff:
From 7ea6787f931f80772315b7da5e66605a9e40938b Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:03:53 +0100
Subject: [PATCH 13/21] Implementation of DEFAULT clause - default expressions
for session variables
When the evaluation of default expression fails, we remove related entry from sessionvars
hash table. Then sessionvars can contain only sucessfully initialized values. Then we don't
need special flag for badly initialized session variables.
---
doc/src/sgml/catalogs.sgml | 8 ++
doc/src/sgml/ddl.sgml | 16 ++--
doc/src/sgml/ref/create_variable.sgml | 21 +++--
doc/src/sgml/ref/discard.sgml | 3 +-
src/backend/catalog/pg_variable.c | 27 ++++++
src/backend/commands/session_variable.c | 87 ++++++++++++++++++-
src/backend/parser/gram.y | 15 +++-
src/backend/parser/parse_agg.c | 2 +
src/backend/parser/parse_expr.c | 4 +
src/backend/parser/parse_func.c | 1 +
src/bin/pg_dump/pg_dump.c | 14 +++
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_dump/t/002_pg_dump.pl | 36 ++++++++
src/bin/psql/describe.c | 4 +-
src/include/catalog/pg_variable.h | 3 +
src/include/nodes/parsenodes.h | 1 +
src/include/parser/parse_node.h | 1 +
src/test/regress/expected/psql.out | 36 ++++----
.../regress/expected/session_variables.out | 63 ++++++++++++++
src/test/regress/sql/session_variables.sql | 48 ++++++++++
20 files changed, 350 insertions(+), 41 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 687d1c8733a..27bdaf62668 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9899,6 +9899,14 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vardefexpr</structfield> <type>pg_node_tree</type>
+ </para>
+ <para>
+ The internal representation of the variable default value
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 3e2cb3c46eb..4c6988540e8 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5407,14 +5407,14 @@ SELECT current_user_id;
<para>
The value of a session variable is local to the current session. Retrieving
- a variable's value returns a <literal>NULL</literal>, unless its value has
- been set to something else in the current session using the
- <command>LET</command> command. Session variables are not transactional:
- any changes made to the value of a session variable in a transaction won't
- be undone if the transaction is rolled back (just like variables in
- procedural languages). Session variables themselves can be persistent
- or temporary, but their values are neither persistent nor shared (like the
- content of temporary tables).
+ a variable's value returns a <literal>NULL</literal> or a default value,
+ unless its value has been set to something else in the current session
+ using the <command>LET</command> command. Session variables are not
+ transactional: any changes made to the value of a session variable in
+ a transaction won't be undone if the transaction is rolled back (just like
+ variables in procedural languages). Session variables themselves can be
+ persistent or temporary, but their values are neither persistent nor shared
+ (like the content of temporary tables).
</para>
<para>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index c89a65fb55f..e4d8851ccb8 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -27,7 +27,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
- [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
+ [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -41,10 +41,10 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
<para>
The value of a session variable is local to the current session. Retrieving
- a session variable's value returns NULL, unless its value is set to
- something else in the current session with a <command>LET</command> command.
- The content of a session variable is not transactional. This is the same as
- regular variables in procedural languages.
+ a session variable's value returns NULL or a default value, unless its value
+ is set to something else in the current session with a <command>LET</command>
+ command. The content of a session variable is not transactional. This is the
+ same as regular variables in procedural languages.
</para>
<para>
@@ -105,6 +105,17 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-default">
+ <term><literal>DEFAULT <replaceable>default_expr</replaceable></literal></term>
+ <listitem>
+ <para>
+ The <literal>DEFAULT</literal> clause can be used to assign a default
+ value to a session variable. This expression is evaluated when the session
+ variable is first accessed for reading and had not yet been assigned a value.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createvariable-on-commit-drop">
<term><literal>ON COMMIT DROP</literal></term>
<listitem>
diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
index 61b967f9c9b..6b0cb95034f 100644
--- a/doc/src/sgml/ref/discard.sgml
+++ b/doc/src/sgml/ref/discard.sgml
@@ -71,7 +71,8 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES }
<listitem>
<para>
Resets the value of all session variables. If a variable
- is later reused, it is re-initialized to <literal>NULL</literal>.
+ is later reused, it is re-initialized to either
+ <literal>NULL</literal> or its default value.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 00c90ea6fd8..8fba4cc493b 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -24,6 +24,9 @@
#include "catalog/pg_variable.h"
#include "commands/session_variable.h"
#include "miscadmin.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_collate.h"
+#include "parser/parse_expr.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
@@ -37,6 +40,7 @@ static ObjectAddress create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ Node *varDefexpr,
VariableXactEndAction varXactEndAction);
@@ -51,6 +55,7 @@ create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ Node *varDefexpr,
VariableXactEndAction varXactEndAction)
{
Acl *varacl;
@@ -114,6 +119,11 @@ create_variable(const char *varName,
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
+ if (varDefexpr)
+ values[Anum_pg_variable_vardefexpr - 1] = CStringGetTextDatum(nodeToString(varDefexpr));
+ else
+ nulls[Anum_pg_variable_vardefexpr - 1] = true;
+
varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
varNamespace);
if (varacl != NULL)
@@ -150,6 +160,11 @@ create_variable(const char *varName,
record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
free_object_addresses(addrs);
+ /* dependency on default expr */
+ if (varDefexpr)
+ recordDependencyOnExpr(&myself, (Node *) varDefexpr,
+ NIL, DEPENDENCY_NORMAL);
+
/* dependency on owner */
recordDependencyOnOwner(VariableRelationId, varid, varOwner);
@@ -185,6 +200,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
Oid collation;
Oid typcollation;
ObjectAddress variable;
+ Node *cooked_default = NULL;
/* check consistency of arguments */
if (stmt->XactEndAction == VARIABLE_XACTEND_DROP
@@ -226,6 +242,16 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
format_type_be(typid)),
parser_errposition(pstate, stmt->collClause->location)));
+ if (stmt->defexpr)
+ {
+ cooked_default = transformExpr(pstate, stmt->defexpr,
+ EXPR_KIND_VARIABLE_DEFAULT);
+
+ cooked_default = coerce_to_specific_type(pstate,
+ cooked_default, typid, "DEFAULT");
+ assign_expr_collations(pstate, cooked_default);
+ }
+
variable = create_variable(stmt->variable->relname,
namespaceid,
typid,
@@ -233,6 +259,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
varowner,
collation,
stmt->if_not_exists,
+ cooked_default,
stmt->XactEndAction);
elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 035e5da08f2..40275abfa7e 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -22,6 +22,7 @@
#include "executor/svariableReceiver.h"
#include "funcapi.h"
#include "miscadmin.h"
+#include "optimizer/optimizer.h"
#include "rewrite/rewriteHandler.h"
#include "storage/lmgr.h"
#include "storage/proc.h"
@@ -510,11 +511,68 @@ AtEOSubXact_SessionVariables(bool isCommit,
}
}
+/*
+ * evaluate an expression
+ */
+static void
+eval_assign_defexpr(SVariable svar, HeapTuple tup)
+{
+ Datum defexpr_value;
+ bool isnull;
+
+ Assert(svar);
+ Assert(svar->is_valid);
+ Assert(HeapTupleIsValid(tup));
+
+ defexpr_value = SysCacheGetAttr(VARIABLEOID,
+ tup,
+ Anum_pg_variable_vardefexpr,
+ &isnull);
+
+ if (!isnull)
+ {
+ EState *estate;
+ ExprState *defexprs;
+ Expr *defexpr;
+ char *defexpr_str;
+ Datum value;
+ MemoryContext oldcxt;
+
+ estate = CreateExecutorState();
+
+ defexpr_str = TextDatumGetCString(defexpr_value);
+ defexpr = (Expr *) stringToNode(defexpr_str);
+
+ oldcxt = MemoryContextSwitchTo(estate->es_query_cxt);
+
+ defexpr = expression_planner((Expr *) defexpr);
+ defexprs = ExecInitExpr(defexpr, NULL);
+
+ value = ExecEvalExprSwitchContext(defexprs,
+ GetPerTupleExprContext(estate),
+ &isnull);
+
+ MemoryContextSwitchTo(oldcxt);
+
+ if (!isnull)
+ {
+ oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
+
+ svar->value = datumCopy(value, svar->typbyval, svar->typlen);
+ svar->isnull = false;
+
+ MemoryContextSwitchTo(oldcxt);
+ }
+
+ FreeExecutorState(estate);
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
static void
-setup_session_variable(SVariable svar, Oid varid)
+setup_session_variable(SVariable svar, Oid varid, bool is_write)
{
HeapTuple tup;
Form_pg_variable varform;
@@ -564,6 +622,9 @@ setup_session_variable(SVariable svar, Oid varid)
svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
ObjectIdGetDatum(varid));
+ if (!is_write)
+ eval_assign_defexpr(svar, tup);
+
ReleaseSysCache(tup);
}
@@ -593,7 +654,7 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
*/
if (!svar->is_valid)
{
- setup_session_variable(&locsvar, svar->varid);
+ setup_session_variable(&locsvar, svar->varid, false);
_svar = &locsvar;
}
else
@@ -726,7 +787,25 @@ get_session_variable(Oid varid)
*/
if (!svar->is_valid)
{
- setup_session_variable(svar, varid);
+ /* in this case we want to use defexp if it is defined */
+ PG_TRY();
+ {
+ /*
+ * In this case, the setup can execute default expression. When
+ * the execution of default expression fails, then we need to
+ * remove entry from session vars.
+ */
+ setup_session_variable(svar, varid, false);
+ }
+ PG_CATCH();
+ {
+ /* this entry cannot be valid, remove from sessionvars */
+ hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
+
+ /* propagate the error */
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)",
get_namespace_name(get_session_variable_namespace(varid)),
@@ -790,7 +869,7 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
if (!found)
{
- setup_session_variable(svar, varid);
+ setup_session_variable(svar, varid, true);
elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)",
get_namespace_name(get_session_variable_namespace(svar->varid)),
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 52e11c8d770..1d10eb7c52c 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -645,6 +645,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <partboundspec> PartitionBoundSpec
%type <list> hash_partbound
%type <defelt> hash_partbound_elem
+%type <node> OptSessionVarDefExpr
%type <node> json_format_clause
json_format_clause_opt
@@ -5264,30 +5265,36 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause XactEndActionOption
+ CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
$4->relpersistence = $2;
n->variable = $4;
n->typeName = $6;
n->collClause = (CollateClause *) $7;
- n->XactEndAction = $8;
+ n->defexpr = $8;
+ n->XactEndAction = $9;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause XactEndActionOption
+ | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
$7->relpersistence = $2;
n->variable = $7;
n->typeName = $9;
n->collClause = (CollateClause *) $10;
- n->XactEndAction = $11;
+ n->defexpr = $11;
+ n->XactEndAction = $12;
n->if_not_exists = true;
$$ = (Node *) n;
}
;
+OptSessionVarDefExpr: DEFAULT b_expr { $$ = $2; }
+ | /* EMPTY */ { $$ = NULL; }
+ ;
+
/*
* Temporary session variables can be dropped on successful
* transaction end like tables.
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 4737b04d171..54b765c8eb5 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -488,6 +488,7 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
if (isAgg)
err = _("aggregate functions are not allowed in DEFAULT expressions");
@@ -937,6 +938,7 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
err = _("window functions are not allowed in DEFAULT expressions");
break;
case EXPR_KIND_INDEX_EXPRESSION:
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index dd03b1f14db..158a67be523 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -588,6 +588,7 @@ expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
case EXPR_KIND_JOIN_USING:
case EXPR_KIND_CYCLE_MARK:
case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_VARIABLE_DEFAULT:
result = false;
break;
}
@@ -673,6 +674,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
case EXPR_KIND_CYCLE_MARK:
case EXPR_KIND_ASSIGN_TARGET:
case EXPR_KIND_LET_TARGET:
+ case EXPR_KIND_VARIABLE_DEFAULT:
/* okay */
break;
@@ -2146,6 +2148,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
err = _("cannot use subquery in DEFAULT expression");
break;
case EXPR_KIND_INDEX_EXPRESSION:
@@ -3508,6 +3511,7 @@ ParseExprKindName(ParseExprKind exprKind)
return "CHECK";
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
return "DEFAULT";
case EXPR_KIND_INDEX_EXPRESSION:
return "index expression";
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index dc25f6dcd0e..d9f15c2618f 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2620,6 +2620,7 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location)
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
err = _("set-returning functions are not allowed in DEFAULT expressions");
break;
case EXPR_KIND_INDEX_EXPRESSION:
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 83fd38cae34..b777ef967b6 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5440,6 +5440,7 @@ getVariables(Archive *fout)
int i_varnamespace;
int i_vartype;
int i_vartypname;
+ int i_vardefexpr;
int i_varxactendaction;
int i_varowner;
int i_varcollation;
@@ -5463,6 +5464,7 @@ getVariables(Archive *fout)
" THEN v.varcollation\n"
" ELSE 0\n"
" END AS varcollation,\n"
+ " pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n"
" v.varowner, v.varacl,\n"
" acldefault('V', v.varowner) AS acldefault\n"
"FROM pg_catalog.pg_variable v\n"
@@ -5479,6 +5481,7 @@ getVariables(Archive *fout)
i_varnamespace = PQfnumber(res, "varnamespace");
i_vartype = PQfnumber(res, "vartype");
i_vartypname = PQfnumber(res, "vartypname");
+ i_vardefexpr = PQfnumber(res, "vardefexpr");
i_varxactendaction = PQfnumber(res, "varxactendaction");
i_varcollation = PQfnumber(res, "varcollation");
@@ -5514,6 +5517,11 @@ getVariables(Archive *fout)
varinfo[i].dacl.initprivs = NULL;
varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner));
+ if (PQgetisnull(res, i, i_vardefexpr))
+ varinfo[i].vardefexpr = NULL;
+ else
+ varinfo[i].vardefexpr = pg_strdup(PQgetvalue(res, i, i_vardefexpr));
+
/* do not try to dump ACL if no ACL exists */
if (!PQgetisnull(res, i, i_varacl))
varinfo[i].dobj.components |= DUMP_COMPONENT_ACL;
@@ -5546,6 +5554,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
PQExpBuffer query;
char *qualvarname;
const char *vartypname;
+ const char *vardefexpr;
const char *varxactendaction;
Oid varcollation;
@@ -5558,6 +5567,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
vartypname = varinfo->vartypname;
+ vardefexpr = varinfo->vardefexpr;
varxactendaction = varinfo->varxactendaction;
varcollation = varinfo->varcollation;
@@ -5577,6 +5587,10 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
fmtQualifiedDumpable(coll));
}
+ if (vardefexpr)
+ appendPQExpBuffer(query, " DEFAULT %s",
+ vardefexpr);
+
if (strcmp(varxactendaction, "r") == 0)
appendPQExpBuffer(query, " ON TRANSACTION END RESET");
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index e815b411f0f..ef1ba042132 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -718,6 +718,7 @@ typedef struct _VariableInfo
DumpableAcl dacl;
Oid vartype;
char *vartypname;
+ char *vardefexpr;
char *varxactendaction;
Oid varcollation;
const char *rolname; /* name of owner, or empty string */
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 4a70f4cd699..fb25f80a852 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4072,6 +4072,42 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable DEFAULT' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable3 AS integer DEFAULT 10;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable3 AS integer DEFAULT 10;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
+ 'CREATE VARIABLE test_variable DEFAULT ON TRANSACTION END RESET' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable4 AS integer DEFAULT 10 ON TRANSACTION END RESET',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable4 AS integer DEFAULT 10 ON TRANSACTION END RESET;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index d3b1442eb2f..b5e5d073f9c 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5352,6 +5352,7 @@ listVariables(const char *pattern, bool verbose)
" (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
" WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
+ " pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
" WHEN 'r' THEN 'ON TRANSACTION END RESET'\n"
@@ -5361,6 +5362,7 @@ listVariables(const char *pattern, bool verbose)
gettext_noop("Type"),
gettext_noop("Collation"),
gettext_noop("Owner"),
+ gettext_noop("Default"),
gettext_noop("Transactional end action"));
if (verbose)
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 008f2ee7c17..09dd44a44e1 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -68,6 +68,9 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* access permissions */
aclitem varacl[1] BKI_DEFAULT(_null_);
+ /* list of expression trees for variable default (NULL if none) */
+ pg_node_tree vardefexpr BKI_DEFAULT(_null_);
+
#endif
} FormData_pg_variable;
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 04d4a853a3c..d1d2ac91fb5 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3535,6 +3535,7 @@ typedef struct CreateSessionVarStmt
TypeName *typeName; /* the type of variable */
CollateClause *collClause;
bool if_not_exists; /* do nothing if it already exists */
+ Node *defexpr; /* default expression */
char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 0b7b69a4159..6b55cc8308b 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -84,6 +84,7 @@ typedef enum ParseExprKind
EXPR_KIND_CYCLE_MARK, /* cycle mark value */
EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */
EXPR_KIND_LET_TARGET, /* LET target */
+ EXPR_KIND_VARIABLE_DEFAULT, /* default value for session variable */
} ParseExprKind;
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 3ddbcc7cc2a..999fc88d1e1 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6020,20 +6020,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+--------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+---------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+--------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+---------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6501,9 +6501,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action
---------+------+------+-----------+-------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action
+--------+------+------+-----------+-------+---------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6676,9 +6676,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action
---------+------+------+-----------+-------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action
+--------+------+------+-----------+-------+---------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6815,9 +6815,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action
---------+------+------+-----------+-------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action
+--------+------+------+-----------+-------+---------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7b3ed43618f..5640875dc59 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2299,3 +2299,66 @@ SELECT var1 IS NULL;
(1 row)
DROP VARIABLE var1;
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE NOTICE 'vartest_fx executed';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+CREATE VARIABLE var1 AS int DEFAULT vartest_fx();
+-- vartest_fx should be protected by dep, should fail
+DROP FUNCTION vartest_fx();
+ERROR: cannot drop function vartest_fx() because other objects depend on it
+DETAIL: session variable var1 depends on function vartest_fx()
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+SELECT var1;
+NOTICE: vartest_fx executed
+ var1
+------
+ 0
+(1 row)
+
+-- the defexpr should be evaluated only once
+SELECT var1;
+ var1
+------
+ 0
+(1 row)
+
+DISCARD VARIABLES;
+-- in this case, the defexpr should not be evaluated
+LET var1 = 100;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DISCARD VARIABLES;
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE EXCEPTION 'vartest_fx is executing';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+-- should to fail, but not to crash
+SELECT var1;
+ERROR: vartest_fx is executing
+CONTEXT: PL/pgSQL function vartest_fx() line 3 at RAISE
+-- again
+SELECT var1;
+ERROR: vartest_fx is executing
+CONTEXT: PL/pgSQL function vartest_fx() line 3 at RAISE
+-- but we can write
+LET var1 = 100;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index d6e7c21bf16..2c7388639d9 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1565,3 +1565,51 @@ ROLLBACK;
SELECT var1 IS NULL;
DROP VARIABLE var1;
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE NOTICE 'vartest_fx executed';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE VARIABLE var1 AS int DEFAULT vartest_fx();
+
+-- vartest_fx should be protected by dep, should fail
+DROP FUNCTION vartest_fx();
+
+-- should be ok
+SELECT var1;
+
+-- the defexpr should be evaluated only once
+SELECT var1;
+
+DISCARD VARIABLES;
+
+-- in this case, the defexpr should not be evaluated
+LET var1 = 100;
+SELECT var1;
+
+DISCARD VARIABLES;
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE EXCEPTION 'vartest_fx is executing';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+
+-- should to fail, but not to crash
+SELECT var1;
+
+-- again
+SELECT var1;
+
+-- but we can write
+LET var1 = 100;
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
--
2.48.1
[text/x-patch] v20250216-0019-this-patch-changes-error-message-column-doesn-t-exis.patch (29.2K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/18-v20250216-0019-this-patch-changes-error-message-column-doesn-t-exis.patch)
download | inline diff:
From 1603579af1ae505e7eafa399adb9a259f57fbcd3 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:10:39 +0100
Subject: [PATCH 19/21] this patch changes error message "column doesn't exist"
to message "column or variable doesn't exist"
The error message will be more correct. Today, missing PL/pgSQL variable can be reported. The change has
impact on lot of regress tests not directly related to session variables, and then it is distributed as separate patch
---
src/backend/parser/parse_expr.c | 2 +-
src/backend/parser/parse_relation.c | 24 +++++++++++---
src/backend/parser/parse_target.c | 8 +++--
src/include/parser/parse_expr.h | 2 ++
src/pl/plpgsql/src/expected/plpgsql_array.out | 2 +-
.../plpgsql/src/expected/plpgsql_record.out | 4 +--
.../src/expected/plpgsql_session_variable.out | 2 +-
src/pl/tcl/expected/pltcl_queries.out | 12 +++----
.../isolation/expected/session-variable.out | 4 +--
src/test/regress/expected/alter_table.out | 32 +++++++++----------
src/test/regress/expected/copy2.out | 2 +-
src/test/regress/expected/errors.out | 8 ++---
src/test/regress/expected/join.out | 12 +++----
src/test/regress/expected/namespace.out | 2 +-
src/test/regress/expected/numerology.out | 2 +-
src/test/regress/expected/plpgsql.out | 12 +++----
src/test/regress/expected/psql.out | 2 +-
src/test/regress/expected/rules.out | 2 +-
.../regress/expected/session_variables.out | 6 ++--
src/test/regress/expected/transactions.out | 4 +--
src/test/regress/expected/union.out | 2 +-
21 files changed, 83 insertions(+), 63 deletions(-)
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 158a67be523..7c4a584f0f4 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -526,7 +526,7 @@ transformIndirection(ParseState *pstate, A_Indirection *ind)
* printed. When we are in an expression where session variables cannot be
* used, we raise the first form of error message.
*/
-static bool
+bool
expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
{
bool result = false;
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index bec6947ea2d..7bc75319e50 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -27,6 +27,7 @@
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "parser/parse_enr.h"
+#include "parser/parse_expr.h"
#include "parser/parse_relation.h"
#include "parser/parse_type.h"
#include "parser/parsetree.h"
@@ -3761,6 +3762,19 @@ errorMissingRTE(ParseState *pstate, RangeVar *relation)
parser_errposition(pstate, relation->location)));
}
+/*
+ * set message "column does not exist" or "column or variable does not exist"
+ * in dependency if expression context allows session variables.
+ */
+static int
+column_or_variable_does_not_exists(ParseState *pstate, const char *colname)
+{
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind))
+ return errmsg("column or variable \"%s\" does not exist", colname);
+ else
+ return errmsg("column \"%s\" does not exist", colname);
+}
+
/*
* Generate a suitable error about a missing column.
*
@@ -3795,7 +3809,7 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errdetail("There are columns named \"%s\", but they are in tables that cannot be referenced from this part of the query.",
colname),
!relname ? errhint("Try using a table-qualified name.") : 0,
@@ -3805,7 +3819,7 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errdetail("There is a column named \"%s\" in table \"%s\", but it cannot be referenced from this part of the query.",
colname, state->rexact1->eref->aliasname),
rte_visible_if_lateral(pstate, state->rexact1) ?
@@ -3823,14 +3837,14 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
parser_errposition(pstate, location)));
/* Handle case where we have a single alternative spelling to offer */
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errhint("Perhaps you meant to reference the column \"%s.%s\".",
state->rfirst->eref->aliasname,
strVal(list_nth(state->rfirst->eref->colnames,
@@ -3844,7 +3858,7 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errhint("Perhaps you meant to reference the column \"%s.%s\" or the column \"%s.%s\".",
state->rfirst->eref->aliasname,
strVal(list_nth(state->rfirst->eref->colnames,
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index cf01bff65a9..2a527887a8d 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -779,7 +779,9 @@ transformAssignmentIndirection(ParseState *pstate,
if (!typrelid)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
- errmsg("cannot assign to field \"%s\" of column \"%s\" because its type %s is not a composite type",
+ errmsg(expr_kind_allows_session_variables(pstate->p_expr_kind) ?
+ "cannot assign to field \"%s\" of column or variable \"%s\" because its type %s is not a composite type" :
+ "cannot assign to field \"%s\" of column \"%s\" because its type %s is not a composite type",
strVal(n), targetName,
format_type_be(targetTypeId)),
parser_errposition(pstate, location)));
@@ -788,7 +790,9 @@ transformAssignmentIndirection(ParseState *pstate,
if (attnum == InvalidAttrNumber)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
- errmsg("cannot assign to field \"%s\" of column \"%s\" because there is no such column in data type %s",
+ errmsg(expr_kind_allows_session_variables(pstate->p_expr_kind) ?
+ "cannot assign to field \"%s\" of column or variable \"%s\" because there is no such column in data type %s" :
+ "cannot assign to field \"%s\" of column \"%s\" because there is no such column in data type %s",
strVal(n), targetName,
format_type_be(targetTypeId)),
parser_errposition(pstate, location)));
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index 5bde43758d1..71ec213f884 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -24,4 +24,6 @@ extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKin
extern const char *ParseExprKindName(ParseExprKind exprKind);
+extern bool expr_kind_allows_session_variables(ParseExprKind p_expr_kind);
+
#endif /* PARSE_EXPR_H */
diff --git a/src/pl/plpgsql/src/expected/plpgsql_array.out b/src/pl/plpgsql/src/expected/plpgsql_array.out
index 4c6b3ce998a..ad6692c3e52 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_array.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_array.out
@@ -41,7 +41,7 @@ NOTICE: a = {"(,11)"}, a[1].i = 11
-- perhaps this ought to work, but for now it doesn't:
do $$ declare a complex[];
begin a[1:2].i := array[11,12]; raise notice 'a = %', a; end$$;
-ERROR: cannot assign to field "i" of column "a" because its type complex[] is not a composite type
+ERROR: cannot assign to field "i" of column or variable "a" because its type complex[] is not a composite type
LINE 1: a[1:2].i := array[11,12]
^
QUERY: a[1:2].i := array[11,12]
diff --git a/src/pl/plpgsql/src/expected/plpgsql_record.out b/src/pl/plpgsql/src/expected/plpgsql_record.out
index 6974c8f4a44..3970ac721c9 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_record.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_record.out
@@ -135,7 +135,7 @@ ERROR: record "c" has no field "x"
CONTEXT: PL/pgSQL assignment "c.x.q1 = 1"
PL/pgSQL function inline_code_block line 1 at assignment
do $$ declare c nested_int8s; begin c.c2.x = 1; end $$;
-ERROR: cannot assign to field "x" of column "c" because there is no such column in data type two_int8s
+ERROR: cannot assign to field "x" of column or variable "c" because there is no such column in data type two_int8s
LINE 1: c.c2.x = 1
^
QUERY: c.c2.x = 1
@@ -157,7 +157,7 @@ ERROR: record "c" has no field "x"
CONTEXT: PL/pgSQL assignment "b.c.x.q1 = 1"
PL/pgSQL function inline_code_block line 1 at assignment
do $$ <<b>> declare c nested_int8s; begin b.c.c2.x = 1; end $$;
-ERROR: cannot assign to field "x" of column "b" because there is no such column in data type two_int8s
+ERROR: cannot assign to field "x" of column or variable "b" because there is no such column in data type two_int8s
LINE 1: b.c.c2.x = 1
^
QUERY: b.c.c2.x = 1
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index ecac64fcfb4..8bd2b398bdd 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -232,7 +232,7 @@ SET ROLE TO DEFAULT;
SET ROLE TO regress_var_exec_role;
-- should fail, but not crash
SELECT var_read_func();
-ERROR: column "plpgsql_sv_var1" does not exist
+ERROR: column or variable "plpgsql_sv_var1" does not exist
LINE 1: plpgsql_sv_var1
^
QUERY: plpgsql_sv_var1
diff --git a/src/pl/tcl/expected/pltcl_queries.out b/src/pl/tcl/expected/pltcl_queries.out
index 35cc6e62aad..497cd38189b 100644
--- a/src/pl/tcl/expected/pltcl_queries.out
+++ b/src/pl/tcl/expected/pltcl_queries.out
@@ -450,12 +450,12 @@ CONTEXT: while executing
"__PLTcl_proc_tcl_eval_text spi_prepare\ a\ \"b\ \{\""
in PL/Tcl function tcl_eval(text)
select tcl_error_handling_test($tcl$spi_prepare "select moo" []$tcl$);
- tcl_error_handling_test
---------------------------------------
- SQLSTATE: 42703 +
- condition: undefined_column +
- cursor_position: 8 +
- message: column "moo" does not exist+
+ tcl_error_handling_test
+--------------------------------------------------
+ SQLSTATE: 42703 +
+ condition: undefined_column +
+ cursor_position: 8 +
+ message: column or variable "moo" does not exist+
statement: select moo
(1 row)
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
index e9a254bcd12..d8848d555cd 100644
--- a/src/test/isolation/expected/session-variable.out
+++ b/src/test/isolation/expected/session-variable.out
@@ -10,7 +10,7 @@ test
step drop: DROP VARIABLE myvar;
step val: SELECT myvar;
-ERROR: column "myvar" does not exist
+ERROR: column or variable "myvar" does not exist
starting permutation: let val s1 drop val sr1
step let: LET myvar = 'test';
@@ -23,7 +23,7 @@ test
step s1: BEGIN;
step drop: DROP VARIABLE myvar;
step val: SELECT myvar;
-ERROR: column "myvar" does not exist
+ERROR: column or variable "myvar" does not exist
step sr1: ROLLBACK;
starting permutation: let val dbg drop create dbg val
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 362f38856d2..299dbdb5e43 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -1298,19 +1298,19 @@ select * from atacc1;
(1 row)
select * from atacc1 order by a;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select * from atacc1 order by a;
^
select * from atacc1 order by "........pg.dropped.1........";
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select * from atacc1 order by "........pg.dropped.1........"...
^
select * from atacc1 group by a;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select * from atacc1 group by a;
^
select * from atacc1 group by "........pg.dropped.1........";
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select * from atacc1 group by "........pg.dropped.1........"...
^
select atacc1.* from atacc1;
@@ -1320,7 +1320,7 @@ select atacc1.* from atacc1;
(1 row)
select a from atacc1;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select a from atacc1;
^
select atacc1.a from atacc1;
@@ -1334,15 +1334,15 @@ select b,c,d from atacc1;
(1 row)
select a,b,c,d from atacc1;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select a,b,c,d from atacc1;
^
select * from atacc1 where a = 1;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select * from atacc1 where a = 1;
^
select "........pg.dropped.1........" from atacc1;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select "........pg.dropped.1........" from atacc1;
^
select atacc1."........pg.dropped.1........" from atacc1;
@@ -1350,11 +1350,11 @@ ERROR: column atacc1.........pg.dropped.1........ does not exist
LINE 1: select atacc1."........pg.dropped.1........" from atacc1;
^
select "........pg.dropped.1........",b,c,d from atacc1;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select "........pg.dropped.1........",b,c,d from atacc1;
^
select * from atacc1 where "........pg.dropped.1........" = 1;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select * from atacc1 where "........pg.dropped.1........" = ...
^
-- UPDATEs
@@ -1363,7 +1363,7 @@ ERROR: column "a" of relation "atacc1" does not exist
LINE 1: update atacc1 set a = 3;
^
update atacc1 set b = 2 where a = 3;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: update atacc1 set b = 2 where a = 3;
^
update atacc1 set "........pg.dropped.1........" = 3;
@@ -1371,7 +1371,7 @@ ERROR: column "........pg.dropped.1........" of relation "atacc1" does not exis
LINE 1: update atacc1 set "........pg.dropped.1........" = 3;
^
update atacc1 set b = 2 where "........pg.dropped.1........" = 3;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: update atacc1 set b = 2 where "........pg.dropped.1........"...
^
-- INSERTs
@@ -1419,11 +1419,11 @@ LINE 1: insert into atacc1 ("........pg.dropped.1........",b,c,d) va...
^
-- DELETEs
delete from atacc1 where a = 3;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: delete from atacc1 where a = 3;
^
delete from atacc1 where "........pg.dropped.1........" = 3;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: delete from atacc1 where "........pg.dropped.1........" = 3;
^
delete from atacc1;
@@ -1716,7 +1716,7 @@ select f1 from c1;
alter table c1 drop column f1;
select f1 from c1;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1 from c1;
^
HINT: Perhaps you meant to reference the column "c1.f2".
@@ -1730,7 +1730,7 @@ ERROR: cannot drop inherited column "f1"
alter table p1 drop column f1;
-- c1.f1 is dropped now, since there is no local definition for it
select f1 from c1;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1 from c1;
^
HINT: Perhaps you meant to reference the column "c1.f2".
diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 64ea33aeae8..6874f5ae0d1 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -160,7 +160,7 @@ LINE 1: COPY x TO stdout WHERE a = 1;
COPY x from stdin WHERE a = 50004;
COPY x from stdin WHERE a > 60003;
COPY x from stdin WHERE f > 60003;
-ERROR: column "f" does not exist
+ERROR: column or variable "f" does not exist
LINE 1: COPY x from stdin WHERE f > 60003;
^
COPY x from stdin WHERE a = max(x.b);
diff --git a/src/test/regress/expected/errors.out b/src/test/regress/expected/errors.out
index 8c527474daf..e53ae451dfc 100644
--- a/src/test/regress/expected/errors.out
+++ b/src/test/regress/expected/errors.out
@@ -27,7 +27,7 @@ LINE 1: select * from nonesuch;
^
-- bad name in target list
select nonesuch from pg_database;
-ERROR: column "nonesuch" does not exist
+ERROR: column or variable "nonesuch" does not exist
LINE 1: select nonesuch from pg_database;
^
-- empty distinct list isn't OK
@@ -37,17 +37,17 @@ LINE 1: select distinct from pg_database;
^
-- bad attribute name on lhs of operator
select * from pg_database where nonesuch = pg_database.datname;
-ERROR: column "nonesuch" does not exist
+ERROR: column or variable "nonesuch" does not exist
LINE 1: select * from pg_database where nonesuch = pg_database.datna...
^
-- bad attribute name on rhs of operator
select * from pg_database where pg_database.datname = nonesuch;
-ERROR: column "nonesuch" does not exist
+ERROR: column or variable "nonesuch" does not exist
LINE 1: ...ect * from pg_database where pg_database.datname = nonesuch;
^
-- bad attribute name in select distinct on
select distinct on (foobar) * from pg_database;
-ERROR: column "foobar" does not exist
+ERROR: column or variable "foobar" does not exist
LINE 1: select distinct on (foobar) * from pg_database;
^
-- grouping with FOR UPDATE
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index 3ffc066b1f8..6daff885128 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -6394,13 +6394,13 @@ LINE 1: select t2.uunique1 from
HINT: Perhaps you meant to reference the column "t2.unique1".
select uunique1 from
tenk1 t1 join tenk2 t2 on t1.two = t2.two; -- error, suggest both at once
-ERROR: column "uunique1" does not exist
+ERROR: column or variable "uunique1" does not exist
LINE 1: select uunique1 from
^
HINT: Perhaps you meant to reference the column "t1.unique1" or the column "t2.unique1".
select ctid from
tenk1 t1 join tenk2 t2 on t1.two = t2.two; -- error, need qualification
-ERROR: column "ctid" does not exist
+ERROR: column or variable "ctid" does not exist
LINE 1: select ctid from
^
DETAIL: There are columns named "ctid", but they are in tables that cannot be referenced from this part of the query.
@@ -7497,7 +7497,7 @@ lateral (select * from int8_tbl t1,
-- test some error cases where LATERAL should have been used but wasn't
select f1,g from int4_tbl a, (select f1 as g) ss;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1,g from int4_tbl a, (select f1 as g) ss;
^
DETAIL: There is a column named "f1" in table "a", but it cannot be referenced from this part of the query.
@@ -7509,7 +7509,7 @@ LINE 1: select f1,g from int4_tbl a, (select a.f1 as g) ss;
DETAIL: There is an entry for table "a", but it cannot be referenced from this part of the query.
HINT: To reference that table, you must mark this subquery with LATERAL.
select f1,g from int4_tbl a cross join (select f1 as g) ss;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1,g from int4_tbl a cross join (select f1 as g) ss;
^
DETAIL: There is a column named "f1" in table "a", but it cannot be referenced from this part of the query.
@@ -7546,7 +7546,7 @@ LINE 1: select 1 from tenk1 a, lateral (select max(a.unique1) from i...
create temp table xx1 as select f1 as x1, -f1 as x2 from int4_tbl;
-- error, can't do this:
update xx1 set x2 = f1 from (select * from int4_tbl where f1 = x1) ss;
-ERROR: column "x1" does not exist
+ERROR: column or variable "x1" does not exist
LINE 1: ... set x2 = f1 from (select * from int4_tbl where f1 = x1) ss;
^
DETAIL: There is a column named "x1" in table "xx1", but it cannot be referenced from this part of the query.
@@ -7566,7 +7566,7 @@ update xx1 set x2 = f1 from xx1, lateral (select * from int4_tbl where f1 = x1)
ERROR: table name "xx1" specified more than once
-- also errors:
delete from xx1 using (select * from int4_tbl where f1 = x1) ss;
-ERROR: column "x1" does not exist
+ERROR: column or variable "x1" does not exist
LINE 1: ...te from xx1 using (select * from int4_tbl where f1 = x1) ss;
^
DETAIL: There is a column named "x1" in table "xx1", but it cannot be referenced from this part of the query.
diff --git a/src/test/regress/expected/namespace.out b/src/test/regress/expected/namespace.out
index dbbda72d395..d98793f92a7 100644
--- a/src/test/regress/expected/namespace.out
+++ b/src/test/regress/expected/namespace.out
@@ -23,7 +23,7 @@ BEGIN;
SET search_path to public, test_ns_schema_1;
CREATE SCHEMA test_ns_schema_2
CREATE VIEW abc_view AS SELECT c FROM abc;
-ERROR: column "c" does not exist
+ERROR: column or variable "c" does not exist
LINE 2: CREATE VIEW abc_view AS SELECT c FROM abc;
^
COMMIT;
diff --git a/src/test/regress/expected/numerology.out b/src/test/regress/expected/numerology.out
index 9e23166fed1..672012e1461 100644
--- a/src/test/regress/expected/numerology.out
+++ b/src/test/regress/expected/numerology.out
@@ -314,7 +314,7 @@ NOTICE: i = 1002
NOTICE: i = 1003
-- error cases
SELECT _100;
-ERROR: column "_100" does not exist
+ERROR: column or variable "_100" does not exist
LINE 1: SELECT _100;
^
SELECT 100_;
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index 0a6945581bd..5c599ba312e 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -2598,7 +2598,7 @@ end; $$ language plpgsql;
-- should fail: SQLSTATE and SQLERRM are only in defined EXCEPTION
-- blocks
select excpt_test1();
-ERROR: column "sqlstate" does not exist
+ERROR: column or variable "sqlstate" does not exist
LINE 1: sqlstate
^
QUERY: sqlstate
@@ -2613,7 +2613,7 @@ begin
end; $$ language plpgsql;
-- should fail
select excpt_test2();
-ERROR: column "sqlstate" does not exist
+ERROR: column or variable "sqlstate" does not exist
LINE 1: sqlstate
^
QUERY: sqlstate
@@ -4675,7 +4675,7 @@ BEGIN
RAISE NOTICE '%, %', r.roomno, r.comment;
END LOOP;
END$$;
-ERROR: column "foo" does not exist
+ERROR: column or variable "foo" does not exist
LINE 1: SELECT rtrim(roomno) AS roomno, foo FROM Room ORDER BY roomn...
^
QUERY: SELECT rtrim(roomno) AS roomno, foo FROM Room ORDER BY roomno
@@ -4717,7 +4717,7 @@ begin
raise notice 'x = %', x;
end;
$$;
-ERROR: column "x" does not exist
+ERROR: column or variable "x" does not exist
LINE 1: x + 1
^
QUERY: x + 1
@@ -4729,7 +4729,7 @@ begin
raise notice 'x = %, y = %', x, y;
end;
$$;
-ERROR: column "x" does not exist
+ERROR: column or variable "x" does not exist
LINE 1: x + 1
^
QUERY: x + 1
@@ -5769,7 +5769,7 @@ ALTER TABLE alter_table_under_transition_tables
DROP column name;
UPDATE alter_table_under_transition_tables
SET id = id;
-ERROR: column "name" does not exist
+ERROR: column or variable "name" does not exist
LINE 1: (SELECT string_agg(id || '=' || name, ',') FROM d)
^
QUERY: (SELECT string_agg(id || '=' || name, ',') FROM d)
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 78aca67e452..ec870172faa 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -214,7 +214,7 @@ select $1::int as col \bind 1 \g \bind 2 \g
-- errors
-- parse error
SELECT foo \bind \g
-ERROR: column "foo" does not exist
+ERROR: column or variable "foo" does not exist
LINE 1: SELECT foo
^
-- tcop error
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 5baba8d39ff..f1b5b73a86a 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1191,7 +1191,7 @@ drop rule rules_foorule on rules_foo;
-- this should fail because f1 is not exposed for unqualified reference:
create rule rules_foorule as on insert to rules_foo where f1 < 100
do instead insert into rules_foo2 values (f1);
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 2: do instead insert into rules_foo2 values (f1);
^
DETAIL: There are columns named "f1", but they are in tables that cannot be referenced from this part of the query.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 0d6c09ac42d..7b71bba90e9 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -811,7 +811,7 @@ ERROR: session variable "var1" doesn't exist
LINE 1: LET var1 = pi();
^
SELECT var1;
-ERROR: column "var1" does not exist
+ERROR: column or variable "var1" does not exist
LINE 1: SELECT var1;
^
-- should be ok
@@ -1030,7 +1030,7 @@ SELECT v1;
-- should fail, attribute doesn't exist
LET v1.x = 10;
-ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1
+ERROR: cannot assign to field "x" of column or variable "v1" because there is no such column in data type t1
LINE 1: LET v1.x = 10;
^
-- should fail, don't allow multi column query
@@ -1750,7 +1750,7 @@ BEGIN;
DROP VARIABLE var1;
-- should fail
SELECT var1;
-ERROR: column "var1" does not exist
+ERROR: column or variable "var1" does not exist
LINE 1: SELECT var1;
^
ROLLBACK;
diff --git a/src/test/regress/expected/transactions.out b/src/test/regress/expected/transactions.out
index 7f5757e89c4..b05b16d94bf 100644
--- a/src/test/regress/expected/transactions.out
+++ b/src/test/regress/expected/transactions.out
@@ -256,7 +256,7 @@ SELECT * FROM trans_barbaz; -- should have 1
BEGIN;
SAVEPOINT one;
SELECT trans_foo;
-ERROR: column "trans_foo" does not exist
+ERROR: column or variable "trans_foo" does not exist
LINE 1: SELECT trans_foo;
^
ROLLBACK TO SAVEPOINT one;
@@ -305,7 +305,7 @@ BEGIN;
SAVEPOINT one;
INSERT INTO savepoints VALUES (5);
SELECT trans_foo;
-ERROR: column "trans_foo" does not exist
+ERROR: column or variable "trans_foo" does not exist
LINE 1: SELECT trans_foo;
^
COMMIT;
diff --git a/src/test/regress/expected/union.out b/src/test/regress/expected/union.out
index caa8fe70a05..1d3447e84dd 100644
--- a/src/test/regress/expected/union.out
+++ b/src/test/regress/expected/union.out
@@ -939,7 +939,7 @@ ORDER BY q2,q1;
-- This should fail, because q2 isn't a name of an EXCEPT output column
SELECT q1 FROM int8_tbl EXCEPT SELECT q2 FROM int8_tbl ORDER BY q2 LIMIT 1;
-ERROR: column "q2" does not exist
+ERROR: column or variable "q2" does not exist
LINE 1: ... int8_tbl EXCEPT SELECT q2 FROM int8_tbl ORDER BY q2 LIMIT 1...
^
DETAIL: There is a column named "q2" in table "*SELECT* 2", but it cannot be referenced from this part of the query.
--
2.48.1
[text/x-patch] v20250216-0018-expression-with-session-variables-can-be-inlined.patch (4.2K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/19-v20250216-0018-expression-with-session-variables-can-be-inlined.patch)
download | inline diff:
From 42dfa5b8c3b8cebb18d34669b188d783bc5ebe03 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sat, 20 Jan 2024 20:35:38 +0100
Subject: [PATCH 18/21] expression with session variables can be inlined
There is not an reason why session variables should to block inlining.
(of SQL functions). I can imagine some use cases like wrapping, and
inlining significantly reduces an overhead of SQL functions.
---
src/backend/optimizer/util/clauses.c | 37 ++++++++++++++-----
.../regress/expected/session_variables.out | 7 ++--
2 files changed, 30 insertions(+), 14 deletions(-)
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 175390c6c28..0eb52fa2081 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -4744,8 +4744,7 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
querytree->limitOffset ||
querytree->limitCount ||
querytree->setOperations ||
- (list_length(querytree->targetList) != 1) ||
- querytree->hasSessionVariables)
+ (list_length(querytree->targetList) != 1))
goto fail;
/* If the function result is composite, resolve it */
@@ -4949,21 +4948,39 @@ substitute_actual_parameters_mutator(Node *node,
{
if (node == NULL)
return NULL;
+
+
+ /*
+ * SQL functions can contain two different kind of params. The nodes with
+ * paramkind PARAM_EXTERN are related to function's arguments (and should
+ * be replaced in this step), because this is how we apply the function's
+ * arguments for an expression.
+ *
+ * The nodes with paramkind PARAM_VARIABLE are related to usage of session
+ * variables. The values of session variables are not passed to expression
+ * by expression arguments, so it should not be replaced here by
+ * function's arguments.
+ */
if (IsA(node, Param))
{
Param *param = (Param *) node;
- if (param->paramkind != PARAM_EXTERN)
+ if (param->paramkind != PARAM_EXTERN &&
+ param->paramkind != PARAM_VARIABLE)
elog(ERROR, "unexpected paramkind: %d", (int) param->paramkind);
- if (param->paramid <= 0 || param->paramid > context->nargs)
- elog(ERROR, "invalid paramid: %d", param->paramid);
- /* Count usage of parameter */
- context->usecounts[param->paramid - 1]++;
+ if (param->paramkind == PARAM_EXTERN)
+ {
+ if (param->paramid <= 0 || param->paramid > context->nargs)
+ elog(ERROR, "invalid paramid: %d", param->paramid);
- /* Select the appropriate actual arg and replace the Param with it */
- /* We don't need to copy at this time (it'll get done later) */
- return list_nth(context->args, param->paramid - 1);
+ /* Count usage of parameter */
+ context->usecounts[param->paramid - 1]++;
+
+ /* Select the appropriate actual arg and replace the Param with it */
+ /* We don't need to copy at this time (it'll get done later) */
+ return list_nth(context->args, param->paramid - 1);
+ }
}
return expression_tree_mutator(node, substitute_actual_parameters_mutator, context);
}
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index c25d804f8c1..0d6c09ac42d 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -480,7 +480,6 @@ SELECT var1;
ERROR: permission denied for session variable var1
SELECT sqlfx(20);
ERROR: permission denied for session variable var1
-CONTEXT: SQL function "sqlfx" statement 1
SELECT plpgsqlfx(20);
ERROR: permission denied for session variable var1
CONTEXT: PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
@@ -587,10 +586,10 @@ SELECT sqlfx1(sqlfx2('Hello'));
-- inlining is blocked
EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
- QUERY PLAN
-------------------------------------------------------
+ QUERY PLAN
+-----------------------------------------------------------------------------
Result
- Output: sqlfx1(sqlfx2('Hello'::character varying))
+ Output: ((var1 || ', '::text) || ((var2 || ', '::text) || 'Hello'::text))
(2 rows)
DROP FUNCTION sqlfx1(varchar);
--
2.48.1
[text/x-patch] v20250216-0017-plpgsql-implementation-for-LET-statement.patch (16.8K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/20-v20250216-0017-plpgsql-implementation-for-LET-statement.patch)
download | inline diff:
From 845401b79679fbcdc6ba95c5fa4c0ceb5b609763 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sat, 20 Jan 2024 08:56:17 +0100
Subject: [PATCH 17/21] plpgsql implementation for LET statement
PLpgSQL allows to call expression executor directly (for simple expression).
This possibility strongly reduces overhead related to execution. Reimplementation
of LET statement (inside PLpgSQL) allows to use this possibility, and strongly
increase performance:
CREATE VARIABLE svar int;
DO $$
BEGIN
FOR i IN 1..10000
LOOP
LET svar = i;
END LOOP;
END;
$$;
From 120ms to 8ms (with assertions) (this is best case, but without it, the LET statement
can be bottle neck).
An alternative can be reimplementation of LET statement inside expression
executor, and then SQL LET command can be executed in simple expression
execution, but this increase an complexity of executor, but still the
benefits is only inside plpgsql, so it is better to this optimization
inside plpgsql.
---
src/backend/commands/session_variable.c | 16 ++++++
src/backend/executor/spi.c | 3 +
src/backend/parser/analyze.c | 12 ++++
src/backend/parser/gram.y | 8 +++
src/backend/parser/parser.c | 1 +
src/include/commands/session_variable.h | 1 +
src/include/nodes/parsenodes.h | 2 +
src/include/parser/parser.h | 4 ++
src/pl/plpgsql/src/pl_exec.c | 56 +++++++++++++++++++
src/pl/plpgsql/src/pl_funcs.c | 21 +++++++
src/pl/plpgsql/src/pl_gram.y | 29 +++++++++-
src/pl/plpgsql/src/pl_reserved_kwlist.h | 1 +
src/pl/plpgsql/src/pl_unreserved_kwlist.h | 1 +
src/pl/plpgsql/src/plpgsql.h | 12 ++++
.../regress/expected/session_variables.out | 6 +-
src/tools/pgindent/typedefs.list | 1 +
16 files changed, 169 insertions(+), 5 deletions(-)
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 367751ed344..554b8795569 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -948,6 +948,22 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
set_session_variable(svar, value, isNull);
}
+/*
+ * Wrapper around SetSessionVariable with permission checks.
+ */
+void
+SetSessionVariableWithSecurityCheck(Oid varid, Datum value, bool isNull)
+{
+ AclResult aclresult;
+
+ /* is the caller allowed to update the session variable? */
+ aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid));
+
+ SetSessionVariable(varid, value, isNull);
+}
+
/*
* Returns a copy of the value stored in a variable.
*/
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index ecb2e4ccaa1..a775d4fb3bd 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -2991,6 +2991,9 @@ _SPI_error_callback(void *arg)
case RAW_PARSE_PLPGSQL_ASSIGN3:
errcontext("PL/pgSQL assignment \"%s\"", query);
break;
+ case RAW_PARSE_PLPGSQL_LET:
+ errcontext("LET statement \"%s\"", query);
+ break;
default:
errcontext("SQL statement \"%s\"", query);
break;
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 46a22ff5c94..2de0d23c8e3 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -2012,6 +2012,18 @@ transformLetStmt(ParseState *pstate, LetStmt *stmt)
stmt->query = (Node *) query;
+ /*
+ * Inside PL/pgSQL we don't want to execute LET statement as utility
+ * command, because it disallow to execute expression as simple
+ * expression. So for PL/pgSQL we have extra path, and we return SELECT.
+ * Then it can be executed by exec_eval_expr. Result is dirrectly assigned
+ * to target session variable inside PL/pgSQL LET statement handler. This
+ * is extra code, extra path, but possibility to get faster execution is
+ * too attractive.
+ */
+ if (stmt->plpgsql_mode)
+ return query;
+
/* represent the command as a utility Query */
result = makeNode(Query);
result->commandType = CMD_UTILITY;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 11ae96a4397..8e86904b6aa 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -824,6 +824,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%token MODE_PLPGSQL_ASSIGN1
%token MODE_PLPGSQL_ASSIGN2
%token MODE_PLPGSQL_ASSIGN3
+%token MODE_PLPGSQL_LET
/* Precedence: lowest to highest */
@@ -955,6 +956,13 @@ parse_toplevel:
pg_yyget_extra(yyscanner)->parsetree =
list_make1(makeRawStmt((Node *) n, @2));
}
+ | MODE_PLPGSQL_LET LetStmt
+ {
+ LetStmt *n = (LetStmt *) $2;
+ n->plpgsql_mode = true;
+ pg_yyget_extra(yyscanner)->parsetree =
+ list_make1(makeRawStmt((Node *) n, 0));
+ }
;
/*
diff --git a/src/backend/parser/parser.c b/src/backend/parser/parser.c
index 33a040506b4..887212aefde 100644
--- a/src/backend/parser/parser.c
+++ b/src/backend/parser/parser.c
@@ -62,6 +62,7 @@ raw_parser(const char *str, RawParseMode mode)
[RAW_PARSE_PLPGSQL_ASSIGN1] = MODE_PLPGSQL_ASSIGN1,
[RAW_PARSE_PLPGSQL_ASSIGN2] = MODE_PLPGSQL_ASSIGN2,
[RAW_PARSE_PLPGSQL_ASSIGN3] = MODE_PLPGSQL_ASSIGN3,
+ [RAW_PARSE_PLPGSQL_LET] = MODE_PLPGSQL_LET,
};
yyextra.have_lookahead = true;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index f66b6c0b864..b89728ead5a 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -28,6 +28,7 @@ extern void AtEOSubXact_SessionVariables(bool isCommit, SubTransactionId mySubid
SubTransactionId parentSubid);
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
+extern void SetSessionVariableWithSecurityCheck(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
extern Datum GetSessionVariableWithTypeid(Oid varid, bool *isNull, Oid *typid);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 6bcaf480576..263b63a37af 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2168,6 +2168,8 @@ typedef struct LetStmt
NodeTag type;
List *target; /* target variable */
Node *query; /* source expression */
+ bool plpgsql_mode; /* true, when command will be executed
+ * (parsed) by plpgsql runtime */
ParseLoc location;
} LetStmt;
diff --git a/src/include/parser/parser.h b/src/include/parser/parser.h
index 350196cd641..c8d5e8dbf92 100644
--- a/src/include/parser/parser.h
+++ b/src/include/parser/parser.h
@@ -33,6 +33,9 @@
* RAW_PARSE_PLPGSQL_ASSIGNn: parse a PL/pgSQL assignment statement,
* and return a one-element List containing a RawStmt node. "n"
* gives the number of dotted names comprising the target ColumnRef.
+ *
+ * RAW_PARSE_PLPGSQL_LET: parse a LET statement, and return a
+ * one-element List containing a RawStmt node.
*/
typedef enum
{
@@ -42,6 +45,7 @@ typedef enum
RAW_PARSE_PLPGSQL_ASSIGN1,
RAW_PARSE_PLPGSQL_ASSIGN2,
RAW_PARSE_PLPGSQL_ASSIGN3,
+ RAW_PARSE_PLPGSQL_LET,
} RawParseMode;
/* Values for the backslash_quote GUC */
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index d4377ceecbf..05eb4ac4f32 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -22,6 +22,7 @@
#include "access/tupconvert.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "commands/session_variable.h"
#include "executor/execExpr.h"
#include "executor/spi.h"
#include "executor/tstoreReceiver.h"
@@ -333,6 +334,8 @@ static int exec_stmt_commit(PLpgSQL_execstate *estate,
PLpgSQL_stmt_commit *stmt);
static int exec_stmt_rollback(PLpgSQL_execstate *estate,
PLpgSQL_stmt_rollback *stmt);
+static int exec_stmt_let(PLpgSQL_execstate *estate,
+ PLpgSQL_stmt_let *let);
static void plpgsql_estate_setup(PLpgSQL_execstate *estate,
PLpgSQL_function *func,
@@ -2132,6 +2135,10 @@ exec_stmts(PLpgSQL_execstate *estate, List *stmts)
rc = exec_stmt_rollback(estate, (PLpgSQL_stmt_rollback *) stmt);
break;
+ case PLPGSQL_STMT_LET:
+ rc = exec_stmt_let(estate, (PLpgSQL_stmt_let *) stmt);
+ break;
+
default:
/* point err_stmt to parent, since this one seems corrupt */
estate->err_stmt = save_estmt;
@@ -5009,6 +5016,55 @@ exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt)
return PLPGSQL_RC_OK;
}
+/* ----------
+ * exec_stmt_let Evaluate an expression and
+ * put the result into a session variable.
+ * ----------
+ */
+static int
+exec_stmt_let(PLpgSQL_execstate *estate, PLpgSQL_stmt_let *stmt)
+{
+ bool isNull;
+ Oid valtype;
+ int32 valtypmod;
+ Datum value;
+ Oid varid;
+
+ List *plansources;
+ CachedPlanSource *plansource;
+
+ value = exec_eval_expr(estate,
+ stmt->expr,
+ &isNull,
+ &valtype,
+ &valtypmod);
+
+ /*
+ * Oid of target session variable is stored in Query structure. It is
+ * safer to read this value directly from the plan than to hold this value
+ * in the plpgsql context, because it's not necessary to handle
+ * invalidation of the cached value. Next operations are read only without
+ * any allocations, so we can expect that retrieving varid from Query
+ * should be fast.
+ */
+ plansources = SPI_plan_get_plan_sources(stmt->expr->plan);
+ if (list_length(plansources) != 1)
+ elog(ERROR, "unexpected length of plansources of query for LET statement");
+
+ plansource = (CachedPlanSource *) linitial(plansources);
+ if (list_length(plansource->query_list) != 1)
+ elog(ERROR, "unexpected length of plansource of query for LET statement");
+
+ varid = linitial_node(Query, plansource->query_list)->resultVariable;
+ if (!OidIsValid(varid))
+ elog(ERROR, "oid of target session variable is not valid");
+
+ SetSessionVariableWithSecurityCheck(varid, value, isNull);
+ exec_eval_cleanup(estate);
+
+ return PLPGSQL_RC_OK;
+}
+
/* ----------
* exec_assign_expr Put an expression's result into a variable.
* ----------
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index 6b5394fc5fa..242b57f76de 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -288,6 +288,8 @@ plpgsql_stmt_typename(PLpgSQL_stmt *stmt)
return "COMMIT";
case PLPGSQL_STMT_ROLLBACK:
return "ROLLBACK";
+ case PLPGSQL_STMT_LET:
+ return "LET";
}
return "unknown";
@@ -585,6 +587,13 @@ plpgsql_statement_tree_walker_impl(PLpgSQL_stmt *stmt,
E_WALK(cstmt->expr);
break;
}
+ case PLPGSQL_STMT_LET:
+ {
+ PLpgSQL_stmt_let *lstmt = (PLpgSQL_stmt_let *) stmt;
+
+ E_WALK(lstmt->expr);
+ break;
+ }
case PLPGSQL_STMT_COMMIT:
case PLPGSQL_STMT_ROLLBACK:
{
@@ -806,6 +815,7 @@ static void dump_perform(PLpgSQL_stmt_perform *stmt);
static void dump_call(PLpgSQL_stmt_call *stmt);
static void dump_commit(PLpgSQL_stmt_commit *stmt);
static void dump_rollback(PLpgSQL_stmt_rollback *stmt);
+static void dump_let(PLpgSQL_stmt_let *stmt);
static void dump_expr(PLpgSQL_expr *expr);
@@ -905,6 +915,9 @@ dump_stmt(PLpgSQL_stmt *stmt)
case PLPGSQL_STMT_ROLLBACK:
dump_rollback((PLpgSQL_stmt_rollback *) stmt);
break;
+ case PLPGSQL_STMT_LET:
+ dump_let((PLpgSQL_stmt_let *) stmt);
+ break;
default:
elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
break;
@@ -1581,6 +1594,14 @@ dump_getdiag(PLpgSQL_stmt_getdiag *stmt)
printf("\n");
}
+static void
+dump_let(PLpgSQL_stmt_let *stmt)
+{
+ dump_ind();
+ dump_expr(stmt->expr);
+ printf("\n");
+}
+
static void
dump_expr(PLpgSQL_expr *expr)
{
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index 8048e040f81..980ebb56a45 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -210,7 +210,7 @@ static void check_raise_parameters(PLpgSQL_stmt_raise *stmt);
%type <stmt> stmt_return stmt_raise stmt_assert stmt_execsql
%type <stmt> stmt_dynexecute stmt_for stmt_perform stmt_call stmt_getdiag
%type <stmt> stmt_open stmt_fetch stmt_move stmt_close stmt_null
-%type <stmt> stmt_commit stmt_rollback
+%type <stmt> stmt_commit stmt_rollback stmt_let
%type <stmt> stmt_case stmt_foreach_a
%type <list> proc_exceptions
@@ -317,6 +317,7 @@ static void check_raise_parameters(PLpgSQL_stmt_raise *stmt);
%token <keyword> K_INTO
%token <keyword> K_IS
%token <keyword> K_LAST
+%token <keyword> K_LET
%token <keyword> K_LOG
%token <keyword> K_LOOP
%token <keyword> K_MERGE
@@ -891,6 +892,8 @@ proc_stmt : pl_block ';'
{ $$ = $1; }
| stmt_rollback
{ $$ = $1; }
+ | stmt_let
+ { $$ = $1; }
;
stmt_perform : K_PERFORM
@@ -1010,6 +1013,30 @@ stmt_assign : T_DATUM
}
;
+stmt_let : K_LET
+ {
+ PLpgSQL_stmt_let *new;
+ RawParseMode pmode;
+
+ pmode = RAW_PARSE_PLPGSQL_LET;
+
+ new = palloc0(sizeof(PLpgSQL_stmt_let));
+ new->cmd_type = PLPGSQL_STMT_LET;
+ new->lineno = plpgsql_location_to_lineno(@1, yyscanner);
+ new->stmtid = ++plpgsql_curr_compile->nstatements;
+
+ /* push back the head name to include it in the stmt */
+ plpgsql_push_back_token(K_LET, &yylval, &yylloc, yyscanner);
+ new->expr = read_sql_construct(';', 0, 0, ";",
+ pmode,
+ false, true,
+ NULL, NULL,
+ &yylval, &yylloc, yyscanner);
+
+ $$ = (PLpgSQL_stmt *)new;
+ }
+ ;
+
stmt_getdiag : K_GET getdiag_area_opt K_DIAGNOSTICS getdiag_list ';'
{
PLpgSQL_stmt_getdiag *new;
diff --git a/src/pl/plpgsql/src/pl_reserved_kwlist.h b/src/pl/plpgsql/src/pl_reserved_kwlist.h
index ce7b0c9d331..e266bd1cc46 100644
--- a/src/pl/plpgsql/src/pl_reserved_kwlist.h
+++ b/src/pl/plpgsql/src/pl_reserved_kwlist.h
@@ -40,6 +40,7 @@ PG_KEYWORD("from", K_FROM)
PG_KEYWORD("if", K_IF)
PG_KEYWORD("in", K_IN)
PG_KEYWORD("into", K_INTO)
+PG_KEYWORD("let", K_LET)
PG_KEYWORD("loop", K_LOOP)
PG_KEYWORD("not", K_NOT)
PG_KEYWORD("null", K_NULL)
diff --git a/src/pl/plpgsql/src/pl_unreserved_kwlist.h b/src/pl/plpgsql/src/pl_unreserved_kwlist.h
index 98f99ec470c..ed14fd86c31 100644
--- a/src/pl/plpgsql/src/pl_unreserved_kwlist.h
+++ b/src/pl/plpgsql/src/pl_unreserved_kwlist.h
@@ -69,6 +69,7 @@ PG_KEYWORD("info", K_INFO)
PG_KEYWORD("insert", K_INSERT)
PG_KEYWORD("is", K_IS)
PG_KEYWORD("last", K_LAST)
+PG_KEYWORD("let", K_LET)
PG_KEYWORD("log", K_LOG)
PG_KEYWORD("merge", K_MERGE)
PG_KEYWORD("message", K_MESSAGE)
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index d73996e09c0..c7538612f1a 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -128,6 +128,7 @@ typedef enum PLpgSQL_stmt_type
PLPGSQL_STMT_CALL,
PLPGSQL_STMT_COMMIT,
PLPGSQL_STMT_ROLLBACK,
+ PLPGSQL_STMT_LET,
} PLpgSQL_stmt_type;
/*
@@ -542,6 +543,17 @@ typedef struct PLpgSQL_stmt_assign
PLpgSQL_expr *expr;
} PLpgSQL_stmt_assign;
+/*
+ * Let statement
+ */
+typedef struct PLpgSQL_stmt_let
+{
+ PLpgSQL_stmt_type cmd_type;
+ int lineno;
+ unsigned int stmtid;
+ PLpgSQL_expr *expr;
+} PLpgSQL_stmt_let;
+
/*
* PERFORM statement
*/
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index d0658116683..c25d804f8c1 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1129,8 +1129,7 @@ ERROR: permission denied for session variable var1
CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: SQL statement "LET var1.a = var1.a + 10"
-PL/pgSQL function inline_code_block line 1 at SQL statement
+CONTEXT: PL/pgSQL function inline_code_block line 1 at LET
SET ROLE TO DEFAULT;
GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
SET ROLE TO regress_var_test_role;
@@ -1174,8 +1173,7 @@ ERROR: permission denied for session variable var1
CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: SQL statement "LET var1.a = var1.a + 10"
-PL/pgSQL function inline_code_block line 1 at SQL statement
+CONTEXT: PL/pgSQL function inline_code_block line 1 at LET
SET ROLE TO DEFAULT;
DROP VARIABLE var1;
DROP TABLE vartesttab;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index a2147df28b3..d559087c68f 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1898,6 +1898,7 @@ PLpgSQL_stmt_forq
PLpgSQL_stmt_fors
PLpgSQL_stmt_getdiag
PLpgSQL_stmt_if
+PLpgSQL_stmt_let
PLpgSQL_stmt_loop
PLpgSQL_stmt_open
PLpgSQL_stmt_perform
--
2.48.1
[text/x-patch] v20250216-0020-transactional-variables.patch (37.3K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/21-v20250216-0020-transactional-variables.patch)
download | inline diff:
From df4c14b3a1ddf8dac82e225d2b648233652a92f8 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:11:33 +0100
Subject: [PATCH 20/21] transactional variables
This commit implements transactional variables. The content of transactional
session variables is sensitive to transactions and subtransactions. Any
transactional variable holds a history of values necessary for revert. This history
is cleaned (purged) when a) we read the variable, b) when the transaction is finished.
We don't try to purge, when the last modification of a variable is from
current subtransaction, or when purge was processed in current subtransaction.
This patch is based on my work from Feb 2020 and it is related to discussion
about features related to session variables. Now, when the all features are
separated to isolated patches I can revitalize this patch, because it doesn't
increase complexity of basic patches.
Unlike other patches, this patch is without any review at this moment (Feb 2024),
but the feature should be fully functional for people who are interested about
this feature (for testing).
---
doc/src/sgml/catalogs.sgml | 12 +
doc/src/sgml/ref/create_variable.sgml | 10 +-
src/backend/catalog/pg_variable.c | 4 +
src/backend/commands/session_variable.c | 301 +++++++++++++++++-
src/backend/parser/gram.y | 50 +--
src/bin/pg_dump/pg_dump.c | 10 +-
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_dump/t/002_pg_dump.pl | 36 +++
src/bin/psql/describe.c | 4 +-
src/bin/psql/tab-complete.in.c | 5 +
src/include/catalog/pg_variable.h | 3 +
src/include/nodes/parsenodes.h | 1 +
src/include/parser/kwlist.h | 1 +
src/test/regress/expected/psql.out | 36 +--
.../regress/expected/session_variables.out | 100 ++++++
src/test/regress/sql/session_variables.sql | 58 ++++
16 files changed, 587 insertions(+), 45 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index c7a8170ddf2..1217f8f8647 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9884,6 +9884,18 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry><structfield>varistransact</structfield></entry>
+ <entry><type>boolean</type></entry>
+ <entry></entry>
+ <entry>
+ True, when the variable is <quote>transactional</quote>. In the case
+ of a transaction rollback, transactional variables are reset to the
+ value they had when the transaction started. The default value is
+ <literal>false</literal>.
+ </entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>vareoxaction</structfield> <type>char</type>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index 3c3e6d55b69..1aadd3677e5 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -26,7 +26,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-CREATE [ { TEMPORARY | TEMP } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+CREATE [ { TEMPORARY | TEMP } ] [ { TRANSACTIONAL | TRANSACTION } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
[ NOT NULL ] [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
@@ -47,6 +47,14 @@ CREATE [ { TEMPORARY | TEMP } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replac
same as regular variables in procedural languages.
</para>
+ <para>
+ When a schema variable is created with a
+ <command>CREATE TRANSACTIONAL VARIABLE</command> command, the variables
+ content changes are transactional: in case of rollback, they are reset to
+ their value at the beginning of the transaction or the latest subtransaction.
+ The variable content is only hold in memory, and thus is not persistent.
+ </para>
+
<para>
Session variables are retrieved by the <command>SELECT</command>
command. Their value is set with the <command>LET</command> command.
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 0b6093a00ba..fa49e7233d5 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -42,6 +42,7 @@ static ObjectAddress create_variable(const char *varName,
bool if_not_exists,
bool not_null,
bool is_immutable,
+ bool is_transact,
Node *varDefexpr,
VariableXactEndAction varXactEndAction);
@@ -59,6 +60,7 @@ create_variable(const char *varName,
bool if_not_exists,
bool not_null,
bool is_immutable,
+ bool is_transact,
Node *varDefexpr,
VariableXactEndAction varXactEndAction)
{
@@ -123,6 +125,7 @@ create_variable(const char *varName,
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
values[Anum_pg_variable_varnotnull - 1] = BoolGetDatum(not_null);
values[Anum_pg_variable_varisimmutable - 1] = BoolGetDatum(is_immutable);
+ values[Anum_pg_variable_varistransact - 1] = BoolGetDatum(is_transact);
values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
if (varDefexpr)
@@ -267,6 +270,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
stmt->if_not_exists,
stmt->not_null,
stmt->is_immutable,
+ stmt->is_transact,
cooked_default,
stmt->XactEndAction);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 554b8795569..9b41ed1af62 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -47,6 +47,19 @@ typedef struct SVariableXActDropItem
SubTransactionId deleting_subid;
} SVariableXActDropItem;
+/*
+ * Used for transactional variables. Holds prev version.
+ */
+typedef struct PrevValue
+{
+ Datum value;
+ bool isnull;
+
+ SubTransactionId modify_subid;
+
+ struct PrevValue *prev_value;
+} PrevValue;
+
/*
* The values of session variables are stored in the backend's private memory
* in the dedicated memory context SVariableMemoryContext in binary format.
@@ -68,6 +81,25 @@ typedef struct SVariableData
bool isnull;
Datum value;
+ /*
+ * We don't need stack versions modified in same subtransaction.
+ * Used by transactional variables only. The value of transactional
+ * variable can be returned immediately when modify_subid is same
+ * like current subid.
+ */
+ SubTransactionId modify_subid;
+
+ /*
+ * When the modify_subid is different than current subid, then
+ * we need to recheck versions and throw versions related to
+ * reverted transactions. When purge_subid is same like current subid
+ * we can return the value of transaction variable without this
+ * recheck.
+ */
+ SubTransactionId purge_subid;
+
+ PrevValue *prev_value;
+
Oid typid;
int16 typlen;
bool typbyval;
@@ -86,6 +118,7 @@ typedef struct SVariableData
bool not_null;
bool is_immutable;
+ bool is_transact;
bool reset_at_eox;
@@ -125,6 +158,9 @@ static bool needs_validation = false;
*/
static bool has_session_variables_with_reset_at_eox = false;
+/* true, when transactional variables was modified */
+static bool has_modified_transactional_variables = false;
+
/*
* The content of dropped session variables is not removed immediately. If
* possible, we do that at the end of the transaction. But we cannot do that
@@ -140,6 +176,7 @@ static List *xact_drop_items = NIL;
static void register_session_variable_xact_drop(Oid varid);
static void unregister_session_variable_xact_drop(Oid varid);
+static bool purge_session_variable(SVariable svar);
/*
* Callback function for session variable invalidation.
@@ -292,8 +329,25 @@ unregister_session_variable_xact_drop(Oid varid)
* Release stored value, free memory
*/
static void
-free_session_variable_value(SVariable svar)
+free_session_variable_value(SVariable svar, bool deep_free)
{
+ if (deep_free)
+ {
+ PrevValue *prev_value = svar->prev_value;
+ PrevValue *next_value;
+
+ while (prev_value)
+ {
+ if (!svar->typbyval)
+ pfree(DatumGetPointer(prev_value->value));
+
+ next_value = prev_value->prev_value;
+ pfree(prev_value);
+
+ prev_value = next_value;
+ }
+ }
+
/* clean the current value */
if (!svar->isnull)
{
@@ -390,7 +444,7 @@ remove_invalid_session_variables(bool atEOX)
{
Oid varid = svar->varid;
- free_session_variable_value(svar);
+ free_session_variable_value(svar, true);
hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
svar = NULL;
}
@@ -426,6 +480,94 @@ remove_session_variables_with_reset_at_eox(void)
has_session_variables_with_reset_at_eox = false;
}
+/*
+ * remove prev values at eox
+ */
+static void
+remove_prev_values_at_eox(bool isCommit)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ if (!sessionvars)
+ return;
+
+ /* leave quckly, when there are not that variables */
+ if (!has_modified_transactional_variables)
+ return;
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (svar->is_transact && svar->modify_subid != InvalidSubTransactionId)
+ {
+ if (isCommit)
+ {
+ if (purge_session_variable(svar))
+ {
+ PrevValue *prev_value = svar->prev_value;
+
+ while (prev_value)
+ {
+ PrevValue *current_pv = prev_value;
+
+ if (!svar->typbyval && !current_pv->isnull)
+ pfree(DatumGetPointer(current_pv->value));
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+ }
+ }
+ else
+ {
+ hash_search(sessionvars, &svar->varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ }
+ else
+ {
+ PrevValue *prev_value = svar->prev_value;
+
+ while (prev_value)
+ {
+ PrevValue *current_pv = prev_value;
+
+ if (current_pv->modify_subid == InvalidSubTransactionId)
+ break;
+
+ if (!svar->typbyval && !current_pv->isnull)
+ pfree(DatumGetPointer(current_pv->value));
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+ }
+
+ if (prev_value)
+ {
+ svar->value = prev_value->value;
+ svar->isnull = prev_value->isnull;
+
+ pfree(prev_value);
+ }
+ else
+ {
+ hash_search(sessionvars, &svar->varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ }
+
+ /* when svar is still valid (not removed from sessionvars */
+ if (svar)
+ {
+ svar->modify_subid = InvalidSubTransactionId;
+ svar->prev_value = NULL;
+ }
+ }
+ }
+
+ has_modified_transactional_variables = false;
+}
+
/*
* Perform ON COMMIT DROP for temporary session variables,
* and remove all dropped variables from memory.
@@ -473,6 +615,8 @@ AtPreEOXact_SessionVariables(bool isCommit)
remove_invalid_session_variables(true);
}
+ remove_prev_values_at_eox(isCommit);
+
/*
* We have to clean xact_drop_items. All related variables are dropped
* now, or lost inside aborted transaction.
@@ -618,6 +762,7 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
svar->not_null = varform->varnotnull;
svar->is_immutable = varform->varisimmutable;
+ svar->is_transact = varform->varistransact;
svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
svar->domain_check_extra = NULL;
@@ -643,6 +788,17 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
svar->isnull = true;
svar->value = (Datum) 0;
+ if (svar->is_transact)
+ {
+ svar->modify_subid = GetCurrentSubTransactionId();
+ has_modified_transactional_variables = true;
+ }
+ else
+ svar->modify_subid = InvalidSubTransactionId;
+
+ svar->purge_subid = InvalidSubTransactionId;
+ svar->prev_value = NULL;
+
svar->is_valid = true;
svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
@@ -676,6 +832,69 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
ReleaseSysCache(tup);
}
+/*
+ * Try to remove all previous versions related to reverted transactions.
+ * Returns true, when valid version was found.
+ */
+static bool
+purge_session_variable(SVariable svar)
+{
+ SubTransactionId current_subid;
+ PrevValue *prev_value;
+ bool found = true;
+
+ Assert(svar->is_transact);
+
+ if (svar->modify_subid == InvalidSubTransactionId)
+ return true;
+
+ current_subid = GetCurrentSubTransactionId();
+
+ if (svar->modify_subid == current_subid)
+ return true;
+
+ if (svar->purge_subid == current_subid)
+ return true;
+
+ if (SubTransactionIsActive(svar->modify_subid))
+ {
+ svar->purge_subid = current_subid;
+ return true;
+ }
+
+ prev_value = svar->prev_value;
+
+ while (prev_value)
+ {
+ PrevValue *current_pv = prev_value;
+
+ if (current_pv->modify_subid == InvalidSubTransactionId ||
+ SubTransactionIsActive(current_pv->modify_subid))
+ {
+ svar->value = current_pv->value;
+ svar->isnull = current_pv->isnull;
+ svar->modify_subid = current_pv->modify_subid;
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+
+ found = true;
+ break;
+ }
+
+ if (!svar->typbyval && !current_pv->isnull)
+ pfree(DatumGetPointer(current_pv->value));
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+ }
+
+ svar->prev_value = prev_value;
+ svar->purge_subid = current_subid;
+
+ return found;
+}
+
/*
* Assign a new value to the session variable. It is copied to
* SVariableMemoryContext if necessary.
@@ -688,6 +907,10 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
Datum newval;
SVariableData locsvar,
*_svar;
+ SubTransactionId current_subid = GetCurrentSubTransactionId();
+ SubTransactionId prev_purge_subid = InvalidSubTransactionId;
+ bool save_prev_value;
+ PrevValue *prev_value;
Assert(svar);
Assert(!isnull || value == (Datum) 0);
@@ -723,6 +946,21 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
else
_svar = svar;
+ if (_svar->is_transact && _svar->create_lsn == svar->create_lsn)
+ {
+ Assert(svar->typid == _svar->typid);
+ Assert(svar->typbyval == _svar->typbyval);
+ Assert(svar->typlen == _svar->typlen);
+
+ save_prev_value = svar->modify_subid != current_subid;
+ prev_value = svar->prev_value;
+ }
+ else
+ {
+ save_prev_value = false;
+ prev_value = NULL;
+ }
+
if (!isnull)
{
MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
@@ -734,7 +972,37 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
else
newval = value;
- free_session_variable_value(svar);
+ if (save_prev_value)
+ {
+ volatile PrevValue *new_prev_value;
+
+ PG_TRY();
+ {
+ new_prev_value = MemoryContextAlloc(SVariableMemoryContext,
+ sizeof(PrevValue));
+ }
+ PG_CATCH();
+ {
+ /* release mem from persistent content */
+ if (newval != value)
+ pfree(DatumGetPointer(newval));
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
+
+ new_prev_value->value = svar->value;
+ new_prev_value->isnull = svar->isnull;
+ new_prev_value->modify_subid = svar->modify_subid;
+ new_prev_value->prev_value = prev_value;
+
+ prev_value = (PrevValue *) new_prev_value;
+ prev_purge_subid = svar->purge_subid;
+
+ has_modified_transactional_variables = true;
+
+ }
+ else
+ free_session_variable_value(svar, prev_value == NULL);
elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value",
get_namespace_name(get_session_variable_namespace(svar->varid)),
@@ -747,6 +1015,9 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
svar->value = newval;
svar->isnull = isnull;
+ svar->modify_subid = current_subid;
+ svar->purge_subid = prev_purge_subid;
+ svar->prev_value = prev_value;
/* don't allow more changes of value when variable is IMMUTABLE */
if (svar->is_immutable)
@@ -848,6 +1119,8 @@ get_session_variable(Oid varid)
else
svar->is_valid = false;
+reinit:
+
/*
* Force setup for not yet initialized variables or variables that cannot
* be validated.
@@ -880,6 +1153,28 @@ get_session_variable(Oid varid)
varid);
}
+ /*
+ * Transactional variables should be purged before (remove
+ * versions created by possibly reverted subtransactions).
+ */
+ if (svar->is_transact &&
+ svar->modify_subid != GetCurrentSubTransactionId() &&
+ svar->modify_subid != InvalidSubTransactionId)
+ {
+ if (!purge_session_variable(svar))
+ {
+ /* force reinit */
+ svar->is_valid = false;
+
+ /*
+ * In next iteration modify_subid should be
+ * InvalidSubTransactionId or current subid,
+ * so there is not risk of infinity cycle.
+ */
+ goto reinit;
+ }
+ }
+
/* ensure the returned data is still of the correct domain */
if (svar->is_domain)
{
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 8e86904b6aa..6a898a978f7 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -675,7 +675,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
json_object_constructor_null_clause_opt
json_array_constructor_null_clause_opt
-%type <boolean> OptNotNull OptImmutable
+%type <boolean> OptNotNull OptImmutable OptTransactional
/*
* Non-keyword token types. These are hard-wired into the "flex" lexer.
@@ -780,7 +780,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
SUBSCRIPTION SUBSTRING SUPPORT SYMMETRIC SYSID SYSTEM_P SYSTEM_USER
TABLE TABLES TABLESAMPLE TABLESPACE TARGET TEMP TEMPLATE TEMPORARY TEXT_P THEN
- TIES TIME TIMESTAMP TO TRAILING TRANSACTION TRANSFORM
+ TIES TIME TIMESTAMP TO TRAILING TRANSACTION TRANSACTIONAL TRANSFORM
TREAT TRIGGER TRIM TRUE_P
TRUNCATE TRUSTED TYPE_P TYPES_P
@@ -5274,31 +5274,33 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE OptTemp OptImmutable VARIABLE qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
+ CREATE OptTemp OptTransactional OptImmutable VARIABLE qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $5->relpersistence = $2;
- n->is_immutable = $3;
- n->variable = $5;
- n->typeName = $7;
- n->collClause = (CollateClause *) $8;
- n->not_null = $9;
- n->defexpr = $10;
- n->XactEndAction = $11;
+ $6->relpersistence = $2;
+ n->is_immutable = $4;
+ n->is_transact = $3;
+ n->variable = $6;
+ n->typeName = $8;
+ n->collClause = (CollateClause *) $9;
+ n->not_null = $10;
+ n->defexpr = $11;
+ n->XactEndAction = $12;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE OptTemp OptImmutable VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
+ | CREATE OptTemp OptTransactional OptImmutable VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $8->relpersistence = $2;
- n->is_immutable = $3;
- n->variable = $8;
- n->typeName = $10;
- n->collClause = (CollateClause *) $11;
- n->not_null = $12;
- n->defexpr = $13;
- n->XactEndAction = $14;
+ $9->relpersistence = $2;
+ n->is_immutable = $4;
+ n->is_transact = $3;
+ n->variable = $9;
+ n->typeName = $11;
+ n->collClause = (CollateClause *) $12;
+ n->not_null = $13;
+ n->defexpr = $14;
+ n->XactEndAction = $15;
n->if_not_exists = true;
$$ = (Node *) n;
}
@@ -5326,6 +5328,12 @@ OptImmutable: IMMUTABLE { $$ = true; }
| /* EMPTY */ { $$ = false; }
;
+OptTransactional:
+ TRANSACTION { $$ = true; }
+ | TRANSACTIONAL { $$ = true; }
+ | /* EMPTY */ { $$ = false; }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
@@ -18174,6 +18182,7 @@ unreserved_keyword:
| TEXT_P
| TIES
| TRANSACTION
+ | TRANSACTIONAL
| TRANSFORM
| TRIGGER
| TRUNCATE
@@ -18824,6 +18833,7 @@ bare_label_keyword:
| TIMESTAMP
| TRAILING
| TRANSACTION
+ | TRANSACTIONAL
| TRANSFORM
| TREAT
| TRIGGER
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 47c26947c4d..e5fb07b5025 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5446,6 +5446,7 @@ getVariables(Archive *fout)
int i_varcollation;
int i_varnotnull;
int i_varisimmutable;
+ int i_varistransact;
int i_varacl;
int i_acldefault;
int i,
@@ -5468,6 +5469,7 @@ getVariables(Archive *fout)
" END AS varcollation,\n"
" v.varnotnull,\n"
" v.varisimmutable,\n"
+ " v.varistransact,\n"
" pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n"
" v.varowner, v.varacl,\n"
" acldefault('V', v.varowner) AS acldefault\n"
@@ -5490,6 +5492,7 @@ getVariables(Archive *fout)
i_varcollation = PQfnumber(res, "varcollation");
i_varnotnull = PQfnumber(res, "varnotnull");
i_varisimmutable = PQfnumber(res, "varisimmutable");
+ i_varistransact = PQfnumber(res, "varistransact");
i_varowner = PQfnumber(res, "varowner");
i_varacl = PQfnumber(res, "varacl");
@@ -5518,6 +5521,7 @@ getVariables(Archive *fout)
varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
varinfo[i].varnotnull = *(PQgetvalue(res, i, i_varnotnull)) == 't';
varinfo[i].varisimmutable = *(PQgetvalue(res, i, i_varisimmutable)) == 't';
+ varinfo[i].varistransact = *(PQgetvalue(res, i, i_varistransact)) == 't';
varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
@@ -5565,6 +5569,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
const char *vardefexpr;
const char *varxactendaction;
const char *varisimmutable;
+ const char *varistransact;
Oid varcollation;
bool varnotnull;
@@ -5582,12 +5587,13 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
varcollation = varinfo->varcollation;
varnotnull = varinfo->varnotnull;
varisimmutable = varinfo->varisimmutable ? "IMMUTABLE " : "";
+ varistransact = varinfo->varistransact ? "TRANSACTIONAL " : "";
appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
qualvarname);
- appendPQExpBuffer(query, "CREATE %sVARIABLE %s AS %s",
- varisimmutable, qualvarname, vartypname);
+ appendPQExpBuffer(query, "CREATE %s%sVARIABLE %s AS %s",
+ varistransact, varisimmutable, qualvarname, vartypname);
if (OidIsValid(varcollation))
{
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index 0ae406f8551..12af34547c1 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -724,6 +724,7 @@ typedef struct _VariableInfo
const char *rolname; /* name of owner, or empty string */
bool varnotnull;
bool varisimmutable;
+ bool varistransact;
} VariableInfo;
/*
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 5f80bd4e79a..e00a979ee6a 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4144,6 +4144,42 @@ my %tests = (
},
},
+ 'CREATE TRANSACTIONAL VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE TRANSACTIONAL VARIABLE dump_test.variable8 AS integer',
+ regexp => qr/^
+ \QCREATE TRANSACTIONAL VARIABLE dump_test.variable8 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
+ 'CREATE TRANSACTIONAL IMMUTABLE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE TRANSACTIONAL IMMUTABLE VARIABLE dump_test.variable9 AS integer',
+ regexp => qr/^
+ \QCREATE TRANSACTIONAL IMMUTABLE VARIABLE dump_test.variable9 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 07835aa2bab..119986886e8 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5354,6 +5354,7 @@ listVariables(const char *pattern, bool verbose)
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
" NOT v.varnotnull as \"%s\",\n"
" NOT v.varisimmutable as \"%s\",\n"
+ " v.varistransact as \"%s\",\n"
" pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
@@ -5366,6 +5367,7 @@ listVariables(const char *pattern, bool verbose)
gettext_noop("Owner"),
gettext_noop("Nullable"),
gettext_noop("Mutable"),
+ gettext_noop("Transactional"),
gettext_noop("Default"),
gettext_noop("Transactional end action"));
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index f547bce1a10..c46078a700e 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1305,6 +1305,8 @@ static const pgsql_thing_t words_after_create[] = {
* TABLE ... */
{"TEXT SEARCH", NULL, NULL, NULL},
{"TRANSFORM", NULL, NULL, NULL, NULL, THING_NO_ALTER},
+ {"TRANSACTIONAL", NULL, NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE TRANSACTIONAL
+ * VARIABLE ... */
{"TRIGGER", "SELECT tgname FROM pg_catalog.pg_trigger WHERE tgname LIKE '%s' AND NOT tgisinternal"},
{"TYPE", NULL, NULL, &Query_for_list_of_datatypes},
{"UNIQUE", NULL, NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE UNIQUE
@@ -3966,8 +3968,11 @@ match_previous_words(int pattern_id,
}
/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE VARIABLE <name> with AS */
+ else if (Matches("CREATE", "TRANSACTION|TRANSACTIONAL"))
+ COMPLETE_WITH("IMMUTABLE", "VARIABLE");
else if (TailMatches("CREATE", "VARIABLE", MatchAny) ||
TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny) ||
+ TailMatches("TRANSACTION|TRANSACTIONAL", "VARIABLE", MatchAny) ||
TailMatches("IMMUTABLE", "VARIABLE", MatchAny))
COMPLETE_WITH("AS");
else if (TailMatches("VARIABLE", MatchAny, "AS"))
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index cf21e0426a7..454bb297097 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -62,6 +62,9 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* don't allow changes */
bool varisimmutable BKI_DEFAULT(f);
+ /* supports transactions */
+ bool varistransact BKI_DEFAULT(f);
+
/* action on transaction end */
char varxactendaction BKI_DEFAULT(n);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 263b63a37af..d72d12d820f 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3539,6 +3539,7 @@ typedef struct CreateSessionVarStmt
bool if_not_exists; /* do nothing if it already exists */
bool not_null; /* disallow nulls */
bool is_immutable; /* don't allow changes */
+ bool is_transact; /* supports transactions */
Node *defexpr; /* default expression */
char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 431167f6b43..e19b957739f 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -456,6 +456,7 @@ PG_KEYWORD("timestamp", TIMESTAMP, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("to", TO, RESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("trailing", TRAILING, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("transaction", TRANSACTION, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("transactional", TRANSACTIONAL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("transform", TRANSFORM, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("treat", TREAT, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("trigger", TRIGGER, UNRESERVED_KEYWORD, BARE_LABEL)
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index ec870172faa..061307621cd 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6020,20 +6020,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | t | t | | | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------------+---------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | f | | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | t | t | | | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------------+---------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | f | | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6501,9 +6501,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
---------+------+------+-----------+-------+----------+---------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------------+---------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6676,9 +6676,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
---------+------+------+-----------+-------+----------+---------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------------+---------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6815,9 +6815,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
---------+------+------+-----------+-------+----------+---------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------------+---------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7b71bba90e9..9059e6bc249 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2502,3 +2502,103 @@ SELECT var1;
LET var1 = 30;
ERROR: session variable "public.var1" is declared IMMUTABLE
DROP VARIABLE var1;
+-- test transactional variables
+CREATE TRANSACTION VARIABLE tv AS int DEFAULT 0;
+BEGIN;
+ LET tv = 100;
+ SELECT tv;
+ tv
+-----
+ 100
+(1 row)
+
+ROLLBACK;
+SELECT tv;
+ tv
+----
+ 0
+(1 row)
+
+LET tv = 100;
+BEGIN;
+ LET tv = 1000;
+COMMIT;
+SELECT tv;
+ tv
+------
+ 1000
+(1 row)
+
+BEGIN;
+ LET tv = 0;
+ SELECT tv;
+ tv
+----
+ 0
+(1 row)
+
+ROLLBACK;
+SELECT tv;
+ tv
+------
+ 1000
+(1 row)
+
+-- test subtransactions
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ tv
+----
+ 2
+(1 row)
+
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+ tv
+----
+ 1
+(1 row)
+
+ROLLBACK;
+SELECT tv;
+ tv
+------
+ 1000
+(1 row)
+
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ tv
+----
+ 2
+(1 row)
+
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+ tv
+----
+ 1
+(1 row)
+
+COMMIT;
+SELECT tv;
+ tv
+----
+ 1
+(1 row)
+
+DROP VARIABLE tv;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index c8c2295adbd..880f60e9917 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1735,3 +1735,61 @@ SELECT var1;
LET var1 = 30;
DROP VARIABLE var1;
+
+-- test transactional variables
+CREATE TRANSACTION VARIABLE tv AS int DEFAULT 0;
+
+BEGIN;
+ LET tv = 100;
+ SELECT tv;
+ROLLBACK;
+
+SELECT tv;
+
+LET tv = 100;
+BEGIN;
+ LET tv = 1000;
+COMMIT;
+
+SELECT tv;
+
+BEGIN;
+ LET tv = 0;
+ SELECT tv;
+ROLLBACK;
+
+SELECT tv;
+
+-- test subtransactions
+
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+ROLLBACK;
+
+SELECT tv;
+
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+COMMIT;
+
+SELECT tv;
+
+DROP VARIABLE tv;
--
2.48.1
[text/x-patch] v20250216-0021-pg_restore-A-variable.patch (2.8K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/22-v20250216-0021-pg_restore-A-variable.patch)
download | inline diff:
From b8ee2c3ef9178e6b1083658d136434b0c3305ece Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sun, 21 Jul 2024 17:04:41 +0200
Subject: [PATCH 21/21] pg_restore -A, --variable
possibility to restore session variable specified by name
---
doc/src/sgml/ref/pg_restore.sgml | 11 +++++++++++
src/bin/pg_dump/pg_restore.c | 9 ++++++++-
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/doc/src/sgml/ref/pg_restore.sgml b/doc/src/sgml/ref/pg_restore.sgml
index b8b27e1719e..7a3a4eabe25 100644
--- a/doc/src/sgml/ref/pg_restore.sgml
+++ b/doc/src/sgml/ref/pg_restore.sgml
@@ -106,6 +106,17 @@ PostgreSQL documentation
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>-A <replaceable class="parameter">session_variable</replaceable></option></term>
+ <term><option>--variable=<replaceable class="parameter">session_variable</replaceable></option></term>
+ <listitem>
+ <para>
+ Restore a named session variable only. Multiple session variables may
+ be specified with multiple <option>-A</option> switches.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>-c</option></term>
<term><option>--clean</option></term>
diff --git a/src/bin/pg_dump/pg_restore.c b/src/bin/pg_dump/pg_restore.c
index c602272d7db..02becb4179a 100644
--- a/src/bin/pg_dump/pg_restore.c
+++ b/src/bin/pg_dump/pg_restore.c
@@ -106,6 +106,7 @@ main(int argc, char **argv)
{"trigger", 1, NULL, 'T'},
{"use-list", 1, NULL, 'L'},
{"username", 1, NULL, 'U'},
+ {"variable", 1, NULL, 'A'},
{"verbose", 0, NULL, 'v'},
{"single-transaction", 0, NULL, '1'},
@@ -156,7 +157,7 @@ main(int argc, char **argv)
}
}
- while ((c = getopt_long(argc, argv, "acCd:ef:F:h:I:j:lL:n:N:Op:P:RsS:t:T:U:vwWx1",
+ while ((c = getopt_long(argc, argv, "A:acCd:ef:F:h:I:j:lL:n:N:Op:P:RsS:t:T:U:vwWx1",
cmdopts, NULL)) != -1)
{
switch (c)
@@ -164,6 +165,11 @@ main(int argc, char **argv)
case 'a': /* Dump data only */
data_only = true;
break;
+ case 'A': /* vAriable */
+ opts->selTypes = 1;
+ opts->selVariable = 1;
+ simple_string_list_append(&opts->variableNames, optarg);
+ break;
case 'c': /* clean (i.e., drop) schema prior to create */
opts->dropSchema = 1;
break;
@@ -466,6 +472,7 @@ usage(const char *progname)
printf(_("\nOptions controlling the restore:\n"));
printf(_(" -a, --data-only restore only the data, no schema\n"));
+ printf(_(" -A, --variable=NAME restore named session variable\n"));
printf(_(" -c, --clean clean (drop) database objects before recreating\n"));
printf(_(" -C, --create create the target database\n"));
printf(_(" -e, --exit-on-error exit on error, default is to continue\n"));
--
2.48.1
[text/x-patch] v20250216-0001-Enhancing-catalog-for-support-session-variables-and-.patch (169.2K, ../../CAFj8pRBpmcV3kdoORvz1iB52otW6FRVP7CBK_bLMsGiONDMM3Q@mail.gmail.com/23-v20250216-0001-Enhancing-catalog-for-support-session-variables-and-.patch)
download | inline diff:
From 1e5d54f443d20646a167e7e65b6a8dd0b1454936 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 15:41:55 +0100
Subject: [PATCH 01/21] Enhancing catalog for support session variables and
related support
This patch introduces new system catalog table pg_variable. This table holds metadata about
session variables created by command CREATE VARIABLE, and dropped by command DROP VARIABLE.
Both commands are implemented by this patch. Possibility to change owner, schema or rename.
Access to session variables can be controlled by SELECT or UPDATE rights. Both rights are
introduced by this patch too.
This patch enhancing pg_dump and psql to support session variables. The changes are related
to system catalog.
This patch is not short, but the code is simple.
---
doc/src/sgml/catalogs.sgml | 123 ++++-
doc/src/sgml/ddl.sgml | 40 +-
doc/src/sgml/func.sgml | 32 ++
doc/src/sgml/glossary.sgml | 15 +
doc/src/sgml/ref/allfiles.sgml | 3 +
.../sgml/ref/alter_default_privileges.sgml | 27 +-
doc/src/sgml/ref/alter_variable.sgml | 178 +++++++
doc/src/sgml/ref/comment.sgml | 1 +
doc/src/sgml/ref/create_schema.sgml | 12 +-
doc/src/sgml/ref/create_variable.sgml | 149 ++++++
doc/src/sgml/ref/drop_variable.sgml | 117 +++++
doc/src/sgml/ref/grant.sgml | 20 +-
doc/src/sgml/ref/psql-ref.sgml | 13 +
doc/src/sgml/ref/revoke.sgml | 8 +
doc/src/sgml/reference.sgml | 3 +
src/backend/catalog/Makefile | 1 +
src/backend/catalog/aclchk.c | 77 ++++
src/backend/catalog/dependency.c | 6 +
src/backend/catalog/meson.build | 1 +
src/backend/catalog/namespace.c | 221 +++++++++
src/backend/catalog/objectaddress.c | 121 ++++-
src/backend/catalog/pg_shdepend.c | 2 +
src/backend/catalog/pg_variable.c | 251 ++++++++++
src/backend/commands/alter.c | 9 +
src/backend/commands/dropcmds.c | 4 +
src/backend/commands/event_trigger.c | 4 +
src/backend/commands/seclabel.c | 1 +
src/backend/commands/tablecmds.c | 41 ++
src/backend/commands/typecmds.c | 15 +
src/backend/parser/gram.y | 105 ++++-
src/backend/parser/parse_utilcmd.c | 12 +
src/backend/tcop/utility.c | 20 +
src/backend/utils/adt/acl.c | 221 +++++++++
src/backend/utils/cache/lsyscache.c | 113 +++++
src/bin/pg_dump/common.c | 3 +
src/bin/pg_dump/dumputils.c | 6 +
src/bin/pg_dump/pg_backup.h | 2 +
src/bin/pg_dump/pg_backup_archiver.c | 9 +
src/bin/pg_dump/pg_dump.c | 190 ++++++++
src/bin/pg_dump/pg_dump.h | 15 +
src/bin/pg_dump/pg_dump_sort.c | 6 +
src/bin/pg_dump/t/002_pg_dump.pl | 64 +++
src/bin/psql/command.c | 3 +
src/bin/psql/describe.c | 100 +++-
src/bin/psql/describe.h | 3 +
src/bin/psql/help.c | 1 +
src/bin/psql/tab-complete.in.c | 43 +-
src/include/catalog/Makefile | 3 +-
src/include/catalog/meson.build | 1 +
src/include/catalog/namespace.h | 6 +
src/include/catalog/pg_default_acl.h | 1 +
src/include/catalog/pg_proc.dat | 23 +
src/include/catalog/pg_variable.h | 81 ++++
src/include/nodes/parsenodes.h | 16 +
src/include/parser/kwlist.h | 2 +
src/include/tcop/cmdtaglist.h | 3 +
src/include/utils/acl.h | 1 +
src/include/utils/lsyscache.h | 9 +
src/test/regress/expected/dependency.out | 17 +
src/test/regress/expected/oidjoins.out | 4 +
src/test/regress/expected/psql.out | 50 ++
.../regress/expected/session_variables.out | 433 ++++++++++++++++++
src/test/regress/parallel_schedule | 2 +-
src/test/regress/sql/dependency.sql | 14 +
src/test/regress/sql/psql.sql | 21 +
src/test/regress/sql/session_variables.sql | 297 ++++++++++++
src/tools/pgindent/typedefs.list | 4 +
67 files changed, 3363 insertions(+), 36 deletions(-)
create mode 100644 doc/src/sgml/ref/alter_variable.sgml
create mode 100644 doc/src/sgml/ref/create_variable.sgml
create mode 100644 doc/src/sgml/ref/drop_variable.sgml
create mode 100644 src/backend/catalog/pg_variable.c
create mode 100644 src/include/catalog/pg_variable.h
create mode 100644 src/test/regress/expected/session_variables.out
create mode 100644 src/test/regress/sql/session_variables.sql
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index ee59a7e15d0..7ba91b1f4b1 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -369,6 +369,11 @@
<entry><link linkend="catalog-pg-user-mapping"><structname>pg_user_mapping</structname></link></entry>
<entry>mappings of users to foreign servers</entry>
</row>
+
+ <row>
+ <entry><link linkend="catalog-pg-variable"><structname>pg_variable</structname></link></entry>
+ <entry>session variables</entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -3340,7 +3345,8 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
<literal>S</literal> = sequence,
<literal>f</literal> = function,
<literal>T</literal> = type,
- <literal>n</literal> = schema
+ <literal>n</literal> = schema,
+ <literal>V</literal> = session variable
</para></entry>
</row>
@@ -9758,4 +9764,119 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</table>
</sect1>
+ <sect1 id="catalog-pg-variable">
+ <title><structname>pg_variable</structname></title>
+
+ <indexterm zone="catalog-pg-variable">
+ <primary>pg_variable</primary>
+ </indexterm>
+
+ <para>
+ The catalog <structname>pg_variable</structname> stores information about
+ session variables.
+ </para>
+
+ <table>
+ <title><structname>pg_variable</structname> Columns</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ Column Type
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>oid</structfield> <type>oid</type>
+ </para>
+ <para>
+ Row identifier
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartype</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-type"><structname>pg_type</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the variable's data type
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varname</structfield> <type>name</type>
+ </para>
+ <para>
+ Name of the session variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varnamespace</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the namespace that contains this variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varowner</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ Owner of the variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartypmod</structfield> <type>int4</type>
+ </para>
+ <para>
+ <structfield>vartypmod</structfield> records type-specific data
+ supplied at variable creation time (for example, the maximum
+ length of a <type>varchar</type> column). It is passed to
+ type-specific input functions and length coercion functions.
+ The value will generally be -1 for types that do not need <structfield>vartypmod</structfield>.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcollation</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-collation"><structname>pg_collation</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The defined collation of the variable, or zero if the variable is
+ not of a collatable data type.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varacl</structfield> <type>aclitem[]</type>
+ </para>
+ <para>
+ Access privileges; see
+ <xref linkend="sql-grant"/> and
+ <xref linkend="sql-revoke"/>
+ for details
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+ </sect1>
</chapter>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index ae156b6b1cd..edfb7db24fc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -2020,6 +2020,7 @@ REVOKE ALL ON accounts FROM PUBLIC;
For sequences, this privilege also allows use of the
<function>currval</function> function.
For large objects, this privilege allows the object to be read.
+ For session variables, this privilege allows the object to be read.
</para>
</listitem>
</varlistentry>
@@ -2055,6 +2056,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<function>setval</function> functions.
For large objects, this privilege allows writing or truncating the
object.
+ For session variables, this privilege allows to set a value to the
+ object.
</para>
</listitem>
</varlistentry>
@@ -2298,7 +2301,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal> (and table-like objects),
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2313,7 +2317,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal>,
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2500,6 +2505,12 @@ REVOKE ALL ON accounts FROM PUBLIC;
<entry><literal>U</literal></entry>
<entry><literal>\dT+</literal></entry>
</row>
+ <row>
+ <entry><literal>SESSION VARIABLE</literal></entry>
+ <entry><literal>rw</literal></entry>
+ <entry><literal>none</literal></entry>
+ <entry><literal>\dV+</literal></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -5350,6 +5361,31 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
</para>
</sect1>
+ <sect1 id="ddl-session-variables">
+ <title>Session Variables</title>
+
+ <indexterm zone="ddl-session-variables">
+ <primary>Session variables</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ </indexterm>
+
+ <para>
+ Session variables are database objects that can hold a value.
+ Session variables, like relations, exist within a schema and their access
+ is controlled via <command>GRANT</command> and <command>REVOKE</command>
+ commands. A session variable can be created by the <command>CREATE
+ VARIABLE</command> command.
+ </para>
+
+ <para>
+ The session variable holds value in session memory. This value is private
+ to each session and is released when the session ends.
+ </para>
+ </sect1>
+
<sect1 id="ddl-others">
<title>Other Database Objects</title>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 7efc81936ab..4a484034c0f 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25337,6 +25337,25 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
</para></entry>
</row>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>has_session_variable_privilege</primary>
+ </indexterm>
+ <function>has_session_variable_privilege</function> (
+ <optional> <parameter>user</parameter> <type>name</type> or <type>oid</type>, </optional>
+ <parameter>session_variable</parameter> <type>text</type> or <type>oid</type>,
+ <parameter>privilege</parameter> <type>text</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Does user have privilege for session variable?
+ Allowable privilege types are
+ <literal>SELECT</literal>, and
+ <literal>UPDATE</literal>.
+ </para></entry>
+ </row>
+
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
@@ -25845,6 +25864,19 @@ SELECT relname FROM pg_class WHERE pg_table_is_visible(oid);
Is type (or domain) visible in search path?
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_variable_is_visible</primary>
+ </indexterm>
+ <function>pg_variable_is_visible</function> ( <parameter>variable</parameter> <type>oid</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Is session variable visible in search path?
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index c0f812e3f5e..b921f5a3339 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1669,6 +1669,21 @@
</glossdef>
</glossentry>
+ <glossentry id="glossary-session-variable">
+ <glossterm>Session variable</glossterm>
+ <glossdef>
+ <para>
+ A persistent database object that holds a value in session memory. This
+ value is private to each session and is released when the session ends.
+ Read or write access to session variables is controlled by privileges,
+ similar to other database objects.
+ </para>
+ <para>
+ For more information, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </glossdef>
+ </glossentry>
+
<glossentry id="glossary-shared-memory">
<glossterm>Shared memory</glossterm>
<glossdef>
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index f5be638867a..2f67de3e21b 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -47,6 +47,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY alterType SYSTEM "alter_type.sgml">
<!ENTITY alterUser SYSTEM "alter_user.sgml">
<!ENTITY alterUserMapping SYSTEM "alter_user_mapping.sgml">
+<!ENTITY alterVariable SYSTEM "alter_variable.sgml">
<!ENTITY alterView SYSTEM "alter_view.sgml">
<!ENTITY analyze SYSTEM "analyze.sgml">
<!ENTITY begin SYSTEM "begin.sgml">
@@ -99,6 +100,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY createType SYSTEM "create_type.sgml">
<!ENTITY createUser SYSTEM "create_user.sgml">
<!ENTITY createUserMapping SYSTEM "create_user_mapping.sgml">
+<!ENTITY createVariable SYSTEM "create_variable.sgml">
<!ENTITY createView SYSTEM "create_view.sgml">
<!ENTITY deallocate SYSTEM "deallocate.sgml">
<!ENTITY declare SYSTEM "declare.sgml">
@@ -147,6 +149,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY dropType SYSTEM "drop_type.sgml">
<!ENTITY dropUser SYSTEM "drop_user.sgml">
<!ENTITY dropUserMapping SYSTEM "drop_user_mapping.sgml">
+<!ENTITY dropVariable SYSTEM "drop_variable.sgml">
<!ENTITY dropView SYSTEM "drop_view.sgml">
<!ENTITY end SYSTEM "end.sgml">
<!ENTITY execute SYSTEM "execute.sgml">
diff --git a/doc/src/sgml/ref/alter_default_privileges.sgml b/doc/src/sgml/ref/alter_default_privileges.sgml
index 89aacec4fab..a5852d32566 100644
--- a/doc/src/sgml/ref/alter_default_privileges.sgml
+++ b/doc/src/sgml/ref/alter_default_privileges.sgml
@@ -51,6 +51,11 @@ GRANT { { USAGE | CREATE }
ON SCHEMAS
TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+GRANT { { SELECT | UPDATE }
+ [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+
REVOKE [ GRANT OPTION FOR ]
{ { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER | MAINTAIN }
[, ...] | ALL [ PRIVILEGES ] }
@@ -83,6 +88,12 @@ REVOKE [ GRANT OPTION FOR ]
ON SCHEMAS
FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
[ CASCADE | RESTRICT ]
+
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
+ [ CASCADE | RESTRICT ]
</synopsis>
</refsynopsisdiv>
@@ -117,14 +128,14 @@ REVOKE [ GRANT OPTION FOR ]
<para>
Currently,
only the privileges for schemas, tables (including views and foreign
- tables), sequences, functions, and types (including domains) can be
- altered. For this command, functions include aggregates and procedures.
- The words <literal>FUNCTIONS</literal> and <literal>ROUTINES</literal> are
- equivalent in this command. (<literal>ROUTINES</literal> is preferred
- going forward as the standard term for functions and procedures taken
- together. In earlier PostgreSQL releases, only the
- word <literal>FUNCTIONS</literal> was allowed. It is not possible to set
- default privileges for functions and procedures separately.)
+ tables), sequences, functions, types (including domains), and session
+ variables can be altered. For this command, functions include aggregates
+ and procedures. The words <literal>FUNCTIONS</literal> and
+ <literal>ROUTINES</literal> are equivalent in this command.
+ (<literal>ROUTINES</literal> is preferred going forward as the standard
+ term for functions and procedures taken together. In earlier PostgreSQL
+ releases, only the word <literal>FUNCTIONS</literal> was allowed. It is not
+ possible to set default privileges for functions and procedures separately.)
</para>
<para>
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
new file mode 100644
index 00000000000..96d2586423e
--- /dev/null
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -0,0 +1,178 @@
+<!--
+doc/src/sgml/ref/alter_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-altervariable">
+ <indexterm zone="sql-altervariable">
+ <primary>ALTER VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>altering</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>ALTER VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>ALTER VARIABLE</refname>
+ <refpurpose>
+ change the definition of a session variable
+ </refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable class="parameter">new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable class="parameter">new_name</replaceable>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> SET SCHEMA <replaceable class="parameter">new_schema</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>ALTER VARIABLE</command> command changes the definition of an
+ existing session variable. There are several subforms:
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>OWNER</literal></term>
+ <listitem>
+ <para>
+ This form changes the owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RENAME</literal></term>
+ <listitem>
+ <para>
+ This form changes the name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>SET SCHEMA</literal></term>
+ <listitem>
+ <para>
+ This form moves the session variable into another schema.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </para>
+
+ <para>
+ Only the owner or a superuser is allowed to alter a session variable.
+ In order to move a session variable from one schema to another, the user
+ must also have the <literal>CREATE</literal> privilege on the new schema (or
+ be a superuser).
+
+ In order to move the session variable ownership from one role to another,
+ the user must also be a direct or indirect member of the new
+ owning role, and that role must have the <literal>CREATE</literal> privilege
+ on the session variable's schema (or be a superuser). These restrictions
+ enforce that altering the owner doesn't do anything you couldn't do by
+ dropping and recreating the session variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <para>
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name (possibly schema-qualified) of the existing session variable
+ to alter.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_owner</replaceable></term>
+ <listitem>
+ <para>
+ The user name of the new owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_name</replaceable></term>
+ <listitem>
+ <para>
+ The new name for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_schema</replaceable></term>
+ <listitem>
+ <para>
+ The new schema for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To rename a session variable:
+<programlisting>
+ALTER VARIABLE foo RENAME TO boo;
+</programlisting>
+ </para>
+
+ <para>
+ To change the owner of the session variable <literal>boo</literal> to
+ <literal>joe</literal>:
+<programlisting>
+ALTER VARIABLE boo OWNER TO joe;
+</programlisting>
+ </para>
+
+ <para>
+ To change the schema of the session variable <literal>boo</literal> to
+ <literal>private</literal>:
+<programlisting>
+ALTER VARIABLE boo SET SCHEMA private;
+</programlisting>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ Session variables and this command in particular are a PostgreSQL extension.
+ </para>
+ </refsect1>
+
+ <refsect1 id="sql-altervariable-see-also">
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index 5b43c56b133..21cd80818fb 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -65,6 +65,7 @@ COMMENT ON
TRANSFORM FOR <replaceable>type_name</replaceable> LANGUAGE <replaceable>lang_name</replaceable> |
TRIGGER <replaceable class="parameter">trigger_name</replaceable> ON <replaceable class="parameter">table_name</replaceable> |
TYPE <replaceable class="parameter">object_name</replaceable> |
+ VARIABLE <replaceable class="parameter">object_name</replaceable> |
VIEW <replaceable class="parameter">object_name</replaceable>
} IS { <replaceable class="parameter">string_literal</replaceable> | NULL }
diff --git a/doc/src/sgml/ref/create_schema.sgml b/doc/src/sgml/ref/create_schema.sgml
index ed69298ccc6..d2bb265209b 100644
--- a/doc/src/sgml/ref/create_schema.sgml
+++ b/doc/src/sgml/ref/create_schema.sgml
@@ -103,9 +103,10 @@ CREATE SCHEMA IF NOT EXISTS AUTHORIZATION <replaceable class="parameter">role_sp
schema. Currently, only <command>CREATE
TABLE</command>, <command>CREATE VIEW</command>, <command>CREATE
INDEX</command>, <command>CREATE SEQUENCE</command>, <command>CREATE
- TRIGGER</command> and <command>GRANT</command> are accepted as clauses
- within <command>CREATE SCHEMA</command>. Other kinds of objects may
- be created in separate commands after the schema is created.
+ TRIGGER</command>, <command>GRANT</command> and <command>CREATE
+ VARIABLE</command> are accepted as clauses within <command>CREATE
+ SCHEMA</command>. Other kinds of objects may be created in separate
+ commands after the schema is created.
</para>
</listitem>
</varlistentry>
@@ -214,6 +215,11 @@ CREATE VIEW hollywood.winners AS
The <literal>IF NOT EXISTS</literal> option is a
<productname>PostgreSQL</productname> extension.
</para>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
</refsect1>
<refsect1>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
new file mode 100644
index 00000000000..6e988f2e472
--- /dev/null
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -0,0 +1,149 @@
+<!--
+doc/src/sgml/ref/create_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-createvariable">
+ <indexterm zone="sql-createvariable">
+ <primary>CREATE VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>defining</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>CREATE VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>CREATE VARIABLE</refname>
+ <refpurpose>define a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+</synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command creates a session variable.
+ Session variables, like relations, exist within a schema and their access is
+ controlled via the commands <command>GRANT</command> and <command>REVOKE</command>.
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a session variable's value returns NULL, unless its value is set to
+ something else in the current session with a <command>LET</command> command.
+ The content of a session variable is not transactional. This is the same as
+ regular variables in procedural languages.
+ </para>
+
+ <para>
+ Session variables are retrieved by the <command>SELECT</command>
+ command. Their value is set with the <command>LET</command> command.
+ </para>
+
+ <note>
+ <para>
+ Session variables can be <quote>shadowed</quote> by other identifiers.
+ For details, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </note>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+
+ <varlistentry id="sql-createvariable-if-not-exists">
+ <term><literal>IF NOT EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the name already exists. A notice is issued in
+ this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-name">
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-data_type">
+ <term><replaceable class="parameter">data_type</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the data type of the session
+ variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-collate">
+ <term><literal>COLLATE <replaceable>collation</replaceable></literal></term>
+ <listitem>
+ <para>
+ The <literal>COLLATE</literal> clause assigns a collation to the session
+ variable (which must be of a collatable data type). If not specified,
+ the data type's default collation is used.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para>
+ Use the <command>DROP VARIABLE</command> command to remove a session
+ variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ Create an date session variable <literal>var1</literal>:
+<programlisting>
+CREATE VARIABLE var1 AS date;
+</programlisting>
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
new file mode 100644
index 00000000000..5bdb3560f0b
--- /dev/null
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -0,0 +1,117 @@
+<!--
+doc/src/sgml/ref/drop_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-dropvariable">
+ <indexterm zone="sql-dropvariable">
+ <primary>DROP VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>removing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>DROP VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>DROP VARIABLE</refname>
+ <refpurpose>remove a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+DROP VARIABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ <command>DROP VARIABLE</command> removes a session variable.
+ A session variable can only be removed by its owner or a superuser.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>IF EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the session variable does not exist. A notice is
+ issued in this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of a session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>CASCADE</literal></term>
+ <listitem>
+ <para>
+ Automatically drop objects that depend on the session variable (such as
+ views), and in turn all objects that depend on those objects
+ (see <xref linkend="ddl-depend"/>).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RESTRICT</literal></term>
+ <listitem>
+ <para>
+ Refuse to drop the session variable if any objects depend on it. This is
+ the default.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To remove the session variable <literal>var1</literal>:
+
+<programlisting>
+DROP VARIABLE var1;
+</programlisting></para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>DROP VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index 999f657d5c0..c11860fa200 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -101,6 +101,12 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
[ WITH { ADMIN | INHERIT | SET } { OPTION | TRUE | FALSE } ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+GRANT { SELECT | UPDATE | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
@@ -119,8 +125,8 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
that grants privileges on a database object (table, column, view,
foreign table, sequence, database, foreign-data wrapper, foreign server,
function, procedure, procedural language, large object, configuration
- parameter, schema, tablespace, or type), and one that grants
- membership in a role. These variants are similar in many ways, but
+ parameter, schema, session variable, tablespace, or type), and one that
+ grants membership in a role. These variants are similar in many ways, but
they are different enough to be described separately.
</para>
@@ -236,9 +242,9 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
<para>
There is also an option to grant privileges on all objects of the same
type within one or more schemas. This functionality is currently supported
- only for tables, sequences, functions, and procedures. <literal>ALL
- TABLES</literal> also affects views and foreign tables, just like the
- specific-object <command>GRANT</command> command. <literal>ALL
+ only for tables, sequences, functions, procedures and variables.
+ <literal>ALL TABLES</literal> also affects views and foreign tables, just
+ like the specific-object <command>GRANT</command> command. <literal>ALL
FUNCTIONS</literal> also affects aggregate and window functions, but not
procedures, again just like the specific-object <command>GRANT</command>
command. Use <literal>ALL ROUTINES</literal> to include procedures.
@@ -518,8 +524,8 @@ GRANT admins TO joe;
</para>
<para>
- Privileges on databases, tablespaces, schemas, languages, and
- configuration parameters are
+ Privileges on databases, tablespaces, schemas, languages, session variables
+ and configuration parameters are
<productname>PostgreSQL</productname> extensions.
</para>
</refsect1>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index f3044fac1fa..da9ef01ddea 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -2134,6 +2134,19 @@ SELECT $1 \parse stmt1
</listitem>
</varlistentry>
+ <varlistentry id="app-psql-meta-command-dv">
+ <term><literal>\dV[+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
+ <listitem>
+ <para>
+ Lists session variables.
+ If <replaceable class="parameter">pattern</replaceable> is
+ specified, only session variables whose names match the pattern are listed.
+ If the form <literal>\dV+</literal> is used, additional information
+ about each variable is shown, like access privileges and description.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="app-psql-meta-command-du">
<term><literal>\du[Sx+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
<listitem>
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index 8df492281a1..760fddb7c20 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -130,6 +130,14 @@ REVOKE [ { ADMIN | INHERIT | SET } OPTION FOR ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
[ CASCADE | RESTRICT ]
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ FROM { <replaceable class="parameter">role_specification</replaceable> | PUBLIC } [, ...]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+ [ CASCADE | RESTRICT ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index ff85ace83fc..25578f3946c 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -75,6 +75,7 @@
&alterType;
&alterUser;
&alterUserMapping;
+ &alterVariable;
&alterView;
&analyze;
&begin;
@@ -127,6 +128,7 @@
&createType;
&createUser;
&createUserMapping;
+ &createVariable;
&createView;
&deallocate;
&declare;
@@ -175,6 +177,7 @@
&dropType;
&dropUser;
&dropUserMapping;
+ &dropVariable;
&dropView;
&end;
&execute;
diff --git a/src/backend/catalog/Makefile b/src/backend/catalog/Makefile
index c090094ed08..2c20d60db19 100644
--- a/src/backend/catalog/Makefile
+++ b/src/backend/catalog/Makefile
@@ -45,6 +45,7 @@ OBJS = \
pg_shdepend.o \
pg_subscription.o \
pg_type.o \
+ pg_variable.o \
storage.o \
toasting.o
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 02a754cc30a..1e8ce752b90 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -64,6 +64,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -291,6 +292,9 @@ restrict_and_check_grant(bool is_grant, AclMode avail_goptions, bool all_privs,
case OBJECT_PARAMETER_ACL:
whole_mask = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ whole_mask = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", objtype);
/* not reached, but keep compiler quiet */
@@ -535,6 +539,10 @@ ExecuteGrantStmt(GrantStmt *stmt)
all_privileges = ACL_ALL_RIGHTS_PARAMETER_ACL;
errormsg = gettext_noop("invalid privilege type %s for parameter");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) stmt->objtype);
@@ -640,6 +648,9 @@ ExecGrantStmt_oids(InternalGrant *istmt)
case OBJECT_PARAMETER_ACL:
ExecGrant_Parameter(istmt);
break;
+ case OBJECT_VARIABLE:
+ ExecGrant_common(istmt, VariableRelationId, ACL_ALL_RIGHTS_VARIABLE, NULL);
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) istmt->objtype);
@@ -760,6 +771,18 @@ objectNamesToOids(ObjectType objtype, List *objnames, bool is_grant)
objects = lappend_oid(objects, parameterId);
}
break;
+
+ case OBJECT_VARIABLE:
+ foreach_node(RangeVar, varvar, objnames)
+ {
+ Oid relOid;
+
+ relOid = LookupVariable(varvar->schemaname,
+ varvar->relname,
+ false);
+ objects = lappend_oid(objects, relOid);
+ }
+ break;
}
return objects;
@@ -846,6 +869,32 @@ objectsInSchemaToOids(ObjectType objtype, List *nspnames)
table_close(rel, AccessShareLock);
}
break;
+ case OBJECT_VARIABLE:
+ {
+ ScanKeyData key;
+ Relation rel;
+ TableScanDesc scan;
+ HeapTuple tuple;
+
+ ScanKeyInit(&key,
+ Anum_pg_variable_varnamespace,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(namespaceId));
+
+ rel = table_open(VariableRelationId, AccessShareLock);
+ scan = table_beginscan_catalog(rel, 1, &key);
+
+ while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+ {
+ Oid oid = ((Form_pg_proc) GETSTRUCT(tuple))->oid;
+
+ objects = lappend_oid(objects, oid);
+ }
+
+ table_endscan(scan);
+ table_close(rel, AccessShareLock);
+ }
+ break;
default:
/* should not happen */
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
@@ -1005,6 +1054,10 @@ ExecAlterDefaultPrivilegesStmt(ParseState *pstate, AlterDefaultPrivilegesStmt *s
all_privileges = ACL_ALL_RIGHTS_SCHEMA;
errormsg = gettext_noop("invalid privilege type %s for schema");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) action->objtype);
@@ -1196,6 +1249,12 @@ SetDefaultACL(InternalDefaultACL *iacls)
this_privileges = ACL_ALL_RIGHTS_SCHEMA;
break;
+ case OBJECT_VARIABLE:
+ objtype = DEFACLOBJ_VARIABLE;
+ if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
+ this_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ break;
+
default:
elog(ERROR, "unrecognized object type: %d",
(int) iacls->objtype);
@@ -1439,6 +1498,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case DEFACLOBJ_NAMESPACE:
iacls.objtype = OBJECT_SCHEMA;
break;
+ case DEFACLOBJ_VARIABLE:
+ iacls.objtype = OBJECT_VARIABLE;
+ break;
default:
/* Shouldn't get here */
elog(ERROR, "unexpected default ACL type: %d",
@@ -1499,6 +1561,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case ParameterAclRelationId:
istmt.objtype = OBJECT_PARAMETER_ACL;
break;
+ case VariableRelationId:
+ istmt.objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unexpected object class %u", classid);
break;
@@ -2732,6 +2797,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("permission denied for type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("permission denied for session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("permission denied for view %s");
break;
@@ -2843,6 +2911,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("must be owner of type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("must be owner of session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("must be owner of view %s");
break;
@@ -2991,6 +3062,8 @@ pg_aclmask(ObjectType objtype, Oid object_oid, AttrNumber attnum, Oid roleid,
return ACL_NO_RIGHTS;
case OBJECT_TYPE:
return object_aclmask(TypeRelationId, object_oid, roleid, mask, how);
+ case OBJECT_VARIABLE:
+ return object_aclmask(VariableRelationId, object_oid, roleid, mask, how);
default:
elog(ERROR, "unrecognized object type: %d",
(int) objtype);
@@ -4250,6 +4323,10 @@ get_user_default_acl(ObjectType objtype, Oid ownerId, Oid nsp_oid)
defaclobjtype = DEFACLOBJ_NAMESPACE;
break;
+ case OBJECT_VARIABLE:
+ defaclobjtype = DEFACLOBJ_VARIABLE;
+ break;
+
default:
return NULL;
}
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 18316a3968b..9e0f648b74f 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -65,12 +65,14 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/comment.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "commands/extension.h"
#include "commands/policy.h"
#include "commands/publicationcmds.h"
+#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
#include "commands/trigger.h"
@@ -1444,6 +1446,10 @@ doDeletion(const ObjectAddress *object, int flags)
RemovePublicationById(object->objectId);
break;
+ case VariableRelationId:
+ DropVariableById(object->objectId);
+ break;
+
case CastRelationId:
case CollationRelationId:
case ConversionRelationId:
diff --git a/src/backend/catalog/meson.build b/src/backend/catalog/meson.build
index 1958ea9238a..ed44c877fca 100644
--- a/src/backend/catalog/meson.build
+++ b/src/backend/catalog/meson.build
@@ -32,6 +32,7 @@ backend_sources += files(
'pg_shdepend.c',
'pg_subscription.c',
'pg_type.c',
+ 'pg_variable.c',
'storage.c',
'toasting.c',
)
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index d97d632a7ef..4307cad15c7 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "common/hashfn_unstable.h"
#include "funcapi.h"
@@ -225,6 +226,7 @@ static bool TSParserIsVisibleExt(Oid prsId, bool *is_missing);
static bool TSDictionaryIsVisibleExt(Oid dictId, bool *is_missing);
static bool TSTemplateIsVisibleExt(Oid tmplId, bool *is_missing);
static bool TSConfigIsVisibleExt(Oid cfgid, bool *is_missing);
+static bool VariableIsVisibleExt(Oid varid, bool *is_missing);
static void recomputeNamespacePath(void);
static void AccessTempTableNamespace(bool force);
static void InitTempTableNamespace(void);
@@ -986,6 +988,84 @@ RelationIsVisibleExt(Oid relid, bool *is_missing)
return visible;
}
+/*
+ * VariableIsVisible
+ * Determine whether a variable (identified by OID) is visible in the
+ * current search path. Visible means "would be found by searching
+ * for the unqualified variable name".
+ */
+bool
+VariableIsVisible(Oid varid)
+{
+ return VariableIsVisibleExt(varid, NULL);
+}
+
+/*
+ * VariableIsVisibleExt
+ * As above, but if the variable isn't found and is_missing is not NULL,
+ * then set *is_missing = true and return false, instead of throwing
+ * an error. (Caller must initialize *is_missing = false.)
+ */
+static bool
+VariableIsVisibleExt(Oid varid, bool *is_missing)
+{
+ HeapTuple vartup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+ bool visible;
+
+ vartup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+ if (!HeapTupleIsValid(vartup))
+ {
+ if (is_missing != NULL)
+ {
+ *is_missing = true;
+ return false;
+ }
+
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+ }
+ varform = (Form_pg_variable) GETSTRUCT(vartup);
+
+ recomputeNamespacePath();
+
+ /*
+ * Quick check: if it ain't in the path at all, it ain't visible. We
+ * don't expect usage of session variables in the system namespace.
+ */
+ varnamespace = varform->varnamespace;
+ if (!list_member_oid(activeSearchPath, varnamespace))
+ visible = false;
+ else
+ {
+ /*
+ * If it is in the path, it might still not be visible; it could be
+ * hidden by another variable of the same name earlier in the path. So
+ * we must do a slow check for conflicting relations.
+ */
+ char *varname = NameStr(varform->varname);
+
+ visible = false;
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ if (namespaceId == varnamespace)
+ {
+ /* found it first in path */
+ visible = true;
+ break;
+ }
+ if (OidIsValid(get_varname_varid(varname, namespaceId)))
+ {
+ /* found something else first in path */
+ break;
+ }
+ }
+ }
+
+ ReleaseSysCache(vartup);
+
+ return visible;
+}
/*
* TypenameGetTypid
@@ -3289,6 +3369,133 @@ TSConfigIsVisibleExt(Oid cfgid, bool *is_missing)
return visible;
}
+/*
+ * Returns oid of session variable specified by possibly qualified identifier.
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariable(const char *nspname,
+ const char *varname,
+ bool missing_ok)
+{
+ Oid varoid = InvalidOid;
+
+ if (nspname)
+ {
+ Oid namespaceId = LookupExplicitNamespace(nspname, missing_ok);
+
+ /* if nspname is a known namespace, the variable must be there */
+ if (OidIsValid(namespaceId))
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+ }
+ }
+ else
+ {
+ /* iterate over the schemas on the search_path */
+ recomputeNamespacePath();
+
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+
+ if (OidIsValid(varoid))
+ break;
+ }
+ }
+
+ if (!OidIsValid(varoid) && !missing_ok)
+ {
+ if (nspname)
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s.%s\" does not exist",
+ nspname, varname)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" does not exist",
+ varname)));
+ }
+
+ return varoid;
+}
+
+/*
+ * Returns oid of session variable specified by possibly qualified identifier
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariableFromNameList(List *names,
+ bool missing_ok)
+{
+ char *catname = NULL;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ switch (list_length(names))
+ {
+ case 1:
+ varname = strVal(linitial(names));
+ break;
+ case 2:
+ nspname = strVal(linitial(names));
+ varname = strVal(lsecond(names));
+ break;
+ case 3:
+ catname = strVal(linitial(names));
+ nspname = strVal(lsecond(names));
+ varname = strVal(lthird(names));
+
+ /* check catalog name */
+ if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ break;
+ default:
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper session variable name (too many dotted names): %s",
+ NameListToString(names))));
+ break;
+ }
+
+ return LookupVariable(nspname, varname, missing_ok);
+}
+
+/*
+ * The input list contains names with indirection expressions used as the left
+ * part of LET statement. The following routine returns a new list with only
+ * initial strings (names) - without indirection expressions.
+ */
+List *
+NamesFromList(List *names)
+{
+ ListCell *l;
+ List *result = NIL;
+
+ foreach(l, names)
+ {
+ Node *n = lfirst(l);
+
+ if (IsA(n, String))
+ {
+ result = lappend(result, n);
+ }
+ else
+ break;
+ }
+
+ return result;
+}
/*
* DeconstructQualifiedName
@@ -5085,3 +5292,17 @@ pg_is_other_temp_schema(PG_FUNCTION_ARGS)
PG_RETURN_BOOL(isOtherTempNamespace(oid));
}
+
+Datum
+pg_variable_is_visible(PG_FUNCTION_ARGS)
+{
+ Oid oid = PG_GETARG_OID(0);
+ bool result;
+ bool is_missing = false;
+
+ result = VariableIsVisibleExt(oid, &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+ PG_RETURN_BOOL(result);
+}
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index d8eb8d3deaa..4a464dfea7e 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -62,6 +62,7 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -636,6 +637,20 @@ static const ObjectPropertyType ObjectProperty[] =
OBJECT_USER_MAPPING,
false
},
+ {
+ "session variable",
+ VariableRelationId,
+ VariableOidIndexId,
+ VARIABLEOID,
+ VARIABLENAMENSP,
+ Anum_pg_variable_oid,
+ Anum_pg_variable_varname,
+ Anum_pg_variable_varnamespace,
+ Anum_pg_variable_varowner,
+ Anum_pg_variable_varacl,
+ OBJECT_VARIABLE,
+ true
+ }
};
/*
@@ -831,6 +846,9 @@ static const struct object_type_map
},
{
"statistics object", OBJECT_STATISTIC_EXT
+ },
+ {
+ "session variable", OBJECT_VARIABLE
}
};
@@ -856,6 +874,7 @@ static ObjectAddress get_object_address_attrdef(ObjectType objtype,
bool missing_ok);
static ObjectAddress get_object_address_type(ObjectType objtype,
TypeName *typename, bool missing_ok);
+static ObjectAddress get_object_address_variable(List *object, bool missing_ok);
static ObjectAddress get_object_address_opcf(ObjectType objtype, List *object,
bool missing_ok);
static ObjectAddress get_object_address_opf_member(ObjectType objtype,
@@ -1127,6 +1146,9 @@ get_object_address(ObjectType objtype, Node *object,
missing_ok);
address.objectSubId = 0;
break;
+ case OBJECT_VARIABLE:
+ address = get_object_address_variable(castNode(List, object), missing_ok);
+ break;
/* no default, to let compiler warn about missing case */
}
@@ -2005,16 +2027,20 @@ get_object_address_defacl(List *object, bool missing_ok)
case DEFACLOBJ_NAMESPACE:
objtype_str = "schemas";
break;
+ case DEFACLOBJ_VARIABLE:
+ objtype_str = "variables";
+ break;
default:
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized default ACL object type \"%c\"", objtype),
- errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
+ errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
DEFACLOBJ_RELATION,
DEFACLOBJ_SEQUENCE,
DEFACLOBJ_FUNCTION,
DEFACLOBJ_TYPE,
- DEFACLOBJ_NAMESPACE)));
+ DEFACLOBJ_NAMESPACE,
+ DEFACLOBJ_VARIABLE)));
}
/*
@@ -2098,6 +2124,24 @@ textarray_to_strvaluelist(ArrayType *arr)
return list;
}
+/*
+ * Find the ObjectAddress for a session variable
+ */
+static ObjectAddress
+get_object_address_variable(List *object, bool missing_ok)
+{
+ ObjectAddress address;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ ObjectAddressSet(address, VariableRelationId, InvalidOid);
+
+ DeconstructQualifiedName(object, &nspname, &varname);
+ address.objectId = LookupVariable(nspname, varname, missing_ok);
+
+ return address;
+}
+
/*
* SQL-callable version of get_object_address
*/
@@ -2292,6 +2336,7 @@ pg_get_object_address(PG_FUNCTION_ARGS)
case OBJECT_TABCONSTRAINT:
case OBJECT_OPCLASS:
case OBJECT_OPFAMILY:
+ case OBJECT_VARIABLE:
objnode = (Node *) name;
break;
case OBJECT_ACCESS_METHOD:
@@ -2463,6 +2508,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
case OBJECT_STATISTIC_EXT:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
if (!object_ownercheck(address.classId, address.objectId, roleid))
aclcheck_error(ACLCHECK_NOT_OWNER, objtype,
NameListToString(castNode(List, object)));
@@ -3492,6 +3538,32 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
break;
}
+ case VariableRelationId:
+ {
+ char *nspname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ if (VariableIsVisible(object->objectId))
+ nspname = NULL;
+ else
+ nspname = get_namespace_name(varform->varnamespace);
+
+ appendStringInfo(&buffer, _("session variable %s"),
+ quote_qualified_identifier(nspname,
+ NameStr(varform->varname)));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
case TSParserRelationId:
{
HeapTuple tup;
@@ -3844,6 +3916,16 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
_("default privileges on new schemas belonging to role %s"),
rolename);
break;
+ case DEFACLOBJ_VARIABLE:
+ if (nspname)
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s in schema %s"),
+ rolename, nspname);
+ else
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s"),
+ rolename);
+ break;
default:
/* shouldn't get here */
if (nspname)
@@ -4660,6 +4742,10 @@ getObjectTypeDescription(const ObjectAddress *object, bool missing_ok)
appendStringInfoString(&buffer, "transform");
break;
+ case VariableRelationId:
+ appendStringInfoString(&buffer, "session variable");
+ break;
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
@@ -5766,6 +5852,10 @@ getObjectIdentityParts(const ObjectAddress *object,
appendStringInfoString(&buffer,
" on schemas");
break;
+ case DEFACLOBJ_VARIABLE:
+ appendStringInfoString(&buffer,
+ " on session variables");
+ break;
}
if (objname)
@@ -6006,6 +6096,33 @@ getObjectIdentityParts(const ObjectAddress *object,
}
break;
+ case VariableRelationId:
+ {
+ char *schema;
+ char *varname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ schema = get_namespace_name_or_temp(varform->varnamespace);
+ varname = NameStr(varform->varname);
+
+ appendStringInfo(&buffer, "%s",
+ quote_qualified_identifier(schema, varname));
+
+ if (objname)
+ *objname = list_make2(schema, pstrdup(varname));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
diff --git a/src/backend/catalog/pg_shdepend.c b/src/backend/catalog/pg_shdepend.c
index 536191284e8..c6fd1fa074f 100644
--- a/src/backend/catalog/pg_shdepend.c
+++ b/src/backend/catalog/pg_shdepend.c
@@ -46,6 +46,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
@@ -1714,6 +1715,7 @@ shdepReassignOwned_Owner(Form_pg_shdepend sdepForm, Oid newrole)
case DatabaseRelationId:
case TSConfigRelationId:
case TSDictionaryRelationId:
+ case VariableRelationId:
AlterObjectOwner_internal(sdepForm->classid,
sdepForm->objid,
newrole);
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
new file mode 100644
index 00000000000..29d967a2d5b
--- /dev/null
+++ b/src/backend/catalog/pg_variable.c
@@ -0,0 +1,251 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.c
+ * session variables
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/catalog/pg_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "catalog/dependency.h"
+#include "catalog/indexing.h"
+#include "catalog/namespace.h"
+#include "catalog/objectaccess.h"
+#include "catalog/pg_collation.h"
+#include "catalog/pg_namespace.h"
+#include "catalog/pg_variable.h"
+#include "miscadmin.h"
+#include "parser/parse_type.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+static ObjectAddress create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists);
+
+
+/*
+ * Creates entry in pg_variable table
+ */
+static ObjectAddress
+create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists)
+{
+ Acl *varacl;
+ NameData varname;
+ bool nulls[Natts_pg_variable];
+ Datum values[Natts_pg_variable];
+ Relation rel;
+ HeapTuple tup;
+ TupleDesc tupdesc;
+ ObjectAddress myself,
+ referenced;
+ ObjectAddresses *addrs;
+ Oid varid;
+
+ Assert(varName);
+ Assert(OidIsValid(varNamespace));
+ Assert(OidIsValid(varType));
+ Assert(OidIsValid(varOwner));
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ /*
+ * Check for duplicates. Note that this does not really prevent
+ * duplicates, it's here just to provide nicer error message in common
+ * case. The real protection is the unique key on the catalog.
+ */
+ if (SearchSysCacheExists2(VARIABLENAMENSP,
+ PointerGetDatum(varName),
+ ObjectIdGetDatum(varNamespace)))
+ {
+ if (if_not_exists)
+ ereport(NOTICE,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists, skipping",
+ varName)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists",
+ varName)));
+
+ table_close(rel, RowExclusiveLock);
+
+ return InvalidObjectAddress;
+ }
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, false, sizeof(nulls));
+
+ namestrcpy(&varname, varName);
+
+ varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
+
+ values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
+ values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
+ values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
+ values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
+ values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
+ values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+
+ varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
+ varNamespace);
+ if (varacl != NULL)
+ values[Anum_pg_variable_varacl - 1] = PointerGetDatum(varacl);
+ else
+ nulls[Anum_pg_variable_varacl - 1] = true;
+
+ tupdesc = RelationGetDescr(rel);
+
+ tup = heap_form_tuple(tupdesc, values, nulls);
+ CatalogTupleInsert(rel, tup);
+ Assert(OidIsValid(varid));
+
+ addrs = new_object_addresses();
+
+ ObjectAddressSet(myself, VariableRelationId, varid);
+
+ /* dependency on namespace */
+ ObjectAddressSet(referenced, NamespaceRelationId, varNamespace);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on used type */
+ ObjectAddressSet(referenced, TypeRelationId, varType);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on collation */
+ if (OidIsValid(varCollation) &&
+ varCollation != DEFAULT_COLLATION_OID)
+ {
+ ObjectAddressSet(referenced, CollationRelationId, varCollation);
+ add_exact_object_address(&referenced, addrs);
+ }
+
+ record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
+ free_object_addresses(addrs);
+
+ /* dependency on owner */
+ recordDependencyOnOwner(VariableRelationId, varid, varOwner);
+
+ /* dependencies on roles mentioned in default ACL */
+ recordDependencyOnNewAcl(VariableRelationId, varid, 0, varOwner, varacl);
+
+ /* dependency on extension */
+ recordDependencyOnCurrentExtension(&myself, false);
+
+ heap_freetuple(tup);
+
+ /* post creation hook for new function */
+ InvokeObjectPostCreateHook(VariableRelationId, varid, 0);
+
+ table_close(rel, RowExclusiveLock);
+
+ return myself;
+}
+
+/*
+ * Creates a new variable
+ *
+ * Used by CREATE VARIABLE command
+ */
+ObjectAddress
+CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
+{
+ Oid namespaceid;
+ AclResult aclresult;
+ Oid typid;
+ int32 typmod;
+ Oid varowner = GetUserId();
+ Oid collation;
+ Oid typcollation;
+ ObjectAddress variable;
+
+ namespaceid =
+ RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL);
+
+ typenameTypeIdAndMod(pstate, stmt->typeName, &typid, &typmod);
+
+ /* disallow pseudotypes */
+ if (get_typtype(typid) == TYPTYPE_PSEUDO)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("session variable cannot be pseudo-type %s",
+ format_type_be(typid))));
+
+ aclresult = object_aclcheck(TypeRelationId, typid, GetUserId(), ACL_USAGE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error_type(aclresult, typid);
+
+ typcollation = get_typcollation(typid);
+
+ if (stmt->collClause)
+ collation = LookupCollation(pstate,
+ stmt->collClause->collname,
+ stmt->collClause->location);
+ else
+ collation = typcollation;
+
+ /* complain if COLLATE is applied to an uncollatable type */
+ if (OidIsValid(collation) && !OidIsValid(typcollation))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("collations are not supported by type %s",
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->collClause->location)));
+
+ variable = create_variable(stmt->variable->relname,
+ namespaceid,
+ typid,
+ typmod,
+ varowner,
+ collation,
+ stmt->if_not_exists);
+
+ elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
+ stmt->variable->relname, variable.objectId);
+
+ return variable;
+}
+
+/*
+ * Drop variable by OID
+ */
+void
+DropVariableById(Oid varid)
+{
+ Relation rel;
+ HeapTuple tup;
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ CatalogTupleDelete(rel, &tup->t_self);
+
+ ReleaseSysCache(tup);
+
+ table_close(rel, RowExclusiveLock);
+}
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 78c1d4e1b84..67153cd8b94 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/collationcmds.h"
#include "commands/dbcommands.h"
@@ -140,6 +141,10 @@ report_namespace_conflict(Oid classId, const char *name, Oid nspOid)
Assert(OidIsValid(nspOid));
msgfmt = gettext_noop("text search configuration \"%s\" already exists in schema \"%s\"");
break;
+ case VariableRelationId:
+ Assert(OidIsValid(nspOid));
+ msgfmt = gettext_noop("session variable \"%s\" already exists in schema \"%s\"");
+ break;
default:
elog(ERROR, "unsupported object class: %u", classId);
break;
@@ -419,6 +424,7 @@ ExecRenameStmt(RenameStmt *stmt)
case OBJECT_TSTEMPLATE:
case OBJECT_PUBLICATION:
case OBJECT_SUBSCRIPTION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
Relation catalog;
@@ -559,6 +565,7 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt,
case OBJECT_TSDICTIONARY:
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
+ case OBJECT_VARIABLE:
{
Relation catalog;
Oid classId;
@@ -641,6 +648,7 @@ AlterObjectNamespace_oid(Oid classId, Oid objid, Oid nspOid,
case TSDictionaryRelationId:
case TSTemplateRelationId:
case TSConfigRelationId:
+ case VariableRelationId:
{
Relation catalog;
@@ -871,6 +879,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
case OBJECT_TABLESPACE:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
diff --git a/src/backend/commands/dropcmds.c b/src/backend/commands/dropcmds.c
index ceb9a229b63..ebb585dc4a1 100644
--- a/src/backend/commands/dropcmds.c
+++ b/src/backend/commands/dropcmds.c
@@ -476,6 +476,10 @@ does_not_exist_skipping(ObjectType objtype, Node *object)
msg = gettext_noop("publication \"%s\" does not exist, skipping");
name = strVal(object);
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("session variable \"%s\" does not exist, skipping");
+ name = NameListToString(castNode(List, object));
+ break;
case OBJECT_COLUMN:
case OBJECT_DATABASE:
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index edc2c988e29..1839c1f82c5 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -2149,6 +2149,8 @@ stringify_grant_objtype(ObjectType objtype)
return "TABLESPACE";
case OBJECT_TYPE:
return "TYPE";
+ case OBJECT_VARIABLE:
+ return "VARIABLE";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
@@ -2232,6 +2234,8 @@ stringify_adefprivs_objtype(ObjectType objtype)
return "TABLESPACES";
case OBJECT_TYPE:
return "TYPES";
+ case OBJECT_VARIABLE:
+ return "VARIABLES";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
diff --git a/src/backend/commands/seclabel.c b/src/backend/commands/seclabel.c
index cee5d7bbb9c..57b4e6719c2 100644
--- a/src/backend/commands/seclabel.c
+++ b/src/backend/commands/seclabel.c
@@ -92,6 +92,7 @@ SecLabelSupportsObjectType(ObjectType objtype)
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
case OBJECT_USER_MAPPING:
+ case OBJECT_VARIABLE:
return false;
/*
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 72a1b64c2a2..6fd22c5ce5a 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -52,6 +52,7 @@
#include "catalog/pg_tablespace.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "catalog/storage.h"
#include "catalog/storage_xlog.h"
#include "catalog/toasting.h"
@@ -6823,6 +6824,7 @@ ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
* (possibly nested several levels deep in composite types, arrays, etc!).
* Eventually, we'd like to propagate the check or rewrite operation
* into such tables, but for now, just error out if we find any.
+ * Also, check if "typeOid" is used as type of some session variable.
*
* Caller should provide either the associated relation of a rowtype,
* or a type name (not both) for use in the error message, if any.
@@ -6886,6 +6888,45 @@ find_composite_type_dependencies(Oid typeOid, Relation origRelation,
continue;
}
+ /* check if the type is used as type of some session variable */
+ if (pg_depend->classid == VariableRelationId)
+ {
+ Oid varid = pg_depend->objid;
+
+ if (origTypeName)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ origTypeName,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter foreign table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_RELATION ||
+ origRelation->rd_rel->relkind == RELKIND_MATVIEW ||
+ origRelation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+
+ continue;
+ }
+
/* Else, ignore dependees that aren't relations */
if (pg_depend->classid != RelationRelationId)
continue;
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 3cb3ca1cca1..473d98ff062 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -53,6 +53,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_range.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablecmds.h"
#include "commands/typecmds.h"
@@ -3369,6 +3370,20 @@ get_rels_with_domain(Oid domainOid, LOCKMODE lockmode)
}
continue;
}
+ else if (pg_depend->classid == VariableRelationId)
+ {
+ /*
+ * We cannot to validate constraint inside session variables
+ * from other sessions, so better to fail if there are any
+ * session variable, that use this domain.
+ */
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter domain \"%s\" because session variable \"%s.%s\" uses it",
+ domainTypeName,
+ get_namespace_name(get_session_variable_namespace(pg_depend->objid)),
+ get_session_variable_name(pg_depend->objid))));
+ }
/* Else, ignore dependees that aren't user columns of relations */
/* (we assume system columns are never of domain types) */
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index d3887628d46..2de2022b281 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -52,6 +52,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_am.h"
#include "catalog/pg_trigger.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/trigger.h"
#include "gramparse.h"
@@ -285,8 +286,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
ConstraintsSetStmt CopyStmt CreateAsStmt CreateCastStmt
CreateDomainStmt CreateExtensionStmt CreateGroupStmt CreateOpClassStmt
CreateOpFamilyStmt AlterOpFamilyStmt CreatePLangStmt
- CreateSchemaStmt CreateSeqStmt CreateStmt CreateStatsStmt CreateTableSpaceStmt
- CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
+ CreateSchemaStmt CreateSeqStmt CreateSessionVarStmt CreateStmt CreateStatsStmt
+ CreateTableSpaceStmt CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
CreateAssertionStmt CreateTransformStmt CreateTrigStmt CreateEventTrigStmt
CreateUserStmt CreateUserMappingStmt CreateRoleStmt CreatePolicyStmt
CreatedbStmt DeclareCursorStmt DefineStmt DeleteStmt DiscardStmt DoStmt
@@ -783,8 +784,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
UESCAPE UNBOUNDED UNCONDITIONAL UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN
UNLISTEN UNLOGGED UNTIL UPDATE USER USING
- VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
- VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
+ VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARIABLE
+ VARIABLES VARYING VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
@@ -1050,6 +1051,7 @@ stmt:
| CreatePolicyStmt
| CreatePLangStmt
| CreateSchemaStmt
+ | CreateSessionVarStmt
| CreateSeqStmt
| CreateStmt
| CreateSubscriptionStmt
@@ -1592,6 +1594,7 @@ schema_stmt:
| CreateTrigStmt
| GrantStmt
| ViewStmt
+ | CreateSessionVarStmt
;
@@ -5245,6 +5248,34 @@ create_extension_opt_item:
}
;
+/*****************************************************************************
+ *
+ * QUERY :
+ * CREATE VARIABLE varname [AS] type
+ *
+ *****************************************************************************/
+
+CreateSessionVarStmt:
+ CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $3;
+ n->typeName = $5;
+ n->collClause = (CollateClause *) $6;
+ n->if_not_exists = false;
+ $$ = (Node *) n;
+ }
+ | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $6;
+ n->typeName = $8;
+ n->collClause = (CollateClause *) $9;
+ n->if_not_exists = true;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
@@ -7036,6 +7067,7 @@ object_type_any_name:
| TEXT_P SEARCH DICTIONARY { $$ = OBJECT_TSDICTIONARY; }
| TEXT_P SEARCH TEMPLATE { $$ = OBJECT_TSTEMPLATE; }
| TEXT_P SEARCH CONFIGURATION { $$ = OBJECT_TSCONFIGURATION; }
+ | VARIABLE { $$ = OBJECT_VARIABLE; }
;
/*
@@ -7912,6 +7944,14 @@ privilege_target:
n->objs = $2;
$$ = n;
}
+ | VARIABLE qualified_name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_OBJECT;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $2;
+ $$ = n;
+ }
| ALL TABLES IN_P SCHEMA name_list
{
PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
@@ -7957,6 +7997,14 @@ privilege_target:
n->objs = $5;
$$ = n;
}
+ | ALL VARIABLES IN_P SCHEMA name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_ALL_IN_SCHEMA;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $5;
+ $$ = n;
+ }
;
@@ -8154,6 +8202,7 @@ defacl_privilege_target:
| SEQUENCES { $$ = OBJECT_SEQUENCE; }
| TYPES_P { $$ = OBJECT_TYPE; }
| SCHEMAS { $$ = OBJECT_SCHEMA; }
+ | VARIABLES { $$ = OBJECT_VARIABLE; }
;
@@ -9942,6 +9991,24 @@ RenameStmt: ALTER AGGREGATE aggregate_with_argtypes RENAME TO name
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newname = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newname = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
opt_column: COLUMN
@@ -10303,6 +10370,24 @@ AlterObjectSchemaStmt:
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newschema = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newschema = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
/*****************************************************************************
@@ -10584,6 +10669,14 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec
n->newowner = $6;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name OWNER TO RoleSpec
+ {
+ AlterOwnerStmt *n = makeNode(AlterOwnerStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newowner = $6;
+ $$ = (Node *)n;
+ }
;
@@ -17993,6 +18086,8 @@ unreserved_keyword:
| VALIDATE
| VALIDATOR
| VALUE_P
+ | VARIABLE
+ | VARIABLES
| VARYING
| VERSION_P
| VIEW
@@ -18648,6 +18743,8 @@ bare_label_keyword:
| VALUE_P
| VALUES
| VARCHAR
+ | VARIABLE
+ | VARIABLES
| VARIADIC
| VERBOSE
| VERSION_P
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index eb7716cd84c..a7018d6628d 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -105,6 +105,7 @@ typedef struct
List *indexes; /* CREATE INDEX items */
List *triggers; /* CREATE TRIGGER items */
List *grants; /* GRANT items */
+ List *variables; /* CREATE VARIABLE items */
} CreateSchemaStmtContext;
@@ -4100,6 +4101,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.indexes = NIL;
cxt.triggers = NIL;
cxt.grants = NIL;
+ cxt.variables = NIL;
/*
* Run through each schema element in the schema element list. Separate
@@ -4168,6 +4170,15 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.grants = lappend(cxt.grants, element);
break;
+ case T_CreateSessionVarStmt:
+ {
+ CreateSessionVarStmt *elp = (CreateSessionVarStmt *) element;
+
+ setSchemaName(cxt.schemaname, &elp->variable->schemaname);
+ cxt.variables = lappend(cxt.variables, element);
+ }
+ break;
+
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(element));
@@ -4181,6 +4192,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
result = list_concat(result, cxt.indexes);
result = list_concat(result, cxt.triggers);
result = list_concat(result, cxt.grants);
+ result = list_concat(result, cxt.variables);
return result;
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 25fe3d58016..99a51877d34 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -23,6 +23,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_inherits.h"
+#include "catalog/pg_variable.h"
#include "catalog/toasting.h"
#include "commands/alter.h"
#include "commands/async.h"
@@ -182,6 +183,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CreateRangeStmt:
case T_CreateRoleStmt:
case T_CreateSchemaStmt:
+ case T_CreateSessionVarStmt:
case T_CreateSeqStmt:
case T_CreateStatsStmt:
case T_CreateStmt:
@@ -1389,6 +1391,10 @@ ProcessUtilitySlow(ParseState *pstate,
}
break;
+ case T_CreateSessionVarStmt:
+ address = CreateVariable(pstate, (CreateSessionVarStmt *) parsetree);
+ break;
+
/*
* ************* object creation / destruction **************
*/
@@ -2341,6 +2347,9 @@ AlterObjectTypeCommandTag(ObjectType objtype)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_ALTER_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_ALTER_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
break;
@@ -2649,6 +2658,9 @@ CreateCommandTag(Node *parsetree)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_DROP_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_DROP_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
@@ -3225,6 +3237,10 @@ CreateCommandTag(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ tag = CMDTAG_CREATE_VARIABLE;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
@@ -3759,6 +3775,10 @@ GetCommandLogLevel(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ lev = LOGSTMT_DDL;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index 6a76550a5e2..377de0b7c6b 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -31,6 +31,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/proclang.h"
#include "commands/tablespace.h"
@@ -129,6 +130,8 @@ static AclMode convert_type_priv_string(text *priv_type_text);
static AclMode convert_parameter_priv_string(text *priv_text);
static AclMode convert_largeobject_priv_string(text *priv_text);
static AclMode convert_role_priv_string(text *priv_type_text);
+static Oid convert_session_variable_name(text *varname);
+static AclMode convert_session_variable_priv_string(text *priv_type_text);
static AclResult pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode);
static void RoleMembershipCacheCallback(Datum arg, int cacheid, uint32 hashvalue);
@@ -851,6 +854,10 @@ acldefault(ObjectType objtype, Oid ownerId)
world_default = ACL_NO_RIGHTS;
owner_default = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ world_default = ACL_NO_RIGHTS;
+ owner_default = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", (int) objtype);
world_default = ACL_NO_RIGHTS; /* keep compiler quiet */
@@ -948,6 +955,9 @@ acldefault_sql(PG_FUNCTION_ARGS)
case 'T':
objtype = OBJECT_TYPE;
break;
+ case 'V':
+ objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type abbreviation: %c", objtypec);
}
@@ -5016,6 +5026,217 @@ pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode)
return ACLCHECK_NO_PRIV;
}
+/*
+ * has_session_variable_privilege variants
+ * These are all named "has_session_variable_privilege" at the SQL level.
+ * They take various combinations of variable name, variable OID,
+ * user name, user OID, or implicit user = current_user.
+ *
+ * The result is a boolean value: true if user has the indicated
+ * privilege, false if not, or NULL if session variable doesn't
+ * exists.
+ */
+
+/*
+ * has_session_variable_privilege_name_name
+ * Check user privileges on a session variable given
+ * name username, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_name(PG_FUNCTION_ARGS)
+{
+ Name rolename = PG_GETARG_NAME(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*rolename));
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name
+ * Check user privileges on a session variable given
+ * text session variable and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_name(PG_FUNCTION_ARGS)
+{
+ text *varname = PG_GETARG_TEXT_PP(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name_id
+ * Check user privileges on a session variable given
+ * name usename, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_id(PG_FUNCTION_ARGS)
+{
+ Name username = PG_GETARG_NAME(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*username));
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id
+ * Check user privileges on a session variable given
+ * session variable oid, and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_id(PG_FUNCTION_ARGS)
+{
+ Oid varid = PG_GETARG_OID(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_name
+ * Check user privileges on a session variable given
+ * roleid, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_name(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_id
+ * Check user privileges on a session variable given
+ * roleid, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_id(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * Given a session variable name expressed as a string, look it up and return
+ * Oid
+ */
+static Oid
+convert_session_variable_name(text *varname)
+{
+ return LookupVariableFromNameList(textToQualifiedNameList(varname), true);
+}
+
+/*
+ * convert_variable_priv_string
+ * Convert text string to AclMode value.
+ */
+static AclMode
+convert_session_variable_priv_string(text *priv_type_text)
+{
+ static const priv_map session_variable_priv_map[] = {
+ {"SELECT", ACL_SELECT},
+ {"SELECT WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_SELECT)},
+ {"UPDATE", ACL_UPDATE},
+ {"UPDATE WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_UPDATE)},
+ {NULL, 0}
+ };
+
+ return convert_any_priv_string(priv_type_text, session_variable_priv_map);
+}
/*
* initialization function (called by InitPostgres)
diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index bcfa5cb4add..f19b8bd4dc9 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -39,6 +39,7 @@
#include "catalog/pg_subscription.h"
#include "catalog/pg_transform.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "utils/array.h"
@@ -3741,3 +3742,115 @@ get_subscription_name(Oid subid, bool missing_ok)
return subname;
}
+
+/* ---------- PG_VARIABLE CACHE ---------- */
+
+/*
+ * get_varname_varid
+ * Given name and namespace of variable, look up the OID.
+ */
+Oid
+get_varname_varid(const char *varname, Oid varnamespace)
+{
+ return GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(varnamespace));
+}
+
+/*
+ * get_session_variable_name
+ * Returns a palloc'd copy of the name of a given session variable.
+ */
+char *
+get_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = pstrdup(NameStr(varform->varname));
+
+ ReleaseSysCache(tup);
+
+ return varname;
+}
+
+/*
+ * get_session_variable_namespace
+ * Returns the pg_namespace OID associated with a given session variable.
+ */
+Oid
+get_session_variable_namespace(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varnamespace = varform->varnamespace;
+
+ ReleaseSysCache(tup);
+
+ return varnamespace;
+}
+
+/*
+ * Returns the type of the given session variable.
+ */
+Oid
+get_session_variable_type(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid vartype;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ vartype = varform->vartype;
+
+ ReleaseSysCache(tup);
+
+ return vartype;
+}
+
+/*
+ * Returns the type, typmod and collid of the given session variable.
+ */
+void
+get_session_variable_type_typmod_collid(Oid varid, Oid *typid, int32 *typmod,
+ Oid *collid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ *typid = varform->vartype;
+ *typmod = varform->vartypmod;
+ *collid = varform->varcollation;
+
+ ReleaseSysCache(tup);
+}
diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c
index 56b6c368acf..ba6b19dc9af 100644
--- a/src/bin/pg_dump/common.c
+++ b/src/bin/pg_dump/common.c
@@ -246,6 +246,9 @@ getSchemaData(Archive *fout, int *numTablesPtr)
pg_log_info("reading subscription membership of tables");
getSubscriptionTables(fout);
+ pg_log_info("reading variables");
+ getVariables(fout);
+
free(inhinfo); /* not needed any longer */
*numTablesPtr = numTables;
diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index 5ae77f76367..5161ee780ea 100644
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -511,6 +511,12 @@ do { \
CONVERT_PRIV('r', "SELECT");
CONVERT_PRIV('w', "UPDATE");
}
+ else if (strcmp(type, "VARIABLE") == 0 ||
+ strcmp(type, "VARIABLES") == 0)
+ {
+ CONVERT_PRIV('r', "SELECT");
+ CONVERT_PRIV('w', "UPDATE");
+ }
else
abort();
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index f0f19bb0b29..44eed03a2ff 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -132,12 +132,14 @@ typedef struct _restoreOptions
int selFunction;
int selTrigger;
int selTable;
+ int selVariable;
SimpleStringList indexNames;
SimpleStringList functionNames;
SimpleStringList schemaNames;
SimpleStringList schemaExcludeNames;
SimpleStringList triggerNames;
SimpleStringList tableNames;
+ SimpleStringList variableNames;
int useDB;
ConnParams cparams; /* parameters to use if useDB */
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index b9d7ab98c3e..d533345ea98 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -3103,6 +3103,14 @@ _tocEntryRequired(TocEntry *te, teSection curSection, ArchiveHandle *AH)
!simple_string_list_member(&ropt->triggerNames, te->tag))
return 0;
}
+ else if (strcmp(te->desc, "VARIABLE") == 0)
+ {
+ if (!ropt->selVariable)
+ return 0;
+ if (ropt->variableNames.head != NULL &&
+ !simple_string_list_member(&ropt->variableNames, te->tag))
+ return 0;
+ }
else
return 0;
}
@@ -3652,6 +3660,7 @@ _getObjectDescription(PQExpBuffer buf, const TocEntry *te)
strcmp(type, "TEXT SEARCH DICTIONARY") == 0 ||
strcmp(type, "TEXT SEARCH CONFIGURATION") == 0 ||
strcmp(type, "TYPE") == 0 ||
+ strcmp(type, "VARIABLE") == 0 ||
strcmp(type, "VIEW") == 0 ||
/* non-schema-specified objects */
strcmp(type, "DATABASE") == 0 ||
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 30dfda8c3ff..4771ab5494a 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -364,6 +364,7 @@ static void dumpPublication(Archive *fout, const PublicationInfo *pubinfo);
static void dumpPublicationTable(Archive *fout, const PublicationRelInfo *pubrinfo);
static void dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo);
static void dumpSubscriptionTable(Archive *fout, const SubRelInfo *subrinfo);
+static void dumpVariable(Archive *fout, const VariableInfo *varinfo);
static void dumpDatabase(Archive *fout);
static void dumpDatabaseConfig(Archive *AH, PQExpBuffer outbuf,
const char *dbname, Oid dboid);
@@ -5423,6 +5424,188 @@ get_next_possible_free_pg_type_oid(Archive *fout, PQExpBuffer upgrade_query)
return next_possible_free_oid;
}
+/*
+ * getVariables
+ * get information about variables
+ */
+void
+getVariables(Archive *fout)
+{
+ PQExpBuffer query;
+ PGresult *res;
+ VariableInfo *varinfo;
+ int i_tableoid;
+ int i_oid;
+ int i_varname;
+ int i_varnamespace;
+ int i_vartype;
+ int i_vartypname;
+ int i_varowner;
+ int i_varcollation;
+ int i_varacl;
+ int i_acldefault;
+ int i,
+ ntups;
+
+ if (fout->remoteVersion < 180000)
+ return;
+
+ query = createPQExpBuffer();
+
+ /* get the variables in current database */
+ appendPQExpBuffer(query,
+ "SELECT v.tableoid, v.oid, v.varname,\n"
+ " v.varnamespace, v.vartype,\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n"
+ " CASE WHEN v.varcollation <> t.typcollation "
+ " THEN v.varcollation\n"
+ " ELSE 0\n"
+ " END AS varcollation,\n"
+ " v.varowner, v.varacl,\n"
+ " acldefault('V', v.varowner) AS acldefault\n"
+ "FROM pg_catalog.pg_variable v\n"
+ "JOIN pg_catalog.pg_type t "
+ "ON (v.vartype = t.oid)");
+
+ res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK);
+
+ ntups = PQntuples(res);
+
+ i_tableoid = PQfnumber(res, "tableoid");
+ i_oid = PQfnumber(res, "oid");
+ i_varname = PQfnumber(res, "varname");
+ i_varnamespace = PQfnumber(res, "varnamespace");
+ i_vartype = PQfnumber(res, "vartype");
+ i_vartypname = PQfnumber(res, "vartypname");
+ i_varcollation = PQfnumber(res, "varcollation");
+
+ i_varowner = PQfnumber(res, "varowner");
+ i_varacl = PQfnumber(res, "varacl");
+ i_acldefault = PQfnumber(res, "acldefault");
+
+ varinfo = pg_malloc(ntups * sizeof(VariableInfo));
+
+ for (i = 0; i < ntups; i++)
+ {
+ TypeInfo *vtype;
+
+ varinfo[i].dobj.objType = DO_VARIABLE;
+ varinfo[i].dobj.catId.tableoid =
+ atooid(PQgetvalue(res, i, i_tableoid));
+ varinfo[i].dobj.catId.oid = atooid(PQgetvalue(res, i, i_oid));
+ AssignDumpId(&varinfo[i].dobj);
+ varinfo[i].dobj.name = pg_strdup(PQgetvalue(res, i, i_varname));
+ varinfo[i].dobj.namespace =
+ findNamespace(atooid(PQgetvalue(res, i, i_varnamespace)));
+
+ varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype));
+ varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname));
+ varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
+
+ varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
+ varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
+ varinfo[i].dacl.privtype = 0;
+ varinfo[i].dacl.initprivs = NULL;
+ varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner));
+
+ /* do not try to dump ACL if no ACL exists */
+ if (!PQgetisnull(res, i, i_varacl))
+ varinfo[i].dobj.components |= DUMP_COMPONENT_ACL;
+
+ if (strlen(varinfo[i].rolname) == 0)
+ pg_log_warning("owner of variable \"%s\" appears to be invalid",
+ varinfo[i].dobj.name);
+
+ /* decide whether we want to dump it */
+ selectDumpableObject(&(varinfo[i].dobj), fout);
+
+ vtype = findTypeByOid(varinfo[i].vartype);
+ addObjectDependency(&varinfo[i].dobj, vtype->dobj.dumpId);
+ }
+ PQclear(res);
+
+ destroyPQExpBuffer(query);
+}
+
+/*
+ * dumpVariable
+ * dump the definition of the given session variable
+ */
+static void
+dumpVariable(Archive *fout, const VariableInfo *varinfo)
+{
+ DumpOptions *dopt = fout->dopt;
+
+ PQExpBuffer delq;
+ PQExpBuffer query;
+ char *qualvarname;
+ const char *vartypname;
+ Oid varcollation;
+
+ /* skip if not to be dumped */
+ if (!varinfo->dobj.dump || !dopt->dumpSchema)
+ return;
+
+ delq = createPQExpBuffer();
+ query = createPQExpBuffer();
+
+ qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
+ vartypname = varinfo->vartypname;
+ varcollation = varinfo->varcollation;
+
+ appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
+ qualvarname);
+
+ appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s",
+ qualvarname, vartypname);
+
+ if (OidIsValid(varcollation))
+ {
+ CollInfo *coll;
+
+ coll = findCollationByOid(varcollation);
+ if (coll)
+ appendPQExpBuffer(query, " COLLATE %s",
+ fmtQualifiedDumpable(coll));
+ }
+
+ appendPQExpBuffer(query, ";\n");
+
+ if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
+ ArchiveEntry(fout, varinfo->dobj.catId, varinfo->dobj.dumpId,
+ ARCHIVE_OPTS(.tag = varinfo->dobj.name,
+ .namespace = varinfo->dobj.namespace->dobj.name,
+ .owner = varinfo->rolname,
+ .description = "VARIABLE",
+ .section = SECTION_PRE_DATA,
+ .createStmt = query->data,
+ .dropStmt = delq->data));
+
+ /* dump comment if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_COMMENT)
+ dumpComment(fout, "VARIABLE", qualvarname,
+ NULL, varinfo->rolname,
+ varinfo->dobj.catId, 0, varinfo->dobj.dumpId);
+
+ /* dump ACL if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_ACL)
+ {
+ char *qvarname = pg_strdup(fmtId(varinfo->dobj.name));
+
+ dumpACL(fout, varinfo->dobj.dumpId, InvalidDumpId, "VARIABLE",
+ qvarname, NULL,
+ varinfo->dobj.namespace->dobj.name, NULL, varinfo->rolname,
+ &varinfo->dacl);
+
+ free(qvarname);
+ }
+
+ destroyPQExpBuffer(delq);
+ destroyPQExpBuffer(query);
+
+ free(qualvarname);
+}
+
static void
binary_upgrade_set_type_oids_by_type_oid(Archive *fout,
PQExpBuffer upgrade_buffer,
@@ -10749,6 +10932,9 @@ dumpDumpableObject(Archive *fout, DumpableObject *dobj)
case DO_SUBSCRIPTION_REL:
dumpSubscriptionTable(fout, (const SubRelInfo *) dobj);
break;
+ case DO_VARIABLE:
+ dumpVariable(fout, (VariableInfo *) dobj);
+ break;
case DO_PRE_DATA_BOUNDARY:
case DO_POST_DATA_BOUNDARY:
/* never dumped, nothing to do */
@@ -15200,6 +15386,9 @@ dumpDefaultACL(Archive *fout, const DefaultACLInfo *daclinfo)
case DEFACLOBJ_NAMESPACE:
type = "SCHEMAS";
break;
+ case DEFACLOBJ_VARIABLE:
+ type = "VARIABLES";
+ break;
default:
/* shouldn't get here */
pg_fatal("unrecognized object type in default privileges: %d",
@@ -18922,6 +19111,7 @@ addBoundaryDependencies(DumpableObject **dobjs, int numObjs,
case DO_CONVERSION:
case DO_TABLE:
case DO_TABLE_ATTACH:
+ case DO_VARIABLE:
case DO_ATTRDEF:
case DO_PROCLANG:
case DO_CAST:
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index 7139c88a69a..125384cf3f0 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -53,6 +53,7 @@ typedef enum
DO_TABLE,
DO_TABLE_ATTACH,
DO_ATTRDEF,
+ DO_VARIABLE,
DO_INDEX,
DO_INDEX_ATTACH,
DO_STATSEXT,
@@ -708,6 +709,19 @@ typedef struct _SubRelInfo
char *srsublsn;
} SubRelInfo;
+/*
+ * The VariableInfo struct is used to represent session variables
+ */
+typedef struct _VariableInfo
+{
+ DumpableObject dobj;
+ DumpableAcl dacl;
+ Oid vartype;
+ char *vartypname;
+ Oid varcollation;
+ const char *rolname; /* name of owner, or empty string */
+} VariableInfo;
+
/*
* common utility functions
*/
@@ -791,5 +805,6 @@ extern void getPublicationTables(Archive *fout, TableInfo tblinfo[],
int numTables);
extern void getSubscriptions(Archive *fout);
extern void getSubscriptionTables(Archive *fout);
+extern void getVariables(Archive *fout);
#endif /* PG_DUMP_H */
diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c
index dc9a28924bd..842973f1128 100644
--- a/src/bin/pg_dump/pg_dump_sort.c
+++ b/src/bin/pg_dump/pg_dump_sort.c
@@ -77,6 +77,7 @@ enum dbObjectTypePriorities
PRIO_DUMMY_TYPE,
PRIO_ATTRDEF,
PRIO_LARGE_OBJECT,
+ PRIO_VARIABLE,
PRIO_PRE_DATA_BOUNDARY, /* boundary! */
PRIO_TABLE_DATA,
PRIO_SEQUENCE_SET,
@@ -118,6 +119,7 @@ static const int dbObjectTypePriority[] =
[DO_TABLE] = PRIO_TABLE,
[DO_TABLE_ATTACH] = PRIO_TABLE_ATTACH,
[DO_ATTRDEF] = PRIO_ATTRDEF,
+ [DO_VARIABLE] = PRIO_VARIABLE,
[DO_INDEX] = PRIO_INDEX,
[DO_INDEX_ATTACH] = PRIO_INDEX_ATTACH,
[DO_STATSEXT] = PRIO_STATSEXT,
@@ -1500,6 +1502,10 @@ describeDumpableObject(DumpableObject *obj, char *buf, int bufsize)
"POST-DATA BOUNDARY (ID %d)",
obj->dumpId);
return;
+ case DO_VARIABLE:
+ snprintf(buf, bufsize,
+ "VARIABLE %s (ID %d OID %u)",
+ obj->name, obj->dumpId, obj->catId.oid);
}
/* shouldn't get here */
snprintf(buf, bufsize,
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index bc5d9222a20..b84dcf0cab9 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -854,6 +854,16 @@ my %tests = (
unlike => { no_privs => 1, },
},
+ 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC'
+ => {
+ create_order => 56,
+ create_sql => 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;',
+ regexp => qr/^
+ \QALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;\E/xm,
+ like => { %full_runs, section_post_data => 1, },
+ unlike => { no_privs => 1, },
+ },
+
'ALTER ROLE regress_dump_test_role' => {
regexp => qr/^
\QALTER ROLE regress_dump_test_role WITH \E
@@ -1739,6 +1749,23 @@ my %tests = (
},
},
+ 'COMMENT ON VARIABLE dump_test.variable1' => {
+ create_order => 71,
+ create_sql => 'COMMENT ON VARIABLE dump_test.variable1
+ IS \'comment on variable\';',
+ regexp =>
+ qr/^\QCOMMENT ON VARIABLE dump_test.variable1 IS 'comment on variable';\E/m,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'COPY test_table' => {
create_order => 4,
create_sql => 'INSERT INTO dump_test.test_table (col1) '
@@ -4009,6 +4036,24 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable1 AS integer;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable1 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
@@ -4471,6 +4516,25 @@ my %tests = (
like => {},
},
+ 'GRANT SELECT ON VARIABLE dump_test.variable1' => {
+ create_order => 73,
+ create_sql =>
+ 'GRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;',
+ regexp => qr/^
+ \QGRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;\E
+ /xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ no_privs => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'REFRESH MATERIALIZED VIEW matview' => {
regexp => qr/^\QREFRESH MATERIALIZED VIEW dump_test.matview;\E/m,
like =>
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 26dfdde195a..6b870e2fc60 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -1097,6 +1097,9 @@ exec_command_d(PsqlScanState scan_state, bool active_branch, const char *cmd)
break;
}
break;
+ case 'V': /* Variables */
+ success = listVariables(pattern, show_verbose);
+ break;
case 'x': /* Extensions */
if (show_verbose)
success = listExtensionContents(pattern);
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 3b7ba66fad0..576ac986ef9 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -1222,7 +1222,7 @@ listDefaultACLs(const char *pattern)
printfPQExpBuffer(&buf,
"SELECT pg_catalog.pg_get_userbyid(d.defaclrole) AS \"%s\",\n"
" n.nspname AS \"%s\",\n"
- " CASE d.defaclobjtype WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
+ " CASE d.defaclobjtype WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
" ",
gettext_noop("Owner"),
gettext_noop("Schema"),
@@ -1236,6 +1236,8 @@ listDefaultACLs(const char *pattern)
gettext_noop("type"),
DEFACLOBJ_NAMESPACE,
gettext_noop("schema"),
+ DEFACLOBJ_VARIABLE,
+ gettext_noop("session variable"),
gettext_noop("Type"));
printACLColumn(&buf, "d.defaclacl");
@@ -5318,6 +5320,102 @@ error_return:
return false;
}
+/*
+ * \dV
+ *
+ * listVariables()
+ */
+bool
+listVariables(const char *pattern, bool verbose)
+{
+ PQExpBufferData buf;
+ PGresult *res;
+ printQueryOpt myopt = pset.popt;
+ static const bool translate_columns[] = {false, false, false, false, false, false, false};
+
+ if (pset.sversion < 180000)
+ {
+ char sverbuf[32];
+
+ pg_log_error("The server (version %s) does not support session variables.",
+ formatPGVersionNumber(pset.sversion, false,
+ sverbuf, sizeof(sverbuf)));
+ return true;
+ }
+
+ initPQExpBuffer(&buf);
+
+ printfPQExpBuffer(&buf,
+ "SELECT n.nspname as \"%s\",\n"
+ " v.varname as \"%s\",\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n"
+ " (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
+ " WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
+ " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n",
+ gettext_noop("Schema"),
+ gettext_noop("Name"),
+ gettext_noop("Type"),
+ gettext_noop("Collation"),
+ gettext_noop("Owner"));
+
+ if (verbose)
+ {
+ appendPQExpBufferStr(&buf, ",\n ");
+ printACLColumn(&buf, "v.varacl");
+ appendPQExpBuffer(&buf,
+ ",\n pg_catalog.obj_description(v.oid, 'pg_variable') AS \"%s\"",
+ gettext_noop("Description"));
+ }
+
+ appendPQExpBufferStr(&buf,
+ "\nFROM pg_catalog.pg_variable v"
+ "\n LEFT JOIN pg_catalog.pg_namespace n ON n.oid = v.varnamespace");
+
+ appendPQExpBufferStr(&buf, "\nWHERE true\n");
+ if (!pattern)
+ appendPQExpBufferStr(&buf, " AND n.nspname <> 'pg_catalog'\n"
+ " AND n.nspname <> 'information_schema'\n");
+
+ if (!validateSQLNamePattern(&buf, pattern, true, false,
+ "n.nspname", "v.varname", NULL,
+ "pg_catalog.pg_variable_is_visible(v.oid)",
+ NULL, 3))
+ return false;
+
+ appendPQExpBufferStr(&buf, "ORDER BY 1,2;");
+
+ res = PSQLexec(buf.data);
+ termPQExpBuffer(&buf);
+ if (!res)
+ return false;
+
+ /*
+ * Most functions in this file are content to print an empty table when
+ * there are no matching objects. We intentionally deviate from that
+ * here, but only in !quiet mode, for historical reasons.
+ */
+ if (PQntuples(res) == 0 && !pset.quiet)
+ {
+ if (pattern)
+ pg_log_error("Did not find any session variable named \"%s\".",
+ pattern);
+ else
+ pg_log_error("Did not find any session variables.");
+ }
+ else
+ {
+ myopt.nullPrint = NULL;
+ myopt.title = _("List of variables");
+ myopt.translate_header = true;
+ myopt.translate_columns = translate_columns;
+ myopt.n_translate_columns = lengthof(translate_columns);
+
+ printQuery(res, &myopt, pset.queryFout, false, pset.logfile);
+ }
+
+ PQclear(res);
+ return true;
+}
/*
* \dFp
diff --git a/src/bin/psql/describe.h b/src/bin/psql/describe.h
index 18ecaa60949..55ced4aab7b 100644
--- a/src/bin/psql/describe.h
+++ b/src/bin/psql/describe.h
@@ -149,4 +149,7 @@ extern bool listOpFamilyFunctions(const char *access_method_pattern,
/* \dl or \lo_list */
extern bool listLargeObjects(bool verbose);
+/* \dV */
+extern bool listVariables(const char *pattern, bool varbose);
+
#endif /* DESCRIBE_H */
diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index da8e1ade5df..9a02a0986d4 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -266,6 +266,7 @@ slashUsage(unsigned short int pager)
HELP0(" \\dT[Sx+] [PATTERN] list data types\n");
HELP0(" \\du[Sx+] [PATTERN] list roles\n");
HELP0(" \\dv[Sx+] [PATTERN] list views\n");
+ HELP0(" \\dV[x+] [PATTERN] list session variables\n");
HELP0(" \\dx[x+] [PATTERN] list extensions\n");
HELP0(" \\dX[x] [PATTERN] list extended statistics\n");
HELP0(" \\dy[x+] [PATTERN] list event triggers\n");
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index a9a81ab3c14..c6a1bb09f3f 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -970,6 +970,13 @@ static const SchemaQuery Query_for_trigger_of_table = {
.refnamespace = "c1.relnamespace",
};
+static const SchemaQuery Query_for_list_of_variables = {
+ .min_server_version = 180000,
+ .catname = "pg_catalog.pg_variable v",
+ .viscondition = "pg_catalog.pg_variable_is_visible(v.oid)",
+ .namespace = "v.varnamespace",
+ .result = "v.varname",
+};
/*
* Queries to get lists of names of various kinds of things, possibly
@@ -1304,6 +1311,7 @@ static const pgsql_thing_t words_after_create[] = {
* TABLE ... */
{"USER", Query_for_list_of_roles, NULL, NULL, Keywords_for_user_thing},
{"USER MAPPING FOR", NULL, NULL, NULL},
+ {"VARIABLE", NULL, NULL, &Query_for_list_of_variables},
{"VIEW", NULL, NULL, &Query_for_list_of_views},
{NULL} /* end of list */
};
@@ -1869,7 +1877,7 @@ psql_completion(const char *text, int start, int end)
"\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL",
"\\dm", "\\dn", "\\do", "\\dO", "\\dp", "\\dP", "\\dPi", "\\dPt",
"\\drds", "\\drg", "\\dRs", "\\dRp", "\\ds",
- "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy",
+ "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy", "\\dV",
"\\echo", "\\edit", "\\ef", "\\elif", "\\else", "\\encoding",
"\\endif", "\\errverbose", "\\ev",
"\\f",
@@ -2560,6 +2568,9 @@ match_previous_words(int pattern_id,
"ALL");
else if (Matches("ALTER", "SYSTEM", "SET", MatchAny))
COMPLETE_WITH("TO");
+ /* ALTER VARIABLE <name> */
+ else if (Matches("ALTER", "VARIABLE", MatchAny))
+ COMPLETE_WITH("OWNER TO", "RENAME TO", "SET SCHEMA");
/* ALTER VIEW <name> */
else if (Matches("ALTER", "VIEW", MatchAny))
COMPLETE_WITH("ALTER COLUMN", "OWNER TO", "RENAME", "RESET", "SET");
@@ -3140,7 +3151,7 @@ match_previous_words(int pattern_id,
"ROUTINE", "RULE", "SCHEMA", "SEQUENCE", "SERVER",
"STATISTICS", "SUBSCRIPTION", "TABLE",
"TABLESPACE", "TEXT SEARCH", "TRANSFORM FOR",
- "TRIGGER", "TYPE", "VIEW");
+ "TRIGGER", "TYPE", "VARIABLE", "VIEW");
else if (Matches("COMMENT", "ON", "ACCESS", "METHOD"))
COMPLETE_WITH_QUERY(Query_for_list_of_access_methods);
else if (Matches("COMMENT", "ON", "CONSTRAINT"))
@@ -3950,6 +3961,13 @@ match_previous_words(int pattern_id,
else if (TailMatches("=", MatchAnyExcept("*)")))
COMPLETE_WITH(",", ")");
}
+/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
+ /* Complete CREATE VARIABLE <name> with AS */
+ else if (TailMatches("CREATE", "VARIABLE", MatchAny))
+ COMPLETE_WITH("AS");
+ else if (TailMatches("VARIABLE", MatchAny, "AS"))
+ /* Complete CREATE VARIABLE <name> with AS types */
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
/* CREATE VIEW --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE [ OR REPLACE ] VIEW <name> with AS or WITH */
@@ -4227,6 +4245,12 @@ match_previous_words(int pattern_id,
else if (Matches("DROP", "TRANSFORM", "FOR", MatchAny, "LANGUAGE", MatchAny))
COMPLETE_WITH("CASCADE", "RESTRICT");
+ /* DROP VARIABLE */
+ else if (Matches("DROP", "VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ else if (Matches("DROP", "VARIABLE", MatchAny))
+ COMPLETE_WITH("CASCADE", "RESTRICT");
+
/* EXECUTE */
else if (Matches("EXECUTE"))
COMPLETE_WITH_QUERY(Query_for_list_of_prepared_statements);
@@ -4428,7 +4452,7 @@ match_previous_words(int pattern_id,
* objects supported.
*/
if (HeadMatches("ALTER", "DEFAULT", "PRIVILEGES"))
- COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS");
+ COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS", "VARIABLES");
else
COMPLETE_WITH_SCHEMA_QUERY_PLUS(Query_for_list_of_grantables,
"ALL FUNCTIONS IN SCHEMA",
@@ -4436,6 +4460,7 @@ match_previous_words(int pattern_id,
"ALL ROUTINES IN SCHEMA",
"ALL SEQUENCES IN SCHEMA",
"ALL TABLES IN SCHEMA",
+ "ALL VARIABLES IN SCHEMA",
"DATABASE",
"DOMAIN",
"FOREIGN DATA WRAPPER",
@@ -4450,7 +4475,8 @@ match_previous_words(int pattern_id,
"SEQUENCE",
"TABLE",
"TABLESPACE",
- "TYPE");
+ "TYPE",
+ "VARIABLE");
}
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "ALL") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "ALL"))
@@ -4458,7 +4484,8 @@ match_previous_words(int pattern_id,
"PROCEDURES IN SCHEMA",
"ROUTINES IN SCHEMA",
"SEQUENCES IN SCHEMA",
- "TABLES IN SCHEMA");
+ "TABLES IN SCHEMA",
+ "VARIABLES IN SCHEMA");
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "FOREIGN") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "FOREIGN"))
COMPLETE_WITH("DATA WRAPPER", "SERVER");
@@ -4494,6 +4521,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_tablespaces);
else if (TailMatches("TYPE"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
+ else if (TailMatches("VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatches("GRANT", MatchAny, MatchAny, MatchAny))
COMPLETE_WITH("TO");
else
@@ -4796,7 +4825,7 @@ match_previous_words(int pattern_id,
/* PREPARE xx AS */
else if (Matches("PREPARE", MatchAny, "AS"))
- COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM");
+ COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM", "LET");
/*
* PREPARE TRANSACTION is missing on purpose. It's intended for transaction
@@ -5278,6 +5307,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_roles);
else if (TailMatchesCS("\\dv*"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_views);
+ else if (TailMatchesCS("\\dV*"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatchesCS("\\dx*"))
COMPLETE_WITH_QUERY(Query_for_list_of_extensions);
else if (TailMatchesCS("\\dX*"))
diff --git a/src/include/catalog/Makefile b/src/include/catalog/Makefile
index 2bbc7805fe3..f98760de635 100644
--- a/src/include/catalog/Makefile
+++ b/src/include/catalog/Makefile
@@ -81,7 +81,8 @@ CATALOG_HEADERS := \
pg_publication_namespace.h \
pg_publication_rel.h \
pg_subscription.h \
- pg_subscription_rel.h
+ pg_subscription_rel.h \
+ pg_variable.h
GENERATED_HEADERS := $(CATALOG_HEADERS:%.h=%_d.h)
diff --git a/src/include/catalog/meson.build b/src/include/catalog/meson.build
index ec1cf467f6f..81398efa7c9 100644
--- a/src/include/catalog/meson.build
+++ b/src/include/catalog/meson.build
@@ -69,6 +69,7 @@ catalog_headers = [
'pg_publication_rel.h',
'pg_subscription.h',
'pg_subscription_rel.h',
+ 'pg_variable.h',
]
# The .dat files we need can just be listed alphabetically.
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index 8c7ccc69a3c..bdac0c13bec 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -97,6 +97,8 @@ extern Oid TypenameGetTypid(const char *typname);
extern Oid TypenameGetTypidExtended(const char *typname, bool temp_ok);
extern bool TypeIsVisible(Oid typid);
+extern bool VariableIsVisible(Oid varid);
+
extern FuncCandidateList FuncnameGetCandidates(List *names,
int nargs, List *argnames,
bool expand_variadic,
@@ -169,6 +171,10 @@ extern SearchPathMatcher *GetSearchPathMatcher(MemoryContext context);
extern SearchPathMatcher *CopySearchPathMatcher(SearchPathMatcher *path);
extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
+extern List *NamesFromList(List *names);
+extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
+extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
extern Oid FindDefaultConversionProc(int32 for_encoding, int32 to_encoding);
diff --git a/src/include/catalog/pg_default_acl.h b/src/include/catalog/pg_default_acl.h
index 728024b1fa7..5f94424a684 100644
--- a/src/include/catalog/pg_default_acl.h
+++ b/src/include/catalog/pg_default_acl.h
@@ -68,6 +68,7 @@ MAKE_SYSCACHE(DEFACLROLENSPOBJ, pg_default_acl_role_nsp_obj_index, 8);
#define DEFACLOBJ_FUNCTION 'f' /* function */
#define DEFACLOBJ_TYPE 'T' /* type */
#define DEFACLOBJ_NAMESPACE 'n' /* namespace */
+#define DEFACLOBJ_VARIABLE 'V' /* variable */
#endif /* EXPOSE_TO_CLIENT_CODE */
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 9e803d610d7..162cd048965 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5404,6 +5404,26 @@
prorettype => 'bool', proargtypes => 'oid oid text',
prosrc => 'has_largeobject_privilege_id_id' },
+{ oid => '9613', descr => 'user privilege on session variable by username, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name text text',
+ prosrc => 'has_session_variable_privilege_name_name' },
+{ oid => '9614', descr => 'user privilege on session variable by username, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name oid text', prosrc => 'has_session_variable_privilege_name_id' },
+{ oid => '9615', descr => 'user privilege on session variable by user oid, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text text', prosrc => 'has_session_variable_privilege_id_name' },
+{ oid => '9616', descr => 'user privilege on session variable by user oid, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid oid text', prosrc => 'has_session_variable_privilege_id_id' },
+{ oid => '9617', descr => 'current user privilege on session variable by seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'text text', prosrc => 'has_session_variable_privilege_name' },
+{ oid => '9618', descr => 'current user privilege on session variable by seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text', prosrc => 'has_session_variable_privilege_id' },
+
{ oid => '3355', descr => 'I/O',
proname => 'pg_ndistinct_in', prorettype => 'pg_ndistinct',
proargtypes => 'cstring', prosrc => 'pg_ndistinct_in' },
@@ -6604,6 +6624,9 @@
proname => 'pg_collation_is_visible', procost => '10', provolatile => 's',
prorettype => 'bool', proargtypes => 'oid',
prosrc => 'pg_collation_is_visible' },
+{ oid => '9999', descr => 'is session variable visible in search path?',
+ proname => 'pg_variable_is_visible', procost => '10', provolatile => 's',
+ prorettype => 'bool', proargtypes => 'oid', prosrc => 'pg_variable_is_visible' },
{ oid => '2854', descr => 'get OID of current session\'s temp schema, if any',
proname => 'pg_my_temp_schema', provolatile => 's', proparallel => 'r',
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
new file mode 100644
index 00000000000..3d3c6eb24b5
--- /dev/null
+++ b/src/include/catalog/pg_variable.h
@@ -0,0 +1,81 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.h
+ * definition of session variables system catalog (pg_variables)
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/catalog/pg_variable.h
+ *
+ * NOTES
+ * The Catalog.pm module reads this file and derives schema
+ * information.
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_VARIABLE_H
+#define PG_VARIABLE_H
+
+#include "catalog/genbki.h"
+#include "catalog/objectaddress.h"
+#include "catalog/pg_variable_d.h"
+#include "utils/acl.h"
+
+/* ----------------
+ * pg_variable definition. cpp turns this into
+ * typedef struct FormData_pg_variable
+ * ----------------
+ */
+CATALOG(pg_variable,9222,VariableRelationId)
+{
+ Oid oid; /* oid */
+
+ /* OID of entry in pg_type for variable's type */
+ Oid vartype BKI_LOOKUP(pg_type);
+
+ /* variable name */
+ NameData varname;
+
+ /* OID of namespace containing variable class */
+ Oid varnamespace BKI_LOOKUP(pg_namespace);
+
+ /* variable owner */
+ Oid varowner BKI_LOOKUP(pg_authid);
+
+ /* typmod for variable's type */
+ int32 vartypmod BKI_DEFAULT(-1);
+
+ /* variable collation */
+ Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation);
+
+
+#ifdef CATALOG_VARLEN /* variable-length fields start here */
+
+ /* access permissions */
+ aclitem varacl[1] BKI_DEFAULT(_null_);
+
+#endif
+} FormData_pg_variable;
+
+/* ----------------
+ * Form_pg_variable corresponds to a pointer to a tuple with
+ * the format of the pg_variable relation.
+ * ----------------
+ */
+typedef FormData_pg_variable *Form_pg_variable;
+
+DECLARE_TOAST(pg_variable, 9223, 9224);
+
+DECLARE_UNIQUE_INDEX_PKEY(pg_variable_oid_index, 9225, VariableOidIndexId, pg_variable, btree(oid oid_ops));
+DECLARE_UNIQUE_INDEX(pg_variable_varname_nsp_index, 9226, VariableNameNspIndexId, pg_variable, btree(varname name_ops, varnamespace oid_ops));
+
+extern ObjectAddress CreateVariable(ParseState *pstate,
+ CreateSessionVarStmt *stmt);
+extern void DropVariableById(Oid varid);
+
+MAKE_SYSCACHE(VARIABLENAMENSP, pg_variable_varname_nsp_index, 8);
+MAKE_SYSCACHE(VARIABLEOID, pg_variable_oid_index, 8);
+
+#endif /* PG_VARIABLE_H */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 8dd421fa0ef..b07c42f94d0 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2360,6 +2360,7 @@ typedef enum ObjectType
OBJECT_TSTEMPLATE,
OBJECT_TYPE,
OBJECT_USER_MAPPING,
+ OBJECT_VARIABLE,
OBJECT_VIEW,
} ObjectType;
@@ -3495,6 +3496,21 @@ typedef struct AlterStatsStmt
bool missing_ok; /* skip error if statistics object is missing */
} AlterStatsStmt;
+
+/* ----------------------
+ * {Create|Alter} VARIABLE Statement
+ * ----------------------
+ */
+typedef struct CreateSessionVarStmt
+{
+ NodeTag type;
+ RangeVar *variable; /* the variable to create */
+ TypeName *typeName; /* the type of variable */
+ CollateClause *collClause;
+ bool if_not_exists; /* do nothing if it already exists */
+} CreateSessionVarStmt;
+
+
/* ----------------------
* Create Function Statement
* ----------------------
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 40cf090ce61..793ace526df 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -485,6 +485,8 @@ PG_KEYWORD("validator", VALIDATOR, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("value", VALUE_P, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("values", VALUES, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("varchar", VARCHAR, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variable", VARIABLE, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variables", VARIABLES, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("variadic", VARIADIC, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("varying", VARYING, UNRESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("verbose", VERBOSE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index d250a714d59..ea86954dded 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -68,6 +68,7 @@ PG_CMDTAG(CMDTAG_ALTER_TRANSFORM, "ALTER TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TRIGGER, "ALTER TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TYPE, "ALTER TYPE", true, true, false)
PG_CMDTAG(CMDTAG_ALTER_USER_MAPPING, "ALTER USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_ALTER_VARIABLE, "ALTER VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_VIEW, "ALTER VIEW", true, false, false)
PG_CMDTAG(CMDTAG_ANALYZE, "ANALYZE", false, false, false)
PG_CMDTAG(CMDTAG_BEGIN, "BEGIN", false, false, false)
@@ -123,6 +124,7 @@ PG_CMDTAG(CMDTAG_CREATE_TRANSFORM, "CREATE TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TRIGGER, "CREATE TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TYPE, "CREATE TYPE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_USER_MAPPING, "CREATE USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_CREATE_VARIABLE, "CREATE VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_VIEW, "CREATE VIEW", true, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE, "DEALLOCATE", false, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE_ALL, "DEALLOCATE ALL", false, false, false)
@@ -175,6 +177,7 @@ PG_CMDTAG(CMDTAG_DROP_TRANSFORM, "DROP TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TRIGGER, "DROP TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TYPE, "DROP TYPE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_USER_MAPPING, "DROP USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_DROP_VARIABLE, "DROP VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_VIEW, "DROP VIEW", true, false, false)
PG_CMDTAG(CMDTAG_EXECUTE, "EXECUTE", false, false, false)
PG_CMDTAG(CMDTAG_EXPLAIN, "EXPLAIN", false, false, false)
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index 01ae5b719fd..5e1a8a82e90 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -169,6 +169,7 @@ typedef struct ArrayType Acl;
#define ACL_ALL_RIGHTS_SCHEMA (ACL_USAGE|ACL_CREATE)
#define ACL_ALL_RIGHTS_TABLESPACE (ACL_CREATE)
#define ACL_ALL_RIGHTS_TYPE (ACL_USAGE)
+#define ACL_ALL_RIGHTS_VARIABLE (ACL_SELECT|ACL_UPDATE)
/* operation codes for pg_*_aclmask */
typedef enum
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 6fab7aa6009..9503b528647 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -135,6 +135,7 @@ extern char get_func_prokind(Oid funcid);
extern bool get_func_leakproof(Oid funcid);
extern RegProcedure get_func_support(Oid funcid);
extern Oid get_relname_relid(const char *relname, Oid relnamespace);
+extern Oid get_varname_varid(const char *varname, Oid varnamespace);
extern char *get_rel_name(Oid relid);
extern Oid get_rel_namespace(Oid relid);
extern Oid get_rel_type_id(Oid relid);
@@ -207,6 +208,14 @@ extern char *get_publication_name(Oid pubid, bool missing_ok);
extern Oid get_subscription_oid(const char *subname, bool missing_ok);
extern char *get_subscription_name(Oid subid, bool missing_ok);
+extern char *get_session_variable_name(Oid varid);
+extern Oid get_session_variable_namespace(Oid varid);
+extern Oid get_session_variable_type(Oid varid);
+extern void get_session_variable_type_typmod_collid(Oid varid,
+ Oid *typid,
+ int32 *typmod,
+ Oid *collid);
+
#define type_is_array(typid) (get_element_type(typid) != InvalidOid)
/* type_is_array_domain accepts both plain arrays and domains over arrays */
#define type_is_array_domain(typid) (get_base_element_type(typid) != InvalidOid)
diff --git a/src/test/regress/expected/dependency.out b/src/test/regress/expected/dependency.out
index 75a078ada9e..cd8e4412fa9 100644
--- a/src/test/regress/expected/dependency.out
+++ b/src/test/regress/expected/dependency.out
@@ -151,3 +151,20 @@ owner of type deptest_t
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+-- should fail
+DROP DOMAIN vardomain;
+ERROR: cannot drop type vardomain because other objects depend on it
+DETAIL: column c of composite type vartype depends on type vardomain
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP TYPE vartype;
+ERROR: cannot drop type vartype because other objects depend on it
+DETAIL: session variable var1 depends on type vartype
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/expected/oidjoins.out b/src/test/regress/expected/oidjoins.out
index 215eb899be3..d9953321402 100644
--- a/src/test/regress/expected/oidjoins.out
+++ b/src/test/regress/expected/oidjoins.out
@@ -266,3 +266,7 @@ NOTICE: checking pg_subscription {subdbid} => pg_database {oid}
NOTICE: checking pg_subscription {subowner} => pg_authid {oid}
NOTICE: checking pg_subscription_rel {srsubid} => pg_subscription {oid}
NOTICE: checking pg_subscription_rel {srrelid} => pg_class {oid}
+NOTICE: checking pg_variable {vartype} => pg_type {oid}
+NOTICE: checking pg_variable {varnamespace} => pg_namespace {oid}
+NOTICE: checking pg_variable {varowner} => pg_authid {oid}
+NOTICE: checking pg_variable {varcollation} => pg_collation {oid}
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index f9db4032e1f..0c48fdfaf61 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6015,6 +6015,30 @@ COMMIT;
# final ON_ERROR_ROLLBACK: off
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | |
+(1 row)
+
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | =r/regress_variable_owner |
+(1 row)
+
+DROP VARIABLE var1;
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
-- check describing invalid multipart names
\dA regression.heap
improper qualified name (too many dotted names): regression.heap
@@ -6236,6 +6260,12 @@ cross-database references are not implemented: nonesuch.public.func_deps_stat
improper qualified name (too many dotted names): regression.myevt
\dy nonesuch.myevt
improper qualified name (too many dotted names): nonesuch.myevt
+\dV host.regression.public.var
+improper qualified name (too many dotted names): host.regression.public.var
+\dV regression|mydb.public.var
+cross-database references are not implemented: regression|mydb.public.var
+\dV nonesuch.public.var
+cross-database references are not implemented: nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
List of access methods
@@ -6470,6 +6500,12 @@ List of schemas
------+-------+-------+---------+----------+------
(0 rows)
+\dV "no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
improper qualified name (too many dotted names): "no.such.schema"."no.such.access.method"
@@ -6639,6 +6675,12 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
List of tables
@@ -6772,6 +6814,12 @@ List of text search templates
--------+------+------------+-----------+--------------+-----
(0 rows)
+\dV regression."no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -6819,6 +6867,8 @@ cross-database references are not implemented: "no.such.database"."no.such.schem
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
+cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
CREATE ROLE regress_du_role1;
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
new file mode 100644
index 00000000000..c36660ce6d3
--- /dev/null
+++ b/src/test/regress/expected/session_variables.out
@@ -0,0 +1,433 @@
+CREATE ROLE regress_variable_owner;
+SET log_statement TO ddl;
+-- should be ok
+CREATE VARIABLE var1 AS int;
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+ERROR: session variable cannot be pseudo-type anyelement
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+NOTICE: session variable "var2" does not exist, skipping
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+NOTICE: session variable "var1" already exists, skipping
+-- should fail
+CREATE VARIABLE var1 AS int;
+ERROR: session variable "var1" already exists
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TABLE t1;
+ERROR: cannot drop table t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+ERROR: cannot alter table "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TABLE t1;
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TYPE t1;
+ERROR: cannot drop type t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+ERROR: cannot alter type "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TYPE t1;
+SET log_statement TO default;
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+CREATE VARIABLE var1 AS testvar_domain;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter domain "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS testvar_type;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter type "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+NOTICE: NORMAL: orig=t normal=f istemp=f type=session variable identity=public.var1 name={public,var1} args={}
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+ obj_description
+-----------------------
+ some variable comment
+(1 row)
+
+DROP VARIABLE var1;
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+ varname | descr | type | object_names | object_args | ident
+---------------+-----------------------------------------+------------------+--------------------------+-------------+--------------------------------------------------------------------
+ svartest_var1 | session variable vartest1.svartest_var1 | session variable | {vartest1,svartest_var1} | {} | ("session variable",vartest1,svartest_var1,vartest1.svartest_var1)
+ svartest_var1 | session variable vartest2.svartest_var1 | session variable | {vartest2,svartest_var1} | {} | ("session variable",vartest2,svartest_var1,vartest2.svartest_var1)
+(2 rows)
+
+DROP SCHEMA vartest1 CASCADE;
+NOTICE: drop cascades to session variable vartest1.svartest_var1
+DROP SCHEMA vartest2 CASCADE;
+NOTICE: drop cascades to session variable vartest2.svartest_var1
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE ROLE regress_variable_reader;
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+DROP VARIABLE public.varxx;
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE public.var1 AS int;
+SET search_path TO public;
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+SET ROLE TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+--
+-- end of function has_session_variable_privilege tests.
+--
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+DROP VARIABLE public.var1;
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+DROP ROLE regress_variable_owner;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index e63ee2cf2bb..7aad3ad5d23 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -111,7 +111,7 @@ test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath sqljson
# NB: temp.sql does a reconnect which transiently uses 2 connections,
# so keep this parallel group to at most 19 tests
# ----------
-test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml
+test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml session_variables
# ----------
# Another group of parallel tests
diff --git a/src/test/regress/sql/dependency.sql b/src/test/regress/sql/dependency.sql
index 8d74ed7122c..6c18b7f840a 100644
--- a/src/test/regress/sql/dependency.sql
+++ b/src/test/regress/sql/dependency.sql
@@ -114,3 +114,17 @@ DROP USER regress_dep_user2;
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+
+-- should fail
+DROP DOMAIN vardomain;
+DROP TYPE vartype;
+
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index c58308ce14f..29d8caa7bac 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -1636,6 +1636,19 @@ COMMIT;
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+DROP VARIABLE var1;
+
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
+
-- check describing invalid multipart names
\dA regression.heap
\dA nonesuch.heap
@@ -1747,6 +1760,9 @@ DROP FUNCTION psql_error;
\dX nonesuch.public.func_deps_stat
\dy regression.myevt
\dy nonesuch.myevt
+\dV host.regression.public.var
+\dV regression|mydb.public.var
+\dV nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
@@ -1788,6 +1804,8 @@ DROP FUNCTION psql_error;
\dx "no.such.installed.extension"
\dX "no.such.extended.statistics"
\dy "no.such.event.trigger"
+\dV "no.such.variable"
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
@@ -1828,6 +1846,7 @@ DROP FUNCTION psql_error;
\dx "no.such.schema"."no.such.installed.extension"
\dX "no.such.schema"."no.such.extended.statistics"
\dy "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
@@ -1852,6 +1871,7 @@ DROP FUNCTION psql_error;
\dP regression."no.such.schema"."no.such.partitioned.relation"
\dT regression."no.such.schema"."no.such.data.type"
\dX regression."no.such.schema"."no.such.extended.statistics"
+\dV regression."no.such.schema"."no.such.variable"
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -1877,6 +1897,7 @@ DROP FUNCTION psql_error;
\dP "no.such.database"."no.such.schema"."no.such.partitioned.relation"
\dT "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
new file mode 100644
index 00000000000..eeb0f94ca3c
--- /dev/null
+++ b/src/test/regress/sql/session_variables.sql
@@ -0,0 +1,297 @@
+CREATE ROLE regress_variable_owner;
+
+SET log_statement TO ddl;
+
+-- should be ok
+CREATE VARIABLE var1 AS int;
+
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+
+-- should fail
+CREATE VARIABLE var1 AS int;
+
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TABLE t1;
+
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TABLE t1;
+
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TYPE t1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+SET log_statement TO default;
+
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+
+CREATE VARIABLE var1 AS testvar_domain;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+CREATE VARIABLE var1 AS testvar_type;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+
+DROP VARIABLE var1;
+
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+
+DROP SCHEMA vartest1 CASCADE;
+DROP SCHEMA vartest2 CASCADE;
+
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+
+CREATE ROLE regress_variable_reader;
+
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+
+DROP VARIABLE public.varxx;
+
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE public.var1 AS int;
+
+SET search_path TO public;
+
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+
+SET ROLE TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+--
+-- end of function has_session_variable_privilege tests.
+--
+
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+
+DROP VARIABLE public.var1;
+
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+
+DROP ROLE regress_variable_owner;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b6c170ac249..b2844730f79 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -540,6 +540,7 @@ CreateRoleStmt
CreateSchemaStmt
CreateSchemaStmtContext
CreateSeqStmt
+CreateSessionVarStmt
CreateStatsStmt
CreateStmt
CreateStmtContext
@@ -880,6 +881,7 @@ FormData_pg_ts_parser
FormData_pg_ts_template
FormData_pg_type
FormData_pg_user_mapping
+FormData_pg_variable
FormExtraData_pg_attribute
Form_pg_aggregate
Form_pg_am
@@ -939,6 +941,7 @@ Form_pg_ts_parser
Form_pg_ts_template
Form_pg_type
Form_pg_user_mapping
+Form_pg_variable
FormatNode
FreeBlockNumberArray
FreeListData
@@ -3102,6 +3105,7 @@ VarString
VarStringSortSupport
Variable
VariableAssignHook
+VariableInfo
VariableSetKind
VariableSetStmt
VariableShowStmt
--
2.48.1
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-02-20 20:22 ` Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Pavel Stehule @ 2025-02-20 20:22 UTC (permalink / raw)
To: jian he <[email protected]>; +Cc: Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
Hi
forced rebase
Regards
Pavel
Attachments:
[text/x-patch] v20250220-0021-pg_restore-A-variable.patch (2.8K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/3-v20250220-0021-pg_restore-A-variable.patch)
download | inline diff:
From 88dac788c9d45cb5299391657a744f481dcfe5ef Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sun, 21 Jul 2024 17:04:41 +0200
Subject: [PATCH 21/21] pg_restore -A, --variable
possibility to restore session variable specified by name
---
doc/src/sgml/ref/pg_restore.sgml | 11 +++++++++++
src/bin/pg_dump/pg_restore.c | 9 ++++++++-
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/doc/src/sgml/ref/pg_restore.sgml b/doc/src/sgml/ref/pg_restore.sgml
index b4031708430..7c3de311066 100644
--- a/doc/src/sgml/ref/pg_restore.sgml
+++ b/doc/src/sgml/ref/pg_restore.sgml
@@ -106,6 +106,17 @@ PostgreSQL documentation
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>-A <replaceable class="parameter">session_variable</replaceable></option></term>
+ <term><option>--variable=<replaceable class="parameter">session_variable</replaceable></option></term>
+ <listitem>
+ <para>
+ Restore a named session variable only. Multiple session variables may
+ be specified with multiple <option>-A</option> switches.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>-c</option></term>
<term><option>--clean</option></term>
diff --git a/src/bin/pg_dump/pg_restore.c b/src/bin/pg_dump/pg_restore.c
index 13e4dc507e0..60f01b23dba 100644
--- a/src/bin/pg_dump/pg_restore.c
+++ b/src/bin/pg_dump/pg_restore.c
@@ -110,6 +110,7 @@ main(int argc, char **argv)
{"trigger", 1, NULL, 'T'},
{"use-list", 1, NULL, 'L'},
{"username", 1, NULL, 'U'},
+ {"variable", 1, NULL, 'A'},
{"verbose", 0, NULL, 'v'},
{"single-transaction", 0, NULL, '1'},
@@ -164,7 +165,7 @@ main(int argc, char **argv)
}
}
- while ((c = getopt_long(argc, argv, "acCd:ef:F:h:I:j:lL:n:N:Op:P:RsS:t:T:U:vwWx1",
+ while ((c = getopt_long(argc, argv, "A:acCd:ef:F:h:I:j:lL:n:N:Op:P:RsS:t:T:U:vwWx1",
cmdopts, NULL)) != -1)
{
switch (c)
@@ -172,6 +173,11 @@ main(int argc, char **argv)
case 'a': /* Dump data only */
data_only = true;
break;
+ case 'A': /* vAriable */
+ opts->selTypes = 1;
+ opts->selVariable = 1;
+ simple_string_list_append(&opts->variableNames, optarg);
+ break;
case 'c': /* clean (i.e., drop) schema prior to create */
opts->dropSchema = 1;
break;
@@ -479,6 +485,7 @@ usage(const char *progname)
printf(_("\nOptions controlling the restore:\n"));
printf(_(" -a, --data-only restore only the data, no schema\n"));
+ printf(_(" -A, --variable=NAME restore named session variable\n"));
printf(_(" -c, --clean clean (drop) database objects before recreating\n"));
printf(_(" -C, --create create the target database\n"));
printf(_(" -e, --exit-on-error exit on error, default is to continue\n"));
--
2.48.1
[text/x-patch] v20250220-0020-transactional-variables.patch (37.3K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/4-v20250220-0020-transactional-variables.patch)
download | inline diff:
From 53ee03161a2c51799a866aea8c73c1df7a911b20 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:11:33 +0100
Subject: [PATCH 20/21] transactional variables
This commit implements transactional variables. The content of transactional
session variables is sensitive to transactions and subtransactions. Any
transactional variable holds a history of values necessary for revert. This history
is cleaned (purged) when a) we read the variable, b) when the transaction is finished.
We don't try to purge, when the last modification of a variable is from
current subtransaction, or when purge was processed in current subtransaction.
This patch is based on my work from Feb 2020 and it is related to discussion
about features related to session variables. Now, when the all features are
separated to isolated patches I can revitalize this patch, because it doesn't
increase complexity of basic patches.
Unlike other patches, this patch is without any review at this moment (Feb 2024),
but the feature should be fully functional for people who are interested about
this feature (for testing).
---
doc/src/sgml/catalogs.sgml | 12 +
doc/src/sgml/ref/create_variable.sgml | 10 +-
src/backend/catalog/pg_variable.c | 4 +
src/backend/commands/session_variable.c | 301 +++++++++++++++++-
src/backend/parser/gram.y | 50 +--
src/bin/pg_dump/pg_dump.c | 10 +-
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_dump/t/002_pg_dump.pl | 36 +++
src/bin/psql/describe.c | 4 +-
src/bin/psql/tab-complete.in.c | 5 +
src/include/catalog/pg_variable.h | 3 +
src/include/nodes/parsenodes.h | 1 +
src/include/parser/kwlist.h | 1 +
src/test/regress/expected/psql.out | 36 +--
.../regress/expected/session_variables.out | 100 ++++++
src/test/regress/sql/session_variables.sql | 58 ++++
16 files changed, 587 insertions(+), 45 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index c7a8170ddf2..1217f8f8647 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9884,6 +9884,18 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry><structfield>varistransact</structfield></entry>
+ <entry><type>boolean</type></entry>
+ <entry></entry>
+ <entry>
+ True, when the variable is <quote>transactional</quote>. In the case
+ of a transaction rollback, transactional variables are reset to the
+ value they had when the transaction started. The default value is
+ <literal>false</literal>.
+ </entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>vareoxaction</structfield> <type>char</type>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index 3c3e6d55b69..1aadd3677e5 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -26,7 +26,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-CREATE [ { TEMPORARY | TEMP } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+CREATE [ { TEMPORARY | TEMP } ] [ { TRANSACTIONAL | TRANSACTION } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
[ NOT NULL ] [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
@@ -47,6 +47,14 @@ CREATE [ { TEMPORARY | TEMP } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replac
same as regular variables in procedural languages.
</para>
+ <para>
+ When a schema variable is created with a
+ <command>CREATE TRANSACTIONAL VARIABLE</command> command, the variables
+ content changes are transactional: in case of rollback, they are reset to
+ their value at the beginning of the transaction or the latest subtransaction.
+ The variable content is only hold in memory, and thus is not persistent.
+ </para>
+
<para>
Session variables are retrieved by the <command>SELECT</command>
command. Their value is set with the <command>LET</command> command.
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 0b6093a00ba..fa49e7233d5 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -42,6 +42,7 @@ static ObjectAddress create_variable(const char *varName,
bool if_not_exists,
bool not_null,
bool is_immutable,
+ bool is_transact,
Node *varDefexpr,
VariableXactEndAction varXactEndAction);
@@ -59,6 +60,7 @@ create_variable(const char *varName,
bool if_not_exists,
bool not_null,
bool is_immutable,
+ bool is_transact,
Node *varDefexpr,
VariableXactEndAction varXactEndAction)
{
@@ -123,6 +125,7 @@ create_variable(const char *varName,
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
values[Anum_pg_variable_varnotnull - 1] = BoolGetDatum(not_null);
values[Anum_pg_variable_varisimmutable - 1] = BoolGetDatum(is_immutable);
+ values[Anum_pg_variable_varistransact - 1] = BoolGetDatum(is_transact);
values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
if (varDefexpr)
@@ -267,6 +270,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
stmt->if_not_exists,
stmt->not_null,
stmt->is_immutable,
+ stmt->is_transact,
cooked_default,
stmt->XactEndAction);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index b08c1b47d38..5ac488795a1 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -47,6 +47,19 @@ typedef struct SVariableXActDropItem
SubTransactionId deleting_subid;
} SVariableXActDropItem;
+/*
+ * Used for transactional variables. Holds prev version.
+ */
+typedef struct PrevValue
+{
+ Datum value;
+ bool isnull;
+
+ SubTransactionId modify_subid;
+
+ struct PrevValue *prev_value;
+} PrevValue;
+
/*
* The values of session variables are stored in the backend's private memory
* in the dedicated memory context SVariableMemoryContext in binary format.
@@ -68,6 +81,25 @@ typedef struct SVariableData
bool isnull;
Datum value;
+ /*
+ * We don't need stack versions modified in same subtransaction.
+ * Used by transactional variables only. The value of transactional
+ * variable can be returned immediately when modify_subid is same
+ * like current subid.
+ */
+ SubTransactionId modify_subid;
+
+ /*
+ * When the modify_subid is different than current subid, then
+ * we need to recheck versions and throw versions related to
+ * reverted transactions. When purge_subid is same like current subid
+ * we can return the value of transaction variable without this
+ * recheck.
+ */
+ SubTransactionId purge_subid;
+
+ PrevValue *prev_value;
+
Oid typid;
int16 typlen;
bool typbyval;
@@ -86,6 +118,7 @@ typedef struct SVariableData
bool not_null;
bool is_immutable;
+ bool is_transact;
bool reset_at_eox;
@@ -125,6 +158,9 @@ static bool needs_validation = false;
*/
static bool has_session_variables_with_reset_at_eox = false;
+/* true, when transactional variables was modified */
+static bool has_modified_transactional_variables = false;
+
/*
* The content of dropped session variables is not removed immediately. If
* possible, we do that at the end of the transaction. But we cannot do that
@@ -140,6 +176,7 @@ static List *xact_drop_items = NIL;
static void register_session_variable_xact_drop(Oid varid);
static void unregister_session_variable_xact_drop(Oid varid);
+static bool purge_session_variable(SVariable svar);
/*
* Callback function for session variable invalidation.
@@ -292,8 +329,25 @@ unregister_session_variable_xact_drop(Oid varid)
* Release stored value, free memory
*/
static void
-free_session_variable_value(SVariable svar)
+free_session_variable_value(SVariable svar, bool deep_free)
{
+ if (deep_free)
+ {
+ PrevValue *prev_value = svar->prev_value;
+ PrevValue *next_value;
+
+ while (prev_value)
+ {
+ if (!svar->typbyval)
+ pfree(DatumGetPointer(prev_value->value));
+
+ next_value = prev_value->prev_value;
+ pfree(prev_value);
+
+ prev_value = next_value;
+ }
+ }
+
/* clean the current value */
if (!svar->isnull)
{
@@ -390,7 +444,7 @@ remove_invalid_session_variables(bool atEOX)
{
Oid varid = svar->varid;
- free_session_variable_value(svar);
+ free_session_variable_value(svar, true);
hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
svar = NULL;
}
@@ -426,6 +480,94 @@ remove_session_variables_with_reset_at_eox(void)
has_session_variables_with_reset_at_eox = false;
}
+/*
+ * remove prev values at eox
+ */
+static void
+remove_prev_values_at_eox(bool isCommit)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ if (!sessionvars)
+ return;
+
+ /* leave quckly, when there are not that variables */
+ if (!has_modified_transactional_variables)
+ return;
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (svar->is_transact && svar->modify_subid != InvalidSubTransactionId)
+ {
+ if (isCommit)
+ {
+ if (purge_session_variable(svar))
+ {
+ PrevValue *prev_value = svar->prev_value;
+
+ while (prev_value)
+ {
+ PrevValue *current_pv = prev_value;
+
+ if (!svar->typbyval && !current_pv->isnull)
+ pfree(DatumGetPointer(current_pv->value));
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+ }
+ }
+ else
+ {
+ hash_search(sessionvars, &svar->varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ }
+ else
+ {
+ PrevValue *prev_value = svar->prev_value;
+
+ while (prev_value)
+ {
+ PrevValue *current_pv = prev_value;
+
+ if (current_pv->modify_subid == InvalidSubTransactionId)
+ break;
+
+ if (!svar->typbyval && !current_pv->isnull)
+ pfree(DatumGetPointer(current_pv->value));
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+ }
+
+ if (prev_value)
+ {
+ svar->value = prev_value->value;
+ svar->isnull = prev_value->isnull;
+
+ pfree(prev_value);
+ }
+ else
+ {
+ hash_search(sessionvars, &svar->varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ }
+
+ /* when svar is still valid (not removed from sessionvars */
+ if (svar)
+ {
+ svar->modify_subid = InvalidSubTransactionId;
+ svar->prev_value = NULL;
+ }
+ }
+ }
+
+ has_modified_transactional_variables = false;
+}
+
/*
* Perform ON COMMIT DROP for temporary session variables,
* and remove all dropped variables from memory.
@@ -473,6 +615,8 @@ AtPreEOXact_SessionVariables(bool isCommit)
remove_invalid_session_variables(true);
}
+ remove_prev_values_at_eox(isCommit);
+
/*
* We have to clean xact_drop_items. All related variables are dropped
* now, or lost inside aborted transaction.
@@ -618,6 +762,7 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
svar->not_null = varform->varnotnull;
svar->is_immutable = varform->varisimmutable;
+ svar->is_transact = varform->varistransact;
svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
svar->domain_check_extra = NULL;
@@ -643,6 +788,17 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
svar->isnull = true;
svar->value = (Datum) 0;
+ if (svar->is_transact)
+ {
+ svar->modify_subid = GetCurrentSubTransactionId();
+ has_modified_transactional_variables = true;
+ }
+ else
+ svar->modify_subid = InvalidSubTransactionId;
+
+ svar->purge_subid = InvalidSubTransactionId;
+ svar->prev_value = NULL;
+
svar->is_valid = true;
svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
@@ -676,6 +832,69 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
ReleaseSysCache(tup);
}
+/*
+ * Try to remove all previous versions related to reverted transactions.
+ * Returns true, when valid version was found.
+ */
+static bool
+purge_session_variable(SVariable svar)
+{
+ SubTransactionId current_subid;
+ PrevValue *prev_value;
+ bool found = true;
+
+ Assert(svar->is_transact);
+
+ if (svar->modify_subid == InvalidSubTransactionId)
+ return true;
+
+ current_subid = GetCurrentSubTransactionId();
+
+ if (svar->modify_subid == current_subid)
+ return true;
+
+ if (svar->purge_subid == current_subid)
+ return true;
+
+ if (SubTransactionIsActive(svar->modify_subid))
+ {
+ svar->purge_subid = current_subid;
+ return true;
+ }
+
+ prev_value = svar->prev_value;
+
+ while (prev_value)
+ {
+ PrevValue *current_pv = prev_value;
+
+ if (current_pv->modify_subid == InvalidSubTransactionId ||
+ SubTransactionIsActive(current_pv->modify_subid))
+ {
+ svar->value = current_pv->value;
+ svar->isnull = current_pv->isnull;
+ svar->modify_subid = current_pv->modify_subid;
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+
+ found = true;
+ break;
+ }
+
+ if (!svar->typbyval && !current_pv->isnull)
+ pfree(DatumGetPointer(current_pv->value));
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+ }
+
+ svar->prev_value = prev_value;
+ svar->purge_subid = current_subid;
+
+ return found;
+}
+
/*
* Assign a new value to the session variable. It is copied to
* SVariableMemoryContext if necessary.
@@ -688,6 +907,10 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
Datum newval;
SVariableData locsvar,
*_svar;
+ SubTransactionId current_subid = GetCurrentSubTransactionId();
+ SubTransactionId prev_purge_subid = InvalidSubTransactionId;
+ bool save_prev_value;
+ PrevValue *prev_value;
Assert(svar);
Assert(!isnull || value == (Datum) 0);
@@ -723,6 +946,21 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
else
_svar = svar;
+ if (_svar->is_transact && _svar->create_lsn == svar->create_lsn)
+ {
+ Assert(svar->typid == _svar->typid);
+ Assert(svar->typbyval == _svar->typbyval);
+ Assert(svar->typlen == _svar->typlen);
+
+ save_prev_value = svar->modify_subid != current_subid;
+ prev_value = svar->prev_value;
+ }
+ else
+ {
+ save_prev_value = false;
+ prev_value = NULL;
+ }
+
if (!isnull)
{
MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
@@ -734,7 +972,37 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
else
newval = value;
- free_session_variable_value(svar);
+ if (save_prev_value)
+ {
+ volatile PrevValue *new_prev_value;
+
+ PG_TRY();
+ {
+ new_prev_value = MemoryContextAlloc(SVariableMemoryContext,
+ sizeof(PrevValue));
+ }
+ PG_CATCH();
+ {
+ /* release mem from persistent content */
+ if (newval != value)
+ pfree(DatumGetPointer(newval));
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
+
+ new_prev_value->value = svar->value;
+ new_prev_value->isnull = svar->isnull;
+ new_prev_value->modify_subid = svar->modify_subid;
+ new_prev_value->prev_value = prev_value;
+
+ prev_value = (PrevValue *) new_prev_value;
+ prev_purge_subid = svar->purge_subid;
+
+ has_modified_transactional_variables = true;
+
+ }
+ else
+ free_session_variable_value(svar, prev_value == NULL);
elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value",
get_namespace_name(get_session_variable_namespace(svar->varid)),
@@ -747,6 +1015,9 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
svar->value = newval;
svar->isnull = isnull;
+ svar->modify_subid = current_subid;
+ svar->purge_subid = prev_purge_subid;
+ svar->prev_value = prev_value;
/* don't allow more changes of value when variable is IMMUTABLE */
if (svar->is_immutable)
@@ -848,6 +1119,8 @@ get_session_variable(Oid varid)
else
svar->is_valid = false;
+reinit:
+
/*
* Force setup for not yet initialized variables or variables that cannot
* be validated.
@@ -880,6 +1153,28 @@ get_session_variable(Oid varid)
varid);
}
+ /*
+ * Transactional variables should be purged before (remove
+ * versions created by possibly reverted subtransactions).
+ */
+ if (svar->is_transact &&
+ svar->modify_subid != GetCurrentSubTransactionId() &&
+ svar->modify_subid != InvalidSubTransactionId)
+ {
+ if (!purge_session_variable(svar))
+ {
+ /* force reinit */
+ svar->is_valid = false;
+
+ /*
+ * In next iteration modify_subid should be
+ * InvalidSubTransactionId or current subid,
+ * so there is not risk of infinity cycle.
+ */
+ goto reinit;
+ }
+ }
+
/* ensure the returned data is still of the correct domain */
if (svar->is_domain)
{
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 1c96bbf0819..bc5302f0fcf 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -675,7 +675,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
json_object_constructor_null_clause_opt
json_array_constructor_null_clause_opt
-%type <boolean> OptNotNull OptImmutable
+%type <boolean> OptNotNull OptImmutable OptTransactional
/*
* Non-keyword token types. These are hard-wired into the "flex" lexer.
@@ -780,7 +780,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
SUBSCRIPTION SUBSTRING SUPPORT SYMMETRIC SYSID SYSTEM_P SYSTEM_USER
TABLE TABLES TABLESAMPLE TABLESPACE TARGET TEMP TEMPLATE TEMPORARY TEXT_P THEN
- TIES TIME TIMESTAMP TO TRAILING TRANSACTION TRANSFORM
+ TIES TIME TIMESTAMP TO TRAILING TRANSACTION TRANSACTIONAL TRANSFORM
TREAT TRIGGER TRIM TRUE_P
TRUNCATE TRUSTED TYPE_P TYPES_P
@@ -5274,31 +5274,33 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE OptTemp OptImmutable VARIABLE qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
+ CREATE OptTemp OptTransactional OptImmutable VARIABLE qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $5->relpersistence = $2;
- n->is_immutable = $3;
- n->variable = $5;
- n->typeName = $7;
- n->collClause = (CollateClause *) $8;
- n->not_null = $9;
- n->defexpr = $10;
- n->XactEndAction = $11;
+ $6->relpersistence = $2;
+ n->is_immutable = $4;
+ n->is_transact = $3;
+ n->variable = $6;
+ n->typeName = $8;
+ n->collClause = (CollateClause *) $9;
+ n->not_null = $10;
+ n->defexpr = $11;
+ n->XactEndAction = $12;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE OptTemp OptImmutable VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
+ | CREATE OptTemp OptTransactional OptImmutable VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $8->relpersistence = $2;
- n->is_immutable = $3;
- n->variable = $8;
- n->typeName = $10;
- n->collClause = (CollateClause *) $11;
- n->not_null = $12;
- n->defexpr = $13;
- n->XactEndAction = $14;
+ $9->relpersistence = $2;
+ n->is_immutable = $4;
+ n->is_transact = $3;
+ n->variable = $9;
+ n->typeName = $11;
+ n->collClause = (CollateClause *) $12;
+ n->not_null = $13;
+ n->defexpr = $14;
+ n->XactEndAction = $15;
n->if_not_exists = true;
$$ = (Node *) n;
}
@@ -5326,6 +5328,12 @@ OptImmutable: IMMUTABLE { $$ = true; }
| /* EMPTY */ { $$ = false; }
;
+OptTransactional:
+ TRANSACTION { $$ = true; }
+ | TRANSACTIONAL { $$ = true; }
+ | /* EMPTY */ { $$ = false; }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
@@ -18174,6 +18182,7 @@ unreserved_keyword:
| TEXT_P
| TIES
| TRANSACTION
+ | TRANSACTIONAL
| TRANSFORM
| TRIGGER
| TRUNCATE
@@ -18824,6 +18833,7 @@ bare_label_keyword:
| TIMESTAMP
| TRAILING
| TRANSACTION
+ | TRANSACTIONAL
| TRANSFORM
| TREAT
| TRIGGER
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index bc86e7a0fa9..2f74a88067b 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5473,6 +5473,7 @@ getVariables(Archive *fout)
int i_varcollation;
int i_varnotnull;
int i_varisimmutable;
+ int i_varistransact;
int i_varacl;
int i_acldefault;
int i,
@@ -5495,6 +5496,7 @@ getVariables(Archive *fout)
" END AS varcollation,\n"
" v.varnotnull,\n"
" v.varisimmutable,\n"
+ " v.varistransact,\n"
" pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n"
" v.varowner, v.varacl,\n"
" acldefault('V', v.varowner) AS acldefault\n"
@@ -5517,6 +5519,7 @@ getVariables(Archive *fout)
i_varcollation = PQfnumber(res, "varcollation");
i_varnotnull = PQfnumber(res, "varnotnull");
i_varisimmutable = PQfnumber(res, "varisimmutable");
+ i_varistransact = PQfnumber(res, "varistransact");
i_varowner = PQfnumber(res, "varowner");
i_varacl = PQfnumber(res, "varacl");
@@ -5545,6 +5548,7 @@ getVariables(Archive *fout)
varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
varinfo[i].varnotnull = *(PQgetvalue(res, i, i_varnotnull)) == 't';
varinfo[i].varisimmutable = *(PQgetvalue(res, i, i_varisimmutable)) == 't';
+ varinfo[i].varistransact = *(PQgetvalue(res, i, i_varistransact)) == 't';
varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
@@ -5592,6 +5596,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
const char *vardefexpr;
const char *varxactendaction;
const char *varisimmutable;
+ const char *varistransact;
Oid varcollation;
bool varnotnull;
@@ -5609,12 +5614,13 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
varcollation = varinfo->varcollation;
varnotnull = varinfo->varnotnull;
varisimmutable = varinfo->varisimmutable ? "IMMUTABLE " : "";
+ varistransact = varinfo->varistransact ? "TRANSACTIONAL " : "";
appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
qualvarname);
- appendPQExpBuffer(query, "CREATE %sVARIABLE %s AS %s",
- varisimmutable, qualvarname, vartypname);
+ appendPQExpBuffer(query, "CREATE %s%sVARIABLE %s AS %s",
+ varistransact, varisimmutable, qualvarname, vartypname);
if (OidIsValid(varcollation))
{
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index dad3a74c7d3..3d4e726c4cf 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -736,6 +736,7 @@ typedef struct _VariableInfo
const char *rolname; /* name of owner, or empty string */
bool varnotnull;
bool varisimmutable;
+ bool varistransact;
} VariableInfo;
/*
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index ecf37dbe6fb..28958b316a1 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4201,6 +4201,42 @@ my %tests = (
},
},
+ 'CREATE TRANSACTIONAL VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE TRANSACTIONAL VARIABLE dump_test.variable8 AS integer',
+ regexp => qr/^
+ \QCREATE TRANSACTIONAL VARIABLE dump_test.variable8 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
+ 'CREATE TRANSACTIONAL IMMUTABLE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE TRANSACTIONAL IMMUTABLE VARIABLE dump_test.variable9 AS integer',
+ regexp => qr/^
+ \QCREATE TRANSACTIONAL IMMUTABLE VARIABLE dump_test.variable9 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 503ae160398..f7c1e414485 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5354,6 +5354,7 @@ listVariables(const char *pattern, bool verbose)
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
" NOT v.varnotnull as \"%s\",\n"
" NOT v.varisimmutable as \"%s\",\n"
+ " v.varistransact as \"%s\",\n"
" pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
@@ -5366,6 +5367,7 @@ listVariables(const char *pattern, bool verbose)
gettext_noop("Owner"),
gettext_noop("Nullable"),
gettext_noop("Mutable"),
+ gettext_noop("Transactional"),
gettext_noop("Default"),
gettext_noop("Transactional end action"));
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index eee0216f396..4141104f258 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1319,6 +1319,8 @@ static const pgsql_thing_t words_after_create[] = {
* TABLE ... */
{"TEXT SEARCH", NULL, NULL, NULL},
{"TRANSFORM", NULL, NULL, NULL, NULL, THING_NO_ALTER},
+ {"TRANSACTIONAL", NULL, NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE TRANSACTIONAL
+ * VARIABLE ... */
{"TRIGGER", "SELECT tgname FROM pg_catalog.pg_trigger WHERE tgname LIKE '%s' AND NOT tgisinternal"},
{"TYPE", NULL, NULL, &Query_for_list_of_datatypes},
{"UNIQUE", NULL, NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE UNIQUE
@@ -3991,8 +3993,11 @@ match_previous_words(int pattern_id,
}
/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE VARIABLE <name> with AS */
+ else if (Matches("CREATE", "TRANSACTION|TRANSACTIONAL"))
+ COMPLETE_WITH("IMMUTABLE", "VARIABLE");
else if (TailMatches("CREATE", "VARIABLE", MatchAny) ||
TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny) ||
+ TailMatches("TRANSACTION|TRANSACTIONAL", "VARIABLE", MatchAny) ||
TailMatches("IMMUTABLE", "VARIABLE", MatchAny))
COMPLETE_WITH("AS");
else if (TailMatches("VARIABLE", MatchAny, "AS"))
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index cf21e0426a7..454bb297097 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -62,6 +62,9 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* don't allow changes */
bool varisimmutable BKI_DEFAULT(f);
+ /* supports transactions */
+ bool varistransact BKI_DEFAULT(f);
+
/* action on transaction end */
char varxactendaction BKI_DEFAULT(n);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 8d0d7cf6ec9..e02b7c0a31c 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3550,6 +3550,7 @@ typedef struct CreateSessionVarStmt
bool if_not_exists; /* do nothing if it already exists */
bool not_null; /* disallow nulls */
bool is_immutable; /* don't allow changes */
+ bool is_transact; /* supports transactions */
Node *defexpr; /* default expression */
char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 431167f6b43..e19b957739f 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -456,6 +456,7 @@ PG_KEYWORD("timestamp", TIMESTAMP, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("to", TO, RESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("trailing", TRAILING, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("transaction", TRANSACTION, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("transactional", TRANSACTIONAL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("transform", TRANSFORM, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("treat", TREAT, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("trigger", TRIGGER, UNRESERVED_KEYWORD, BARE_LABEL)
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index ec870172faa..061307621cd 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6020,20 +6020,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | t | t | | | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------------+---------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | f | | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | t | t | | | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------------+---------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | f | | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6501,9 +6501,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
---------+------+------+-----------+-------+----------+---------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------------+---------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6676,9 +6676,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
---------+------+------+-----------+-------+----------+---------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------------+---------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6815,9 +6815,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
---------+------+------+-----------+-------+----------+---------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------------+---------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7b71bba90e9..9059e6bc249 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2502,3 +2502,103 @@ SELECT var1;
LET var1 = 30;
ERROR: session variable "public.var1" is declared IMMUTABLE
DROP VARIABLE var1;
+-- test transactional variables
+CREATE TRANSACTION VARIABLE tv AS int DEFAULT 0;
+BEGIN;
+ LET tv = 100;
+ SELECT tv;
+ tv
+-----
+ 100
+(1 row)
+
+ROLLBACK;
+SELECT tv;
+ tv
+----
+ 0
+(1 row)
+
+LET tv = 100;
+BEGIN;
+ LET tv = 1000;
+COMMIT;
+SELECT tv;
+ tv
+------
+ 1000
+(1 row)
+
+BEGIN;
+ LET tv = 0;
+ SELECT tv;
+ tv
+----
+ 0
+(1 row)
+
+ROLLBACK;
+SELECT tv;
+ tv
+------
+ 1000
+(1 row)
+
+-- test subtransactions
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ tv
+----
+ 2
+(1 row)
+
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+ tv
+----
+ 1
+(1 row)
+
+ROLLBACK;
+SELECT tv;
+ tv
+------
+ 1000
+(1 row)
+
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ tv
+----
+ 2
+(1 row)
+
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+ tv
+----
+ 1
+(1 row)
+
+COMMIT;
+SELECT tv;
+ tv
+----
+ 1
+(1 row)
+
+DROP VARIABLE tv;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index c8c2295adbd..880f60e9917 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1735,3 +1735,61 @@ SELECT var1;
LET var1 = 30;
DROP VARIABLE var1;
+
+-- test transactional variables
+CREATE TRANSACTION VARIABLE tv AS int DEFAULT 0;
+
+BEGIN;
+ LET tv = 100;
+ SELECT tv;
+ROLLBACK;
+
+SELECT tv;
+
+LET tv = 100;
+BEGIN;
+ LET tv = 1000;
+COMMIT;
+
+SELECT tv;
+
+BEGIN;
+ LET tv = 0;
+ SELECT tv;
+ROLLBACK;
+
+SELECT tv;
+
+-- test subtransactions
+
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+ROLLBACK;
+
+SELECT tv;
+
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+COMMIT;
+
+SELECT tv;
+
+DROP VARIABLE tv;
--
2.48.1
[text/x-patch] v20250220-0017-plpgsql-implementation-for-LET-statement.patch (16.8K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/5-v20250220-0017-plpgsql-implementation-for-LET-statement.patch)
download | inline diff:
From 19a1be46e9e82680accbb6eb919048be30c399e6 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sat, 20 Jan 2024 08:56:17 +0100
Subject: [PATCH 17/21] plpgsql implementation for LET statement
PLpgSQL allows to call expression executor directly (for simple expression).
This possibility strongly reduces overhead related to execution. Reimplementation
of LET statement (inside PLpgSQL) allows to use this possibility, and strongly
increase performance:
CREATE VARIABLE svar int;
DO $$
BEGIN
FOR i IN 1..10000
LOOP
LET svar = i;
END LOOP;
END;
$$;
From 120ms to 8ms (with assertions) (this is best case, but without it, the LET statement
can be bottle neck).
An alternative can be reimplementation of LET statement inside expression
executor, and then SQL LET command can be executed in simple expression
execution, but this increase an complexity of executor, but still the
benefits is only inside plpgsql, so it is better to this optimization
inside plpgsql.
---
src/backend/commands/session_variable.c | 16 ++++++
src/backend/executor/spi.c | 3 +
src/backend/parser/analyze.c | 12 ++++
src/backend/parser/gram.y | 8 +++
src/backend/parser/parser.c | 1 +
src/include/commands/session_variable.h | 1 +
src/include/nodes/parsenodes.h | 2 +
src/include/parser/parser.h | 4 ++
src/pl/plpgsql/src/pl_exec.c | 56 +++++++++++++++++++
src/pl/plpgsql/src/pl_funcs.c | 21 +++++++
src/pl/plpgsql/src/pl_gram.y | 29 +++++++++-
src/pl/plpgsql/src/pl_reserved_kwlist.h | 1 +
src/pl/plpgsql/src/pl_unreserved_kwlist.h | 1 +
src/pl/plpgsql/src/plpgsql.h | 12 ++++
.../regress/expected/session_variables.out | 6 +-
src/tools/pgindent/typedefs.list | 1 +
16 files changed, 169 insertions(+), 5 deletions(-)
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index bb6abb792be..b08c1b47d38 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -948,6 +948,22 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
set_session_variable(svar, value, isNull);
}
+/*
+ * Wrapper around SetSessionVariable with permission checks.
+ */
+void
+SetSessionVariableWithSecurityCheck(Oid varid, Datum value, bool isNull)
+{
+ AclResult aclresult;
+
+ /* is the caller allowed to update the session variable? */
+ aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid));
+
+ SetSessionVariable(varid, value, isNull);
+}
+
/*
* Returns a copy of the value stored in a variable.
*/
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 3288396def3..e3c4d259d53 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -3008,6 +3008,9 @@ _SPI_error_callback(void *arg)
case RAW_PARSE_PLPGSQL_ASSIGN3:
errcontext("PL/pgSQL assignment \"%s\"", query);
break;
+ case RAW_PARSE_PLPGSQL_LET:
+ errcontext("LET statement \"%s\"", query);
+ break;
default:
errcontext("SQL statement \"%s\"", query);
break;
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 46a22ff5c94..2de0d23c8e3 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -2012,6 +2012,18 @@ transformLetStmt(ParseState *pstate, LetStmt *stmt)
stmt->query = (Node *) query;
+ /*
+ * Inside PL/pgSQL we don't want to execute LET statement as utility
+ * command, because it disallow to execute expression as simple
+ * expression. So for PL/pgSQL we have extra path, and we return SELECT.
+ * Then it can be executed by exec_eval_expr. Result is dirrectly assigned
+ * to target session variable inside PL/pgSQL LET statement handler. This
+ * is extra code, extra path, but possibility to get faster execution is
+ * too attractive.
+ */
+ if (stmt->plpgsql_mode)
+ return query;
+
/* represent the command as a utility Query */
result = makeNode(Query);
result->commandType = CMD_UTILITY;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 53284c0289c..1c96bbf0819 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -824,6 +824,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%token MODE_PLPGSQL_ASSIGN1
%token MODE_PLPGSQL_ASSIGN2
%token MODE_PLPGSQL_ASSIGN3
+%token MODE_PLPGSQL_LET
/* Precedence: lowest to highest */
@@ -955,6 +956,13 @@ parse_toplevel:
pg_yyget_extra(yyscanner)->parsetree =
list_make1(makeRawStmt((Node *) n, @2));
}
+ | MODE_PLPGSQL_LET LetStmt
+ {
+ LetStmt *n = (LetStmt *) $2;
+ n->plpgsql_mode = true;
+ pg_yyget_extra(yyscanner)->parsetree =
+ list_make1(makeRawStmt((Node *) n, 0));
+ }
;
/*
diff --git a/src/backend/parser/parser.c b/src/backend/parser/parser.c
index 33a040506b4..887212aefde 100644
--- a/src/backend/parser/parser.c
+++ b/src/backend/parser/parser.c
@@ -62,6 +62,7 @@ raw_parser(const char *str, RawParseMode mode)
[RAW_PARSE_PLPGSQL_ASSIGN1] = MODE_PLPGSQL_ASSIGN1,
[RAW_PARSE_PLPGSQL_ASSIGN2] = MODE_PLPGSQL_ASSIGN2,
[RAW_PARSE_PLPGSQL_ASSIGN3] = MODE_PLPGSQL_ASSIGN3,
+ [RAW_PARSE_PLPGSQL_LET] = MODE_PLPGSQL_LET,
};
yyextra.have_lookahead = true;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index f66b6c0b864..b89728ead5a 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -28,6 +28,7 @@ extern void AtEOSubXact_SessionVariables(bool isCommit, SubTransactionId mySubid
SubTransactionId parentSubid);
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
+extern void SetSessionVariableWithSecurityCheck(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
extern Datum GetSessionVariableWithTypeid(Oid varid, bool *isNull, Oid *typid);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 785354ab52c..8d0d7cf6ec9 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2168,6 +2168,8 @@ typedef struct LetStmt
NodeTag type;
List *target; /* target variable */
Node *query; /* source expression */
+ bool plpgsql_mode; /* true, when command will be executed
+ * (parsed) by plpgsql runtime */
ParseLoc location;
} LetStmt;
diff --git a/src/include/parser/parser.h b/src/include/parser/parser.h
index 350196cd641..c8d5e8dbf92 100644
--- a/src/include/parser/parser.h
+++ b/src/include/parser/parser.h
@@ -33,6 +33,9 @@
* RAW_PARSE_PLPGSQL_ASSIGNn: parse a PL/pgSQL assignment statement,
* and return a one-element List containing a RawStmt node. "n"
* gives the number of dotted names comprising the target ColumnRef.
+ *
+ * RAW_PARSE_PLPGSQL_LET: parse a LET statement, and return a
+ * one-element List containing a RawStmt node.
*/
typedef enum
{
@@ -42,6 +45,7 @@ typedef enum
RAW_PARSE_PLPGSQL_ASSIGN1,
RAW_PARSE_PLPGSQL_ASSIGN2,
RAW_PARSE_PLPGSQL_ASSIGN3,
+ RAW_PARSE_PLPGSQL_LET,
} RawParseMode;
/* Values for the backslash_quote GUC */
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index d4377ceecbf..05eb4ac4f32 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -22,6 +22,7 @@
#include "access/tupconvert.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "commands/session_variable.h"
#include "executor/execExpr.h"
#include "executor/spi.h"
#include "executor/tstoreReceiver.h"
@@ -333,6 +334,8 @@ static int exec_stmt_commit(PLpgSQL_execstate *estate,
PLpgSQL_stmt_commit *stmt);
static int exec_stmt_rollback(PLpgSQL_execstate *estate,
PLpgSQL_stmt_rollback *stmt);
+static int exec_stmt_let(PLpgSQL_execstate *estate,
+ PLpgSQL_stmt_let *let);
static void plpgsql_estate_setup(PLpgSQL_execstate *estate,
PLpgSQL_function *func,
@@ -2132,6 +2135,10 @@ exec_stmts(PLpgSQL_execstate *estate, List *stmts)
rc = exec_stmt_rollback(estate, (PLpgSQL_stmt_rollback *) stmt);
break;
+ case PLPGSQL_STMT_LET:
+ rc = exec_stmt_let(estate, (PLpgSQL_stmt_let *) stmt);
+ break;
+
default:
/* point err_stmt to parent, since this one seems corrupt */
estate->err_stmt = save_estmt;
@@ -5009,6 +5016,55 @@ exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt)
return PLPGSQL_RC_OK;
}
+/* ----------
+ * exec_stmt_let Evaluate an expression and
+ * put the result into a session variable.
+ * ----------
+ */
+static int
+exec_stmt_let(PLpgSQL_execstate *estate, PLpgSQL_stmt_let *stmt)
+{
+ bool isNull;
+ Oid valtype;
+ int32 valtypmod;
+ Datum value;
+ Oid varid;
+
+ List *plansources;
+ CachedPlanSource *plansource;
+
+ value = exec_eval_expr(estate,
+ stmt->expr,
+ &isNull,
+ &valtype,
+ &valtypmod);
+
+ /*
+ * Oid of target session variable is stored in Query structure. It is
+ * safer to read this value directly from the plan than to hold this value
+ * in the plpgsql context, because it's not necessary to handle
+ * invalidation of the cached value. Next operations are read only without
+ * any allocations, so we can expect that retrieving varid from Query
+ * should be fast.
+ */
+ plansources = SPI_plan_get_plan_sources(stmt->expr->plan);
+ if (list_length(plansources) != 1)
+ elog(ERROR, "unexpected length of plansources of query for LET statement");
+
+ plansource = (CachedPlanSource *) linitial(plansources);
+ if (list_length(plansource->query_list) != 1)
+ elog(ERROR, "unexpected length of plansource of query for LET statement");
+
+ varid = linitial_node(Query, plansource->query_list)->resultVariable;
+ if (!OidIsValid(varid))
+ elog(ERROR, "oid of target session variable is not valid");
+
+ SetSessionVariableWithSecurityCheck(varid, value, isNull);
+ exec_eval_cleanup(estate);
+
+ return PLPGSQL_RC_OK;
+}
+
/* ----------
* exec_assign_expr Put an expression's result into a variable.
* ----------
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index 6b5394fc5fa..242b57f76de 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -288,6 +288,8 @@ plpgsql_stmt_typename(PLpgSQL_stmt *stmt)
return "COMMIT";
case PLPGSQL_STMT_ROLLBACK:
return "ROLLBACK";
+ case PLPGSQL_STMT_LET:
+ return "LET";
}
return "unknown";
@@ -585,6 +587,13 @@ plpgsql_statement_tree_walker_impl(PLpgSQL_stmt *stmt,
E_WALK(cstmt->expr);
break;
}
+ case PLPGSQL_STMT_LET:
+ {
+ PLpgSQL_stmt_let *lstmt = (PLpgSQL_stmt_let *) stmt;
+
+ E_WALK(lstmt->expr);
+ break;
+ }
case PLPGSQL_STMT_COMMIT:
case PLPGSQL_STMT_ROLLBACK:
{
@@ -806,6 +815,7 @@ static void dump_perform(PLpgSQL_stmt_perform *stmt);
static void dump_call(PLpgSQL_stmt_call *stmt);
static void dump_commit(PLpgSQL_stmt_commit *stmt);
static void dump_rollback(PLpgSQL_stmt_rollback *stmt);
+static void dump_let(PLpgSQL_stmt_let *stmt);
static void dump_expr(PLpgSQL_expr *expr);
@@ -905,6 +915,9 @@ dump_stmt(PLpgSQL_stmt *stmt)
case PLPGSQL_STMT_ROLLBACK:
dump_rollback((PLpgSQL_stmt_rollback *) stmt);
break;
+ case PLPGSQL_STMT_LET:
+ dump_let((PLpgSQL_stmt_let *) stmt);
+ break;
default:
elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
break;
@@ -1581,6 +1594,14 @@ dump_getdiag(PLpgSQL_stmt_getdiag *stmt)
printf("\n");
}
+static void
+dump_let(PLpgSQL_stmt_let *stmt)
+{
+ dump_ind();
+ dump_expr(stmt->expr);
+ printf("\n");
+}
+
static void
dump_expr(PLpgSQL_expr *expr)
{
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index 8048e040f81..980ebb56a45 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -210,7 +210,7 @@ static void check_raise_parameters(PLpgSQL_stmt_raise *stmt);
%type <stmt> stmt_return stmt_raise stmt_assert stmt_execsql
%type <stmt> stmt_dynexecute stmt_for stmt_perform stmt_call stmt_getdiag
%type <stmt> stmt_open stmt_fetch stmt_move stmt_close stmt_null
-%type <stmt> stmt_commit stmt_rollback
+%type <stmt> stmt_commit stmt_rollback stmt_let
%type <stmt> stmt_case stmt_foreach_a
%type <list> proc_exceptions
@@ -317,6 +317,7 @@ static void check_raise_parameters(PLpgSQL_stmt_raise *stmt);
%token <keyword> K_INTO
%token <keyword> K_IS
%token <keyword> K_LAST
+%token <keyword> K_LET
%token <keyword> K_LOG
%token <keyword> K_LOOP
%token <keyword> K_MERGE
@@ -891,6 +892,8 @@ proc_stmt : pl_block ';'
{ $$ = $1; }
| stmt_rollback
{ $$ = $1; }
+ | stmt_let
+ { $$ = $1; }
;
stmt_perform : K_PERFORM
@@ -1010,6 +1013,30 @@ stmt_assign : T_DATUM
}
;
+stmt_let : K_LET
+ {
+ PLpgSQL_stmt_let *new;
+ RawParseMode pmode;
+
+ pmode = RAW_PARSE_PLPGSQL_LET;
+
+ new = palloc0(sizeof(PLpgSQL_stmt_let));
+ new->cmd_type = PLPGSQL_STMT_LET;
+ new->lineno = plpgsql_location_to_lineno(@1, yyscanner);
+ new->stmtid = ++plpgsql_curr_compile->nstatements;
+
+ /* push back the head name to include it in the stmt */
+ plpgsql_push_back_token(K_LET, &yylval, &yylloc, yyscanner);
+ new->expr = read_sql_construct(';', 0, 0, ";",
+ pmode,
+ false, true,
+ NULL, NULL,
+ &yylval, &yylloc, yyscanner);
+
+ $$ = (PLpgSQL_stmt *)new;
+ }
+ ;
+
stmt_getdiag : K_GET getdiag_area_opt K_DIAGNOSTICS getdiag_list ';'
{
PLpgSQL_stmt_getdiag *new;
diff --git a/src/pl/plpgsql/src/pl_reserved_kwlist.h b/src/pl/plpgsql/src/pl_reserved_kwlist.h
index ce7b0c9d331..e266bd1cc46 100644
--- a/src/pl/plpgsql/src/pl_reserved_kwlist.h
+++ b/src/pl/plpgsql/src/pl_reserved_kwlist.h
@@ -40,6 +40,7 @@ PG_KEYWORD("from", K_FROM)
PG_KEYWORD("if", K_IF)
PG_KEYWORD("in", K_IN)
PG_KEYWORD("into", K_INTO)
+PG_KEYWORD("let", K_LET)
PG_KEYWORD("loop", K_LOOP)
PG_KEYWORD("not", K_NOT)
PG_KEYWORD("null", K_NULL)
diff --git a/src/pl/plpgsql/src/pl_unreserved_kwlist.h b/src/pl/plpgsql/src/pl_unreserved_kwlist.h
index 98f99ec470c..ed14fd86c31 100644
--- a/src/pl/plpgsql/src/pl_unreserved_kwlist.h
+++ b/src/pl/plpgsql/src/pl_unreserved_kwlist.h
@@ -69,6 +69,7 @@ PG_KEYWORD("info", K_INFO)
PG_KEYWORD("insert", K_INSERT)
PG_KEYWORD("is", K_IS)
PG_KEYWORD("last", K_LAST)
+PG_KEYWORD("let", K_LET)
PG_KEYWORD("log", K_LOG)
PG_KEYWORD("merge", K_MERGE)
PG_KEYWORD("message", K_MESSAGE)
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index d73996e09c0..c7538612f1a 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -128,6 +128,7 @@ typedef enum PLpgSQL_stmt_type
PLPGSQL_STMT_CALL,
PLPGSQL_STMT_COMMIT,
PLPGSQL_STMT_ROLLBACK,
+ PLPGSQL_STMT_LET,
} PLpgSQL_stmt_type;
/*
@@ -542,6 +543,17 @@ typedef struct PLpgSQL_stmt_assign
PLpgSQL_expr *expr;
} PLpgSQL_stmt_assign;
+/*
+ * Let statement
+ */
+typedef struct PLpgSQL_stmt_let
+{
+ PLpgSQL_stmt_type cmd_type;
+ int lineno;
+ unsigned int stmtid;
+ PLpgSQL_expr *expr;
+} PLpgSQL_stmt_let;
+
/*
* PERFORM statement
*/
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index d0658116683..c25d804f8c1 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1129,8 +1129,7 @@ ERROR: permission denied for session variable var1
CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: SQL statement "LET var1.a = var1.a + 10"
-PL/pgSQL function inline_code_block line 1 at SQL statement
+CONTEXT: PL/pgSQL function inline_code_block line 1 at LET
SET ROLE TO DEFAULT;
GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
SET ROLE TO regress_var_test_role;
@@ -1174,8 +1173,7 @@ ERROR: permission denied for session variable var1
CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: SQL statement "LET var1.a = var1.a + 10"
-PL/pgSQL function inline_code_block line 1 at SQL statement
+CONTEXT: PL/pgSQL function inline_code_block line 1 at LET
SET ROLE TO DEFAULT;
DROP VARIABLE var1;
DROP TABLE vartesttab;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 794cd7b7619..7ff39e9a0d2 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1907,6 +1907,7 @@ PLpgSQL_stmt_forq
PLpgSQL_stmt_fors
PLpgSQL_stmt_getdiag
PLpgSQL_stmt_if
+PLpgSQL_stmt_let
PLpgSQL_stmt_loop
PLpgSQL_stmt_open
PLpgSQL_stmt_perform
--
2.48.1
[text/x-patch] v20250220-0018-expression-with-session-variables-can-be-inlined.patch (4.2K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/6-v20250220-0018-expression-with-session-variables-can-be-inlined.patch)
download | inline diff:
From a9cebda78c33c2766021c0fd51bb47f35b2874ad Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sat, 20 Jan 2024 20:35:38 +0100
Subject: [PATCH 18/21] expression with session variables can be inlined
There is not an reason why session variables should to block inlining.
(of SQL functions). I can imagine some use cases like wrapping, and
inlining significantly reduces an overhead of SQL functions.
---
src/backend/optimizer/util/clauses.c | 37 ++++++++++++++-----
.../regress/expected/session_variables.out | 7 ++--
2 files changed, 30 insertions(+), 14 deletions(-)
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 175390c6c28..0eb52fa2081 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -4744,8 +4744,7 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
querytree->limitOffset ||
querytree->limitCount ||
querytree->setOperations ||
- (list_length(querytree->targetList) != 1) ||
- querytree->hasSessionVariables)
+ (list_length(querytree->targetList) != 1))
goto fail;
/* If the function result is composite, resolve it */
@@ -4949,21 +4948,39 @@ substitute_actual_parameters_mutator(Node *node,
{
if (node == NULL)
return NULL;
+
+
+ /*
+ * SQL functions can contain two different kind of params. The nodes with
+ * paramkind PARAM_EXTERN are related to function's arguments (and should
+ * be replaced in this step), because this is how we apply the function's
+ * arguments for an expression.
+ *
+ * The nodes with paramkind PARAM_VARIABLE are related to usage of session
+ * variables. The values of session variables are not passed to expression
+ * by expression arguments, so it should not be replaced here by
+ * function's arguments.
+ */
if (IsA(node, Param))
{
Param *param = (Param *) node;
- if (param->paramkind != PARAM_EXTERN)
+ if (param->paramkind != PARAM_EXTERN &&
+ param->paramkind != PARAM_VARIABLE)
elog(ERROR, "unexpected paramkind: %d", (int) param->paramkind);
- if (param->paramid <= 0 || param->paramid > context->nargs)
- elog(ERROR, "invalid paramid: %d", param->paramid);
- /* Count usage of parameter */
- context->usecounts[param->paramid - 1]++;
+ if (param->paramkind == PARAM_EXTERN)
+ {
+ if (param->paramid <= 0 || param->paramid > context->nargs)
+ elog(ERROR, "invalid paramid: %d", param->paramid);
- /* Select the appropriate actual arg and replace the Param with it */
- /* We don't need to copy at this time (it'll get done later) */
- return list_nth(context->args, param->paramid - 1);
+ /* Count usage of parameter */
+ context->usecounts[param->paramid - 1]++;
+
+ /* Select the appropriate actual arg and replace the Param with it */
+ /* We don't need to copy at this time (it'll get done later) */
+ return list_nth(context->args, param->paramid - 1);
+ }
}
return expression_tree_mutator(node, substitute_actual_parameters_mutator, context);
}
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index c25d804f8c1..0d6c09ac42d 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -480,7 +480,6 @@ SELECT var1;
ERROR: permission denied for session variable var1
SELECT sqlfx(20);
ERROR: permission denied for session variable var1
-CONTEXT: SQL function "sqlfx" statement 1
SELECT plpgsqlfx(20);
ERROR: permission denied for session variable var1
CONTEXT: PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
@@ -587,10 +586,10 @@ SELECT sqlfx1(sqlfx2('Hello'));
-- inlining is blocked
EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
- QUERY PLAN
-------------------------------------------------------
+ QUERY PLAN
+-----------------------------------------------------------------------------
Result
- Output: sqlfx1(sqlfx2('Hello'::character varying))
+ Output: ((var1 || ', '::text) || ((var2 || ', '::text) || 'Hello'::text))
(2 rows)
DROP FUNCTION sqlfx1(varchar);
--
2.48.1
[text/x-patch] v20250220-0019-this-patch-changes-error-message-column-doesn-t-exis.patch (29.2K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/7-v20250220-0019-this-patch-changes-error-message-column-doesn-t-exis.patch)
download | inline diff:
From f59b7ef4cadda902b65d975d0539dfe2ee2525d8 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:10:39 +0100
Subject: [PATCH 19/21] this patch changes error message "column doesn't exist"
to message "column or variable doesn't exist"
The error message will be more correct. Today, missing PL/pgSQL variable can be reported. The change has
impact on lot of regress tests not directly related to session variables, and then it is distributed as separate patch
---
src/backend/parser/parse_expr.c | 2 +-
src/backend/parser/parse_relation.c | 24 +++++++++++---
src/backend/parser/parse_target.c | 8 +++--
src/include/parser/parse_expr.h | 2 ++
src/pl/plpgsql/src/expected/plpgsql_array.out | 2 +-
.../plpgsql/src/expected/plpgsql_record.out | 4 +--
.../src/expected/plpgsql_session_variable.out | 2 +-
src/pl/tcl/expected/pltcl_queries.out | 12 +++----
.../isolation/expected/session-variable.out | 4 +--
src/test/regress/expected/alter_table.out | 32 +++++++++----------
src/test/regress/expected/copy2.out | 2 +-
src/test/regress/expected/errors.out | 8 ++---
src/test/regress/expected/join.out | 12 +++----
src/test/regress/expected/namespace.out | 2 +-
src/test/regress/expected/numerology.out | 2 +-
src/test/regress/expected/plpgsql.out | 12 +++----
src/test/regress/expected/psql.out | 2 +-
src/test/regress/expected/rules.out | 2 +-
.../regress/expected/session_variables.out | 6 ++--
src/test/regress/expected/transactions.out | 4 +--
src/test/regress/expected/union.out | 2 +-
21 files changed, 83 insertions(+), 63 deletions(-)
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 158a67be523..7c4a584f0f4 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -526,7 +526,7 @@ transformIndirection(ParseState *pstate, A_Indirection *ind)
* printed. When we are in an expression where session variables cannot be
* used, we raise the first form of error message.
*/
-static bool
+bool
expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
{
bool result = false;
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index bec6947ea2d..7bc75319e50 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -27,6 +27,7 @@
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "parser/parse_enr.h"
+#include "parser/parse_expr.h"
#include "parser/parse_relation.h"
#include "parser/parse_type.h"
#include "parser/parsetree.h"
@@ -3761,6 +3762,19 @@ errorMissingRTE(ParseState *pstate, RangeVar *relation)
parser_errposition(pstate, relation->location)));
}
+/*
+ * set message "column does not exist" or "column or variable does not exist"
+ * in dependency if expression context allows session variables.
+ */
+static int
+column_or_variable_does_not_exists(ParseState *pstate, const char *colname)
+{
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind))
+ return errmsg("column or variable \"%s\" does not exist", colname);
+ else
+ return errmsg("column \"%s\" does not exist", colname);
+}
+
/*
* Generate a suitable error about a missing column.
*
@@ -3795,7 +3809,7 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errdetail("There are columns named \"%s\", but they are in tables that cannot be referenced from this part of the query.",
colname),
!relname ? errhint("Try using a table-qualified name.") : 0,
@@ -3805,7 +3819,7 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errdetail("There is a column named \"%s\" in table \"%s\", but it cannot be referenced from this part of the query.",
colname, state->rexact1->eref->aliasname),
rte_visible_if_lateral(pstate, state->rexact1) ?
@@ -3823,14 +3837,14 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
parser_errposition(pstate, location)));
/* Handle case where we have a single alternative spelling to offer */
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errhint("Perhaps you meant to reference the column \"%s.%s\".",
state->rfirst->eref->aliasname,
strVal(list_nth(state->rfirst->eref->colnames,
@@ -3844,7 +3858,7 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errhint("Perhaps you meant to reference the column \"%s.%s\" or the column \"%s.%s\".",
state->rfirst->eref->aliasname,
strVal(list_nth(state->rfirst->eref->colnames,
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index cf01bff65a9..2a527887a8d 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -779,7 +779,9 @@ transformAssignmentIndirection(ParseState *pstate,
if (!typrelid)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
- errmsg("cannot assign to field \"%s\" of column \"%s\" because its type %s is not a composite type",
+ errmsg(expr_kind_allows_session_variables(pstate->p_expr_kind) ?
+ "cannot assign to field \"%s\" of column or variable \"%s\" because its type %s is not a composite type" :
+ "cannot assign to field \"%s\" of column \"%s\" because its type %s is not a composite type",
strVal(n), targetName,
format_type_be(targetTypeId)),
parser_errposition(pstate, location)));
@@ -788,7 +790,9 @@ transformAssignmentIndirection(ParseState *pstate,
if (attnum == InvalidAttrNumber)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
- errmsg("cannot assign to field \"%s\" of column \"%s\" because there is no such column in data type %s",
+ errmsg(expr_kind_allows_session_variables(pstate->p_expr_kind) ?
+ "cannot assign to field \"%s\" of column or variable \"%s\" because there is no such column in data type %s" :
+ "cannot assign to field \"%s\" of column \"%s\" because there is no such column in data type %s",
strVal(n), targetName,
format_type_be(targetTypeId)),
parser_errposition(pstate, location)));
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index 5bde43758d1..71ec213f884 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -24,4 +24,6 @@ extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKin
extern const char *ParseExprKindName(ParseExprKind exprKind);
+extern bool expr_kind_allows_session_variables(ParseExprKind p_expr_kind);
+
#endif /* PARSE_EXPR_H */
diff --git a/src/pl/plpgsql/src/expected/plpgsql_array.out b/src/pl/plpgsql/src/expected/plpgsql_array.out
index 4c6b3ce998a..ad6692c3e52 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_array.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_array.out
@@ -41,7 +41,7 @@ NOTICE: a = {"(,11)"}, a[1].i = 11
-- perhaps this ought to work, but for now it doesn't:
do $$ declare a complex[];
begin a[1:2].i := array[11,12]; raise notice 'a = %', a; end$$;
-ERROR: cannot assign to field "i" of column "a" because its type complex[] is not a composite type
+ERROR: cannot assign to field "i" of column or variable "a" because its type complex[] is not a composite type
LINE 1: a[1:2].i := array[11,12]
^
QUERY: a[1:2].i := array[11,12]
diff --git a/src/pl/plpgsql/src/expected/plpgsql_record.out b/src/pl/plpgsql/src/expected/plpgsql_record.out
index 6974c8f4a44..3970ac721c9 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_record.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_record.out
@@ -135,7 +135,7 @@ ERROR: record "c" has no field "x"
CONTEXT: PL/pgSQL assignment "c.x.q1 = 1"
PL/pgSQL function inline_code_block line 1 at assignment
do $$ declare c nested_int8s; begin c.c2.x = 1; end $$;
-ERROR: cannot assign to field "x" of column "c" because there is no such column in data type two_int8s
+ERROR: cannot assign to field "x" of column or variable "c" because there is no such column in data type two_int8s
LINE 1: c.c2.x = 1
^
QUERY: c.c2.x = 1
@@ -157,7 +157,7 @@ ERROR: record "c" has no field "x"
CONTEXT: PL/pgSQL assignment "b.c.x.q1 = 1"
PL/pgSQL function inline_code_block line 1 at assignment
do $$ <<b>> declare c nested_int8s; begin b.c.c2.x = 1; end $$;
-ERROR: cannot assign to field "x" of column "b" because there is no such column in data type two_int8s
+ERROR: cannot assign to field "x" of column or variable "b" because there is no such column in data type two_int8s
LINE 1: b.c.c2.x = 1
^
QUERY: b.c.c2.x = 1
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index ecac64fcfb4..8bd2b398bdd 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -232,7 +232,7 @@ SET ROLE TO DEFAULT;
SET ROLE TO regress_var_exec_role;
-- should fail, but not crash
SELECT var_read_func();
-ERROR: column "plpgsql_sv_var1" does not exist
+ERROR: column or variable "plpgsql_sv_var1" does not exist
LINE 1: plpgsql_sv_var1
^
QUERY: plpgsql_sv_var1
diff --git a/src/pl/tcl/expected/pltcl_queries.out b/src/pl/tcl/expected/pltcl_queries.out
index 35cc6e62aad..497cd38189b 100644
--- a/src/pl/tcl/expected/pltcl_queries.out
+++ b/src/pl/tcl/expected/pltcl_queries.out
@@ -450,12 +450,12 @@ CONTEXT: while executing
"__PLTcl_proc_tcl_eval_text spi_prepare\ a\ \"b\ \{\""
in PL/Tcl function tcl_eval(text)
select tcl_error_handling_test($tcl$spi_prepare "select moo" []$tcl$);
- tcl_error_handling_test
---------------------------------------
- SQLSTATE: 42703 +
- condition: undefined_column +
- cursor_position: 8 +
- message: column "moo" does not exist+
+ tcl_error_handling_test
+--------------------------------------------------
+ SQLSTATE: 42703 +
+ condition: undefined_column +
+ cursor_position: 8 +
+ message: column or variable "moo" does not exist+
statement: select moo
(1 row)
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
index e9a254bcd12..d8848d555cd 100644
--- a/src/test/isolation/expected/session-variable.out
+++ b/src/test/isolation/expected/session-variable.out
@@ -10,7 +10,7 @@ test
step drop: DROP VARIABLE myvar;
step val: SELECT myvar;
-ERROR: column "myvar" does not exist
+ERROR: column or variable "myvar" does not exist
starting permutation: let val s1 drop val sr1
step let: LET myvar = 'test';
@@ -23,7 +23,7 @@ test
step s1: BEGIN;
step drop: DROP VARIABLE myvar;
step val: SELECT myvar;
-ERROR: column "myvar" does not exist
+ERROR: column or variable "myvar" does not exist
step sr1: ROLLBACK;
starting permutation: let val dbg drop create dbg val
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 362f38856d2..299dbdb5e43 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -1298,19 +1298,19 @@ select * from atacc1;
(1 row)
select * from atacc1 order by a;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select * from atacc1 order by a;
^
select * from atacc1 order by "........pg.dropped.1........";
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select * from atacc1 order by "........pg.dropped.1........"...
^
select * from atacc1 group by a;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select * from atacc1 group by a;
^
select * from atacc1 group by "........pg.dropped.1........";
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select * from atacc1 group by "........pg.dropped.1........"...
^
select atacc1.* from atacc1;
@@ -1320,7 +1320,7 @@ select atacc1.* from atacc1;
(1 row)
select a from atacc1;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select a from atacc1;
^
select atacc1.a from atacc1;
@@ -1334,15 +1334,15 @@ select b,c,d from atacc1;
(1 row)
select a,b,c,d from atacc1;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select a,b,c,d from atacc1;
^
select * from atacc1 where a = 1;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select * from atacc1 where a = 1;
^
select "........pg.dropped.1........" from atacc1;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select "........pg.dropped.1........" from atacc1;
^
select atacc1."........pg.dropped.1........" from atacc1;
@@ -1350,11 +1350,11 @@ ERROR: column atacc1.........pg.dropped.1........ does not exist
LINE 1: select atacc1."........pg.dropped.1........" from atacc1;
^
select "........pg.dropped.1........",b,c,d from atacc1;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select "........pg.dropped.1........",b,c,d from atacc1;
^
select * from atacc1 where "........pg.dropped.1........" = 1;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select * from atacc1 where "........pg.dropped.1........" = ...
^
-- UPDATEs
@@ -1363,7 +1363,7 @@ ERROR: column "a" of relation "atacc1" does not exist
LINE 1: update atacc1 set a = 3;
^
update atacc1 set b = 2 where a = 3;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: update atacc1 set b = 2 where a = 3;
^
update atacc1 set "........pg.dropped.1........" = 3;
@@ -1371,7 +1371,7 @@ ERROR: column "........pg.dropped.1........" of relation "atacc1" does not exis
LINE 1: update atacc1 set "........pg.dropped.1........" = 3;
^
update atacc1 set b = 2 where "........pg.dropped.1........" = 3;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: update atacc1 set b = 2 where "........pg.dropped.1........"...
^
-- INSERTs
@@ -1419,11 +1419,11 @@ LINE 1: insert into atacc1 ("........pg.dropped.1........",b,c,d) va...
^
-- DELETEs
delete from atacc1 where a = 3;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: delete from atacc1 where a = 3;
^
delete from atacc1 where "........pg.dropped.1........" = 3;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: delete from atacc1 where "........pg.dropped.1........" = 3;
^
delete from atacc1;
@@ -1716,7 +1716,7 @@ select f1 from c1;
alter table c1 drop column f1;
select f1 from c1;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1 from c1;
^
HINT: Perhaps you meant to reference the column "c1.f2".
@@ -1730,7 +1730,7 @@ ERROR: cannot drop inherited column "f1"
alter table p1 drop column f1;
-- c1.f1 is dropped now, since there is no local definition for it
select f1 from c1;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1 from c1;
^
HINT: Perhaps you meant to reference the column "c1.f2".
diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 64ea33aeae8..6874f5ae0d1 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -160,7 +160,7 @@ LINE 1: COPY x TO stdout WHERE a = 1;
COPY x from stdin WHERE a = 50004;
COPY x from stdin WHERE a > 60003;
COPY x from stdin WHERE f > 60003;
-ERROR: column "f" does not exist
+ERROR: column or variable "f" does not exist
LINE 1: COPY x from stdin WHERE f > 60003;
^
COPY x from stdin WHERE a = max(x.b);
diff --git a/src/test/regress/expected/errors.out b/src/test/regress/expected/errors.out
index 8c527474daf..e53ae451dfc 100644
--- a/src/test/regress/expected/errors.out
+++ b/src/test/regress/expected/errors.out
@@ -27,7 +27,7 @@ LINE 1: select * from nonesuch;
^
-- bad name in target list
select nonesuch from pg_database;
-ERROR: column "nonesuch" does not exist
+ERROR: column or variable "nonesuch" does not exist
LINE 1: select nonesuch from pg_database;
^
-- empty distinct list isn't OK
@@ -37,17 +37,17 @@ LINE 1: select distinct from pg_database;
^
-- bad attribute name on lhs of operator
select * from pg_database where nonesuch = pg_database.datname;
-ERROR: column "nonesuch" does not exist
+ERROR: column or variable "nonesuch" does not exist
LINE 1: select * from pg_database where nonesuch = pg_database.datna...
^
-- bad attribute name on rhs of operator
select * from pg_database where pg_database.datname = nonesuch;
-ERROR: column "nonesuch" does not exist
+ERROR: column or variable "nonesuch" does not exist
LINE 1: ...ect * from pg_database where pg_database.datname = nonesuch;
^
-- bad attribute name in select distinct on
select distinct on (foobar) * from pg_database;
-ERROR: column "foobar" does not exist
+ERROR: column or variable "foobar" does not exist
LINE 1: select distinct on (foobar) * from pg_database;
^
-- grouping with FOR UPDATE
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index a57bb18c24f..96359bdce1a 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -7477,13 +7477,13 @@ LINE 1: select t2.uunique1 from
HINT: Perhaps you meant to reference the column "t2.unique1".
select uunique1 from
tenk1 t1 join tenk2 t2 on t1.two = t2.two; -- error, suggest both at once
-ERROR: column "uunique1" does not exist
+ERROR: column or variable "uunique1" does not exist
LINE 1: select uunique1 from
^
HINT: Perhaps you meant to reference the column "t1.unique1" or the column "t2.unique1".
select ctid from
tenk1 t1 join tenk2 t2 on t1.two = t2.two; -- error, need qualification
-ERROR: column "ctid" does not exist
+ERROR: column or variable "ctid" does not exist
LINE 1: select ctid from
^
DETAIL: There are columns named "ctid", but they are in tables that cannot be referenced from this part of the query.
@@ -8580,7 +8580,7 @@ lateral (select * from int8_tbl t1,
-- test some error cases where LATERAL should have been used but wasn't
select f1,g from int4_tbl a, (select f1 as g) ss;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1,g from int4_tbl a, (select f1 as g) ss;
^
DETAIL: There is a column named "f1" in table "a", but it cannot be referenced from this part of the query.
@@ -8592,7 +8592,7 @@ LINE 1: select f1,g from int4_tbl a, (select a.f1 as g) ss;
DETAIL: There is an entry for table "a", but it cannot be referenced from this part of the query.
HINT: To reference that table, you must mark this subquery with LATERAL.
select f1,g from int4_tbl a cross join (select f1 as g) ss;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1,g from int4_tbl a cross join (select f1 as g) ss;
^
DETAIL: There is a column named "f1" in table "a", but it cannot be referenced from this part of the query.
@@ -8629,7 +8629,7 @@ LINE 1: select 1 from tenk1 a, lateral (select max(a.unique1) from i...
create temp table xx1 as select f1 as x1, -f1 as x2 from int4_tbl;
-- error, can't do this:
update xx1 set x2 = f1 from (select * from int4_tbl where f1 = x1) ss;
-ERROR: column "x1" does not exist
+ERROR: column or variable "x1" does not exist
LINE 1: ... set x2 = f1 from (select * from int4_tbl where f1 = x1) ss;
^
DETAIL: There is a column named "x1" in table "xx1", but it cannot be referenced from this part of the query.
@@ -8649,7 +8649,7 @@ update xx1 set x2 = f1 from xx1, lateral (select * from int4_tbl where f1 = x1)
ERROR: table name "xx1" specified more than once
-- also errors:
delete from xx1 using (select * from int4_tbl where f1 = x1) ss;
-ERROR: column "x1" does not exist
+ERROR: column or variable "x1" does not exist
LINE 1: ...te from xx1 using (select * from int4_tbl where f1 = x1) ss;
^
DETAIL: There is a column named "x1" in table "xx1", but it cannot be referenced from this part of the query.
diff --git a/src/test/regress/expected/namespace.out b/src/test/regress/expected/namespace.out
index dbbda72d395..d98793f92a7 100644
--- a/src/test/regress/expected/namespace.out
+++ b/src/test/regress/expected/namespace.out
@@ -23,7 +23,7 @@ BEGIN;
SET search_path to public, test_ns_schema_1;
CREATE SCHEMA test_ns_schema_2
CREATE VIEW abc_view AS SELECT c FROM abc;
-ERROR: column "c" does not exist
+ERROR: column or variable "c" does not exist
LINE 2: CREATE VIEW abc_view AS SELECT c FROM abc;
^
COMMIT;
diff --git a/src/test/regress/expected/numerology.out b/src/test/regress/expected/numerology.out
index 9e23166fed1..672012e1461 100644
--- a/src/test/regress/expected/numerology.out
+++ b/src/test/regress/expected/numerology.out
@@ -314,7 +314,7 @@ NOTICE: i = 1002
NOTICE: i = 1003
-- error cases
SELECT _100;
-ERROR: column "_100" does not exist
+ERROR: column or variable "_100" does not exist
LINE 1: SELECT _100;
^
SELECT 100_;
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index 0a6945581bd..5c599ba312e 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -2598,7 +2598,7 @@ end; $$ language plpgsql;
-- should fail: SQLSTATE and SQLERRM are only in defined EXCEPTION
-- blocks
select excpt_test1();
-ERROR: column "sqlstate" does not exist
+ERROR: column or variable "sqlstate" does not exist
LINE 1: sqlstate
^
QUERY: sqlstate
@@ -2613,7 +2613,7 @@ begin
end; $$ language plpgsql;
-- should fail
select excpt_test2();
-ERROR: column "sqlstate" does not exist
+ERROR: column or variable "sqlstate" does not exist
LINE 1: sqlstate
^
QUERY: sqlstate
@@ -4675,7 +4675,7 @@ BEGIN
RAISE NOTICE '%, %', r.roomno, r.comment;
END LOOP;
END$$;
-ERROR: column "foo" does not exist
+ERROR: column or variable "foo" does not exist
LINE 1: SELECT rtrim(roomno) AS roomno, foo FROM Room ORDER BY roomn...
^
QUERY: SELECT rtrim(roomno) AS roomno, foo FROM Room ORDER BY roomno
@@ -4717,7 +4717,7 @@ begin
raise notice 'x = %', x;
end;
$$;
-ERROR: column "x" does not exist
+ERROR: column or variable "x" does not exist
LINE 1: x + 1
^
QUERY: x + 1
@@ -4729,7 +4729,7 @@ begin
raise notice 'x = %, y = %', x, y;
end;
$$;
-ERROR: column "x" does not exist
+ERROR: column or variable "x" does not exist
LINE 1: x + 1
^
QUERY: x + 1
@@ -5769,7 +5769,7 @@ ALTER TABLE alter_table_under_transition_tables
DROP column name;
UPDATE alter_table_under_transition_tables
SET id = id;
-ERROR: column "name" does not exist
+ERROR: column or variable "name" does not exist
LINE 1: (SELECT string_agg(id || '=' || name, ',') FROM d)
^
QUERY: (SELECT string_agg(id || '=' || name, ',') FROM d)
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 78aca67e452..ec870172faa 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -214,7 +214,7 @@ select $1::int as col \bind 1 \g \bind 2 \g
-- errors
-- parse error
SELECT foo \bind \g
-ERROR: column "foo" does not exist
+ERROR: column or variable "foo" does not exist
LINE 1: SELECT foo
^
-- tcop error
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 5baba8d39ff..f1b5b73a86a 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1191,7 +1191,7 @@ drop rule rules_foorule on rules_foo;
-- this should fail because f1 is not exposed for unqualified reference:
create rule rules_foorule as on insert to rules_foo where f1 < 100
do instead insert into rules_foo2 values (f1);
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 2: do instead insert into rules_foo2 values (f1);
^
DETAIL: There are columns named "f1", but they are in tables that cannot be referenced from this part of the query.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 0d6c09ac42d..7b71bba90e9 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -811,7 +811,7 @@ ERROR: session variable "var1" doesn't exist
LINE 1: LET var1 = pi();
^
SELECT var1;
-ERROR: column "var1" does not exist
+ERROR: column or variable "var1" does not exist
LINE 1: SELECT var1;
^
-- should be ok
@@ -1030,7 +1030,7 @@ SELECT v1;
-- should fail, attribute doesn't exist
LET v1.x = 10;
-ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1
+ERROR: cannot assign to field "x" of column or variable "v1" because there is no such column in data type t1
LINE 1: LET v1.x = 10;
^
-- should fail, don't allow multi column query
@@ -1750,7 +1750,7 @@ BEGIN;
DROP VARIABLE var1;
-- should fail
SELECT var1;
-ERROR: column "var1" does not exist
+ERROR: column or variable "var1" does not exist
LINE 1: SELECT var1;
^
ROLLBACK;
diff --git a/src/test/regress/expected/transactions.out b/src/test/regress/expected/transactions.out
index 7f5757e89c4..b05b16d94bf 100644
--- a/src/test/regress/expected/transactions.out
+++ b/src/test/regress/expected/transactions.out
@@ -256,7 +256,7 @@ SELECT * FROM trans_barbaz; -- should have 1
BEGIN;
SAVEPOINT one;
SELECT trans_foo;
-ERROR: column "trans_foo" does not exist
+ERROR: column or variable "trans_foo" does not exist
LINE 1: SELECT trans_foo;
^
ROLLBACK TO SAVEPOINT one;
@@ -305,7 +305,7 @@ BEGIN;
SAVEPOINT one;
INSERT INTO savepoints VALUES (5);
SELECT trans_foo;
-ERROR: column "trans_foo" does not exist
+ERROR: column or variable "trans_foo" does not exist
LINE 1: SELECT trans_foo;
^
COMMIT;
diff --git a/src/test/regress/expected/union.out b/src/test/regress/expected/union.out
index caa8fe70a05..1d3447e84dd 100644
--- a/src/test/regress/expected/union.out
+++ b/src/test/regress/expected/union.out
@@ -939,7 +939,7 @@ ORDER BY q2,q1;
-- This should fail, because q2 isn't a name of an EXCEPT output column
SELECT q1 FROM int8_tbl EXCEPT SELECT q2 FROM int8_tbl ORDER BY q2 LIMIT 1;
-ERROR: column "q2" does not exist
+ERROR: column or variable "q2" does not exist
LINE 1: ... int8_tbl EXCEPT SELECT q2 FROM int8_tbl ORDER BY q2 LIMIT 1...
^
DETAIL: There is a column named "q2" in table "*SELECT* 2", but it cannot be referenced from this part of the query.
--
2.48.1
[text/x-patch] v20250220-0016-allow-parallel-execution-queries-with-session-variab.patch (15.8K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/8-v20250220-0016-allow-parallel-execution-queries-with-session-variab.patch)
download | inline diff:
From 395bd8eb74de4b9a96044f56e77174fea0afd071 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:08:17 +0100
Subject: [PATCH 16/21] allow parallel execution queries with session variables
---
doc/src/sgml/parallel.sgml | 6 -
src/backend/commands/session_variable.c | 23 +++
src/backend/executor/execMain.c | 20 ++-
src/backend/executor/execParallel.c | 147 +++++++++++++++++-
src/backend/optimizer/util/clauses.c | 18 +--
src/backend/tcop/pquery.c | 3 +
src/include/commands/session_variable.h | 1 +
src/include/executor/execdesc.h | 4 +
src/include/nodes/execnodes.h | 1 +
.../regress/expected/session_variables.out | 12 +-
10 files changed, 206 insertions(+), 29 deletions(-)
diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index 683dede6adc..1ce9abf86f5 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -515,12 +515,6 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
Plan nodes that reference a correlated <literal>SubPlan</literal>.
</para>
</listitem>
-
- <listitem>
- <para>
- Plan nodes that use a session variable.
- </para>
- </listitem>
</itemizedlist>
<sect2 id="parallel-labeling">
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 95dd7445c15..bb6abb792be 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -991,6 +991,29 @@ GetSessionVariable(Oid varid, bool *isNull)
return copy_session_variable_value(svar, isNull);
}
+/*
+ * Returns a copy of the value of the session variable (in the current memory
+ * context) plus typid of the session variable. The caller is responsible for
+ * permission checks.
+ */
+Datum
+GetSessionVariableWithTypeid(Oid varid, bool *isNull, Oid *typid)
+{
+ SVariable svar;
+
+ svar = get_session_variable(varid);
+
+ *typid = svar->typid;
+
+ /*
+ * Although "svar" is freshly validated in this point, svar->is_valid can
+ * be false, if an invalidation message was processed during the domain check.
+ * But the variable and all its dependencies are locked now, so we don't need
+ * to repeat the validation.
+ */
+ return copy_session_variable_value(svar, isNull);
+}
+
/*
* Assign the result of the evaluated expression to the session variable
*/
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 67e0b9ba2ac..1feba422bfb 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -220,7 +220,19 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
* be changed inside query execution time, and then a reference to
* previously returned value can be corrupted).
*/
- if (queryDesc->plannedstmt->sessionVariables)
+ if (queryDesc->num_session_variables > 0)
+ {
+ /*
+ * When a parallel query needs to access query parameters (including
+ * related session variables), then related session variables are
+ * restored (deserialized) in queryDesc already. So just push pointer
+ * of this array to executor's estate.
+ */
+ Assert(IsParallelWorker());
+ estate->es_session_variables = queryDesc->session_variables;
+ estate->es_num_session_variables = queryDesc->num_session_variables;
+ }
+ else if (queryDesc->plannedstmt->sessionVariables)
{
int nSessionVariables;
int i = 0;
@@ -259,9 +271,9 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
get_session_variable_name(varid));
}
- estate->es_session_variables[i].value =
- GetSessionVariable(varid,
- &estate->es_session_variables[i].isnull);
+ estate->es_session_variables[i].value = GetSessionVariableWithTypeid(varid,
+ &estate->es_session_variables[i].isnull,
+ &estate->es_session_variables[i].typid);
i++;
}
diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c
index 1bedb808368..aee66beac91 100644
--- a/src/backend/executor/execParallel.c
+++ b/src/backend/executor/execParallel.c
@@ -12,8 +12,9 @@
* workers and ensuring that their state generally matches that of the
* leader; see src/backend/access/transam/README.parallel for details.
* However, we must save and restore relevant executor state, such as
- * any ParamListInfo associated with the query, buffer/WAL usage info, and
- * the actual plan to be passed down to the worker.
+ * any ParamListInfo associated with the query, buffer/WAL usage info,
+ * session variables buffer, and the actual plan to be passed down to
+ * the worker.
*
* IDENTIFICATION
* src/backend/executor/execParallel.c
@@ -64,6 +65,7 @@
#define PARALLEL_KEY_QUERY_TEXT UINT64CONST(0xE000000000000008)
#define PARALLEL_KEY_JIT_INSTRUMENTATION UINT64CONST(0xE000000000000009)
#define PARALLEL_KEY_WAL_USAGE UINT64CONST(0xE00000000000000A)
+#define PARALLEL_KEY_SESSION_VARIABLES UINT64CONST(0xE00000000000000B)
#define PARALLEL_TUPLE_QUEUE_SIZE 65536
@@ -138,6 +140,12 @@ static bool ExecParallelRetrieveInstrumentation(PlanState *planstate,
/* Helper function that runs in the parallel worker. */
static DestReceiver *ExecParallelGetReceiver(dsm_segment *seg, shm_toc *toc);
+/* Helper functions that can pass values of session variables */
+static Size EstimateSessionVariables(EState *estate);
+static void SerializeSessionVariables(EState *estate, char **start_address);
+static SessionVariableValue *RestoreSessionVariables(char **start_address,
+ int *num_session_variables);
+
/*
* Create a serialized representation of the plan to be sent to each worker.
*/
@@ -598,6 +606,7 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
char *pstmt_data;
char *pstmt_space;
char *paramlistinfo_space;
+ char *session_variables_space;
BufferUsage *bufusage_space;
WalUsage *walusage_space;
SharedExecutorInstrumentation *instrumentation = NULL;
@@ -607,6 +616,7 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
int instrumentation_len = 0;
int jit_instrumentation_len = 0;
int instrument_offset = 0;
+ int session_variables_len = 0;
Size dsa_minsize = dsa_minimum_size();
char *query_string;
int query_len;
@@ -662,6 +672,11 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
shm_toc_estimate_chunk(&pcxt->estimator, paramlistinfo_len);
shm_toc_estimate_keys(&pcxt->estimator, 1);
+ /* Estimate space for serialized session variables. */
+ session_variables_len = EstimateSessionVariables(estate);
+ shm_toc_estimate_chunk(&pcxt->estimator, session_variables_len);
+ shm_toc_estimate_keys(&pcxt->estimator, 1);
+
/*
* Estimate space for BufferUsage.
*
@@ -763,6 +778,11 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
shm_toc_insert(pcxt->toc, PARALLEL_KEY_PARAMLISTINFO, paramlistinfo_space);
SerializeParamList(estate->es_param_list_info, ¶mlistinfo_space);
+ /* Store serialized session variables. */
+ session_variables_space = shm_toc_allocate(pcxt->toc, session_variables_len);
+ shm_toc_insert(pcxt->toc, PARALLEL_KEY_SESSION_VARIABLES, session_variables_space);
+ SerializeSessionVariables(estate, &session_variables_space);
+
/* Allocate space for each worker's BufferUsage; no need to initialize. */
bufusage_space = shm_toc_allocate(pcxt->toc,
mul_size(sizeof(BufferUsage), pcxt->nworkers));
@@ -1420,6 +1440,7 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
SharedJitInstrumentation *jit_instrumentation;
int instrument_options = 0;
void *area_space;
+ char *sessionvariable_space;
dsa_area *area;
ParallelWorkerContext pwcxt;
@@ -1445,6 +1466,14 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
area_space = shm_toc_lookup(toc, PARALLEL_KEY_DSA, false);
area = dsa_attach_in_place(area_space, seg);
+ /* Reconstruct session variables. */
+ sessionvariable_space = shm_toc_lookup(toc,
+ PARALLEL_KEY_SESSION_VARIABLES,
+ false);
+ queryDesc->session_variables =
+ RestoreSessionVariables(&sessionvariable_space,
+ &queryDesc->num_session_variables);
+
/* Start up the executor */
queryDesc->plannedstmt->jitFlags = fpes->jit_flags;
if (!ExecutorStart(queryDesc, fpes->eflags))
@@ -1513,3 +1542,117 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
FreeQueryDesc(queryDesc);
receiver->rDestroy(receiver);
}
+
+/*
+ * Estimate the amount of space required to serialize a session variable.
+ */
+static Size
+EstimateSessionVariables(EState *estate)
+{
+ int i;
+ Size sz = sizeof(int);
+
+ if (estate->es_session_variables == NULL)
+ return sz;
+
+ for (i = 0; i < estate->es_num_session_variables; i++)
+ {
+ SessionVariableValue *svarval;
+ Oid typeOid;
+ int16 typLen;
+ bool typByVal;
+
+ svarval = &estate->es_session_variables[i];
+
+ typeOid = svarval->typid;
+
+ sz = add_size(sz, sizeof(Oid)); /* space for type OID */
+
+ /* space for datum/isnull */
+ Assert(OidIsValid(typeOid));
+ get_typlenbyval(typeOid, &typLen, &typByVal);
+
+ sz = add_size(sz,
+ datumEstimateSpace(svarval->value, svarval->isnull, typByVal, typLen));
+ }
+
+ return sz;
+}
+
+/*
+ * Serialize a session variables buffer into caller-provided storage.
+ *
+ * We write the number of parameters first, as a 4-byte integer, and then
+ * write details for each parameter in turn. The details for each parameter
+ * consist of a 4-byte type OID, and then the datum as serialized by
+ * datumSerialize(). The caller is responsible for ensuring that there is
+ * enough storage to store the number of bytes that will be written; use
+ * EstimateSessionVariables to find out how many will be needed.
+ * *start_address is updated to point to the byte immediately following those
+ * written.
+ *
+ * RestoreSessionVariables can be used to recreate a session variable buffer
+ * based on the serialized representation;
+ */
+static void
+SerializeSessionVariables(EState *estate, char **start_address)
+{
+ int nparams;
+ int i;
+
+ /* Write number of parameters. */
+ nparams = estate->es_num_session_variables;
+ memcpy(*start_address, &nparams, sizeof(int));
+ *start_address += sizeof(int);
+
+ /* Write each parameter in turn. */
+ for (i = 0; i < nparams; i++)
+ {
+ SessionVariableValue *svarval;
+ Oid typeOid;
+ int16 typLen;
+ bool typByVal;
+
+ svarval = &estate->es_session_variables[i];
+ typeOid = svarval->typid;
+
+ /* Write type OID. */
+ memcpy(*start_address, &typeOid, sizeof(Oid));
+ *start_address += sizeof(Oid);
+
+ Assert(OidIsValid(typeOid));
+ get_typlenbyval(typeOid, &typLen, &typByVal);
+
+ datumSerialize(svarval->value, svarval->isnull, typByVal, typLen,
+ start_address);
+ }
+}
+
+static SessionVariableValue *
+RestoreSessionVariables(char **start_address, int *num_session_variables)
+{
+ SessionVariableValue *session_variables;
+ int i;
+ int nparams;
+
+ memcpy(&nparams, *start_address, sizeof(int));
+ *start_address += sizeof(int);
+
+ *num_session_variables = nparams;
+ session_variables = (SessionVariableValue *)
+ palloc(nparams * sizeof(SessionVariableValue));
+
+ for (i = 0; i < nparams; i++)
+ {
+ SessionVariableValue *svarval = &session_variables[i];
+
+ /* Read type OID. */
+ memcpy(&svarval->typid, *start_address, sizeof(Oid));
+ *start_address += sizeof(Oid);
+
+ /* Read datum/isnull. */
+ svarval->value = datumRestore(start_address, &svarval->isnull);
+ }
+
+ return session_variables;
+}
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index f60828f862e..175390c6c28 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -923,25 +923,19 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
/*
* We can't pass Params to workers at the moment either, so they are also
- * parallel-restricted, unless they are PARAM_EXTERN Params or are
- * PARAM_EXEC Params listed in safe_param_ids, meaning they could be
- * either generated within workers or can be computed by the leader and
- * then their value can be passed to workers.
+ * parallel-restricted, unless they are PARAM_EXTERN or PARAM_VARIABLE
+ * Params or are PARAM_EXEC Params listed in safe_param_ids, meaning they
+ * could be either generated within workers or can be computed by the
+ * leader and then their value can be passed to workers.
*/
else if (IsA(node, Param))
{
Param *param = (Param *) node;
- if (param->paramkind == PARAM_EXTERN)
+ if (param->paramkind == PARAM_EXTERN ||
+ param->paramkind == PARAM_VARIABLE)
return false;
- /* we don't support passing session variables to workers */
- if (param->paramkind == PARAM_VARIABLE)
- {
- if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
- return true;
- }
-
if (param->paramkind != PARAM_EXEC ||
!list_member_int(context->safe_param_ids, param->paramid))
{
diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c
index dea24453a6c..dce885190c2 100644
--- a/src/backend/tcop/pquery.c
+++ b/src/backend/tcop/pquery.c
@@ -92,6 +92,9 @@ CreateQueryDesc(PlannedStmt *plannedstmt,
qd->queryEnv = queryEnv;
qd->instrument_options = instrument_options; /* instrumentation wanted? */
+ qd->num_session_variables = 0;
+ qd->session_variables = NULL;
+
/* null these fields until set by ExecutorStart */
qd->tupDesc = NULL;
qd->estate = NULL;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index 4492bee6d69..f66b6c0b864 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -29,6 +29,7 @@ extern void AtEOSubXact_SessionVariables(bool isCommit, SubTransactionId mySubid
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
+extern Datum GetSessionVariableWithTypeid(Oid varid, bool *isNull, Oid *typid);
extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
QueryEnvironment *queryEnv, QueryCompletion *qc);
diff --git a/src/include/executor/execdesc.h b/src/include/executor/execdesc.h
index ba53305ad42..41eeb1c83c9 100644
--- a/src/include/executor/execdesc.h
+++ b/src/include/executor/execdesc.h
@@ -52,6 +52,10 @@ typedef struct QueryDesc
/* This field is set by ExecutePlan */
bool already_executed; /* true if previously executed */
+ /* reference to session variables buffer */
+ int num_session_variables;
+ SessionVariableValue *session_variables;
+
/* This is always set NULL by the core system, but plugins can change it */
struct Instrumentation *totaltime; /* total time spent in ExecutorRun */
} QueryDesc;
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 1b8ad640922..5632f77aee7 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -642,6 +642,7 @@ typedef struct AsyncRequest
*/
typedef struct SessionVariableValue
{
+ Oid typid;
bool isnull;
Datum value;
} SessionVariableValue;
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 0ed2d5fbb01..d0658116683 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1284,12 +1284,14 @@ SELECT count(*) FROM svar_test WHERE a%10 = zero;
-- parallel execution is not supported yet
EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
- QUERY PLAN
------------------------------------
+ QUERY PLAN
+--------------------------------------------
Aggregate
- -> Seq Scan on svar_test
- Filter: ((a % 10) = zero)
-(3 rows)
+ -> Gather
+ Workers Planned: 2
+ -> Parallel Seq Scan on svar_test
+ Filter: ((a % 10) = zero)
+(5 rows)
LET zero = (SELECT count(*) FROM svar_test);
-- result should be 1000
--
2.48.1
[text/x-patch] v20250220-0015-allow-read-an-value-of-session-variable-directly-fro.patch (15.1K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/9-v20250220-0015-allow-read-an-value-of-session-variable-directly-fro.patch)
download | inline diff:
From fb233b4075008996fdf05eab7307b45d8adfb0f9 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:07:03 +0100
Subject: [PATCH 15/21] allow read an value of session variable directly from
expression executor
The expression executor can be called directly (not inside query executor)
when expression is evaluated as simple expression in plpgsql or when expression
is an argument of CALL or EXECUTE statements. For these cases we need to allow direct
access to content of session variables from executor. We can do it, because
we know so the expression is not evaluated under query and cannot be
evaluated inside parallel worker.
This patch enables session variables for simple expression evaluation.
This patch enables usage session variables in arguments of CALL stmt.
---
src/backend/commands/prepare.c | 10 ---
src/backend/executor/execExpr.c | 86 +++++++++++++++----
src/backend/executor/execExprInterp.c | 14 +++
src/backend/jit/llvm/llvmjit_expr.c | 6 ++
src/backend/parser/analyze.c | 10 ---
src/include/executor/execExpr.h | 11 ++-
.../src/expected/plpgsql_session_variable.out | 3 +-
src/pl/plpgsql/src/pl_exec.c | 3 +-
.../regress/expected/session_variables.out | 38 ++++----
src/test/regress/sql/session_variables.sql | 12 +--
10 files changed, 125 insertions(+), 68 deletions(-)
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 0f9330005df..169a07eec4f 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -339,16 +339,6 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
i++;
}
- /*
- * The arguments of EXECUTE are evaluated by a direct expression
- * executor call. This mode doesn't support session variables yet.
- * It will be enabled later.
- */
- if (pstate->p_hasSessionVariables)
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("session variable cannot be used as an argument")));
-
/* Prepare the expressions for execution */
exprstates = ExecPrepareExprList(params, estate);
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 270e6d344be..d07377948a0 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -34,6 +34,8 @@
#include "catalog/objectaccess.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
#include "executor/execExpr.h"
#include "executor/nodeSubplan.h"
#include "funcapi.h"
@@ -1054,22 +1056,74 @@ ExecInitExprRec(Expr *node, ExprState *state,
es_num_session_variables = state->parent->state->es_num_session_variables;
}
- Assert(es_session_variables);
-
- /* parameter sanity checks */
- if (param->paramid >= es_num_session_variables)
- elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
-
- var = &es_session_variables[param->paramid];
-
- /*
- * In this case, pass the value like a
- * constant.
- */
- scratch.opcode = EEOP_CONST;
- scratch.d.constval.value = var->value;
- scratch.d.constval.isnull = var->isnull;
- ExprEvalPushStep(state, &scratch);
+ if (es_session_variables)
+ {
+ /*
+ * This path is used when expression is
+ * evaluated inside query evaluation. For
+ * ensuring of immutability of session variable
+ * inside query we use special buffer with copy
+ * of used session variables. This method helps
+ * with parallel execution too.
+ */
+
+ /* parameter sanity checks */
+ if (param->paramid >= es_num_session_variables)
+ elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
+
+ var = &es_session_variables[param->paramid];
+
+ /*
+ * In this case, pass the value like a
+ * constant.
+ */
+ scratch.opcode = EEOP_CONST;
+ scratch.d.constval.value = var->value;
+ scratch.d.constval.isnull = var->isnull;
+ ExprEvalPushStep(state, &scratch);
+ }
+ else
+ {
+ Oid varid = param->paramvarid;
+
+ Assert(!IsParallelWorker());
+
+ /*
+ * In some cases (plpgsql's simple expression
+ * evaluation or evaluation of CALL arguments),
+ * the expression executor is called directly.
+ * We can allow direct access to session
+ * variables (copy only), because we know, so
+ * outside is not any query (and expression
+ * cannot be executed parallel).
+ *
+ * In this case we should to do aclcheck,
+ * because usual aclcheck from
+ * standard_ExecutorStart is not executed in
+ * this case. Fortunately it is just once per
+ * transaction.
+ *
+ * Don't do permission check, when variable is
+ * used like base node for assignment indirection.
+ */
+ if (!param->parambasenode)
+ {
+ AclResult aclresult;
+
+ aclresult = object_aclcheck(
+ VariableRelationId, varid,
+ GetUserId(), ACL_SELECT);
+
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult,
+ OBJECT_VARIABLE,
+ get_session_variable_name(varid));
+ }
+
+ scratch.opcode = EEOP_PARAM_VARIABLE;
+ scratch.d.vparam.varid = varid;
+ ExprEvalPushStep(state, &scratch);
+ }
}
break;
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 1c3477b03c9..45ec7b58610 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -59,6 +59,7 @@
#include "access/heaptoast.h"
#include "catalog/pg_type.h"
#include "commands/sequence.h"
+#include "commands/session_variable.h"
#include "executor/execExpr.h"
#include "executor/nodeSubplan.h"
#include "funcapi.h"
@@ -521,6 +522,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
&&CASE_EEOP_PARAM_EXEC,
&&CASE_EEOP_PARAM_EXTERN,
&&CASE_EEOP_PARAM_CALLBACK,
+ &&CASE_EEOP_PARAM_VARIABLE,
&&CASE_EEOP_PARAM_SET,
&&CASE_EEOP_CASE_TESTVAL,
&&CASE_EEOP_CASE_TESTVAL_EXT,
@@ -1265,6 +1267,18 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
EEO_NEXT();
}
+ EEO_CASE(EEOP_PARAM_VARIABLE)
+ {
+ /*
+ * Direct access to session variable (without buffering). Because
+ * returned value can be used (without an assignement) after the
+ * referenced session variables is updated, we have to use an copy
+ * of stored value every time.
+ */
+ *op->resvalue = GetSessionVariable(op->d.vparam.varid, op->resnull);
+ EEO_NEXT();
+ }
+
EEO_CASE(EEOP_PARAM_SET)
{
/* out of line, unlikely to matter performance-wise */
diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c
index f0f5c3bd49f..ad8d80cf49c 100644
--- a/src/backend/jit/llvm/llvmjit_expr.c
+++ b/src/backend/jit/llvm/llvmjit_expr.c
@@ -1208,6 +1208,12 @@ llvm_compile_expr(ExprState *state)
break;
}
+ case EEOP_PARAM_VARIABLE:
+ build_EvalXFunc(b, mod, "ExecEvalParamVariable",
+ v_state, op, v_econtext);
+ LLVMBuildBr(b, opblocks[opno + 1]);
+ break;
+
case EEOP_PARAM_SET:
build_EvalXFunc(b, mod, "ExecEvalParamSet",
v_state, op, v_econtext);
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index c0c3abd7a0e..46a22ff5c94 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -3571,16 +3571,6 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt)
true,
stmt->funccall->location);
- /*
- * The arguments of CALL statement are evaluated by a direct expression
- * executor call. This path is unsupported yet, so block it. It will be
- * enabled later.
- */
- if (pstate->p_hasSessionVariables)
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("session variable cannot be used as an argument")));
-
assign_expr_collations(pstate, node);
fexpr = castNode(FuncExpr, node);
diff --git a/src/include/executor/execExpr.h b/src/include/executor/execExpr.h
index 191d8fe34de..1259ef72bac 100644
--- a/src/include/executor/execExpr.h
+++ b/src/include/executor/execExpr.h
@@ -164,10 +164,11 @@ typedef enum ExprEvalOp
EEOP_BOOLTEST_IS_FALSE,
EEOP_BOOLTEST_IS_NOT_FALSE,
- /* evaluate PARAM_EXEC/EXTERN parameters */
+ /* evaluate PARAM_EXEC/EXTERN/VARIABLE parameters */
EEOP_PARAM_EXEC,
EEOP_PARAM_EXTERN,
EEOP_PARAM_CALLBACK,
+ EEOP_PARAM_VARIABLE,
/* set PARAM_EXEC value */
EEOP_PARAM_SET,
@@ -430,6 +431,12 @@ typedef struct ExprEvalStep
Oid paramtype; /* OID of parameter's datatype */
} cparam;
+ /* for EEOP_PARAM_VARIABLE */
+ struct
+ {
+ Oid varid; /* OID of assigned variable */
+ } vparam;
+
/* for EEOP_CASE_TESTVAL/DOMAIN_TESTVAL */
struct
{
@@ -852,6 +859,8 @@ extern void ExecEvalParamSet(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalParamExtern(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
+extern void ExecEvalParamVariable(ExprState *state, ExprEvalStep *op,
+ ExprContext *econtext);
extern void ExecEvalCoerceViaIOSafe(ExprState *state, ExprEvalStep *op);
extern void ExecEvalSQLValueFunction(ExprState *state, ExprEvalStep *op);
extern void ExecEvalCurrentOfExpr(ExprState *state, ExprEvalStep *op);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index a6523f7afe2..ecac64fcfb4 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -211,8 +211,7 @@ SET ROLE TO regress_var_exec_role;
-- should fail
SELECT var_read_func();
ERROR: permission denied for session variable plpgsql_sv_var1
-CONTEXT: PL/pgSQL expression "plpgsql_sv_var1"
-PL/pgSQL function var_read_func() line 3 at RAISE
+CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE
SET ROLE TO DEFAULT;
SET ROLE TO regress_var_owner_role;
GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index cb282404c1a..d4377ceecbf 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8264,8 +8264,7 @@ exec_is_simple_query(PLpgSQL_expr *expr)
query->sortClause ||
query->limitOffset ||
query->limitCount ||
- query->setOperations ||
- query->hasSessionVariables)
+ query->setOperations)
return false;
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 548c0e3bcd2..0ed2d5fbb01 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -483,8 +483,7 @@ ERROR: permission denied for session variable var1
CONTEXT: SQL function "sqlfx" statement 1
SELECT plpgsqlfx(20);
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "$1 + var1"
-PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
+CONTEXT: PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
-- should be ok
SELECT sqlfx_sd(20);
sqlfx_sd
@@ -780,27 +779,28 @@ $$;
NOTICE: result array: {1,2,3,4,5,6,7,8,9,10}
DROP VARIABLE var1;
DROP VARIABLE var2;
--- CALL statement is not supported yet
--- requires direct access to session variable from expression executor
+-- CALL statement is supported
CREATE VARIABLE v int;
+LET v = 1;
CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
--- should not crash (but is not supported yet)
+-- should to work
CALL p(v);
-ERROR: session variable cannot be used as an argument
+NOTICE: 1
DO $$ BEGIN CALL p(v); END $$;
-ERROR: session variable cannot be used as an argument
-CONTEXT: SQL statement "CALL p(v)"
-PL/pgSQL function inline_code_block line 1 at CALL
+NOTICE: 1
DROP PROCEDURE p(int);
DROP VARIABLE v;
--- EXECUTE statement is not supported yet
--- requires direct access to session variable from expression executor
+-- EXECUTE statement
CREATE VARIABLE v int;
LET v = 20;
PREPARE ptest(int) AS SELECT $1;
--- should fail
+-- should be ok
EXECUTE ptest(v);
-ERROR: session variable cannot be used as an argument
+ ?column?
+----------
+ 20
+(1 row)
+
DEALLOCATE ptest;
DROP VARIABLE v;
-- test search path
@@ -1123,12 +1123,10 @@ LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a
ERROR: permission denied for session variable var1
DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1.a"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
CONTEXT: SQL statement "LET var1.a = var1.a + 10"
@@ -1170,12 +1168,10 @@ LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a
ERROR: permission denied for session variable var1
DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1.a"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
CONTEXT: SQL statement "LET var1.a = var1.a + 10"
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 282ba5c8639..c8c2295adbd 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -548,13 +548,14 @@ $$;
DROP VARIABLE var1;
DROP VARIABLE var2;
--- CALL statement is not supported yet
--- requires direct access to session variable from expression executor
+-- CALL statement is supported
CREATE VARIABLE v int;
+LET v = 1;
+
CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
--- should not crash (but is not supported yet)
+-- should to work
CALL p(v);
DO $$ BEGIN CALL p(v); END $$;
@@ -562,13 +563,12 @@ DO $$ BEGIN CALL p(v); END $$;
DROP PROCEDURE p(int);
DROP VARIABLE v;
--- EXECUTE statement is not supported yet
--- requires direct access to session variable from expression executor
+-- EXECUTE statement
CREATE VARIABLE v int;
LET v = 20;
PREPARE ptest(int) AS SELECT $1;
--- should fail
+-- should be ok
EXECUTE ptest(v);
DEALLOCATE ptest;
--
2.48.1
[text/x-patch] v20250220-0014-Implementation-of-NOT-NULL-and-IMMUTABLE-clauses.patch (33.9K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/10-v20250220-0014-Implementation-of-NOT-NULL-and-IMMUTABLE-clauses.patch)
download | inline diff:
From a0b9392f2a34b36983a1fdd6fc231fe4ced06741 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:05:06 +0100
Subject: [PATCH 14/21] Implementation of NOT NULL and IMMUTABLE clauses
Almost trivial patch - psql, pg_dump support
---
doc/src/sgml/catalogs.sgml | 20 +++
doc/src/sgml/plpgsql.sgml | 3 +-
doc/src/sgml/ref/create_variable.sgml | 32 +++-
src/backend/catalog/pg_variable.c | 8 +
src/backend/commands/session_variable.c | 69 ++++++++-
src/backend/parser/gram.y | 41 +++--
src/bin/pg_dump/pg_dump.c | 19 ++-
src/bin/pg_dump/pg_dump.h | 2 +
src/bin/pg_dump/t/002_pg_dump.pl | 36 +++++
src/bin/psql/describe.c | 6 +-
src/bin/psql/tab-complete.in.c | 12 +-
src/include/catalog/pg_variable.h | 6 +
src/include/nodes/parsenodes.h | 2 +
src/test/regress/expected/psql.out | 36 ++---
.../regress/expected/session_variables.out | 145 ++++++++++++++++++
src/test/regress/sql/session_variables.sql | 122 +++++++++++++++
16 files changed, 518 insertions(+), 41 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 27bdaf62668..c7a8170ddf2 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9867,6 +9867,26 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
<row>
<entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varnotnull</structfield> <type>boolean</type>
+ </para>
+ <para>
+ True if the session variable doesn't allow null values. The default value is false.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varisimmutable</structfield> <type>boolean</type>
+ </para>
+ <para>
+ True if the variable is <link linkend="sql-createvariable-immutable">immutable</link> (cannot be modified).
+ The default value is false.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vareoxaction</structfield> <type>char</type>
<structfield>varxactendaction</structfield> <type>char</type>
</para>
<para>
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index bfbff9ab74e..e704e05a991 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -6044,7 +6044,8 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE;
You can consider translating an Oracle package into a schema in
<productname>PostgreSQL</productname>. Package functions and procedures
would then become functions and procedures in that schema, and package
- variables could be translated to session variables in that schema.
+ variables could be translated to session variables or immutable session
+ variables in that schema.
(see <xref linkend="ddl-session-variables"/>).
</para>
</sect3>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index e4d8851ccb8..3c3e6d55b69 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -26,8 +26,8 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
- [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
+CREATE [ { TEMPORARY | TEMP } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+ [ NOT NULL ] [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -65,6 +65,22 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
<variablelist>
+ <varlistentry id="sql-createvariable-immutable">
+ <term><literal>IMMUTABLE</literal></term>
+ <listitem>
+ <para>
+ The assigned value of the session variable can not be changed.
+ Only if the session variable doesn't have a default value, a single
+ initialization is allowed using the <command>LET</command> command. Once
+ done, no further change is allowed until end of transaction
+ if the session variable was created with clause <literal>ON TRANSACTION
+ END RESET</literal>, or until reset of all session variables by
+ <command>DISCARD VARIABLES</command>, or until reset of all session
+ objects by command <command>DISCARD ALL</command>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createvariable-if-not-exists">
<term><literal>IF NOT EXISTS</literal></term>
<listitem>
@@ -105,6 +121,18 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-not-null">
+ <term><literal>NOT NULL</literal></term>
+ <listitem>
+ <para>
+ The <literal>NOT NULL</literal> clause forbids setting the session
+ variable to a null value. A session variable created as NOT NULL
+ should not to have a declared default value, and if the variable
+ has not assigned value, then the reading of this variable fails.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createvariable-default">
<term><literal>DEFAULT <replaceable>default_expr</replaceable></literal></term>
<listitem>
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 8fba4cc493b..0b6093a00ba 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -40,6 +40,8 @@ static ObjectAddress create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ bool not_null,
+ bool is_immutable,
Node *varDefexpr,
VariableXactEndAction varXactEndAction);
@@ -55,6 +57,8 @@ create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ bool not_null,
+ bool is_immutable,
Node *varDefexpr,
VariableXactEndAction varXactEndAction)
{
@@ -117,6 +121,8 @@ create_variable(const char *varName,
values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+ values[Anum_pg_variable_varnotnull - 1] = BoolGetDatum(not_null);
+ values[Anum_pg_variable_varisimmutable - 1] = BoolGetDatum(is_immutable);
values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
if (varDefexpr)
@@ -259,6 +265,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
varowner,
collation,
stmt->if_not_exists,
+ stmt->not_null,
+ stmt->is_immutable,
cooked_default,
stmt->XactEndAction);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index c12f20eaba7..95dd7445c15 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -84,6 +84,9 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ bool not_null;
+ bool is_immutable;
+
bool reset_at_eox;
/*
@@ -102,6 +105,9 @@ typedef struct SVariableData
bool is_valid;
uint32 hashvalue; /* used for pairing sinval message */
+
+ /* true, when the value is already set, and cannot be changed more */
+ bool protect_value;
} SVariableData;
typedef SVariableData *SVariable;
@@ -563,6 +569,23 @@ eval_assign_defexpr(SVariable svar, HeapTuple tup)
MemoryContextSwitchTo(oldcxt);
}
+ else
+ {
+ /*
+ * Raise an error if this is a NOT NULL variable but the result of
+ * DEFAULT expression is NULL.
+ */
+ if (svar->not_null)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("null value is not allowed for NOT NULL session variable \"%s.%s\"",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid)),
+ errdetail("The result of DEFAULT expression is NULL.")));
+ }
+
+ if (svar->is_immutable)
+ svar->protect_value = true;
FreeExecutorState(estate);
}
@@ -593,6 +616,9 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval);
+ svar->not_null = varform->varnotnull;
+ svar->is_immutable = varform->varisimmutable;
+
svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
@@ -622,9 +648,31 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
ObjectIdGetDatum(varid));
- if (!is_write)
+ svar->protect_value = false;
+
+ /*
+ * When the variable is marked as IMMUTABLE, we prefer to evaluate
+ * possible DEFAULT before write op. In this case we want to protect
+ * default value against any overwrite.
+ */
+ if (!is_write ||
+ svar->is_immutable)
+ {
eval_assign_defexpr(svar, tup);
+ /*
+ * Raise an error if this is a NOT NULL variable without default
+ * expression.
+ */
+ if (svar->isnull && svar->not_null)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("null value is not allowed for NOT NULL session variable \"%s.%s\"",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ errdetail("The session variable was not initialized yet.")));
+ }
+
ReleaseSysCache(tup);
}
@@ -644,6 +692,21 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
Assert(svar);
Assert(!isnull || value == (Datum) 0);
+ if (svar->protect_value)
+ ereport(ERROR,
+ (errcode(ERRCODE_ERROR_IN_ASSIGNMENT),
+ errmsg("session variable \"%s.%s\" is declared IMMUTABLE",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid))));
+
+ /* don't allow assignment of null to NOT NULL variable */
+ if (isnull && svar->not_null)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("null value is not allowed for NOT NULL session variable \"%s.%s\"",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid))));
+
/*
* Use typbyval, typbylen from session variable only when they are
* trustworthy (the invalidation message was not accepted for this
@@ -684,6 +747,10 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
svar->value = newval;
svar->isnull = isnull;
+
+ /* don't allow more changes of value when variable is IMMUTABLE */
+ if (svar->is_immutable)
+ svar->protect_value = true;
}
/*
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 6ee6ed43b8c..53284c0289c 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -675,6 +675,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
json_object_constructor_null_clause_opt
json_array_constructor_null_clause_opt
+%type <boolean> OptNotNull OptImmutable
/*
* Non-keyword token types. These are hard-wired into the "flex" lexer.
@@ -5265,27 +5266,31 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
+ CREATE OptTemp OptImmutable VARIABLE qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $4->relpersistence = $2;
- n->variable = $4;
- n->typeName = $6;
- n->collClause = (CollateClause *) $7;
- n->defexpr = $8;
- n->XactEndAction = $9;
+ $5->relpersistence = $2;
+ n->is_immutable = $3;
+ n->variable = $5;
+ n->typeName = $7;
+ n->collClause = (CollateClause *) $8;
+ n->not_null = $9;
+ n->defexpr = $10;
+ n->XactEndAction = $11;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
+ | CREATE OptTemp OptImmutable VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $7->relpersistence = $2;
- n->variable = $7;
- n->typeName = $9;
- n->collClause = (CollateClause *) $10;
- n->defexpr = $11;
- n->XactEndAction = $12;
+ $8->relpersistence = $2;
+ n->is_immutable = $3;
+ n->variable = $8;
+ n->typeName = $10;
+ n->collClause = (CollateClause *) $11;
+ n->not_null = $12;
+ n->defexpr = $13;
+ n->XactEndAction = $14;
n->if_not_exists = true;
$$ = (Node *) n;
}
@@ -5305,6 +5310,14 @@ XactEndActionOption: ON COMMIT DROP { $$ = VARIABLE_XACTEND_DROP; }
;
+OptNotNull: NOT NULL_P { $$ = true; }
+ | /* EMPTY */ { $$ = false; }
+ ;
+
+OptImmutable: IMMUTABLE { $$ = true; }
+ | /* EMPTY */ { $$ = false; }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 7acd793c41e..bc86e7a0fa9 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5471,6 +5471,8 @@ getVariables(Archive *fout)
int i_varxactendaction;
int i_varowner;
int i_varcollation;
+ int i_varnotnull;
+ int i_varisimmutable;
int i_varacl;
int i_acldefault;
int i,
@@ -5491,6 +5493,8 @@ getVariables(Archive *fout)
" THEN v.varcollation\n"
" ELSE 0\n"
" END AS varcollation,\n"
+ " v.varnotnull,\n"
+ " v.varisimmutable,\n"
" pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n"
" v.varowner, v.varacl,\n"
" acldefault('V', v.varowner) AS acldefault\n"
@@ -5511,6 +5515,8 @@ getVariables(Archive *fout)
i_vardefexpr = PQfnumber(res, "vardefexpr");
i_varxactendaction = PQfnumber(res, "varxactendaction");
i_varcollation = PQfnumber(res, "varcollation");
+ i_varnotnull = PQfnumber(res, "varnotnull");
+ i_varisimmutable = PQfnumber(res, "varisimmutable");
i_varowner = PQfnumber(res, "varowner");
i_varacl = PQfnumber(res, "varacl");
@@ -5537,6 +5543,8 @@ getVariables(Archive *fout)
pg_strdup(PQgetvalue(res, i, i_varxactendaction));
varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
+ varinfo[i].varnotnull = *(PQgetvalue(res, i, i_varnotnull)) == 't';
+ varinfo[i].varisimmutable = *(PQgetvalue(res, i, i_varisimmutable)) == 't';
varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
@@ -5583,7 +5591,9 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
const char *vartypname;
const char *vardefexpr;
const char *varxactendaction;
+ const char *varisimmutable;
Oid varcollation;
+ bool varnotnull;
/* skip if not to be dumped */
if (!varinfo->dobj.dump || !dopt->dumpSchema)
@@ -5597,12 +5607,14 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
vardefexpr = varinfo->vardefexpr;
varxactendaction = varinfo->varxactendaction;
varcollation = varinfo->varcollation;
+ varnotnull = varinfo->varnotnull;
+ varisimmutable = varinfo->varisimmutable ? "IMMUTABLE " : "";
appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
qualvarname);
- appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s",
- qualvarname, vartypname);
+ appendPQExpBuffer(query, "CREATE %sVARIABLE %s AS %s",
+ varisimmutable, qualvarname, vartypname);
if (OidIsValid(varcollation))
{
@@ -5614,6 +5626,9 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
fmtQualifiedDumpable(coll));
}
+ if (varnotnull)
+ appendPQExpBuffer(query, " NOT NULL");
+
if (vardefexpr)
appendPQExpBuffer(query, " DEFAULT %s",
vardefexpr);
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index e0355fca4a8..dad3a74c7d3 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -734,6 +734,8 @@ typedef struct _VariableInfo
char *varxactendaction;
Oid varcollation;
const char *rolname; /* name of owner, or empty string */
+ bool varnotnull;
+ bool varisimmutable;
} VariableInfo;
/*
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 50ba7fdc99c..ecf37dbe6fb 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4165,6 +4165,42 @@ my %tests = (
},
},
+ 'CREATE IMMUTABLE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE IMMUTABLE VARIABLE dump_test.variable5 AS integer',
+ regexp => qr/^
+ \QCREATE IMMUTABLE VARIABLE dump_test.variable5 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
+ 'CREATE IMMUTABLE VARIABLE test_variable NOT NULL DEFAULT' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE IMMUTABLE VARIABLE dump_test.variable7 AS integer NOT NULL DEFAULT 10',
+ regexp => qr/^
+ \QCREATE IMMUTABLE VARIABLE dump_test.variable7 AS integer NOT NULL DEFAULT 10;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 7780fc232ff..503ae160398 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5352,6 +5352,8 @@ listVariables(const char *pattern, bool verbose)
" (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
" WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
+ " NOT v.varnotnull as \"%s\",\n"
+ " NOT v.varisimmutable as \"%s\",\n"
" pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
@@ -5362,6 +5364,8 @@ listVariables(const char *pattern, bool verbose)
gettext_noop("Type"),
gettext_noop("Collation"),
gettext_noop("Owner"),
+ gettext_noop("Nullable"),
+ gettext_noop("Mutable"),
gettext_noop("Default"),
gettext_noop("Transactional end action"));
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 88f25acec0f..eee0216f396 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1287,6 +1287,8 @@ static const pgsql_thing_t words_after_create[] = {
{"FOREIGN TABLE", NULL, NULL, NULL},
{"FUNCTION", NULL, NULL, Query_for_list_of_functions},
{"GROUP", Query_for_list_of_roles},
+ {"IMMUTABLE VARIABLE", NULL, NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE IMMUTABLE
+ * VARIABLE ... */
{"INDEX", NULL, NULL, &Query_for_list_of_indexes},
{"LANGUAGE", Query_for_list_of_languages},
{"LARGE OBJECT", NULL, NULL, NULL, NULL, THING_NO_CREATE | THING_NO_DROP},
@@ -3637,7 +3639,8 @@ match_previous_words(int pattern_id,
/* CREATE TABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete "CREATE TEMP/TEMPORARY" with the possible temp objects */
else if (TailMatches("CREATE", "TEMP|TEMPORARY"))
- COMPLETE_WITH("SEQUENCE", "TABLE", "VARIABLE", "VIEW");
+ COMPLETE_WITH("IMMUTABLE VARIABLE", "SEQUENCE", "TABLE", "VARIABLE",
+ "VIEW");
/* Complete "CREATE UNLOGGED" with TABLE or SEQUENCE */
else if (TailMatches("CREATE", "UNLOGGED"))
COMPLETE_WITH("TABLE", "SEQUENCE");
@@ -3989,7 +3992,8 @@ match_previous_words(int pattern_id,
/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE VARIABLE <name> with AS */
else if (TailMatches("CREATE", "VARIABLE", MatchAny) ||
- TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny))
+ TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny) ||
+ TailMatches("IMMUTABLE", "VARIABLE", MatchAny))
COMPLETE_WITH("AS");
else if (TailMatches("VARIABLE", MatchAny, "AS"))
/* Complete CREATE VARIABLE <name> with AS types */
@@ -4649,6 +4653,10 @@ match_previous_words(int pattern_id,
else if (TailMatches("FROM", "SERVER", MatchAny, "INTO", MatchAny))
COMPLETE_WITH("OPTIONS (");
+/* IMMUTABLE -- can be expend to IMMUTABLE VARIABLE */
+ else if (TailMatches("CREATE", "IMMUTABLE"))
+ COMPLETE_WITH("VARIABLE");
+
/* INSERT --- can be inside EXPLAIN, RULE, etc */
/* Complete NOT MATCHED THEN INSERT */
else if (TailMatches("NOT", "MATCHED", "THEN", "INSERT"))
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 09dd44a44e1..cf21e0426a7 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -56,6 +56,12 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* typmod for variable's type */
int32 vartypmod BKI_DEFAULT(-1);
+ /* don't allow NULL */
+ bool varnotnull BKI_DEFAULT(f);
+
+ /* don't allow changes */
+ bool varisimmutable BKI_DEFAULT(f);
+
/* action on transaction end */
char varxactendaction BKI_DEFAULT(n);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 67ef92685fd..785354ab52c 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3546,6 +3546,8 @@ typedef struct CreateSessionVarStmt
TypeName *typeName; /* the type of variable */
CollateClause *collClause;
bool if_not_exists; /* do nothing if it already exists */
+ bool not_null; /* disallow nulls */
+ bool is_immutable; /* don't allow changes */
Node *defexpr; /* default expression */
char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 999fc88d1e1..78aca67e452 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6020,20 +6020,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+---------+--------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | | | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+---------+--------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | | | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6501,9 +6501,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action
---------+------+------+-----------+-------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6676,9 +6676,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action
---------+------+------+-----------+-------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6815,9 +6815,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action
---------+------+------+-----------+-------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 5640875dc59..548c0e3bcd2 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2362,3 +2362,148 @@ SELECT var1;
DROP VARIABLE var1;
DROP FUNCTION vartest_fx();
+-- test NOT NULL
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL;
+-- should to fail
+SELECT var1;
+ERROR: null value is not allowed for NOT NULL session variable "public.var1"
+DETAIL: The session variable was not initialized yet.
+--should be ok
+LET var1 = 10;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1;
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT 0;
+--should be ok
+SELECT var1;
+ var1
+------
+ 0
+(1 row)
+
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DISCARD VARIABLES;
+-- should to fail
+LET var1 = NULL;
+ERROR: null value is not allowed for NOT NULL session variable "public.var1"
+DROP VARIABLE var1;
+-- test NOT NULL
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN NULL;
+END;
+$$ LANGUAGE plpgsql;
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT vartest_fx();
+-- should to fail
+SELECT var1;
+ERROR: null value is not allowed for NOT NULL session variable "public.var1"
+DETAIL: The result of DEFAULT expression is NULL.
+DISCARD VARIABLES;
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+DISCARD VARIABLES;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 0
+(1 row)
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
+-- test IMMUTBLE
+CREATE IMMUTABLE VARIABLE var1 AS int;
+-- should be ok
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+-- first write should ok
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DISCARD VARIABLES;
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DISCARD VARIABLES;
+-- should be ok
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+-- should be ok
+LET var1 = NULL;
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DROP VARIABLE var1;
+CREATE IMMUTABLE VARIABLE var1 AS int DEFAULT 10;
+-- don't allow change when variable has DEFAULT value
+-- should to fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DISCARD VARIABLES;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DROP VARIABLE var1;
+-- should be ok
+CREATE IMMUTABLE VARIABLE var1 AS INT NOT NULL DEFAULT 10;
+-- should to fail
+LET var1 = 10;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- should to fail
+LET var1 = 30;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DROP VARIABLE var1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 2c7388639d9..282ba5c8639 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1613,3 +1613,125 @@ SELECT var1;
DROP VARIABLE var1;
DROP FUNCTION vartest_fx();
+
+-- test NOT NULL
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL;
+-- should to fail
+SELECT var1;
+
+--should be ok
+LET var1 = 10;
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT 0;
+
+--should be ok
+SELECT var1;
+
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+
+DISCARD VARIABLES;
+
+-- should to fail
+LET var1 = NULL;
+
+DROP VARIABLE var1;
+
+-- test NOT NULL
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN NULL;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT vartest_fx();
+
+-- should to fail
+SELECT var1;
+
+DISCARD VARIABLES;
+
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+
+DISCARD VARIABLES;
+
+-- should be ok
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
+
+-- test IMMUTBLE
+CREATE IMMUTABLE VARIABLE var1 AS int;
+
+-- should be ok
+SELECT var1;
+-- first write should ok
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+
+DISCARD VARIABLES;
+
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+
+DISCARD VARIABLES;
+
+-- should be ok
+SELECT var1;
+-- should be ok
+LET var1 = NULL;
+-- should fail
+LET var1 = 20;
+
+DROP VARIABLE var1;
+
+CREATE IMMUTABLE VARIABLE var1 AS int DEFAULT 10;
+
+-- don't allow change when variable has DEFAULT value
+-- should to fail
+LET var1 = 20;
+
+DISCARD VARIABLES;
+
+-- should be ok
+SELECT var1;
+-- should fail
+LET var1 = 20;
+
+DROP VARIABLE var1;
+
+-- should be ok
+CREATE IMMUTABLE VARIABLE var1 AS INT NOT NULL DEFAULT 10;
+
+-- should to fail
+LET var1 = 10;
+LET var1 = 20;
+
+-- should be ok
+SELECT var1;
+
+-- should to fail
+LET var1 = 30;
+
+DROP VARIABLE var1;
--
2.48.1
[text/x-patch] v20250220-0013-Implementation-of-DEFAULT-clause-default-expressions.patch (32.1K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/11-v20250220-0013-Implementation-of-DEFAULT-clause-default-expressions.patch)
download | inline diff:
From 2b101a2ef0c60d92b944871223c65cf95b6bebf1 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:03:53 +0100
Subject: [PATCH 13/21] Implementation of DEFAULT clause - default expressions
for session variables
When the evaluation of default expression fails, we remove related entry from sessionvars
hash table. Then sessionvars can contain only sucessfully initialized values. Then we don't
need special flag for badly initialized session variables.
---
doc/src/sgml/catalogs.sgml | 8 ++
doc/src/sgml/ddl.sgml | 16 ++--
doc/src/sgml/ref/create_variable.sgml | 21 +++--
doc/src/sgml/ref/discard.sgml | 3 +-
src/backend/catalog/pg_variable.c | 27 ++++++
src/backend/commands/session_variable.c | 87 ++++++++++++++++++-
src/backend/parser/gram.y | 15 +++-
src/backend/parser/parse_agg.c | 2 +
src/backend/parser/parse_expr.c | 4 +
src/backend/parser/parse_func.c | 1 +
src/bin/pg_dump/pg_dump.c | 14 +++
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_dump/t/002_pg_dump.pl | 36 ++++++++
src/bin/psql/describe.c | 4 +-
src/include/catalog/pg_variable.h | 3 +
src/include/nodes/parsenodes.h | 1 +
src/include/parser/parse_node.h | 1 +
src/test/regress/expected/psql.out | 36 ++++----
.../regress/expected/session_variables.out | 63 ++++++++++++++
src/test/regress/sql/session_variables.sql | 48 ++++++++++
20 files changed, 350 insertions(+), 41 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 687d1c8733a..27bdaf62668 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9899,6 +9899,14 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vardefexpr</structfield> <type>pg_node_tree</type>
+ </para>
+ <para>
+ The internal representation of the variable default value
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 3e2cb3c46eb..4c6988540e8 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5407,14 +5407,14 @@ SELECT current_user_id;
<para>
The value of a session variable is local to the current session. Retrieving
- a variable's value returns a <literal>NULL</literal>, unless its value has
- been set to something else in the current session using the
- <command>LET</command> command. Session variables are not transactional:
- any changes made to the value of a session variable in a transaction won't
- be undone if the transaction is rolled back (just like variables in
- procedural languages). Session variables themselves can be persistent
- or temporary, but their values are neither persistent nor shared (like the
- content of temporary tables).
+ a variable's value returns a <literal>NULL</literal> or a default value,
+ unless its value has been set to something else in the current session
+ using the <command>LET</command> command. Session variables are not
+ transactional: any changes made to the value of a session variable in
+ a transaction won't be undone if the transaction is rolled back (just like
+ variables in procedural languages). Session variables themselves can be
+ persistent or temporary, but their values are neither persistent nor shared
+ (like the content of temporary tables).
</para>
<para>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index c89a65fb55f..e4d8851ccb8 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -27,7 +27,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
- [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
+ [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -41,10 +41,10 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
<para>
The value of a session variable is local to the current session. Retrieving
- a session variable's value returns NULL, unless its value is set to
- something else in the current session with a <command>LET</command> command.
- The content of a session variable is not transactional. This is the same as
- regular variables in procedural languages.
+ a session variable's value returns NULL or a default value, unless its value
+ is set to something else in the current session with a <command>LET</command>
+ command. The content of a session variable is not transactional. This is the
+ same as regular variables in procedural languages.
</para>
<para>
@@ -105,6 +105,17 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-default">
+ <term><literal>DEFAULT <replaceable>default_expr</replaceable></literal></term>
+ <listitem>
+ <para>
+ The <literal>DEFAULT</literal> clause can be used to assign a default
+ value to a session variable. This expression is evaluated when the session
+ variable is first accessed for reading and had not yet been assigned a value.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createvariable-on-commit-drop">
<term><literal>ON COMMIT DROP</literal></term>
<listitem>
diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
index 61b967f9c9b..6b0cb95034f 100644
--- a/doc/src/sgml/ref/discard.sgml
+++ b/doc/src/sgml/ref/discard.sgml
@@ -71,7 +71,8 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES }
<listitem>
<para>
Resets the value of all session variables. If a variable
- is later reused, it is re-initialized to <literal>NULL</literal>.
+ is later reused, it is re-initialized to either
+ <literal>NULL</literal> or its default value.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 00c90ea6fd8..8fba4cc493b 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -24,6 +24,9 @@
#include "catalog/pg_variable.h"
#include "commands/session_variable.h"
#include "miscadmin.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_collate.h"
+#include "parser/parse_expr.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
@@ -37,6 +40,7 @@ static ObjectAddress create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ Node *varDefexpr,
VariableXactEndAction varXactEndAction);
@@ -51,6 +55,7 @@ create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ Node *varDefexpr,
VariableXactEndAction varXactEndAction)
{
Acl *varacl;
@@ -114,6 +119,11 @@ create_variable(const char *varName,
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
+ if (varDefexpr)
+ values[Anum_pg_variable_vardefexpr - 1] = CStringGetTextDatum(nodeToString(varDefexpr));
+ else
+ nulls[Anum_pg_variable_vardefexpr - 1] = true;
+
varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
varNamespace);
if (varacl != NULL)
@@ -150,6 +160,11 @@ create_variable(const char *varName,
record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
free_object_addresses(addrs);
+ /* dependency on default expr */
+ if (varDefexpr)
+ recordDependencyOnExpr(&myself, (Node *) varDefexpr,
+ NIL, DEPENDENCY_NORMAL);
+
/* dependency on owner */
recordDependencyOnOwner(VariableRelationId, varid, varOwner);
@@ -185,6 +200,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
Oid collation;
Oid typcollation;
ObjectAddress variable;
+ Node *cooked_default = NULL;
/* check consistency of arguments */
if (stmt->XactEndAction == VARIABLE_XACTEND_DROP
@@ -226,6 +242,16 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
format_type_be(typid)),
parser_errposition(pstate, stmt->collClause->location)));
+ if (stmt->defexpr)
+ {
+ cooked_default = transformExpr(pstate, stmt->defexpr,
+ EXPR_KIND_VARIABLE_DEFAULT);
+
+ cooked_default = coerce_to_specific_type(pstate,
+ cooked_default, typid, "DEFAULT");
+ assign_expr_collations(pstate, cooked_default);
+ }
+
variable = create_variable(stmt->variable->relname,
namespaceid,
typid,
@@ -233,6 +259,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
varowner,
collation,
stmt->if_not_exists,
+ cooked_default,
stmt->XactEndAction);
elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index f12c20c849f..c12f20eaba7 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -22,6 +22,7 @@
#include "executor/svariableReceiver.h"
#include "funcapi.h"
#include "miscadmin.h"
+#include "optimizer/optimizer.h"
#include "rewrite/rewriteHandler.h"
#include "storage/lmgr.h"
#include "storage/proc.h"
@@ -510,11 +511,68 @@ AtEOSubXact_SessionVariables(bool isCommit,
}
}
+/*
+ * evaluate an expression
+ */
+static void
+eval_assign_defexpr(SVariable svar, HeapTuple tup)
+{
+ Datum defexpr_value;
+ bool isnull;
+
+ Assert(svar);
+ Assert(svar->is_valid);
+ Assert(HeapTupleIsValid(tup));
+
+ defexpr_value = SysCacheGetAttr(VARIABLEOID,
+ tup,
+ Anum_pg_variable_vardefexpr,
+ &isnull);
+
+ if (!isnull)
+ {
+ EState *estate;
+ ExprState *defexprs;
+ Expr *defexpr;
+ char *defexpr_str;
+ Datum value;
+ MemoryContext oldcxt;
+
+ estate = CreateExecutorState();
+
+ defexpr_str = TextDatumGetCString(defexpr_value);
+ defexpr = (Expr *) stringToNode(defexpr_str);
+
+ oldcxt = MemoryContextSwitchTo(estate->es_query_cxt);
+
+ defexpr = expression_planner((Expr *) defexpr);
+ defexprs = ExecInitExpr(defexpr, NULL);
+
+ value = ExecEvalExprSwitchContext(defexprs,
+ GetPerTupleExprContext(estate),
+ &isnull);
+
+ MemoryContextSwitchTo(oldcxt);
+
+ if (!isnull)
+ {
+ oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
+
+ svar->value = datumCopy(value, svar->typbyval, svar->typlen);
+ svar->isnull = false;
+
+ MemoryContextSwitchTo(oldcxt);
+ }
+
+ FreeExecutorState(estate);
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
static void
-setup_session_variable(SVariable svar, Oid varid)
+setup_session_variable(SVariable svar, Oid varid, bool is_write)
{
HeapTuple tup;
Form_pg_variable varform;
@@ -564,6 +622,9 @@ setup_session_variable(SVariable svar, Oid varid)
svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
ObjectIdGetDatum(varid));
+ if (!is_write)
+ eval_assign_defexpr(svar, tup);
+
ReleaseSysCache(tup);
}
@@ -593,7 +654,7 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
*/
if (!svar->is_valid)
{
- setup_session_variable(&locsvar, svar->varid);
+ setup_session_variable(&locsvar, svar->varid, false);
_svar = &locsvar;
}
else
@@ -726,7 +787,25 @@ get_session_variable(Oid varid)
*/
if (!svar->is_valid)
{
- setup_session_variable(svar, varid);
+ /* in this case we want to use defexp if it is defined */
+ PG_TRY();
+ {
+ /*
+ * In this case, the setup can execute default expression. When
+ * the execution of default expression fails, then we need to
+ * remove entry from session vars.
+ */
+ setup_session_variable(svar, varid, false);
+ }
+ PG_CATCH();
+ {
+ /* this entry cannot be valid, remove from sessionvars */
+ hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
+
+ /* propagate the error */
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)",
get_namespace_name(get_session_variable_namespace(varid)),
@@ -790,7 +869,7 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
if (!found)
{
- setup_session_variable(svar, varid);
+ setup_session_variable(svar, varid, true);
elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)",
get_namespace_name(get_session_variable_namespace(svar->varid)),
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index fb8cc863748..6ee6ed43b8c 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -645,6 +645,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <partboundspec> PartitionBoundSpec
%type <list> hash_partbound
%type <defelt> hash_partbound_elem
+%type <node> OptSessionVarDefExpr
%type <node> json_format_clause
json_format_clause_opt
@@ -5264,30 +5265,36 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause XactEndActionOption
+ CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
$4->relpersistence = $2;
n->variable = $4;
n->typeName = $6;
n->collClause = (CollateClause *) $7;
- n->XactEndAction = $8;
+ n->defexpr = $8;
+ n->XactEndAction = $9;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause XactEndActionOption
+ | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
$7->relpersistence = $2;
n->variable = $7;
n->typeName = $9;
n->collClause = (CollateClause *) $10;
- n->XactEndAction = $11;
+ n->defexpr = $11;
+ n->XactEndAction = $12;
n->if_not_exists = true;
$$ = (Node *) n;
}
;
+OptSessionVarDefExpr: DEFAULT b_expr { $$ = $2; }
+ | /* EMPTY */ { $$ = NULL; }
+ ;
+
/*
* Temporary session variables can be dropped on successful
* transaction end like tables.
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 4737b04d171..54b765c8eb5 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -488,6 +488,7 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
if (isAgg)
err = _("aggregate functions are not allowed in DEFAULT expressions");
@@ -937,6 +938,7 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
err = _("window functions are not allowed in DEFAULT expressions");
break;
case EXPR_KIND_INDEX_EXPRESSION:
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index dd03b1f14db..158a67be523 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -588,6 +588,7 @@ expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
case EXPR_KIND_JOIN_USING:
case EXPR_KIND_CYCLE_MARK:
case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_VARIABLE_DEFAULT:
result = false;
break;
}
@@ -673,6 +674,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
case EXPR_KIND_CYCLE_MARK:
case EXPR_KIND_ASSIGN_TARGET:
case EXPR_KIND_LET_TARGET:
+ case EXPR_KIND_VARIABLE_DEFAULT:
/* okay */
break;
@@ -2146,6 +2148,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
err = _("cannot use subquery in DEFAULT expression");
break;
case EXPR_KIND_INDEX_EXPRESSION:
@@ -3508,6 +3511,7 @@ ParseExprKindName(ParseExprKind exprKind)
return "CHECK";
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
return "DEFAULT";
case EXPR_KIND_INDEX_EXPRESSION:
return "index expression";
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index dc25f6dcd0e..d9f15c2618f 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2620,6 +2620,7 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location)
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
err = _("set-returning functions are not allowed in DEFAULT expressions");
break;
case EXPR_KIND_INDEX_EXPRESSION:
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 88ebdff0b06..7acd793c41e 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5467,6 +5467,7 @@ getVariables(Archive *fout)
int i_varnamespace;
int i_vartype;
int i_vartypname;
+ int i_vardefexpr;
int i_varxactendaction;
int i_varowner;
int i_varcollation;
@@ -5490,6 +5491,7 @@ getVariables(Archive *fout)
" THEN v.varcollation\n"
" ELSE 0\n"
" END AS varcollation,\n"
+ " pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n"
" v.varowner, v.varacl,\n"
" acldefault('V', v.varowner) AS acldefault\n"
"FROM pg_catalog.pg_variable v\n"
@@ -5506,6 +5508,7 @@ getVariables(Archive *fout)
i_varnamespace = PQfnumber(res, "varnamespace");
i_vartype = PQfnumber(res, "vartype");
i_vartypname = PQfnumber(res, "vartypname");
+ i_vardefexpr = PQfnumber(res, "vardefexpr");
i_varxactendaction = PQfnumber(res, "varxactendaction");
i_varcollation = PQfnumber(res, "varcollation");
@@ -5541,6 +5544,11 @@ getVariables(Archive *fout)
varinfo[i].dacl.initprivs = NULL;
varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner));
+ if (PQgetisnull(res, i, i_vardefexpr))
+ varinfo[i].vardefexpr = NULL;
+ else
+ varinfo[i].vardefexpr = pg_strdup(PQgetvalue(res, i, i_vardefexpr));
+
/* do not try to dump ACL if no ACL exists */
if (!PQgetisnull(res, i, i_varacl))
varinfo[i].dobj.components |= DUMP_COMPONENT_ACL;
@@ -5573,6 +5581,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
PQExpBuffer query;
char *qualvarname;
const char *vartypname;
+ const char *vardefexpr;
const char *varxactendaction;
Oid varcollation;
@@ -5585,6 +5594,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
vartypname = varinfo->vartypname;
+ vardefexpr = varinfo->vardefexpr;
varxactendaction = varinfo->varxactendaction;
varcollation = varinfo->varcollation;
@@ -5604,6 +5614,10 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
fmtQualifiedDumpable(coll));
}
+ if (vardefexpr)
+ appendPQExpBuffer(query, " DEFAULT %s",
+ vardefexpr);
+
if (strcmp(varxactendaction, "r") == 0)
appendPQExpBuffer(query, " ON TRANSACTION END RESET");
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index 8224d10f3b3..e0355fca4a8 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -730,6 +730,7 @@ typedef struct _VariableInfo
DumpableAcl dacl;
Oid vartype;
char *vartypname;
+ char *vardefexpr;
char *varxactendaction;
Oid varcollation;
const char *rolname; /* name of owner, or empty string */
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index ac5ec8a4d84..50ba7fdc99c 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4129,6 +4129,42 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable DEFAULT' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable3 AS integer DEFAULT 10;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable3 AS integer DEFAULT 10;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
+ 'CREATE VARIABLE test_variable DEFAULT ON TRANSACTION END RESET' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable4 AS integer DEFAULT 10 ON TRANSACTION END RESET',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable4 AS integer DEFAULT 10 ON TRANSACTION END RESET;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a84222b7762..7780fc232ff 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5352,6 +5352,7 @@ listVariables(const char *pattern, bool verbose)
" (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
" WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
+ " pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
" WHEN 'r' THEN 'ON TRANSACTION END RESET'\n"
@@ -5361,6 +5362,7 @@ listVariables(const char *pattern, bool verbose)
gettext_noop("Type"),
gettext_noop("Collation"),
gettext_noop("Owner"),
+ gettext_noop("Default"),
gettext_noop("Transactional end action"));
if (verbose)
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 008f2ee7c17..09dd44a44e1 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -68,6 +68,9 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* access permissions */
aclitem varacl[1] BKI_DEFAULT(_null_);
+ /* list of expression trees for variable default (NULL if none) */
+ pg_node_tree vardefexpr BKI_DEFAULT(_null_);
+
#endif
} FormData_pg_variable;
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 2e4d9ab5f47..67ef92685fd 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3546,6 +3546,7 @@ typedef struct CreateSessionVarStmt
TypeName *typeName; /* the type of variable */
CollateClause *collClause;
bool if_not_exists; /* do nothing if it already exists */
+ Node *defexpr; /* default expression */
char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 0b7b69a4159..6b55cc8308b 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -84,6 +84,7 @@ typedef enum ParseExprKind
EXPR_KIND_CYCLE_MARK, /* cycle mark value */
EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */
EXPR_KIND_LET_TARGET, /* LET target */
+ EXPR_KIND_VARIABLE_DEFAULT, /* default value for session variable */
} ParseExprKind;
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 3ddbcc7cc2a..999fc88d1e1 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6020,20 +6020,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+--------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+---------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+--------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+---------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6501,9 +6501,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action
---------+------+------+-----------+-------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action
+--------+------+------+-----------+-------+---------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6676,9 +6676,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action
---------+------+------+-----------+-------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action
+--------+------+------+-----------+-------+---------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6815,9 +6815,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action
---------+------+------+-----------+-------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action
+--------+------+------+-----------+-------+---------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7b3ed43618f..5640875dc59 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2299,3 +2299,66 @@ SELECT var1 IS NULL;
(1 row)
DROP VARIABLE var1;
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE NOTICE 'vartest_fx executed';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+CREATE VARIABLE var1 AS int DEFAULT vartest_fx();
+-- vartest_fx should be protected by dep, should fail
+DROP FUNCTION vartest_fx();
+ERROR: cannot drop function vartest_fx() because other objects depend on it
+DETAIL: session variable var1 depends on function vartest_fx()
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+SELECT var1;
+NOTICE: vartest_fx executed
+ var1
+------
+ 0
+(1 row)
+
+-- the defexpr should be evaluated only once
+SELECT var1;
+ var1
+------
+ 0
+(1 row)
+
+DISCARD VARIABLES;
+-- in this case, the defexpr should not be evaluated
+LET var1 = 100;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DISCARD VARIABLES;
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE EXCEPTION 'vartest_fx is executing';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+-- should to fail, but not to crash
+SELECT var1;
+ERROR: vartest_fx is executing
+CONTEXT: PL/pgSQL function vartest_fx() line 3 at RAISE
+-- again
+SELECT var1;
+ERROR: vartest_fx is executing
+CONTEXT: PL/pgSQL function vartest_fx() line 3 at RAISE
+-- but we can write
+LET var1 = 100;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index d6e7c21bf16..2c7388639d9 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1565,3 +1565,51 @@ ROLLBACK;
SELECT var1 IS NULL;
DROP VARIABLE var1;
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE NOTICE 'vartest_fx executed';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE VARIABLE var1 AS int DEFAULT vartest_fx();
+
+-- vartest_fx should be protected by dep, should fail
+DROP FUNCTION vartest_fx();
+
+-- should be ok
+SELECT var1;
+
+-- the defexpr should be evaluated only once
+SELECT var1;
+
+DISCARD VARIABLES;
+
+-- in this case, the defexpr should not be evaluated
+LET var1 = 100;
+SELECT var1;
+
+DISCARD VARIABLES;
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE EXCEPTION 'vartest_fx is executing';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+
+-- should to fail, but not to crash
+SELECT var1;
+
+-- again
+SELECT var1;
+
+-- but we can write
+LET var1 = 100;
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
--
2.48.1
[text/x-patch] v20250220-0012-Implementation-ON-TRANSACTION-END-RESET-clause.patch (14.6K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/12-v20250220-0012-Implementation-ON-TRANSACTION-END-RESET-clause.patch)
download | inline diff:
From 039be21334f8fd804a9adda5e1c69ece91b52ef6 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:02:13 +0100
Subject: [PATCH 12/21] Implementation ON TRANSACTION END RESET clause
This is simple patch - just add special flag to session variable memory entry.
The entries with active this flag are removed from sessionvars hash table
at transaction end. The "TRANSACTION END" is synonyms for "COMMIT ROLLBACK"
but the "TRANSACTION END" is more illustrative and less confusing then "COMMIT ROLLBACK".
---
doc/src/sgml/catalogs.sgml | 3 +-
doc/src/sgml/ref/create_variable.sgml | 13 ++++-
src/backend/commands/session_variable.c | 51 +++++++++++++++++++
src/backend/parser/gram.y | 1 +
src/bin/pg_dump/pg_dump.c | 11 ++++
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_dump/t/002_pg_dump.pl | 18 +++++++
src/bin/psql/describe.c | 1 +
src/include/catalog/pg_variable.h | 1 +
.../isolation/expected/session-variable.out | 4 +-
.../isolation/specs/session-variable.spec | 4 +-
.../regress/expected/session_variables.out | 34 +++++++++++++
src/test/regress/sql/session_variables.sql | 20 ++++++++
13 files changed, 158 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 09b635c234a..687d1c8733a 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9871,7 +9871,8 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para>
<para>
Action performed at end of transaction:
- <literal>n</literal> = no action, <literal>d</literal> = drop the variable.
+ <literal>n</literal> = no action, <literal>d</literal> = drop the variable,
+ <literal>r</literal> = reset the variable to its default value.
</para></entry>
</row>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index a88e0175bea..c89a65fb55f 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -27,7 +27,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
- [ ON COMMIT DROP ]
+ [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -117,6 +117,17 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-on-transaction-end-reset">
+ <term><literal>ON TRANSACTION END RESET</literal></term>
+ <listitem>
+ <para>
+ The <literal>ON TRANSACTION END RESET</literal> clause causes the session
+ variable to be reset to its default value when the transaction is committed
+ or rolled back.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</refsect1>
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index dc51a778bf5..f12c20c849f 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -83,6 +83,8 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ bool reset_at_eox;
+
/*
* Top level local transaction id of the last transaction that dropped the
* variable, if any. We need this information to avoid freeing memory for
@@ -110,6 +112,12 @@ static MemoryContext SVariableMemoryContext = NULL;
/* becomes true when we receive a sinval message */
static bool needs_validation = false;
+/*
+ * true, when some used session variable has ON COMMIT DROP
+ * or ON TRANSACTION END RESET clauses
+ */
+static bool has_session_variables_with_reset_at_eox = false;
+
/*
* The content of dropped session variables is not removed immediately. If
* possible, we do that at the end of the transaction. But we cannot do that
@@ -385,6 +393,32 @@ remove_invalid_session_variables(bool atEOX)
}
}
+/*
+ * remove entries marked as "reset_at_eox"
+ */
+static void
+remove_session_variables_with_reset_at_eox(void)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ if (!sessionvars)
+ return;
+
+ /* leave quckly, when there are not that variables */
+ if (!has_session_variables_with_reset_at_eox)
+ return;
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (svar->reset_at_eox)
+ hash_search(sessionvars, &svar->varid, HASH_REMOVE, NULL);
+ }
+
+ has_session_variables_with_reset_at_eox = false;
+}
+
/*
* Perform ON COMMIT DROP for temporary session variables,
* and remove all dropped variables from memory.
@@ -392,6 +426,8 @@ remove_invalid_session_variables(bool atEOX)
void
AtPreEOXact_SessionVariables(bool isCommit)
{
+ remove_session_variables_with_reset_at_eox();
+
if (isCommit)
{
if (xact_drop_items)
@@ -503,6 +539,21 @@ setup_session_variable(SVariable svar, Oid varid)
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+ /*
+ * We don't need to explicitly reset variables marked ON COMMIT DROP. It
+ * can be done by sinval message processing. But this processing can be
+ * postponed due aborted transaction. On second hand there is not a
+ * reason, why don't do it at transaction end immediately.
+ */
+ if (varform->varxactendaction == VARIABLE_XACTEND_RESET ||
+ varform->varxactendaction == VARIABLE_XACTEND_DROP)
+ {
+ svar->reset_at_eox = true;
+ has_session_variables_with_reset_at_eox = true;
+ }
+ else
+ svar->reset_at_eox = false;
+
svar->drop_lxid = InvalidTransactionId;
svar->isnull = true;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 4072c155b56..fb8cc863748 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -5293,6 +5293,7 @@ CreateSessionVarStmt:
* transaction end like tables.
*/
XactEndActionOption: ON COMMIT DROP { $$ = VARIABLE_XACTEND_DROP; }
+ | ON TRANSACTION END_P RESET { $$ = VARIABLE_XACTEND_RESET; }
| /*EMPTY*/ { $$ = VARIABLE_XACTEND_NOOP; }
;
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 8631ba6b68c..88ebdff0b06 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5467,6 +5467,7 @@ getVariables(Archive *fout)
int i_varnamespace;
int i_vartype;
int i_vartypname;
+ int i_varxactendaction;
int i_varowner;
int i_varcollation;
int i_varacl;
@@ -5482,6 +5483,7 @@ getVariables(Archive *fout)
/* get the variables in current database */
appendPQExpBuffer(query,
"SELECT v.tableoid, v.oid, v.varname,\n"
+ " v.varxactendaction,\n"
" v.varnamespace, v.vartype,\n"
" pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n"
" CASE WHEN v.varcollation <> t.typcollation "
@@ -5504,6 +5506,7 @@ getVariables(Archive *fout)
i_varnamespace = PQfnumber(res, "varnamespace");
i_vartype = PQfnumber(res, "vartype");
i_vartypname = PQfnumber(res, "vartypname");
+ i_varxactendaction = PQfnumber(res, "varxactendaction");
i_varcollation = PQfnumber(res, "varcollation");
i_varowner = PQfnumber(res, "varowner");
@@ -5527,6 +5530,9 @@ getVariables(Archive *fout)
varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype));
varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname));
+ varinfo[i].varxactendaction =
+ pg_strdup(PQgetvalue(res, i, i_varxactendaction));
+
varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
@@ -5567,6 +5573,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
PQExpBuffer query;
char *qualvarname;
const char *vartypname;
+ const char *varxactendaction;
Oid varcollation;
/* skip if not to be dumped */
@@ -5578,6 +5585,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
vartypname = varinfo->vartypname;
+ varxactendaction = varinfo->varxactendaction;
varcollation = varinfo->varcollation;
appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
@@ -5596,6 +5604,9 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
fmtQualifiedDumpable(coll));
}
+ if (strcmp(varxactendaction, "r") == 0)
+ appendPQExpBuffer(query, " ON TRANSACTION END RESET");
+
appendPQExpBuffer(query, ";\n");
if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index cc27357478f..8224d10f3b3 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -730,6 +730,7 @@ typedef struct _VariableInfo
DumpableAcl dacl;
Oid vartype;
char *vartypname;
+ char *varxactendaction;
Oid varcollation;
const char *rolname; /* name of owner, or empty string */
} VariableInfo;
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index a5086e1becd..ac5ec8a4d84 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4111,6 +4111,24 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable ON TRANSACTION END RESET' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable2 AS integer ON TRANSACTION END RESET;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable2 AS integer ON TRANSACTION END RESET;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 50ddcc24140..a84222b7762 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5354,6 +5354,7 @@ listVariables(const char *pattern, bool verbose)
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
+ " WHEN 'r' THEN 'ON TRANSACTION END RESET'\n"
" END as \"%s\"\n",
gettext_noop("Schema"),
gettext_noop("Name"),
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 0fc672bc2ba..008f2ee7c17 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -75,6 +75,7 @@ typedef enum VariableXactEndAction
{
VARIABLE_XACTEND_NOOP = 'n', /* NOOP */
VARIABLE_XACTEND_DROP = 'd', /* ON COMMIT DROP */
+ VARIABLE_XACTEND_RESET = 'r', /* ON TRANSACTION END RESET */
} VariableXactEndAction;
/* ----------------
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
index a609797dc5d..e9a254bcd12 100644
--- a/src/test/isolation/expected/session-variable.out
+++ b/src/test/isolation/expected/session-variable.out
@@ -86,11 +86,12 @@ myvar
step sr1: ROLLBACK;
-starting permutation: create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
+starting permutation: create3 let3 s3 o_c_d o_eox_r create4 let4 drop4 drop3 inval3 discard sc3 clean state
step create3: CREATE VARIABLE myvar3 AS text;
step let3: LET myvar3 = 'test';
step s3: BEGIN;
step o_c_d: CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP;
+step o_eox_r: CREATE VARIABLE myvar_o_eox_r AS text ON TRANSACTION END RESET; LET myvar_o_eox_r = 'test';
step create4: CREATE VARIABLE myvar4 AS text;
step let4: LET myvar4 = 'test';
step drop4: DROP VARIABLE myvar4;
@@ -103,6 +104,7 @@ t
step discard: DISCARD VARIABLES;
step sc3: COMMIT;
+step clean: DROP VARIABLE myvar_o_eox_r;
step state: SELECT varname FROM pg_variable;
varname
-------
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
index 45e65d4085d..5d089c8a4ed 100644
--- a/src/test/isolation/specs/session-variable.spec
+++ b/src/test/isolation/specs/session-variable.spec
@@ -25,12 +25,14 @@ session s3
step s3 { BEGIN; }
step let3 { LET myvar3 = 'test'; }
step o_c_d { CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP; }
+step o_eox_r { CREATE VARIABLE myvar_o_eox_r AS text ON TRANSACTION END RESET; LET myvar_o_eox_r = 'test'; }
step create4 { CREATE VARIABLE myvar4 AS text; }
step let4 { LET myvar4 = 'test'; }
step drop4 { DROP VARIABLE myvar4; }
step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; }
step discard { DISCARD VARIABLES; }
step sc3 { COMMIT; }
+step clean { DROP VARIABLE myvar_o_eox_r; }
step state { SELECT varname FROM pg_variable; }
session s4
@@ -48,4 +50,4 @@ permutation let val dbg drop create dbg val
# calling the dbg step after the concurrent drop
permutation let val s1 dbg drop create dbg val sr1
# test for DISCARD ALL when all internal queues have actions registered
-permutation create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
+permutation create3 let3 s3 o_c_d o_eox_r create4 let4 drop4 drop3 inval3 discard sc3 clean state
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 14e093eb8a7..7b3ed43618f 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2265,3 +2265,37 @@ SELECT count(*) FROM pg_session_variables();
0
(1 row)
+CREATE VARIABLE var1 AS int ON TRANSACTION END RESET;
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+COMMIT;
+-- should be NULL;
+SELECT var1 IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be NULL
+SELECT var1 IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+DROP VARIABLE var1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index e6ccc37153d..d6e7c21bf16 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1545,3 +1545,23 @@ COMMIT;
SELECT count(*) FROM pg_variable WHERE varname = 'var1';
-- should be zero
SELECT count(*) FROM pg_session_variables();
+
+CREATE VARIABLE var1 AS int ON TRANSACTION END RESET;
+
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+COMMIT;
+
+-- should be NULL;
+SELECT var1 IS NULL;
+
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+ROLLBACK;
+
+-- should be NULL
+SELECT var1 IS NULL;
+
+DROP VARIABLE var1;
--
2.48.1
[text/x-patch] v20250220-0011-implementation-of-temporary-session-variables.patch (40.7K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/13-v20250220-0011-implementation-of-temporary-session-variables.patch)
download | inline diff:
From a956cf88fa0be957cd87aa8168e5bcb198fff993 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:00:28 +0100
Subject: [PATCH 11/21] implementation of temporary session variables
The temporary variables are created inside temp schema and they are dropped by dropping
this schema. For consistency with temp tables, the CREATE TEMP VARIABLE command supports
ON COMMIT DROP clause. The temporary variables with this clause are collected in xact_drop_items
list. This list should be carefully maintained and can contain only valid entries (not
yet dropped). From this reasons now the subcommit and subaborting have to be handled.
---
doc/src/sgml/catalogs.sgml | 10 +
doc/src/sgml/ddl.sgml | 6 +-
doc/src/sgml/ref/create_variable.sgml | 15 +-
src/backend/access/transam/xact.c | 9 +
src/backend/catalog/pg_variable.c | 27 ++-
src/backend/commands/session_variable.c | 218 +++++++++++++++++-
src/backend/commands/view.c | 2 +-
src/backend/parser/analyze.c | 4 +-
src/backend/parser/gram.y | 30 ++-
src/backend/parser/parse_relation.c | 22 +-
src/bin/psql/describe.c | 10 +-
src/bin/psql/tab-complete.in.c | 5 +-
src/include/catalog/pg_variable.h | 9 +
src/include/commands/session_variable.h | 6 +-
src/include/nodes/parsenodes.h | 1 +
src/include/nodes/primnodes.h | 4 +-
src/include/parser/parse_relation.h | 2 +-
.../isolation/expected/session-variable.out | 3 +-
.../isolation/specs/session-variable.spec | 3 +-
src/test/regress/expected/psql.out | 36 +--
.../regress/expected/session_variables.out | 120 ++++++++++
src/test/regress/sql/session_variables.sql | 66 ++++++
src/tools/pgindent/typedefs.list | 1 +
23 files changed, 544 insertions(+), 65 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 4f502274bfa..09b635c234a 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9865,6 +9865,16 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varxactendaction</structfield> <type>char</type>
+ </para>
+ <para>
+ Action performed at end of transaction:
+ <literal>n</literal> = no action, <literal>d</literal> = drop the variable.
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>varcollation</structfield> <type>oid</type>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4e8e7c6a42a..3e2cb3c46eb 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5412,9 +5412,9 @@ SELECT current_user_id;
<command>LET</command> command. Session variables are not transactional:
any changes made to the value of a session variable in a transaction won't
be undone if the transaction is rolled back (just like variables in
- procedural languages). Session variables themselves are persistent, but
- their values are neither persistent nor shared (like the content of
- temporary tables).
+ procedural languages). Session variables themselves can be persistent
+ or temporary, but their values are neither persistent nor shared (like the
+ content of temporary tables).
</para>
<para>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index cd9ff63975a..a88e0175bea 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -26,7 +26,8 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+ [ ON COMMIT DROP ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -104,6 +105,18 @@ CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceab
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-on-commit-drop">
+ <term><literal>ON COMMIT DROP</literal></term>
+ <listitem>
+ <para>
+ The <literal>ON COMMIT DROP</literal> clause specifies the behaviour of a
+ temporary session variable at transaction commit. With this clause, the
+ session variable is dropped at commit time. The clause is only allowed
+ for temporary variables.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</refsect1>
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 1b4f21a88d3..4e6216306da 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -36,6 +36,7 @@
#include "catalog/pg_enum.h"
#include "catalog/storage.h"
#include "commands/async.h"
+#include "commands/session_variable.h"
#include "commands/tablecmds.h"
#include "commands/trigger.h"
#include "common/pg_prng.h"
@@ -2316,6 +2317,9 @@ CommitTransaction(void)
*/
smgrDoPendingSyncs(true, is_parallel_worker);
+ /* remove values of dropped session variables from memory */
+ AtPreEOXact_SessionVariables(true);
+
/* close large objects before lower-level cleanup */
AtEOXact_LargeObject(true);
@@ -2912,6 +2916,7 @@ AbortTransaction(void)
AtAbort_Portals();
smgrDoPendingSyncs(false, is_parallel_worker);
AtEOXact_LargeObject(false);
+ AtPreEOXact_SessionVariables(false);
AtAbort_Notify();
AtEOXact_RelationMap(false, is_parallel_worker);
AtAbort_Twophase();
@@ -5177,6 +5182,8 @@ CommitSubTransaction(void)
AtEOSubXact_SPI(true, s->subTransactionId);
AtEOSubXact_on_commit_actions(true, s->subTransactionId,
s->parent->subTransactionId);
+ AtEOSubXact_SessionVariables(true, s->subTransactionId,
+ s->parent->subTransactionId);
AtEOSubXact_Namespace(true, s->subTransactionId,
s->parent->subTransactionId);
AtEOSubXact_Files(true, s->subTransactionId,
@@ -5342,6 +5349,8 @@ AbortSubTransaction(void)
AtEOSubXact_SPI(false, s->subTransactionId);
AtEOSubXact_on_commit_actions(false, s->subTransactionId,
s->parent->subTransactionId);
+ AtEOSubXact_SessionVariables(false, s->subTransactionId,
+ s->parent->subTransactionId);
AtEOSubXact_Namespace(false, s->subTransactionId,
s->parent->subTransactionId);
AtEOSubXact_Files(false, s->subTransactionId,
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index d672d2a9cb3..00c90ea6fd8 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -36,7 +36,8 @@ static ObjectAddress create_variable(const char *varName,
int32 varTypmod,
Oid varOwner,
Oid varCollation,
- bool if_not_exists);
+ bool if_not_exists,
+ VariableXactEndAction varXactEndAction);
/*
@@ -49,7 +50,8 @@ create_variable(const char *varName,
int32 varTypmod,
Oid varOwner,
Oid varCollation,
- bool if_not_exists)
+ bool if_not_exists,
+ VariableXactEndAction varXactEndAction)
{
Acl *varacl;
NameData varname;
@@ -110,6 +112,7 @@ create_variable(const char *varName,
values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+ values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
varNamespace);
@@ -183,6 +186,13 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
Oid typcollation;
ObjectAddress variable;
+ /* check consistency of arguments */
+ if (stmt->XactEndAction == VARIABLE_XACTEND_DROP
+ && stmt->variable->relpersistence != RELPERSISTENCE_TEMP)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+ errmsg("ON COMMIT DROP can only be used on temporary variables")));
+
namespaceid =
RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL);
@@ -222,11 +232,17 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
typmod,
varowner,
collation,
- stmt->if_not_exists);
+ stmt->if_not_exists,
+ stmt->XactEndAction);
elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
stmt->variable->relname, variable.objectId);
+ /* we want SessionVariableCreatePostprocess to see the catalog changes. */
+ CommandCounterIncrement();
+
+ SessionVariableCreatePostprocess(variable.objectId, stmt->XactEndAction);
+
return variable;
}
@@ -239,6 +255,7 @@ DropVariableById(Oid varid)
{
Relation rel;
HeapTuple tup;
+ char XactEndAction;
rel = table_open(VariableRelationId, RowExclusiveLock);
@@ -247,6 +264,8 @@ DropVariableById(Oid varid)
if (!HeapTupleIsValid(tup))
elog(ERROR, "cache lookup failed for variable %u", varid);
+ XactEndAction = ((Form_pg_variable) GETSTRUCT(tup))->varxactendaction;
+
CatalogTupleDelete(rel, &tup->t_self);
ReleaseSysCache(tup);
@@ -254,5 +273,5 @@ DropVariableById(Oid varid)
table_close(rel, RowExclusiveLock);
/* do the necessary cleanup in local memory, if needed */
- SessionVariableDropPostprocess(varid);
+ SessionVariableDropPostprocess(varid, XactEndAction);
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 1596d94fb03..dc51a778bf5 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -16,6 +16,8 @@
#include "access/xact.h"
#include "catalog/pg_variable.h"
+#include "catalog/dependency.h"
+#include "catalog/namespace.h"
#include "commands/session_variable.h"
#include "executor/svariableReceiver.h"
#include "funcapi.h"
@@ -31,6 +33,19 @@
#include "utils/snapmgr.h"
#include "utils/syscache.h"
+typedef struct SVariableXActDropItem
+{
+ Oid varid; /* varid of session variable */
+
+ /*
+ * creating_subid is the ID of the creating subxact. If the action was
+ * unregistered during the current transaction, deleting_subid is the ID
+ * of the deleting subxact, otherwise InvalidSubTransactionId.
+ */
+ SubTransactionId creating_subid;
+ SubTransactionId deleting_subid;
+} SVariableXActDropItem;
+
/*
* The values of session variables are stored in the backend's private memory
* in the dedicated memory context SVariableMemoryContext in binary format.
@@ -96,13 +111,21 @@ static MemoryContext SVariableMemoryContext = NULL;
static bool needs_validation = false;
/*
- * The content of dropped session variables is not removed immediately. We do
- * that in the next transaction that reads or writes a session variable.
- * "validated_lxid" stores the transaction that performed said validation, so
- * that we can avoid repeating the effort.
+ * The content of dropped session variables is not removed immediately. If
+ * possible, we do that at the end of the transaction. But we cannot do that
+ * if the transaction aborted, because we lost access to the system catalog.
+ * In that case, we clean up in the next transaction that reads or writes a
+ * session variable. "validated_lxid" stores the transaction that performed
+ * said validation, so that we can avoid repeating the effort.
*/
static LocalTransactionId validated_lxid = InvalidLocalTransactionId;
+/* list holds fields of SVariableXActDropItem type */
+static List *xact_drop_items = NIL;
+
+static void register_session_variable_xact_drop(Oid varid);
+static void unregister_session_variable_xact_drop(Oid varid);
+
/*
* Callback function for session variable invalidation.
*/
@@ -139,16 +162,45 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
}
}
+/*
+ * Do the necessary work to setup local memory management of a new
+ * variable.
+ *
+ * Caller should already have created the necessary entry in catalog
+ * and made them visible.
+ */
+void
+SessionVariableCreatePostprocess(Oid varid, char XactEndAction)
+{
+ /*
+ * For temporary variables, we need to create a new end of xact action to
+ * ensure deletion from catalog.
+ */
+ if (XactEndAction == VARIABLE_XACTEND_DROP)
+ {
+ Assert(isTempNamespace(get_session_variable_namespace(varid)));
+
+ register_session_variable_xact_drop(varid);
+ }
+}
+
/*
* Handle the local memory cleanup for a DROP VARIABLE command.
*
* Caller should take care of removing the pg_variable entry first.
*/
void
-SessionVariableDropPostprocess(Oid varid)
+SessionVariableDropPostprocess(Oid varid, char XactEndAction)
{
Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid));
+ if (XactEndAction == VARIABLE_XACTEND_DROP)
+ {
+ Assert(isTempNamespace(get_session_variable_namespace(varid)));
+
+ unregister_session_variable_xact_drop(varid);
+ }
+
if (sessionvars)
{
bool found;
@@ -170,6 +222,57 @@ SessionVariableDropPostprocess(Oid varid)
}
}
+/*
+ * Registration of actions to be executed on session variables at transaction
+ * end time. We want to drop temporary session variables with clause ON COMMIT
+ * DROP.
+ */
+
+/*
+ * Register a session variable xact action.
+ */
+static void
+register_session_variable_xact_drop(Oid varid)
+{
+ SVariableXActDropItem *xact_ai;
+ MemoryContext oldcxt;
+
+ oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
+
+ xact_ai = (SVariableXActDropItem *)
+ palloc(sizeof(SVariableXActDropItem));
+
+ xact_ai->varid = varid;
+
+ xact_ai->creating_subid = GetCurrentSubTransactionId();
+ xact_ai->deleting_subid = InvalidSubTransactionId;
+
+ xact_drop_items = lcons(xact_ai, xact_drop_items);
+
+ MemoryContextSwitchTo(oldcxt);
+}
+
+/*
+ * Unregister an id of a given session variable from drop list. In this
+ * moment, the action is just marked as deleted by setting deleting_subid. The
+ * calling even might be rollbacked, in which case we should not lose this
+ * action.
+ */
+static void
+unregister_session_variable_xact_drop(Oid varid)
+{
+ ListCell *l;
+
+ foreach(l, xact_drop_items)
+ {
+ SVariableXActDropItem *xact_ai =
+ (SVariableXActDropItem *) lfirst(l);
+
+ if (xact_ai->varid == varid)
+ xact_ai->deleting_subid = GetCurrentSubTransactionId();
+ }
+}
+
/*
* Release stored value, free memory
*/
@@ -222,9 +325,11 @@ is_session_variable_valid(SVariable svar)
/*
* Check all potentially invalid session variable data in local memory and free
* the memory for all invalid ones. This function is called before any read or
- * write of a session variable. Freeing of a variable's memory is postponed if
- * the variable has been dropped by the current transaction, since that
- * operation could still be rolled back.
+ * write of a session variable or when the transaction ends. At the end of a
+ * transaction (atEOX is true) we can discard all invalid variables. Inside a
+ * transaction (atEOX is false) we postpone freeing a variable's memory if the
+ * variable has been dropped by the current transaction, since that operation
+ * could still be rolled back.
*
* It is possible that we receive a cache invalidation message while
* remove_invalid_session_variables() is executing, so we cannot guarantee that
@@ -232,7 +337,7 @@ is_session_variable_valid(SVariable svar)
* done. However, we can guarantee that all entries get checked once.
*/
static void
-remove_invalid_session_variables(void)
+remove_invalid_session_variables(bool atEOX)
{
HASH_SEQ_STATUS status;
SVariable svar;
@@ -259,7 +364,7 @@ remove_invalid_session_variables(void)
{
if (!svar->is_valid)
{
- if (svar->drop_lxid == MyProc->vxid.lxid)
+ if (!atEOX && svar->drop_lxid == MyProc->vxid.lxid)
{
/* try again in the next transaction */
needs_validation = true;
@@ -280,6 +385,95 @@ remove_invalid_session_variables(void)
}
}
+/*
+ * Perform ON COMMIT DROP for temporary session variables,
+ * and remove all dropped variables from memory.
+ */
+void
+AtPreEOXact_SessionVariables(bool isCommit)
+{
+ if (isCommit)
+ {
+ if (xact_drop_items)
+ {
+ ListCell *l;
+
+ foreach(l, xact_drop_items)
+ {
+ SVariableXActDropItem *xact_ai =
+ (SVariableXActDropItem *) lfirst(l);
+
+ /* iterate only over entries that are still pending */
+ if (xact_ai->deleting_subid == InvalidSubTransactionId)
+ {
+ ObjectAddress object;
+
+ object.classId = VariableRelationId;
+ object.objectId = xact_ai->varid;
+ object.objectSubId = 0;
+
+ /*
+ * Since this is an automatic drop, rather than one
+ * directly initiated by the user, we pass the
+ * PERFORM_DELETION_INTERNAL flag.
+ */
+ elog(DEBUG1, "session variable (oid:%u) will be deleted (forced by ON COMMIT DROP clause)",
+ xact_ai->varid);
+
+ performDeletion(&object, DROP_CASCADE,
+ PERFORM_DELETION_INTERNAL |
+ PERFORM_DELETION_QUIETLY);
+ }
+ }
+ }
+
+ remove_invalid_session_variables(true);
+ }
+
+ /*
+ * We have to clean xact_drop_items. All related variables are dropped
+ * now, or lost inside aborted transaction.
+ */
+ list_free_deep(xact_drop_items);
+ xact_drop_items = NULL;
+}
+
+/*
+ * Post-subcommit or post-subabort cleanup of xact drop list.
+ *
+ * During subabort, we can immediately remove entries created during this
+ * subtransaction. During subcommit, just transfer entries marked during
+ * this subtransaction as being the parent's responsibility.
+ */
+void
+AtEOSubXact_SessionVariables(bool isCommit,
+ SubTransactionId mySubid,
+ SubTransactionId parentSubid)
+{
+ ListCell *cur_item;
+
+ foreach(cur_item, xact_drop_items)
+ {
+ SVariableXActDropItem *xact_ai =
+ (SVariableXActDropItem *) lfirst(cur_item);
+
+ if (!isCommit && xact_ai->creating_subid == mySubid)
+ {
+ /* cur_item must be removed */
+ xact_drop_items = foreach_delete_current(xact_drop_items, cur_item);
+ pfree(xact_ai);
+ }
+ else
+ {
+ /* cur_item must be preserved */
+ if (xact_ai->creating_subid == mySubid)
+ xact_ai->creating_subid = parentSubid;
+ if (xact_ai->deleting_subid == mySubid)
+ xact_ai->deleting_subid = isCommit ? parentSubid : InvalidSubTransactionId;
+ }
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
@@ -438,7 +632,7 @@ get_session_variable(Oid varid)
validated_lxid != MyProc->vxid.lxid)
{
/* free the memory from dropped session variables */
- remove_invalid_session_variables();
+ remove_invalid_session_variables(false);
/* don't repeat the above step in the same transaction */
validated_lxid = MyProc->vxid.lxid;
@@ -534,7 +728,7 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
validated_lxid != MyProc->vxid.lxid)
{
/* free the memory from dropped session variables */
- remove_invalid_session_variables();
+ remove_invalid_session_variables(false);
/* don't repeat the above step in the same transaction */
validated_lxid = MyProc->vxid.lxid;
diff --git a/src/backend/commands/view.c b/src/backend/commands/view.c
index 6f0301555e0..6bef9a2612a 100644
--- a/src/backend/commands/view.c
+++ b/src/backend/commands/view.c
@@ -484,7 +484,7 @@ DefineView(ViewStmt *stmt, const char *queryString,
*/
view = copyObject(stmt->view); /* don't corrupt original command */
if (view->relpersistence == RELPERSISTENCE_PERMANENT
- && isQueryUsingTempRelation(viewParse))
+ && isQueryUsingTempObject(viewParse))
{
view->relpersistence = RELPERSISTENCE_TEMP;
ereport(NOTICE,
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 725f678e2fa..c0c3abd7a0e 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -3491,10 +3491,10 @@ transformCreateTableAsStmt(ParseState *pstate, CreateTableAsStmt *stmt)
* creation query. It would be hard to refresh data or incrementally
* maintain it if a source disappeared.
*/
- if (isQueryUsingTempRelation(query))
+ if (isQueryUsingTempObject(query))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("materialized views must not use temporary tables or views")));
+ errmsg("materialized views must not use temporary tables, views or session variables")));
/*
* A materialized view would either need to save parameters for use in
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index ed656ba6364..4072c155b56 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -473,6 +473,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <ival> OptTemp
%type <ival> OptNoLog
%type <oncommit> OnCommitOption
+%type <ival> XactEndActionOption
%type <ival> for_locking_strength
%type <node> for_locking_item
@@ -5263,26 +5264,39 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause
+ CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- n->variable = $3;
- n->typeName = $5;
- n->collClause = (CollateClause *) $6;
+ $4->relpersistence = $2;
+ n->variable = $4;
+ n->typeName = $6;
+ n->collClause = (CollateClause *) $7;
+ n->XactEndAction = $8;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause
+ | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- n->variable = $6;
- n->typeName = $8;
- n->collClause = (CollateClause *) $9;
+ $7->relpersistence = $2;
+ n->variable = $7;
+ n->typeName = $9;
+ n->collClause = (CollateClause *) $10;
+ n->XactEndAction = $11;
n->if_not_exists = true;
$$ = (Node *) n;
}
;
+/*
+ * Temporary session variables can be dropped on successful
+ * transaction end like tables.
+ */
+XactEndActionOption: ON COMMIT DROP { $$ = VARIABLE_XACTEND_DROP; }
+ | /*EMPTY*/ { $$ = VARIABLE_XACTEND_NOOP; }
+ ;
+
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index 04ecf64b1fc..bec6947ea2d 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -103,7 +103,7 @@ static void expandTupleDesc(TupleDesc tupdesc, Alias *eref,
static int specialAttNum(const char *attname);
static bool rte_visible_if_lateral(ParseState *pstate, RangeTblEntry *rte);
static bool rte_visible_if_qualified(ParseState *pstate, RangeTblEntry *rte);
-static bool isQueryUsingTempRelation_walker(Node *node, void *context);
+static bool isQueryUsingTempObject_walker(Node *node, void *context);
/*
@@ -3927,13 +3927,13 @@ rte_visible_if_qualified(ParseState *pstate, RangeTblEntry *rte)
* the query is a temporary relation (table, view, or materialized view).
*/
bool
-isQueryUsingTempRelation(Query *query)
+isQueryUsingTempObject(Query *query)
{
- return isQueryUsingTempRelation_walker((Node *) query, NULL);
+ return isQueryUsingTempObject_walker((Node *) query, NULL);
}
static bool
-isQueryUsingTempRelation_walker(Node *node, void *context)
+isQueryUsingTempObject_walker(Node *node, void *context)
{
if (node == NULL)
return false;
@@ -3959,13 +3959,23 @@ isQueryUsingTempRelation_walker(Node *node, void *context)
}
return query_tree_walker(query,
- isQueryUsingTempRelation_walker,
+ isQueryUsingTempObject_walker,
context,
QTW_IGNORE_JOINALIASES);
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ if (isAnyTempNamespace(get_session_variable_namespace(p->paramvarid)))
+ return true;
+ }
+ }
return expression_tree_walker(node,
- isQueryUsingTempRelation_walker,
+ isQueryUsingTempObject_walker,
context);
}
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 783cbb9cd11..50ddcc24140 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5351,12 +5351,16 @@ listVariables(const char *pattern, bool verbose)
" pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n"
" (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
" WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
- " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n",
+ " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
+ " CASE v.varxactendaction\n"
+ " WHEN 'd' THEN 'ON COMMIT DROP'\n"
+ " END as \"%s\"\n",
gettext_noop("Schema"),
gettext_noop("Name"),
gettext_noop("Type"),
gettext_noop("Collation"),
- gettext_noop("Owner"));
+ gettext_noop("Owner"),
+ gettext_noop("Transactional end action"));
if (verbose)
{
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 054c3bba6b9..88f25acec0f 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -3637,7 +3637,7 @@ match_previous_words(int pattern_id,
/* CREATE TABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete "CREATE TEMP/TEMPORARY" with the possible temp objects */
else if (TailMatches("CREATE", "TEMP|TEMPORARY"))
- COMPLETE_WITH("SEQUENCE", "TABLE", "VIEW");
+ COMPLETE_WITH("SEQUENCE", "TABLE", "VARIABLE", "VIEW");
/* Complete "CREATE UNLOGGED" with TABLE or SEQUENCE */
else if (TailMatches("CREATE", "UNLOGGED"))
COMPLETE_WITH("TABLE", "SEQUENCE");
@@ -3988,7 +3988,8 @@ match_previous_words(int pattern_id,
}
/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE VARIABLE <name> with AS */
- else if (TailMatches("CREATE", "VARIABLE", MatchAny))
+ else if (TailMatches("CREATE", "VARIABLE", MatchAny) ||
+ TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny))
COMPLETE_WITH("AS");
else if (TailMatches("VARIABLE", MatchAny, "AS"))
/* Complete CREATE VARIABLE <name> with AS types */
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 5b45be5afaf..0fc672bc2ba 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -56,6 +56,9 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* typmod for variable's type */
int32 vartypmod BKI_DEFAULT(-1);
+ /* action on transaction end */
+ char varxactendaction BKI_DEFAULT(n);
+
/* variable collation */
Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation);
@@ -68,6 +71,12 @@ CATALOG(pg_variable,9222,VariableRelationId)
#endif
} FormData_pg_variable;
+typedef enum VariableXactEndAction
+{
+ VARIABLE_XACTEND_NOOP = 'n', /* NOOP */
+ VARIABLE_XACTEND_DROP = 'd', /* ON COMMIT DROP */
+} VariableXactEndAction;
+
/* ----------------
* Form_pg_variable corresponds to a pointer to a tuple with
* the format of the pg_variable relation.
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index d3cc79b5608..4492bee6d69 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -21,7 +21,11 @@
#include "tcop/cmdtag.h"
#include "utils/queryenvironment.h"
-extern void SessionVariableDropPostprocess(Oid varid);
+extern void SessionVariableCreatePostprocess(Oid varid, char XactEndAction);
+extern void SessionVariableDropPostprocess(Oid varid, char XactEndAction);
+extern void AtPreEOXact_SessionVariables(bool isCommit);
+extern void AtEOSubXact_SessionVariables(bool isCommit, SubTransactionId mySubid,
+ SubTransactionId parentSubid);
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 6327dba3b71..2e4d9ab5f47 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3546,6 +3546,7 @@ typedef struct CreateSessionVarStmt
TypeName *typeName; /* the type of variable */
CollateClause *collClause;
bool if_not_exists; /* do nothing if it already exists */
+ char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 98b9285a54b..34d051ec98a 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -52,7 +52,9 @@ typedef struct Alias
List *colnames; /* optional list of column aliases */
} Alias;
-/* What to do at commit time for temporary relations */
+/*
+ * What to do at commit time for temporary relations or session variables.
+ */
typedef enum OnCommitAction
{
ONCOMMIT_NOOP, /* No ON COMMIT clause (do nothing) */
diff --git a/src/include/parser/parse_relation.h b/src/include/parser/parse_relation.h
index 3ece5cd4eef..3529bfa5b30 100644
--- a/src/include/parser/parse_relation.h
+++ b/src/include/parser/parse_relation.h
@@ -127,6 +127,6 @@ extern int attnameAttNum(Relation rd, const char *attname, bool sysColOK);
extern const NameData *attnumAttName(Relation rd, int attid);
extern Oid attnumTypeId(Relation rd, int attid);
extern Oid attnumCollationId(Relation rd, int attid);
-extern bool isQueryUsingTempRelation(Query *query);
+extern bool isQueryUsingTempObject(Query *query);
#endif /* PARSE_RELATION_H */
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
index 0a5579dc7ce..a609797dc5d 100644
--- a/src/test/isolation/expected/session-variable.out
+++ b/src/test/isolation/expected/session-variable.out
@@ -86,10 +86,11 @@ myvar
step sr1: ROLLBACK;
-starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+starting permutation: create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
step create3: CREATE VARIABLE myvar3 AS text;
step let3: LET myvar3 = 'test';
step s3: BEGIN;
+step o_c_d: CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP;
step create4: CREATE VARIABLE myvar4 AS text;
step let4: LET myvar4 = 'test';
step drop4: DROP VARIABLE myvar4;
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
index c864fee4006..45e65d4085d 100644
--- a/src/test/isolation/specs/session-variable.spec
+++ b/src/test/isolation/specs/session-variable.spec
@@ -24,6 +24,7 @@ step create { CREATE VARIABLE myvar AS text; }
session s3
step s3 { BEGIN; }
step let3 { LET myvar3 = 'test'; }
+step o_c_d { CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP; }
step create4 { CREATE VARIABLE myvar4 AS text; }
step let4 { LET myvar4 = 'test'; }
step drop4 { DROP VARIABLE myvar4; }
@@ -47,4 +48,4 @@ permutation let val dbg drop create dbg val
# calling the dbg step after the concurrent drop
permutation let val s1 dbg drop create dbg val sr1
# test for DISCARD ALL when all internal queues have actions registered
-permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+permutation create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 0c48fdfaf61..3ddbcc7cc2a 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6020,20 +6020,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Access privileges | Description
---------+------+-------------------+-----------+------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Access privileges | Description
---------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6501,9 +6501,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner
---------+------+------+-----------+-------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action
+--------+------+------+-----------+-------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6676,9 +6676,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner
---------+------+------+-----------+-------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action
+--------+------+------+-----------+-------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6815,9 +6815,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner
---------+------+------+-----------+-------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action
+--------+------+------+-----------+-------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 6049f689f24..14e093eb8a7 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2145,3 +2145,123 @@ SELECT var1;
DEALLOCATE p1;
DROP VARIABLE var1;
+-- temporary variables
+CREATE TEMP VARIABLE var1 AS int;
+-- this view should be temporary
+CREATE VIEW var_test_view AS SELECT var1;
+NOTICE: view "var_test_view" will be a temporary view
+DROP VARIABLE var1 CASCADE;
+NOTICE: drop cascades to view var_test_view
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+ROLLBACK;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ ROLLBACK TO s1;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 18b59fc9cad..e6ccc37153d 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1312,6 +1312,7 @@ BEGIN;
DROP VARIABLE var1;
SELECT var2;
ROLLBACK;
+
-- should be ok
SELECT var1;
@@ -1479,3 +1480,68 @@ SELECT var1;
DEALLOCATE p1;
DROP VARIABLE var1;
+
+-- temporary variables
+CREATE TEMP VARIABLE var1 AS int;
+-- this view should be temporary
+CREATE VIEW var_test_view AS SELECT var1;
+
+DROP VARIABLE var1 CASCADE;
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+ROLLBACK;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+ROLLBACK;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ ROLLBACK TO s1;
+ SELECT var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index c42304dd4bb..794cd7b7619 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2831,6 +2831,7 @@ SupportRequestWFuncMonotonic
SVariable
SVariableData
SVariableState
+SVariableXActDropItem
Syn
SyncOps
SyncRepConfigData
--
2.48.1
[text/x-patch] v20250220-0010-PREPARE-LET-support.patch (7.4K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/14-v20250220-0010-PREPARE-LET-support.patch)
download | inline diff:
From 1e5111df690bcb7cb50e7ba79162d6cbc0c8d8b8 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 09:44:58 +0100
Subject: [PATCH 10/21] PREPARE LET support
In current code base it requires just small changes in parser. It is nice
to have to have possibility to use prepared LET statements mainly due reduction
of security risks (SQL injection), and implementation is almost cheap.
Explicit preparing is not necessity for support of LET statements in PL, because
PL uses SPI for query execution, but it is nice to have this possibility (completenees, ...)
---
doc/src/sgml/ref/prepare.sgml | 4 +-
src/backend/parser/gram.y | 3 +-
src/backend/parser/parse_cte.c | 7 ++
src/bin/psql/tab-complete.in.c | 4 +-
.../regress/expected/session_variables.out | 81 ++++++++++++++++++-
src/test/regress/sql/session_variables.sql | 57 +++++++++++++
6 files changed, 149 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/ref/prepare.sgml b/doc/src/sgml/ref/prepare.sgml
index 8ee9439f611..45d72b1d52b 100644
--- a/doc/src/sgml/ref/prepare.sgml
+++ b/doc/src/sgml/ref/prepare.sgml
@@ -116,8 +116,8 @@ PREPARE <replaceable class="parameter">name</replaceable> [ ( <replaceable class
<listitem>
<para>
Any <command>SELECT</command>, <command>INSERT</command>, <command>UPDATE</command>,
- <command>DELETE</command>, <command>MERGE</command>, or <command>VALUES</command>
- statement.
+ <command>DELETE</command>, <command>MERGE</command>, <command>VALUES</command>,
+ or <command>LET</command> statement.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 73e2ecb662c..ed656ba6364 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -12198,7 +12198,8 @@ PreparableStmt:
| InsertStmt
| UpdateStmt
| DeleteStmt
- | MergeStmt /* by default all are $$=$1 */
+ | MergeStmt
+ | LetStmt /* by default all are $$=$1 */
;
/*****************************************************************************
diff --git a/src/backend/parser/parse_cte.c b/src/backend/parser/parse_cte.c
index 79673621c9b..c62761e4eae 100644
--- a/src/backend/parser/parse_cte.c
+++ b/src/backend/parser/parse_cte.c
@@ -126,6 +126,13 @@ transformWithClause(ParseState *pstate, WithClause *withClause)
CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
ListCell *rest;
+ /* LET is allowed by parser, but not supported. Reject for now */
+ if (IsA(cte->ctequery, LetStmt))
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("LET not supported in WITH query"),
+ parser_errposition(pstate, cte->location));
+
for_each_cell(rest, withClause->ctes, lnext(withClause->ctes, lc))
{
CommonTableExpr *cte2 = (CommonTableExpr *) lfirst(rest);
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 8137eb73223..054c3bba6b9 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4689,9 +4689,9 @@ match_previous_words(int pattern_id,
else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES"))
COMPLETE_WITH("(");
-/* LET */
+/* LET, EXPLAIN LET, PREPARE LET */
/* If prev. word is LET suggest a list of variables */
- else if (Matches("LET"))
+ else if (TailMatches("LET"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
/* Complete LET <variable> with "=" */
else if (TailMatches("LET", MatchAny))
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 0cae7454545..6049f689f24 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -940,9 +940,9 @@ DROP VARIABLE var1, var2;
-- the LET statement should be disallowed in CTE
CREATE VARIABLE var1 AS int;
WITH x AS (LET var1 = 100) SELECT * FROM x;
-ERROR: syntax error at or near "LET"
+ERROR: LET not supported in WITH query
LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x;
- ^
+ ^
-- should be ok
LET var1 = generate_series(1, 1);
-- should fail
@@ -2066,5 +2066,82 @@ SELECT var1;
10
(1 row)
+SET plan_cache_mode TO force_generic_plan;
+PREPARE p1 AS LET var1 = (SELECT count(*) FROM var_tab_test_table);
+LET var1 = NULL;
+EXPLAIN (COSTS OFF) EXECUTE p1;
+ QUERY PLAN
+----------------------------------------------
+ SET SESSION VARIABLE
+ Result
+ InitPlan 1
+ -> Aggregate
+ -> Seq Scan on var_tab_test_table
+(5 rows)
+
+-- should be NULL
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) EXECUTE p1;
+ QUERY PLAN
+-----------------------------------------------------------------------
+ SET SESSION VARIABLE
+ Result (actual rows=1 loops=1)
+ InitPlan 1
+ -> Aggregate (actual rows=1 loops=1)
+ -> Seq Scan on var_tab_test_table (actual rows=10 loops=1)
+(5 rows)
+
+-- should be 10
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SET plan_cache_mode TO DEFAULT;
+DEALLOCATE p1;
DROP VARIABLE var1;
DROP TABLE var_tab_test_table;
+CREATE VARIABLE var1 numeric;
+SET plan_cache_mode TO force_generic_plan;
+PREPARE p1(numeric) AS LET var1 = $1;
+PREPARE p2 AS SELECT var1;
+EXECUTE p1(pi() + 100);
+EXECUTE p2;
+ var1
+-----------------
+ 103.14159265359
+(1 row)
+
+-- prepared plan cache invalidation test
+DROP VARIABLE var1;
+CREATE VARIABLE var1 numeric;
+-- should be NULL
+EXECUTE p2;
+ var1
+------
+
+(1 row)
+
+DEALLOCATE p1;
+DEALLOCATE p2;
+DROP VARIABLE var1;
+SET plan_cache_mode TO force_generic_plan;
+CREATE VARIABLE var1 numeric[];
+PREPARE p1(int, numeric) AS LET var1[$1] = $2;
+LET var1 = '{}'::numeric[];
+EXECUTE p1(1, 10.2);
+EXECUTE p1(2, 10.3);
+SELECT var1;
+ var1
+-------------
+ {10.2,10.3}
+(1 row)
+
+DEALLOCATE p1;
+DROP VARIABLE var1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 3d0eb8c7ad9..18b59fc9cad 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1420,5 +1420,62 @@ EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) LET var1 = (S
-- should be 10
SELECT var1;
+SET plan_cache_mode TO force_generic_plan;
+
+PREPARE p1 AS LET var1 = (SELECT count(*) FROM var_tab_test_table);
+
+LET var1 = NULL;
+
+EXPLAIN (COSTS OFF) EXECUTE p1;
+
+-- should be NULL
+SELECT var1;
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) EXECUTE p1;
+
+-- should be 10
+SELECT var1;
+
+SET plan_cache_mode TO DEFAULT;
+
+DEALLOCATE p1;
+
DROP VARIABLE var1;
DROP TABLE var_tab_test_table;
+
+CREATE VARIABLE var1 numeric;
+
+SET plan_cache_mode TO force_generic_plan;
+
+PREPARE p1(numeric) AS LET var1 = $1;
+PREPARE p2 AS SELECT var1;
+
+EXECUTE p1(pi() + 100);
+EXECUTE p2;
+
+-- prepared plan cache invalidation test
+DROP VARIABLE var1;
+CREATE VARIABLE var1 numeric;
+
+-- should be NULL
+EXECUTE p2;
+
+DEALLOCATE p1;
+DEALLOCATE p2;
+
+DROP VARIABLE var1;
+
+SET plan_cache_mode TO force_generic_plan;
+
+CREATE VARIABLE var1 numeric[];
+
+PREPARE p1(int, numeric) AS LET var1[$1] = $2;
+
+LET var1 = '{}'::numeric[];
+EXECUTE p1(1, 10.2);
+EXECUTE p1(2, 10.3);
+
+SELECT var1;
+
+DEALLOCATE p1;
+DROP VARIABLE var1;
--
2.48.1
[text/x-patch] v20250220-0009-EXPLAIN-LET-support.patch (8.2K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/15-v20250220-0009-EXPLAIN-LET-support.patch)
download | inline diff:
From c67f7af8bf6df154ce297dc3f0d2d881b683912b Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 21 May 2024 18:28:07 +0200
Subject: [PATCH 09/21] EXPLAIN LET support
Enhancing ExplainOnePlan is necessary to be EXPLAIN ANALYZE LET fully workable.
In this case we want to be result of query or expression written to target variable.
---
doc/src/sgml/ref/explain.sgml | 3 +-
src/backend/commands/explain.c | 28 +++++++++++--
src/backend/commands/prepare.c | 5 ++-
src/backend/parser/gram.y | 3 +-
src/include/commands/explain.h | 2 +-
.../regress/expected/session_variables.out | 40 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 21 ++++++++++
7 files changed, 94 insertions(+), 8 deletions(-)
diff --git a/doc/src/sgml/ref/explain.sgml b/doc/src/sgml/ref/explain.sgml
index 652ece7213a..e88551373f8 100644
--- a/doc/src/sgml/ref/explain.sgml
+++ b/doc/src/sgml/ref/explain.sgml
@@ -98,7 +98,8 @@ EXPLAIN [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] <rep
<command>INSERT</command>, <command>UPDATE</command>,
<command>DELETE</command>, <command>MERGE</command>,
<command>CREATE TABLE AS</command>,
- or <command>EXECUTE</command> statement
+ <command>EXECUTE</command>,
+ or <command>LET</command> statement
without letting the command affect your data, use this approach:
<programlisting>
BEGIN;
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index c368261eeef..7e9f4bb79f9 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -18,6 +18,7 @@
#include "commands/createas.h"
#include "commands/defrem.h"
#include "commands/prepare.h"
+#include "executor/svariableReceiver.h"
#include "foreign/fdwapi.h"
#include "jit/jit.h"
#include "libpq/pqformat.h"
@@ -519,8 +520,8 @@ standard_ExplainOneQuery(Query *query, int cursorOptions,
}
/* run it (if needed) and produce output */
- ExplainOnePlan(plan, NULL, NULL, -1, into, es, queryString, params,
- queryEnv,
+ ExplainOnePlan(plan, NULL, NULL, -1, into, query->resultVariable,
+ es, queryString, params, queryEnv,
&planduration, (es->buffers ? &bufusage : NULL),
es->memory ? &mem_counters : NULL);
}
@@ -619,6 +620,25 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
else
ExplainDummyGroup("Notify", NULL, es);
}
+ else if (IsA(utilityStmt, LetStmt))
+ {
+ LetStmt *letstmt = (LetStmt *) utilityStmt;
+ List *rewritten;
+ Query *query;
+
+ if (es->format == EXPLAIN_FORMAT_TEXT)
+ appendStringInfoString(es->str, "SET SESSION VARIABLE\n");
+ else
+ ExplainDummyGroup("Set Session Variable", NULL, es);
+
+ rewritten = QueryRewrite(castNode(Query, copyObject(letstmt->query)));
+
+ Assert(list_length(rewritten) == 1);
+ query = linitial_node(Query, rewritten);
+ ExplainOneQuery(query,
+ CURSOR_OPT_PARALLEL_OK, NULL, es,
+ pstate, params);
+ }
else
{
if (es->format == EXPLAIN_FORMAT_TEXT)
@@ -644,7 +664,7 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
void
ExplainOnePlan(PlannedStmt *plannedstmt, CachedPlan *cplan,
CachedPlanSource *plansource, int query_index,
- IntoClause *into, ExplainState *es,
+ IntoClause *into, Oid targetvar, ExplainState *es,
const char *queryString, ParamListInfo params,
QueryEnvironment *queryEnv, const instr_time *planduration,
const BufferUsage *bufusage,
@@ -694,6 +714,8 @@ ExplainOnePlan(PlannedStmt *plannedstmt, CachedPlan *cplan,
*/
if (into)
dest = CreateIntoRelDestReceiver(into);
+ else if (OidIsValid(targetvar))
+ dest = CreateVariableDestReceiver(targetvar);
else if (es->serialize != EXPLAIN_SERIALIZE_NONE)
dest = CreateExplainSerializeDestReceiver(es);
else
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 06875a7b411..0f9330005df 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -667,8 +667,9 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
if (pstmt->commandType != CMD_UTILITY)
ExplainOnePlan(pstmt, cplan, entry->plansource, query_index,
- into, es, query_string, paramLI, pstate->p_queryEnv,
- &planduration, (es->buffers ? &bufusage : NULL),
+ into, InvalidOid, es, query_string, paramLI,
+ pstate->p_queryEnv, &planduration,
+ (es->buffers ? &bufusage : NULL),
es->memory ? &mem_counters : NULL);
else
ExplainOneUtility(pstmt->utilityStmt, into, es, pstate, paramLI);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 4fffb28dd4d..73e2ecb662c 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -12167,7 +12167,8 @@ ExplainableStmt:
| CreateAsStmt
| CreateMatViewStmt
| RefreshMatViewStmt
- | ExecuteStmt /* by default all are $$=$1 */
+ | ExecuteStmt
+ | LetStmt /* by default all are $$=$1 */
;
/*****************************************************************************
diff --git a/src/include/commands/explain.h b/src/include/commands/explain.h
index 570e7cad1fa..5df33334539 100644
--- a/src/include/commands/explain.h
+++ b/src/include/commands/explain.h
@@ -105,7 +105,7 @@ extern void ExplainOneUtility(Node *utilityStmt, IntoClause *into,
extern void ExplainOnePlan(PlannedStmt *plannedstmt, CachedPlan *cplan,
CachedPlanSource *plansource, int plan_index,
- IntoClause *into, ExplainState *es,
+ IntoClause *into, Oid targetvar, ExplainState *es,
const char *queryString,
ParamListInfo params, QueryEnvironment *queryEnv,
const instr_time *planduration,
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 9ac08a14e0b..0cae7454545 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2028,3 +2028,43 @@ DROP SCHEMA testvar;
SET session_variables_ambiguity_warning TO DEFAULT;
SET session_variables_use_fence_warning_guard TO DEFAULT;
SET search_path TO DEFAULT;
+CREATE VARIABLE var1 bigint;
+CREATE TABLE var_tab_test_table(a int);
+INSERT INTO var_tab_test_table SELECT * FROM generate_series(1,10);
+VACUUM ANALYZE var_tab_test_table;
+EXPLAIN (COSTS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+ QUERY PLAN
+----------------------------------------------
+ SET SESSION VARIABLE
+ Result
+ InitPlan 1
+ -> Aggregate
+ -> Seq Scan on var_tab_test_table
+(5 rows)
+
+-- should be NULL
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+ QUERY PLAN
+-----------------------------------------------------------------------
+ SET SESSION VARIABLE
+ Result (actual rows=1 loops=1)
+ InitPlan 1
+ -> Aggregate (actual rows=1 loops=1)
+ -> Seq Scan on var_tab_test_table (actual rows=10 loops=1)
+(5 rows)
+
+-- should be 10
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1;
+DROP TABLE var_tab_test_table;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index c5420183d94..3d0eb8c7ad9 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1401,3 +1401,24 @@ DROP SCHEMA testvar;
SET session_variables_ambiguity_warning TO DEFAULT;
SET session_variables_use_fence_warning_guard TO DEFAULT;
SET search_path TO DEFAULT;
+
+CREATE VARIABLE var1 bigint;
+
+CREATE TABLE var_tab_test_table(a int);
+
+INSERT INTO var_tab_test_table SELECT * FROM generate_series(1,10);
+
+VACUUM ANALYZE var_tab_test_table;
+
+EXPLAIN (COSTS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+
+-- should be NULL
+SELECT var1;
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+
+-- should be 10
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP TABLE var_tab_test_table;
--
2.48.1
[text/x-patch] v20250220-0007-GUC-session_variables_ambiguity_warning.patch (15.1K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/16-v20250220-0007-GUC-session_variables_ambiguity_warning.patch)
download | inline diff:
From 0971c4f294dc2b768a84b01788975ed52f406e78 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 21 May 2024 17:55:24 +0200
Subject: [PATCH 07/21] GUC session_variables_ambiguity_warning
Inside an query the session variables can be shadowed. This behaviour is by design,
because this ensuring so new variables doesn't break existing queries. But this
behaviour can be confusing, because shadowing is quiet.
When new GUC session_variables_ambiguity_warning is on, then the warning
is displayed, when some session variable can be used, but it is not used
due shadowing. This feature should to help with investigation of unexpected
behaviour.
Note: PLpgSQL has an option that controls priority of identifier's spaces
(SQL or PLpgSQL). Default behaviour doesn't allows collisions. I believe
this default is the best. I cannot to implement similar very strict
behaviour to session variables, because one unhappy named session variable
can breaks an applications. The problems related to badly named PLpgSQL's
varible is limitted just to only one routine.
---
doc/src/sgml/config.sgml | 60 +++++++++++++++++++
doc/src/sgml/ddl.sgml | 11 ++++
src/backend/parser/parse_expr.c | 49 +++++++++++++--
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/parser/parse_expr.h | 1 +
.../src/expected/plpgsql_session_variable.out | 33 ++++++++++
.../src/sql/plpgsql_session_variable.sql | 29 +++++++++
.../regress/expected/session_variables.out | 26 ++++++++
src/test/regress/sql/session_variables.sql | 26 ++++++++
10 files changed, 241 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 007746a4429..be5d09f7b01 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11022,6 +11022,66 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-ambiguity-warning" xreflabel="session_variables_ambiguity_warning">
+ <term><varname>session_variables_ambiguity_warning</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_ambiguity_warning</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when any identifier in a query could be
+ used as both a column identifier, routine variable or a session
+ variable identifier. The default is <literal>off</literal>.
+ </para>
+ <para>
+ Session variables can be shadowed by column references in a query, this
+ is an expected behavior. Previously working queries shouldn't error out
+ by creating any session variable, so session variables are always shadowed
+ if an identifier is ambiguous. Variables should be referenced using
+ anunambiguous identifier without any possibility for a collision with
+ identifier of other database objects (column names or record fields names).
+ The warning messages emitted when enabling <varname>session_variables_ambiguity_warning</varname>
+ can help finding such identifier collision.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE a int;
+LET a = 100;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+ a
+----
+ 10
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_ambiguity_warning TO on;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a FROM foo;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a
+----
+ 10
+(1 row)
+</screen>
+ </para>
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. For testing or development environments it's recommended to
+ enable it if you use session variables.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 5e671d5be4d..96912aaa436 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5445,6 +5445,17 @@ SELECT name FROM foo;
Alice
</programlisting>
</para>
+
+ <para>
+ When a query contains identifiers or qualified identifiers that could be
+ used as both a session variable identifiers and as column identifier,
+ then the column identifier is preferred every time. Warnings can be
+ emitted when this situation happens by enabling configuration parameter <xref
+ linkend="guc-session-variables-ambiguity-warning"/>. User can explicitly
+ qualify the source object by syntax <literal>table.column</literal> or
+ <literal>schema.variable</literal>. It is strongly recommended to rename
+ shadowed variables or use qualified names always.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 4f208c7efdd..63f1732f69e 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -45,6 +45,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
+bool session_variables_ambiguity_warning = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -960,11 +961,51 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
*
* SELECT foo.a, foo.b, foo.c FROM foo;
*
- * However, that is very confusing, so we disallow it. We don't try to
- * identify a variable if we know that it would be shadowed.
- * -----
+ * However, that is very confusing, so we disallow it.
+ *
+ * When session_variables_ambiguity_warning is requested, then we
+ * need to identify a variable although we know, so this variable
+ * would be shadowed.
*/
- if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ if (node || (relname && crerr == CRERR_NO_COLUMN))
+ {
+ /*
+ * In this path we just try (if it is wanted) detect if session
+ * variable is shadowed.
+ */
+ if (session_variables_ambiguity_warning)
+ {
+ /*
+ * The AccessShareLock is created on related session variable.
+ * The lock will be kept for the whole transaction.
+ */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, true);
+
+ if (OidIsValid(varid))
+ {
+ /* this path will ending by WARNING. Unlock variable first */
+ UnlockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (node)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is shadowed",
+ NameListToString(cref->fields)),
+ errdetail("Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name."),
+ parser_errposition(pstate, cref->location)));
+ else
+ /* session variable is shadowed by RTE */
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s.%s\" is shadowed",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ errdetail("Session variables can be shadowed by tables or table's aliases with the same name."),
+ parser_errposition(pstate, cref->location)));
+ }
+ }
+ }
+ else
{
/* takes an AccessShareLock on the session variable */
varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 03a6dd49154..c11263cc300 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1627,6 +1627,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_ambiguity_warning", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when reference to a session variable is ambiguous."),
+ NULL
+ },
+ &session_variables_ambiguity_warning,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 5362ff80519..9f793008ab7 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -739,6 +739,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_read_only = off
#default_transaction_deferrable = off
#session_replication_role = 'origin'
+#session_variables_ambiguity_warning = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index efbaff8e710..d2209070181 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -17,6 +17,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
+extern PGDLLIMPORT bool session_variables_ambiguity_warning;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index ab779900596..a6523f7afe2 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -354,6 +354,39 @@ $$;
NOTICE: session variable is 100
NOTICE: plpgsql variable is 1000
NOTICE: variable is 1000
+-- againt with session_variables_ambiguity_warning(on)
+SET session_variables_ambiguity_warning TO on;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+WARNING: session variable "plpgsql_sv_var1" is shadowed
+LINE 1: plpgsql_sv_var1
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+QUERY: plpgsql_sv_var1
+NOTICE: variable is 1000
+SET session_variables_ambiguity_warning TO off;
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
CREATE VARIABLE plpgsql_sv_v text;
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
index a3cc264cf38..9b8e90e81fa 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -260,6 +260,35 @@ BEGIN
END;
$$;
+-- againt with session_variables_ambiguity_warning(on)
+
+SET session_variables_ambiguity_warning TO on;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+SET session_variables_ambiguity_warning TO off;
+
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 2783caa8446..7c350ad5ef9 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1524,6 +1524,9 @@ CREATE TABLE vartest_foo(a int, b int);
INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
-- should to fail
SELECT var1.* FROM vartest_foo;
ERROR: missing FROM-clause entry for table "var1"
@@ -1549,6 +1552,7 @@ SELECT count(var1.*) FROM vartest_foo var1;
2
(1 row)
+SET session_variables_ambiguity_warning TO off;
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
NOTICE: drop cascades to 2 other objects
@@ -1943,3 +1947,25 @@ SELECT var1;
(1 row)
DROP VARIABLE var1, var2;
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+CREATE VARIABLE xxtab.avar int;
+CREATE TABLE public.xxtab(avar int);
+INSERT INTO public.xxtab VALUES(1);
+LET xxtab.avar = 20;
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+WARNING: session variable "xxtab.avar" is shadowed
+LINE 1: SELECT xxtab.avar FROM public.xxtab;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ avar
+------
+ 1
+(1 row)
+
+SET session_variables_ambiguity_warning TO off;
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
+NOTICE: drop cascades to session variable xxtab.avar
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index a624ab8b67f..68be415bf26 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1079,6 +1079,10 @@ INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
+
-- should to fail
SELECT var1.* FROM vartest_foo;
@@ -1091,6 +1095,8 @@ SELECT count(var1.*) FROM vartest_foo;
-- should be ok
SELECT count(var1.*) FROM vartest_foo var1;
+SET session_variables_ambiguity_warning TO off;
+
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
@@ -1334,3 +1340,23 @@ BEGIN; DROP VARIABLE var1; ROLLBACK;
SELECT var1;
DROP VARIABLE var1, var2;
+
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+
+CREATE VARIABLE xxtab.avar int;
+
+CREATE TABLE public.xxtab(avar int);
+
+INSERT INTO public.xxtab VALUES(1);
+
+LET xxtab.avar = 20;
+
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+
+SET session_variables_ambiguity_warning TO off;
+
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
--
2.48.1
[text/x-patch] v20250220-0005-memory-cleaning-after-DROP-VARIABLE.patch (20.9K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/17-v20250220-0005-memory-cleaning-after-DROP-VARIABLE.patch)
download | inline diff:
From 7857b49ec1f2dc776d98e98fd0c163a352c464b2 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 09:31:28 +0100
Subject: [PATCH 05/21] memory cleaning after DROP VARIABLE
Accepting a sinval message invalidates entries in the "sessionvars" hash table.
These entries are validated before any read or write operations on session variables.
When the entry cannot be validated, it is removed. Removal will be delayed when
the variable was dropped by the current transaction, which could still be rolled back.
---
src/backend/catalog/pg_variable.c | 7 +-
src/backend/commands/session_variable.c | 153 +++++++++++-
src/include/commands/session_variable.h | 2 +
.../isolation/expected/session-variable.out | 110 +++++++++
src/test/isolation/isolation_schedule | 1 +
.../isolation/specs/session-variable.spec | 50 ++++
.../regress/expected/session_variables.out | 217 ++++++++++++++++++
src/test/regress/sql/session_variables.sql | 120 ++++++++++
8 files changed, 655 insertions(+), 5 deletions(-)
create mode 100644 src/test/isolation/expected/session-variable.out
create mode 100644 src/test/isolation/specs/session-variable.spec
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index bb445e9434b..d672d2a9cb3 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -22,6 +22,7 @@
#include "catalog/pg_collation.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
@@ -230,7 +231,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
}
/*
- * Drop variable by OID
+ * Drop variable by OID, and register the needed session variable
+ * cleanup.
*/
void
DropVariableById(Oid varid)
@@ -250,4 +252,7 @@ DropVariableById(Oid varid)
ReleaseSysCache(tup);
table_close(rel, RowExclusiveLock);
+
+ /* do the necessary cleanup in local memory, if needed */
+ SessionVariableDropPostprocess(varid);
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index e1c86966998..1596d94fb03 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -14,6 +14,7 @@
*/
#include "postgres.h"
+#include "access/xact.h"
#include "catalog/pg_variable.h"
#include "commands/session_variable.h"
#include "executor/svariableReceiver.h"
@@ -67,6 +68,14 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ /*
+ * Top level local transaction id of the last transaction that dropped the
+ * variable, if any. We need this information to avoid freeing memory for
+ * variables dropped by the local backend, in case the operation is rolled
+ * back.
+ */
+ LocalTransactionId drop_lxid;
+
/*
* Stored value and type description can be outdated when we receive a
* sinval message. We then have to check if the stored data are still
@@ -83,6 +92,17 @@ static HTAB *sessionvars = NULL; /* hash table for session variables */
static MemoryContext SVariableMemoryContext = NULL;
+/* becomes true when we receive a sinval message */
+static bool needs_validation = false;
+
+/*
+ * The content of dropped session variables is not removed immediately. We do
+ * that in the next transaction that reads or writes a session variable.
+ * "validated_lxid" stores the transaction that performed said validation, so
+ * that we can avoid repeating the effort.
+ */
+static LocalTransactionId validated_lxid = InvalidLocalTransactionId;
+
/*
* Callback function for session variable invalidation.
*/
@@ -114,6 +134,38 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
if (hashvalue == 0 || svar->hashvalue == hashvalue)
{
svar->is_valid = false;
+ needs_validation = true;
+ }
+ }
+}
+
+/*
+ * Handle the local memory cleanup for a DROP VARIABLE command.
+ *
+ * Caller should take care of removing the pg_variable entry first.
+ */
+void
+SessionVariableDropPostprocess(Oid varid)
+{
+ Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid));
+
+ if (sessionvars)
+ {
+ bool found;
+ SVariable svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_FIND, &found);
+
+ if (found)
+ {
+ /*
+ * Save the current top level local transaction id to make sure we
+ * won't automatically remove the local variable storage in
+ * validate_all_session_variables() when the invalidation message
+ * from DROP VARIABLE arrives. After all, the transaction could
+ * still be rolled back.
+ */
+ svar->is_valid = false;
+ svar->drop_lxid = MyProc->vxid.lxid;
}
}
}
@@ -167,6 +219,67 @@ is_session_variable_valid(SVariable svar)
return result;
}
+/*
+ * Check all potentially invalid session variable data in local memory and free
+ * the memory for all invalid ones. This function is called before any read or
+ * write of a session variable. Freeing of a variable's memory is postponed if
+ * the variable has been dropped by the current transaction, since that
+ * operation could still be rolled back.
+ *
+ * It is possible that we receive a cache invalidation message while
+ * remove_invalid_session_variables() is executing, so we cannot guarantee that
+ * all entries in "sessionvars" will be set to "is_valid" after the function is
+ * done. However, we can guarantee that all entries get checked once.
+ */
+static void
+remove_invalid_session_variables(void)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ /*
+ * The validation requires system catalog access, so the session state
+ * should be "in transaction".
+ */
+ Assert(IsTransactionState());
+
+ if (!needs_validation || !sessionvars)
+ return;
+
+ /*
+ * Reset the flag before we start the validation. It can be set again
+ * by concurrently incoming sinval messages.
+ */
+ needs_validation = false;
+
+ elog(DEBUG1, "effective call of validate_all_session_variables()");
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (!svar->is_valid)
+ {
+ if (svar->drop_lxid == MyProc->vxid.lxid)
+ {
+ /* try again in the next transaction */
+ needs_validation = true;
+ continue;
+ }
+
+ if (!is_session_variable_valid(svar))
+ {
+ Oid varid = svar->varid;
+
+ free_session_variable_value(svar);
+ hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ else
+ svar->is_valid = true;
+ }
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
@@ -196,6 +309,8 @@ setup_session_variable(SVariable svar, Oid varid)
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+ svar->drop_lxid = InvalidTransactionId;
+
svar->isnull = true;
svar->value = (Datum) 0;
@@ -319,22 +434,42 @@ get_session_variable(Oid varid)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
if (found)
{
+ /*
+ * The session variable could have been dropped by a DROP VARIABLE
+ * statement in a subtransaction that was later rolled back, which
+ * means that we may have to work with the data of a variable marked
+ * as invalid.
+ */
if (!svar->is_valid)
{
/*
- * If there was an invalidation message, the variable might still be
- * valid, but we have to check with the system catalog.
+ * We have to check the system catalog to see if the variable is
+ * still valid, even if an invalidation message set it to invalid.
+ *
+ * The variable must be validated before it is accessed. The oid
+ * should be valid, because the related session variable is already
+ * locked, and remove_invalid_session_variables() would remove
+ * variables dropped by other transactions.
*/
if (is_session_variable_valid(svar))
svar->is_valid = true;
else
- /* if the value cannot be validated, we have to discard it */
- free_session_variable_value(svar);
+ elog(ERROR, "unexpected state of session variable %u", varid);
}
}
else
@@ -395,6 +530,16 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index a8ca43c87af..d3cc79b5608 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -21,6 +21,8 @@
#include "tcop/cmdtag.h"
#include "utils/queryenvironment.h"
+extern void SessionVariableDropPostprocess(Oid varid);
+
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
new file mode 100644
index 00000000000..0a5579dc7ce
--- /dev/null
+++ b/src/test/isolation/expected/session-variable.out
@@ -0,0 +1,110 @@
+Parsed test spec with 4 sessions
+
+starting permutation: let val drop val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+
+starting permutation: let val s1 drop val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+step sr1: ROLLBACK;
+
+starting permutation: let val dbg drop create dbg val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name|removed
+------+----+-------
+ | |t
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+
+starting permutation: let val s1 dbg drop create dbg val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+step sr1: ROLLBACK;
+
+starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+step create3: CREATE VARIABLE myvar3 AS text;
+step let3: LET myvar3 = 'test';
+step s3: BEGIN;
+step create4: CREATE VARIABLE myvar4 AS text;
+step let4: LET myvar4 = 'test';
+step drop4: DROP VARIABLE myvar4;
+step drop3: DROP VARIABLE myvar3;
+step inval3: SELECT COUNT(*) >= 0 FROM pg_foreign_table;
+?column?
+--------
+t
+(1 row)
+
+step discard: DISCARD VARIABLES;
+step sc3: COMMIT;
+step state: SELECT varname FROM pg_variable;
+varname
+-------
+myvar
+(1 row)
+
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 143109aa4da..7453685d046 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -115,3 +115,4 @@ test: serializable-parallel-2
test: serializable-parallel-3
test: matview-write-skew
test: lock-nowait
+test: session-variable
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
new file mode 100644
index 00000000000..c864fee4006
--- /dev/null
+++ b/src/test/isolation/specs/session-variable.spec
@@ -0,0 +1,50 @@
+# Test session variables memory cleanup for sinval
+
+setup
+{
+ CREATE VARIABLE myvar AS text;
+}
+
+teardown
+{
+ DROP VARIABLE IF EXISTS myvar;
+}
+
+session s1
+step s1 { BEGIN; }
+step let { LET myvar = 'test'; }
+step val { SELECT myvar; }
+step dbg { SELECT schema, name, removed FROM pg_session_variables(); }
+step sr1 { ROLLBACK; }
+
+session s2
+step drop { DROP VARIABLE myvar; }
+step create { CREATE VARIABLE myvar AS text; }
+
+session s3
+step s3 { BEGIN; }
+step let3 { LET myvar3 = 'test'; }
+step create4 { CREATE VARIABLE myvar4 AS text; }
+step let4 { LET myvar4 = 'test'; }
+step drop4 { DROP VARIABLE myvar4; }
+step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; }
+step discard { DISCARD VARIABLES; }
+step sc3 { COMMIT; }
+step state { SELECT varname FROM pg_variable; }
+
+session s4
+step create3 { CREATE VARIABLE myvar3 AS text; }
+step drop3 { DROP VARIABLE myvar3; }
+
+# Concurrent drop of a known variable should lead to an error
+permutation let val drop val
+# Same, but with an explicit transaction
+permutation let val s1 drop val sr1
+# Concurrent drop/create of a known variable should lead to empty variable
+permutation let val dbg drop create dbg val
+# Concurrent drop/create of a known variable should lead to empty variable
+# We need a transaction to make sure that we won't accept invalidation when
+# calling the dbg step after the concurrent drop
+permutation let val s1 dbg drop create dbg val sr1
+# test for DISCARD ALL when all internal queues have actions registered
+permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 79ac40768f8..2783caa8446 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1726,3 +1726,220 @@ SELECT count(*) FROM pg_session_variables();
0
(1 row)
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+-- should fail
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1, var2;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 2954759aaed..a624ab8b67f 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1214,3 +1214,123 @@ DISCARD VARIABLES;
-- should be zero again
SELECT count(*) FROM pg_session_variables();
+
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+
+-- should fail
+SELECT var1;
+
+ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ROLLBACK;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+DROP VARIABLE var1, var2;
--
2.48.1
[text/x-patch] v20250220-0008-variable-fence-syntax-support-and-variable-fence-usa.patch (19.5K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/18-v20250220-0008-variable-fence-syntax-support-and-variable-fence-usa.patch)
download | inline diff:
From 80679feb848a4c05f127f245fee372123faee776 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 19 Nov 2024 08:14:53 +0100
Subject: [PATCH 08/21] variable fence syntax support and variable fence usage
guard support
this patch introduces a concept of variable fence - syntax for variable
reference `VARIABLE(varname)` that is not in collision with column reference.
When variable fence usage guard warning is active, then usage variable
without variable fence in the case, where there can be column references,
the the warning is raised.
initial implementation of variable fence
---
doc/src/sgml/config.sgml | 65 ++++++++++++++++
doc/src/sgml/ddl.sgml | 15 ++++
src/backend/nodes/nodeFuncs.c | 6 ++
src/backend/parser/gram.y | 28 ++++++-
src/backend/parser/parse_expr.c | 74 ++++++++++++++++++-
src/backend/parser/parse_target.c | 7 ++
src/backend/utils/adt/ruleutils.c | 12 ++-
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/nodes/parsenodes.h | 10 +++
src/include/nodes/primnodes.h | 2 +
src/include/parser/parse_expr.h | 1 +
.../regress/expected/session_variables.out | 59 +++++++++++++++
src/test/regress/sql/session_variables.sql | 41 ++++++++++
14 files changed, 323 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index be5d09f7b01..532af206703 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11082,6 +11082,71 @@ DETAIL: Session variables can be shadowed by columns, routine's variables and r
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-use-fence-warning-guard" xreflabel="session_variables_use_fence_warning_guard">
+ <term><varname>session_variables_use_fence_warning_guard</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_use_fence_warning_guard</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when a session variable identifier is used
+ inside a query without variable fence. The default is <literal>off</literal>.
+ The warning is raised only when variable is used in places, where an
+ collisions with column names is possible.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE b int;
+LET b = 100;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_use_fence_warning_guard TO on;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "b" is not used inside variable fence
+LINE 1: SELECT a, b FROM foo;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SELECT a, VARIABLE(b) FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+ </para>
+
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. Unless another collision resolution technique is used
+ (dedicated schema or using prefixes like <literal>_</literal>),
+ the use of variable fence syntax is strongly recommended, and this
+ warning should be enabled.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 96912aaa436..4e8e7c6a42a 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5456,6 +5456,21 @@ SELECT name FROM foo;
<literal>schema.variable</literal>. It is strongly recommended to rename
shadowed variables or use qualified names always.
</para>
+
+ <para><firstterm>Variable fence</firstterm> is special syntax for session
+ variable identifier. Only name or qualified name can be used inside the
+ variable fence, and this name is used as only session variable identifier.
+<programlisting>
+SELECT VARIABLE(current_user_id);
+</programlisting>
+ </para>
+
+ <para>
+ When there is a risk of possible collisions between variable identifiers
+ and column names, then using variable fence syntax can be recommended.
+ Usage session variable without variable fence can be detected by
+ warning <xref linkend="guc-session-variables-use-fence-warning-guard"/>.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d8fc3d9fa69..575365eefcd 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1673,6 +1673,9 @@ exprLocation(const Node *expr)
case T_ParamRef:
loc = ((const ParamRef *) expr)->location;
break;
+ case T_VariableFence:
+ loc = ((const VariableFence *) expr)->location;
+ break;
case T_A_Const:
loc = ((const A_Const *) expr)->location;
break;
@@ -4715,6 +4718,9 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_VariableFence:
+ /* we assume the fields contain nothing interesting */
+ break;
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 2cb5c57fb61..4fffb28dd4d 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -525,7 +525,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <node> def_arg columnElem where_clause where_or_current_clause
a_expr b_expr c_expr AexprConst indirection_el opt_slice_bound
columnref in_expr having_clause func_table xmltable array_expr
- OptWhereClause operator_def_arg
+ OptWhereClause operator_def_arg variable_fence
%type <list> opt_column_and_period_list
%type <list> rowsfrom_item rowsfrom_list opt_col_def_list
%type <boolean> opt_ordinality opt_without_overlaps
@@ -882,7 +882,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
*/
%nonassoc UNBOUNDED NESTED /* ideally would have same precedence as IDENT */
%nonassoc IDENT PARTITION RANGE ROWS GROUPS PRECEDING FOLLOWING CUBE ROLLUP
- SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH
+ SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH VARIABLE
%left Op OPERATOR /* multi-character ops and user-defined operators */
%left '+' '-'
%left '*' '/' '%'
@@ -15668,6 +15668,19 @@ c_expr: columnref { $$ = $1; }
else
$$ = $2;
}
+ | variable_fence opt_indirection
+ {
+ if ($2)
+ {
+ A_Indirection *n = makeNode(A_Indirection);
+
+ n->arg = (Node *) $1;
+ n->indirection = check_indirection($2, yyscanner);
+ $$ = (Node *) n;
+ }
+ else
+ $$ = $1;
+ }
| case_expr
{ $$ = $1; }
| func_expr
@@ -17054,6 +17067,17 @@ case_arg: a_expr { $$ = $1; }
| /*EMPTY*/ { $$ = NULL; }
;
+variable_fence:
+ VARIABLE '(' any_name ')'
+ {
+ VariableFence *vf = makeNode(VariableFence);
+
+ vf->varname = $3;
+ vf->location = @3;
+ $$ = (Node *) vf;
+ }
+ ;
+
columnref: ColId
{
$$ = makeColumnRef($1, NIL, @1, yyscanner);
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 63f1732f69e..dd03b1f14db 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -46,6 +46,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
bool session_variables_ambiguity_warning = false;
+bool session_variables_use_fence_warning_guard = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -81,6 +82,7 @@ static Node *transformWholeRowRef(ParseState *pstate,
static Node *transformIndirection(ParseState *pstate, A_Indirection *ind);
static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
static Node *transformCollateClause(ParseState *pstate, CollateClause *c);
+static Node *transformVariableFence(ParseState *pstate, VariableFence *vf);
static Node *transformJsonObjectConstructor(ParseState *pstate,
JsonObjectConstructor *ctor);
static Node *transformJsonArrayConstructor(ParseState *pstate,
@@ -112,7 +114,7 @@ static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
static Node *makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location);
+ char *attrname, bool fenced, int location);
/*
@@ -377,6 +379,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
result = transformJsonFuncExpr(pstate, (JsonFuncExpr *) expr);
break;
+ case T_VariableFence:
+ result = transformVariableFence(pstate, (VariableFence *) expr);
+ break;
+
default:
/* should not reach here */
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
@@ -1028,7 +1034,20 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
node = makeParamSessionVariable(pstate,
varid, typid, typmod, collid,
- attrname, cref->location);
+ attrname, false, cref->location);
+
+ /*
+ * The variable is not inside variable's fence, so raise warning
+ * when variable fence guard is active and the query has FROM
+ * clause.
+ */
+ if (session_variables_use_fence_warning_guard && pstate->p_rtable)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is not used inside variable fence",
+ NameListToString(cref->fields)),
+ errdetail("The collision of session variable' names and column names is possible."),
+ parser_errposition(pstate, cref->location)));
}
}
}
@@ -1071,7 +1090,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
static Node *
makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location)
+ char *attrname, bool fenced, int location)
{
Param *param;
@@ -1079,6 +1098,7 @@ makeParamSessionVariable(ParseState *pstate,
param->paramkind = PARAM_VARIABLE;
param->paramvarid = varid;
+ param->paramvarfenced = fenced;
param->paramtype = typid;
param->paramtypmod = typmod;
param->paramcollid = collid;
@@ -1157,6 +1177,54 @@ transformParamRef(ParseState *pstate, ParamRef *pref)
return result;
}
+static Node *
+transformVariableFence(ParseState *pstate, VariableFence *vf)
+{
+ Node *result;
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* VariableFence can be used only in context when variables are supported */
+ if (!expr_kind_allows_session_variables(pstate->p_expr_kind))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable reference is not supported here"),
+ parser_errposition(pstate, vf->location)));
+
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(vf->varname, &attrname, ¬_unique, false);
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ result = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, true, vf->location);
+ }
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ return result;
+}
+
/* Test whether an a_expr is a plain NULL constant or not */
static bool
exprIsNullConstant(Node *arg)
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d5..cf01bff65a9 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -2034,6 +2034,13 @@ FigureColnameInternal(Node *node, char **name)
(int) ((JsonFuncExpr *) node)->op);
}
break;
+ case T_VariableFence:
+ {
+ /* return last field name */
+ *name = strVal(llast(((VariableFence *) node)->varname));
+ return 2;
+ }
+ break;
default:
break;
}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 7417054c38f..106f82b8bb5 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8682,8 +8682,16 @@ get_parameter(Param *param, deparse_context *context)
/* translate paramvarid to session variable name */
if (param->paramkind == PARAM_VARIABLE)
{
- appendStringInfo(context->buf, "%s",
- generate_session_variable_name(param->paramvarid));
+ if (param->paramvarfenced)
+ {
+ appendStringInfo(context->buf, "VARIABLE(%s)",
+ generate_session_variable_name(param->paramvarid));
+ }
+ else
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ }
return;
}
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index c11263cc300..3c6c6441ce1 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1636,6 +1636,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_use_fence_warning_guard", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when variable is not used inside variable fence."),
+ NULL
+ },
+ &session_variables_use_fence_warning_guard,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 9f793008ab7..deea15246d7 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -740,6 +740,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_deferrable = off
#session_replication_role = 'origin'
#session_variables_ambiguity_warning = off
+#session_variables_use_fence_warning_guard = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 04c6126f22b..6327dba3b71 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -321,6 +321,16 @@ typedef struct ParamRef
ParseLoc location; /* token location, or -1 if unknown */
} ParamRef;
+/*
+ * VariableFence - ensure so fields will be interpretted as a variable
+ */
+typedef struct VariableFence
+{
+ NodeTag type;
+ List *varname; /* variable name (String nodes) */
+ ParseLoc location; /* token location, or -1 if unknown */
+} VariableFence;
+
/*
* A_Expr - infix, prefix, and postfix expressions
*/
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 2fa9b1bcd04..98b9285a54b 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -411,6 +411,8 @@ typedef struct Param
* param is used just for execution of UPDATE operation.
*/
bool parambasenode;
+ /* true when variable is used inside an fence */
+ bool paramvarfenced;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index d2209070181..5bde43758d1 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -18,6 +18,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
extern PGDLLIMPORT bool session_variables_ambiguity_warning;
+extern PGDLLIMPORT bool session_variables_use_fence_warning_guard;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7c350ad5ef9..9ac08a14e0b 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1969,3 +1969,62 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
NOTICE: drop cascades to session variable xxtab.avar
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+CREATE SCHEMA testvar;
+SET search_path TO 'testvar';
+CREATE VARIABLE a AS int;
+LET a = 10;
+CREATE TABLE test_table(a int, b int);
+INSERT INTO test_table VALUES(20, 20);
+-- no warning
+SELECT a;
+ a
+----
+ 10
+(1 row)
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a | b
+----+----
+ 20 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a) FROM test_table;
+ a
+----
+ 10
+(1 row)
+
+ALTER TABLE test_table DROP COLUMN a;
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is not used inside variable fence
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+DROP SCHEMA testvar;
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 68be415bf26..c5420183d94 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1360,3 +1360,44 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
+
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+
+CREATE SCHEMA testvar;
+
+SET search_path TO 'testvar';
+
+CREATE VARIABLE a AS int;
+LET a = 10;
+
+CREATE TABLE test_table(a int, b int);
+
+INSERT INTO test_table VALUES(20, 20);
+
+-- no warning
+SELECT a;
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a) FROM test_table;
+
+ALTER TABLE test_table DROP COLUMN a;
+
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+
+DROP SCHEMA testvar;
+
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
--
2.48.1
[text/x-patch] v20250220-0006-plpgsql-tests.patch (16.9K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/19-v20250220-0006-plpgsql-tests.patch)
download | inline diff:
From fbe5f4a5a2c0706f147062775f24e1b63990b84c Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 14:06:06 +0100
Subject: [PATCH 06/21] plpgsql tests
---
src/pl/plpgsql/src/Makefile | 3 +-
.../src/expected/plpgsql_session_variable.out | 382 ++++++++++++++++++
src/pl/plpgsql/src/meson.build | 1 +
.../src/sql/plpgsql_session_variable.sql | 289 +++++++++++++
4 files changed, 674 insertions(+), 1 deletion(-)
create mode 100644 src/pl/plpgsql/src/expected/plpgsql_session_variable.out
create mode 100644 src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile
index 63cb96fae3e..bbcae27d422 100644
--- a/src/pl/plpgsql/src/Makefile
+++ b/src/pl/plpgsql/src/Makefile
@@ -35,7 +35,8 @@ REGRESS_OPTS = --dbname=$(PL_TESTDB)
REGRESS = plpgsql_array plpgsql_cache plpgsql_call plpgsql_control \
plpgsql_copy plpgsql_domain plpgsql_misc \
plpgsql_record plpgsql_simple plpgsql_transaction \
- plpgsql_trap plpgsql_trigger plpgsql_varprops
+ plpgsql_trap plpgsql_trigger plpgsql_varprops \
+ plpgsql_session_variable
# where to find gen_keywordlist.pl and subsidiary files
TOOLSDIR = $(top_srcdir)/src/tools
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
new file mode 100644
index 00000000000..ab779900596
--- /dev/null
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -0,0 +1,382 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+LET plpgsql_sv_var = pi();
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+NOTICE: value of session variable is 3.14159265358979
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+ pi_multiply_2
+------------------
+ 6.28318530717959
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var;
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+END;
+-- execute outside of a transaction
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP FUNCTION test_func();
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+SET ROLE TO regress_var_owner_role;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_reader_role;
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail
+SELECT var_read_func();
+ERROR: permission denied for session variable plpgsql_sv_var1
+CONTEXT: PL/pgSQL expression "plpgsql_sv_var1"
+PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should be ok
+SELECT var_read_func();
+NOTICE: 10
+ var_read_func
+---------------
+
+(1 row)
+
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+DROP VARIABLE plpgsql_sv_var1;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail, but not crash
+SELECT var_read_func();
+ERROR: column "plpgsql_sv_var1" does not exist
+LINE 1: plpgsql_sv_var1
+ ^
+QUERY: plpgsql_sv_var1
+CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+DROP FUNCTION var_read_func;
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+ inc_var_int
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+LET plpgsql_sv_var2 = 0.0;
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+ inc_var_num
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+NOTICE: variable is 1000
+DROP VARIABLE plpgsql_sv_var1;
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+select ffunc();
+ ffunc
+-------
+ abc
+(1 row)
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+DROP VARIABLE plpgsql_sv_v;
diff --git a/src/pl/plpgsql/src/meson.build b/src/pl/plpgsql/src/meson.build
index 33c49ac25d9..1d01d1c2629 100644
--- a/src/pl/plpgsql/src/meson.build
+++ b/src/pl/plpgsql/src/meson.build
@@ -88,6 +88,7 @@ tests += {
'plpgsql_trap',
'plpgsql_trigger',
'plpgsql_varprops',
+ 'plpgsql_session_variable',
],
},
}
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
new file mode 100644
index 00000000000..a3cc264cf38
--- /dev/null
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -0,0 +1,289 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+
+LET plpgsql_sv_var = pi();
+
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+
+DROP VARIABLE plpgsql_sv_var;
+
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+END;
+
+-- execute outside of a transaction
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+SELECT test_func();
+
+DROP FUNCTION test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+SET ROLE TO regress_var_owner_role;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_reader_role;
+
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should be ok
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail, but not crash
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+DROP FUNCTION var_read_func;
+
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+
+LET plpgsql_sv_var2 = 0.0;
+
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+
+select ffunc();
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+
+DROP VARIABLE plpgsql_sv_v;
--
2.48.1
[text/x-patch] v20250220-0004-DISCARD-VARIABLES.patch (9.6K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/20-v20250220-0004-DISCARD-VARIABLES.patch)
download | inline diff:
From ea20acd12c3f6820534bafb00ebd2e3d6fd2a62e Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sun, 28 Jan 2024 20:54:20 +0100
Subject: [PATCH 04/21] DISCARD VARIABLES
Implementation of DISCARD VARIABLES commands by removing hash table with session variables
and resetting related memory context.
---
doc/src/sgml/ref/discard.sgml | 13 +++-
src/backend/commands/discard.c | 6 ++
src/backend/commands/session_variable.c | 28 ++++++++-
src/backend/parser/gram.y | 6 ++
src/backend/tcop/utility.c | 3 +
src/bin/psql/tab-complete.in.c | 2 +-
src/include/commands/session_variable.h | 2 +
src/include/nodes/parsenodes.h | 1 +
src/include/tcop/cmdtaglist.h | 1 +
.../regress/expected/session_variables.out | 63 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 36 +++++++++++
11 files changed, 158 insertions(+), 3 deletions(-)
diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
index bf44c523cac..61b967f9c9b 100644
--- a/doc/src/sgml/ref/discard.sgml
+++ b/doc/src/sgml/ref/discard.sgml
@@ -21,7 +21,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
+DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES }
</synopsis>
</refsynopsisdiv>
@@ -66,6 +66,16 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>VARIABLES</literal></term>
+ <listitem>
+ <para>
+ Resets the value of all session variables. If a variable
+ is later reused, it is re-initialized to <literal>NULL</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><literal>TEMPORARY</literal> or <literal>TEMP</literal></term>
<listitem>
@@ -93,6 +103,7 @@ SELECT pg_advisory_unlock_all();
DISCARD PLANS;
DISCARD TEMP;
DISCARD SEQUENCES;
+DISCARD VARIABLES;
</programlisting></para>
</listitem>
</varlistentry>
diff --git a/src/backend/commands/discard.c b/src/backend/commands/discard.c
index 81339a75a52..5904a6c4917 100644
--- a/src/backend/commands/discard.c
+++ b/src/backend/commands/discard.c
@@ -18,6 +18,7 @@
#include "commands/async.h"
#include "commands/discard.h"
#include "commands/prepare.h"
+#include "commands/session_variable.h"
#include "commands/sequence.h"
#include "utils/guc.h"
#include "utils/portal.h"
@@ -48,6 +49,10 @@ DiscardCommand(DiscardStmt *stmt, bool isTopLevel)
ResetTempTableNamespace();
break;
+ case DISCARD_VARIABLES:
+ ResetSessionVariables();
+ break;
+
default:
elog(ERROR, "unrecognized DISCARD target: %d", stmt->target);
}
@@ -75,4 +80,5 @@ DiscardAll(bool isTopLevel)
ResetPlanCache();
ResetTempTableNamespace();
ResetSequenceCaches();
+ ResetSessionVariables();
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index fa16f47072e..e1c86966998 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -94,7 +94,13 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
- Assert(sessionvars);
+ /*
+ * There is no guarantee of session variables being initialized, even when
+ * receiving an invalidation callback, as DISCARD [ ALL | VARIABLES ]
+ * destroys the hash table entirely.
+ */
+ if (!sessionvars)
+ return;
/*
* If the hashvalue is not specified, we have to recheck all currently
@@ -619,3 +625,23 @@ pg_session_variables(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+
+/*
+ * Fast drop of the complete content of the session variables hash table, and
+ * cleanup of any list that wouldn't be relevant anymore.
+ * This is used by the DISCARD VARIABLES (and DISCARD ALL) command.
+ */
+void
+ResetSessionVariables(void)
+{
+ /* destroy hash table and reset related memory context */
+ if (sessionvars)
+ {
+ hash_destroy(sessionvars);
+ sessionvars = NULL;
+ }
+
+ /* release memory allocated by session variables */
+ if (SVariableMemoryContext != NULL)
+ MemoryContextReset(SVariableMemoryContext);
+}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 04251bba456..2cb5c57fb61 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -2084,7 +2084,13 @@ DiscardStmt:
n->target = DISCARD_SEQUENCES;
$$ = (Node *) n;
}
+ | DISCARD VARIABLES
+ {
+ DiscardStmt *n = makeNode(DiscardStmt);
+ n->target = DISCARD_VARIABLES;
+ $$ = (Node *) n;
+ }
;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 7a508a3644f..6e4d2310f5c 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -2962,6 +2962,9 @@ CreateCommandTag(Node *parsetree)
case DISCARD_SEQUENCES:
tag = CMDTAG_DISCARD_SEQUENCES;
break;
+ case DISCARD_VARIABLES:
+ tag = CMDTAG_DISCARD_VARIABLES;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index de59ebad700..8137eb73223 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4142,7 +4142,7 @@ match_previous_words(int pattern_id,
/* DISCARD */
else if (Matches("DISCARD"))
- COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP");
+ COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP", "VARIABLES");
/* DO */
else if (Matches("DO"))
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index 2391b9ad443..a8ca43c87af 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -27,4 +27,6 @@ extern Datum GetSessionVariable(Oid varid, bool *isNull);
extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
QueryEnvironment *queryEnv, QueryCompletion *qc);
+extern void ResetSessionVariables(void);
+
#endif
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 40f04098104..04c6126f22b 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -4047,6 +4047,7 @@ typedef enum DiscardMode
DISCARD_PLANS,
DISCARD_SEQUENCES,
DISCARD_TEMP,
+ DISCARD_VARIABLES,
} DiscardMode;
typedef struct DiscardStmt
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index 22082c30008..bef0ac25331 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -135,6 +135,7 @@ PG_CMDTAG(CMDTAG_DISCARD_ALL, "DISCARD ALL", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_PLANS, "DISCARD PLANS", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_SEQUENCES, "DISCARD SEQUENCES", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_TEMP, "DISCARD TEMP", false, false, false)
+PG_CMDTAG(CMDTAG_DISCARD_VARIABLES, "DISCARD VARIABLES", false, false, false)
PG_CMDTAG(CMDTAG_DO, "DO", false, false, false)
PG_CMDTAG(CMDTAG_DROP_ACCESS_METHOD, "DROP ACCESS METHOD", true, false, false)
PG_CMDTAG(CMDTAG_DROP_AGGREGATE, "DROP AGGREGATE", true, false, false)
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index f22467186e3..79ac40768f8 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1663,3 +1663,66 @@ DROP VARIABLE :"DBNAME".:"DBNAME".b;
DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+ var1
+-------
+ Hello
+(1 row)
+
+DISCARD ALL;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT var1;
+ var1
+------
+ AHOJ
+(1 row)
+
+DISCARD VARIABLES;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+DROP VARIABLE var1;
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS varchar;
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DISCARD VARIABLES;
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index e72360d5254..2954759aaed 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1178,3 +1178,39 @@ DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+
+DISCARD ALL;
+SELECT var1;
+
+LET var1 = 'AHOJ';
+SELECT var1;
+
+DISCARD VARIABLES;
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+
+SELECT count(*) FROM pg_session_variables();
+
+CREATE VARIABLE var1 AS varchar;
+
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+
+LET var1 = 'AHOJ';
+
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+
+DISCARD VARIABLES;
+
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
--
2.48.1
[text/x-patch] v20250220-0003-function-pg_session_variables-for-cleaning-tests.patch (4.3K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/21-v20250220-0003-function-pg_session_variables-for-cleaning-tests.patch)
download | inline diff:
From 963b2fecc64b3eb4899ac483a9e103a980029c2e Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 20:01:56 +0100
Subject: [PATCH 03/21] function pg_session_variables for cleaning tests
This is a function designed for testing and debugging. It returns the
content of sessionvars as-is, and can therefore display entries about
session variables that were dropped but for which this backend didn't
process the shared invalidations yet.
---
src/backend/commands/session_variable.c | 92 +++++++++++++++++++++++++
src/include/catalog/pg_proc.dat | 8 +++
2 files changed, 100 insertions(+)
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index d2891a1dcb7..fa16f47072e 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -527,3 +527,95 @@ ExecuteLetStmt(ParseState *pstate,
PopActiveSnapshot();
}
+
+/*
+ * pg_session_variables - designed for testing
+ *
+ * This is a function designed for testing and debugging. It returns the
+ * content of session variables as-is, and can therefore display data about
+ * session variables that were dropped, but for which this backend didn't
+ * process the shared invalidations yet.
+ */
+Datum
+pg_session_variables(PG_FUNCTION_ARGS)
+{
+#define NUM_PG_SESSION_VARIABLES_ATTS 8
+
+ InitMaterializedSRF(fcinfo, 0);
+
+ if (sessionvars)
+ {
+ ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ Datum values[NUM_PG_SESSION_VARIABLES_ATTS];
+ bool nulls[NUM_PG_SESSION_VARIABLES_ATTS];
+ HeapTuple tp;
+ bool var_is_valid = false;
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, 0, sizeof(nulls));
+
+ values[0] = ObjectIdGetDatum(svar->varid);
+ values[3] = ObjectIdGetDatum(svar->typid);
+
+ /*
+ * It is possible that the variable has been dropped from the
+ * catalog, but not yet purged from the hash table.
+ */
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ Form_pg_variable varform = (Form_pg_variable) GETSTRUCT(tp);
+
+ /*
+ * It is also possible that a variable has been dropped and
+ * someone created a new variable with the same object ID. Use
+ * the catalog information only if that is not the case.
+ */
+ if (svar->create_lsn == varform->varcreate_lsn)
+ {
+ values[1] = CStringGetTextDatum(
+ get_namespace_name(varform->varnamespace));
+
+ values[2] = CStringGetTextDatum(NameStr(varform->varname));
+ values[4] = CStringGetTextDatum(format_type_be(svar->typid));
+ values[5] = BoolGetDatum(false);
+
+ values[6] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_SELECT) == ACLCHECK_OK);
+
+ values[7] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_UPDATE) == ACLCHECK_OK);
+
+ var_is_valid = true;
+ }
+
+ ReleaseSysCache(tp);
+ }
+
+ /* if there is no matching catalog entry, return null values */
+ if (!var_is_valid)
+ {
+ nulls[1] = true;
+ nulls[2] = true;
+ nulls[4] = true;
+ values[5] = BoolGetDatum(true);
+ nulls[6] = true;
+ nulls[7] = true;
+ }
+
+ tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
+ }
+ }
+
+ return (Datum) 0;
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 162cd048965..fffc21af420 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -12487,4 +12487,12 @@
proargtypes => 'int4',
prosrc => 'gist_stratnum_common' },
+# Session variables support
+{ oid => '8488', descr => 'list of used session variables',
+ proname => 'pg_session_variables', prorows => '1000', proretset => 't',
+ provolatile => 's', proparallel => 'r', prorettype => 'record',
+ proargtypes => '', proallargtypes => '{oid,text,text,oid,text,bool,bool,bool}',
+ proargmodes => '{o,o,o,o,o,o,o,o}',
+ proargnames => '{varid,schema,name,typid,typname,removed,can_select,can_update}',
+ prosrc => 'pg_session_variables' },
]
--
2.48.1
[text/x-patch] v20250220-0001-Enhancing-catalog-for-support-session-variables-and-.patch (169.3K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/22-v20250220-0001-Enhancing-catalog-for-support-session-variables-and-.patch)
download | inline diff:
From dd6147567437682099dce943c24ac58b8e629b23 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 15:41:55 +0100
Subject: [PATCH 01/21] Enhancing catalog for support session variables and
related support
This patch introduces new system catalog table pg_variable. This table holds metadata about
session variables created by command CREATE VARIABLE, and dropped by command DROP VARIABLE.
Both commands are implemented by this patch. Possibility to change owner, schema or rename.
Access to session variables can be controlled by SELECT or UPDATE rights. Both rights are
introduced by this patch too.
This patch enhancing pg_dump and psql to support session variables. The changes are related
to system catalog.
This patch is not short, but the code is simple.
---
doc/src/sgml/catalogs.sgml | 123 ++++-
doc/src/sgml/ddl.sgml | 40 +-
doc/src/sgml/func.sgml | 32 ++
doc/src/sgml/glossary.sgml | 15 +
doc/src/sgml/ref/allfiles.sgml | 3 +
.../sgml/ref/alter_default_privileges.sgml | 27 +-
doc/src/sgml/ref/alter_variable.sgml | 178 +++++++
doc/src/sgml/ref/comment.sgml | 1 +
doc/src/sgml/ref/create_schema.sgml | 12 +-
doc/src/sgml/ref/create_variable.sgml | 149 ++++++
doc/src/sgml/ref/drop_variable.sgml | 117 +++++
doc/src/sgml/ref/grant.sgml | 20 +-
doc/src/sgml/ref/psql-ref.sgml | 13 +
doc/src/sgml/ref/revoke.sgml | 8 +
doc/src/sgml/reference.sgml | 3 +
src/backend/catalog/Makefile | 1 +
src/backend/catalog/aclchk.c | 77 ++++
src/backend/catalog/dependency.c | 6 +
src/backend/catalog/meson.build | 1 +
src/backend/catalog/namespace.c | 221 +++++++++
src/backend/catalog/objectaddress.c | 121 ++++-
src/backend/catalog/pg_shdepend.c | 2 +
src/backend/catalog/pg_variable.c | 251 ++++++++++
src/backend/commands/alter.c | 9 +
src/backend/commands/dropcmds.c | 4 +
src/backend/commands/event_trigger.c | 4 +
src/backend/commands/seclabel.c | 1 +
src/backend/commands/tablecmds.c | 41 ++
src/backend/commands/typecmds.c | 15 +
src/backend/parser/gram.y | 105 ++++-
src/backend/parser/parse_utilcmd.c | 12 +
src/backend/tcop/utility.c | 20 +
src/backend/utils/adt/acl.c | 221 +++++++++
src/backend/utils/cache/lsyscache.c | 113 +++++
src/bin/pg_dump/common.c | 3 +
src/bin/pg_dump/dumputils.c | 6 +
src/bin/pg_dump/pg_backup.h | 2 +
src/bin/pg_dump/pg_backup_archiver.c | 9 +
src/bin/pg_dump/pg_dump.c | 190 ++++++++
src/bin/pg_dump/pg_dump.h | 15 +
src/bin/pg_dump/pg_dump_sort.c | 7 +
src/bin/pg_dump/t/002_pg_dump.pl | 64 +++
src/bin/psql/command.c | 3 +
src/bin/psql/describe.c | 100 +++-
src/bin/psql/describe.h | 3 +
src/bin/psql/help.c | 1 +
src/bin/psql/tab-complete.in.c | 43 +-
src/include/catalog/Makefile | 3 +-
src/include/catalog/meson.build | 1 +
src/include/catalog/namespace.h | 6 +
src/include/catalog/pg_default_acl.h | 1 +
src/include/catalog/pg_proc.dat | 23 +
src/include/catalog/pg_variable.h | 81 ++++
src/include/nodes/parsenodes.h | 16 +
src/include/parser/kwlist.h | 2 +
src/include/tcop/cmdtaglist.h | 3 +
src/include/utils/acl.h | 1 +
src/include/utils/lsyscache.h | 9 +
src/test/regress/expected/dependency.out | 17 +
src/test/regress/expected/oidjoins.out | 4 +
src/test/regress/expected/psql.out | 50 ++
.../regress/expected/session_variables.out | 433 ++++++++++++++++++
src/test/regress/parallel_schedule | 2 +-
src/test/regress/sql/dependency.sql | 14 +
src/test/regress/sql/psql.sql | 21 +
src/test/regress/sql/session_variables.sql | 297 ++++++++++++
src/tools/pgindent/typedefs.list | 4 +
67 files changed, 3364 insertions(+), 36 deletions(-)
create mode 100644 doc/src/sgml/ref/alter_variable.sgml
create mode 100644 doc/src/sgml/ref/create_variable.sgml
create mode 100644 doc/src/sgml/ref/drop_variable.sgml
create mode 100644 src/backend/catalog/pg_variable.c
create mode 100644 src/include/catalog/pg_variable.h
create mode 100644 src/test/regress/expected/session_variables.out
create mode 100644 src/test/regress/sql/session_variables.sql
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index ee59a7e15d0..7ba91b1f4b1 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -369,6 +369,11 @@
<entry><link linkend="catalog-pg-user-mapping"><structname>pg_user_mapping</structname></link></entry>
<entry>mappings of users to foreign servers</entry>
</row>
+
+ <row>
+ <entry><link linkend="catalog-pg-variable"><structname>pg_variable</structname></link></entry>
+ <entry>session variables</entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -3340,7 +3345,8 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
<literal>S</literal> = sequence,
<literal>f</literal> = function,
<literal>T</literal> = type,
- <literal>n</literal> = schema
+ <literal>n</literal> = schema,
+ <literal>V</literal> = session variable
</para></entry>
</row>
@@ -9758,4 +9764,119 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</table>
</sect1>
+ <sect1 id="catalog-pg-variable">
+ <title><structname>pg_variable</structname></title>
+
+ <indexterm zone="catalog-pg-variable">
+ <primary>pg_variable</primary>
+ </indexterm>
+
+ <para>
+ The catalog <structname>pg_variable</structname> stores information about
+ session variables.
+ </para>
+
+ <table>
+ <title><structname>pg_variable</structname> Columns</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ Column Type
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>oid</structfield> <type>oid</type>
+ </para>
+ <para>
+ Row identifier
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartype</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-type"><structname>pg_type</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the variable's data type
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varname</structfield> <type>name</type>
+ </para>
+ <para>
+ Name of the session variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varnamespace</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the namespace that contains this variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varowner</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ Owner of the variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartypmod</structfield> <type>int4</type>
+ </para>
+ <para>
+ <structfield>vartypmod</structfield> records type-specific data
+ supplied at variable creation time (for example, the maximum
+ length of a <type>varchar</type> column). It is passed to
+ type-specific input functions and length coercion functions.
+ The value will generally be -1 for types that do not need <structfield>vartypmod</structfield>.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcollation</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-collation"><structname>pg_collation</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The defined collation of the variable, or zero if the variable is
+ not of a collatable data type.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varacl</structfield> <type>aclitem[]</type>
+ </para>
+ <para>
+ Access privileges; see
+ <xref linkend="sql-grant"/> and
+ <xref linkend="sql-revoke"/>
+ for details
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+ </sect1>
</chapter>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index ae156b6b1cd..edfb7db24fc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -2020,6 +2020,7 @@ REVOKE ALL ON accounts FROM PUBLIC;
For sequences, this privilege also allows use of the
<function>currval</function> function.
For large objects, this privilege allows the object to be read.
+ For session variables, this privilege allows the object to be read.
</para>
</listitem>
</varlistentry>
@@ -2055,6 +2056,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<function>setval</function> functions.
For large objects, this privilege allows writing or truncating the
object.
+ For session variables, this privilege allows to set a value to the
+ object.
</para>
</listitem>
</varlistentry>
@@ -2298,7 +2301,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal> (and table-like objects),
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2313,7 +2317,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal>,
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2500,6 +2505,12 @@ REVOKE ALL ON accounts FROM PUBLIC;
<entry><literal>U</literal></entry>
<entry><literal>\dT+</literal></entry>
</row>
+ <row>
+ <entry><literal>SESSION VARIABLE</literal></entry>
+ <entry><literal>rw</literal></entry>
+ <entry><literal>none</literal></entry>
+ <entry><literal>\dV+</literal></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -5350,6 +5361,31 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
</para>
</sect1>
+ <sect1 id="ddl-session-variables">
+ <title>Session Variables</title>
+
+ <indexterm zone="ddl-session-variables">
+ <primary>Session variables</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ </indexterm>
+
+ <para>
+ Session variables are database objects that can hold a value.
+ Session variables, like relations, exist within a schema and their access
+ is controlled via <command>GRANT</command> and <command>REVOKE</command>
+ commands. A session variable can be created by the <command>CREATE
+ VARIABLE</command> command.
+ </para>
+
+ <para>
+ The session variable holds value in session memory. This value is private
+ to each session and is released when the session ends.
+ </para>
+ </sect1>
+
<sect1 id="ddl-others">
<title>Other Database Objects</title>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index df32ee0bf5b..acba5962222 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25342,6 +25342,25 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
</para></entry>
</row>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>has_session_variable_privilege</primary>
+ </indexterm>
+ <function>has_session_variable_privilege</function> (
+ <optional> <parameter>user</parameter> <type>name</type> or <type>oid</type>, </optional>
+ <parameter>session_variable</parameter> <type>text</type> or <type>oid</type>,
+ <parameter>privilege</parameter> <type>text</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Does user have privilege for session variable?
+ Allowable privilege types are
+ <literal>SELECT</literal>, and
+ <literal>UPDATE</literal>.
+ </para></entry>
+ </row>
+
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
@@ -25850,6 +25869,19 @@ SELECT relname FROM pg_class WHERE pg_table_is_visible(oid);
Is type (or domain) visible in search path?
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_variable_is_visible</primary>
+ </indexterm>
+ <function>pg_variable_is_visible</function> ( <parameter>variable</parameter> <type>oid</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Is session variable visible in search path?
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index c0f812e3f5e..b921f5a3339 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1669,6 +1669,21 @@
</glossdef>
</glossentry>
+ <glossentry id="glossary-session-variable">
+ <glossterm>Session variable</glossterm>
+ <glossdef>
+ <para>
+ A persistent database object that holds a value in session memory. This
+ value is private to each session and is released when the session ends.
+ Read or write access to session variables is controlled by privileges,
+ similar to other database objects.
+ </para>
+ <para>
+ For more information, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </glossdef>
+ </glossentry>
+
<glossentry id="glossary-shared-memory">
<glossterm>Shared memory</glossterm>
<glossdef>
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index f5be638867a..2f67de3e21b 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -47,6 +47,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY alterType SYSTEM "alter_type.sgml">
<!ENTITY alterUser SYSTEM "alter_user.sgml">
<!ENTITY alterUserMapping SYSTEM "alter_user_mapping.sgml">
+<!ENTITY alterVariable SYSTEM "alter_variable.sgml">
<!ENTITY alterView SYSTEM "alter_view.sgml">
<!ENTITY analyze SYSTEM "analyze.sgml">
<!ENTITY begin SYSTEM "begin.sgml">
@@ -99,6 +100,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY createType SYSTEM "create_type.sgml">
<!ENTITY createUser SYSTEM "create_user.sgml">
<!ENTITY createUserMapping SYSTEM "create_user_mapping.sgml">
+<!ENTITY createVariable SYSTEM "create_variable.sgml">
<!ENTITY createView SYSTEM "create_view.sgml">
<!ENTITY deallocate SYSTEM "deallocate.sgml">
<!ENTITY declare SYSTEM "declare.sgml">
@@ -147,6 +149,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY dropType SYSTEM "drop_type.sgml">
<!ENTITY dropUser SYSTEM "drop_user.sgml">
<!ENTITY dropUserMapping SYSTEM "drop_user_mapping.sgml">
+<!ENTITY dropVariable SYSTEM "drop_variable.sgml">
<!ENTITY dropView SYSTEM "drop_view.sgml">
<!ENTITY end SYSTEM "end.sgml">
<!ENTITY execute SYSTEM "execute.sgml">
diff --git a/doc/src/sgml/ref/alter_default_privileges.sgml b/doc/src/sgml/ref/alter_default_privileges.sgml
index 89aacec4fab..a5852d32566 100644
--- a/doc/src/sgml/ref/alter_default_privileges.sgml
+++ b/doc/src/sgml/ref/alter_default_privileges.sgml
@@ -51,6 +51,11 @@ GRANT { { USAGE | CREATE }
ON SCHEMAS
TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+GRANT { { SELECT | UPDATE }
+ [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+
REVOKE [ GRANT OPTION FOR ]
{ { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER | MAINTAIN }
[, ...] | ALL [ PRIVILEGES ] }
@@ -83,6 +88,12 @@ REVOKE [ GRANT OPTION FOR ]
ON SCHEMAS
FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
[ CASCADE | RESTRICT ]
+
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
+ [ CASCADE | RESTRICT ]
</synopsis>
</refsynopsisdiv>
@@ -117,14 +128,14 @@ REVOKE [ GRANT OPTION FOR ]
<para>
Currently,
only the privileges for schemas, tables (including views and foreign
- tables), sequences, functions, and types (including domains) can be
- altered. For this command, functions include aggregates and procedures.
- The words <literal>FUNCTIONS</literal> and <literal>ROUTINES</literal> are
- equivalent in this command. (<literal>ROUTINES</literal> is preferred
- going forward as the standard term for functions and procedures taken
- together. In earlier PostgreSQL releases, only the
- word <literal>FUNCTIONS</literal> was allowed. It is not possible to set
- default privileges for functions and procedures separately.)
+ tables), sequences, functions, types (including domains), and session
+ variables can be altered. For this command, functions include aggregates
+ and procedures. The words <literal>FUNCTIONS</literal> and
+ <literal>ROUTINES</literal> are equivalent in this command.
+ (<literal>ROUTINES</literal> is preferred going forward as the standard
+ term for functions and procedures taken together. In earlier PostgreSQL
+ releases, only the word <literal>FUNCTIONS</literal> was allowed. It is not
+ possible to set default privileges for functions and procedures separately.)
</para>
<para>
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
new file mode 100644
index 00000000000..96d2586423e
--- /dev/null
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -0,0 +1,178 @@
+<!--
+doc/src/sgml/ref/alter_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-altervariable">
+ <indexterm zone="sql-altervariable">
+ <primary>ALTER VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>altering</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>ALTER VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>ALTER VARIABLE</refname>
+ <refpurpose>
+ change the definition of a session variable
+ </refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable class="parameter">new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable class="parameter">new_name</replaceable>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> SET SCHEMA <replaceable class="parameter">new_schema</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>ALTER VARIABLE</command> command changes the definition of an
+ existing session variable. There are several subforms:
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>OWNER</literal></term>
+ <listitem>
+ <para>
+ This form changes the owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RENAME</literal></term>
+ <listitem>
+ <para>
+ This form changes the name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>SET SCHEMA</literal></term>
+ <listitem>
+ <para>
+ This form moves the session variable into another schema.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </para>
+
+ <para>
+ Only the owner or a superuser is allowed to alter a session variable.
+ In order to move a session variable from one schema to another, the user
+ must also have the <literal>CREATE</literal> privilege on the new schema (or
+ be a superuser).
+
+ In order to move the session variable ownership from one role to another,
+ the user must also be a direct or indirect member of the new
+ owning role, and that role must have the <literal>CREATE</literal> privilege
+ on the session variable's schema (or be a superuser). These restrictions
+ enforce that altering the owner doesn't do anything you couldn't do by
+ dropping and recreating the session variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <para>
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name (possibly schema-qualified) of the existing session variable
+ to alter.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_owner</replaceable></term>
+ <listitem>
+ <para>
+ The user name of the new owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_name</replaceable></term>
+ <listitem>
+ <para>
+ The new name for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_schema</replaceable></term>
+ <listitem>
+ <para>
+ The new schema for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To rename a session variable:
+<programlisting>
+ALTER VARIABLE foo RENAME TO boo;
+</programlisting>
+ </para>
+
+ <para>
+ To change the owner of the session variable <literal>boo</literal> to
+ <literal>joe</literal>:
+<programlisting>
+ALTER VARIABLE boo OWNER TO joe;
+</programlisting>
+ </para>
+
+ <para>
+ To change the schema of the session variable <literal>boo</literal> to
+ <literal>private</literal>:
+<programlisting>
+ALTER VARIABLE boo SET SCHEMA private;
+</programlisting>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ Session variables and this command in particular are a PostgreSQL extension.
+ </para>
+ </refsect1>
+
+ <refsect1 id="sql-altervariable-see-also">
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index 5b43c56b133..21cd80818fb 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -65,6 +65,7 @@ COMMENT ON
TRANSFORM FOR <replaceable>type_name</replaceable> LANGUAGE <replaceable>lang_name</replaceable> |
TRIGGER <replaceable class="parameter">trigger_name</replaceable> ON <replaceable class="parameter">table_name</replaceable> |
TYPE <replaceable class="parameter">object_name</replaceable> |
+ VARIABLE <replaceable class="parameter">object_name</replaceable> |
VIEW <replaceable class="parameter">object_name</replaceable>
} IS { <replaceable class="parameter">string_literal</replaceable> | NULL }
diff --git a/doc/src/sgml/ref/create_schema.sgml b/doc/src/sgml/ref/create_schema.sgml
index ed69298ccc6..d2bb265209b 100644
--- a/doc/src/sgml/ref/create_schema.sgml
+++ b/doc/src/sgml/ref/create_schema.sgml
@@ -103,9 +103,10 @@ CREATE SCHEMA IF NOT EXISTS AUTHORIZATION <replaceable class="parameter">role_sp
schema. Currently, only <command>CREATE
TABLE</command>, <command>CREATE VIEW</command>, <command>CREATE
INDEX</command>, <command>CREATE SEQUENCE</command>, <command>CREATE
- TRIGGER</command> and <command>GRANT</command> are accepted as clauses
- within <command>CREATE SCHEMA</command>. Other kinds of objects may
- be created in separate commands after the schema is created.
+ TRIGGER</command>, <command>GRANT</command> and <command>CREATE
+ VARIABLE</command> are accepted as clauses within <command>CREATE
+ SCHEMA</command>. Other kinds of objects may be created in separate
+ commands after the schema is created.
</para>
</listitem>
</varlistentry>
@@ -214,6 +215,11 @@ CREATE VIEW hollywood.winners AS
The <literal>IF NOT EXISTS</literal> option is a
<productname>PostgreSQL</productname> extension.
</para>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
</refsect1>
<refsect1>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
new file mode 100644
index 00000000000..6e988f2e472
--- /dev/null
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -0,0 +1,149 @@
+<!--
+doc/src/sgml/ref/create_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-createvariable">
+ <indexterm zone="sql-createvariable">
+ <primary>CREATE VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>defining</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>CREATE VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>CREATE VARIABLE</refname>
+ <refpurpose>define a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+</synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command creates a session variable.
+ Session variables, like relations, exist within a schema and their access is
+ controlled via the commands <command>GRANT</command> and <command>REVOKE</command>.
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a session variable's value returns NULL, unless its value is set to
+ something else in the current session with a <command>LET</command> command.
+ The content of a session variable is not transactional. This is the same as
+ regular variables in procedural languages.
+ </para>
+
+ <para>
+ Session variables are retrieved by the <command>SELECT</command>
+ command. Their value is set with the <command>LET</command> command.
+ </para>
+
+ <note>
+ <para>
+ Session variables can be <quote>shadowed</quote> by other identifiers.
+ For details, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </note>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+
+ <varlistentry id="sql-createvariable-if-not-exists">
+ <term><literal>IF NOT EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the name already exists. A notice is issued in
+ this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-name">
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-data_type">
+ <term><replaceable class="parameter">data_type</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the data type of the session
+ variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-collate">
+ <term><literal>COLLATE <replaceable>collation</replaceable></literal></term>
+ <listitem>
+ <para>
+ The <literal>COLLATE</literal> clause assigns a collation to the session
+ variable (which must be of a collatable data type). If not specified,
+ the data type's default collation is used.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para>
+ Use the <command>DROP VARIABLE</command> command to remove a session
+ variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ Create an date session variable <literal>var1</literal>:
+<programlisting>
+CREATE VARIABLE var1 AS date;
+</programlisting>
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
new file mode 100644
index 00000000000..5bdb3560f0b
--- /dev/null
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -0,0 +1,117 @@
+<!--
+doc/src/sgml/ref/drop_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-dropvariable">
+ <indexterm zone="sql-dropvariable">
+ <primary>DROP VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>removing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>DROP VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>DROP VARIABLE</refname>
+ <refpurpose>remove a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+DROP VARIABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ <command>DROP VARIABLE</command> removes a session variable.
+ A session variable can only be removed by its owner or a superuser.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>IF EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the session variable does not exist. A notice is
+ issued in this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of a session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>CASCADE</literal></term>
+ <listitem>
+ <para>
+ Automatically drop objects that depend on the session variable (such as
+ views), and in turn all objects that depend on those objects
+ (see <xref linkend="ddl-depend"/>).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RESTRICT</literal></term>
+ <listitem>
+ <para>
+ Refuse to drop the session variable if any objects depend on it. This is
+ the default.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To remove the session variable <literal>var1</literal>:
+
+<programlisting>
+DROP VARIABLE var1;
+</programlisting></para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>DROP VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index 999f657d5c0..c11860fa200 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -101,6 +101,12 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
[ WITH { ADMIN | INHERIT | SET } { OPTION | TRUE | FALSE } ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+GRANT { SELECT | UPDATE | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
@@ -119,8 +125,8 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
that grants privileges on a database object (table, column, view,
foreign table, sequence, database, foreign-data wrapper, foreign server,
function, procedure, procedural language, large object, configuration
- parameter, schema, tablespace, or type), and one that grants
- membership in a role. These variants are similar in many ways, but
+ parameter, schema, session variable, tablespace, or type), and one that
+ grants membership in a role. These variants are similar in many ways, but
they are different enough to be described separately.
</para>
@@ -236,9 +242,9 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
<para>
There is also an option to grant privileges on all objects of the same
type within one or more schemas. This functionality is currently supported
- only for tables, sequences, functions, and procedures. <literal>ALL
- TABLES</literal> also affects views and foreign tables, just like the
- specific-object <command>GRANT</command> command. <literal>ALL
+ only for tables, sequences, functions, procedures and variables.
+ <literal>ALL TABLES</literal> also affects views and foreign tables, just
+ like the specific-object <command>GRANT</command> command. <literal>ALL
FUNCTIONS</literal> also affects aggregate and window functions, but not
procedures, again just like the specific-object <command>GRANT</command>
command. Use <literal>ALL ROUTINES</literal> to include procedures.
@@ -518,8 +524,8 @@ GRANT admins TO joe;
</para>
<para>
- Privileges on databases, tablespaces, schemas, languages, and
- configuration parameters are
+ Privileges on databases, tablespaces, schemas, languages, session variables
+ and configuration parameters are
<productname>PostgreSQL</productname> extensions.
</para>
</refsect1>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index f3044fac1fa..da9ef01ddea 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -2134,6 +2134,19 @@ SELECT $1 \parse stmt1
</listitem>
</varlistentry>
+ <varlistentry id="app-psql-meta-command-dv">
+ <term><literal>\dV[+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
+ <listitem>
+ <para>
+ Lists session variables.
+ If <replaceable class="parameter">pattern</replaceable> is
+ specified, only session variables whose names match the pattern are listed.
+ If the form <literal>\dV+</literal> is used, additional information
+ about each variable is shown, like access privileges and description.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="app-psql-meta-command-du">
<term><literal>\du[Sx+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
<listitem>
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index 8df492281a1..760fddb7c20 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -130,6 +130,14 @@ REVOKE [ { ADMIN | INHERIT | SET } OPTION FOR ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
[ CASCADE | RESTRICT ]
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ FROM { <replaceable class="parameter">role_specification</replaceable> | PUBLIC } [, ...]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+ [ CASCADE | RESTRICT ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index ff85ace83fc..25578f3946c 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -75,6 +75,7 @@
&alterType;
&alterUser;
&alterUserMapping;
+ &alterVariable;
&alterView;
&analyze;
&begin;
@@ -127,6 +128,7 @@
&createType;
&createUser;
&createUserMapping;
+ &createVariable;
&createView;
&deallocate;
&declare;
@@ -175,6 +177,7 @@
&dropType;
&dropUser;
&dropUserMapping;
+ &dropVariable;
&dropView;
&end;
&execute;
diff --git a/src/backend/catalog/Makefile b/src/backend/catalog/Makefile
index c090094ed08..2c20d60db19 100644
--- a/src/backend/catalog/Makefile
+++ b/src/backend/catalog/Makefile
@@ -45,6 +45,7 @@ OBJS = \
pg_shdepend.o \
pg_subscription.o \
pg_type.o \
+ pg_variable.o \
storage.o \
toasting.o
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 02a754cc30a..1e8ce752b90 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -64,6 +64,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -291,6 +292,9 @@ restrict_and_check_grant(bool is_grant, AclMode avail_goptions, bool all_privs,
case OBJECT_PARAMETER_ACL:
whole_mask = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ whole_mask = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", objtype);
/* not reached, but keep compiler quiet */
@@ -535,6 +539,10 @@ ExecuteGrantStmt(GrantStmt *stmt)
all_privileges = ACL_ALL_RIGHTS_PARAMETER_ACL;
errormsg = gettext_noop("invalid privilege type %s for parameter");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) stmt->objtype);
@@ -640,6 +648,9 @@ ExecGrantStmt_oids(InternalGrant *istmt)
case OBJECT_PARAMETER_ACL:
ExecGrant_Parameter(istmt);
break;
+ case OBJECT_VARIABLE:
+ ExecGrant_common(istmt, VariableRelationId, ACL_ALL_RIGHTS_VARIABLE, NULL);
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) istmt->objtype);
@@ -760,6 +771,18 @@ objectNamesToOids(ObjectType objtype, List *objnames, bool is_grant)
objects = lappend_oid(objects, parameterId);
}
break;
+
+ case OBJECT_VARIABLE:
+ foreach_node(RangeVar, varvar, objnames)
+ {
+ Oid relOid;
+
+ relOid = LookupVariable(varvar->schemaname,
+ varvar->relname,
+ false);
+ objects = lappend_oid(objects, relOid);
+ }
+ break;
}
return objects;
@@ -846,6 +869,32 @@ objectsInSchemaToOids(ObjectType objtype, List *nspnames)
table_close(rel, AccessShareLock);
}
break;
+ case OBJECT_VARIABLE:
+ {
+ ScanKeyData key;
+ Relation rel;
+ TableScanDesc scan;
+ HeapTuple tuple;
+
+ ScanKeyInit(&key,
+ Anum_pg_variable_varnamespace,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(namespaceId));
+
+ rel = table_open(VariableRelationId, AccessShareLock);
+ scan = table_beginscan_catalog(rel, 1, &key);
+
+ while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+ {
+ Oid oid = ((Form_pg_proc) GETSTRUCT(tuple))->oid;
+
+ objects = lappend_oid(objects, oid);
+ }
+
+ table_endscan(scan);
+ table_close(rel, AccessShareLock);
+ }
+ break;
default:
/* should not happen */
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
@@ -1005,6 +1054,10 @@ ExecAlterDefaultPrivilegesStmt(ParseState *pstate, AlterDefaultPrivilegesStmt *s
all_privileges = ACL_ALL_RIGHTS_SCHEMA;
errormsg = gettext_noop("invalid privilege type %s for schema");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) action->objtype);
@@ -1196,6 +1249,12 @@ SetDefaultACL(InternalDefaultACL *iacls)
this_privileges = ACL_ALL_RIGHTS_SCHEMA;
break;
+ case OBJECT_VARIABLE:
+ objtype = DEFACLOBJ_VARIABLE;
+ if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
+ this_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ break;
+
default:
elog(ERROR, "unrecognized object type: %d",
(int) iacls->objtype);
@@ -1439,6 +1498,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case DEFACLOBJ_NAMESPACE:
iacls.objtype = OBJECT_SCHEMA;
break;
+ case DEFACLOBJ_VARIABLE:
+ iacls.objtype = OBJECT_VARIABLE;
+ break;
default:
/* Shouldn't get here */
elog(ERROR, "unexpected default ACL type: %d",
@@ -1499,6 +1561,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case ParameterAclRelationId:
istmt.objtype = OBJECT_PARAMETER_ACL;
break;
+ case VariableRelationId:
+ istmt.objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unexpected object class %u", classid);
break;
@@ -2732,6 +2797,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("permission denied for type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("permission denied for session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("permission denied for view %s");
break;
@@ -2843,6 +2911,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("must be owner of type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("must be owner of session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("must be owner of view %s");
break;
@@ -2991,6 +3062,8 @@ pg_aclmask(ObjectType objtype, Oid object_oid, AttrNumber attnum, Oid roleid,
return ACL_NO_RIGHTS;
case OBJECT_TYPE:
return object_aclmask(TypeRelationId, object_oid, roleid, mask, how);
+ case OBJECT_VARIABLE:
+ return object_aclmask(VariableRelationId, object_oid, roleid, mask, how);
default:
elog(ERROR, "unrecognized object type: %d",
(int) objtype);
@@ -4250,6 +4323,10 @@ get_user_default_acl(ObjectType objtype, Oid ownerId, Oid nsp_oid)
defaclobjtype = DEFACLOBJ_NAMESPACE;
break;
+ case OBJECT_VARIABLE:
+ defaclobjtype = DEFACLOBJ_VARIABLE;
+ break;
+
default:
return NULL;
}
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 18316a3968b..9e0f648b74f 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -65,12 +65,14 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/comment.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "commands/extension.h"
#include "commands/policy.h"
#include "commands/publicationcmds.h"
+#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
#include "commands/trigger.h"
@@ -1444,6 +1446,10 @@ doDeletion(const ObjectAddress *object, int flags)
RemovePublicationById(object->objectId);
break;
+ case VariableRelationId:
+ DropVariableById(object->objectId);
+ break;
+
case CastRelationId:
case CollationRelationId:
case ConversionRelationId:
diff --git a/src/backend/catalog/meson.build b/src/backend/catalog/meson.build
index 1958ea9238a..ed44c877fca 100644
--- a/src/backend/catalog/meson.build
+++ b/src/backend/catalog/meson.build
@@ -32,6 +32,7 @@ backend_sources += files(
'pg_shdepend.c',
'pg_subscription.c',
'pg_type.c',
+ 'pg_variable.c',
'storage.c',
'toasting.c',
)
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index d97d632a7ef..4307cad15c7 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "common/hashfn_unstable.h"
#include "funcapi.h"
@@ -225,6 +226,7 @@ static bool TSParserIsVisibleExt(Oid prsId, bool *is_missing);
static bool TSDictionaryIsVisibleExt(Oid dictId, bool *is_missing);
static bool TSTemplateIsVisibleExt(Oid tmplId, bool *is_missing);
static bool TSConfigIsVisibleExt(Oid cfgid, bool *is_missing);
+static bool VariableIsVisibleExt(Oid varid, bool *is_missing);
static void recomputeNamespacePath(void);
static void AccessTempTableNamespace(bool force);
static void InitTempTableNamespace(void);
@@ -986,6 +988,84 @@ RelationIsVisibleExt(Oid relid, bool *is_missing)
return visible;
}
+/*
+ * VariableIsVisible
+ * Determine whether a variable (identified by OID) is visible in the
+ * current search path. Visible means "would be found by searching
+ * for the unqualified variable name".
+ */
+bool
+VariableIsVisible(Oid varid)
+{
+ return VariableIsVisibleExt(varid, NULL);
+}
+
+/*
+ * VariableIsVisibleExt
+ * As above, but if the variable isn't found and is_missing is not NULL,
+ * then set *is_missing = true and return false, instead of throwing
+ * an error. (Caller must initialize *is_missing = false.)
+ */
+static bool
+VariableIsVisibleExt(Oid varid, bool *is_missing)
+{
+ HeapTuple vartup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+ bool visible;
+
+ vartup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+ if (!HeapTupleIsValid(vartup))
+ {
+ if (is_missing != NULL)
+ {
+ *is_missing = true;
+ return false;
+ }
+
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+ }
+ varform = (Form_pg_variable) GETSTRUCT(vartup);
+
+ recomputeNamespacePath();
+
+ /*
+ * Quick check: if it ain't in the path at all, it ain't visible. We
+ * don't expect usage of session variables in the system namespace.
+ */
+ varnamespace = varform->varnamespace;
+ if (!list_member_oid(activeSearchPath, varnamespace))
+ visible = false;
+ else
+ {
+ /*
+ * If it is in the path, it might still not be visible; it could be
+ * hidden by another variable of the same name earlier in the path. So
+ * we must do a slow check for conflicting relations.
+ */
+ char *varname = NameStr(varform->varname);
+
+ visible = false;
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ if (namespaceId == varnamespace)
+ {
+ /* found it first in path */
+ visible = true;
+ break;
+ }
+ if (OidIsValid(get_varname_varid(varname, namespaceId)))
+ {
+ /* found something else first in path */
+ break;
+ }
+ }
+ }
+
+ ReleaseSysCache(vartup);
+
+ return visible;
+}
/*
* TypenameGetTypid
@@ -3289,6 +3369,133 @@ TSConfigIsVisibleExt(Oid cfgid, bool *is_missing)
return visible;
}
+/*
+ * Returns oid of session variable specified by possibly qualified identifier.
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariable(const char *nspname,
+ const char *varname,
+ bool missing_ok)
+{
+ Oid varoid = InvalidOid;
+
+ if (nspname)
+ {
+ Oid namespaceId = LookupExplicitNamespace(nspname, missing_ok);
+
+ /* if nspname is a known namespace, the variable must be there */
+ if (OidIsValid(namespaceId))
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+ }
+ }
+ else
+ {
+ /* iterate over the schemas on the search_path */
+ recomputeNamespacePath();
+
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+
+ if (OidIsValid(varoid))
+ break;
+ }
+ }
+
+ if (!OidIsValid(varoid) && !missing_ok)
+ {
+ if (nspname)
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s.%s\" does not exist",
+ nspname, varname)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" does not exist",
+ varname)));
+ }
+
+ return varoid;
+}
+
+/*
+ * Returns oid of session variable specified by possibly qualified identifier
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariableFromNameList(List *names,
+ bool missing_ok)
+{
+ char *catname = NULL;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ switch (list_length(names))
+ {
+ case 1:
+ varname = strVal(linitial(names));
+ break;
+ case 2:
+ nspname = strVal(linitial(names));
+ varname = strVal(lsecond(names));
+ break;
+ case 3:
+ catname = strVal(linitial(names));
+ nspname = strVal(lsecond(names));
+ varname = strVal(lthird(names));
+
+ /* check catalog name */
+ if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ break;
+ default:
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper session variable name (too many dotted names): %s",
+ NameListToString(names))));
+ break;
+ }
+
+ return LookupVariable(nspname, varname, missing_ok);
+}
+
+/*
+ * The input list contains names with indirection expressions used as the left
+ * part of LET statement. The following routine returns a new list with only
+ * initial strings (names) - without indirection expressions.
+ */
+List *
+NamesFromList(List *names)
+{
+ ListCell *l;
+ List *result = NIL;
+
+ foreach(l, names)
+ {
+ Node *n = lfirst(l);
+
+ if (IsA(n, String))
+ {
+ result = lappend(result, n);
+ }
+ else
+ break;
+ }
+
+ return result;
+}
/*
* DeconstructQualifiedName
@@ -5085,3 +5292,17 @@ pg_is_other_temp_schema(PG_FUNCTION_ARGS)
PG_RETURN_BOOL(isOtherTempNamespace(oid));
}
+
+Datum
+pg_variable_is_visible(PG_FUNCTION_ARGS)
+{
+ Oid oid = PG_GETARG_OID(0);
+ bool result;
+ bool is_missing = false;
+
+ result = VariableIsVisibleExt(oid, &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+ PG_RETURN_BOOL(result);
+}
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index d8eb8d3deaa..4a464dfea7e 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -62,6 +62,7 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -636,6 +637,20 @@ static const ObjectPropertyType ObjectProperty[] =
OBJECT_USER_MAPPING,
false
},
+ {
+ "session variable",
+ VariableRelationId,
+ VariableOidIndexId,
+ VARIABLEOID,
+ VARIABLENAMENSP,
+ Anum_pg_variable_oid,
+ Anum_pg_variable_varname,
+ Anum_pg_variable_varnamespace,
+ Anum_pg_variable_varowner,
+ Anum_pg_variable_varacl,
+ OBJECT_VARIABLE,
+ true
+ }
};
/*
@@ -831,6 +846,9 @@ static const struct object_type_map
},
{
"statistics object", OBJECT_STATISTIC_EXT
+ },
+ {
+ "session variable", OBJECT_VARIABLE
}
};
@@ -856,6 +874,7 @@ static ObjectAddress get_object_address_attrdef(ObjectType objtype,
bool missing_ok);
static ObjectAddress get_object_address_type(ObjectType objtype,
TypeName *typename, bool missing_ok);
+static ObjectAddress get_object_address_variable(List *object, bool missing_ok);
static ObjectAddress get_object_address_opcf(ObjectType objtype, List *object,
bool missing_ok);
static ObjectAddress get_object_address_opf_member(ObjectType objtype,
@@ -1127,6 +1146,9 @@ get_object_address(ObjectType objtype, Node *object,
missing_ok);
address.objectSubId = 0;
break;
+ case OBJECT_VARIABLE:
+ address = get_object_address_variable(castNode(List, object), missing_ok);
+ break;
/* no default, to let compiler warn about missing case */
}
@@ -2005,16 +2027,20 @@ get_object_address_defacl(List *object, bool missing_ok)
case DEFACLOBJ_NAMESPACE:
objtype_str = "schemas";
break;
+ case DEFACLOBJ_VARIABLE:
+ objtype_str = "variables";
+ break;
default:
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized default ACL object type \"%c\"", objtype),
- errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
+ errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
DEFACLOBJ_RELATION,
DEFACLOBJ_SEQUENCE,
DEFACLOBJ_FUNCTION,
DEFACLOBJ_TYPE,
- DEFACLOBJ_NAMESPACE)));
+ DEFACLOBJ_NAMESPACE,
+ DEFACLOBJ_VARIABLE)));
}
/*
@@ -2098,6 +2124,24 @@ textarray_to_strvaluelist(ArrayType *arr)
return list;
}
+/*
+ * Find the ObjectAddress for a session variable
+ */
+static ObjectAddress
+get_object_address_variable(List *object, bool missing_ok)
+{
+ ObjectAddress address;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ ObjectAddressSet(address, VariableRelationId, InvalidOid);
+
+ DeconstructQualifiedName(object, &nspname, &varname);
+ address.objectId = LookupVariable(nspname, varname, missing_ok);
+
+ return address;
+}
+
/*
* SQL-callable version of get_object_address
*/
@@ -2292,6 +2336,7 @@ pg_get_object_address(PG_FUNCTION_ARGS)
case OBJECT_TABCONSTRAINT:
case OBJECT_OPCLASS:
case OBJECT_OPFAMILY:
+ case OBJECT_VARIABLE:
objnode = (Node *) name;
break;
case OBJECT_ACCESS_METHOD:
@@ -2463,6 +2508,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
case OBJECT_STATISTIC_EXT:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
if (!object_ownercheck(address.classId, address.objectId, roleid))
aclcheck_error(ACLCHECK_NOT_OWNER, objtype,
NameListToString(castNode(List, object)));
@@ -3492,6 +3538,32 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
break;
}
+ case VariableRelationId:
+ {
+ char *nspname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ if (VariableIsVisible(object->objectId))
+ nspname = NULL;
+ else
+ nspname = get_namespace_name(varform->varnamespace);
+
+ appendStringInfo(&buffer, _("session variable %s"),
+ quote_qualified_identifier(nspname,
+ NameStr(varform->varname)));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
case TSParserRelationId:
{
HeapTuple tup;
@@ -3844,6 +3916,16 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
_("default privileges on new schemas belonging to role %s"),
rolename);
break;
+ case DEFACLOBJ_VARIABLE:
+ if (nspname)
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s in schema %s"),
+ rolename, nspname);
+ else
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s"),
+ rolename);
+ break;
default:
/* shouldn't get here */
if (nspname)
@@ -4660,6 +4742,10 @@ getObjectTypeDescription(const ObjectAddress *object, bool missing_ok)
appendStringInfoString(&buffer, "transform");
break;
+ case VariableRelationId:
+ appendStringInfoString(&buffer, "session variable");
+ break;
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
@@ -5766,6 +5852,10 @@ getObjectIdentityParts(const ObjectAddress *object,
appendStringInfoString(&buffer,
" on schemas");
break;
+ case DEFACLOBJ_VARIABLE:
+ appendStringInfoString(&buffer,
+ " on session variables");
+ break;
}
if (objname)
@@ -6006,6 +6096,33 @@ getObjectIdentityParts(const ObjectAddress *object,
}
break;
+ case VariableRelationId:
+ {
+ char *schema;
+ char *varname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ schema = get_namespace_name_or_temp(varform->varnamespace);
+ varname = NameStr(varform->varname);
+
+ appendStringInfo(&buffer, "%s",
+ quote_qualified_identifier(schema, varname));
+
+ if (objname)
+ *objname = list_make2(schema, pstrdup(varname));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
diff --git a/src/backend/catalog/pg_shdepend.c b/src/backend/catalog/pg_shdepend.c
index 536191284e8..c6fd1fa074f 100644
--- a/src/backend/catalog/pg_shdepend.c
+++ b/src/backend/catalog/pg_shdepend.c
@@ -46,6 +46,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
@@ -1714,6 +1715,7 @@ shdepReassignOwned_Owner(Form_pg_shdepend sdepForm, Oid newrole)
case DatabaseRelationId:
case TSConfigRelationId:
case TSDictionaryRelationId:
+ case VariableRelationId:
AlterObjectOwner_internal(sdepForm->classid,
sdepForm->objid,
newrole);
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
new file mode 100644
index 00000000000..29d967a2d5b
--- /dev/null
+++ b/src/backend/catalog/pg_variable.c
@@ -0,0 +1,251 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.c
+ * session variables
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/catalog/pg_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "catalog/dependency.h"
+#include "catalog/indexing.h"
+#include "catalog/namespace.h"
+#include "catalog/objectaccess.h"
+#include "catalog/pg_collation.h"
+#include "catalog/pg_namespace.h"
+#include "catalog/pg_variable.h"
+#include "miscadmin.h"
+#include "parser/parse_type.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+static ObjectAddress create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists);
+
+
+/*
+ * Creates entry in pg_variable table
+ */
+static ObjectAddress
+create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists)
+{
+ Acl *varacl;
+ NameData varname;
+ bool nulls[Natts_pg_variable];
+ Datum values[Natts_pg_variable];
+ Relation rel;
+ HeapTuple tup;
+ TupleDesc tupdesc;
+ ObjectAddress myself,
+ referenced;
+ ObjectAddresses *addrs;
+ Oid varid;
+
+ Assert(varName);
+ Assert(OidIsValid(varNamespace));
+ Assert(OidIsValid(varType));
+ Assert(OidIsValid(varOwner));
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ /*
+ * Check for duplicates. Note that this does not really prevent
+ * duplicates, it's here just to provide nicer error message in common
+ * case. The real protection is the unique key on the catalog.
+ */
+ if (SearchSysCacheExists2(VARIABLENAMENSP,
+ PointerGetDatum(varName),
+ ObjectIdGetDatum(varNamespace)))
+ {
+ if (if_not_exists)
+ ereport(NOTICE,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists, skipping",
+ varName)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists",
+ varName)));
+
+ table_close(rel, RowExclusiveLock);
+
+ return InvalidObjectAddress;
+ }
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, false, sizeof(nulls));
+
+ namestrcpy(&varname, varName);
+
+ varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
+
+ values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
+ values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
+ values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
+ values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
+ values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
+ values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+
+ varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
+ varNamespace);
+ if (varacl != NULL)
+ values[Anum_pg_variable_varacl - 1] = PointerGetDatum(varacl);
+ else
+ nulls[Anum_pg_variable_varacl - 1] = true;
+
+ tupdesc = RelationGetDescr(rel);
+
+ tup = heap_form_tuple(tupdesc, values, nulls);
+ CatalogTupleInsert(rel, tup);
+ Assert(OidIsValid(varid));
+
+ addrs = new_object_addresses();
+
+ ObjectAddressSet(myself, VariableRelationId, varid);
+
+ /* dependency on namespace */
+ ObjectAddressSet(referenced, NamespaceRelationId, varNamespace);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on used type */
+ ObjectAddressSet(referenced, TypeRelationId, varType);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on collation */
+ if (OidIsValid(varCollation) &&
+ varCollation != DEFAULT_COLLATION_OID)
+ {
+ ObjectAddressSet(referenced, CollationRelationId, varCollation);
+ add_exact_object_address(&referenced, addrs);
+ }
+
+ record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
+ free_object_addresses(addrs);
+
+ /* dependency on owner */
+ recordDependencyOnOwner(VariableRelationId, varid, varOwner);
+
+ /* dependencies on roles mentioned in default ACL */
+ recordDependencyOnNewAcl(VariableRelationId, varid, 0, varOwner, varacl);
+
+ /* dependency on extension */
+ recordDependencyOnCurrentExtension(&myself, false);
+
+ heap_freetuple(tup);
+
+ /* post creation hook for new function */
+ InvokeObjectPostCreateHook(VariableRelationId, varid, 0);
+
+ table_close(rel, RowExclusiveLock);
+
+ return myself;
+}
+
+/*
+ * Creates a new variable
+ *
+ * Used by CREATE VARIABLE command
+ */
+ObjectAddress
+CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
+{
+ Oid namespaceid;
+ AclResult aclresult;
+ Oid typid;
+ int32 typmod;
+ Oid varowner = GetUserId();
+ Oid collation;
+ Oid typcollation;
+ ObjectAddress variable;
+
+ namespaceid =
+ RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL);
+
+ typenameTypeIdAndMod(pstate, stmt->typeName, &typid, &typmod);
+
+ /* disallow pseudotypes */
+ if (get_typtype(typid) == TYPTYPE_PSEUDO)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("session variable cannot be pseudo-type %s",
+ format_type_be(typid))));
+
+ aclresult = object_aclcheck(TypeRelationId, typid, GetUserId(), ACL_USAGE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error_type(aclresult, typid);
+
+ typcollation = get_typcollation(typid);
+
+ if (stmt->collClause)
+ collation = LookupCollation(pstate,
+ stmt->collClause->collname,
+ stmt->collClause->location);
+ else
+ collation = typcollation;
+
+ /* complain if COLLATE is applied to an uncollatable type */
+ if (OidIsValid(collation) && !OidIsValid(typcollation))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("collations are not supported by type %s",
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->collClause->location)));
+
+ variable = create_variable(stmt->variable->relname,
+ namespaceid,
+ typid,
+ typmod,
+ varowner,
+ collation,
+ stmt->if_not_exists);
+
+ elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
+ stmt->variable->relname, variable.objectId);
+
+ return variable;
+}
+
+/*
+ * Drop variable by OID
+ */
+void
+DropVariableById(Oid varid)
+{
+ Relation rel;
+ HeapTuple tup;
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ CatalogTupleDelete(rel, &tup->t_self);
+
+ ReleaseSysCache(tup);
+
+ table_close(rel, RowExclusiveLock);
+}
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 78c1d4e1b84..67153cd8b94 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/collationcmds.h"
#include "commands/dbcommands.h"
@@ -140,6 +141,10 @@ report_namespace_conflict(Oid classId, const char *name, Oid nspOid)
Assert(OidIsValid(nspOid));
msgfmt = gettext_noop("text search configuration \"%s\" already exists in schema \"%s\"");
break;
+ case VariableRelationId:
+ Assert(OidIsValid(nspOid));
+ msgfmt = gettext_noop("session variable \"%s\" already exists in schema \"%s\"");
+ break;
default:
elog(ERROR, "unsupported object class: %u", classId);
break;
@@ -419,6 +424,7 @@ ExecRenameStmt(RenameStmt *stmt)
case OBJECT_TSTEMPLATE:
case OBJECT_PUBLICATION:
case OBJECT_SUBSCRIPTION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
Relation catalog;
@@ -559,6 +565,7 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt,
case OBJECT_TSDICTIONARY:
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
+ case OBJECT_VARIABLE:
{
Relation catalog;
Oid classId;
@@ -641,6 +648,7 @@ AlterObjectNamespace_oid(Oid classId, Oid objid, Oid nspOid,
case TSDictionaryRelationId:
case TSTemplateRelationId:
case TSConfigRelationId:
+ case VariableRelationId:
{
Relation catalog;
@@ -871,6 +879,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
case OBJECT_TABLESPACE:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
diff --git a/src/backend/commands/dropcmds.c b/src/backend/commands/dropcmds.c
index ceb9a229b63..ebb585dc4a1 100644
--- a/src/backend/commands/dropcmds.c
+++ b/src/backend/commands/dropcmds.c
@@ -476,6 +476,10 @@ does_not_exist_skipping(ObjectType objtype, Node *object)
msg = gettext_noop("publication \"%s\" does not exist, skipping");
name = strVal(object);
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("session variable \"%s\" does not exist, skipping");
+ name = NameListToString(castNode(List, object));
+ break;
case OBJECT_COLUMN:
case OBJECT_DATABASE:
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index edc2c988e29..1839c1f82c5 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -2149,6 +2149,8 @@ stringify_grant_objtype(ObjectType objtype)
return "TABLESPACE";
case OBJECT_TYPE:
return "TYPE";
+ case OBJECT_VARIABLE:
+ return "VARIABLE";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
@@ -2232,6 +2234,8 @@ stringify_adefprivs_objtype(ObjectType objtype)
return "TABLESPACES";
case OBJECT_TYPE:
return "TYPES";
+ case OBJECT_VARIABLE:
+ return "VARIABLES";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
diff --git a/src/backend/commands/seclabel.c b/src/backend/commands/seclabel.c
index cee5d7bbb9c..57b4e6719c2 100644
--- a/src/backend/commands/seclabel.c
+++ b/src/backend/commands/seclabel.c
@@ -92,6 +92,7 @@ SecLabelSupportsObjectType(ObjectType objtype)
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
case OBJECT_USER_MAPPING:
+ case OBJECT_VARIABLE:
return false;
/*
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 9d8754be7e5..d64ec80096e 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -52,6 +52,7 @@
#include "catalog/pg_tablespace.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "catalog/storage.h"
#include "catalog/storage_xlog.h"
#include "catalog/toasting.h"
@@ -6824,6 +6825,7 @@ ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
* (possibly nested several levels deep in composite types, arrays, etc!).
* Eventually, we'd like to propagate the check or rewrite operation
* into such tables, but for now, just error out if we find any.
+ * Also, check if "typeOid" is used as type of some session variable.
*
* Caller should provide either the associated relation of a rowtype,
* or a type name (not both) for use in the error message, if any.
@@ -6887,6 +6889,45 @@ find_composite_type_dependencies(Oid typeOid, Relation origRelation,
continue;
}
+ /* check if the type is used as type of some session variable */
+ if (pg_depend->classid == VariableRelationId)
+ {
+ Oid varid = pg_depend->objid;
+
+ if (origTypeName)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ origTypeName,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter foreign table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_RELATION ||
+ origRelation->rd_rel->relkind == RELKIND_MATVIEW ||
+ origRelation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+
+ continue;
+ }
+
/* Else, ignore dependees that aren't relations */
if (pg_depend->classid != RelationRelationId)
continue;
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 3cb3ca1cca1..473d98ff062 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -53,6 +53,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_range.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablecmds.h"
#include "commands/typecmds.h"
@@ -3369,6 +3370,20 @@ get_rels_with_domain(Oid domainOid, LOCKMODE lockmode)
}
continue;
}
+ else if (pg_depend->classid == VariableRelationId)
+ {
+ /*
+ * We cannot to validate constraint inside session variables
+ * from other sessions, so better to fail if there are any
+ * session variable, that use this domain.
+ */
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter domain \"%s\" because session variable \"%s.%s\" uses it",
+ domainTypeName,
+ get_namespace_name(get_session_variable_namespace(pg_depend->objid)),
+ get_session_variable_name(pg_depend->objid))));
+ }
/* Else, ignore dependees that aren't user columns of relations */
/* (we assume system columns are never of domain types) */
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 7d99c9355c6..6c95950b99b 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -52,6 +52,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_am.h"
#include "catalog/pg_trigger.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/trigger.h"
#include "gramparse.h"
@@ -285,8 +286,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
ConstraintsSetStmt CopyStmt CreateAsStmt CreateCastStmt
CreateDomainStmt CreateExtensionStmt CreateGroupStmt CreateOpClassStmt
CreateOpFamilyStmt AlterOpFamilyStmt CreatePLangStmt
- CreateSchemaStmt CreateSeqStmt CreateStmt CreateStatsStmt CreateTableSpaceStmt
- CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
+ CreateSchemaStmt CreateSeqStmt CreateSessionVarStmt CreateStmt CreateStatsStmt
+ CreateTableSpaceStmt CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
CreateAssertionStmt CreateTransformStmt CreateTrigStmt CreateEventTrigStmt
CreateUserStmt CreateUserMappingStmt CreateRoleStmt CreatePolicyStmt
CreatedbStmt DeclareCursorStmt DefineStmt DeleteStmt DiscardStmt DoStmt
@@ -783,8 +784,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
UESCAPE UNBOUNDED UNCONDITIONAL UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN
UNLISTEN UNLOGGED UNTIL UPDATE USER USING
- VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
- VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
+ VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARIABLE
+ VARIABLES VARYING VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
@@ -1050,6 +1051,7 @@ stmt:
| CreatePolicyStmt
| CreatePLangStmt
| CreateSchemaStmt
+ | CreateSessionVarStmt
| CreateSeqStmt
| CreateStmt
| CreateSubscriptionStmt
@@ -1592,6 +1594,7 @@ schema_stmt:
| CreateTrigStmt
| GrantStmt
| ViewStmt
+ | CreateSessionVarStmt
;
@@ -5245,6 +5248,34 @@ create_extension_opt_item:
}
;
+/*****************************************************************************
+ *
+ * QUERY :
+ * CREATE VARIABLE varname [AS] type
+ *
+ *****************************************************************************/
+
+CreateSessionVarStmt:
+ CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $3;
+ n->typeName = $5;
+ n->collClause = (CollateClause *) $6;
+ n->if_not_exists = false;
+ $$ = (Node *) n;
+ }
+ | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $6;
+ n->typeName = $8;
+ n->collClause = (CollateClause *) $9;
+ n->if_not_exists = true;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
@@ -7036,6 +7067,7 @@ object_type_any_name:
| TEXT_P SEARCH DICTIONARY { $$ = OBJECT_TSDICTIONARY; }
| TEXT_P SEARCH TEMPLATE { $$ = OBJECT_TSTEMPLATE; }
| TEXT_P SEARCH CONFIGURATION { $$ = OBJECT_TSCONFIGURATION; }
+ | VARIABLE { $$ = OBJECT_VARIABLE; }
;
/*
@@ -7912,6 +7944,14 @@ privilege_target:
n->objs = $2;
$$ = n;
}
+ | VARIABLE qualified_name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_OBJECT;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $2;
+ $$ = n;
+ }
| ALL TABLES IN_P SCHEMA name_list
{
PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
@@ -7957,6 +7997,14 @@ privilege_target:
n->objs = $5;
$$ = n;
}
+ | ALL VARIABLES IN_P SCHEMA name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_ALL_IN_SCHEMA;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $5;
+ $$ = n;
+ }
;
@@ -8154,6 +8202,7 @@ defacl_privilege_target:
| SEQUENCES { $$ = OBJECT_SEQUENCE; }
| TYPES_P { $$ = OBJECT_TYPE; }
| SCHEMAS { $$ = OBJECT_SCHEMA; }
+ | VARIABLES { $$ = OBJECT_VARIABLE; }
;
@@ -9942,6 +9991,24 @@ RenameStmt: ALTER AGGREGATE aggregate_with_argtypes RENAME TO name
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newname = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newname = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
opt_column: COLUMN
@@ -10303,6 +10370,24 @@ AlterObjectSchemaStmt:
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newschema = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newschema = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
/*****************************************************************************
@@ -10584,6 +10669,14 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec
n->newowner = $6;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name OWNER TO RoleSpec
+ {
+ AlterOwnerStmt *n = makeNode(AlterOwnerStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newowner = $6;
+ $$ = (Node *)n;
+ }
;
@@ -17993,6 +18086,8 @@ unreserved_keyword:
| VALIDATE
| VALIDATOR
| VALUE_P
+ | VARIABLE
+ | VARIABLES
| VARYING
| VERSION_P
| VIEW
@@ -18648,6 +18743,8 @@ bare_label_keyword:
| VALUE_P
| VALUES
| VARCHAR
+ | VARIABLE
+ | VARIABLES
| VARIADIC
| VERBOSE
| VERSION_P
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index abbe1bb45a3..14ed3cd9b3e 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -105,6 +105,7 @@ typedef struct
List *indexes; /* CREATE INDEX items */
List *triggers; /* CREATE TRIGGER items */
List *grants; /* GRANT items */
+ List *variables; /* CREATE VARIABLE items */
} CreateSchemaStmtContext;
@@ -4102,6 +4103,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.indexes = NIL;
cxt.triggers = NIL;
cxt.grants = NIL;
+ cxt.variables = NIL;
/*
* Run through each schema element in the schema element list. Separate
@@ -4170,6 +4172,15 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.grants = lappend(cxt.grants, element);
break;
+ case T_CreateSessionVarStmt:
+ {
+ CreateSessionVarStmt *elp = (CreateSessionVarStmt *) element;
+
+ setSchemaName(cxt.schemaname, &elp->variable->schemaname);
+ cxt.variables = lappend(cxt.variables, element);
+ }
+ break;
+
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(element));
@@ -4183,6 +4194,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
result = list_concat(result, cxt.indexes);
result = list_concat(result, cxt.triggers);
result = list_concat(result, cxt.grants);
+ result = list_concat(result, cxt.variables);
return result;
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 25fe3d58016..99a51877d34 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -23,6 +23,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_inherits.h"
+#include "catalog/pg_variable.h"
#include "catalog/toasting.h"
#include "commands/alter.h"
#include "commands/async.h"
@@ -182,6 +183,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CreateRangeStmt:
case T_CreateRoleStmt:
case T_CreateSchemaStmt:
+ case T_CreateSessionVarStmt:
case T_CreateSeqStmt:
case T_CreateStatsStmt:
case T_CreateStmt:
@@ -1389,6 +1391,10 @@ ProcessUtilitySlow(ParseState *pstate,
}
break;
+ case T_CreateSessionVarStmt:
+ address = CreateVariable(pstate, (CreateSessionVarStmt *) parsetree);
+ break;
+
/*
* ************* object creation / destruction **************
*/
@@ -2341,6 +2347,9 @@ AlterObjectTypeCommandTag(ObjectType objtype)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_ALTER_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_ALTER_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
break;
@@ -2649,6 +2658,9 @@ CreateCommandTag(Node *parsetree)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_DROP_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_DROP_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
@@ -3225,6 +3237,10 @@ CreateCommandTag(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ tag = CMDTAG_CREATE_VARIABLE;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
@@ -3759,6 +3775,10 @@ GetCommandLogLevel(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ lev = LOGSTMT_DDL;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index 6a76550a5e2..377de0b7c6b 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -31,6 +31,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/proclang.h"
#include "commands/tablespace.h"
@@ -129,6 +130,8 @@ static AclMode convert_type_priv_string(text *priv_type_text);
static AclMode convert_parameter_priv_string(text *priv_text);
static AclMode convert_largeobject_priv_string(text *priv_text);
static AclMode convert_role_priv_string(text *priv_type_text);
+static Oid convert_session_variable_name(text *varname);
+static AclMode convert_session_variable_priv_string(text *priv_type_text);
static AclResult pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode);
static void RoleMembershipCacheCallback(Datum arg, int cacheid, uint32 hashvalue);
@@ -851,6 +854,10 @@ acldefault(ObjectType objtype, Oid ownerId)
world_default = ACL_NO_RIGHTS;
owner_default = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ world_default = ACL_NO_RIGHTS;
+ owner_default = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", (int) objtype);
world_default = ACL_NO_RIGHTS; /* keep compiler quiet */
@@ -948,6 +955,9 @@ acldefault_sql(PG_FUNCTION_ARGS)
case 'T':
objtype = OBJECT_TYPE;
break;
+ case 'V':
+ objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type abbreviation: %c", objtypec);
}
@@ -5016,6 +5026,217 @@ pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode)
return ACLCHECK_NO_PRIV;
}
+/*
+ * has_session_variable_privilege variants
+ * These are all named "has_session_variable_privilege" at the SQL level.
+ * They take various combinations of variable name, variable OID,
+ * user name, user OID, or implicit user = current_user.
+ *
+ * The result is a boolean value: true if user has the indicated
+ * privilege, false if not, or NULL if session variable doesn't
+ * exists.
+ */
+
+/*
+ * has_session_variable_privilege_name_name
+ * Check user privileges on a session variable given
+ * name username, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_name(PG_FUNCTION_ARGS)
+{
+ Name rolename = PG_GETARG_NAME(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*rolename));
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name
+ * Check user privileges on a session variable given
+ * text session variable and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_name(PG_FUNCTION_ARGS)
+{
+ text *varname = PG_GETARG_TEXT_PP(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name_id
+ * Check user privileges on a session variable given
+ * name usename, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_id(PG_FUNCTION_ARGS)
+{
+ Name username = PG_GETARG_NAME(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*username));
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id
+ * Check user privileges on a session variable given
+ * session variable oid, and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_id(PG_FUNCTION_ARGS)
+{
+ Oid varid = PG_GETARG_OID(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_name
+ * Check user privileges on a session variable given
+ * roleid, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_name(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_id
+ * Check user privileges on a session variable given
+ * roleid, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_id(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * Given a session variable name expressed as a string, look it up and return
+ * Oid
+ */
+static Oid
+convert_session_variable_name(text *varname)
+{
+ return LookupVariableFromNameList(textToQualifiedNameList(varname), true);
+}
+
+/*
+ * convert_variable_priv_string
+ * Convert text string to AclMode value.
+ */
+static AclMode
+convert_session_variable_priv_string(text *priv_type_text)
+{
+ static const priv_map session_variable_priv_map[] = {
+ {"SELECT", ACL_SELECT},
+ {"SELECT WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_SELECT)},
+ {"UPDATE", ACL_UPDATE},
+ {"UPDATE WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_UPDATE)},
+ {NULL, 0}
+ };
+
+ return convert_any_priv_string(priv_type_text, session_variable_priv_map);
+}
/*
* initialization function (called by InitPostgres)
diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index bcfa5cb4add..f19b8bd4dc9 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -39,6 +39,7 @@
#include "catalog/pg_subscription.h"
#include "catalog/pg_transform.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "utils/array.h"
@@ -3741,3 +3742,115 @@ get_subscription_name(Oid subid, bool missing_ok)
return subname;
}
+
+/* ---------- PG_VARIABLE CACHE ---------- */
+
+/*
+ * get_varname_varid
+ * Given name and namespace of variable, look up the OID.
+ */
+Oid
+get_varname_varid(const char *varname, Oid varnamespace)
+{
+ return GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(varnamespace));
+}
+
+/*
+ * get_session_variable_name
+ * Returns a palloc'd copy of the name of a given session variable.
+ */
+char *
+get_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = pstrdup(NameStr(varform->varname));
+
+ ReleaseSysCache(tup);
+
+ return varname;
+}
+
+/*
+ * get_session_variable_namespace
+ * Returns the pg_namespace OID associated with a given session variable.
+ */
+Oid
+get_session_variable_namespace(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varnamespace = varform->varnamespace;
+
+ ReleaseSysCache(tup);
+
+ return varnamespace;
+}
+
+/*
+ * Returns the type of the given session variable.
+ */
+Oid
+get_session_variable_type(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid vartype;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ vartype = varform->vartype;
+
+ ReleaseSysCache(tup);
+
+ return vartype;
+}
+
+/*
+ * Returns the type, typmod and collid of the given session variable.
+ */
+void
+get_session_variable_type_typmod_collid(Oid varid, Oid *typid, int32 *typmod,
+ Oid *collid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ *typid = varform->vartype;
+ *typmod = varform->vartypmod;
+ *collid = varform->varcollation;
+
+ ReleaseSysCache(tup);
+}
diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c
index 56b6c368acf..ba6b19dc9af 100644
--- a/src/bin/pg_dump/common.c
+++ b/src/bin/pg_dump/common.c
@@ -246,6 +246,9 @@ getSchemaData(Archive *fout, int *numTablesPtr)
pg_log_info("reading subscription membership of tables");
getSubscriptionTables(fout);
+ pg_log_info("reading variables");
+ getVariables(fout);
+
free(inhinfo); /* not needed any longer */
*numTablesPtr = numTables;
diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index 5ae77f76367..5161ee780ea 100644
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -511,6 +511,12 @@ do { \
CONVERT_PRIV('r', "SELECT");
CONVERT_PRIV('w', "UPDATE");
}
+ else if (strcmp(type, "VARIABLE") == 0 ||
+ strcmp(type, "VARIABLES") == 0)
+ {
+ CONVERT_PRIV('r', "SELECT");
+ CONVERT_PRIV('w', "UPDATE");
+ }
else
abort();
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index 350cf659c41..d62260c255c 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -132,12 +132,14 @@ typedef struct _restoreOptions
int selFunction;
int selTrigger;
int selTable;
+ int selVariable;
SimpleStringList indexNames;
SimpleStringList functionNames;
SimpleStringList schemaNames;
SimpleStringList schemaExcludeNames;
SimpleStringList triggerNames;
SimpleStringList tableNames;
+ SimpleStringList variableNames;
int useDB;
ConnParams cparams; /* parameters to use if useDB */
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 632077113a4..1f6b56fd765 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -3129,6 +3129,14 @@ _tocEntryRequired(TocEntry *te, teSection curSection, ArchiveHandle *AH)
!simple_string_list_member(&ropt->triggerNames, te->tag))
return 0;
}
+ else if (strcmp(te->desc, "VARIABLE") == 0)
+ {
+ if (!ropt->selVariable)
+ return 0;
+ if (ropt->variableNames.head != NULL &&
+ !simple_string_list_member(&ropt->variableNames, te->tag))
+ return 0;
+ }
else
return 0;
}
@@ -3679,6 +3687,7 @@ _getObjectDescription(PQExpBuffer buf, const TocEntry *te)
strcmp(type, "TEXT SEARCH DICTIONARY") == 0 ||
strcmp(type, "TEXT SEARCH CONFIGURATION") == 0 ||
strcmp(type, "TYPE") == 0 ||
+ strcmp(type, "VARIABLE") == 0 ||
strcmp(type, "VIEW") == 0 ||
/* non-schema-specified objects */
strcmp(type, "DATABASE") == 0 ||
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index afd79287177..8631ba6b68c 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -364,6 +364,7 @@ static void dumpPublication(Archive *fout, const PublicationInfo *pubinfo);
static void dumpPublicationTable(Archive *fout, const PublicationRelInfo *pubrinfo);
static void dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo);
static void dumpSubscriptionTable(Archive *fout, const SubRelInfo *subrinfo);
+static void dumpVariable(Archive *fout, const VariableInfo *varinfo);
static void dumpDatabase(Archive *fout);
static void dumpDatabaseConfig(Archive *AH, PQExpBuffer outbuf,
const char *dbname, Oid dboid);
@@ -5450,6 +5451,188 @@ get_next_possible_free_pg_type_oid(Archive *fout, PQExpBuffer upgrade_query)
return next_possible_free_oid;
}
+/*
+ * getVariables
+ * get information about variables
+ */
+void
+getVariables(Archive *fout)
+{
+ PQExpBuffer query;
+ PGresult *res;
+ VariableInfo *varinfo;
+ int i_tableoid;
+ int i_oid;
+ int i_varname;
+ int i_varnamespace;
+ int i_vartype;
+ int i_vartypname;
+ int i_varowner;
+ int i_varcollation;
+ int i_varacl;
+ int i_acldefault;
+ int i,
+ ntups;
+
+ if (fout->remoteVersion < 180000)
+ return;
+
+ query = createPQExpBuffer();
+
+ /* get the variables in current database */
+ appendPQExpBuffer(query,
+ "SELECT v.tableoid, v.oid, v.varname,\n"
+ " v.varnamespace, v.vartype,\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n"
+ " CASE WHEN v.varcollation <> t.typcollation "
+ " THEN v.varcollation\n"
+ " ELSE 0\n"
+ " END AS varcollation,\n"
+ " v.varowner, v.varacl,\n"
+ " acldefault('V', v.varowner) AS acldefault\n"
+ "FROM pg_catalog.pg_variable v\n"
+ "JOIN pg_catalog.pg_type t "
+ "ON (v.vartype = t.oid)");
+
+ res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK);
+
+ ntups = PQntuples(res);
+
+ i_tableoid = PQfnumber(res, "tableoid");
+ i_oid = PQfnumber(res, "oid");
+ i_varname = PQfnumber(res, "varname");
+ i_varnamespace = PQfnumber(res, "varnamespace");
+ i_vartype = PQfnumber(res, "vartype");
+ i_vartypname = PQfnumber(res, "vartypname");
+ i_varcollation = PQfnumber(res, "varcollation");
+
+ i_varowner = PQfnumber(res, "varowner");
+ i_varacl = PQfnumber(res, "varacl");
+ i_acldefault = PQfnumber(res, "acldefault");
+
+ varinfo = pg_malloc(ntups * sizeof(VariableInfo));
+
+ for (i = 0; i < ntups; i++)
+ {
+ TypeInfo *vtype;
+
+ varinfo[i].dobj.objType = DO_VARIABLE;
+ varinfo[i].dobj.catId.tableoid =
+ atooid(PQgetvalue(res, i, i_tableoid));
+ varinfo[i].dobj.catId.oid = atooid(PQgetvalue(res, i, i_oid));
+ AssignDumpId(&varinfo[i].dobj);
+ varinfo[i].dobj.name = pg_strdup(PQgetvalue(res, i, i_varname));
+ varinfo[i].dobj.namespace =
+ findNamespace(atooid(PQgetvalue(res, i, i_varnamespace)));
+
+ varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype));
+ varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname));
+ varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
+
+ varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
+ varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
+ varinfo[i].dacl.privtype = 0;
+ varinfo[i].dacl.initprivs = NULL;
+ varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner));
+
+ /* do not try to dump ACL if no ACL exists */
+ if (!PQgetisnull(res, i, i_varacl))
+ varinfo[i].dobj.components |= DUMP_COMPONENT_ACL;
+
+ if (strlen(varinfo[i].rolname) == 0)
+ pg_log_warning("owner of variable \"%s\" appears to be invalid",
+ varinfo[i].dobj.name);
+
+ /* decide whether we want to dump it */
+ selectDumpableObject(&(varinfo[i].dobj), fout);
+
+ vtype = findTypeByOid(varinfo[i].vartype);
+ addObjectDependency(&varinfo[i].dobj, vtype->dobj.dumpId);
+ }
+ PQclear(res);
+
+ destroyPQExpBuffer(query);
+}
+
+/*
+ * dumpVariable
+ * dump the definition of the given session variable
+ */
+static void
+dumpVariable(Archive *fout, const VariableInfo *varinfo)
+{
+ DumpOptions *dopt = fout->dopt;
+
+ PQExpBuffer delq;
+ PQExpBuffer query;
+ char *qualvarname;
+ const char *vartypname;
+ Oid varcollation;
+
+ /* skip if not to be dumped */
+ if (!varinfo->dobj.dump || !dopt->dumpSchema)
+ return;
+
+ delq = createPQExpBuffer();
+ query = createPQExpBuffer();
+
+ qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
+ vartypname = varinfo->vartypname;
+ varcollation = varinfo->varcollation;
+
+ appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
+ qualvarname);
+
+ appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s",
+ qualvarname, vartypname);
+
+ if (OidIsValid(varcollation))
+ {
+ CollInfo *coll;
+
+ coll = findCollationByOid(varcollation);
+ if (coll)
+ appendPQExpBuffer(query, " COLLATE %s",
+ fmtQualifiedDumpable(coll));
+ }
+
+ appendPQExpBuffer(query, ";\n");
+
+ if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
+ ArchiveEntry(fout, varinfo->dobj.catId, varinfo->dobj.dumpId,
+ ARCHIVE_OPTS(.tag = varinfo->dobj.name,
+ .namespace = varinfo->dobj.namespace->dobj.name,
+ .owner = varinfo->rolname,
+ .description = "VARIABLE",
+ .section = SECTION_PRE_DATA,
+ .createStmt = query->data,
+ .dropStmt = delq->data));
+
+ /* dump comment if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_COMMENT)
+ dumpComment(fout, "VARIABLE", qualvarname,
+ NULL, varinfo->rolname,
+ varinfo->dobj.catId, 0, varinfo->dobj.dumpId);
+
+ /* dump ACL if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_ACL)
+ {
+ char *qvarname = pg_strdup(fmtId(varinfo->dobj.name));
+
+ dumpACL(fout, varinfo->dobj.dumpId, InvalidDumpId, "VARIABLE",
+ qvarname, NULL,
+ varinfo->dobj.namespace->dobj.name, NULL, varinfo->rolname,
+ &varinfo->dacl);
+
+ free(qvarname);
+ }
+
+ destroyPQExpBuffer(delq);
+ destroyPQExpBuffer(query);
+
+ free(qualvarname);
+}
+
static void
binary_upgrade_set_type_oids_by_type_oid(Archive *fout,
PQExpBuffer upgrade_buffer,
@@ -11124,6 +11307,9 @@ dumpDumpableObject(Archive *fout, DumpableObject *dobj)
case DO_REL_STATS:
dumpRelationStats(fout, (const RelStatsInfo *) dobj);
break;
+ case DO_VARIABLE:
+ dumpVariable(fout, (VariableInfo *) dobj);
+ break;
case DO_PRE_DATA_BOUNDARY:
case DO_POST_DATA_BOUNDARY:
/* never dumped, nothing to do */
@@ -15575,6 +15761,9 @@ dumpDefaultACL(Archive *fout, const DefaultACLInfo *daclinfo)
case DEFACLOBJ_NAMESPACE:
type = "SCHEMAS";
break;
+ case DEFACLOBJ_VARIABLE:
+ type = "VARIABLES";
+ break;
default:
/* shouldn't get here */
pg_fatal("unrecognized object type in default privileges: %d",
@@ -19297,6 +19486,7 @@ addBoundaryDependencies(DumpableObject **dobjs, int numObjs,
case DO_CONVERSION:
case DO_TABLE:
case DO_TABLE_ATTACH:
+ case DO_VARIABLE:
case DO_ATTRDEF:
case DO_PROCLANG:
case DO_CAST:
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index f08f5905aa3..cc27357478f 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -53,6 +53,7 @@ typedef enum
DO_TABLE,
DO_TABLE_ATTACH,
DO_ATTRDEF,
+ DO_VARIABLE,
DO_INDEX,
DO_INDEX_ATTACH,
DO_STATSEXT,
@@ -720,6 +721,19 @@ typedef struct _SubRelInfo
char *srsublsn;
} SubRelInfo;
+/*
+ * The VariableInfo struct is used to represent session variables
+ */
+typedef struct _VariableInfo
+{
+ DumpableObject dobj;
+ DumpableAcl dacl;
+ Oid vartype;
+ char *vartypname;
+ Oid varcollation;
+ const char *rolname; /* name of owner, or empty string */
+} VariableInfo;
+
/*
* common utility functions
*/
@@ -803,5 +817,6 @@ extern void getPublicationTables(Archive *fout, TableInfo tblinfo[],
int numTables);
extern void getSubscriptions(Archive *fout);
extern void getSubscriptionTables(Archive *fout);
+extern void getVariables(Archive *fout);
#endif /* PG_DUMP_H */
diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c
index f75e9928bad..b4c2d07a02e 100644
--- a/src/bin/pg_dump/pg_dump_sort.c
+++ b/src/bin/pg_dump/pg_dump_sort.c
@@ -77,6 +77,7 @@ enum dbObjectTypePriorities
PRIO_DUMMY_TYPE,
PRIO_ATTRDEF,
PRIO_LARGE_OBJECT,
+ PRIO_VARIABLE,
PRIO_PRE_DATA_BOUNDARY, /* boundary! */
PRIO_TABLE_DATA,
PRIO_SEQUENCE_SET,
@@ -119,6 +120,7 @@ static const int dbObjectTypePriority[] =
[DO_TABLE] = PRIO_TABLE,
[DO_TABLE_ATTACH] = PRIO_TABLE_ATTACH,
[DO_ATTRDEF] = PRIO_ATTRDEF,
+ [DO_VARIABLE] = PRIO_VARIABLE,
[DO_INDEX] = PRIO_INDEX,
[DO_INDEX_ATTACH] = PRIO_INDEX_ATTACH,
[DO_STATSEXT] = PRIO_STATSEXT,
@@ -1533,6 +1535,11 @@ describeDumpableObject(DumpableObject *obj, char *buf, int bufsize)
"RELATION STATISTICS FOR %s (ID %d OID %u)",
obj->name, obj->dumpId, obj->catId.oid);
return;
+ case DO_VARIABLE:
+ snprintf(buf, bufsize,
+ "VARIABLE %s (ID %d OID %u)",
+ obj->name, obj->dumpId, obj->catId.oid);
+ return;
}
/* shouldn't get here */
snprintf(buf, bufsize,
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 3945e4f0e2a..a5086e1becd 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -883,6 +883,16 @@ my %tests = (
unlike => { no_privs => 1, },
},
+ 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC'
+ => {
+ create_order => 56,
+ create_sql => 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;',
+ regexp => qr/^
+ \QALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;\E/xm,
+ like => { %full_runs, section_post_data => 1, },
+ unlike => { no_privs => 1, },
+ },
+
'ALTER ROLE regress_dump_test_role' => {
regexp => qr/^
\QALTER ROLE regress_dump_test_role WITH \E
@@ -1773,6 +1783,23 @@ my %tests = (
},
},
+ 'COMMENT ON VARIABLE dump_test.variable1' => {
+ create_order => 71,
+ create_sql => 'COMMENT ON VARIABLE dump_test.variable1
+ IS \'comment on variable\';',
+ regexp =>
+ qr/^\QCOMMENT ON VARIABLE dump_test.variable1 IS 'comment on variable';\E/m,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'COPY test_table' => {
create_order => 4,
create_sql => 'INSERT INTO dump_test.test_table (col1) '
@@ -4066,6 +4093,24 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable1 AS integer;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable1 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
@@ -4529,6 +4574,25 @@ my %tests = (
like => {},
},
+ 'GRANT SELECT ON VARIABLE dump_test.variable1' => {
+ create_order => 73,
+ create_sql =>
+ 'GRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;',
+ regexp => qr/^
+ \QGRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;\E
+ /xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ no_privs => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'REFRESH MATERIALIZED VIEW matview' => {
regexp => qr/^\QREFRESH MATERIALIZED VIEW dump_test.matview;\E/m,
like =>
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 26dfdde195a..6b870e2fc60 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -1097,6 +1097,9 @@ exec_command_d(PsqlScanState scan_state, bool active_branch, const char *cmd)
break;
}
break;
+ case 'V': /* Variables */
+ success = listVariables(pattern, show_verbose);
+ break;
case 'x': /* Extensions */
if (show_verbose)
success = listExtensionContents(pattern);
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..783cbb9cd11 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -1222,7 +1222,7 @@ listDefaultACLs(const char *pattern)
printfPQExpBuffer(&buf,
"SELECT pg_catalog.pg_get_userbyid(d.defaclrole) AS \"%s\",\n"
" n.nspname AS \"%s\",\n"
- " CASE d.defaclobjtype WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
+ " CASE d.defaclobjtype WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
" ",
gettext_noop("Owner"),
gettext_noop("Schema"),
@@ -1236,6 +1236,8 @@ listDefaultACLs(const char *pattern)
gettext_noop("type"),
DEFACLOBJ_NAMESPACE,
gettext_noop("schema"),
+ DEFACLOBJ_VARIABLE,
+ gettext_noop("session variable"),
gettext_noop("Type"));
printACLColumn(&buf, "d.defaclacl");
@@ -5318,6 +5320,102 @@ error_return:
return false;
}
+/*
+ * \dV
+ *
+ * listVariables()
+ */
+bool
+listVariables(const char *pattern, bool verbose)
+{
+ PQExpBufferData buf;
+ PGresult *res;
+ printQueryOpt myopt = pset.popt;
+ static const bool translate_columns[] = {false, false, false, false, false, false, false};
+
+ if (pset.sversion < 180000)
+ {
+ char sverbuf[32];
+
+ pg_log_error("The server (version %s) does not support session variables.",
+ formatPGVersionNumber(pset.sversion, false,
+ sverbuf, sizeof(sverbuf)));
+ return true;
+ }
+
+ initPQExpBuffer(&buf);
+
+ printfPQExpBuffer(&buf,
+ "SELECT n.nspname as \"%s\",\n"
+ " v.varname as \"%s\",\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n"
+ " (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
+ " WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
+ " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n",
+ gettext_noop("Schema"),
+ gettext_noop("Name"),
+ gettext_noop("Type"),
+ gettext_noop("Collation"),
+ gettext_noop("Owner"));
+
+ if (verbose)
+ {
+ appendPQExpBufferStr(&buf, ",\n ");
+ printACLColumn(&buf, "v.varacl");
+ appendPQExpBuffer(&buf,
+ ",\n pg_catalog.obj_description(v.oid, 'pg_variable') AS \"%s\"",
+ gettext_noop("Description"));
+ }
+
+ appendPQExpBufferStr(&buf,
+ "\nFROM pg_catalog.pg_variable v"
+ "\n LEFT JOIN pg_catalog.pg_namespace n ON n.oid = v.varnamespace");
+
+ appendPQExpBufferStr(&buf, "\nWHERE true\n");
+ if (!pattern)
+ appendPQExpBufferStr(&buf, " AND n.nspname <> 'pg_catalog'\n"
+ " AND n.nspname <> 'information_schema'\n");
+
+ if (!validateSQLNamePattern(&buf, pattern, true, false,
+ "n.nspname", "v.varname", NULL,
+ "pg_catalog.pg_variable_is_visible(v.oid)",
+ NULL, 3))
+ return false;
+
+ appendPQExpBufferStr(&buf, "ORDER BY 1,2;");
+
+ res = PSQLexec(buf.data);
+ termPQExpBuffer(&buf);
+ if (!res)
+ return false;
+
+ /*
+ * Most functions in this file are content to print an empty table when
+ * there are no matching objects. We intentionally deviate from that
+ * here, but only in !quiet mode, for historical reasons.
+ */
+ if (PQntuples(res) == 0 && !pset.quiet)
+ {
+ if (pattern)
+ pg_log_error("Did not find any session variable named \"%s\".",
+ pattern);
+ else
+ pg_log_error("Did not find any session variables.");
+ }
+ else
+ {
+ myopt.nullPrint = NULL;
+ myopt.title = _("List of variables");
+ myopt.translate_header = true;
+ myopt.translate_columns = translate_columns;
+ myopt.n_translate_columns = lengthof(translate_columns);
+
+ printQuery(res, &myopt, pset.queryFout, false, pset.logfile);
+ }
+
+ PQclear(res);
+ return true;
+}
/*
* \dFp
diff --git a/src/bin/psql/describe.h b/src/bin/psql/describe.h
index 18ecaa60949..55ced4aab7b 100644
--- a/src/bin/psql/describe.h
+++ b/src/bin/psql/describe.h
@@ -149,4 +149,7 @@ extern bool listOpFamilyFunctions(const char *access_method_pattern,
/* \dl or \lo_list */
extern bool listLargeObjects(bool verbose);
+/* \dV */
+extern bool listVariables(const char *pattern, bool varbose);
+
#endif /* DESCRIBE_H */
diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index da8e1ade5df..9a02a0986d4 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -266,6 +266,7 @@ slashUsage(unsigned short int pager)
HELP0(" \\dT[Sx+] [PATTERN] list data types\n");
HELP0(" \\du[Sx+] [PATTERN] list roles\n");
HELP0(" \\dv[Sx+] [PATTERN] list views\n");
+ HELP0(" \\dV[x+] [PATTERN] list session variables\n");
HELP0(" \\dx[x+] [PATTERN] list extensions\n");
HELP0(" \\dX[x] [PATTERN] list extended statistics\n");
HELP0(" \\dy[x+] [PATTERN] list event triggers\n");
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index eb8bc128720..c6a65bf7fad 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -970,6 +970,13 @@ static const SchemaQuery Query_for_trigger_of_table = {
.refnamespace = "c1.relnamespace",
};
+static const SchemaQuery Query_for_list_of_variables = {
+ .min_server_version = 180000,
+ .catname = "pg_catalog.pg_variable v",
+ .viscondition = "pg_catalog.pg_variable_is_visible(v.oid)",
+ .namespace = "v.varnamespace",
+ .result = "v.varname",
+};
/*
* Queries to get lists of names of various kinds of things, possibly
@@ -1318,6 +1325,7 @@ static const pgsql_thing_t words_after_create[] = {
* TABLE ... */
{"USER", Query_for_list_of_roles, NULL, NULL, Keywords_for_user_thing},
{"USER MAPPING FOR", NULL, NULL, NULL},
+ {"VARIABLE", NULL, NULL, &Query_for_list_of_variables},
{"VIEW", NULL, NULL, &Query_for_list_of_views},
{NULL} /* end of list */
};
@@ -1883,7 +1891,7 @@ psql_completion(const char *text, int start, int end)
"\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL",
"\\dm", "\\dn", "\\do", "\\dO", "\\dp", "\\dP", "\\dPi", "\\dPt",
"\\drds", "\\drg", "\\dRs", "\\dRp", "\\ds",
- "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy",
+ "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy", "\\dV",
"\\echo", "\\edit", "\\ef", "\\elif", "\\else", "\\encoding",
"\\endif", "\\errverbose", "\\ev",
"\\f",
@@ -2585,6 +2593,9 @@ match_previous_words(int pattern_id,
"ALL");
else if (Matches("ALTER", "SYSTEM", "SET", MatchAny))
COMPLETE_WITH("TO");
+ /* ALTER VARIABLE <name> */
+ else if (Matches("ALTER", "VARIABLE", MatchAny))
+ COMPLETE_WITH("OWNER TO", "RENAME TO", "SET SCHEMA");
/* ALTER VIEW <name> */
else if (Matches("ALTER", "VIEW", MatchAny))
COMPLETE_WITH("ALTER COLUMN", "OWNER TO", "RENAME", "RESET", "SET");
@@ -3165,7 +3176,7 @@ match_previous_words(int pattern_id,
"ROUTINE", "RULE", "SCHEMA", "SEQUENCE", "SERVER",
"STATISTICS", "SUBSCRIPTION", "TABLE",
"TABLESPACE", "TEXT SEARCH", "TRANSFORM FOR",
- "TRIGGER", "TYPE", "VIEW");
+ "TRIGGER", "TYPE", "VARIABLE", "VIEW");
else if (Matches("COMMENT", "ON", "ACCESS", "METHOD"))
COMPLETE_WITH_QUERY(Query_for_list_of_access_methods);
else if (Matches("COMMENT", "ON", "CONSTRAINT"))
@@ -3975,6 +3986,13 @@ match_previous_words(int pattern_id,
else if (TailMatches("=", MatchAnyExcept("*)")))
COMPLETE_WITH(",", ")");
}
+/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
+ /* Complete CREATE VARIABLE <name> with AS */
+ else if (TailMatches("CREATE", "VARIABLE", MatchAny))
+ COMPLETE_WITH("AS");
+ else if (TailMatches("VARIABLE", MatchAny, "AS"))
+ /* Complete CREATE VARIABLE <name> with AS types */
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
/* CREATE VIEW --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE [ OR REPLACE ] VIEW <name> with AS or WITH */
@@ -4252,6 +4270,12 @@ match_previous_words(int pattern_id,
else if (Matches("DROP", "TRANSFORM", "FOR", MatchAny, "LANGUAGE", MatchAny))
COMPLETE_WITH("CASCADE", "RESTRICT");
+ /* DROP VARIABLE */
+ else if (Matches("DROP", "VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ else if (Matches("DROP", "VARIABLE", MatchAny))
+ COMPLETE_WITH("CASCADE", "RESTRICT");
+
/* EXECUTE */
else if (Matches("EXECUTE"))
COMPLETE_WITH_QUERY(Query_for_list_of_prepared_statements);
@@ -4453,7 +4477,7 @@ match_previous_words(int pattern_id,
* objects supported.
*/
if (HeadMatches("ALTER", "DEFAULT", "PRIVILEGES"))
- COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS");
+ COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS", "VARIABLES");
else
COMPLETE_WITH_SCHEMA_QUERY_PLUS(Query_for_list_of_grantables,
"ALL FUNCTIONS IN SCHEMA",
@@ -4461,6 +4485,7 @@ match_previous_words(int pattern_id,
"ALL ROUTINES IN SCHEMA",
"ALL SEQUENCES IN SCHEMA",
"ALL TABLES IN SCHEMA",
+ "ALL VARIABLES IN SCHEMA",
"DATABASE",
"DOMAIN",
"FOREIGN DATA WRAPPER",
@@ -4475,7 +4500,8 @@ match_previous_words(int pattern_id,
"SEQUENCE",
"TABLE",
"TABLESPACE",
- "TYPE");
+ "TYPE",
+ "VARIABLE");
}
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "ALL") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "ALL"))
@@ -4483,7 +4509,8 @@ match_previous_words(int pattern_id,
"PROCEDURES IN SCHEMA",
"ROUTINES IN SCHEMA",
"SEQUENCES IN SCHEMA",
- "TABLES IN SCHEMA");
+ "TABLES IN SCHEMA",
+ "VARIABLES IN SCHEMA");
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "FOREIGN") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "FOREIGN"))
COMPLETE_WITH("DATA WRAPPER", "SERVER");
@@ -4519,6 +4546,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_tablespaces);
else if (TailMatches("TYPE"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
+ else if (TailMatches("VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatches("GRANT", MatchAny, MatchAny, MatchAny))
COMPLETE_WITH("TO");
else
@@ -4821,7 +4850,7 @@ match_previous_words(int pattern_id,
/* PREPARE xx AS */
else if (Matches("PREPARE", MatchAny, "AS"))
- COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM");
+ COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM", "LET");
/*
* PREPARE TRANSACTION is missing on purpose. It's intended for transaction
@@ -5305,6 +5334,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_roles);
else if (TailMatchesCS("\\dv*"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_views);
+ else if (TailMatchesCS("\\dV*"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatchesCS("\\dx*"))
COMPLETE_WITH_QUERY(Query_for_list_of_extensions);
else if (TailMatchesCS("\\dX*"))
diff --git a/src/include/catalog/Makefile b/src/include/catalog/Makefile
index 2bbc7805fe3..f98760de635 100644
--- a/src/include/catalog/Makefile
+++ b/src/include/catalog/Makefile
@@ -81,7 +81,8 @@ CATALOG_HEADERS := \
pg_publication_namespace.h \
pg_publication_rel.h \
pg_subscription.h \
- pg_subscription_rel.h
+ pg_subscription_rel.h \
+ pg_variable.h
GENERATED_HEADERS := $(CATALOG_HEADERS:%.h=%_d.h)
diff --git a/src/include/catalog/meson.build b/src/include/catalog/meson.build
index ec1cf467f6f..81398efa7c9 100644
--- a/src/include/catalog/meson.build
+++ b/src/include/catalog/meson.build
@@ -69,6 +69,7 @@ catalog_headers = [
'pg_publication_rel.h',
'pg_subscription.h',
'pg_subscription_rel.h',
+ 'pg_variable.h',
]
# The .dat files we need can just be listed alphabetically.
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index 8c7ccc69a3c..bdac0c13bec 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -97,6 +97,8 @@ extern Oid TypenameGetTypid(const char *typname);
extern Oid TypenameGetTypidExtended(const char *typname, bool temp_ok);
extern bool TypeIsVisible(Oid typid);
+extern bool VariableIsVisible(Oid varid);
+
extern FuncCandidateList FuncnameGetCandidates(List *names,
int nargs, List *argnames,
bool expand_variadic,
@@ -169,6 +171,10 @@ extern SearchPathMatcher *GetSearchPathMatcher(MemoryContext context);
extern SearchPathMatcher *CopySearchPathMatcher(SearchPathMatcher *path);
extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
+extern List *NamesFromList(List *names);
+extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
+extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
extern Oid FindDefaultConversionProc(int32 for_encoding, int32 to_encoding);
diff --git a/src/include/catalog/pg_default_acl.h b/src/include/catalog/pg_default_acl.h
index 728024b1fa7..5f94424a684 100644
--- a/src/include/catalog/pg_default_acl.h
+++ b/src/include/catalog/pg_default_acl.h
@@ -68,6 +68,7 @@ MAKE_SYSCACHE(DEFACLROLENSPOBJ, pg_default_acl_role_nsp_obj_index, 8);
#define DEFACLOBJ_FUNCTION 'f' /* function */
#define DEFACLOBJ_TYPE 'T' /* type */
#define DEFACLOBJ_NAMESPACE 'n' /* namespace */
+#define DEFACLOBJ_VARIABLE 'V' /* variable */
#endif /* EXPOSE_TO_CLIENT_CODE */
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 9e803d610d7..162cd048965 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5404,6 +5404,26 @@
prorettype => 'bool', proargtypes => 'oid oid text',
prosrc => 'has_largeobject_privilege_id_id' },
+{ oid => '9613', descr => 'user privilege on session variable by username, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name text text',
+ prosrc => 'has_session_variable_privilege_name_name' },
+{ oid => '9614', descr => 'user privilege on session variable by username, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name oid text', prosrc => 'has_session_variable_privilege_name_id' },
+{ oid => '9615', descr => 'user privilege on session variable by user oid, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text text', prosrc => 'has_session_variable_privilege_id_name' },
+{ oid => '9616', descr => 'user privilege on session variable by user oid, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid oid text', prosrc => 'has_session_variable_privilege_id_id' },
+{ oid => '9617', descr => 'current user privilege on session variable by seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'text text', prosrc => 'has_session_variable_privilege_name' },
+{ oid => '9618', descr => 'current user privilege on session variable by seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text', prosrc => 'has_session_variable_privilege_id' },
+
{ oid => '3355', descr => 'I/O',
proname => 'pg_ndistinct_in', prorettype => 'pg_ndistinct',
proargtypes => 'cstring', prosrc => 'pg_ndistinct_in' },
@@ -6604,6 +6624,9 @@
proname => 'pg_collation_is_visible', procost => '10', provolatile => 's',
prorettype => 'bool', proargtypes => 'oid',
prosrc => 'pg_collation_is_visible' },
+{ oid => '9999', descr => 'is session variable visible in search path?',
+ proname => 'pg_variable_is_visible', procost => '10', provolatile => 's',
+ prorettype => 'bool', proargtypes => 'oid', prosrc => 'pg_variable_is_visible' },
{ oid => '2854', descr => 'get OID of current session\'s temp schema, if any',
proname => 'pg_my_temp_schema', provolatile => 's', proparallel => 'r',
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
new file mode 100644
index 00000000000..3d3c6eb24b5
--- /dev/null
+++ b/src/include/catalog/pg_variable.h
@@ -0,0 +1,81 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.h
+ * definition of session variables system catalog (pg_variables)
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/catalog/pg_variable.h
+ *
+ * NOTES
+ * The Catalog.pm module reads this file and derives schema
+ * information.
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_VARIABLE_H
+#define PG_VARIABLE_H
+
+#include "catalog/genbki.h"
+#include "catalog/objectaddress.h"
+#include "catalog/pg_variable_d.h"
+#include "utils/acl.h"
+
+/* ----------------
+ * pg_variable definition. cpp turns this into
+ * typedef struct FormData_pg_variable
+ * ----------------
+ */
+CATALOG(pg_variable,9222,VariableRelationId)
+{
+ Oid oid; /* oid */
+
+ /* OID of entry in pg_type for variable's type */
+ Oid vartype BKI_LOOKUP(pg_type);
+
+ /* variable name */
+ NameData varname;
+
+ /* OID of namespace containing variable class */
+ Oid varnamespace BKI_LOOKUP(pg_namespace);
+
+ /* variable owner */
+ Oid varowner BKI_LOOKUP(pg_authid);
+
+ /* typmod for variable's type */
+ int32 vartypmod BKI_DEFAULT(-1);
+
+ /* variable collation */
+ Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation);
+
+
+#ifdef CATALOG_VARLEN /* variable-length fields start here */
+
+ /* access permissions */
+ aclitem varacl[1] BKI_DEFAULT(_null_);
+
+#endif
+} FormData_pg_variable;
+
+/* ----------------
+ * Form_pg_variable corresponds to a pointer to a tuple with
+ * the format of the pg_variable relation.
+ * ----------------
+ */
+typedef FormData_pg_variable *Form_pg_variable;
+
+DECLARE_TOAST(pg_variable, 9223, 9224);
+
+DECLARE_UNIQUE_INDEX_PKEY(pg_variable_oid_index, 9225, VariableOidIndexId, pg_variable, btree(oid oid_ops));
+DECLARE_UNIQUE_INDEX(pg_variable_varname_nsp_index, 9226, VariableNameNspIndexId, pg_variable, btree(varname name_ops, varnamespace oid_ops));
+
+extern ObjectAddress CreateVariable(ParseState *pstate,
+ CreateSessionVarStmt *stmt);
+extern void DropVariableById(Oid varid);
+
+MAKE_SYSCACHE(VARIABLENAMENSP, pg_variable_varname_nsp_index, 8);
+MAKE_SYSCACHE(VARIABLEOID, pg_variable_oid_index, 8);
+
+#endif /* PG_VARIABLE_H */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 0b208f51bdd..9858034ccf6 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2360,6 +2360,7 @@ typedef enum ObjectType
OBJECT_TSTEMPLATE,
OBJECT_TYPE,
OBJECT_USER_MAPPING,
+ OBJECT_VARIABLE,
OBJECT_VIEW,
} ObjectType;
@@ -3506,6 +3507,21 @@ typedef struct AlterStatsStmt
bool missing_ok; /* skip error if statistics object is missing */
} AlterStatsStmt;
+
+/* ----------------------
+ * {Create|Alter} VARIABLE Statement
+ * ----------------------
+ */
+typedef struct CreateSessionVarStmt
+{
+ NodeTag type;
+ RangeVar *variable; /* the variable to create */
+ TypeName *typeName; /* the type of variable */
+ CollateClause *collClause;
+ bool if_not_exists; /* do nothing if it already exists */
+} CreateSessionVarStmt;
+
+
/* ----------------------
* Create Function Statement
* ----------------------
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 40cf090ce61..793ace526df 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -485,6 +485,8 @@ PG_KEYWORD("validator", VALIDATOR, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("value", VALUE_P, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("values", VALUES, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("varchar", VARCHAR, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variable", VARIABLE, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variables", VARIABLES, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("variadic", VARIADIC, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("varying", VARYING, UNRESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("verbose", VERBOSE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index d250a714d59..ea86954dded 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -68,6 +68,7 @@ PG_CMDTAG(CMDTAG_ALTER_TRANSFORM, "ALTER TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TRIGGER, "ALTER TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TYPE, "ALTER TYPE", true, true, false)
PG_CMDTAG(CMDTAG_ALTER_USER_MAPPING, "ALTER USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_ALTER_VARIABLE, "ALTER VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_VIEW, "ALTER VIEW", true, false, false)
PG_CMDTAG(CMDTAG_ANALYZE, "ANALYZE", false, false, false)
PG_CMDTAG(CMDTAG_BEGIN, "BEGIN", false, false, false)
@@ -123,6 +124,7 @@ PG_CMDTAG(CMDTAG_CREATE_TRANSFORM, "CREATE TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TRIGGER, "CREATE TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TYPE, "CREATE TYPE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_USER_MAPPING, "CREATE USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_CREATE_VARIABLE, "CREATE VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_VIEW, "CREATE VIEW", true, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE, "DEALLOCATE", false, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE_ALL, "DEALLOCATE ALL", false, false, false)
@@ -175,6 +177,7 @@ PG_CMDTAG(CMDTAG_DROP_TRANSFORM, "DROP TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TRIGGER, "DROP TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TYPE, "DROP TYPE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_USER_MAPPING, "DROP USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_DROP_VARIABLE, "DROP VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_VIEW, "DROP VIEW", true, false, false)
PG_CMDTAG(CMDTAG_EXECUTE, "EXECUTE", false, false, false)
PG_CMDTAG(CMDTAG_EXPLAIN, "EXPLAIN", false, false, false)
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index 01ae5b719fd..5e1a8a82e90 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -169,6 +169,7 @@ typedef struct ArrayType Acl;
#define ACL_ALL_RIGHTS_SCHEMA (ACL_USAGE|ACL_CREATE)
#define ACL_ALL_RIGHTS_TABLESPACE (ACL_CREATE)
#define ACL_ALL_RIGHTS_TYPE (ACL_USAGE)
+#define ACL_ALL_RIGHTS_VARIABLE (ACL_SELECT|ACL_UPDATE)
/* operation codes for pg_*_aclmask */
typedef enum
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 6fab7aa6009..9503b528647 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -135,6 +135,7 @@ extern char get_func_prokind(Oid funcid);
extern bool get_func_leakproof(Oid funcid);
extern RegProcedure get_func_support(Oid funcid);
extern Oid get_relname_relid(const char *relname, Oid relnamespace);
+extern Oid get_varname_varid(const char *varname, Oid varnamespace);
extern char *get_rel_name(Oid relid);
extern Oid get_rel_namespace(Oid relid);
extern Oid get_rel_type_id(Oid relid);
@@ -207,6 +208,14 @@ extern char *get_publication_name(Oid pubid, bool missing_ok);
extern Oid get_subscription_oid(const char *subname, bool missing_ok);
extern char *get_subscription_name(Oid subid, bool missing_ok);
+extern char *get_session_variable_name(Oid varid);
+extern Oid get_session_variable_namespace(Oid varid);
+extern Oid get_session_variable_type(Oid varid);
+extern void get_session_variable_type_typmod_collid(Oid varid,
+ Oid *typid,
+ int32 *typmod,
+ Oid *collid);
+
#define type_is_array(typid) (get_element_type(typid) != InvalidOid)
/* type_is_array_domain accepts both plain arrays and domains over arrays */
#define type_is_array_domain(typid) (get_base_element_type(typid) != InvalidOid)
diff --git a/src/test/regress/expected/dependency.out b/src/test/regress/expected/dependency.out
index 75a078ada9e..cd8e4412fa9 100644
--- a/src/test/regress/expected/dependency.out
+++ b/src/test/regress/expected/dependency.out
@@ -151,3 +151,20 @@ owner of type deptest_t
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+-- should fail
+DROP DOMAIN vardomain;
+ERROR: cannot drop type vardomain because other objects depend on it
+DETAIL: column c of composite type vartype depends on type vardomain
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP TYPE vartype;
+ERROR: cannot drop type vartype because other objects depend on it
+DETAIL: session variable var1 depends on type vartype
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/expected/oidjoins.out b/src/test/regress/expected/oidjoins.out
index 215eb899be3..d9953321402 100644
--- a/src/test/regress/expected/oidjoins.out
+++ b/src/test/regress/expected/oidjoins.out
@@ -266,3 +266,7 @@ NOTICE: checking pg_subscription {subdbid} => pg_database {oid}
NOTICE: checking pg_subscription {subowner} => pg_authid {oid}
NOTICE: checking pg_subscription_rel {srsubid} => pg_subscription {oid}
NOTICE: checking pg_subscription_rel {srrelid} => pg_class {oid}
+NOTICE: checking pg_variable {vartype} => pg_type {oid}
+NOTICE: checking pg_variable {varnamespace} => pg_namespace {oid}
+NOTICE: checking pg_variable {varowner} => pg_authid {oid}
+NOTICE: checking pg_variable {varcollation} => pg_collation {oid}
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index f9db4032e1f..0c48fdfaf61 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6015,6 +6015,30 @@ COMMIT;
# final ON_ERROR_ROLLBACK: off
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | |
+(1 row)
+
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | =r/regress_variable_owner |
+(1 row)
+
+DROP VARIABLE var1;
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
-- check describing invalid multipart names
\dA regression.heap
improper qualified name (too many dotted names): regression.heap
@@ -6236,6 +6260,12 @@ cross-database references are not implemented: nonesuch.public.func_deps_stat
improper qualified name (too many dotted names): regression.myevt
\dy nonesuch.myevt
improper qualified name (too many dotted names): nonesuch.myevt
+\dV host.regression.public.var
+improper qualified name (too many dotted names): host.regression.public.var
+\dV regression|mydb.public.var
+cross-database references are not implemented: regression|mydb.public.var
+\dV nonesuch.public.var
+cross-database references are not implemented: nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
List of access methods
@@ -6470,6 +6500,12 @@ List of schemas
------+-------+-------+---------+----------+------
(0 rows)
+\dV "no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
improper qualified name (too many dotted names): "no.such.schema"."no.such.access.method"
@@ -6639,6 +6675,12 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
List of tables
@@ -6772,6 +6814,12 @@ List of text search templates
--------+------+------------+-----------+--------------+-----
(0 rows)
+\dV regression."no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -6819,6 +6867,8 @@ cross-database references are not implemented: "no.such.database"."no.such.schem
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
+cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
CREATE ROLE regress_du_role1;
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
new file mode 100644
index 00000000000..c36660ce6d3
--- /dev/null
+++ b/src/test/regress/expected/session_variables.out
@@ -0,0 +1,433 @@
+CREATE ROLE regress_variable_owner;
+SET log_statement TO ddl;
+-- should be ok
+CREATE VARIABLE var1 AS int;
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+ERROR: session variable cannot be pseudo-type anyelement
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+NOTICE: session variable "var2" does not exist, skipping
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+NOTICE: session variable "var1" already exists, skipping
+-- should fail
+CREATE VARIABLE var1 AS int;
+ERROR: session variable "var1" already exists
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TABLE t1;
+ERROR: cannot drop table t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+ERROR: cannot alter table "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TABLE t1;
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TYPE t1;
+ERROR: cannot drop type t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+ERROR: cannot alter type "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TYPE t1;
+SET log_statement TO default;
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+CREATE VARIABLE var1 AS testvar_domain;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter domain "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS testvar_type;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter type "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+NOTICE: NORMAL: orig=t normal=f istemp=f type=session variable identity=public.var1 name={public,var1} args={}
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+ obj_description
+-----------------------
+ some variable comment
+(1 row)
+
+DROP VARIABLE var1;
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+ varname | descr | type | object_names | object_args | ident
+---------------+-----------------------------------------+------------------+--------------------------+-------------+--------------------------------------------------------------------
+ svartest_var1 | session variable vartest1.svartest_var1 | session variable | {vartest1,svartest_var1} | {} | ("session variable",vartest1,svartest_var1,vartest1.svartest_var1)
+ svartest_var1 | session variable vartest2.svartest_var1 | session variable | {vartest2,svartest_var1} | {} | ("session variable",vartest2,svartest_var1,vartest2.svartest_var1)
+(2 rows)
+
+DROP SCHEMA vartest1 CASCADE;
+NOTICE: drop cascades to session variable vartest1.svartest_var1
+DROP SCHEMA vartest2 CASCADE;
+NOTICE: drop cascades to session variable vartest2.svartest_var1
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE ROLE regress_variable_reader;
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+DROP VARIABLE public.varxx;
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE public.var1 AS int;
+SET search_path TO public;
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+SET ROLE TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+--
+-- end of function has_session_variable_privilege tests.
+--
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+DROP VARIABLE public.var1;
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+DROP ROLE regress_variable_owner;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index e63ee2cf2bb..7aad3ad5d23 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -111,7 +111,7 @@ test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath sqljson
# NB: temp.sql does a reconnect which transiently uses 2 connections,
# so keep this parallel group to at most 19 tests
# ----------
-test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml
+test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml session_variables
# ----------
# Another group of parallel tests
diff --git a/src/test/regress/sql/dependency.sql b/src/test/regress/sql/dependency.sql
index 8d74ed7122c..6c18b7f840a 100644
--- a/src/test/regress/sql/dependency.sql
+++ b/src/test/regress/sql/dependency.sql
@@ -114,3 +114,17 @@ DROP USER regress_dep_user2;
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+
+-- should fail
+DROP DOMAIN vardomain;
+DROP TYPE vartype;
+
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index c58308ce14f..29d8caa7bac 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -1636,6 +1636,19 @@ COMMIT;
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+DROP VARIABLE var1;
+
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
+
-- check describing invalid multipart names
\dA regression.heap
\dA nonesuch.heap
@@ -1747,6 +1760,9 @@ DROP FUNCTION psql_error;
\dX nonesuch.public.func_deps_stat
\dy regression.myevt
\dy nonesuch.myevt
+\dV host.regression.public.var
+\dV regression|mydb.public.var
+\dV nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
@@ -1788,6 +1804,8 @@ DROP FUNCTION psql_error;
\dx "no.such.installed.extension"
\dX "no.such.extended.statistics"
\dy "no.such.event.trigger"
+\dV "no.such.variable"
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
@@ -1828,6 +1846,7 @@ DROP FUNCTION psql_error;
\dx "no.such.schema"."no.such.installed.extension"
\dX "no.such.schema"."no.such.extended.statistics"
\dy "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
@@ -1852,6 +1871,7 @@ DROP FUNCTION psql_error;
\dP regression."no.such.schema"."no.such.partitioned.relation"
\dT regression."no.such.schema"."no.such.data.type"
\dX regression."no.such.schema"."no.such.extended.statistics"
+\dV regression."no.such.schema"."no.such.variable"
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -1877,6 +1897,7 @@ DROP FUNCTION psql_error;
\dP "no.such.database"."no.such.schema"."no.such.partitioned.relation"
\dT "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
new file mode 100644
index 00000000000..eeb0f94ca3c
--- /dev/null
+++ b/src/test/regress/sql/session_variables.sql
@@ -0,0 +1,297 @@
+CREATE ROLE regress_variable_owner;
+
+SET log_statement TO ddl;
+
+-- should be ok
+CREATE VARIABLE var1 AS int;
+
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+
+-- should fail
+CREATE VARIABLE var1 AS int;
+
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TABLE t1;
+
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TABLE t1;
+
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TYPE t1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+SET log_statement TO default;
+
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+
+CREATE VARIABLE var1 AS testvar_domain;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+CREATE VARIABLE var1 AS testvar_type;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+
+DROP VARIABLE var1;
+
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+
+DROP SCHEMA vartest1 CASCADE;
+DROP SCHEMA vartest2 CASCADE;
+
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+
+CREATE ROLE regress_variable_reader;
+
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+
+DROP VARIABLE public.varxx;
+
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE public.var1 AS int;
+
+SET search_path TO public;
+
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+
+SET ROLE TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+--
+-- end of function has_session_variable_privilege tests.
+--
+
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+
+DROP VARIABLE public.var1;
+
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+
+DROP ROLE regress_variable_owner;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index b09d8af7183..cfb92f8e6c8 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -544,6 +544,7 @@ CreateRoleStmt
CreateSchemaStmt
CreateSchemaStmtContext
CreateSeqStmt
+CreateSessionVarStmt
CreateStatsStmt
CreateStmt
CreateStmtContext
@@ -884,6 +885,7 @@ FormData_pg_ts_parser
FormData_pg_ts_template
FormData_pg_type
FormData_pg_user_mapping
+FormData_pg_variable
FormExtraData_pg_attribute
Form_pg_aggregate
Form_pg_am
@@ -943,6 +945,7 @@ Form_pg_ts_parser
Form_pg_ts_template
Form_pg_type
Form_pg_user_mapping
+Form_pg_variable
FormatNode
FreeBlockNumberArray
FreeListData
@@ -3117,6 +3120,7 @@ VarString
VarStringSortSupport
Variable
VariableAssignHook
+VariableInfo
VariableSetKind
VariableSetStmt
VariableShowStmt
--
2.48.1
[text/x-patch] v20250220-0002-Storage-for-session-variables-and-SQL-interface.patch (159.6K, ../../CAFj8pRC9WKvJm22wfPExiSfQkn4r7mbHntPk11Ohh-50Avw9Bg@mail.gmail.com/23-v20250220-0002-Storage-for-session-variables-and-SQL-interface.patch)
download | inline diff:
From f522b567a63c65e9e4ea85d7476a9f957ac968d6 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Thu, 6 Jul 2023 08:29:21 +0200
Subject: [PATCH 02/21] Storage for session variables and SQL interface
Session variables are stored in session memory in a dedicated hash table.
They are set by the LET command and read by the SELECT command.
The access rights should be checked.
The identifiers of session variables should always be shadowed by possible
column identifiers: we don't want to break an application by creating some
badly named session variable.
The limits of this patch (solved by other patches):
- session variables block parallel execution
- session variables blocks simple expression evaluation (in plpgsql)
- SQL functions with session variables are not inlined
- CALL statement is not supported (usage of direct access to express executor)
- EXECUTE statement is not supported (usage of direct access to express executor)
- memory used by dropped session variables is not released
Implementations of EXPLAIN LET and PREPARE LET statements
are in separate patches (for better readability)
---
doc/src/sgml/catalogs.sgml | 13 +
doc/src/sgml/ddl.sgml | 61 +
doc/src/sgml/func.sgml | 4 +-
doc/src/sgml/glossary.sgml | 5 +-
doc/src/sgml/parallel.sgml | 6 +
doc/src/sgml/plpgsql.sgml | 14 +
doc/src/sgml/ref/allfiles.sgml | 1 +
doc/src/sgml/ref/alter_variable.sgml | 1 +
doc/src/sgml/ref/create_variable.sgml | 5 +-
doc/src/sgml/ref/drop_variable.sgml | 1 +
doc/src/sgml/ref/let.sgml | 96 ++
doc/src/sgml/reference.sgml | 1 +
src/backend/catalog/dependency.c | 5 +
src/backend/catalog/namespace.c | 289 ++++
src/backend/catalog/pg_variable.c | 2 +
src/backend/commands/Makefile | 1 +
src/backend/commands/meson.build | 1 +
src/backend/commands/prepare.c | 10 +
src/backend/commands/session_variable.c | 529 +++++++
src/backend/executor/Makefile | 1 +
src/backend/executor/execExpr.c | 32 +
src/backend/executor/execMain.c | 66 +
src/backend/executor/meson.build | 1 +
src/backend/executor/svariableReceiver.c | 172 +++
src/backend/nodes/nodeFuncs.c | 10 +
src/backend/optimizer/plan/planner.c | 36 +
src/backend/optimizer/plan/setrefs.c | 156 ++-
src/backend/optimizer/prep/prepjointree.c | 3 +
src/backend/optimizer/util/clauses.c | 33 +-
src/backend/parser/analyze.c | 272 +++-
src/backend/parser/gram.y | 39 +-
src/backend/parser/parse_agg.c | 9 +
src/backend/parser/parse_expr.c | 223 ++-
src/backend/parser/parse_func.c | 2 +
src/backend/parser/parse_merge.c | 1 +
src/backend/tcop/dest.c | 7 +
src/backend/tcop/utility.c | 16 +
src/backend/utils/adt/ruleutils.c | 46 +
src/backend/utils/cache/plancache.c | 41 +-
src/backend/utils/fmgr/fmgr.c | 10 +-
src/bin/psql/tab-complete.in.c | 12 +-
src/include/catalog/namespace.h | 1 +
src/include/catalog/pg_variable.h | 9 +
src/include/commands/session_variable.h | 30 +
src/include/executor/svariableReceiver.h | 22 +
src/include/nodes/execnodes.h | 14 +
src/include/nodes/parsenodes.h | 17 +
src/include/nodes/pathnodes.h | 14 +
src/include/nodes/plannodes.h | 9 +
src/include/nodes/primnodes.h | 14 +
src/include/optimizer/planmain.h | 2 +
src/include/parser/kwlist.h | 1 +
src/include/parser/parse_node.h | 3 +
src/include/tcop/cmdtaglist.h | 1 +
src/include/tcop/dest.h | 1 +
src/pl/plpgsql/src/pl_exec.c | 3 +-
.../regress/expected/session_variables.out | 1232 +++++++++++++++++
src/test/regress/sql/session_variables.sql | 883 ++++++++++++
src/tools/pgindent/typedefs.list | 5 +
59 files changed, 4467 insertions(+), 27 deletions(-)
create mode 100644 doc/src/sgml/ref/let.sgml
create mode 100644 src/backend/commands/session_variable.c
create mode 100644 src/backend/executor/svariableReceiver.c
create mode 100644 src/include/commands/session_variable.h
create mode 100644 src/include/executor/svariableReceiver.h
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 7ba91b1f4b1..4f502274bfa 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9810,6 +9810,19 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcreate_lsn</structfield> <type>pg_lsn</type>
+ </para>
+ <para>
+ LSN of the transaction where the variable was created.
+ <structfield>varcreate_lsn</structfield> and
+ <structfield>oid</structfield> together form the all-time unique
+ identifier (<structfield>oid</structfield> alone is not enough, since
+ object identifiers can get reused).
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>varname</structfield> <type>name</type>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index edfb7db24fc..5e671d5be4d 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5384,6 +5384,67 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
The session variable holds value in session memory. This value is private
to each session and is released when the session ends.
</para>
+
+ <para>
+ The value of a session variable is set with the SQL statement
+ <command>LET</command>. The value of a session variable can be retrieved
+ with the SQL statement <command>SELECT</command>.
+<programlisting>
+CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
+</programlisting>
+
+ or
+
+<programlisting>
+CREATE VARIABLE public.current_user_id AS integer;
+GRANT SELECT ON VARIABLE public.current_user_id TO PUBLIC;
+LET current_user_id = (SELECT id FROM users WHERE usename = session_user);
+SELECT current_user_id;
+</programlisting>
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a variable's value returns a <literal>NULL</literal>, unless its value has
+ been set to something else in the current session using the
+ <command>LET</command> command. Session variables are not transactional:
+ any changes made to the value of a session variable in a transaction won't
+ be undone if the transaction is rolled back (just like variables in
+ procedural languages). Session variables themselves are persistent, but
+ their values are neither persistent nor shared (like the content of
+ temporary tables).
+ </para>
+
+ <para>
+ Inside a query or an expression, a session variable can be
+ <quote>shadowed</quote> by a column with the same name. Similarly, the
+ name of a function or procedure argument or a PL/pgSQL variable (see
+ <xref linkend="plpgsql-declarations"/>) can shadow a session variable
+ in the routine's body. Such collisions of identifiers can be resolved
+ by using qualified identifiers: Session variables can be qualified with
+ the schema name, columns can use table aliases, routine variables can use
+ block labels, and routine arguments can use the routine name.
+<programlisting>
+CREATE VARIABLE name AS text;
+LET name = 'John';
+
+CREATE TABLE foo(name text);
+INSERT INTO foo VALUES('Alice');
+
+-- variable name is shadowed
+SELECT name FROM foo;
+</programlisting>
+
+ which returns:
+
+<programlisting>
+ name
+-------
+ Alice
+</programlisting>
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index acba5962222..902098bc5e8 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25600,8 +25600,8 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
't' for <literal>TABLESPACE</literal>,
'F' for <literal>FOREIGN DATA WRAPPER</literal>,
'S' for <literal>FOREIGN SERVER</literal>,
- or
- 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal>.
+ 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal> or
+ 'V' for <literal>SESSION VARIABLE</literal>.
</para></entry>
</row>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index b921f5a3339..81988f2dfea 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1675,8 +1675,9 @@
<para>
A persistent database object that holds a value in session memory. This
value is private to each session and is released when the session ends.
- Read or write access to session variables is controlled by privileges,
- similar to other database objects.
+ The default value of the session variable is null. Read or write access
+ to session variables is controlled by privileges, similar to other database
+ objects.
</para>
<para>
For more information, see <xref linkend="ddl-session-variables"/>.
diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index 1ce9abf86f5..683dede6adc 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -515,6 +515,12 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
Plan nodes that reference a correlated <literal>SubPlan</literal>.
</para>
</listitem>
+
+ <listitem>
+ <para>
+ Plan nodes that use a session variable.
+ </para>
+ </listitem>
</itemizedlist>
<sect2 id="parallel-labeling">
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index 78e4983139b..bfbff9ab74e 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -6034,6 +6034,20 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE;
</programlisting>
</para>
</sect3>
+
+ <sect3 id="plpgsql-porting-package-variables">
+ <title><command>Packages and package variables</command></title>
+
+ <para>
+ The <application>PL/pgSQL</application> language has no packages, and
+ therefore no package variables or package constants.
+ You can consider translating an Oracle package into a schema in
+ <productname>PostgreSQL</productname>. Package functions and procedures
+ would then become functions and procedures in that schema, and package
+ variables could be translated to session variables in that schema.
+ (see <xref linkend="ddl-session-variables"/>).
+ </para>
+ </sect3>
</sect2>
<sect2 id="plpgsql-porting-appendix">
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index 2f67de3e21b..cc3bd5ab540 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -158,6 +158,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY grant SYSTEM "grant.sgml">
<!ENTITY importForeignSchema SYSTEM "import_foreign_schema.sgml">
<!ENTITY insert SYSTEM "insert.sgml">
+<!ENTITY let SYSTEM "let.sgml">
<!ENTITY listen SYSTEM "listen.sgml">
<!ENTITY load SYSTEM "load.sgml">
<!ENTITY lock SYSTEM "lock.sgml">
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
index 96d2586423e..221a699469b 100644
--- a/doc/src/sgml/ref/alter_variable.sgml
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -173,6 +173,7 @@ ALTER VARIABLE boo SET SCHEMA private;
<simplelist type="inline">
<member><xref linkend="sql-createvariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
</refentry>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index 6e988f2e472..cd9ff63975a 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -120,9 +120,11 @@ CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceab
<title>Examples</title>
<para>
- Create an date session variable <literal>var1</literal>:
+ Create a session variable <literal>var1</literal> of data type date:
<programlisting>
CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
</programlisting>
</para>
@@ -143,6 +145,7 @@ CREATE VARIABLE var1 AS date;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
index 5bdb3560f0b..67988b5fcd8 100644
--- a/doc/src/sgml/ref/drop_variable.sgml
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -111,6 +111,7 @@ DROP VARIABLE var1;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/let.sgml b/doc/src/sgml/ref/let.sgml
new file mode 100644
index 00000000000..00f9bea91fe
--- /dev/null
+++ b/doc/src/sgml/ref/let.sgml
@@ -0,0 +1,96 @@
+<!--
+doc/src/sgml/ref/let.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-let">
+ <indexterm zone="sql-let">
+ <primary>LET</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>changing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>LET</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>LET</refname>
+ <refpurpose>change a session variable's value</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+LET <replaceable class="parameter">session_variable</replaceable> = <replaceable class="parameter">sql_expression</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>LET</command> command assigns a value to the specified session
+ variable.
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">session_variable</replaceable></term>
+ <listitem>
+ <para>
+ The name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">sql_expression</replaceable></term>
+ <listitem>
+ <para>
+ An arbitrary SQL expression. The result must be of a data type that can
+ be cast to the type of the session variable in an assignment.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+<programlisting>
+CREATE VARIABLE myvar AS integer;
+LET myvar = 10;
+LET myvar = (SELECT sum(val) FROM tab);
+</programlisting>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>LET</command> is a <productname>PostgreSQL</productname>
+ extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index 25578f3946c..13e4adc5df3 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -186,6 +186,7 @@
&grant;
&importForeignSchema;
&insert;
+ &let;
&listen;
&load;
&lock;
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 9e0f648b74f..90c9e8bb254 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1864,6 +1864,11 @@ find_expr_references_walker(Node *node,
{
Param *param = (Param *) node;
+ /* a variable parameter depends on the session variable */
+ if (param->paramkind == PARAM_VARIABLE)
+ add_object_address(VariableRelationId, param->paramvarid, 0,
+ context->addrs);
+
/* A parameter must depend on the parameter's datatype */
add_object_address(TypeRelationId, param->paramtype, 0,
context->addrs);
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 4307cad15c7..beafee2a341 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -3497,6 +3497,295 @@ NamesFromList(List *names)
return result;
}
+/* -----
+ * IdentifyVariable - try to find a variable from a list of identifiers
+ *
+ * Returns the OID of the variable found, or InvalidOid.
+ *
+ * "names" is a list of up to four identifiers; possible meanings are:
+ * - variable (searched on the search_path)
+ * - schema.variable
+ * - variable.attribute (searched on the search_path)
+ * - schema.variable.attribute
+ * - database.schema.variable
+ * - database.schema.variable.attribute
+ *
+ * If there is more than one way to identify a variable, "not_unique" will be
+ * set to true.
+ *
+ * Unless "noerror" is true, an error is raised if there are more than four
+ * identifiers in the list, or if the named database is not the current one.
+ * This is useful if we want to identify a shadowed variable.
+ *
+ * If an attribute is identified, it is stored in "attrname", otherwise the
+ * parameter is set to NULL.
+ *
+ * The identified session variable will be locked with an AccessShareLock.
+ * -----
+ */
+Oid
+IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror)
+{
+ Oid varid = InvalidOid;
+ Oid old_varid = InvalidOid;
+ uint64 inval_count;
+ bool retry = false;
+
+ /*
+ * DDL operations can change the results of a name lookup. Since all such
+ * operations will generate invalidation messages, we keep track of
+ * whether any such messages show up while we're performing the operation,
+ * and retry until either (1) no more invalidation messages show up or (2)
+ * the answer doesn't change.
+ */
+ for (;;)
+ {
+ Node *field1 = NULL;
+ Node *field2 = NULL;
+ Node *field3 = NULL;
+ Node *field4 = NULL;
+ char *a = NULL;
+ char *b = NULL;
+ char *c = NULL;
+ char *d = NULL;
+ Oid varoid_without_attr = InvalidOid;
+ Oid varoid_with_attr = InvalidOid;
+
+ *not_unique = false;
+ *attrname = NULL;
+ varid = InvalidOid;
+
+ inval_count = SharedInvalidMessageCounter;
+
+ switch (list_length(names))
+ {
+ case 1:
+ field1 = linitial(names);
+
+ Assert(IsA(field1, String));
+
+ varid = LookupVariable(NULL, strVal(field1), true);
+ break;
+
+ case 2:
+ field1 = linitial(names);
+ field2 = lsecond(names);
+
+ Assert(IsA(field1, String));
+ a = strVal(field1);
+
+ if (IsA(field2, String))
+ {
+ /* when both fields are of string type */
+ b = strVal(field2);
+
+ /*
+ * a.b can mean "schema"."variable" or
+ * "variable"."attribute". Check both variants, and
+ * returns InvalidOid with not_unique flag, when both
+ * interpretations are possible.
+ */
+ varoid_without_attr = LookupVariable(a, b, true);
+ varoid_with_attr = LookupVariable(NULL, a, true);
+ }
+ else
+ {
+ /* the last field of list can be star too */
+ Assert(IsA(field2, A_Star));
+
+ /*
+ * The syntax ident.* is used only by relation aliases,
+ * and then this identifier cannot be a reference to
+ * session variable.
+ */
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = b;
+ varid = varoid_with_attr;
+ }
+ break;
+
+ case 3:
+ {
+ bool field1_is_catalog = false;
+
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+
+ if (IsA(field3, String))
+ {
+ c = strVal(field3);
+
+ /*
+ * a.b.c can mean catalog.schema.variable or
+ * schema.variable.attribute.
+ *
+ * Check both variants, and set not_unique flag, when
+ * both interpretations are possible.
+ *
+ * When third node is star, only possible
+ * interpretation is schema.variable.*, but this
+ * pattern is not supported now.
+ */
+ varoid_with_attr = LookupVariable(a, b, true);
+
+ /*
+ * check pattern catalog.schema.variable only when
+ * there is possibility to success.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) == 0)
+ {
+ field1_is_catalog = true;
+ varoid_without_attr = LookupVariable(b, c, true);
+ }
+ }
+ else
+ {
+ Assert(IsA(field3, A_Star));
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = c;
+ varid = varoid_with_attr;
+ }
+
+ /*
+ * When we didn't find variable, we can (when it is
+ * allowed) raise cross-database reference error.
+ */
+ if (!OidIsValid(varid) && !noerror && !field1_is_catalog)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+ break;
+
+ case 4:
+ {
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+ field4 = lfourth(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+ Assert(IsA(field3, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+ c = strVal(field3);
+
+ /*
+ * In this case, "a" is used as catalog name - check it.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) != 0)
+ {
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+
+ if (IsA(field4, String))
+ {
+ d = strVal(field4);
+ }
+ else
+ {
+ Assert(IsA(field4, A_Star));
+ return InvalidOid;
+ }
+
+ *attrname = d;
+ varid = LookupVariable(b, c, true);
+ }
+ break;
+
+ default:
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper qualified name (too many dotted names): %s",
+ NameListToString(names))));
+ return InvalidOid;
+ }
+
+ /*
+ * If, upon retry, we get back the same OID we did last time, then the
+ * invalidation messages we processed did not change the final answer.
+ * So we're done.
+ *
+ * If we got a different OID, we've locked the variable that used to
+ * have this name rather than the one that does now. So release the
+ * lock.
+ */
+ if (retry)
+ {
+ if (old_varid == varid)
+ break;
+
+ if (OidIsValid(old_varid))
+ UnlockDatabaseObject(VariableRelationId, old_varid, 0, AccessShareLock);
+ }
+
+ /*
+ * Lock the variable. This will also accept any pending invalidation
+ * messages. If we got back InvalidOid, indicating not found, then
+ * there's nothing to lock, but we accept invalidation messages
+ * anyway, to flush any negative catcache entries that may be
+ * lingering.
+ */
+ if (!OidIsValid(varid))
+ AcceptInvalidationMessages();
+ else
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ /*
+ * If no invalidation message were processed, we're done!
+ */
+ if (inval_count == SharedInvalidMessageCounter)
+ break;
+
+ retry = true;
+ old_varid = varid;
+ varid = InvalidOid;
+ }
+
+ return varid;
+}
+
/*
* DeconstructQualifiedName
* Given a possibly-qualified name expressed as a list of String nodes,
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 29d967a2d5b..bb445e9434b 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -26,6 +26,7 @@
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
+#include "utils/pg_lsn.h"
#include "utils/syscache.h"
static ObjectAddress create_variable(const char *varName,
@@ -101,6 +102,7 @@ create_variable(const char *varName,
varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varcreate_lsn - 1] = LSNGetDatum(GetXLogInsertRecPtr());
values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile
index 48f7348f91c..1cfaeca51ea 100644
--- a/src/backend/commands/Makefile
+++ b/src/backend/commands/Makefile
@@ -50,6 +50,7 @@ OBJS = \
schemacmds.o \
seclabel.o \
sequence.o \
+ session_variable.o \
statscmds.o \
subscriptioncmds.o \
tablecmds.o \
diff --git a/src/backend/commands/meson.build b/src/backend/commands/meson.build
index ef0d407a383..ce1619e3089 100644
--- a/src/backend/commands/meson.build
+++ b/src/backend/commands/meson.build
@@ -38,6 +38,7 @@ backend_sources += files(
'schemacmds.c',
'seclabel.c',
'sequence.c',
+ 'session_variable.c',
'statscmds.c',
'subscriptioncmds.c',
'tablecmds.c',
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index c025b1f9f8c..06875a7b411 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -339,6 +339,16 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
i++;
}
+ /*
+ * The arguments of EXECUTE are evaluated by a direct expression
+ * executor call. This mode doesn't support session variables yet.
+ * It will be enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
/* Prepare the expressions for execution */
exprstates = ExecPrepareExprList(params, estate);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
new file mode 100644
index 00000000000..d2891a1dcb7
--- /dev/null
+++ b/src/backend/commands/session_variable.c
@@ -0,0 +1,529 @@
+/*-------------------------------------------------------------------------
+ *
+ * session_variable.c
+ * session variable creation/manipulation commands
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/commands/session_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "rewrite/rewriteHandler.h"
+#include "storage/lmgr.h"
+#include "storage/proc.h"
+#include "tcop/tcopprot.h"
+#include "utils/builtins.h"
+#include "utils/datum.h"
+#include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/snapmgr.h"
+#include "utils/syscache.h"
+
+/*
+ * The values of session variables are stored in the backend's private memory
+ * in the dedicated memory context SVariableMemoryContext in binary format.
+ * They are stored in the "sessionvars" hash table, whose key is the OID of the
+ * variable. However, the OID is not good enough to identify a session
+ * variable: concurrent sessions could drop the session variable and create a
+ * new one, which could be assigned the same OID. To ensure that the values
+ * stored in memory and the catalog definition match, we also keep track of
+ * the "create_lsn". Before any access to the variable values, we need to
+ * check if the LSN stored in memory matches the LSN in the catalog. If there
+ * is a mismatch between the LSNs, or if the OID is not present in pg_variable
+ * at all, the value stored in memory is released.
+ */
+typedef struct SVariableData
+{
+ Oid varid; /* pg_variable OID of the variable (hash key) */
+ XLogRecPtr create_lsn;
+
+ bool isnull;
+ Datum value;
+
+ Oid typid;
+ int16 typlen;
+ bool typbyval;
+
+ bool is_domain;
+
+ /*
+ * domain_check_extra holds cached domain metadata. This "extra" is
+ * usually stored in fn_mcxt. We do not have access to that memory context
+ * for session variables, but we can use TopTransactionContext instead.
+ * A fresh value is forced when we detect we are in a different transaction
+ * (the local transaction ID differs from domain_check_extra_lxid).
+ */
+ void *domain_check_extra;
+ LocalTransactionId domain_check_extra_lxid;
+
+ /*
+ * Stored value and type description can be outdated when we receive a
+ * sinval message. We then have to check if the stored data are still
+ * trustworthy.
+ */
+ bool is_valid;
+
+ uint32 hashvalue; /* used for pairing sinval message */
+} SVariableData;
+
+typedef SVariableData *SVariable;
+
+static HTAB *sessionvars = NULL; /* hash table for session variables */
+
+static MemoryContext SVariableMemoryContext = NULL;
+
+/*
+ * Callback function for session variable invalidation.
+ */
+static void
+pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
+
+ Assert(sessionvars);
+
+ /*
+ * If the hashvalue is not specified, we have to recheck all currently
+ * used session variables. Since we can't tell the exact session variable
+ * from its hashvalue, we have to iterate over all items in the hash bucket.
+ */
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (hashvalue == 0 || svar->hashvalue == hashvalue)
+ {
+ svar->is_valid = false;
+ }
+ }
+}
+
+/*
+ * Release stored value, free memory
+ */
+static void
+free_session_variable_value(SVariable svar)
+{
+ /* clean the current value */
+ if (!svar->isnull)
+ {
+ if (!svar->typbyval)
+ pfree(DatumGetPointer(svar->value));
+
+ svar->isnull = true;
+ }
+
+ svar->value = (Datum) 0;
+}
+
+/*
+ * Returns true when the entry in pg_variable is consistent with the given
+ * session variable.
+ */
+static bool
+is_session_variable_valid(SVariable svar)
+{
+ HeapTuple tp;
+ bool result = false;
+
+ Assert(OidIsValid(svar->varid));
+
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ /*
+ * The OID alone is not enough as an unique identifier, because OID
+ * values get recycled, and a new session variable could have got
+ * the same OID. We do a second check against the 64-bit LSN when
+ * the variable was created.
+ */
+ if (svar->create_lsn == ((Form_pg_variable) GETSTRUCT(tp))->varcreate_lsn)
+ result = true;
+
+ ReleaseSysCache(tp);
+ }
+
+ return result;
+}
+
+/*
+ * Initialize attributes cached in "svar"
+ */
+static void
+setup_session_variable(SVariable svar, Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ Assert(OidIsValid(varid));
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ svar->varid = varid;
+ svar->create_lsn = varform->varcreate_lsn;
+
+ svar->typid = varform->vartype;
+
+ get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval);
+
+ svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
+ svar->domain_check_extra = NULL;
+ svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+
+ svar->isnull = true;
+ svar->value = (Datum) 0;
+
+ svar->is_valid = true;
+
+ svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ ReleaseSysCache(tup);
+}
+
+/*
+ * Assign a new value to the session variable. It is copied to
+ * SVariableMemoryContext if necessary.
+ *
+ * If any error happens, the existing value won't be modified.
+ */
+static void
+set_session_variable(SVariable svar, Datum value, bool isnull)
+{
+ Datum newval;
+ SVariableData locsvar,
+ *_svar;
+
+ Assert(svar);
+ Assert(!isnull || value == (Datum) 0);
+
+ /*
+ * Use typbyval, typbylen from session variable only when they are
+ * trustworthy (the invalidation message was not accepted for this
+ * variable). If the variable might be invalid, force setup.
+ *
+ * Do not overwrite the passed session variable until we can be certain
+ * that no error can be thrown.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(&locsvar, svar->varid);
+ _svar = &locsvar;
+ }
+ else
+ _svar = svar;
+
+ if (!isnull)
+ {
+ MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
+
+ newval = datumCopy(value, _svar->typbyval, _svar->typlen);
+
+ MemoryContextSwitchTo(oldcxt);
+ }
+ else
+ newval = value;
+
+ free_session_variable_value(svar);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ svar->varid);
+
+ /* no more error expected, so we can overwrite the old variable now */
+ if (svar != _svar)
+ memcpy(svar, _svar, sizeof(SVariableData));
+
+ svar->value = newval;
+ svar->isnull = isnull;
+}
+
+/*
+ * Create the hash table for storing session variables.
+ */
+static void
+create_sessionvars_hashtables(void)
+{
+ HASHCTL vars_ctl;
+
+ Assert(!sessionvars);
+
+ if (!SVariableMemoryContext)
+ {
+ /* read sinval messages */
+ CacheRegisterSyscacheCallback(VARIABLEOID,
+ pg_variable_cache_callback,
+ (Datum) 0);
+
+ /* we need our own long-lived memory context */
+ SVariableMemoryContext =
+ AllocSetContextCreate(TopMemoryContext,
+ "session variables",
+ ALLOCSET_START_SMALL_SIZES);
+ }
+
+ memset(&vars_ctl, 0, sizeof(vars_ctl));
+ vars_ctl.keysize = sizeof(Oid);
+ vars_ctl.entrysize = sizeof(SVariableData);
+ vars_ctl.hcxt = SVariableMemoryContext;
+
+ sessionvars = hash_create("Session variables", 64, &vars_ctl,
+ HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+}
+
+/*
+ * Search a session variable in the hash table given its OID. If it
+ * doesn't exist, then insert it there.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the
+ * session variable until the end of the transaction.
+ */
+static SVariable
+get_session_variable(Oid varid)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect the used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (found)
+ {
+ if (!svar->is_valid)
+ {
+ /*
+ * If there was an invalidation message, the variable might still be
+ * valid, but we have to check with the system catalog.
+ */
+ if (is_session_variable_valid(svar))
+ svar->is_valid = true;
+ else
+ /* if the value cannot be validated, we have to discard it */
+ free_session_variable_value(svar);
+ }
+ }
+ else
+ svar->is_valid = false;
+
+ /*
+ * Force setup for not yet initialized variables or variables that cannot
+ * be validated.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ varid);
+ }
+
+ /* ensure the returned data is still of the correct domain */
+ if (svar->is_domain)
+ {
+ /*
+ * Store "extra" for domain_check() in TopTransactionContext. When we
+ * are in a new transaction, domain_check_extra cache is not valid any
+ * more.
+ */
+ if (svar->domain_check_extra_lxid != MyProc->vxid.lxid)
+ svar->domain_check_extra = NULL;
+
+ domain_check(svar->value, svar->isnull,
+ svar->typid, &svar->domain_check_extra,
+ TopTransactionContext);
+
+ svar->domain_check_extra_lxid = MyProc->vxid.lxid;
+ }
+
+ return svar;
+}
+
+/*
+ * Store the given value in a session variable in the cache.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the session
+ * variable until the end of the transaction.
+ */
+void
+SetSessionVariable(Oid varid, Datum value, bool isNull)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (!found)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ varid);
+ }
+
+ /* if this fails, it won't change the stored value */
+ set_session_variable(svar, value, isNull);
+}
+
+/*
+ * Returns a copy of the value stored in a variable.
+ */
+static inline Datum
+copy_session_variable_value(SVariable svar, bool *isNull)
+{
+ Datum value;
+
+ /* force copy of non NULL value */
+ if (!svar->isnull)
+ {
+ value = datumCopy(svar->value, svar->typbyval, svar->typlen);
+ *isNull = false;
+ }
+ else
+ {
+ value = (Datum) 0;
+ *isNull = true;
+ }
+
+ return value;
+}
+
+/*
+ * Returns a copy of the value of the session variable (in the current memory
+ * context). The caller is responsible for permission checks.
+ */
+Datum
+GetSessionVariable(Oid varid, bool *isNull)
+{
+ SVariable svar;
+
+ svar = get_session_variable(varid);
+
+ /*
+ * Although "svar" is freshly validated in this point, svar->is_valid can
+ * be false, if an invalidation message was processed during the domain check.
+ * But the variable and all its dependencies are locked now, so we don't need
+ * to repeat the validation.
+ */
+ return copy_session_variable_value(svar, isNull);
+}
+
+/*
+ * Assign the result of the evaluated expression to the session variable
+ */
+void
+ExecuteLetStmt(ParseState *pstate,
+ LetStmt *stmt,
+ ParamListInfo params,
+ QueryEnvironment *queryEnv,
+ QueryCompletion *qc)
+{
+ Query *query = castNode(Query, stmt->query);
+ List *rewritten;
+ DestReceiver *dest;
+ AclResult aclresult;
+ PlannedStmt *plan;
+ QueryDesc *queryDesc;
+ Oid varid = query->resultVariable;
+
+ Assert(OidIsValid(varid));
+
+ /* do we have permission to write to the session variable? */
+ aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid));
+
+ /* create a dest receiver for LET */
+ dest = CreateVariableDestReceiver(varid);
+
+ /* run the query rewriter */
+ query = copyObject(query);
+
+ rewritten = QueryRewrite(query);
+
+ Assert(list_length(rewritten) == 1);
+
+ query = linitial_node(Query, rewritten);
+ Assert(query->commandType == CMD_SELECT);
+
+ /* plan the query */
+ plan = pg_plan_query(query, pstate->p_sourcetext,
+ CURSOR_OPT_PARALLEL_OK, params);
+
+ /*
+ * Use a snapshot with an updated command ID to ensure this query sees the
+ * results of any previously executed queries. (This could only matter if
+ * the planner executed an allegedly-stable function that changed the
+ * database contents, but let's do it anyway to be parallel to the EXPLAIN
+ * code path.)
+ */
+ PushCopiedSnapshot(GetActiveSnapshot());
+ UpdateActiveSnapshotCommandId();
+
+ /* create a QueryDesc, redirecting output to our tuple receiver */
+ queryDesc = CreateQueryDesc(plan, NULL, pstate->p_sourcetext,
+ GetActiveSnapshot(), InvalidSnapshot,
+ dest, params, queryEnv, 0);
+
+ /* call ExecutorStart to prepare the plan for execution */
+ ExecutorStart(queryDesc, 0);
+
+ /*
+ * Run the plan to completion. The result should be only one row. To
+ * check if there are too many result rows, we try to fetch two.
+ */
+ ExecutorRun(queryDesc, ForwardScanDirection, 2L);
+
+ /* save the rowcount if we're given a QueryCompletion to fill */
+ if (qc)
+ SetQueryCompletion(qc, CMDTAG_LET, queryDesc->estate->es_processed);
+
+ /* and clean up */
+ ExecutorFinish(queryDesc);
+ ExecutorEnd(queryDesc);
+
+ FreeQueryDesc(queryDesc);
+
+ PopActiveSnapshot();
+}
diff --git a/src/backend/executor/Makefile b/src/backend/executor/Makefile
index 11118d0ce02..71248a34f26 100644
--- a/src/backend/executor/Makefile
+++ b/src/backend/executor/Makefile
@@ -76,6 +76,7 @@ OBJS = \
nodeWindowAgg.o \
nodeWorktablescan.o \
spi.o \
+ svariableReceiver.o \
tqueue.o \
tstoreReceiver.o
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 03566c4d181..270e6d344be 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -1041,6 +1041,38 @@ ExecInitExprRec(Expr *node, ExprState *state,
scratch.d.param.paramtype = param->paramtype;
ExprEvalPushStep(state, &scratch);
break;
+
+ case PARAM_VARIABLE:
+ {
+ int es_num_session_variables = 0;
+ SessionVariableValue *es_session_variables = NULL;
+ SessionVariableValue *var;
+
+ if (state->parent && state->parent->state)
+ {
+ es_session_variables = state->parent->state->es_session_variables;
+ es_num_session_variables = state->parent->state->es_num_session_variables;
+ }
+
+ Assert(es_session_variables);
+
+ /* parameter sanity checks */
+ if (param->paramid >= es_num_session_variables)
+ elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
+
+ var = &es_session_variables[param->paramid];
+
+ /*
+ * In this case, pass the value like a
+ * constant.
+ */
+ scratch.opcode = EEOP_CONST;
+ scratch.d.constval.value = var->value;
+ scratch.d.constval.isnull = var->isnull;
+ ExprEvalPushStep(state, &scratch);
+ }
+ break;
+
case PARAM_EXTERN:
/*
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 0493b7d5365..67e0b9ba2ac 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -43,7 +43,9 @@
#include "access/xact.h"
#include "catalog/namespace.h"
#include "catalog/partition.h"
+#include "catalog/pg_variable.h"
#include "commands/matview.h"
+#include "commands/session_variable.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/execPartition.h"
@@ -203,6 +205,70 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
Assert(queryDesc->sourceText != NULL);
estate->es_sourceText = queryDesc->sourceText;
+ /*
+ * The executor doesn't work with session variables directly. Values of
+ * related session variables are copied to a dedicated array, and this array
+ * is passed to the executor. This array is stable "snapshot" of values of
+ * used session variables. There are three benefits of this strategy:
+ *
+ * - consistency with external parameters and plpgsql variables,
+ *
+ * - session variables can be parallel safe,
+ *
+ * - we don't need make fresh copy for any read of session variable
+ * (this is necessary because the internally the session variable can
+ * be changed inside query execution time, and then a reference to
+ * previously returned value can be corrupted).
+ */
+ if (queryDesc->plannedstmt->sessionVariables)
+ {
+ int nSessionVariables;
+ int i = 0;
+
+ /*
+ * In this case, the query uses session variables, but we have to
+ * prepare the array with passed values (of used session variables)
+ * first.
+ */
+ Assert(!IsParallelWorker());
+ nSessionVariables = list_length(queryDesc->plannedstmt->sessionVariables);
+
+ /* create the array used for passing values of used session variables */
+ estate->es_session_variables = (SessionVariableValue *)
+ palloc(nSessionVariables * sizeof(SessionVariableValue));
+
+ /* fill the array */
+ foreach_oid(varid, queryDesc->plannedstmt->sessionVariables)
+ {
+ /*
+ * Permission check should be executed on all explicitly used
+ * variables in the query. For implicitly used variable
+ * (like base node of assignment indirect) we cannot do permission
+ * check, because we need read the value (and user can have
+ * only UPDATE variable). In this case the permission check
+ * is executed in write time.
+ */
+ if (varid != queryDesc->plannedstmt->exclSelectPermCheckVarid)
+ {
+ AclResult aclresult;
+
+ aclresult = object_aclcheck(VariableRelationId, varid,
+ GetUserId(), ACL_SELECT);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE,
+ get_session_variable_name(varid));
+ }
+
+ estate->es_session_variables[i].value =
+ GetSessionVariable(varid,
+ &estate->es_session_variables[i].isnull);
+
+ i++;
+ }
+
+ estate->es_num_session_variables = nSessionVariables;
+ }
+
/*
* Fill in the query environment, if any, from queryDesc.
*/
diff --git a/src/backend/executor/meson.build b/src/backend/executor/meson.build
index 2cea41f8771..491092fcc4c 100644
--- a/src/backend/executor/meson.build
+++ b/src/backend/executor/meson.build
@@ -64,6 +64,7 @@ backend_sources += files(
'nodeWindowAgg.c',
'nodeWorktablescan.c',
'spi.c',
+ 'svariableReceiver.c',
'tqueue.c',
'tstoreReceiver.c',
)
diff --git a/src/backend/executor/svariableReceiver.c b/src/backend/executor/svariableReceiver.c
new file mode 100644
index 00000000000..c6163fb36f6
--- /dev/null
+++ b/src/backend/executor/svariableReceiver.c
@@ -0,0 +1,172 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.c
+ * An implementation of DestReceiver that stores the result value in
+ * a session variable.
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/executor/svariableReceiver.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "miscadmin.h"
+
+#include "access/detoast.h"
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "storage/lock.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+/*
+ * This DestReceiver is used by the LET command for storing the result to a
+ * session variable. The result has to have only one tuple with only one
+ * non-deleted attribute. The row counter (field "rows") is incremented
+ * after receiving a row, and an error is raised when there are no rows or
+ * there are more than one received rows. A received tuple cannot to have
+ * deleted attributes. The value is detoasted before storing it in the
+ * session variable.
+ */
+typedef struct
+{
+ DestReceiver pub;
+ Oid varid;
+ bool need_detoast; /* do we need to detoast the attribute? */
+ int rows; /* row counter */
+} SVariableState;
+
+/*
+ * Prepare to receive tuples from executor.
+ */
+static void
+svariableStartupReceiver(DestReceiver *self, int operation, TupleDesc typeinfo)
+{
+ SVariableState *myState = (SVariableState *) self;
+ LOCKTAG locktag PG_USED_FOR_ASSERTS_ONLY;
+ Form_pg_attribute attr;
+ Oid typid PG_USED_FOR_ASSERTS_ONLY;
+ Oid collid PG_USED_FOR_ASSERTS_ONLY;
+ int32 typmod PG_USED_FOR_ASSERTS_ONLY;
+
+ Assert(myState->pub.mydest == DestVariable);
+ Assert(OidIsValid(myState->varid));
+ Assert(SearchSysCacheExists1(VARIABLEOID, myState->varid));
+ Assert(typeinfo->natts == 1);
+
+#ifdef USE_ASSERT_CHECKING
+
+ SET_LOCKTAG_OBJECT(locktag,
+ MyDatabaseId,
+ VariableRelationId,
+ myState->varid,
+ 0);
+
+ Assert(LockHeldByMe(&locktag, AccessShareLock, false));
+
+#endif
+
+ attr = TupleDescAttr(typeinfo, 0);
+
+ Assert(!attr->attisdropped);
+
+#ifdef USE_ASSERT_CHECKING
+
+ get_session_variable_type_typmod_collid(myState->varid,
+ &typid,
+ &typmod,
+ &collid);
+
+ Assert(attr->atttypid == typid);
+ Assert(attr->atttypmod < 0 || attr->atttypmod == typmod);
+
+#endif
+
+ myState->need_detoast = attr->attlen == -1;
+ myState->rows = 0;
+}
+
+/*
+ * Receive a tuple from the executor and store it in the session variable.
+ */
+static bool
+svariableReceiveSlot(TupleTableSlot *slot, DestReceiver *self)
+{
+ SVariableState *myState = (SVariableState *) self;
+ Datum value;
+ bool isnull;
+ bool freeval = false;
+
+ /* make sure the tuple is fully deconstructed */
+ slot_getallattrs(slot);
+
+ value = slot->tts_values[0];
+ isnull = slot->tts_isnull[0];
+
+ if (myState->need_detoast && !isnull && VARATT_IS_EXTERNAL(DatumGetPointer(value)))
+ {
+ value = PointerGetDatum(detoast_external_attr((struct varlena *)
+ DatumGetPointer(value)));
+ freeval = true;
+ }
+
+ myState->rows += 1;
+
+ if (myState->rows > 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_TOO_MANY_ROWS),
+ errmsg("expression returned more than one row")));
+
+ SetSessionVariable(myState->varid, value, isnull);
+
+ if (freeval)
+ pfree(DatumGetPointer(value));
+
+ return true;
+}
+
+/*
+ * Clean up at end of the executor run
+ */
+static void
+svariableShutdownReceiver(DestReceiver *self)
+{
+ if (((SVariableState *) self)->rows == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_NO_DATA_FOUND),
+ errmsg("expression returned no rows")));
+}
+
+/*
+ * Destroy the receiver when we are done with it
+ */
+static void
+svariableDestroyReceiver(DestReceiver *self)
+{
+ pfree(self);
+}
+
+/*
+ * Initially create a DestReceiver object.
+ */
+DestReceiver *
+CreateVariableDestReceiver(Oid varid)
+{
+ SVariableState *self = (SVariableState *) palloc0(sizeof(SVariableState));
+
+ self->pub.receiveSlot = svariableReceiveSlot;
+ self->pub.rStartup = svariableStartupReceiver;
+ self->pub.rShutdown = svariableShutdownReceiver;
+ self->pub.rDestroy = svariableDestroyReceiver;
+ self->pub.mydest = DestVariable;
+
+ self->varid = varid;
+
+ return (DestReceiver *) self;
+}
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f1..d8fc3d9fa69 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4375,6 +4375,16 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_LetStmt:
+ {
+ LetStmt *stmt = (LetStmt *) node;
+
+ if (WALK(stmt->target))
+ return true;
+ if (WALK(stmt->query))
+ return true;
+ }
+ break;
case T_PLAssignStmt:
{
PLAssignStmt *stmt = (PLAssignStmt *) node;
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 7b1a8a0a9f1..cf094987569 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -333,6 +333,21 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
glob->lastPlanNodeId = 0;
glob->transientPlan = false;
glob->dependsOnRole = false;
+ glob->sessionVariables = NIL;
+
+ /*
+ * The (session) result variable should be stored to global, because
+ * it is not set in subquery. When this variable is used other than
+ * in base node of assignment indirection, we need to check the access
+ * rights (and then we need to detect this situation). The variable used
+ * like base node cannot be different than target (result) variable.
+ * Because we know the result variable before planner invocation, we
+ * can simply search of usage just this variable, and we don't need to
+ * to wait until the end of planning when we know basenodeSessionVarid.
+ */
+ glob->resultVariable = parse->resultVariable;
+ glob->basenodeSessionVarid = InvalidOid;
+ glob->basenodeSessionVarSelectCheck = false;
/*
* Assess whether it's feasible to use parallel mode for this query. We
@@ -570,6 +585,20 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
result->paramExecTypes = glob->paramExecTypes;
/* utilityStmt should be null, but we might as well copy it */
result->utilityStmt = parse->utilityStmt;
+
+ result->sessionVariables = glob->sessionVariables;
+
+ /*
+ * The session variable used (and only used) like base node
+ * for assignemnt indirection should be excluded from permission
+ * check.
+ */
+ if (OidIsValid(glob->basenodeSessionVarid) &&
+ (!glob->basenodeSessionVarSelectCheck))
+ result->exclSelectPermCheckVarid = glob->basenodeSessionVarid;
+ else
+ result->exclSelectPermCheckVarid = InvalidOid;
+
result->stmt_location = parse->stmt_location;
result->stmt_len = parse->stmt_len;
@@ -740,6 +769,13 @@ subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root,
*/
pull_up_subqueries(root);
+ /*
+ * Check if some subquery uses a session variable. The flag
+ * hasSessionVariables should be true if the query or some subquery uses a
+ * session variable.
+ */
+ pull_up_has_session_variables(root);
+
/*
* If this is a simple UNION ALL query, flatten it into an appendrel. We
* do this now because it requires applying pull_up_subqueries to the leaf
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 999a5a8ab5a..dc2caa520f7 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -210,6 +210,9 @@ static List *set_returning_clause_references(PlannerInfo *root,
static List *set_windowagg_runcondition_references(PlannerInfo *root,
List *runcondition,
Plan *plan);
+static bool pull_up_has_session_variables_walker(Node *node,
+ PlannerInfo *root);
+static void record_plan_variable_dependency(PlannerInfo *root, Oid varid);
/*****************************************************************************
@@ -1315,6 +1318,50 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
return plan;
}
+/*
+ * Search usage of session variables in subqueries
+ */
+void
+pull_up_has_session_variables(PlannerInfo *root)
+{
+ Query *query = root->parse;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ }
+ else
+ {
+ (void) query_tree_walker(query,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+}
+
+static bool
+pull_up_has_session_variables_walker(Node *node, PlannerInfo *root)
+{
+ if (node == NULL)
+ return false;
+ if (IsA(node, Query))
+ {
+ Query *query = (Query *) node;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ return false;
+ }
+
+ /* recurse into subselects */
+ return query_tree_walker((Query *) node,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+ return expression_tree_walker(node, pull_up_has_session_variables_walker,
+ (void *) root);
+}
+
/*
* set_indexonlyscan_references
* Do set_plan_references processing on an IndexOnlyScan
@@ -2015,8 +2062,9 @@ copyVar(Var *var)
* This is code that is common to all variants of expression-fixing.
* We must look up operator opcode info for OpExpr and related nodes,
* add OIDs from regclass Const nodes into root->glob->relationOids, and
- * add PlanInvalItems for user-defined functions into root->glob->invalItems.
- * We also fill in column index lists for GROUPING() expressions.
+ * add PlanInvalItems for user-defined functions and session variables into
+ * root->glob->invalItems. We also fill in column index lists for GROUPING()
+ * expressions.
*
* We assume it's okay to update opcode info in-place. So this could possibly
* scribble on the planner's input data structures, but it's OK.
@@ -2106,6 +2154,13 @@ fix_expr_common(PlannerInfo *root, Node *node)
g->cols = cols;
}
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ record_plan_variable_dependency(root, p->paramvarid);
+ }
}
/*
@@ -2115,6 +2170,10 @@ fix_expr_common(PlannerInfo *root, Node *node)
* If it's a PARAM_MULTIEXPR, replace it with the appropriate Param from
* root->multiexpr_params; otherwise no change is needed.
* Just for paranoia's sake, we make a copy of the node in either case.
+ *
+ * If it's a PARAM_VARIABLE, then we collect used session variables in
+ * the list root->glob->sessionVariable. Also, assign the parameter's
+ * "paramid" to the parameter's position in that list.
*/
static Node *
fix_param_node(PlannerInfo *root, Param *p)
@@ -2133,6 +2192,62 @@ fix_param_node(PlannerInfo *root, Param *p)
elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid);
return copyObject(list_nth(params, colno - 1));
}
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ int n = 0;
+ bool found = false;
+
+ /* we will modify object */
+ p = (Param *) copyObject(p);
+
+ /*
+ * Now, we can actualize list of session variables, and we can
+ * complete paramid parameter.
+ */
+ foreach_oid(varid, root->glob->sessionVariables)
+ {
+ if (varid == p->paramvarid)
+ {
+ p->paramid = n;
+ found = true;
+ break;
+ }
+ n += 1;
+ }
+
+ if (!found)
+ {
+ root->glob->sessionVariables = lappend_oid(root->glob->sessionVariables,
+ p->paramvarid);
+ p->paramid = n;
+ }
+
+ /*
+ * We do SELECT permission check of all variables used by
+ * the query excluding the variable that is used only as base node
+ * of assignment indirection. The variable id assigned to this param
+ * should be same like resultVariable id, and this param should be
+ * used only once in query. When the variable is referenced by any
+ * other param, we should to do SELECT permission check for this variable
+ * too.
+ */
+ if (p->parambasenode)
+ {
+ Assert(!OidIsValid(root->glob->basenodeSessionVarid));
+ Assert(root->glob->resultVariable == p->paramvarid);
+
+ root->glob->basenodeSessionVarid = p->paramvarid;
+ }
+ else
+ {
+ if (p->paramvarid == root->glob->resultVariable)
+ root->glob->basenodeSessionVarSelectCheck = true;
+ }
+
+ return (Node *) p;
+ }
+
return (Node *) copyObject(p);
}
@@ -2194,7 +2309,10 @@ fix_alternative_subplan(PlannerInfo *root, AlternativeSubPlan *asplan,
* replacing Aggref nodes that should be replaced by initplan output Params,
* choosing the best implementation for AlternativeSubPlans,
* looking up operator opcode info for OpExpr and related nodes,
- * and adding OIDs from regclass Const nodes into root->glob->relationOids.
+ * adding OIDs from regclass Const nodes into root->glob->relationOids,
+ * assigning paramvarid to PARAM_VARIABLE params, and collecting the
+ * OIDs of session variables in the root->glob->sessionVariables list
+ * (paramvarid is the position of the session variable in this list).
*
* 'node': the expression to be modified
* 'rtoffset': how much to increment varnos by
@@ -2216,7 +2334,8 @@ fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec)
root->multiexpr_params != NIL ||
root->glob->lastPHId != 0 ||
root->minmax_aggs != NIL ||
- root->hasAlternativeSubPlans)
+ root->hasAlternativeSubPlans ||
+ root->hasSessionVariables)
{
return fix_scan_expr_mutator(node, &context);
}
@@ -3609,6 +3728,25 @@ record_plan_type_dependency(PlannerInfo *root, Oid typid)
}
}
+/*
+ * Record dependency on a session variable. The variable can be used as a
+ * session variable in an expression list, or as the target of a LET statement.
+ */
+static void
+record_plan_variable_dependency(PlannerInfo *root, Oid varid)
+{
+ PlanInvalItem *inval_item = makeNode(PlanInvalItem);
+
+ /* paramid is still session variable id */
+ inval_item->cacheId = VARIABLEOID;
+ inval_item->hashValue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ /* append this variable to global, register dependency */
+ root->glob->invalItems = lappend(root->glob->invalItems,
+ inval_item);
+}
+
/*
* extract_query_dependencies
* Given a rewritten, but not yet planned, query or queries
@@ -3694,9 +3832,9 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
}
/*
- * Ignore other utility statements, except those (such as EXPLAIN)
- * that contain a parsed-but-not-planned query. For those, we
- * just need to transfer our attention to the contained query.
+ * Ignore other utility statements, except those (such as EXPLAIN
+ * or LET) that contain a parsed-but-not-planned query. For those,
+ * we just need to transfer our attention to the contained query.
*/
query = UtilityContainsQuery(query->utilityStmt);
if (query == NULL)
@@ -3719,6 +3857,10 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
lappend_oid(context->glob->relationOids, rte->relid);
}
+ /* record dependency on the target variable of a LET command */
+ if (OidIsValid(query->resultVariable))
+ record_plan_variable_dependency(context, query->resultVariable);
+
/* And recurse into the query's subexpressions */
return query_tree_walker(query, extract_query_dependencies_walker,
context, 0);
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index 5d9225e9909..71479ceb1bc 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -1432,6 +1432,9 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
/* If subquery had any RLS conditions, now main query does too */
parse->hasRowSecurity |= subquery->hasRowSecurity;
+ /* if the subquery had session variables, the main query does too */
+ parse->hasSessionVariables |= subquery->hasSessionVariables;
+
/*
* subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
* hasTargetSRFs, so no work needed on those flags
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 43dfecfb47f..f60828f862e 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -24,6 +24,7 @@
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "commands/session_variable.h"
#include "executor/executor.h"
#include "executor/functions.h"
#include "funcapi.h"
@@ -934,6 +935,13 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
if (param->paramkind == PARAM_EXTERN)
return false;
+ /* we don't support passing session variables to workers */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
+ return true;
+ }
+
if (param->paramkind != PARAM_EXEC ||
!list_member_int(context->safe_param_ids, param->paramid))
{
@@ -2389,6 +2397,7 @@ convert_saop_to_hashed_saop_walker(Node *node, void *context)
* value of the Param.
* 2. Fold stable, as well as immutable, functions to constants.
* 3. Reduce PlaceHolderVar nodes to their contained expressions.
+ * 4. Current value of session variable can be used for estimation too.
*--------------------
*/
Node *
@@ -2515,6 +2524,27 @@ eval_const_expressions_mutator(Node *node,
}
}
}
+ else if (param->paramkind == PARAM_VARIABLE &&
+ context->estimate)
+ {
+ int16 typLen;
+ bool typByVal;
+ Datum pval;
+ bool isnull;
+
+ get_typlenbyval(param->paramtype,
+ &typLen, &typByVal);
+
+ pval = GetSessionVariable(param->paramvarid, &isnull);
+
+ return (Node *) makeConst(param->paramtype,
+ param->paramtypmod,
+ param->paramcollid,
+ (int) typLen,
+ pval,
+ isnull,
+ typByVal);
+ }
/*
* Not replaceable, so just copy the Param (no need to
@@ -4720,7 +4750,8 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
querytree->limitOffset ||
querytree->limitCount ||
querytree->setOperations ||
- list_length(querytree->targetList) != 1)
+ (list_length(querytree->targetList) != 1) ||
+ querytree->hasSessionVariables)
goto fail;
/* If the function result is composite, resolve it */
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 76f58b3aca3..725f678e2fa 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -25,9 +25,12 @@
#include "postgres.h"
#include "access/sysattr.h"
+#include "catalog/namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
@@ -51,6 +54,7 @@
#include "utils/backend_status.h"
#include "utils/builtins.h"
#include "utils/guc.h"
+#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
@@ -83,6 +87,8 @@ static Query *transformCreateTableAsStmt(ParseState *pstate,
CreateTableAsStmt *stmt);
static Query *transformCallStmt(ParseState *pstate,
CallStmt *stmt);
+static Query *transformLetStmt(ParseState *pstate,
+ LetStmt *stmt);
static void transformLockingClause(ParseState *pstate, Query *qry,
LockingClause *lc, bool pushedDown);
#ifdef DEBUG_NODE_TESTS_ENABLED
@@ -414,6 +420,7 @@ transformStmt(ParseState *pstate, Node *parseTree)
case T_UpdateStmt:
case T_DeleteStmt:
case T_MergeStmt:
+ case T_LetStmt:
(void) test_raw_expression_coverage(parseTree, NULL);
break;
default:
@@ -493,6 +500,11 @@ transformStmt(ParseState *pstate, Node *parseTree)
(CallStmt *) parseTree);
break;
+ case T_LetStmt:
+ result = transformLetStmt(pstate,
+ (LetStmt *) parseTree);
+ break;
+
default:
/*
@@ -545,6 +557,7 @@ stmt_requires_parse_analysis(RawStmt *parseTree)
case T_SelectStmt:
case T_ReturnStmt:
case T_PLAssignStmt:
+ case T_LetStmt:
result = true;
break;
@@ -653,6 +666,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1078,6 +1092,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1543,6 +1558,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, stmt->lockingClause)
{
@@ -1769,12 +1785,241 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
return qry;
}
+/*
+ * transformLetStmt -
+ * transform an Let Statement
+ */
+static Query *
+transformLetStmt(ParseState *pstate, LetStmt *stmt)
+{
+ Query *query;
+ Query *result;
+ List *exprList = NIL;
+ List *exprListCoer = NIL;
+ ListCell *lc;
+ ListCell *indirection_head = NULL;
+ Query *selectQuery;
+ Oid varid;
+ char *attrname = NULL;
+ bool not_unique;
+ bool is_rowtype;
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+ List *names = NULL;
+ int indirection_start;
+ int i = 0;
+
+ /* there can't be any outer WITH to worry about */
+ Assert(pstate->p_ctenamespace == NIL);
+
+ names = NamesFromList(stmt->target);
+
+ /* locks the variable with an AccessShareLock */
+ varid = IdentifyVariable(names, &attrname, ¬_unique, false);
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("target \"%s\" of LET command is ambiguous",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ if (!OidIsValid(varid))
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ /*
+ * Calculate start of possible position of an indirection in list, and
+ * when it is inside the list, store pointer on first node of indirection.
+ */
+ indirection_start = list_length(names) - (attrname ? 1 : 0);
+ if (list_length(stmt->target) > indirection_start)
+ indirection_head = list_nth_cell(stmt->target, indirection_start);
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod, &collid);
+
+ is_rowtype = type_is_rowtype(typid);
+
+ if (attrname && !is_rowtype)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("cannot assign to field \"%s\" of session variable \"%s.%s\" because its type %s is not a composite type",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->location)));
+
+ pstate->p_expr_kind = EXPR_KIND_LET_TARGET;
+
+ /* we need to postpone conversion of "unknown" to text */
+ pstate->p_resolve_unknowns = false;
+
+ selectQuery = transformStmt(pstate, stmt->query);
+
+ /* the grammar should have produced a SELECT */
+ Assert(IsA(selectQuery, Query) && selectQuery->commandType == CMD_SELECT);
+
+ /*
+ * Generate an expression list for the LET that selects all the non-resjunk
+ * columns from the subquery.
+ */
+ exprList = NIL;
+ foreach_node(TargetEntry, tle, selectQuery->targetList)
+ {
+ if (tle->resjunk)
+ continue;
+
+ exprList = lappend(exprList, tle->expr);
+ }
+
+ /* don't allow multicolumn result */
+ if (list_length(exprList) != 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg_plural("assignment expression returned %d column",
+ "assignment expression returned %d columns",
+ list_length(exprList),
+ list_length(exprList)),
+ parser_errposition(pstate,
+ exprLocation((Node *) exprList))));
+
+ exprListCoer = NIL;
+
+ foreach(lc, exprList)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ Expr *coerced_expr;
+ Oid exprtypid;
+
+ /* now we can read the type of the expression */
+ exprtypid = exprType((Node *) expr);
+
+ if (indirection_head)
+ {
+ bool targetIsArray;
+ char *targetName;
+ Param *param;
+
+ targetName = get_session_variable_name(varid);
+ targetIsArray = OidIsValid(get_element_type(typid));
+
+ pstate->p_hasSessionVariables = true;
+
+ param = makeNode(Param);
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+
+ /*
+ * The parameter used as basenode has to have special
+ * mark, because requires special access when we do
+ * SELECT access check.
+ */
+ param->parambasenode = true;
+
+ coerced_expr = (Expr *)
+ transformAssignmentIndirection(pstate,
+ (Node *) param,
+ targetName,
+ targetIsArray,
+ typid,
+ typmod,
+ InvalidOid,
+ stmt->target,
+ indirection_head,
+ (Node *) expr,
+ COERCION_ASSIGNMENT,
+ stmt->location);
+ }
+ else
+ coerced_expr = (Expr *)
+ coerce_to_target_type(pstate,
+ (Node *) expr,
+ exprtypid,
+ typid, typmod,
+ COERCION_ASSIGNMENT,
+ COERCE_IMPLICIT_CAST,
+ stmt->location);
+
+ if (coerced_expr == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("variable \"%s.%s\" is of type %s, but expression is of type %s",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid),
+ format_type_be(exprtypid)),
+ errhint("You will need to rewrite or cast the expression."),
+ parser_errposition(pstate, exprLocation((Node *) expr))));
+
+ exprListCoer = lappend(exprListCoer, coerced_expr);
+ }
+
+ /* generate query's target list using the computed list of expressions */
+ query = makeNode(Query);
+ query->commandType = CMD_SELECT;
+
+ foreach(lc, exprListCoer)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ TargetEntry *tle;
+
+ tle = makeTargetEntry(expr,
+ i + 1,
+ FigureColname((Node *) expr),
+ false);
+ query->targetList = lappend(query->targetList, tle);
+ }
+
+ /* done building the range table and jointree */
+ query->rtable = pstate->p_rtable;
+ query->jointree = makeFromExpr(pstate->p_joinlist, NULL);
+
+ query->hasTargetSRFs = pstate->p_hasTargetSRFs;
+ query->hasSubLinks = pstate->p_hasSubLinks;
+ query->hasSessionVariables = pstate->p_hasSessionVariables;
+
+ /* this is top-level query */
+ query->canSetTag = true;
+
+ /*
+ * Save target session variable ID. It is used later for
+ * acquiring an AccessShareLock on target variable, setting
+ * plan dependency and finally for creating VariableDestReceiver.
+ */
+ query->resultVariable = varid;
+
+ assign_query_collations(pstate, query);
+
+ /*
+ * The query is executed as utility command by nested executor call.
+ * Assigned queryId is required in this case.
+ */
+ if (IsQueryIdEnabled())
+ JumbleQuery(query);
+
+ stmt->query = (Node *) query;
+
+ /* represent the command as a utility Query */
+ result = makeNode(Query);
+ result->commandType = CMD_UTILITY;
+ result->utilityStmt = (Node *) stmt;
+
+ return result;
+}
+
/*
* transformSetOperationStmt -
* transforms a set-operations tree
@@ -2020,6 +2265,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, lockingClause)
{
@@ -2495,6 +2741,7 @@ transformReturnStmt(ParseState *pstate, ReturnStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2562,6 +2809,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2852,9 +3100,15 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
/*
* Transform the target reference. Typically we will get back a Param
* node, but there's no reason to be too picky about its type.
+ *
+ * Session variables should not be used as target of a PL/pgSQL assign
+ * statement. So we should use a dedicated expression kind and disallow
+ * session variables there. The dedicated context allows to eliminate
+ * undesirable warnings about the possibility of a target PL/pgSQL variable
+ * shadowing a session variable.
*/
target = transformExpr(pstate, (Node *) cref,
- EXPR_KIND_UPDATE_TARGET);
+ EXPR_KIND_ASSIGN_TARGET);
targettype = exprType(target);
targettypmod = exprTypmod(target);
targetcollation = exprCollation(target);
@@ -2896,6 +3150,10 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
*/
type_id = exprType((Node *) tle->expr);
+ /*
+ * For indirection processing and additional casts we can use expr_kind
+ * EXPR_KIND_UPDATE_TARGET.
+ */
pstate->p_expr_kind = EXPR_KIND_UPDATE_TARGET;
if (indirection)
@@ -3038,6 +3296,8 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
(LockingClause *) lfirst(l), false);
}
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
+
assign_query_collations(pstate, qry);
/* this must be done after collations, for reliable comparison of exprs */
@@ -3311,6 +3571,16 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt)
true,
stmt->funccall->location);
+ /*
+ * The arguments of CALL statement are evaluated by a direct expression
+ * executor call. This path is unsupported yet, so block it. It will be
+ * enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
assign_expr_collations(pstate, node);
fexpr = castNode(FuncExpr, node);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 6c95950b99b..04251bba456 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -297,7 +297,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
DropTransformStmt
DropUserMappingStmt ExplainStmt FetchStmt
GrantStmt GrantRoleStmt ImportForeignSchemaStmt IndexStmt InsertStmt
- ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
+ LetStmt ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
CreateFunctionStmt AlterFunctionStmt ReindexStmt RemoveAggrStmt
RemoveFuncStmt RemoveOperStmt RenameStmt ReturnStmt RevokeStmt RevokeRoleStmt
RuleActionStmt RuleActionStmtOrEmpty RuleStmt
@@ -742,7 +742,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
KEEP KEY KEYS
LABEL LANGUAGE LARGE_P LAST_P LATERAL_P
- LEADING LEAKPROOF LEAST LEFT LEVEL LIKE LIMIT LISTEN LOAD LOCAL
+ LEADING LEAKPROOF LEAST LEFT LET LEVEL LIKE LIMIT LISTEN LOAD LOCAL
LOCALTIME LOCALTIMESTAMP LOCATION LOCK_P LOCKED LOGGED
MAPPING MATCH MATCHED MATERIALIZED MAXVALUE MERGE MERGE_ACTION METHOD
@@ -1089,6 +1089,7 @@ stmt:
| ImportForeignSchemaStmt
| IndexStmt
| InsertStmt
+ | LetStmt
| ListenStmt
| RefreshMatViewStmt
| LoadStmt
@@ -12845,6 +12846,38 @@ opt_hold: /* EMPTY */ { $$ = 0; }
| WITHOUT HOLD { $$ = 0; }
;
+/*****************************************************************************
+ *
+ * QUERY:
+ * LET STATEMENT
+ *
+ *****************************************************************************/
+LetStmt: LET ColId opt_indirection '=' a_expr
+ {
+ LetStmt *n = makeNode(LetStmt);
+ SelectStmt *select;
+ ResTarget *res;
+
+ n->target = lcons(makeString($2),
+ check_indirection($3, yyscanner));
+
+ select = makeNode(SelectStmt);
+ res = makeNode(ResTarget);
+
+ /* create target list for implicit query */
+ res->name = NULL;
+ res->indirection = NIL;
+ res->val = (Node *) $5;
+ res->location = @5;
+
+ select->targetList = list_make1(res);
+ n->query = (Node *) select;
+
+ n->location = @2;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* QUERY:
@@ -17916,6 +17949,7 @@ unreserved_keyword:
| LARGE_P
| LAST_P
| LEAKPROOF
+ | LET
| LEVEL
| LISTEN
| LOAD
@@ -18529,6 +18563,7 @@ bare_label_keyword:
| LEAKPROOF
| LEAST
| LEFT
+ | LET
| LEVEL
| LIKE
| LISTEN
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 9e567f3cc45..4737b04d171 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -580,6 +580,11 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
+
/*
* There is intentionally no default: case here, so that the
* compiler will warn if we add a new ParseExprKind without
@@ -970,6 +975,10 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
case EXPR_KIND_CYCLE_MARK:
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index bad1df732ea..4f208c7efdd 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -17,6 +17,7 @@
#include "catalog/pg_aggregate.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
@@ -33,11 +34,13 @@
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "parser/parse_type.h"
+#include "storage/lmgr.h"
#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/timestamp.h"
+#include "utils/typcache.h"
#include "utils/xml.h"
/* GUC parameters */
@@ -106,6 +109,9 @@ static Expr *make_distinct_op(ParseState *pstate, List *opname,
Node *ltree, Node *rtree, int location);
static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
+static Node *makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location);
/*
@@ -499,6 +505,89 @@ transformIndirection(ParseState *pstate, A_Indirection *ind)
return result;
}
+/*
+ * Returns true if the given expression kind is valid for session variables.
+ * Session variables can be used everywhere where external parameters can be
+ * used. Session variables are not allowed in DDL commands or in constraints.
+ *
+ * An identifier can be parsed as a session variable only for expression kinds
+ * where session variables are allowed. This is the primary usage of this
+ * function.
+ *
+ * The second usage of this function is to decide whether a "column does not
+ * exist" or a "column or variable does not exist" error message should be
+ * printed. When we are in an expression where session variables cannot be
+ * used, we raise the first form of error message.
+ */
+static bool
+expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
+{
+ bool result = false;
+
+ switch (p_expr_kind)
+ {
+ case EXPR_KIND_NONE:
+ Assert(false); /* can't happen */
+ return false;
+
+ /* session variables allowed */
+ case EXPR_KIND_OTHER:
+ case EXPR_KIND_JOIN_ON:
+ case EXPR_KIND_FROM_SUBSELECT:
+ case EXPR_KIND_FROM_FUNCTION:
+ case EXPR_KIND_WHERE:
+ case EXPR_KIND_HAVING:
+ case EXPR_KIND_FILTER:
+ case EXPR_KIND_WINDOW_PARTITION:
+ case EXPR_KIND_WINDOW_ORDER:
+ case EXPR_KIND_WINDOW_FRAME_RANGE:
+ case EXPR_KIND_WINDOW_FRAME_ROWS:
+ case EXPR_KIND_WINDOW_FRAME_GROUPS:
+ case EXPR_KIND_SELECT_TARGET:
+ case EXPR_KIND_INSERT_TARGET:
+ case EXPR_KIND_UPDATE_SOURCE:
+ case EXPR_KIND_UPDATE_TARGET:
+ case EXPR_KIND_MERGE_WHEN:
+ case EXPR_KIND_MERGE_RETURNING:
+ case EXPR_KIND_GROUP_BY:
+ case EXPR_KIND_ORDER_BY:
+ case EXPR_KIND_DISTINCT_ON:
+ case EXPR_KIND_LIMIT:
+ case EXPR_KIND_OFFSET:
+ case EXPR_KIND_RETURNING:
+ case EXPR_KIND_VALUES:
+ case EXPR_KIND_VALUES_SINGLE:
+ case EXPR_KIND_ALTER_COL_TRANSFORM:
+ case EXPR_KIND_EXECUTE_PARAMETER:
+ case EXPR_KIND_POLICY:
+ case EXPR_KIND_CALL_ARGUMENT:
+ case EXPR_KIND_COPY_WHERE:
+ case EXPR_KIND_LET_TARGET:
+ result = true;
+ break;
+
+ /* session variables not allowed */
+ case EXPR_KIND_CHECK_CONSTRAINT:
+ case EXPR_KIND_DOMAIN_CHECK:
+ case EXPR_KIND_COLUMN_DEFAULT:
+ case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_INDEX_EXPRESSION:
+ case EXPR_KIND_INDEX_PREDICATE:
+ case EXPR_KIND_STATS_EXPRESSION:
+ case EXPR_KIND_TRIGGER_WHEN:
+ case EXPR_KIND_PARTITION_BOUND:
+ case EXPR_KIND_PARTITION_EXPRESSION:
+ case EXPR_KIND_GENERATED_COLUMN:
+ case EXPR_KIND_JOIN_USING:
+ case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ result = false;
+ break;
+ }
+
+ return result;
+}
+
/*
* Transform a ColumnRef.
*
@@ -575,6 +664,8 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
case EXPR_KIND_COPY_WHERE:
case EXPR_KIND_GENERATED_COLUMN:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
@@ -847,8 +938,61 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
}
/*
- * Throw error if no translation found.
+ * There are contexts where session variables are not allowed. We don't
+ * need to identify session variables in such a context, but identifying
+ * them allows us to raise meaningful error messages like "you cannot use
+ * session variables here".
*/
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind))
+ {
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* -----
+ * Session variables are shadowed by columns, routine variables or
+ * routine arguments. We certainly don't want to use a session variable
+ * when it is exactly shadowed, but a RTE like this is conceivable:
+ *
+ * CREATE TYPE t AS (c int);
+ * CREATE VARIABLE foo AS t;
+ * CREATE TABLE foo(a int, b int);
+ *
+ * SELECT foo.a, foo.b, foo.c FROM foo;
+ *
+ * However, that is very confusing, so we disallow it. We don't try to
+ * identify a variable if we know that it would be shadowed.
+ * -----
+ */
+ if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ {
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(cref->fields)),
+ parser_errposition(pstate, cref->location)));
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ node = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, cref->location);
+ }
+ }
+ }
+
+ /* throw an error if no translation was found */
if (node == NULL)
{
switch (crerr)
@@ -880,6 +1024,75 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
return node;
}
+/*
+ * Generate param variable for reference to session variable
+ */
+static Node *
+makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location)
+{
+ Param *param;
+
+ param = makeNode(Param);
+
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+ param->paramcollid = collid;
+
+ pstate->p_hasSessionVariables = true;
+
+ if (attrname != NULL)
+ {
+ TupleDesc tupdesc;
+ int i;
+
+ tupdesc = lookup_rowtype_tupdesc_noerror(typid, typmod, true);
+ if (!tupdesc)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("variable \"%s.%s\" is of type \"%s\", which is not a composite type",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, location)));
+
+ for (i = 0; i < tupdesc->natts; i++)
+ {
+ Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+ if (strcmp(attrname, NameStr(att->attname)) == 0 &&
+ !att->attisdropped)
+ {
+ /* success, so generate a FieldSelect expression */
+ FieldSelect *fselect = makeNode(FieldSelect);
+
+ fselect->arg = (Expr *) param;
+ fselect->fieldnum = i + 1;
+ fselect->resulttype = att->atttypid;
+ fselect->resulttypmod = att->atttypmod;
+ /* save attribute's collation for parse_collate.c */
+ fselect->resultcollid = att->attcollation;
+
+ ReleaseTupleDesc(tupdesc);
+ return (Node *) fselect;
+ }
+ }
+
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_COLUMN),
+ errmsg("could not identify column \"%s\" in variable \"%s.%s\"",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ parser_errposition(pstate, location)));
+ }
+
+ return (Node *) param;
+}
+
static Node *
transformParamRef(ParseState *pstate, ParamRef *pref)
{
@@ -1815,6 +2028,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_VALUES:
case EXPR_KIND_VALUES_SINGLE:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
case EXPR_KIND_CHECK_CONSTRAINT:
@@ -1858,6 +2072,9 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_GENERATED_COLUMN:
err = _("cannot use subquery in column generation expression");
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ err = _("cannot use subquery as target of assign statement");
+ break;
/*
* There is intentionally no default: case here, so that the
@@ -3207,6 +3424,10 @@ ParseExprKindName(ParseExprKind exprKind)
return "GENERATED AS";
case EXPR_KIND_CYCLE_MARK:
return "CYCLE";
+ case EXPR_KIND_ASSIGN_TARGET:
+ return "ASSIGN";
+ case EXPR_KIND_LET_TARGET:
+ return "LET";
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index 583bbbf232f..dc25f6dcd0e 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2656,6 +2656,8 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location)
err = _("set-returning functions are not allowed in column generation expressions");
break;
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
errkind = true;
break;
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
index 51d7703eff7..244efcddf32 100644
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -405,6 +405,7 @@ transformMergeStmt(ParseState *pstate, MergeStmt *stmt)
qry->hasTargetSRFs = false;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c
index b44f9072280..446c71953bf 100644
--- a/src/backend/tcop/dest.c
+++ b/src/backend/tcop/dest.c
@@ -38,6 +38,7 @@
#include "executor/functions.h"
#include "executor/tqueue.h"
#include "executor/tstoreReceiver.h"
+#include "executor/svariableReceiver.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
@@ -155,6 +156,9 @@ CreateDestReceiver(CommandDest dest)
case DestExplainSerialize:
return CreateExplainSerializeDestReceiver(NULL);
+
+ case DestVariable:
+ return CreateVariableDestReceiver(InvalidOid);
}
/* should never get here */
@@ -191,6 +195,7 @@ EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_o
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -237,6 +242,7 @@ NullCommand(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -281,6 +287,7 @@ ReadyForQuery(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 99a51877d34..7a508a3644f 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -49,6 +49,7 @@
#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
+#include "commands/session_variable.h"
#include "commands/subscriptioncmds.h"
#include "commands/tablecmds.h"
#include "commands/tablespace.h"
@@ -235,6 +236,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CallStmt:
case T_DoStmt:
+ case T_LetStmt:
{
/*
* Commands inside the DO block or the called procedure might
@@ -1067,6 +1069,11 @@ standard_ProcessUtility(PlannedStmt *pstmt,
break;
}
+ case T_LetStmt:
+ ExecuteLetStmt(pstate, (LetStmt *) parsetree, params,
+ queryEnv, qc);
+ break;
+
default:
/* All other statement types have event trigger support */
ProcessUtilitySlow(pstate, pstmt, queryString,
@@ -2206,6 +2213,10 @@ UtilityContainsQuery(Node *parsetree)
return UtilityContainsQuery(qry->utilityStmt);
return qry;
+ case T_LetStmt:
+ qry = castNode(Query, ((LetStmt *) parsetree)->query);
+ return qry;
+
default:
return NULL;
}
@@ -2404,6 +2415,10 @@ CreateCommandTag(Node *parsetree)
tag = CMDTAG_SELECT;
break;
+ case T_LetStmt:
+ tag = CMDTAG_LET;
+ break;
+
/* utility statements --- same whether raw or cooked */
case T_TransactionStmt:
{
@@ -3289,6 +3304,7 @@ GetCommandLogLevel(Node *parsetree)
break;
case T_PLAssignStmt:
+ case T_LetStmt:
lev = LOGSTMT_ALL;
break;
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 54dad975553..7417054c38f 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -37,6 +37,7 @@
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablespace.h"
#include "common/keywords.h"
@@ -531,6 +532,7 @@ static char *generate_function_name(Oid funcid, int nargs,
static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2);
static void add_cast_to(StringInfo buf, Oid typid);
static char *generate_qualified_type_name(Oid typid);
+static char *generate_session_variable_name(Oid varid);
static text *string_to_text(char *str);
static char *flatten_reloptions(Oid relid);
static void get_reloptions(StringInfo buf, Datum reloptions);
@@ -8677,6 +8679,14 @@ get_parameter(Param *param, deparse_context *context)
return;
}
+ /* translate paramvarid to session variable name */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ return;
+ }
+
/*
* Alternatively, maybe it's a subplan output, which we print as a
* reference to the subplan. (We could drill down into the subplan and
@@ -13477,6 +13487,42 @@ generate_collation_name(Oid collid)
return result;
}
+/*
+ * generate_session_variable_name
+ * Compute the name to display for a session variable specified by OID
+ *
+ * The result includes all necessary quoting and schema-prefixing.
+ */
+static char *
+generate_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+ char *nspname;
+ char *result;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = NameStr(varform->varname);
+
+ if (!VariableIsVisible(varid))
+ nspname = get_namespace_name_or_temp(varform->varnamespace);
+ else
+ nspname = NULL;
+
+ result = quote_qualified_identifier(nspname, varname);
+
+ ReleaseSysCache(tup);
+
+ return result;
+}
+
/*
* Given a C string, produce a TEXT datum.
*
diff --git a/src/backend/utils/cache/plancache.c b/src/backend/utils/cache/plancache.c
index 6c2979d5c82..88574766861 100644
--- a/src/backend/utils/cache/plancache.c
+++ b/src/backend/utils/cache/plancache.c
@@ -58,6 +58,7 @@
#include "access/transam.h"
#include "catalog/namespace.h"
+#include "catalog/pg_variable.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
@@ -163,6 +164,7 @@ InitPlanCache(void)
CacheRegisterSyscacheCallback(AMOPOPID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNSERVEROID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNDATAWRAPPEROID, PlanCacheSysCallback, (Datum) 0);
+ CacheRegisterSyscacheCallback(VARIABLEOID, PlanCacheObjectCallback, (Datum) 0);
}
/*
@@ -2050,17 +2052,32 @@ ScanQueryForLocks(Query *parsetree, bool acquire)
/*
* Recurse into sublink subqueries, too. But we already did the ones in
- * the rtable and cteList.
+ * the rtable and cteList. We need to force a recursive call for session
+ * variables too, to find and lock variables used in the query (see
+ * ScanQueryWalker).
*/
- if (parsetree->hasSubLinks)
+ if (parsetree->hasSubLinks ||
+ parsetree->hasSessionVariables)
{
query_tree_walker(parsetree, ScanQueryWalker, &acquire,
QTW_IGNORE_RC_SUBQUERIES);
}
+
+ /* process session variables */
+ if (OidIsValid(parsetree->resultVariable))
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ }
}
/*
- * Walker to find sublink subqueries for ScanQueryForLocks
+ * Walker to find sublink subqueries or referenced session variables
+ * for ScanQueryForLocks
*/
static bool
ScanQueryWalker(Node *node, bool *acquire)
@@ -2075,6 +2092,20 @@ ScanQueryWalker(Node *node, bool *acquire)
ScanQueryForLocks(castNode(Query, sub->subselect), *acquire);
/* Fall through to process lefthand args of SubLink */
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ }
+ }
/*
* Do NOT recurse into Query nodes, because ScanQueryForLocks already
@@ -2205,7 +2236,9 @@ PlanCacheRelCallback(Datum arg, Oid relid)
/*
* PlanCacheObjectCallback
- * Syscache inval callback function for PROCOID and TYPEOID caches
+ * Syscache inval callback function for TYPEOID, PROCOID, NAMESPACEOID,
+ * OPEROID, AMOPOPID, FOREIGNSERVEROID, FOREIGNDATAWRAPPEROID and
+ * VARIABLEOID caches.
*
* Invalidate all plans mentioning the object with the specified hash value,
* or all plans mentioning any member of this cache if hashvalue == 0.
diff --git a/src/backend/utils/fmgr/fmgr.c b/src/backend/utils/fmgr/fmgr.c
index 782291d9998..093622fbdc4 100644
--- a/src/backend/utils/fmgr/fmgr.c
+++ b/src/backend/utils/fmgr/fmgr.c
@@ -2026,9 +2026,13 @@ get_call_expr_arg_stable(Node *expr, int argnum)
*/
if (IsA(arg, Const))
return true;
- if (IsA(arg, Param) &&
- ((Param *) arg)->paramkind == PARAM_EXTERN)
- return true;
+ if (IsA(arg, Param))
+ {
+ Param *p = (Param *) arg;
+
+ if (p->paramkind == PARAM_EXTERN || p->paramkind == PARAM_VARIABLE)
+ return true;
+ }
return false;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index c6a65bf7fad..de59ebad700 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1228,8 +1228,8 @@ static const char *const sql_commands[] = {
"ABORT", "ALTER", "ANALYZE", "BEGIN", "CALL", "CHECKPOINT", "CLOSE", "CLUSTER",
"COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE",
"DELETE FROM", "DISCARD", "DO", "DROP", "END", "EXECUTE", "EXPLAIN",
- "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LISTEN", "LOAD", "LOCK",
- "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
+ "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LET",
+ "LISTEN", "LOAD", "LOCK", "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
"REASSIGN", "REFRESH MATERIALIZED VIEW", "REINDEX", "RELEASE",
"RESET", "REVOKE", "ROLLBACK",
"SAVEPOINT", "SECURITY LABEL", "SELECT", "SET", "SHOW", "START",
@@ -4689,6 +4689,14 @@ match_previous_words(int pattern_id,
else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES"))
COMPLETE_WITH("(");
+/* LET */
+ /* If prev. word is LET suggest a list of variables */
+ else if (Matches("LET"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ /* Complete LET <variable> with "=" */
+ else if (TailMatches("LET", MatchAny))
+ COMPLETE_WITH("=");
+
/* LOCK */
/* Complete LOCK [TABLE] [ONLY] with a list of tables */
else if (Matches("LOCK"))
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index bdac0c13bec..5060b8c9490 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -174,6 +174,7 @@ extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
extern List *NamesFromList(List *names);
extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+extern Oid IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror);
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 3d3c6eb24b5..5b45be5afaf 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -18,6 +18,7 @@
#ifndef PG_VARIABLE_H
#define PG_VARIABLE_H
+#include "access/xlogdefs.h"
#include "catalog/genbki.h"
#include "catalog/objectaddress.h"
#include "catalog/pg_variable_d.h"
@@ -35,6 +36,14 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* OID of entry in pg_type for variable's type */
Oid vartype BKI_LOOKUP(pg_type);
+ /*
+ * Used for identity check [oid, create_lsn].
+ *
+ * This column of the 8-byte XlogRecPtr type should be at an address that
+ * is divisible by 8, but before any column of type NameData.
+ */
+ XLogRecPtr varcreate_lsn;
+
/* variable name */
NameData varname;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
new file mode 100644
index 00000000000..2391b9ad443
--- /dev/null
+++ b/src/include/commands/session_variable.h
@@ -0,0 +1,30 @@
+/*-------------------------------------------------------------------------
+ *
+ * sessionvariable.h
+ * prototypes for sessionvariable.c.
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/commands/session_variable.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SESSIONVARIABLE_H
+#define SESSIONVARIABLE_H
+
+#include "nodes/params.h"
+#include "nodes/parsenodes.h"
+#include "parser/parse_node.h"
+#include "tcop/cmdtag.h"
+#include "utils/queryenvironment.h"
+
+extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
+extern Datum GetSessionVariable(Oid varid, bool *isNull);
+
+extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
+ QueryEnvironment *queryEnv, QueryCompletion *qc);
+
+#endif
diff --git a/src/include/executor/svariableReceiver.h b/src/include/executor/svariableReceiver.h
new file mode 100644
index 00000000000..db44d8b94c6
--- /dev/null
+++ b/src/include/executor/svariableReceiver.h
@@ -0,0 +1,22 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.h
+ * prototypes for svariableReceiver.c
+ *
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/executor/svariableReceiver.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SVARIABLE_RECEIVER_H
+#define SVARIABLE_RECEIVER_H
+
+#include "tcop/dest.h"
+
+extern DestReceiver *CreateVariableDestReceiver(Oid varid);
+
+#endif /* SVARIABLE_RECEIVER_H */
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index a323fa98bbb..1b8ad640922 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -636,6 +636,16 @@ typedef struct AsyncRequest
* tuples) */
} AsyncRequest;
+/* ----------------
+ * SessionVariableValue
+ * ----------------
+ */
+typedef struct SessionVariableValue
+{
+ bool isnull;
+ Datum value;
+} SessionVariableValue;
+
/* ----------------
* EState information
*
@@ -696,6 +706,10 @@ typedef struct EState
ParamListInfo es_param_list_info; /* values of external params */
ParamExecData *es_param_exec_vals; /* values of internal params */
+ /* Session variables info: */
+ int es_num_session_variables; /* number of used variables */
+ SessionVariableValue *es_session_variables; /* array of copies of values */
+
QueryEnvironment *es_queryEnv; /* query environment */
/* Other working state: */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 9858034ccf6..40f04098104 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -142,6 +142,9 @@ typedef struct Query
*/
int resultRelation pg_node_attr(query_jumble_ignore);
+ /* target variable of LET statement */
+ Oid resultVariable;
+
/* has aggregates in tlist or havingQual */
bool hasAggs pg_node_attr(query_jumble_ignore);
/* has window functions in tlist */
@@ -162,6 +165,8 @@ typedef struct Query
bool hasRowSecurity pg_node_attr(query_jumble_ignore);
/* parser has added an RTE_GROUP RTE */
bool hasGroupRTE pg_node_attr(query_jumble_ignore);
+ /* uses session variables */
+ bool hasSessionVariables pg_node_attr(query_jumble_ignore);
/* is a RETURN statement */
bool isReturn pg_node_attr(query_jumble_ignore);
@@ -2144,6 +2149,18 @@ typedef struct MergeStmt
ParseLoc stmt_len; /* length in bytes; 0 means "rest of string" */
} MergeStmt;
+/* ----------------------
+ * Let Statement
+ * ----------------------
+ */
+typedef struct LetStmt
+{
+ NodeTag type;
+ List *target; /* target variable */
+ Node *query; /* source expression */
+ ParseLoc location;
+} LetStmt;
+
/* ----------------------
* Select Statement
*
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index fbf05322c75..b4988396a1c 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -179,6 +179,18 @@ typedef struct PlannerGlobal
/* partition descriptors */
PartitionDirectory partition_directory pg_node_attr(read_write_ignore);
+
+ /* list of used session variables */
+ List *sessionVariables;
+
+ /* Oid of session variable used like target of LET command */
+ Oid resultVariable;
+
+ /* oid of session variable used like base node for assignment indirection */
+ Oid basenodeSessionVarid;
+
+ /* true, if we do SELECT permission check on basenodeSessionVarid */
+ bool basenodeSessionVarSelectCheck;
} PlannerGlobal;
/* macro for fetching the Plan associated with a SubPlan node */
@@ -529,6 +541,8 @@ struct PlannerInfo
bool placeholdersFrozen;
/* true if planning a recursive WITH item */
bool hasRecursion;
+ /* true if session variables were used */
+ bool hasSessionVariables;
/*
* The rangetable index for the RTE_GROUP RTE, or 0 if there is no
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index bf1f25c0dba..1f739dc6140 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -128,6 +128,15 @@ typedef struct PlannedStmt
/* non-null if this is utility stmt */
Node *utilityStmt;
+ List *sessionVariables; /* OIDs for PARAM_VARIABLE Params */
+
+ /*
+ * The oid of session variable execluded from permission check.
+ * This session variable is used as base node of assignment indirection
+ * (and it is used only there).
+ */
+ int exclSelectPermCheckVarid;
+
/* statement location in source string (copied from Query) */
/* start location, or -1 if unknown */
ParseLoc stmt_location;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 839e71d52f4..2fa9b1bcd04 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -378,6 +378,9 @@ typedef struct Const
* of the `paramid' field contain the SubLink's subLinkId, and
* the low-order 16 bits contain the column number. (This type
* of Param is also converted to PARAM_EXEC during planning.)
+ *
+ * PARAM_VARIABLE: The parameter is a reference to a session variable
+ * (paramvarid holds the variable's OID).
*/
typedef enum ParamKind
{
@@ -385,6 +388,7 @@ typedef enum ParamKind
PARAM_EXEC,
PARAM_SUBLINK,
PARAM_MULTIEXPR,
+ PARAM_VARIABLE,
} ParamKind;
typedef struct Param
@@ -397,6 +401,16 @@ typedef struct Param
int32 paramtypmod pg_node_attr(query_jumble_ignore);
/* OID of collation, or InvalidOid if none */
Oid paramcollid pg_node_attr(query_jumble_ignore);
+ /* OID of session variable if it is used */
+ Oid paramvarid pg_node_attr(query_jumble_ignore);
+
+ /*
+ * true if param is used as base node of assignment indirection
+ * (when target of LET statement is an array field or an record field).
+ * For this param we do not check SELECT access right, because this
+ * param is used just for execution of UPDATE operation.
+ */
+ bool parambasenode;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index 5a930199611..7a3b522b5ff 100644
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -131,4 +131,6 @@ extern void record_plan_function_dependency(PlannerInfo *root, Oid funcid);
extern void record_plan_type_dependency(PlannerInfo *root, Oid typid);
extern bool extract_query_dependencies_walker(Node *node, PlannerInfo *context);
+extern void pull_up_has_session_variables(PlannerInfo *root);
+
#endif /* PLANMAIN_H */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 793ace526df..431167f6b43 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -257,6 +257,7 @@ PG_KEYWORD("leading", LEADING, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("leakproof", LEAKPROOF, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("least", LEAST, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("left", LEFT, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("let", LET, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("level", LEVEL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("like", LIKE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("limit", LIMIT, RESERVED_KEYWORD, AS_LABEL)
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 994284019fb..0b7b69a4159 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -82,6 +82,8 @@ typedef enum ParseExprKind
EXPR_KIND_COPY_WHERE, /* WHERE condition in COPY FROM */
EXPR_KIND_GENERATED_COLUMN, /* generation expression for a column */
EXPR_KIND_CYCLE_MARK, /* cycle mark value */
+ EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */
+ EXPR_KIND_LET_TARGET, /* LET target */
} ParseExprKind;
@@ -244,6 +246,7 @@ struct ParseState
bool p_hasTargetSRFs;
bool p_hasSubLinks;
bool p_hasModifyingCTE;
+ bool p_hasSessionVariables;
Node *p_last_srf; /* most recent set-returning func/op found */
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index ea86954dded..22082c30008 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -186,6 +186,7 @@ PG_CMDTAG(CMDTAG_GRANT, "GRANT", true, false, false)
PG_CMDTAG(CMDTAG_GRANT_ROLE, "GRANT ROLE", false, false, false)
PG_CMDTAG(CMDTAG_IMPORT_FOREIGN_SCHEMA, "IMPORT FOREIGN SCHEMA", true, false, false)
PG_CMDTAG(CMDTAG_INSERT, "INSERT", false, false, true)
+PG_CMDTAG(CMDTAG_LET, "LET", false, false, false)
PG_CMDTAG(CMDTAG_LISTEN, "LISTEN", false, false, false)
PG_CMDTAG(CMDTAG_LOAD, "LOAD", false, false, false)
PG_CMDTAG(CMDTAG_LOCK_TABLE, "LOCK TABLE", false, false, false)
diff --git a/src/include/tcop/dest.h b/src/include/tcop/dest.h
index 00c092e3d7c..6ce3ea0e617 100644
--- a/src/include/tcop/dest.h
+++ b/src/include/tcop/dest.h
@@ -97,6 +97,7 @@ typedef enum
DestTransientRel, /* results sent to transient relation */
DestTupleQueue, /* results sent to tuple queue */
DestExplainSerialize, /* results are serialized and discarded */
+ DestVariable, /* results sent to session variable */
} CommandDest;
/* ----------------
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index d4377ceecbf..cb282404c1a 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8264,7 +8264,8 @@ exec_is_simple_query(PLpgSQL_expr *expr)
query->sortClause ||
query->limitOffset ||
query->limitCount ||
- query->setOperations)
+ query->setOperations ||
+ query->hasSessionVariables)
return false;
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index c36660ce6d3..f22467186e3 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -431,3 +431,1235 @@ DROP VARIABLE public.var1;
DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+-- check access rights
+CREATE ROLE regress_noowner;
+CREATE VARIABLE var1 AS int;
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+-- should fail
+SET ROLE TO regress_noowner;
+SELECT var1;
+ERROR: permission denied for session variable var1
+SELECT sqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: SQL function "sqlfx" statement 1
+SELECT plpgsqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "$1 + var1"
+PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
+-- should be ok
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+-- should be ok
+SET ROLE TO regress_noowner;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+DROP ROLE regress_noowner;
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- start a new session
+\c
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- should fail, dependency
+DROP VARIABLE var1;
+ERROR: cannot drop session variable var1 because other objects depend on it
+DETAIL: view test_view depends on session variable var1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+NOTICE: drop cascades to view test_view
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+LET var1 = 'str1';
+LET var2 = 'str2';
+SELECT sqlfx1(sqlfx2('Hello'));
+ sqlfx1
+-------------------
+ str1, str2, Hello
+(1 row)
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+ QUERY PLAN
+------------------------------------------------------
+ Result
+ Output: sqlfx1(sqlfx2('Hello'::character varying))
+(2 rows)
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+SET plan_cache_mode TO force_generic_plan;
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 3.14
+(1 row)
+
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 6.28
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 9.42
+(1 row)
+
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 12.56
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+ERROR: function plpgsqlfx2() does not exist
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+SET plan_cache_mode TO DEFAULT;
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 1
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 55
+DROP VARIABLE var1;
+DROP TABLE testvar;
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+NOTICE: result array: {1,2,3,4,5,6,7,8,9,10}
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+-- should not crash (but is not supported yet)
+CALL p(v);
+ERROR: session variable cannot be used as an argument
+DO $$ BEGIN CALL p(v); END $$;
+ERROR: session variable cannot be used as an argument
+CONTEXT: SQL statement "CALL p(v)"
+PL/pgSQL function inline_code_block line 1 at CALL
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+-- should fail
+EXECUTE ptest(v);
+ERROR: session variable cannot be used as an argument
+DEALLOCATE ptest;
+DROP VARIABLE v;
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+-- should fail
+LET var1 = pi();
+ERROR: session variable "var1" doesn't exist
+LINE 1: LET var1 = pi();
+ ^
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+ var1
+------------------
+ 3.14159265358979
+(1 row)
+
+SET search_path TO svartest;
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+ var1
+------------------
+ 13.1415926535898
+(1 row)
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to session variable svartest.var1
+CREATE VARIABLE var1 AS text;
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+SELECT var1;
+ var1
+-------
+ hello
+(1 row)
+
+DROP VARIABLE var1;
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+-- should fail
+SELECT var1;
+ERROR: domain int_domain does not allow null values
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+ var1
+------
+ 1000
+(1 row)
+
+-- should fail
+LET var1 = 10;
+ERROR: value for domain int_domain violates check constraint "int_domain_check"
+-- should fail
+LET var1 = NULL;
+ERROR: domain int_domain does not allow null values
+-- note - domain defaults are not supported yet (like PLpgSQL)
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+ var1
+----------------------------------------
+ {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+(1 row)
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+DROP VARIABLE var1;
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+ var1
+------
+ 100
+(1 row)
+
+SET search_path to public, svartest;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table foo
+drop cascades to session variable var1
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+LET var2[var1] = 0;
+SELECT var2;
+ var2
+-----------
+ [2:2]={0}
+(1 row)
+
+DROP VARIABLE var1, var2;
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+SELECT var2;
+ var2
+------
+ {}
+(1 row)
+
+DROP VARIABLE var1, var2;
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+ERROR: syntax error at or near "LET"
+LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x;
+ ^
+-- should be ok
+LET var1 = generate_series(1, 1);
+-- should fail
+LET var1 = generate_series(1, 2);
+ERROR: expression returned more than one row
+LET var1 = generate_series(1, 0);
+ERROR: expression returned no rows
+DROP VARIABLE var1;
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+SELECT v1;
+ v1
+------------
+ (1,2,3.00)
+(1 row)
+
+SELECT v2;
+ v2
+---------------
+ (10,20,31.40)
+(1 row)
+
+SELECT (v1).*;
+ x | y | z
+---+---+------
+ 1 | 2 | 3.00
+(1 row)
+
+SELECT (v2).*;
+ x | y | z
+----+----+-------
+ 10 | 20 | 31.40
+(1 row)
+
+SELECT v1.x + v1.z;
+ ?column?
+----------
+ 4.00
+(1 row)
+
+SELECT v2.x + v2.z;
+ ?column?
+----------
+ 41.40
+(1 row)
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail
+SELECT v2.x;
+ERROR: permission denied for session variable v2
+SET ROLE TO DEFAULT;
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+ERROR: improper qualified name (too many dotted names): nodb.noschema.novar.nofield.nosubfield
+LET nodb.noschema.novar.nofield = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar.nofield
+LET nodb.noschema.novar = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar
+CREATE TYPE t1 AS (a int, b numeric, c text);
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+ v1
+----------------------------
+ (1,3.14159265358979,hello)
+(1 row)
+
+LET v1.b = 10.2222;
+SELECT v1;
+ v1
+-------------------
+ (1,10.2222,hello)
+(1 row)
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1
+LINE 1: LET v1.x = 10;
+ ^
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+ERROR: assignment expression returned 3 columns
+LINE 1: LET v1 = (NULL::t1).*;
+ ^
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+ v1
+-------------
+ (1,10.2222)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+ v1
+--------------
+ (1,10.2222,)
+(1 row)
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+ v1
+--------------
+ (10,10.3,20)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+ v1
+---------
+ (10,20)
+(1 row)
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+ERROR: cannot alter type "t1" because session variable "public.v1" uses it
+DROP VARIABLE v1;
+DROP TYPE t1;
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+ var1
+----------------------------------
+ (10,3.14159265358979,05-26-2023)
+(1 row)
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+ERROR: cannot alter table "svar_test" because session variable "public.var1" uses it
+-- should fail
+DROP TABLE svar_test;
+ERROR: cannot drop table svar_test because other objects depend on it
+DETAIL: session variable var1 depends on type svar_test
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+CREATE ROLE regress_var_test_role;
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+-- should fail
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+SELECT var1.a;
+ a
+------
+ 1000
+(1 row)
+
+SELECT var1;
+ var1
+------------
+ (1000,100)
+(1 row)
+
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+NOTICE: (0,100)
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+NOTICE: 0
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail again
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+-- should fail
+SELECT var1.a;
+ERROR: variable "public.var1" is of type "text", which is not a composite type
+LINE 1: SELECT var1.a;
+ ^
+SELECT var2.c;
+ERROR: could not identify column "c" in variable "public.var2"
+LINE 1: SELECT var2.c;
+ ^
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+-- should fail
+LET var1 = '1'::jsonb;
+ERROR: variable "public.var1" is of type integer, but expression is of type jsonb
+LINE 1: LET var1 = '1'::jsonb;
+ ^
+HINT: You will need to rewrite or cast the expression.
+-- should be ok
+LET var1 = '1'::jsonb::int;
+-- should fail
+LET var1.x = 10;
+ERROR: cannot assign to field "x" of session variable "public.var1" because its type integer is not a composite type
+LINE 1: LET var1.x = 10;
+ ^
+DROP VARIABLE var1;
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+-- should fail
+LET vartest.vartest = 1;
+ERROR: target "vartest.vartest" of LET command is ambiguous
+LINE 1: LET vartest.vartest = 1;
+ ^
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+ERROR: type "vartesttype" does not exist
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+ var1
+------------
+ {10.1,2.1}
+(1 row)
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+ERROR: set-returning functions are not allowed in LET
+LINE 1: LET var1[generate_series(1,3)] = 100;
+ ^
+DROP VARIABLE var1;
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+ var1
+--------------------
+ (10.2,"{0.0,0.0}")
+(1 row)
+
+LET var1.b[1] = 10.3;
+SELECT var1;
+ var1
+---------------------
+ (10.2,"{10.3,0.0}")
+(1 row)
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ count
+-------
+ 100
+(1 row)
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ QUERY PLAN
+-----------------------------------
+ Aggregate
+ -> Seq Scan on svar_test
+ Filter: ((a % 10) = zero)
+(3 rows)
+
+LET zero = (SELECT count(*) FROM svar_test);
+-- result should be 1000
+SELECT zero;
+ zero
+------
+ 1000
+(1 row)
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO on;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO off;
+DROP VIEW var1view;
+DROP VARIABLE var1;
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 100
+(1 row)
+
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 200
+(1 row)
+
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+---
+(0 rows)
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+ relname
+----------
+ pg_class
+(1 row)
+
+DROP VARIABLE var1;
+CREATE TABLE xxtab(avar int);
+INSERT INTO xxtab VALUES(333);
+CREATE TYPE xxtype AS (avar int);
+CREATE VARIABLE xxtab AS xxtype;
+INSERT INTO xxtab VALUES(10);
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+CREATE VARIABLE public.avar AS int;
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+ avar
+------
+
+
+(2 rows)
+
+DROP VARIABLE xxtab;
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+DROP VARIABLE public.avar;
+DROP TYPE xxtype;
+DROP TABLE xxtab;
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+CREATE TABLE public.svar(a int, b int);
+INSERT INTO public.svar VALUES(10, 20);
+LET public.svar = (100, 200, 300);
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT var1.* FROM vartest_foo;
+ ^
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+ a | b
+----+----
+ 10 | 20
+ 30 | 40
+(2 rows)
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT count(var1.*) FROM vartest_foo;
+ ^
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+ count
+-------
+ 2
+(1 row)
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table vartest.vartest_foo
+drop cascades to session variable vartest.var1
+CREATE TYPE ab AS (a integer, b integer);
+CREATE VARIABLE v_ab AS ab;
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+CREATE SCHEMA v_ab;
+CREATE VARIABLE v_ab.a AS integer;
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+SET search_path TO public;
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+-- should be ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+-- should be still ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+ERROR: session variable reference "xxx_am.b" is ambiguous
+LINE 1: SELECT xxx_am.b;
+ ^
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+ b
+----
+ 10
+(1 row)
+
+SELECT :"DBNAME".xxx_am.b;
+ b
+----
+ 20
+(1 row)
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+ b
+----
+ 10
+(1 row)
+
+SELECT x.b FROM xxx_am x;
+ b
+----
+ 10
+(1 row)
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+CREATE SCHEMA :"DBNAME";
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+SET search_path TO :"DBNAME";
+-- should be ambiguous
+SELECT :"DBNAME".b;
+ERROR: session variable reference "regression.b" is ambiguous
+LINE 1: SELECT "regression".b;
+ ^
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+ERROR: session variable reference "regression.regression.b" is ambiguous
+LINE 1: SELECT "regression"."regression".b;
+ ^
+CREATE TABLE :"DBNAME"(b int);
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+ b
+---
+(0 rows)
+
+DROP TABLE :"DBNAME";
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+RESET search_path;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index eeb0f94ca3c..e72360d5254 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -295,3 +295,886 @@ DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+
+-- check access rights
+CREATE ROLE regress_noowner;
+
+CREATE VARIABLE var1 AS int;
+
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+SELECT sqlfx(20);
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx(20);
+SELECT plpgsqlfx_sd(20);
+
+-- should fail
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+-- should be ok
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx_sd(20);
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+
+-- should be ok
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+
+DROP ROLE regress_noowner;
+
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- start a new session
+\c
+
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- should fail, dependency
+DROP VARIABLE var1;
+
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+
+LET var1 = 'str1';
+LET var2 = 'str2';
+
+SELECT sqlfx1(sqlfx2('Hello'));
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+
+SET plan_cache_mode TO force_generic_plan;
+
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+
+SET plan_cache_mode TO DEFAULT;
+
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP TABLE testvar;
+
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+
+-- should not crash (but is not supported yet)
+CALL p(v);
+
+DO $$ BEGIN CALL p(v); END $$;
+
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+
+-- should fail
+EXECUTE ptest(v);
+
+DEALLOCATE ptest;
+DROP VARIABLE v;
+
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+
+-- should fail
+LET var1 = pi();
+SELECT var1;
+
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+
+SET search_path TO svartest;
+
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS text;
+
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+
+-- should fail
+SELECT var1;
+
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+
+-- should fail
+LET var1 = 10;
+
+-- should fail
+LET var1 = NULL;
+
+-- note - domain defaults are not supported yet (like PLpgSQL)
+
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+
+SET search_path to public, svartest;
+
+SELECT var1;
+
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+LET var2[var1] = 0;
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+
+-- should be ok
+LET var1 = generate_series(1, 1);
+
+-- should fail
+LET var1 = generate_series(1, 2);
+LET var1 = generate_series(1, 0);
+
+DROP VARIABLE var1;
+
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+
+SELECT v1;
+SELECT v2;
+SELECT (v1).*;
+SELECT (v2).*;
+
+SELECT v1.x + v1.z;
+SELECT v2.x + v2.z;
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should fail
+SELECT v2.x;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+LET nodb.noschema.novar.nofield = 10;
+LET nodb.noschema.novar = 10;
+
+CREATE TYPE t1 AS (a int, b numeric, c text);
+
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+LET v1.b = 10.2222;
+SELECT v1;
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+
+DROP VARIABLE v1;
+DROP TYPE t1;
+
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+
+-- should fail
+DROP TABLE svar_test;
+
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+
+CREATE ROLE regress_var_test_role;
+
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+
+-- should fail
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should fail again
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+
+-- should fail
+SELECT var1.a;
+SELECT var2.c;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+
+CREATE VARIABLE var1 AS int;
+
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+
+-- should fail
+LET var1 = '1'::jsonb;
+
+-- should be ok
+LET var1 = '1'::jsonb::int;
+
+-- should fail
+LET var1.x = 10;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+
+-- should fail
+LET vartest.vartest = 1;
+
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+
+DROP VARIABLE var1;
+
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+LET var1.b[1] = 10.3;
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+LET zero = (SELECT count(*) FROM svar_test);
+
+-- result should be 1000
+SELECT zero;
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO on;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO off;
+
+DROP VIEW var1view;
+DROP VARIABLE var1;
+
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+
+DROP VARIABLE var1;
+
+CREATE TABLE xxtab(avar int);
+
+INSERT INTO xxtab VALUES(333);
+
+CREATE TYPE xxtype AS (avar int);
+
+CREATE VARIABLE xxtab AS xxtype;
+
+INSERT INTO xxtab VALUES(10);
+
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+
+-- should be ok
+SELECT avar FROM xxtab;
+
+CREATE VARIABLE public.avar AS int;
+
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+
+DROP VARIABLE xxtab;
+
+SELECT xxtab.avar FROM xxtab;
+
+DROP VARIABLE public.avar;
+
+DROP TYPE xxtype;
+
+DROP TABLE xxtab;
+
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+
+CREATE TABLE public.svar(a int, b int);
+
+INSERT INTO public.svar VALUES(10, 20);
+
+LET public.svar = (100, 200, 300);
+
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+
+CREATE TYPE ab AS (a integer, b integer);
+
+CREATE VARIABLE v_ab AS ab;
+
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+CREATE SCHEMA v_ab;
+
+CREATE VARIABLE v_ab.a AS integer;
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+
+SET search_path TO public;
+
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+
+-- should be ok
+SELECT xxx_am;
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+
+-- should be still ok
+SELECT xxx_am;
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+SELECT :"DBNAME".xxx_am.b;
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+SELECT x.b FROM xxx_am x;
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+
+CREATE SCHEMA :"DBNAME";
+
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+
+SET search_path TO :"DBNAME";
+
+-- should be ambiguous
+SELECT :"DBNAME".b;
+
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+
+CREATE TABLE :"DBNAME"(b int);
+
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+
+DROP TABLE :"DBNAME";
+
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+
+RESET search_path;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index cfb92f8e6c8..c42304dd4bb 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1508,6 +1508,7 @@ LargeObjectDesc
Latch
LauncherLastStartTimesEntry
LerpFunc
+LetStmt
LexDescr
LexemeEntry
LexemeHashKey
@@ -2631,6 +2632,7 @@ SerializedTransactionState
Session
SessionBackupState
SessionEndType
+SessionVariableValue
SetConstraintState
SetConstraintStateData
SetConstraintTriggerData
@@ -2826,6 +2828,9 @@ SupportRequestRows
SupportRequestSelectivity
SupportRequestSimplify
SupportRequestWFuncMonotonic
+SVariable
+SVariableData
+SVariableState
Syn
SyncOps
SyncRepConfigData
--
2.48.1
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-03-01 07:23 ` Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Pavel Stehule @ 2025-03-01 07:23 UTC (permalink / raw)
To: jian he <[email protected]>; +Cc: Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
Hi
fix regress tests after 95dbd827f2edc4d10bebd7e840a0bd6782cf69b7
Regards
Pavel
Attachments:
[text/x-patch] v20250301-0003-function-pg_session_variables-for-cleaning-tests.patch (4.3K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/3-v20250301-0003-function-pg_session_variables-for-cleaning-tests.patch)
download | inline diff:
From ef55d6941f58d520b3ab71597ef7da86dcb92f64 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 20:01:56 +0100
Subject: [PATCH 03/21] function pg_session_variables for cleaning tests
This is a function designed for testing and debugging. It returns the
content of sessionvars as-is, and can therefore display entries about
session variables that were dropped but for which this backend didn't
process the shared invalidations yet.
---
src/backend/commands/session_variable.c | 92 +++++++++++++++++++++++++
src/include/catalog/pg_proc.dat | 8 +++
2 files changed, 100 insertions(+)
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index d2891a1dcb7..fa16f47072e 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -527,3 +527,95 @@ ExecuteLetStmt(ParseState *pstate,
PopActiveSnapshot();
}
+
+/*
+ * pg_session_variables - designed for testing
+ *
+ * This is a function designed for testing and debugging. It returns the
+ * content of session variables as-is, and can therefore display data about
+ * session variables that were dropped, but for which this backend didn't
+ * process the shared invalidations yet.
+ */
+Datum
+pg_session_variables(PG_FUNCTION_ARGS)
+{
+#define NUM_PG_SESSION_VARIABLES_ATTS 8
+
+ InitMaterializedSRF(fcinfo, 0);
+
+ if (sessionvars)
+ {
+ ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ Datum values[NUM_PG_SESSION_VARIABLES_ATTS];
+ bool nulls[NUM_PG_SESSION_VARIABLES_ATTS];
+ HeapTuple tp;
+ bool var_is_valid = false;
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, 0, sizeof(nulls));
+
+ values[0] = ObjectIdGetDatum(svar->varid);
+ values[3] = ObjectIdGetDatum(svar->typid);
+
+ /*
+ * It is possible that the variable has been dropped from the
+ * catalog, but not yet purged from the hash table.
+ */
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ Form_pg_variable varform = (Form_pg_variable) GETSTRUCT(tp);
+
+ /*
+ * It is also possible that a variable has been dropped and
+ * someone created a new variable with the same object ID. Use
+ * the catalog information only if that is not the case.
+ */
+ if (svar->create_lsn == varform->varcreate_lsn)
+ {
+ values[1] = CStringGetTextDatum(
+ get_namespace_name(varform->varnamespace));
+
+ values[2] = CStringGetTextDatum(NameStr(varform->varname));
+ values[4] = CStringGetTextDatum(format_type_be(svar->typid));
+ values[5] = BoolGetDatum(false);
+
+ values[6] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_SELECT) == ACLCHECK_OK);
+
+ values[7] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_UPDATE) == ACLCHECK_OK);
+
+ var_is_valid = true;
+ }
+
+ ReleaseSysCache(tp);
+ }
+
+ /* if there is no matching catalog entry, return null values */
+ if (!var_is_valid)
+ {
+ nulls[1] = true;
+ nulls[2] = true;
+ nulls[4] = true;
+ values[5] = BoolGetDatum(true);
+ nulls[6] = true;
+ nulls[7] = true;
+ }
+
+ tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
+ }
+ }
+
+ return (Datum) 0;
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 2b06d9475b5..664cc83436f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -12473,4 +12473,12 @@
proargtypes => 'int4',
prosrc => 'gist_stratnum_common' },
+# Session variables support
+{ oid => '8488', descr => 'list of used session variables',
+ proname => 'pg_session_variables', prorows => '1000', proretset => 't',
+ provolatile => 's', proparallel => 'r', prorettype => 'record',
+ proargtypes => '', proallargtypes => '{oid,text,text,oid,text,bool,bool,bool}',
+ proargmodes => '{o,o,o,o,o,o,o,o}',
+ proargnames => '{varid,schema,name,typid,typname,removed,can_select,can_update}',
+ prosrc => 'pg_session_variables' },
]
--
2.48.1
[text/x-patch] v20250301-0001-Enhancing-catalog-for-support-session-variables-and-.patch (169.3K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/4-v20250301-0001-Enhancing-catalog-for-support-session-variables-and-.patch)
download | inline diff:
From 4129b32c60225220f68a56a627c85643682a42da Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 15:41:55 +0100
Subject: [PATCH 01/21] Enhancing catalog for support session variables and
related support
This patch introduces new system catalog table pg_variable. This table holds metadata about
session variables created by command CREATE VARIABLE, and dropped by command DROP VARIABLE.
Both commands are implemented by this patch. Possibility to change owner, schema or rename.
Access to session variables can be controlled by SELECT or UPDATE rights. Both rights are
introduced by this patch too.
This patch enhancing pg_dump and psql to support session variables. The changes are related
to system catalog.
This patch is not short, but the code is simple.
---
doc/src/sgml/catalogs.sgml | 123 ++++-
doc/src/sgml/ddl.sgml | 40 +-
doc/src/sgml/func.sgml | 32 ++
doc/src/sgml/glossary.sgml | 15 +
doc/src/sgml/ref/allfiles.sgml | 3 +
.../sgml/ref/alter_default_privileges.sgml | 27 +-
doc/src/sgml/ref/alter_variable.sgml | 178 +++++++
doc/src/sgml/ref/comment.sgml | 1 +
doc/src/sgml/ref/create_schema.sgml | 12 +-
doc/src/sgml/ref/create_variable.sgml | 149 ++++++
doc/src/sgml/ref/drop_variable.sgml | 117 +++++
doc/src/sgml/ref/grant.sgml | 20 +-
doc/src/sgml/ref/psql-ref.sgml | 13 +
doc/src/sgml/ref/revoke.sgml | 8 +
doc/src/sgml/reference.sgml | 3 +
src/backend/catalog/Makefile | 1 +
src/backend/catalog/aclchk.c | 77 ++++
src/backend/catalog/dependency.c | 6 +
src/backend/catalog/meson.build | 1 +
src/backend/catalog/namespace.c | 221 +++++++++
src/backend/catalog/objectaddress.c | 121 ++++-
src/backend/catalog/pg_shdepend.c | 2 +
src/backend/catalog/pg_variable.c | 251 ++++++++++
src/backend/commands/alter.c | 9 +
src/backend/commands/dropcmds.c | 4 +
src/backend/commands/event_trigger.c | 4 +
src/backend/commands/seclabel.c | 1 +
src/backend/commands/tablecmds.c | 41 ++
src/backend/commands/typecmds.c | 15 +
src/backend/parser/gram.y | 105 ++++-
src/backend/parser/parse_utilcmd.c | 12 +
src/backend/tcop/utility.c | 20 +
src/backend/utils/adt/acl.c | 221 +++++++++
src/backend/utils/cache/lsyscache.c | 113 +++++
src/bin/pg_dump/common.c | 3 +
src/bin/pg_dump/dumputils.c | 6 +
src/bin/pg_dump/pg_backup.h | 2 +
src/bin/pg_dump/pg_backup_archiver.c | 9 +
src/bin/pg_dump/pg_dump.c | 190 ++++++++
src/bin/pg_dump/pg_dump.h | 15 +
src/bin/pg_dump/pg_dump_sort.c | 7 +
src/bin/pg_dump/t/002_pg_dump.pl | 64 +++
src/bin/psql/command.c | 3 +
src/bin/psql/describe.c | 100 +++-
src/bin/psql/describe.h | 3 +
src/bin/psql/help.c | 1 +
src/bin/psql/tab-complete.in.c | 43 +-
src/include/catalog/Makefile | 3 +-
src/include/catalog/meson.build | 1 +
src/include/catalog/namespace.h | 6 +
src/include/catalog/pg_default_acl.h | 1 +
src/include/catalog/pg_proc.dat | 23 +
src/include/catalog/pg_variable.h | 81 ++++
src/include/nodes/parsenodes.h | 16 +
src/include/parser/kwlist.h | 2 +
src/include/tcop/cmdtaglist.h | 3 +
src/include/utils/acl.h | 1 +
src/include/utils/lsyscache.h | 9 +
src/test/regress/expected/dependency.out | 17 +
src/test/regress/expected/oidjoins.out | 4 +
src/test/regress/expected/psql.out | 50 ++
.../regress/expected/session_variables.out | 433 ++++++++++++++++++
src/test/regress/parallel_schedule | 2 +-
src/test/regress/sql/dependency.sql | 14 +
src/test/regress/sql/psql.sql | 21 +
src/test/regress/sql/session_variables.sql | 297 ++++++++++++
src/tools/pgindent/typedefs.list | 4 +
67 files changed, 3364 insertions(+), 36 deletions(-)
create mode 100644 doc/src/sgml/ref/alter_variable.sgml
create mode 100644 doc/src/sgml/ref/create_variable.sgml
create mode 100644 doc/src/sgml/ref/drop_variable.sgml
create mode 100644 src/backend/catalog/pg_variable.c
create mode 100644 src/include/catalog/pg_variable.h
create mode 100644 src/test/regress/expected/session_variables.out
create mode 100644 src/test/regress/sql/session_variables.sql
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index ee59a7e15d0..7ba91b1f4b1 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -369,6 +369,11 @@
<entry><link linkend="catalog-pg-user-mapping"><structname>pg_user_mapping</structname></link></entry>
<entry>mappings of users to foreign servers</entry>
</row>
+
+ <row>
+ <entry><link linkend="catalog-pg-variable"><structname>pg_variable</structname></link></entry>
+ <entry>session variables</entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -3340,7 +3345,8 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
<literal>S</literal> = sequence,
<literal>f</literal> = function,
<literal>T</literal> = type,
- <literal>n</literal> = schema
+ <literal>n</literal> = schema,
+ <literal>V</literal> = session variable
</para></entry>
</row>
@@ -9758,4 +9764,119 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</table>
</sect1>
+ <sect1 id="catalog-pg-variable">
+ <title><structname>pg_variable</structname></title>
+
+ <indexterm zone="catalog-pg-variable">
+ <primary>pg_variable</primary>
+ </indexterm>
+
+ <para>
+ The catalog <structname>pg_variable</structname> stores information about
+ session variables.
+ </para>
+
+ <table>
+ <title><structname>pg_variable</structname> Columns</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ Column Type
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>oid</structfield> <type>oid</type>
+ </para>
+ <para>
+ Row identifier
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartype</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-type"><structname>pg_type</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the variable's data type
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varname</structfield> <type>name</type>
+ </para>
+ <para>
+ Name of the session variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varnamespace</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the namespace that contains this variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varowner</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ Owner of the variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartypmod</structfield> <type>int4</type>
+ </para>
+ <para>
+ <structfield>vartypmod</structfield> records type-specific data
+ supplied at variable creation time (for example, the maximum
+ length of a <type>varchar</type> column). It is passed to
+ type-specific input functions and length coercion functions.
+ The value will generally be -1 for types that do not need <structfield>vartypmod</structfield>.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcollation</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-collation"><structname>pg_collation</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The defined collation of the variable, or zero if the variable is
+ not of a collatable data type.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varacl</structfield> <type>aclitem[]</type>
+ </para>
+ <para>
+ Access privileges; see
+ <xref linkend="sql-grant"/> and
+ <xref linkend="sql-revoke"/>
+ for details
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+ </sect1>
</chapter>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index ae156b6b1cd..edfb7db24fc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -2020,6 +2020,7 @@ REVOKE ALL ON accounts FROM PUBLIC;
For sequences, this privilege also allows use of the
<function>currval</function> function.
For large objects, this privilege allows the object to be read.
+ For session variables, this privilege allows the object to be read.
</para>
</listitem>
</varlistentry>
@@ -2055,6 +2056,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<function>setval</function> functions.
For large objects, this privilege allows writing or truncating the
object.
+ For session variables, this privilege allows to set a value to the
+ object.
</para>
</listitem>
</varlistentry>
@@ -2298,7 +2301,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal> (and table-like objects),
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2313,7 +2317,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal>,
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2500,6 +2505,12 @@ REVOKE ALL ON accounts FROM PUBLIC;
<entry><literal>U</literal></entry>
<entry><literal>\dT+</literal></entry>
</row>
+ <row>
+ <entry><literal>SESSION VARIABLE</literal></entry>
+ <entry><literal>rw</literal></entry>
+ <entry><literal>none</literal></entry>
+ <entry><literal>\dV+</literal></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -5350,6 +5361,31 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
</para>
</sect1>
+ <sect1 id="ddl-session-variables">
+ <title>Session Variables</title>
+
+ <indexterm zone="ddl-session-variables">
+ <primary>Session variables</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ </indexterm>
+
+ <para>
+ Session variables are database objects that can hold a value.
+ Session variables, like relations, exist within a schema and their access
+ is controlled via <command>GRANT</command> and <command>REVOKE</command>
+ commands. A session variable can be created by the <command>CREATE
+ VARIABLE</command> command.
+ </para>
+
+ <para>
+ The session variable holds value in session memory. This value is private
+ to each session and is released when the session ends.
+ </para>
+ </sect1>
+
<sect1 id="ddl-others">
<title>Other Database Objects</title>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 0e6c5349652..1663b5339ba 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25342,6 +25342,25 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
</para></entry>
</row>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>has_session_variable_privilege</primary>
+ </indexterm>
+ <function>has_session_variable_privilege</function> (
+ <optional> <parameter>user</parameter> <type>name</type> or <type>oid</type>, </optional>
+ <parameter>session_variable</parameter> <type>text</type> or <type>oid</type>,
+ <parameter>privilege</parameter> <type>text</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Does user have privilege for session variable?
+ Allowable privilege types are
+ <literal>SELECT</literal>, and
+ <literal>UPDATE</literal>.
+ </para></entry>
+ </row>
+
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
@@ -25850,6 +25869,19 @@ SELECT relname FROM pg_class WHERE pg_table_is_visible(oid);
Is type (or domain) visible in search path?
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_variable_is_visible</primary>
+ </indexterm>
+ <function>pg_variable_is_visible</function> ( <parameter>variable</parameter> <type>oid</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Is session variable visible in search path?
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index c0f812e3f5e..b921f5a3339 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1669,6 +1669,21 @@
</glossdef>
</glossentry>
+ <glossentry id="glossary-session-variable">
+ <glossterm>Session variable</glossterm>
+ <glossdef>
+ <para>
+ A persistent database object that holds a value in session memory. This
+ value is private to each session and is released when the session ends.
+ Read or write access to session variables is controlled by privileges,
+ similar to other database objects.
+ </para>
+ <para>
+ For more information, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </glossdef>
+ </glossentry>
+
<glossentry id="glossary-shared-memory">
<glossterm>Shared memory</glossterm>
<glossdef>
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index f5be638867a..2f67de3e21b 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -47,6 +47,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY alterType SYSTEM "alter_type.sgml">
<!ENTITY alterUser SYSTEM "alter_user.sgml">
<!ENTITY alterUserMapping SYSTEM "alter_user_mapping.sgml">
+<!ENTITY alterVariable SYSTEM "alter_variable.sgml">
<!ENTITY alterView SYSTEM "alter_view.sgml">
<!ENTITY analyze SYSTEM "analyze.sgml">
<!ENTITY begin SYSTEM "begin.sgml">
@@ -99,6 +100,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY createType SYSTEM "create_type.sgml">
<!ENTITY createUser SYSTEM "create_user.sgml">
<!ENTITY createUserMapping SYSTEM "create_user_mapping.sgml">
+<!ENTITY createVariable SYSTEM "create_variable.sgml">
<!ENTITY createView SYSTEM "create_view.sgml">
<!ENTITY deallocate SYSTEM "deallocate.sgml">
<!ENTITY declare SYSTEM "declare.sgml">
@@ -147,6 +149,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY dropType SYSTEM "drop_type.sgml">
<!ENTITY dropUser SYSTEM "drop_user.sgml">
<!ENTITY dropUserMapping SYSTEM "drop_user_mapping.sgml">
+<!ENTITY dropVariable SYSTEM "drop_variable.sgml">
<!ENTITY dropView SYSTEM "drop_view.sgml">
<!ENTITY end SYSTEM "end.sgml">
<!ENTITY execute SYSTEM "execute.sgml">
diff --git a/doc/src/sgml/ref/alter_default_privileges.sgml b/doc/src/sgml/ref/alter_default_privileges.sgml
index 89aacec4fab..a5852d32566 100644
--- a/doc/src/sgml/ref/alter_default_privileges.sgml
+++ b/doc/src/sgml/ref/alter_default_privileges.sgml
@@ -51,6 +51,11 @@ GRANT { { USAGE | CREATE }
ON SCHEMAS
TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+GRANT { { SELECT | UPDATE }
+ [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+
REVOKE [ GRANT OPTION FOR ]
{ { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER | MAINTAIN }
[, ...] | ALL [ PRIVILEGES ] }
@@ -83,6 +88,12 @@ REVOKE [ GRANT OPTION FOR ]
ON SCHEMAS
FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
[ CASCADE | RESTRICT ]
+
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
+ [ CASCADE | RESTRICT ]
</synopsis>
</refsynopsisdiv>
@@ -117,14 +128,14 @@ REVOKE [ GRANT OPTION FOR ]
<para>
Currently,
only the privileges for schemas, tables (including views and foreign
- tables), sequences, functions, and types (including domains) can be
- altered. For this command, functions include aggregates and procedures.
- The words <literal>FUNCTIONS</literal> and <literal>ROUTINES</literal> are
- equivalent in this command. (<literal>ROUTINES</literal> is preferred
- going forward as the standard term for functions and procedures taken
- together. In earlier PostgreSQL releases, only the
- word <literal>FUNCTIONS</literal> was allowed. It is not possible to set
- default privileges for functions and procedures separately.)
+ tables), sequences, functions, types (including domains), and session
+ variables can be altered. For this command, functions include aggregates
+ and procedures. The words <literal>FUNCTIONS</literal> and
+ <literal>ROUTINES</literal> are equivalent in this command.
+ (<literal>ROUTINES</literal> is preferred going forward as the standard
+ term for functions and procedures taken together. In earlier PostgreSQL
+ releases, only the word <literal>FUNCTIONS</literal> was allowed. It is not
+ possible to set default privileges for functions and procedures separately.)
</para>
<para>
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
new file mode 100644
index 00000000000..96d2586423e
--- /dev/null
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -0,0 +1,178 @@
+<!--
+doc/src/sgml/ref/alter_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-altervariable">
+ <indexterm zone="sql-altervariable">
+ <primary>ALTER VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>altering</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>ALTER VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>ALTER VARIABLE</refname>
+ <refpurpose>
+ change the definition of a session variable
+ </refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable class="parameter">new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable class="parameter">new_name</replaceable>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> SET SCHEMA <replaceable class="parameter">new_schema</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>ALTER VARIABLE</command> command changes the definition of an
+ existing session variable. There are several subforms:
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>OWNER</literal></term>
+ <listitem>
+ <para>
+ This form changes the owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RENAME</literal></term>
+ <listitem>
+ <para>
+ This form changes the name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>SET SCHEMA</literal></term>
+ <listitem>
+ <para>
+ This form moves the session variable into another schema.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </para>
+
+ <para>
+ Only the owner or a superuser is allowed to alter a session variable.
+ In order to move a session variable from one schema to another, the user
+ must also have the <literal>CREATE</literal> privilege on the new schema (or
+ be a superuser).
+
+ In order to move the session variable ownership from one role to another,
+ the user must also be a direct or indirect member of the new
+ owning role, and that role must have the <literal>CREATE</literal> privilege
+ on the session variable's schema (or be a superuser). These restrictions
+ enforce that altering the owner doesn't do anything you couldn't do by
+ dropping and recreating the session variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <para>
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name (possibly schema-qualified) of the existing session variable
+ to alter.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_owner</replaceable></term>
+ <listitem>
+ <para>
+ The user name of the new owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_name</replaceable></term>
+ <listitem>
+ <para>
+ The new name for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_schema</replaceable></term>
+ <listitem>
+ <para>
+ The new schema for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To rename a session variable:
+<programlisting>
+ALTER VARIABLE foo RENAME TO boo;
+</programlisting>
+ </para>
+
+ <para>
+ To change the owner of the session variable <literal>boo</literal> to
+ <literal>joe</literal>:
+<programlisting>
+ALTER VARIABLE boo OWNER TO joe;
+</programlisting>
+ </para>
+
+ <para>
+ To change the schema of the session variable <literal>boo</literal> to
+ <literal>private</literal>:
+<programlisting>
+ALTER VARIABLE boo SET SCHEMA private;
+</programlisting>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ Session variables and this command in particular are a PostgreSQL extension.
+ </para>
+ </refsect1>
+
+ <refsect1 id="sql-altervariable-see-also">
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index 5b43c56b133..21cd80818fb 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -65,6 +65,7 @@ COMMENT ON
TRANSFORM FOR <replaceable>type_name</replaceable> LANGUAGE <replaceable>lang_name</replaceable> |
TRIGGER <replaceable class="parameter">trigger_name</replaceable> ON <replaceable class="parameter">table_name</replaceable> |
TYPE <replaceable class="parameter">object_name</replaceable> |
+ VARIABLE <replaceable class="parameter">object_name</replaceable> |
VIEW <replaceable class="parameter">object_name</replaceable>
} IS { <replaceable class="parameter">string_literal</replaceable> | NULL }
diff --git a/doc/src/sgml/ref/create_schema.sgml b/doc/src/sgml/ref/create_schema.sgml
index ed69298ccc6..d2bb265209b 100644
--- a/doc/src/sgml/ref/create_schema.sgml
+++ b/doc/src/sgml/ref/create_schema.sgml
@@ -103,9 +103,10 @@ CREATE SCHEMA IF NOT EXISTS AUTHORIZATION <replaceable class="parameter">role_sp
schema. Currently, only <command>CREATE
TABLE</command>, <command>CREATE VIEW</command>, <command>CREATE
INDEX</command>, <command>CREATE SEQUENCE</command>, <command>CREATE
- TRIGGER</command> and <command>GRANT</command> are accepted as clauses
- within <command>CREATE SCHEMA</command>. Other kinds of objects may
- be created in separate commands after the schema is created.
+ TRIGGER</command>, <command>GRANT</command> and <command>CREATE
+ VARIABLE</command> are accepted as clauses within <command>CREATE
+ SCHEMA</command>. Other kinds of objects may be created in separate
+ commands after the schema is created.
</para>
</listitem>
</varlistentry>
@@ -214,6 +215,11 @@ CREATE VIEW hollywood.winners AS
The <literal>IF NOT EXISTS</literal> option is a
<productname>PostgreSQL</productname> extension.
</para>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
</refsect1>
<refsect1>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
new file mode 100644
index 00000000000..6e988f2e472
--- /dev/null
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -0,0 +1,149 @@
+<!--
+doc/src/sgml/ref/create_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-createvariable">
+ <indexterm zone="sql-createvariable">
+ <primary>CREATE VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>defining</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>CREATE VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>CREATE VARIABLE</refname>
+ <refpurpose>define a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+</synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command creates a session variable.
+ Session variables, like relations, exist within a schema and their access is
+ controlled via the commands <command>GRANT</command> and <command>REVOKE</command>.
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a session variable's value returns NULL, unless its value is set to
+ something else in the current session with a <command>LET</command> command.
+ The content of a session variable is not transactional. This is the same as
+ regular variables in procedural languages.
+ </para>
+
+ <para>
+ Session variables are retrieved by the <command>SELECT</command>
+ command. Their value is set with the <command>LET</command> command.
+ </para>
+
+ <note>
+ <para>
+ Session variables can be <quote>shadowed</quote> by other identifiers.
+ For details, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </note>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+
+ <varlistentry id="sql-createvariable-if-not-exists">
+ <term><literal>IF NOT EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the name already exists. A notice is issued in
+ this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-name">
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-data_type">
+ <term><replaceable class="parameter">data_type</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the data type of the session
+ variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-collate">
+ <term><literal>COLLATE <replaceable>collation</replaceable></literal></term>
+ <listitem>
+ <para>
+ The <literal>COLLATE</literal> clause assigns a collation to the session
+ variable (which must be of a collatable data type). If not specified,
+ the data type's default collation is used.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para>
+ Use the <command>DROP VARIABLE</command> command to remove a session
+ variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ Create an date session variable <literal>var1</literal>:
+<programlisting>
+CREATE VARIABLE var1 AS date;
+</programlisting>
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
new file mode 100644
index 00000000000..5bdb3560f0b
--- /dev/null
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -0,0 +1,117 @@
+<!--
+doc/src/sgml/ref/drop_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-dropvariable">
+ <indexterm zone="sql-dropvariable">
+ <primary>DROP VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>removing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>DROP VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>DROP VARIABLE</refname>
+ <refpurpose>remove a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+DROP VARIABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ <command>DROP VARIABLE</command> removes a session variable.
+ A session variable can only be removed by its owner or a superuser.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>IF EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the session variable does not exist. A notice is
+ issued in this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of a session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>CASCADE</literal></term>
+ <listitem>
+ <para>
+ Automatically drop objects that depend on the session variable (such as
+ views), and in turn all objects that depend on those objects
+ (see <xref linkend="ddl-depend"/>).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RESTRICT</literal></term>
+ <listitem>
+ <para>
+ Refuse to drop the session variable if any objects depend on it. This is
+ the default.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To remove the session variable <literal>var1</literal>:
+
+<programlisting>
+DROP VARIABLE var1;
+</programlisting></para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>DROP VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index 999f657d5c0..c11860fa200 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -101,6 +101,12 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
[ WITH { ADMIN | INHERIT | SET } { OPTION | TRUE | FALSE } ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+GRANT { SELECT | UPDATE | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
@@ -119,8 +125,8 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
that grants privileges on a database object (table, column, view,
foreign table, sequence, database, foreign-data wrapper, foreign server,
function, procedure, procedural language, large object, configuration
- parameter, schema, tablespace, or type), and one that grants
- membership in a role. These variants are similar in many ways, but
+ parameter, schema, session variable, tablespace, or type), and one that
+ grants membership in a role. These variants are similar in many ways, but
they are different enough to be described separately.
</para>
@@ -236,9 +242,9 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
<para>
There is also an option to grant privileges on all objects of the same
type within one or more schemas. This functionality is currently supported
- only for tables, sequences, functions, and procedures. <literal>ALL
- TABLES</literal> also affects views and foreign tables, just like the
- specific-object <command>GRANT</command> command. <literal>ALL
+ only for tables, sequences, functions, procedures and variables.
+ <literal>ALL TABLES</literal> also affects views and foreign tables, just
+ like the specific-object <command>GRANT</command> command. <literal>ALL
FUNCTIONS</literal> also affects aggregate and window functions, but not
procedures, again just like the specific-object <command>GRANT</command>
command. Use <literal>ALL ROUTINES</literal> to include procedures.
@@ -518,8 +524,8 @@ GRANT admins TO joe;
</para>
<para>
- Privileges on databases, tablespaces, schemas, languages, and
- configuration parameters are
+ Privileges on databases, tablespaces, schemas, languages, session variables
+ and configuration parameters are
<productname>PostgreSQL</productname> extensions.
</para>
</refsect1>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..83abd7abb69 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -2135,6 +2135,19 @@ SELECT $1 \parse stmt1
</listitem>
</varlistentry>
+ <varlistentry id="app-psql-meta-command-dv">
+ <term><literal>\dV[+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
+ <listitem>
+ <para>
+ Lists session variables.
+ If <replaceable class="parameter">pattern</replaceable> is
+ specified, only session variables whose names match the pattern are listed.
+ If the form <literal>\dV+</literal> is used, additional information
+ about each variable is shown, like access privileges and description.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="app-psql-meta-command-du">
<term><literal>\du[Sx+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
<listitem>
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index 8df492281a1..760fddb7c20 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -130,6 +130,14 @@ REVOKE [ { ADMIN | INHERIT | SET } OPTION FOR ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
[ CASCADE | RESTRICT ]
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ FROM { <replaceable class="parameter">role_specification</replaceable> | PUBLIC } [, ...]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+ [ CASCADE | RESTRICT ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index ff85ace83fc..25578f3946c 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -75,6 +75,7 @@
&alterType;
&alterUser;
&alterUserMapping;
+ &alterVariable;
&alterView;
&analyze;
&begin;
@@ -127,6 +128,7 @@
&createType;
&createUser;
&createUserMapping;
+ &createVariable;
&createView;
&deallocate;
&declare;
@@ -175,6 +177,7 @@
&dropType;
&dropUser;
&dropUserMapping;
+ &dropVariable;
&dropView;
&end;
&execute;
diff --git a/src/backend/catalog/Makefile b/src/backend/catalog/Makefile
index c090094ed08..2c20d60db19 100644
--- a/src/backend/catalog/Makefile
+++ b/src/backend/catalog/Makefile
@@ -45,6 +45,7 @@ OBJS = \
pg_shdepend.o \
pg_subscription.o \
pg_type.o \
+ pg_variable.o \
storage.o \
toasting.o
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 02a754cc30a..1e8ce752b90 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -64,6 +64,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -291,6 +292,9 @@ restrict_and_check_grant(bool is_grant, AclMode avail_goptions, bool all_privs,
case OBJECT_PARAMETER_ACL:
whole_mask = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ whole_mask = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", objtype);
/* not reached, but keep compiler quiet */
@@ -535,6 +539,10 @@ ExecuteGrantStmt(GrantStmt *stmt)
all_privileges = ACL_ALL_RIGHTS_PARAMETER_ACL;
errormsg = gettext_noop("invalid privilege type %s for parameter");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) stmt->objtype);
@@ -640,6 +648,9 @@ ExecGrantStmt_oids(InternalGrant *istmt)
case OBJECT_PARAMETER_ACL:
ExecGrant_Parameter(istmt);
break;
+ case OBJECT_VARIABLE:
+ ExecGrant_common(istmt, VariableRelationId, ACL_ALL_RIGHTS_VARIABLE, NULL);
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) istmt->objtype);
@@ -760,6 +771,18 @@ objectNamesToOids(ObjectType objtype, List *objnames, bool is_grant)
objects = lappend_oid(objects, parameterId);
}
break;
+
+ case OBJECT_VARIABLE:
+ foreach_node(RangeVar, varvar, objnames)
+ {
+ Oid relOid;
+
+ relOid = LookupVariable(varvar->schemaname,
+ varvar->relname,
+ false);
+ objects = lappend_oid(objects, relOid);
+ }
+ break;
}
return objects;
@@ -846,6 +869,32 @@ objectsInSchemaToOids(ObjectType objtype, List *nspnames)
table_close(rel, AccessShareLock);
}
break;
+ case OBJECT_VARIABLE:
+ {
+ ScanKeyData key;
+ Relation rel;
+ TableScanDesc scan;
+ HeapTuple tuple;
+
+ ScanKeyInit(&key,
+ Anum_pg_variable_varnamespace,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(namespaceId));
+
+ rel = table_open(VariableRelationId, AccessShareLock);
+ scan = table_beginscan_catalog(rel, 1, &key);
+
+ while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+ {
+ Oid oid = ((Form_pg_proc) GETSTRUCT(tuple))->oid;
+
+ objects = lappend_oid(objects, oid);
+ }
+
+ table_endscan(scan);
+ table_close(rel, AccessShareLock);
+ }
+ break;
default:
/* should not happen */
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
@@ -1005,6 +1054,10 @@ ExecAlterDefaultPrivilegesStmt(ParseState *pstate, AlterDefaultPrivilegesStmt *s
all_privileges = ACL_ALL_RIGHTS_SCHEMA;
errormsg = gettext_noop("invalid privilege type %s for schema");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) action->objtype);
@@ -1196,6 +1249,12 @@ SetDefaultACL(InternalDefaultACL *iacls)
this_privileges = ACL_ALL_RIGHTS_SCHEMA;
break;
+ case OBJECT_VARIABLE:
+ objtype = DEFACLOBJ_VARIABLE;
+ if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
+ this_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ break;
+
default:
elog(ERROR, "unrecognized object type: %d",
(int) iacls->objtype);
@@ -1439,6 +1498,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case DEFACLOBJ_NAMESPACE:
iacls.objtype = OBJECT_SCHEMA;
break;
+ case DEFACLOBJ_VARIABLE:
+ iacls.objtype = OBJECT_VARIABLE;
+ break;
default:
/* Shouldn't get here */
elog(ERROR, "unexpected default ACL type: %d",
@@ -1499,6 +1561,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case ParameterAclRelationId:
istmt.objtype = OBJECT_PARAMETER_ACL;
break;
+ case VariableRelationId:
+ istmt.objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unexpected object class %u", classid);
break;
@@ -2732,6 +2797,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("permission denied for type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("permission denied for session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("permission denied for view %s");
break;
@@ -2843,6 +2911,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("must be owner of type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("must be owner of session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("must be owner of view %s");
break;
@@ -2991,6 +3062,8 @@ pg_aclmask(ObjectType objtype, Oid object_oid, AttrNumber attnum, Oid roleid,
return ACL_NO_RIGHTS;
case OBJECT_TYPE:
return object_aclmask(TypeRelationId, object_oid, roleid, mask, how);
+ case OBJECT_VARIABLE:
+ return object_aclmask(VariableRelationId, object_oid, roleid, mask, how);
default:
elog(ERROR, "unrecognized object type: %d",
(int) objtype);
@@ -4250,6 +4323,10 @@ get_user_default_acl(ObjectType objtype, Oid ownerId, Oid nsp_oid)
defaclobjtype = DEFACLOBJ_NAMESPACE;
break;
+ case OBJECT_VARIABLE:
+ defaclobjtype = DEFACLOBJ_VARIABLE;
+ break;
+
default:
return NULL;
}
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 18316a3968b..9e0f648b74f 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -65,12 +65,14 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/comment.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "commands/extension.h"
#include "commands/policy.h"
#include "commands/publicationcmds.h"
+#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
#include "commands/trigger.h"
@@ -1444,6 +1446,10 @@ doDeletion(const ObjectAddress *object, int flags)
RemovePublicationById(object->objectId);
break;
+ case VariableRelationId:
+ DropVariableById(object->objectId);
+ break;
+
case CastRelationId:
case CollationRelationId:
case ConversionRelationId:
diff --git a/src/backend/catalog/meson.build b/src/backend/catalog/meson.build
index 1958ea9238a..ed44c877fca 100644
--- a/src/backend/catalog/meson.build
+++ b/src/backend/catalog/meson.build
@@ -32,6 +32,7 @@ backend_sources += files(
'pg_shdepend.c',
'pg_subscription.c',
'pg_type.c',
+ 'pg_variable.c',
'storage.c',
'toasting.c',
)
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index d97d632a7ef..4307cad15c7 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "common/hashfn_unstable.h"
#include "funcapi.h"
@@ -225,6 +226,7 @@ static bool TSParserIsVisibleExt(Oid prsId, bool *is_missing);
static bool TSDictionaryIsVisibleExt(Oid dictId, bool *is_missing);
static bool TSTemplateIsVisibleExt(Oid tmplId, bool *is_missing);
static bool TSConfigIsVisibleExt(Oid cfgid, bool *is_missing);
+static bool VariableIsVisibleExt(Oid varid, bool *is_missing);
static void recomputeNamespacePath(void);
static void AccessTempTableNamespace(bool force);
static void InitTempTableNamespace(void);
@@ -986,6 +988,84 @@ RelationIsVisibleExt(Oid relid, bool *is_missing)
return visible;
}
+/*
+ * VariableIsVisible
+ * Determine whether a variable (identified by OID) is visible in the
+ * current search path. Visible means "would be found by searching
+ * for the unqualified variable name".
+ */
+bool
+VariableIsVisible(Oid varid)
+{
+ return VariableIsVisibleExt(varid, NULL);
+}
+
+/*
+ * VariableIsVisibleExt
+ * As above, but if the variable isn't found and is_missing is not NULL,
+ * then set *is_missing = true and return false, instead of throwing
+ * an error. (Caller must initialize *is_missing = false.)
+ */
+static bool
+VariableIsVisibleExt(Oid varid, bool *is_missing)
+{
+ HeapTuple vartup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+ bool visible;
+
+ vartup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+ if (!HeapTupleIsValid(vartup))
+ {
+ if (is_missing != NULL)
+ {
+ *is_missing = true;
+ return false;
+ }
+
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+ }
+ varform = (Form_pg_variable) GETSTRUCT(vartup);
+
+ recomputeNamespacePath();
+
+ /*
+ * Quick check: if it ain't in the path at all, it ain't visible. We
+ * don't expect usage of session variables in the system namespace.
+ */
+ varnamespace = varform->varnamespace;
+ if (!list_member_oid(activeSearchPath, varnamespace))
+ visible = false;
+ else
+ {
+ /*
+ * If it is in the path, it might still not be visible; it could be
+ * hidden by another variable of the same name earlier in the path. So
+ * we must do a slow check for conflicting relations.
+ */
+ char *varname = NameStr(varform->varname);
+
+ visible = false;
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ if (namespaceId == varnamespace)
+ {
+ /* found it first in path */
+ visible = true;
+ break;
+ }
+ if (OidIsValid(get_varname_varid(varname, namespaceId)))
+ {
+ /* found something else first in path */
+ break;
+ }
+ }
+ }
+
+ ReleaseSysCache(vartup);
+
+ return visible;
+}
/*
* TypenameGetTypid
@@ -3289,6 +3369,133 @@ TSConfigIsVisibleExt(Oid cfgid, bool *is_missing)
return visible;
}
+/*
+ * Returns oid of session variable specified by possibly qualified identifier.
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariable(const char *nspname,
+ const char *varname,
+ bool missing_ok)
+{
+ Oid varoid = InvalidOid;
+
+ if (nspname)
+ {
+ Oid namespaceId = LookupExplicitNamespace(nspname, missing_ok);
+
+ /* if nspname is a known namespace, the variable must be there */
+ if (OidIsValid(namespaceId))
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+ }
+ }
+ else
+ {
+ /* iterate over the schemas on the search_path */
+ recomputeNamespacePath();
+
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+
+ if (OidIsValid(varoid))
+ break;
+ }
+ }
+
+ if (!OidIsValid(varoid) && !missing_ok)
+ {
+ if (nspname)
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s.%s\" does not exist",
+ nspname, varname)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" does not exist",
+ varname)));
+ }
+
+ return varoid;
+}
+
+/*
+ * Returns oid of session variable specified by possibly qualified identifier
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariableFromNameList(List *names,
+ bool missing_ok)
+{
+ char *catname = NULL;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ switch (list_length(names))
+ {
+ case 1:
+ varname = strVal(linitial(names));
+ break;
+ case 2:
+ nspname = strVal(linitial(names));
+ varname = strVal(lsecond(names));
+ break;
+ case 3:
+ catname = strVal(linitial(names));
+ nspname = strVal(lsecond(names));
+ varname = strVal(lthird(names));
+
+ /* check catalog name */
+ if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ break;
+ default:
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper session variable name (too many dotted names): %s",
+ NameListToString(names))));
+ break;
+ }
+
+ return LookupVariable(nspname, varname, missing_ok);
+}
+
+/*
+ * The input list contains names with indirection expressions used as the left
+ * part of LET statement. The following routine returns a new list with only
+ * initial strings (names) - without indirection expressions.
+ */
+List *
+NamesFromList(List *names)
+{
+ ListCell *l;
+ List *result = NIL;
+
+ foreach(l, names)
+ {
+ Node *n = lfirst(l);
+
+ if (IsA(n, String))
+ {
+ result = lappend(result, n);
+ }
+ else
+ break;
+ }
+
+ return result;
+}
/*
* DeconstructQualifiedName
@@ -5085,3 +5292,17 @@ pg_is_other_temp_schema(PG_FUNCTION_ARGS)
PG_RETURN_BOOL(isOtherTempNamespace(oid));
}
+
+Datum
+pg_variable_is_visible(PG_FUNCTION_ARGS)
+{
+ Oid oid = PG_GETARG_OID(0);
+ bool result;
+ bool is_missing = false;
+
+ result = VariableIsVisibleExt(oid, &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+ PG_RETURN_BOOL(result);
+}
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index d8eb8d3deaa..4a464dfea7e 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -62,6 +62,7 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -636,6 +637,20 @@ static const ObjectPropertyType ObjectProperty[] =
OBJECT_USER_MAPPING,
false
},
+ {
+ "session variable",
+ VariableRelationId,
+ VariableOidIndexId,
+ VARIABLEOID,
+ VARIABLENAMENSP,
+ Anum_pg_variable_oid,
+ Anum_pg_variable_varname,
+ Anum_pg_variable_varnamespace,
+ Anum_pg_variable_varowner,
+ Anum_pg_variable_varacl,
+ OBJECT_VARIABLE,
+ true
+ }
};
/*
@@ -831,6 +846,9 @@ static const struct object_type_map
},
{
"statistics object", OBJECT_STATISTIC_EXT
+ },
+ {
+ "session variable", OBJECT_VARIABLE
}
};
@@ -856,6 +874,7 @@ static ObjectAddress get_object_address_attrdef(ObjectType objtype,
bool missing_ok);
static ObjectAddress get_object_address_type(ObjectType objtype,
TypeName *typename, bool missing_ok);
+static ObjectAddress get_object_address_variable(List *object, bool missing_ok);
static ObjectAddress get_object_address_opcf(ObjectType objtype, List *object,
bool missing_ok);
static ObjectAddress get_object_address_opf_member(ObjectType objtype,
@@ -1127,6 +1146,9 @@ get_object_address(ObjectType objtype, Node *object,
missing_ok);
address.objectSubId = 0;
break;
+ case OBJECT_VARIABLE:
+ address = get_object_address_variable(castNode(List, object), missing_ok);
+ break;
/* no default, to let compiler warn about missing case */
}
@@ -2005,16 +2027,20 @@ get_object_address_defacl(List *object, bool missing_ok)
case DEFACLOBJ_NAMESPACE:
objtype_str = "schemas";
break;
+ case DEFACLOBJ_VARIABLE:
+ objtype_str = "variables";
+ break;
default:
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized default ACL object type \"%c\"", objtype),
- errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
+ errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
DEFACLOBJ_RELATION,
DEFACLOBJ_SEQUENCE,
DEFACLOBJ_FUNCTION,
DEFACLOBJ_TYPE,
- DEFACLOBJ_NAMESPACE)));
+ DEFACLOBJ_NAMESPACE,
+ DEFACLOBJ_VARIABLE)));
}
/*
@@ -2098,6 +2124,24 @@ textarray_to_strvaluelist(ArrayType *arr)
return list;
}
+/*
+ * Find the ObjectAddress for a session variable
+ */
+static ObjectAddress
+get_object_address_variable(List *object, bool missing_ok)
+{
+ ObjectAddress address;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ ObjectAddressSet(address, VariableRelationId, InvalidOid);
+
+ DeconstructQualifiedName(object, &nspname, &varname);
+ address.objectId = LookupVariable(nspname, varname, missing_ok);
+
+ return address;
+}
+
/*
* SQL-callable version of get_object_address
*/
@@ -2292,6 +2336,7 @@ pg_get_object_address(PG_FUNCTION_ARGS)
case OBJECT_TABCONSTRAINT:
case OBJECT_OPCLASS:
case OBJECT_OPFAMILY:
+ case OBJECT_VARIABLE:
objnode = (Node *) name;
break;
case OBJECT_ACCESS_METHOD:
@@ -2463,6 +2508,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
case OBJECT_STATISTIC_EXT:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
if (!object_ownercheck(address.classId, address.objectId, roleid))
aclcheck_error(ACLCHECK_NOT_OWNER, objtype,
NameListToString(castNode(List, object)));
@@ -3492,6 +3538,32 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
break;
}
+ case VariableRelationId:
+ {
+ char *nspname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ if (VariableIsVisible(object->objectId))
+ nspname = NULL;
+ else
+ nspname = get_namespace_name(varform->varnamespace);
+
+ appendStringInfo(&buffer, _("session variable %s"),
+ quote_qualified_identifier(nspname,
+ NameStr(varform->varname)));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
case TSParserRelationId:
{
HeapTuple tup;
@@ -3844,6 +3916,16 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
_("default privileges on new schemas belonging to role %s"),
rolename);
break;
+ case DEFACLOBJ_VARIABLE:
+ if (nspname)
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s in schema %s"),
+ rolename, nspname);
+ else
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s"),
+ rolename);
+ break;
default:
/* shouldn't get here */
if (nspname)
@@ -4660,6 +4742,10 @@ getObjectTypeDescription(const ObjectAddress *object, bool missing_ok)
appendStringInfoString(&buffer, "transform");
break;
+ case VariableRelationId:
+ appendStringInfoString(&buffer, "session variable");
+ break;
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
@@ -5766,6 +5852,10 @@ getObjectIdentityParts(const ObjectAddress *object,
appendStringInfoString(&buffer,
" on schemas");
break;
+ case DEFACLOBJ_VARIABLE:
+ appendStringInfoString(&buffer,
+ " on session variables");
+ break;
}
if (objname)
@@ -6006,6 +6096,33 @@ getObjectIdentityParts(const ObjectAddress *object,
}
break;
+ case VariableRelationId:
+ {
+ char *schema;
+ char *varname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ schema = get_namespace_name_or_temp(varform->varnamespace);
+ varname = NameStr(varform->varname);
+
+ appendStringInfo(&buffer, "%s",
+ quote_qualified_identifier(schema, varname));
+
+ if (objname)
+ *objname = list_make2(schema, pstrdup(varname));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
diff --git a/src/backend/catalog/pg_shdepend.c b/src/backend/catalog/pg_shdepend.c
index 536191284e8..c6fd1fa074f 100644
--- a/src/backend/catalog/pg_shdepend.c
+++ b/src/backend/catalog/pg_shdepend.c
@@ -46,6 +46,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
@@ -1714,6 +1715,7 @@ shdepReassignOwned_Owner(Form_pg_shdepend sdepForm, Oid newrole)
case DatabaseRelationId:
case TSConfigRelationId:
case TSDictionaryRelationId:
+ case VariableRelationId:
AlterObjectOwner_internal(sdepForm->classid,
sdepForm->objid,
newrole);
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
new file mode 100644
index 00000000000..29d967a2d5b
--- /dev/null
+++ b/src/backend/catalog/pg_variable.c
@@ -0,0 +1,251 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.c
+ * session variables
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/catalog/pg_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "catalog/dependency.h"
+#include "catalog/indexing.h"
+#include "catalog/namespace.h"
+#include "catalog/objectaccess.h"
+#include "catalog/pg_collation.h"
+#include "catalog/pg_namespace.h"
+#include "catalog/pg_variable.h"
+#include "miscadmin.h"
+#include "parser/parse_type.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+static ObjectAddress create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists);
+
+
+/*
+ * Creates entry in pg_variable table
+ */
+static ObjectAddress
+create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists)
+{
+ Acl *varacl;
+ NameData varname;
+ bool nulls[Natts_pg_variable];
+ Datum values[Natts_pg_variable];
+ Relation rel;
+ HeapTuple tup;
+ TupleDesc tupdesc;
+ ObjectAddress myself,
+ referenced;
+ ObjectAddresses *addrs;
+ Oid varid;
+
+ Assert(varName);
+ Assert(OidIsValid(varNamespace));
+ Assert(OidIsValid(varType));
+ Assert(OidIsValid(varOwner));
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ /*
+ * Check for duplicates. Note that this does not really prevent
+ * duplicates, it's here just to provide nicer error message in common
+ * case. The real protection is the unique key on the catalog.
+ */
+ if (SearchSysCacheExists2(VARIABLENAMENSP,
+ PointerGetDatum(varName),
+ ObjectIdGetDatum(varNamespace)))
+ {
+ if (if_not_exists)
+ ereport(NOTICE,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists, skipping",
+ varName)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists",
+ varName)));
+
+ table_close(rel, RowExclusiveLock);
+
+ return InvalidObjectAddress;
+ }
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, false, sizeof(nulls));
+
+ namestrcpy(&varname, varName);
+
+ varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
+
+ values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
+ values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
+ values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
+ values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
+ values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
+ values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+
+ varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
+ varNamespace);
+ if (varacl != NULL)
+ values[Anum_pg_variable_varacl - 1] = PointerGetDatum(varacl);
+ else
+ nulls[Anum_pg_variable_varacl - 1] = true;
+
+ tupdesc = RelationGetDescr(rel);
+
+ tup = heap_form_tuple(tupdesc, values, nulls);
+ CatalogTupleInsert(rel, tup);
+ Assert(OidIsValid(varid));
+
+ addrs = new_object_addresses();
+
+ ObjectAddressSet(myself, VariableRelationId, varid);
+
+ /* dependency on namespace */
+ ObjectAddressSet(referenced, NamespaceRelationId, varNamespace);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on used type */
+ ObjectAddressSet(referenced, TypeRelationId, varType);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on collation */
+ if (OidIsValid(varCollation) &&
+ varCollation != DEFAULT_COLLATION_OID)
+ {
+ ObjectAddressSet(referenced, CollationRelationId, varCollation);
+ add_exact_object_address(&referenced, addrs);
+ }
+
+ record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
+ free_object_addresses(addrs);
+
+ /* dependency on owner */
+ recordDependencyOnOwner(VariableRelationId, varid, varOwner);
+
+ /* dependencies on roles mentioned in default ACL */
+ recordDependencyOnNewAcl(VariableRelationId, varid, 0, varOwner, varacl);
+
+ /* dependency on extension */
+ recordDependencyOnCurrentExtension(&myself, false);
+
+ heap_freetuple(tup);
+
+ /* post creation hook for new function */
+ InvokeObjectPostCreateHook(VariableRelationId, varid, 0);
+
+ table_close(rel, RowExclusiveLock);
+
+ return myself;
+}
+
+/*
+ * Creates a new variable
+ *
+ * Used by CREATE VARIABLE command
+ */
+ObjectAddress
+CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
+{
+ Oid namespaceid;
+ AclResult aclresult;
+ Oid typid;
+ int32 typmod;
+ Oid varowner = GetUserId();
+ Oid collation;
+ Oid typcollation;
+ ObjectAddress variable;
+
+ namespaceid =
+ RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL);
+
+ typenameTypeIdAndMod(pstate, stmt->typeName, &typid, &typmod);
+
+ /* disallow pseudotypes */
+ if (get_typtype(typid) == TYPTYPE_PSEUDO)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("session variable cannot be pseudo-type %s",
+ format_type_be(typid))));
+
+ aclresult = object_aclcheck(TypeRelationId, typid, GetUserId(), ACL_USAGE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error_type(aclresult, typid);
+
+ typcollation = get_typcollation(typid);
+
+ if (stmt->collClause)
+ collation = LookupCollation(pstate,
+ stmt->collClause->collname,
+ stmt->collClause->location);
+ else
+ collation = typcollation;
+
+ /* complain if COLLATE is applied to an uncollatable type */
+ if (OidIsValid(collation) && !OidIsValid(typcollation))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("collations are not supported by type %s",
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->collClause->location)));
+
+ variable = create_variable(stmt->variable->relname,
+ namespaceid,
+ typid,
+ typmod,
+ varowner,
+ collation,
+ stmt->if_not_exists);
+
+ elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
+ stmt->variable->relname, variable.objectId);
+
+ return variable;
+}
+
+/*
+ * Drop variable by OID
+ */
+void
+DropVariableById(Oid varid)
+{
+ Relation rel;
+ HeapTuple tup;
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ CatalogTupleDelete(rel, &tup->t_self);
+
+ ReleaseSysCache(tup);
+
+ table_close(rel, RowExclusiveLock);
+}
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 78c1d4e1b84..67153cd8b94 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/collationcmds.h"
#include "commands/dbcommands.h"
@@ -140,6 +141,10 @@ report_namespace_conflict(Oid classId, const char *name, Oid nspOid)
Assert(OidIsValid(nspOid));
msgfmt = gettext_noop("text search configuration \"%s\" already exists in schema \"%s\"");
break;
+ case VariableRelationId:
+ Assert(OidIsValid(nspOid));
+ msgfmt = gettext_noop("session variable \"%s\" already exists in schema \"%s\"");
+ break;
default:
elog(ERROR, "unsupported object class: %u", classId);
break;
@@ -419,6 +424,7 @@ ExecRenameStmt(RenameStmt *stmt)
case OBJECT_TSTEMPLATE:
case OBJECT_PUBLICATION:
case OBJECT_SUBSCRIPTION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
Relation catalog;
@@ -559,6 +565,7 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt,
case OBJECT_TSDICTIONARY:
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
+ case OBJECT_VARIABLE:
{
Relation catalog;
Oid classId;
@@ -641,6 +648,7 @@ AlterObjectNamespace_oid(Oid classId, Oid objid, Oid nspOid,
case TSDictionaryRelationId:
case TSTemplateRelationId:
case TSConfigRelationId:
+ case VariableRelationId:
{
Relation catalog;
@@ -871,6 +879,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
case OBJECT_TABLESPACE:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
diff --git a/src/backend/commands/dropcmds.c b/src/backend/commands/dropcmds.c
index ceb9a229b63..ebb585dc4a1 100644
--- a/src/backend/commands/dropcmds.c
+++ b/src/backend/commands/dropcmds.c
@@ -476,6 +476,10 @@ does_not_exist_skipping(ObjectType objtype, Node *object)
msg = gettext_noop("publication \"%s\" does not exist, skipping");
name = strVal(object);
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("session variable \"%s\" does not exist, skipping");
+ name = NameListToString(castNode(List, object));
+ break;
case OBJECT_COLUMN:
case OBJECT_DATABASE:
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index edc2c988e29..1839c1f82c5 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -2149,6 +2149,8 @@ stringify_grant_objtype(ObjectType objtype)
return "TABLESPACE";
case OBJECT_TYPE:
return "TYPE";
+ case OBJECT_VARIABLE:
+ return "VARIABLE";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
@@ -2232,6 +2234,8 @@ stringify_adefprivs_objtype(ObjectType objtype)
return "TABLESPACES";
case OBJECT_TYPE:
return "TYPES";
+ case OBJECT_VARIABLE:
+ return "VARIABLES";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
diff --git a/src/backend/commands/seclabel.c b/src/backend/commands/seclabel.c
index cee5d7bbb9c..57b4e6719c2 100644
--- a/src/backend/commands/seclabel.c
+++ b/src/backend/commands/seclabel.c
@@ -92,6 +92,7 @@ SecLabelSupportsObjectType(ObjectType objtype)
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
case OBJECT_USER_MAPPING:
+ case OBJECT_VARIABLE:
return false;
/*
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index ce7d115667e..b69153ebfa7 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -52,6 +52,7 @@
#include "catalog/pg_tablespace.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "catalog/storage.h"
#include "catalog/storage_xlog.h"
#include "catalog/toasting.h"
@@ -6824,6 +6825,7 @@ ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
* (possibly nested several levels deep in composite types, arrays, etc!).
* Eventually, we'd like to propagate the check or rewrite operation
* into such tables, but for now, just error out if we find any.
+ * Also, check if "typeOid" is used as type of some session variable.
*
* Caller should provide either the associated relation of a rowtype,
* or a type name (not both) for use in the error message, if any.
@@ -6887,6 +6889,45 @@ find_composite_type_dependencies(Oid typeOid, Relation origRelation,
continue;
}
+ /* check if the type is used as type of some session variable */
+ if (pg_depend->classid == VariableRelationId)
+ {
+ Oid varid = pg_depend->objid;
+
+ if (origTypeName)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ origTypeName,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter foreign table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_RELATION ||
+ origRelation->rd_rel->relkind == RELKIND_MATVIEW ||
+ origRelation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+
+ continue;
+ }
+
/* Else, ignore dependees that aren't relations */
if (pg_depend->classid != RelationRelationId)
continue;
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 3cb3ca1cca1..473d98ff062 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -53,6 +53,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_range.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablecmds.h"
#include "commands/typecmds.h"
@@ -3369,6 +3370,20 @@ get_rels_with_domain(Oid domainOid, LOCKMODE lockmode)
}
continue;
}
+ else if (pg_depend->classid == VariableRelationId)
+ {
+ /*
+ * We cannot to validate constraint inside session variables
+ * from other sessions, so better to fail if there are any
+ * session variable, that use this domain.
+ */
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter domain \"%s\" because session variable \"%s.%s\" uses it",
+ domainTypeName,
+ get_namespace_name(get_session_variable_namespace(pg_depend->objid)),
+ get_session_variable_name(pg_depend->objid))));
+ }
/* Else, ignore dependees that aren't user columns of relations */
/* (we assume system columns are never of domain types) */
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 7d99c9355c6..6c95950b99b 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -52,6 +52,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_am.h"
#include "catalog/pg_trigger.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/trigger.h"
#include "gramparse.h"
@@ -285,8 +286,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
ConstraintsSetStmt CopyStmt CreateAsStmt CreateCastStmt
CreateDomainStmt CreateExtensionStmt CreateGroupStmt CreateOpClassStmt
CreateOpFamilyStmt AlterOpFamilyStmt CreatePLangStmt
- CreateSchemaStmt CreateSeqStmt CreateStmt CreateStatsStmt CreateTableSpaceStmt
- CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
+ CreateSchemaStmt CreateSeqStmt CreateSessionVarStmt CreateStmt CreateStatsStmt
+ CreateTableSpaceStmt CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
CreateAssertionStmt CreateTransformStmt CreateTrigStmt CreateEventTrigStmt
CreateUserStmt CreateUserMappingStmt CreateRoleStmt CreatePolicyStmt
CreatedbStmt DeclareCursorStmt DefineStmt DeleteStmt DiscardStmt DoStmt
@@ -783,8 +784,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
UESCAPE UNBOUNDED UNCONDITIONAL UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN
UNLISTEN UNLOGGED UNTIL UPDATE USER USING
- VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
- VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
+ VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARIABLE
+ VARIABLES VARYING VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
@@ -1050,6 +1051,7 @@ stmt:
| CreatePolicyStmt
| CreatePLangStmt
| CreateSchemaStmt
+ | CreateSessionVarStmt
| CreateSeqStmt
| CreateStmt
| CreateSubscriptionStmt
@@ -1592,6 +1594,7 @@ schema_stmt:
| CreateTrigStmt
| GrantStmt
| ViewStmt
+ | CreateSessionVarStmt
;
@@ -5245,6 +5248,34 @@ create_extension_opt_item:
}
;
+/*****************************************************************************
+ *
+ * QUERY :
+ * CREATE VARIABLE varname [AS] type
+ *
+ *****************************************************************************/
+
+CreateSessionVarStmt:
+ CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $3;
+ n->typeName = $5;
+ n->collClause = (CollateClause *) $6;
+ n->if_not_exists = false;
+ $$ = (Node *) n;
+ }
+ | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $6;
+ n->typeName = $8;
+ n->collClause = (CollateClause *) $9;
+ n->if_not_exists = true;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
@@ -7036,6 +7067,7 @@ object_type_any_name:
| TEXT_P SEARCH DICTIONARY { $$ = OBJECT_TSDICTIONARY; }
| TEXT_P SEARCH TEMPLATE { $$ = OBJECT_TSTEMPLATE; }
| TEXT_P SEARCH CONFIGURATION { $$ = OBJECT_TSCONFIGURATION; }
+ | VARIABLE { $$ = OBJECT_VARIABLE; }
;
/*
@@ -7912,6 +7944,14 @@ privilege_target:
n->objs = $2;
$$ = n;
}
+ | VARIABLE qualified_name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_OBJECT;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $2;
+ $$ = n;
+ }
| ALL TABLES IN_P SCHEMA name_list
{
PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
@@ -7957,6 +7997,14 @@ privilege_target:
n->objs = $5;
$$ = n;
}
+ | ALL VARIABLES IN_P SCHEMA name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_ALL_IN_SCHEMA;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $5;
+ $$ = n;
+ }
;
@@ -8154,6 +8202,7 @@ defacl_privilege_target:
| SEQUENCES { $$ = OBJECT_SEQUENCE; }
| TYPES_P { $$ = OBJECT_TYPE; }
| SCHEMAS { $$ = OBJECT_SCHEMA; }
+ | VARIABLES { $$ = OBJECT_VARIABLE; }
;
@@ -9942,6 +9991,24 @@ RenameStmt: ALTER AGGREGATE aggregate_with_argtypes RENAME TO name
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newname = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newname = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
opt_column: COLUMN
@@ -10303,6 +10370,24 @@ AlterObjectSchemaStmt:
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newschema = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newschema = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
/*****************************************************************************
@@ -10584,6 +10669,14 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec
n->newowner = $6;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name OWNER TO RoleSpec
+ {
+ AlterOwnerStmt *n = makeNode(AlterOwnerStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newowner = $6;
+ $$ = (Node *)n;
+ }
;
@@ -17993,6 +18086,8 @@ unreserved_keyword:
| VALIDATE
| VALIDATOR
| VALUE_P
+ | VARIABLE
+ | VARIABLES
| VARYING
| VERSION_P
| VIEW
@@ -18648,6 +18743,8 @@ bare_label_keyword:
| VALUE_P
| VALUES
| VARCHAR
+ | VARIABLE
+ | VARIABLES
| VARIADIC
| VERBOSE
| VERSION_P
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index abbe1bb45a3..14ed3cd9b3e 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -105,6 +105,7 @@ typedef struct
List *indexes; /* CREATE INDEX items */
List *triggers; /* CREATE TRIGGER items */
List *grants; /* GRANT items */
+ List *variables; /* CREATE VARIABLE items */
} CreateSchemaStmtContext;
@@ -4102,6 +4103,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.indexes = NIL;
cxt.triggers = NIL;
cxt.grants = NIL;
+ cxt.variables = NIL;
/*
* Run through each schema element in the schema element list. Separate
@@ -4170,6 +4172,15 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.grants = lappend(cxt.grants, element);
break;
+ case T_CreateSessionVarStmt:
+ {
+ CreateSessionVarStmt *elp = (CreateSessionVarStmt *) element;
+
+ setSchemaName(cxt.schemaname, &elp->variable->schemaname);
+ cxt.variables = lappend(cxt.variables, element);
+ }
+ break;
+
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(element));
@@ -4183,6 +4194,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
result = list_concat(result, cxt.indexes);
result = list_concat(result, cxt.triggers);
result = list_concat(result, cxt.grants);
+ result = list_concat(result, cxt.variables);
return result;
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 25fe3d58016..99a51877d34 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -23,6 +23,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_inherits.h"
+#include "catalog/pg_variable.h"
#include "catalog/toasting.h"
#include "commands/alter.h"
#include "commands/async.h"
@@ -182,6 +183,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CreateRangeStmt:
case T_CreateRoleStmt:
case T_CreateSchemaStmt:
+ case T_CreateSessionVarStmt:
case T_CreateSeqStmt:
case T_CreateStatsStmt:
case T_CreateStmt:
@@ -1389,6 +1391,10 @@ ProcessUtilitySlow(ParseState *pstate,
}
break;
+ case T_CreateSessionVarStmt:
+ address = CreateVariable(pstate, (CreateSessionVarStmt *) parsetree);
+ break;
+
/*
* ************* object creation / destruction **************
*/
@@ -2341,6 +2347,9 @@ AlterObjectTypeCommandTag(ObjectType objtype)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_ALTER_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_ALTER_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
break;
@@ -2649,6 +2658,9 @@ CreateCommandTag(Node *parsetree)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_DROP_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_DROP_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
@@ -3225,6 +3237,10 @@ CreateCommandTag(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ tag = CMDTAG_CREATE_VARIABLE;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
@@ -3759,6 +3775,10 @@ GetCommandLogLevel(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ lev = LOGSTMT_DDL;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index 6a76550a5e2..377de0b7c6b 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -31,6 +31,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/proclang.h"
#include "commands/tablespace.h"
@@ -129,6 +130,8 @@ static AclMode convert_type_priv_string(text *priv_type_text);
static AclMode convert_parameter_priv_string(text *priv_text);
static AclMode convert_largeobject_priv_string(text *priv_text);
static AclMode convert_role_priv_string(text *priv_type_text);
+static Oid convert_session_variable_name(text *varname);
+static AclMode convert_session_variable_priv_string(text *priv_type_text);
static AclResult pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode);
static void RoleMembershipCacheCallback(Datum arg, int cacheid, uint32 hashvalue);
@@ -851,6 +854,10 @@ acldefault(ObjectType objtype, Oid ownerId)
world_default = ACL_NO_RIGHTS;
owner_default = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ world_default = ACL_NO_RIGHTS;
+ owner_default = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", (int) objtype);
world_default = ACL_NO_RIGHTS; /* keep compiler quiet */
@@ -948,6 +955,9 @@ acldefault_sql(PG_FUNCTION_ARGS)
case 'T':
objtype = OBJECT_TYPE;
break;
+ case 'V':
+ objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type abbreviation: %c", objtypec);
}
@@ -5016,6 +5026,217 @@ pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode)
return ACLCHECK_NO_PRIV;
}
+/*
+ * has_session_variable_privilege variants
+ * These are all named "has_session_variable_privilege" at the SQL level.
+ * They take various combinations of variable name, variable OID,
+ * user name, user OID, or implicit user = current_user.
+ *
+ * The result is a boolean value: true if user has the indicated
+ * privilege, false if not, or NULL if session variable doesn't
+ * exists.
+ */
+
+/*
+ * has_session_variable_privilege_name_name
+ * Check user privileges on a session variable given
+ * name username, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_name(PG_FUNCTION_ARGS)
+{
+ Name rolename = PG_GETARG_NAME(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*rolename));
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name
+ * Check user privileges on a session variable given
+ * text session variable and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_name(PG_FUNCTION_ARGS)
+{
+ text *varname = PG_GETARG_TEXT_PP(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name_id
+ * Check user privileges on a session variable given
+ * name usename, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_id(PG_FUNCTION_ARGS)
+{
+ Name username = PG_GETARG_NAME(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*username));
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id
+ * Check user privileges on a session variable given
+ * session variable oid, and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_id(PG_FUNCTION_ARGS)
+{
+ Oid varid = PG_GETARG_OID(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_name
+ * Check user privileges on a session variable given
+ * roleid, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_name(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_id
+ * Check user privileges on a session variable given
+ * roleid, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_id(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * Given a session variable name expressed as a string, look it up and return
+ * Oid
+ */
+static Oid
+convert_session_variable_name(text *varname)
+{
+ return LookupVariableFromNameList(textToQualifiedNameList(varname), true);
+}
+
+/*
+ * convert_variable_priv_string
+ * Convert text string to AclMode value.
+ */
+static AclMode
+convert_session_variable_priv_string(text *priv_type_text)
+{
+ static const priv_map session_variable_priv_map[] = {
+ {"SELECT", ACL_SELECT},
+ {"SELECT WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_SELECT)},
+ {"UPDATE", ACL_UPDATE},
+ {"UPDATE WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_UPDATE)},
+ {NULL, 0}
+ };
+
+ return convert_any_priv_string(priv_type_text, session_variable_priv_map);
+}
/*
* initialization function (called by InitPostgres)
diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index 7bd476f3de7..46cbbbeee9d 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -39,6 +39,7 @@
#include "catalog/pg_subscription.h"
#include "catalog/pg_transform.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "utils/array.h"
@@ -3741,3 +3742,115 @@ get_subscription_name(Oid subid, bool missing_ok)
return subname;
}
+
+/* ---------- PG_VARIABLE CACHE ---------- */
+
+/*
+ * get_varname_varid
+ * Given name and namespace of variable, look up the OID.
+ */
+Oid
+get_varname_varid(const char *varname, Oid varnamespace)
+{
+ return GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(varnamespace));
+}
+
+/*
+ * get_session_variable_name
+ * Returns a palloc'd copy of the name of a given session variable.
+ */
+char *
+get_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = pstrdup(NameStr(varform->varname));
+
+ ReleaseSysCache(tup);
+
+ return varname;
+}
+
+/*
+ * get_session_variable_namespace
+ * Returns the pg_namespace OID associated with a given session variable.
+ */
+Oid
+get_session_variable_namespace(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varnamespace = varform->varnamespace;
+
+ ReleaseSysCache(tup);
+
+ return varnamespace;
+}
+
+/*
+ * Returns the type of the given session variable.
+ */
+Oid
+get_session_variable_type(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid vartype;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ vartype = varform->vartype;
+
+ ReleaseSysCache(tup);
+
+ return vartype;
+}
+
+/*
+ * Returns the type, typmod and collid of the given session variable.
+ */
+void
+get_session_variable_type_typmod_collid(Oid varid, Oid *typid, int32 *typmod,
+ Oid *collid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ *typid = varform->vartype;
+ *typmod = varform->vartypmod;
+ *collid = varform->varcollation;
+
+ ReleaseSysCache(tup);
+}
diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c
index 56b6c368acf..ba6b19dc9af 100644
--- a/src/bin/pg_dump/common.c
+++ b/src/bin/pg_dump/common.c
@@ -246,6 +246,9 @@ getSchemaData(Archive *fout, int *numTablesPtr)
pg_log_info("reading subscription membership of tables");
getSubscriptionTables(fout);
+ pg_log_info("reading variables");
+ getVariables(fout);
+
free(inhinfo); /* not needed any longer */
*numTablesPtr = numTables;
diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index 5ae77f76367..5161ee780ea 100644
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -511,6 +511,12 @@ do { \
CONVERT_PRIV('r', "SELECT");
CONVERT_PRIV('w', "UPDATE");
}
+ else if (strcmp(type, "VARIABLE") == 0 ||
+ strcmp(type, "VARIABLES") == 0)
+ {
+ CONVERT_PRIV('r', "SELECT");
+ CONVERT_PRIV('w', "UPDATE");
+ }
else
abort();
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index e783cc68d89..fe8ec67f0bd 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -133,12 +133,14 @@ typedef struct _restoreOptions
int selFunction;
int selTrigger;
int selTable;
+ int selVariable;
SimpleStringList indexNames;
SimpleStringList functionNames;
SimpleStringList schemaNames;
SimpleStringList schemaExcludeNames;
SimpleStringList triggerNames;
SimpleStringList tableNames;
+ SimpleStringList variableNames;
int useDB;
ConnParams cparams; /* parameters to use if useDB */
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 632077113a4..1f6b56fd765 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -3129,6 +3129,14 @@ _tocEntryRequired(TocEntry *te, teSection curSection, ArchiveHandle *AH)
!simple_string_list_member(&ropt->triggerNames, te->tag))
return 0;
}
+ else if (strcmp(te->desc, "VARIABLE") == 0)
+ {
+ if (!ropt->selVariable)
+ return 0;
+ if (ropt->variableNames.head != NULL &&
+ !simple_string_list_member(&ropt->variableNames, te->tag))
+ return 0;
+ }
else
return 0;
}
@@ -3679,6 +3687,7 @@ _getObjectDescription(PQExpBuffer buf, const TocEntry *te)
strcmp(type, "TEXT SEARCH DICTIONARY") == 0 ||
strcmp(type, "TEXT SEARCH CONFIGURATION") == 0 ||
strcmp(type, "TYPE") == 0 ||
+ strcmp(type, "VARIABLE") == 0 ||
strcmp(type, "VIEW") == 0 ||
/* non-schema-specified objects */
strcmp(type, "DATABASE") == 0 ||
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 4f4ad2ee150..1c2d71654ea 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -365,6 +365,7 @@ static void dumpPublication(Archive *fout, const PublicationInfo *pubinfo);
static void dumpPublicationTable(Archive *fout, const PublicationRelInfo *pubrinfo);
static void dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo);
static void dumpSubscriptionTable(Archive *fout, const SubRelInfo *subrinfo);
+static void dumpVariable(Archive *fout, const VariableInfo *varinfo);
static void dumpDatabase(Archive *fout);
static void dumpDatabaseConfig(Archive *AH, PQExpBuffer outbuf,
const char *dbname, Oid dboid);
@@ -5454,6 +5455,188 @@ get_next_possible_free_pg_type_oid(Archive *fout, PQExpBuffer upgrade_query)
return next_possible_free_oid;
}
+/*
+ * getVariables
+ * get information about variables
+ */
+void
+getVariables(Archive *fout)
+{
+ PQExpBuffer query;
+ PGresult *res;
+ VariableInfo *varinfo;
+ int i_tableoid;
+ int i_oid;
+ int i_varname;
+ int i_varnamespace;
+ int i_vartype;
+ int i_vartypname;
+ int i_varowner;
+ int i_varcollation;
+ int i_varacl;
+ int i_acldefault;
+ int i,
+ ntups;
+
+ if (fout->remoteVersion < 180000)
+ return;
+
+ query = createPQExpBuffer();
+
+ /* get the variables in current database */
+ appendPQExpBuffer(query,
+ "SELECT v.tableoid, v.oid, v.varname,\n"
+ " v.varnamespace, v.vartype,\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n"
+ " CASE WHEN v.varcollation <> t.typcollation "
+ " THEN v.varcollation\n"
+ " ELSE 0\n"
+ " END AS varcollation,\n"
+ " v.varowner, v.varacl,\n"
+ " acldefault('V', v.varowner) AS acldefault\n"
+ "FROM pg_catalog.pg_variable v\n"
+ "JOIN pg_catalog.pg_type t "
+ "ON (v.vartype = t.oid)");
+
+ res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK);
+
+ ntups = PQntuples(res);
+
+ i_tableoid = PQfnumber(res, "tableoid");
+ i_oid = PQfnumber(res, "oid");
+ i_varname = PQfnumber(res, "varname");
+ i_varnamespace = PQfnumber(res, "varnamespace");
+ i_vartype = PQfnumber(res, "vartype");
+ i_vartypname = PQfnumber(res, "vartypname");
+ i_varcollation = PQfnumber(res, "varcollation");
+
+ i_varowner = PQfnumber(res, "varowner");
+ i_varacl = PQfnumber(res, "varacl");
+ i_acldefault = PQfnumber(res, "acldefault");
+
+ varinfo = pg_malloc(ntups * sizeof(VariableInfo));
+
+ for (i = 0; i < ntups; i++)
+ {
+ TypeInfo *vtype;
+
+ varinfo[i].dobj.objType = DO_VARIABLE;
+ varinfo[i].dobj.catId.tableoid =
+ atooid(PQgetvalue(res, i, i_tableoid));
+ varinfo[i].dobj.catId.oid = atooid(PQgetvalue(res, i, i_oid));
+ AssignDumpId(&varinfo[i].dobj);
+ varinfo[i].dobj.name = pg_strdup(PQgetvalue(res, i, i_varname));
+ varinfo[i].dobj.namespace =
+ findNamespace(atooid(PQgetvalue(res, i, i_varnamespace)));
+
+ varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype));
+ varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname));
+ varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
+
+ varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
+ varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
+ varinfo[i].dacl.privtype = 0;
+ varinfo[i].dacl.initprivs = NULL;
+ varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner));
+
+ /* do not try to dump ACL if no ACL exists */
+ if (!PQgetisnull(res, i, i_varacl))
+ varinfo[i].dobj.components |= DUMP_COMPONENT_ACL;
+
+ if (strlen(varinfo[i].rolname) == 0)
+ pg_log_warning("owner of variable \"%s\" appears to be invalid",
+ varinfo[i].dobj.name);
+
+ /* decide whether we want to dump it */
+ selectDumpableObject(&(varinfo[i].dobj), fout);
+
+ vtype = findTypeByOid(varinfo[i].vartype);
+ addObjectDependency(&varinfo[i].dobj, vtype->dobj.dumpId);
+ }
+ PQclear(res);
+
+ destroyPQExpBuffer(query);
+}
+
+/*
+ * dumpVariable
+ * dump the definition of the given session variable
+ */
+static void
+dumpVariable(Archive *fout, const VariableInfo *varinfo)
+{
+ DumpOptions *dopt = fout->dopt;
+
+ PQExpBuffer delq;
+ PQExpBuffer query;
+ char *qualvarname;
+ const char *vartypname;
+ Oid varcollation;
+
+ /* skip if not to be dumped */
+ if (!varinfo->dobj.dump || !dopt->dumpSchema)
+ return;
+
+ delq = createPQExpBuffer();
+ query = createPQExpBuffer();
+
+ qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
+ vartypname = varinfo->vartypname;
+ varcollation = varinfo->varcollation;
+
+ appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
+ qualvarname);
+
+ appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s",
+ qualvarname, vartypname);
+
+ if (OidIsValid(varcollation))
+ {
+ CollInfo *coll;
+
+ coll = findCollationByOid(varcollation);
+ if (coll)
+ appendPQExpBuffer(query, " COLLATE %s",
+ fmtQualifiedDumpable(coll));
+ }
+
+ appendPQExpBuffer(query, ";\n");
+
+ if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
+ ArchiveEntry(fout, varinfo->dobj.catId, varinfo->dobj.dumpId,
+ ARCHIVE_OPTS(.tag = varinfo->dobj.name,
+ .namespace = varinfo->dobj.namespace->dobj.name,
+ .owner = varinfo->rolname,
+ .description = "VARIABLE",
+ .section = SECTION_PRE_DATA,
+ .createStmt = query->data,
+ .dropStmt = delq->data));
+
+ /* dump comment if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_COMMENT)
+ dumpComment(fout, "VARIABLE", qualvarname,
+ NULL, varinfo->rolname,
+ varinfo->dobj.catId, 0, varinfo->dobj.dumpId);
+
+ /* dump ACL if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_ACL)
+ {
+ char *qvarname = pg_strdup(fmtId(varinfo->dobj.name));
+
+ dumpACL(fout, varinfo->dobj.dumpId, InvalidDumpId, "VARIABLE",
+ qvarname, NULL,
+ varinfo->dobj.namespace->dobj.name, NULL, varinfo->rolname,
+ &varinfo->dacl);
+
+ free(qvarname);
+ }
+
+ destroyPQExpBuffer(delq);
+ destroyPQExpBuffer(query);
+
+ free(qualvarname);
+}
+
static void
binary_upgrade_set_type_oids_by_type_oid(Archive *fout,
PQExpBuffer upgrade_buffer,
@@ -11156,6 +11339,9 @@ dumpDumpableObject(Archive *fout, DumpableObject *dobj)
case DO_REL_STATS:
dumpRelationStats(fout, (const RelStatsInfo *) dobj);
break;
+ case DO_VARIABLE:
+ dumpVariable(fout, (VariableInfo *) dobj);
+ break;
case DO_PRE_DATA_BOUNDARY:
case DO_POST_DATA_BOUNDARY:
/* never dumped, nothing to do */
@@ -15607,6 +15793,9 @@ dumpDefaultACL(Archive *fout, const DefaultACLInfo *daclinfo)
case DEFACLOBJ_NAMESPACE:
type = "SCHEMAS";
break;
+ case DEFACLOBJ_VARIABLE:
+ type = "VARIABLES";
+ break;
default:
/* shouldn't get here */
pg_fatal("unrecognized object type in default privileges: %d",
@@ -19329,6 +19518,7 @@ addBoundaryDependencies(DumpableObject **dobjs, int numObjs,
case DO_CONVERSION:
case DO_TABLE:
case DO_TABLE_ATTACH:
+ case DO_VARIABLE:
case DO_ATTRDEF:
case DO_PROCLANG:
case DO_CAST:
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index ca32f167878..d69806ce55c 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -53,6 +53,7 @@ typedef enum
DO_TABLE,
DO_TABLE_ATTACH,
DO_ATTRDEF,
+ DO_VARIABLE,
DO_INDEX,
DO_INDEX_ATTACH,
DO_STATSEXT,
@@ -730,6 +731,19 @@ typedef struct _SubRelInfo
char *srsublsn;
} SubRelInfo;
+/*
+ * The VariableInfo struct is used to represent session variables
+ */
+typedef struct _VariableInfo
+{
+ DumpableObject dobj;
+ DumpableAcl dacl;
+ Oid vartype;
+ char *vartypname;
+ Oid varcollation;
+ const char *rolname; /* name of owner, or empty string */
+} VariableInfo;
+
/*
* common utility functions
*/
@@ -813,5 +827,6 @@ extern void getPublicationTables(Archive *fout, TableInfo tblinfo[],
int numTables);
extern void getSubscriptions(Archive *fout);
extern void getSubscriptionTables(Archive *fout);
+extern void getVariables(Archive *fout);
#endif /* PG_DUMP_H */
diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c
index f75e9928bad..b4c2d07a02e 100644
--- a/src/bin/pg_dump/pg_dump_sort.c
+++ b/src/bin/pg_dump/pg_dump_sort.c
@@ -77,6 +77,7 @@ enum dbObjectTypePriorities
PRIO_DUMMY_TYPE,
PRIO_ATTRDEF,
PRIO_LARGE_OBJECT,
+ PRIO_VARIABLE,
PRIO_PRE_DATA_BOUNDARY, /* boundary! */
PRIO_TABLE_DATA,
PRIO_SEQUENCE_SET,
@@ -119,6 +120,7 @@ static const int dbObjectTypePriority[] =
[DO_TABLE] = PRIO_TABLE,
[DO_TABLE_ATTACH] = PRIO_TABLE_ATTACH,
[DO_ATTRDEF] = PRIO_ATTRDEF,
+ [DO_VARIABLE] = PRIO_VARIABLE,
[DO_INDEX] = PRIO_INDEX,
[DO_INDEX_ATTACH] = PRIO_INDEX_ATTACH,
[DO_STATSEXT] = PRIO_STATSEXT,
@@ -1533,6 +1535,11 @@ describeDumpableObject(DumpableObject *obj, char *buf, int bufsize)
"RELATION STATISTICS FOR %s (ID %d OID %u)",
obj->name, obj->dumpId, obj->catId.oid);
return;
+ case DO_VARIABLE:
+ snprintf(buf, bufsize,
+ "VARIABLE %s (ID %d OID %u)",
+ obj->name, obj->dumpId, obj->catId.oid);
+ return;
}
/* shouldn't get here */
snprintf(buf, bufsize,
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index c7bffc1b045..87dbbc9abdb 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -883,6 +883,16 @@ my %tests = (
unlike => { no_privs => 1, },
},
+ 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC'
+ => {
+ create_order => 56,
+ create_sql => 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;',
+ regexp => qr/^
+ \QALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;\E/xm,
+ like => { %full_runs, section_post_data => 1, },
+ unlike => { no_privs => 1, },
+ },
+
'ALTER ROLE regress_dump_test_role' => {
regexp => qr/^
\QALTER ROLE regress_dump_test_role WITH \E
@@ -1773,6 +1783,23 @@ my %tests = (
},
},
+ 'COMMENT ON VARIABLE dump_test.variable1' => {
+ create_order => 71,
+ create_sql => 'COMMENT ON VARIABLE dump_test.variable1
+ IS \'comment on variable\';',
+ regexp =>
+ qr/^\QCOMMENT ON VARIABLE dump_test.variable1 IS 'comment on variable';\E/m,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'COPY test_table' => {
create_order => 4,
create_sql => 'INSERT INTO dump_test.test_table (col1) '
@@ -4066,6 +4093,24 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable1 AS integer;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable1 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
@@ -4529,6 +4574,25 @@ my %tests = (
like => {},
},
+ 'GRANT SELECT ON VARIABLE dump_test.variable1' => {
+ create_order => 73,
+ create_sql =>
+ 'GRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;',
+ regexp => qr/^
+ \QGRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;\E
+ /xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ no_privs => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'REFRESH MATERIALIZED VIEW matview' => {
regexp => qr/^\QREFRESH MATERIALIZED VIEW dump_test.matview;\E/m,
like =>
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 0f27bf7a91f..078eaad4e36 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -1243,6 +1243,9 @@ exec_command_d(PsqlScanState scan_state, bool active_branch, const char *cmd)
break;
}
break;
+ case 'V': /* Variables */
+ success = listVariables(pattern, show_verbose);
+ break;
case 'x': /* Extensions */
if (show_verbose)
success = listExtensionContents(pattern);
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..783cbb9cd11 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -1222,7 +1222,7 @@ listDefaultACLs(const char *pattern)
printfPQExpBuffer(&buf,
"SELECT pg_catalog.pg_get_userbyid(d.defaclrole) AS \"%s\",\n"
" n.nspname AS \"%s\",\n"
- " CASE d.defaclobjtype WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
+ " CASE d.defaclobjtype WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
" ",
gettext_noop("Owner"),
gettext_noop("Schema"),
@@ -1236,6 +1236,8 @@ listDefaultACLs(const char *pattern)
gettext_noop("type"),
DEFACLOBJ_NAMESPACE,
gettext_noop("schema"),
+ DEFACLOBJ_VARIABLE,
+ gettext_noop("session variable"),
gettext_noop("Type"));
printACLColumn(&buf, "d.defaclacl");
@@ -5318,6 +5320,102 @@ error_return:
return false;
}
+/*
+ * \dV
+ *
+ * listVariables()
+ */
+bool
+listVariables(const char *pattern, bool verbose)
+{
+ PQExpBufferData buf;
+ PGresult *res;
+ printQueryOpt myopt = pset.popt;
+ static const bool translate_columns[] = {false, false, false, false, false, false, false};
+
+ if (pset.sversion < 180000)
+ {
+ char sverbuf[32];
+
+ pg_log_error("The server (version %s) does not support session variables.",
+ formatPGVersionNumber(pset.sversion, false,
+ sverbuf, sizeof(sverbuf)));
+ return true;
+ }
+
+ initPQExpBuffer(&buf);
+
+ printfPQExpBuffer(&buf,
+ "SELECT n.nspname as \"%s\",\n"
+ " v.varname as \"%s\",\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n"
+ " (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
+ " WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
+ " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n",
+ gettext_noop("Schema"),
+ gettext_noop("Name"),
+ gettext_noop("Type"),
+ gettext_noop("Collation"),
+ gettext_noop("Owner"));
+
+ if (verbose)
+ {
+ appendPQExpBufferStr(&buf, ",\n ");
+ printACLColumn(&buf, "v.varacl");
+ appendPQExpBuffer(&buf,
+ ",\n pg_catalog.obj_description(v.oid, 'pg_variable') AS \"%s\"",
+ gettext_noop("Description"));
+ }
+
+ appendPQExpBufferStr(&buf,
+ "\nFROM pg_catalog.pg_variable v"
+ "\n LEFT JOIN pg_catalog.pg_namespace n ON n.oid = v.varnamespace");
+
+ appendPQExpBufferStr(&buf, "\nWHERE true\n");
+ if (!pattern)
+ appendPQExpBufferStr(&buf, " AND n.nspname <> 'pg_catalog'\n"
+ " AND n.nspname <> 'information_schema'\n");
+
+ if (!validateSQLNamePattern(&buf, pattern, true, false,
+ "n.nspname", "v.varname", NULL,
+ "pg_catalog.pg_variable_is_visible(v.oid)",
+ NULL, 3))
+ return false;
+
+ appendPQExpBufferStr(&buf, "ORDER BY 1,2;");
+
+ res = PSQLexec(buf.data);
+ termPQExpBuffer(&buf);
+ if (!res)
+ return false;
+
+ /*
+ * Most functions in this file are content to print an empty table when
+ * there are no matching objects. We intentionally deviate from that
+ * here, but only in !quiet mode, for historical reasons.
+ */
+ if (PQntuples(res) == 0 && !pset.quiet)
+ {
+ if (pattern)
+ pg_log_error("Did not find any session variable named \"%s\".",
+ pattern);
+ else
+ pg_log_error("Did not find any session variables.");
+ }
+ else
+ {
+ myopt.nullPrint = NULL;
+ myopt.title = _("List of variables");
+ myopt.translate_header = true;
+ myopt.translate_columns = translate_columns;
+ myopt.n_translate_columns = lengthof(translate_columns);
+
+ printQuery(res, &myopt, pset.queryFout, false, pset.logfile);
+ }
+
+ PQclear(res);
+ return true;
+}
/*
* \dFp
diff --git a/src/bin/psql/describe.h b/src/bin/psql/describe.h
index 18ecaa60949..55ced4aab7b 100644
--- a/src/bin/psql/describe.h
+++ b/src/bin/psql/describe.h
@@ -149,4 +149,7 @@ extern bool listOpFamilyFunctions(const char *access_method_pattern,
/* \dl or \lo_list */
extern bool listLargeObjects(bool verbose);
+/* \dV */
+extern bool listVariables(const char *pattern, bool varbose);
+
#endif /* DESCRIBE_H */
diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index 714b8619233..ee659d6055b 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -273,6 +273,7 @@ slashUsage(unsigned short int pager)
HELP0(" \\dT[Sx+] [PATTERN] list data types\n");
HELP0(" \\du[Sx+] [PATTERN] list roles\n");
HELP0(" \\dv[Sx+] [PATTERN] list views\n");
+ HELP0(" \\dV[x+] [PATTERN] list session variables\n");
HELP0(" \\dx[x+] [PATTERN] list extensions\n");
HELP0(" \\dX[x] [PATTERN] list extended statistics\n");
HELP0(" \\dy[x+] [PATTERN] list event triggers\n");
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 8432be641ac..84907f76c0a 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -970,6 +970,13 @@ static const SchemaQuery Query_for_trigger_of_table = {
.refnamespace = "c1.relnamespace",
};
+static const SchemaQuery Query_for_list_of_variables = {
+ .min_server_version = 180000,
+ .catname = "pg_catalog.pg_variable v",
+ .viscondition = "pg_catalog.pg_variable_is_visible(v.oid)",
+ .namespace = "v.varnamespace",
+ .result = "v.varname",
+};
/*
* Queries to get lists of names of various kinds of things, possibly
@@ -1318,6 +1325,7 @@ static const pgsql_thing_t words_after_create[] = {
* TABLE ... */
{"USER", Query_for_list_of_roles, NULL, NULL, Keywords_for_user_thing},
{"USER MAPPING FOR", NULL, NULL, NULL},
+ {"VARIABLE", NULL, NULL, &Query_for_list_of_variables},
{"VIEW", NULL, NULL, &Query_for_list_of_views},
{NULL} /* end of list */
};
@@ -1883,7 +1891,7 @@ psql_completion(const char *text, int start, int end)
"\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL",
"\\dm", "\\dn", "\\do", "\\dO", "\\dp", "\\dP", "\\dPi", "\\dPt",
"\\drds", "\\drg", "\\dRs", "\\dRp", "\\ds",
- "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy",
+ "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy", "\\dV",
"\\echo", "\\edit", "\\ef", "\\elif", "\\else", "\\encoding",
"\\endif", "\\endpipeline", "\\errverbose", "\\ev",
"\\f", "\\flush", "\\flushrequest",
@@ -2585,6 +2593,9 @@ match_previous_words(int pattern_id,
"ALL");
else if (Matches("ALTER", "SYSTEM", "SET", MatchAny))
COMPLETE_WITH("TO");
+ /* ALTER VARIABLE <name> */
+ else if (Matches("ALTER", "VARIABLE", MatchAny))
+ COMPLETE_WITH("OWNER TO", "RENAME TO", "SET SCHEMA");
/* ALTER VIEW <name> */
else if (Matches("ALTER", "VIEW", MatchAny))
COMPLETE_WITH("ALTER COLUMN", "OWNER TO", "RENAME", "RESET", "SET");
@@ -3165,7 +3176,7 @@ match_previous_words(int pattern_id,
"ROUTINE", "RULE", "SCHEMA", "SEQUENCE", "SERVER",
"STATISTICS", "SUBSCRIPTION", "TABLE",
"TABLESPACE", "TEXT SEARCH", "TRANSFORM FOR",
- "TRIGGER", "TYPE", "VIEW");
+ "TRIGGER", "TYPE", "VARIABLE", "VIEW");
else if (Matches("COMMENT", "ON", "ACCESS", "METHOD"))
COMPLETE_WITH_QUERY(Query_for_list_of_access_methods);
else if (Matches("COMMENT", "ON", "CONSTRAINT"))
@@ -3975,6 +3986,13 @@ match_previous_words(int pattern_id,
else if (TailMatches("=", MatchAnyExcept("*)")))
COMPLETE_WITH(",", ")");
}
+/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
+ /* Complete CREATE VARIABLE <name> with AS */
+ else if (TailMatches("CREATE", "VARIABLE", MatchAny))
+ COMPLETE_WITH("AS");
+ else if (TailMatches("VARIABLE", MatchAny, "AS"))
+ /* Complete CREATE VARIABLE <name> with AS types */
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
/* CREATE VIEW --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE [ OR REPLACE ] VIEW <name> with AS or WITH */
@@ -4252,6 +4270,12 @@ match_previous_words(int pattern_id,
else if (Matches("DROP", "TRANSFORM", "FOR", MatchAny, "LANGUAGE", MatchAny))
COMPLETE_WITH("CASCADE", "RESTRICT");
+ /* DROP VARIABLE */
+ else if (Matches("DROP", "VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ else if (Matches("DROP", "VARIABLE", MatchAny))
+ COMPLETE_WITH("CASCADE", "RESTRICT");
+
/* EXECUTE */
else if (Matches("EXECUTE"))
COMPLETE_WITH_QUERY(Query_for_list_of_prepared_statements);
@@ -4453,7 +4477,7 @@ match_previous_words(int pattern_id,
* objects supported.
*/
if (HeadMatches("ALTER", "DEFAULT", "PRIVILEGES"))
- COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS");
+ COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS", "VARIABLES");
else
COMPLETE_WITH_SCHEMA_QUERY_PLUS(Query_for_list_of_grantables,
"ALL FUNCTIONS IN SCHEMA",
@@ -4461,6 +4485,7 @@ match_previous_words(int pattern_id,
"ALL ROUTINES IN SCHEMA",
"ALL SEQUENCES IN SCHEMA",
"ALL TABLES IN SCHEMA",
+ "ALL VARIABLES IN SCHEMA",
"DATABASE",
"DOMAIN",
"FOREIGN DATA WRAPPER",
@@ -4475,7 +4500,8 @@ match_previous_words(int pattern_id,
"SEQUENCE",
"TABLE",
"TABLESPACE",
- "TYPE");
+ "TYPE",
+ "VARIABLE");
}
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "ALL") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "ALL"))
@@ -4483,7 +4509,8 @@ match_previous_words(int pattern_id,
"PROCEDURES IN SCHEMA",
"ROUTINES IN SCHEMA",
"SEQUENCES IN SCHEMA",
- "TABLES IN SCHEMA");
+ "TABLES IN SCHEMA",
+ "VARIABLES IN SCHEMA");
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "FOREIGN") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "FOREIGN"))
COMPLETE_WITH("DATA WRAPPER", "SERVER");
@@ -4519,6 +4546,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_tablespaces);
else if (TailMatches("TYPE"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
+ else if (TailMatches("VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatches("GRANT", MatchAny, MatchAny, MatchAny))
COMPLETE_WITH("TO");
else
@@ -4821,7 +4850,7 @@ match_previous_words(int pattern_id,
/* PREPARE xx AS */
else if (Matches("PREPARE", MatchAny, "AS"))
- COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM");
+ COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM", "LET");
/*
* PREPARE TRANSACTION is missing on purpose. It's intended for transaction
@@ -5305,6 +5334,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_roles);
else if (TailMatchesCS("\\dv*"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_views);
+ else if (TailMatchesCS("\\dV*"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatchesCS("\\dx*"))
COMPLETE_WITH_QUERY(Query_for_list_of_extensions);
else if (TailMatchesCS("\\dX*"))
diff --git a/src/include/catalog/Makefile b/src/include/catalog/Makefile
index 2bbc7805fe3..f98760de635 100644
--- a/src/include/catalog/Makefile
+++ b/src/include/catalog/Makefile
@@ -81,7 +81,8 @@ CATALOG_HEADERS := \
pg_publication_namespace.h \
pg_publication_rel.h \
pg_subscription.h \
- pg_subscription_rel.h
+ pg_subscription_rel.h \
+ pg_variable.h
GENERATED_HEADERS := $(CATALOG_HEADERS:%.h=%_d.h)
diff --git a/src/include/catalog/meson.build b/src/include/catalog/meson.build
index ec1cf467f6f..81398efa7c9 100644
--- a/src/include/catalog/meson.build
+++ b/src/include/catalog/meson.build
@@ -69,6 +69,7 @@ catalog_headers = [
'pg_publication_rel.h',
'pg_subscription.h',
'pg_subscription_rel.h',
+ 'pg_variable.h',
]
# The .dat files we need can just be listed alphabetically.
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index 8c7ccc69a3c..bdac0c13bec 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -97,6 +97,8 @@ extern Oid TypenameGetTypid(const char *typname);
extern Oid TypenameGetTypidExtended(const char *typname, bool temp_ok);
extern bool TypeIsVisible(Oid typid);
+extern bool VariableIsVisible(Oid varid);
+
extern FuncCandidateList FuncnameGetCandidates(List *names,
int nargs, List *argnames,
bool expand_variadic,
@@ -169,6 +171,10 @@ extern SearchPathMatcher *GetSearchPathMatcher(MemoryContext context);
extern SearchPathMatcher *CopySearchPathMatcher(SearchPathMatcher *path);
extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
+extern List *NamesFromList(List *names);
+extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
+extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
extern Oid FindDefaultConversionProc(int32 for_encoding, int32 to_encoding);
diff --git a/src/include/catalog/pg_default_acl.h b/src/include/catalog/pg_default_acl.h
index 728024b1fa7..5f94424a684 100644
--- a/src/include/catalog/pg_default_acl.h
+++ b/src/include/catalog/pg_default_acl.h
@@ -68,6 +68,7 @@ MAKE_SYSCACHE(DEFACLROLENSPOBJ, pg_default_acl_role_nsp_obj_index, 8);
#define DEFACLOBJ_FUNCTION 'f' /* function */
#define DEFACLOBJ_TYPE 'T' /* type */
#define DEFACLOBJ_NAMESPACE 'n' /* namespace */
+#define DEFACLOBJ_VARIABLE 'V' /* variable */
#endif /* EXPOSE_TO_CLIENT_CODE */
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index cd9422d0bac..2b06d9475b5 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5404,6 +5404,26 @@
prorettype => 'bool', proargtypes => 'oid oid text',
prosrc => 'has_largeobject_privilege_id_id' },
+{ oid => '9613', descr => 'user privilege on session variable by username, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name text text',
+ prosrc => 'has_session_variable_privilege_name_name' },
+{ oid => '9614', descr => 'user privilege on session variable by username, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name oid text', prosrc => 'has_session_variable_privilege_name_id' },
+{ oid => '9615', descr => 'user privilege on session variable by user oid, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text text', prosrc => 'has_session_variable_privilege_id_name' },
+{ oid => '9616', descr => 'user privilege on session variable by user oid, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid oid text', prosrc => 'has_session_variable_privilege_id_id' },
+{ oid => '9617', descr => 'current user privilege on session variable by seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'text text', prosrc => 'has_session_variable_privilege_name' },
+{ oid => '9618', descr => 'current user privilege on session variable by seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text', prosrc => 'has_session_variable_privilege_id' },
+
{ oid => '3355', descr => 'I/O',
proname => 'pg_ndistinct_in', prorettype => 'pg_ndistinct',
proargtypes => 'cstring', prosrc => 'pg_ndistinct_in' },
@@ -6604,6 +6624,9 @@
proname => 'pg_collation_is_visible', procost => '10', provolatile => 's',
prorettype => 'bool', proargtypes => 'oid',
prosrc => 'pg_collation_is_visible' },
+{ oid => '9999', descr => 'is session variable visible in search path?',
+ proname => 'pg_variable_is_visible', procost => '10', provolatile => 's',
+ prorettype => 'bool', proargtypes => 'oid', prosrc => 'pg_variable_is_visible' },
{ oid => '2854', descr => 'get OID of current session\'s temp schema, if any',
proname => 'pg_my_temp_schema', provolatile => 's', proparallel => 'r',
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
new file mode 100644
index 00000000000..3d3c6eb24b5
--- /dev/null
+++ b/src/include/catalog/pg_variable.h
@@ -0,0 +1,81 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.h
+ * definition of session variables system catalog (pg_variables)
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/catalog/pg_variable.h
+ *
+ * NOTES
+ * The Catalog.pm module reads this file and derives schema
+ * information.
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_VARIABLE_H
+#define PG_VARIABLE_H
+
+#include "catalog/genbki.h"
+#include "catalog/objectaddress.h"
+#include "catalog/pg_variable_d.h"
+#include "utils/acl.h"
+
+/* ----------------
+ * pg_variable definition. cpp turns this into
+ * typedef struct FormData_pg_variable
+ * ----------------
+ */
+CATALOG(pg_variable,9222,VariableRelationId)
+{
+ Oid oid; /* oid */
+
+ /* OID of entry in pg_type for variable's type */
+ Oid vartype BKI_LOOKUP(pg_type);
+
+ /* variable name */
+ NameData varname;
+
+ /* OID of namespace containing variable class */
+ Oid varnamespace BKI_LOOKUP(pg_namespace);
+
+ /* variable owner */
+ Oid varowner BKI_LOOKUP(pg_authid);
+
+ /* typmod for variable's type */
+ int32 vartypmod BKI_DEFAULT(-1);
+
+ /* variable collation */
+ Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation);
+
+
+#ifdef CATALOG_VARLEN /* variable-length fields start here */
+
+ /* access permissions */
+ aclitem varacl[1] BKI_DEFAULT(_null_);
+
+#endif
+} FormData_pg_variable;
+
+/* ----------------
+ * Form_pg_variable corresponds to a pointer to a tuple with
+ * the format of the pg_variable relation.
+ * ----------------
+ */
+typedef FormData_pg_variable *Form_pg_variable;
+
+DECLARE_TOAST(pg_variable, 9223, 9224);
+
+DECLARE_UNIQUE_INDEX_PKEY(pg_variable_oid_index, 9225, VariableOidIndexId, pg_variable, btree(oid oid_ops));
+DECLARE_UNIQUE_INDEX(pg_variable_varname_nsp_index, 9226, VariableNameNspIndexId, pg_variable, btree(varname name_ops, varnamespace oid_ops));
+
+extern ObjectAddress CreateVariable(ParseState *pstate,
+ CreateSessionVarStmt *stmt);
+extern void DropVariableById(Oid varid);
+
+MAKE_SYSCACHE(VARIABLENAMENSP, pg_variable_varname_nsp_index, 8);
+MAKE_SYSCACHE(VARIABLEOID, pg_variable_oid_index, 8);
+
+#endif /* PG_VARIABLE_H */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 0b208f51bdd..9858034ccf6 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2360,6 +2360,7 @@ typedef enum ObjectType
OBJECT_TSTEMPLATE,
OBJECT_TYPE,
OBJECT_USER_MAPPING,
+ OBJECT_VARIABLE,
OBJECT_VIEW,
} ObjectType;
@@ -3506,6 +3507,21 @@ typedef struct AlterStatsStmt
bool missing_ok; /* skip error if statistics object is missing */
} AlterStatsStmt;
+
+/* ----------------------
+ * {Create|Alter} VARIABLE Statement
+ * ----------------------
+ */
+typedef struct CreateSessionVarStmt
+{
+ NodeTag type;
+ RangeVar *variable; /* the variable to create */
+ TypeName *typeName; /* the type of variable */
+ CollateClause *collClause;
+ bool if_not_exists; /* do nothing if it already exists */
+} CreateSessionVarStmt;
+
+
/* ----------------------
* Create Function Statement
* ----------------------
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 40cf090ce61..793ace526df 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -485,6 +485,8 @@ PG_KEYWORD("validator", VALIDATOR, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("value", VALUE_P, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("values", VALUES, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("varchar", VARCHAR, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variable", VARIABLE, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variables", VARIABLES, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("variadic", VARIADIC, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("varying", VARYING, UNRESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("verbose", VERBOSE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index d250a714d59..ea86954dded 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -68,6 +68,7 @@ PG_CMDTAG(CMDTAG_ALTER_TRANSFORM, "ALTER TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TRIGGER, "ALTER TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TYPE, "ALTER TYPE", true, true, false)
PG_CMDTAG(CMDTAG_ALTER_USER_MAPPING, "ALTER USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_ALTER_VARIABLE, "ALTER VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_VIEW, "ALTER VIEW", true, false, false)
PG_CMDTAG(CMDTAG_ANALYZE, "ANALYZE", false, false, false)
PG_CMDTAG(CMDTAG_BEGIN, "BEGIN", false, false, false)
@@ -123,6 +124,7 @@ PG_CMDTAG(CMDTAG_CREATE_TRANSFORM, "CREATE TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TRIGGER, "CREATE TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TYPE, "CREATE TYPE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_USER_MAPPING, "CREATE USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_CREATE_VARIABLE, "CREATE VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_VIEW, "CREATE VIEW", true, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE, "DEALLOCATE", false, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE_ALL, "DEALLOCATE ALL", false, false, false)
@@ -175,6 +177,7 @@ PG_CMDTAG(CMDTAG_DROP_TRANSFORM, "DROP TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TRIGGER, "DROP TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TYPE, "DROP TYPE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_USER_MAPPING, "DROP USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_DROP_VARIABLE, "DROP VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_VIEW, "DROP VIEW", true, false, false)
PG_CMDTAG(CMDTAG_EXECUTE, "EXECUTE", false, false, false)
PG_CMDTAG(CMDTAG_EXPLAIN, "EXPLAIN", false, false, false)
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index 01ae5b719fd..5e1a8a82e90 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -169,6 +169,7 @@ typedef struct ArrayType Acl;
#define ACL_ALL_RIGHTS_SCHEMA (ACL_USAGE|ACL_CREATE)
#define ACL_ALL_RIGHTS_TABLESPACE (ACL_CREATE)
#define ACL_ALL_RIGHTS_TYPE (ACL_USAGE)
+#define ACL_ALL_RIGHTS_VARIABLE (ACL_SELECT|ACL_UPDATE)
/* operation codes for pg_*_aclmask */
typedef enum
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 6fab7aa6009..9503b528647 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -135,6 +135,7 @@ extern char get_func_prokind(Oid funcid);
extern bool get_func_leakproof(Oid funcid);
extern RegProcedure get_func_support(Oid funcid);
extern Oid get_relname_relid(const char *relname, Oid relnamespace);
+extern Oid get_varname_varid(const char *varname, Oid varnamespace);
extern char *get_rel_name(Oid relid);
extern Oid get_rel_namespace(Oid relid);
extern Oid get_rel_type_id(Oid relid);
@@ -207,6 +208,14 @@ extern char *get_publication_name(Oid pubid, bool missing_ok);
extern Oid get_subscription_oid(const char *subname, bool missing_ok);
extern char *get_subscription_name(Oid subid, bool missing_ok);
+extern char *get_session_variable_name(Oid varid);
+extern Oid get_session_variable_namespace(Oid varid);
+extern Oid get_session_variable_type(Oid varid);
+extern void get_session_variable_type_typmod_collid(Oid varid,
+ Oid *typid,
+ int32 *typmod,
+ Oid *collid);
+
#define type_is_array(typid) (get_element_type(typid) != InvalidOid)
/* type_is_array_domain accepts both plain arrays and domains over arrays */
#define type_is_array_domain(typid) (get_base_element_type(typid) != InvalidOid)
diff --git a/src/test/regress/expected/dependency.out b/src/test/regress/expected/dependency.out
index 75a078ada9e..cd8e4412fa9 100644
--- a/src/test/regress/expected/dependency.out
+++ b/src/test/regress/expected/dependency.out
@@ -151,3 +151,20 @@ owner of type deptest_t
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+-- should fail
+DROP DOMAIN vardomain;
+ERROR: cannot drop type vardomain because other objects depend on it
+DETAIL: column c of composite type vartype depends on type vardomain
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP TYPE vartype;
+ERROR: cannot drop type vartype because other objects depend on it
+DETAIL: session variable var1 depends on type vartype
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/expected/oidjoins.out b/src/test/regress/expected/oidjoins.out
index 215eb899be3..d9953321402 100644
--- a/src/test/regress/expected/oidjoins.out
+++ b/src/test/regress/expected/oidjoins.out
@@ -266,3 +266,7 @@ NOTICE: checking pg_subscription {subdbid} => pg_database {oid}
NOTICE: checking pg_subscription {subowner} => pg_authid {oid}
NOTICE: checking pg_subscription_rel {srsubid} => pg_subscription {oid}
NOTICE: checking pg_subscription_rel {srrelid} => pg_class {oid}
+NOTICE: checking pg_variable {vartype} => pg_type {oid}
+NOTICE: checking pg_variable {varnamespace} => pg_namespace {oid}
+NOTICE: checking pg_variable {varowner} => pg_authid {oid}
+NOTICE: checking pg_variable {varcollation} => pg_collation {oid}
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 6543e90de75..65d8847e60a 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6021,6 +6021,30 @@ COMMIT;
# final ON_ERROR_ROLLBACK: off
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | |
+(1 row)
+
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | =r/regress_variable_owner |
+(1 row)
+
+DROP VARIABLE var1;
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
-- check describing invalid multipart names
\dA regression.heap
improper qualified name (too many dotted names): regression.heap
@@ -6242,6 +6266,12 @@ cross-database references are not implemented: nonesuch.public.func_deps_stat
improper qualified name (too many dotted names): regression.myevt
\dy nonesuch.myevt
improper qualified name (too many dotted names): nonesuch.myevt
+\dV host.regression.public.var
+improper qualified name (too many dotted names): host.regression.public.var
+\dV regression|mydb.public.var
+cross-database references are not implemented: regression|mydb.public.var
+\dV nonesuch.public.var
+cross-database references are not implemented: nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
List of access methods
@@ -6476,6 +6506,12 @@ List of schemas
------+-------+-------+---------+----------+------
(0 rows)
+\dV "no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
improper qualified name (too many dotted names): "no.such.schema"."no.such.access.method"
@@ -6645,6 +6681,12 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
List of tables
@@ -6778,6 +6820,12 @@ List of text search templates
--------+------+------------+-----------+--------------+-----
(0 rows)
+\dV regression."no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -6825,6 +6873,8 @@ cross-database references are not implemented: "no.such.database"."no.such.schem
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
+cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
CREATE ROLE regress_du_role1;
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
new file mode 100644
index 00000000000..c36660ce6d3
--- /dev/null
+++ b/src/test/regress/expected/session_variables.out
@@ -0,0 +1,433 @@
+CREATE ROLE regress_variable_owner;
+SET log_statement TO ddl;
+-- should be ok
+CREATE VARIABLE var1 AS int;
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+ERROR: session variable cannot be pseudo-type anyelement
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+NOTICE: session variable "var2" does not exist, skipping
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+NOTICE: session variable "var1" already exists, skipping
+-- should fail
+CREATE VARIABLE var1 AS int;
+ERROR: session variable "var1" already exists
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TABLE t1;
+ERROR: cannot drop table t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+ERROR: cannot alter table "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TABLE t1;
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TYPE t1;
+ERROR: cannot drop type t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+ERROR: cannot alter type "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TYPE t1;
+SET log_statement TO default;
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+CREATE VARIABLE var1 AS testvar_domain;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter domain "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS testvar_type;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter type "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+NOTICE: NORMAL: orig=t normal=f istemp=f type=session variable identity=public.var1 name={public,var1} args={}
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+ obj_description
+-----------------------
+ some variable comment
+(1 row)
+
+DROP VARIABLE var1;
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+ varname | descr | type | object_names | object_args | ident
+---------------+-----------------------------------------+------------------+--------------------------+-------------+--------------------------------------------------------------------
+ svartest_var1 | session variable vartest1.svartest_var1 | session variable | {vartest1,svartest_var1} | {} | ("session variable",vartest1,svartest_var1,vartest1.svartest_var1)
+ svartest_var1 | session variable vartest2.svartest_var1 | session variable | {vartest2,svartest_var1} | {} | ("session variable",vartest2,svartest_var1,vartest2.svartest_var1)
+(2 rows)
+
+DROP SCHEMA vartest1 CASCADE;
+NOTICE: drop cascades to session variable vartest1.svartest_var1
+DROP SCHEMA vartest2 CASCADE;
+NOTICE: drop cascades to session variable vartest2.svartest_var1
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE ROLE regress_variable_reader;
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+DROP VARIABLE public.varxx;
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE public.var1 AS int;
+SET search_path TO public;
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+SET ROLE TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+--
+-- end of function has_session_variable_privilege tests.
+--
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+DROP VARIABLE public.var1;
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+DROP ROLE regress_variable_owner;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 37b6d21e1f9..4f136fb4745 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -111,7 +111,7 @@ test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath sqljson
# NB: temp.sql does a reconnect which transiently uses 2 connections,
# so keep this parallel group to at most 19 tests
# ----------
-test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml
+test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml session_variables
# ----------
# Another group of parallel tests
diff --git a/src/test/regress/sql/dependency.sql b/src/test/regress/sql/dependency.sql
index 8d74ed7122c..6c18b7f840a 100644
--- a/src/test/regress/sql/dependency.sql
+++ b/src/test/regress/sql/dependency.sql
@@ -114,3 +114,17 @@ DROP USER regress_dep_user2;
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+
+-- should fail
+DROP DOMAIN vardomain;
+DROP TYPE vartype;
+
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index 97d1be3aac3..6e0056dc5d6 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -1642,6 +1642,19 @@ COMMIT;
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+DROP VARIABLE var1;
+
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
+
-- check describing invalid multipart names
\dA regression.heap
\dA nonesuch.heap
@@ -1753,6 +1766,9 @@ DROP FUNCTION psql_error;
\dX nonesuch.public.func_deps_stat
\dy regression.myevt
\dy nonesuch.myevt
+\dV host.regression.public.var
+\dV regression|mydb.public.var
+\dV nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
@@ -1794,6 +1810,8 @@ DROP FUNCTION psql_error;
\dx "no.such.installed.extension"
\dX "no.such.extended.statistics"
\dy "no.such.event.trigger"
+\dV "no.such.variable"
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
@@ -1834,6 +1852,7 @@ DROP FUNCTION psql_error;
\dx "no.such.schema"."no.such.installed.extension"
\dX "no.such.schema"."no.such.extended.statistics"
\dy "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
@@ -1858,6 +1877,7 @@ DROP FUNCTION psql_error;
\dP regression."no.such.schema"."no.such.partitioned.relation"
\dT regression."no.such.schema"."no.such.data.type"
\dX regression."no.such.schema"."no.such.extended.statistics"
+\dV regression."no.such.schema"."no.such.variable"
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -1883,6 +1903,7 @@ DROP FUNCTION psql_error;
\dP "no.such.database"."no.such.schema"."no.such.partitioned.relation"
\dT "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
new file mode 100644
index 00000000000..eeb0f94ca3c
--- /dev/null
+++ b/src/test/regress/sql/session_variables.sql
@@ -0,0 +1,297 @@
+CREATE ROLE regress_variable_owner;
+
+SET log_statement TO ddl;
+
+-- should be ok
+CREATE VARIABLE var1 AS int;
+
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+
+-- should fail
+CREATE VARIABLE var1 AS int;
+
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TABLE t1;
+
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TABLE t1;
+
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TYPE t1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+SET log_statement TO default;
+
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+
+CREATE VARIABLE var1 AS testvar_domain;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+CREATE VARIABLE var1 AS testvar_type;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+
+DROP VARIABLE var1;
+
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+
+DROP SCHEMA vartest1 CASCADE;
+DROP SCHEMA vartest2 CASCADE;
+
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+
+CREATE ROLE regress_variable_reader;
+
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+
+DROP VARIABLE public.varxx;
+
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE public.var1 AS int;
+
+SET search_path TO public;
+
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+
+SET ROLE TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+--
+-- end of function has_session_variable_privilege tests.
+--
+
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+
+DROP VARIABLE public.var1;
+
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+
+DROP ROLE regress_variable_owner;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 56989aa0b84..7a3297d692d 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -546,6 +546,7 @@ CreateRoleStmt
CreateSchemaStmt
CreateSchemaStmtContext
CreateSeqStmt
+CreateSessionVarStmt
CreateStatsStmt
CreateStmt
CreateStmtContext
@@ -886,6 +887,7 @@ FormData_pg_ts_parser
FormData_pg_ts_template
FormData_pg_type
FormData_pg_user_mapping
+FormData_pg_variable
FormExtraData_pg_attribute
Form_pg_aggregate
Form_pg_am
@@ -945,6 +947,7 @@ Form_pg_ts_parser
Form_pg_ts_template
Form_pg_type
Form_pg_user_mapping
+Form_pg_variable
FormatNode
FreeBlockNumberArray
FreeListData
@@ -3121,6 +3124,7 @@ VarString
VarStringSortSupport
Variable
VariableAssignHook
+VariableInfo
VariableSetKind
VariableSetStmt
VariableShowStmt
--
2.48.1
[text/x-patch] v20250301-0004-DISCARD-VARIABLES.patch (9.6K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/5-v20250301-0004-DISCARD-VARIABLES.patch)
download | inline diff:
From 369e477f9dd8b430db1b3ea86619c338e47ee96e Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sun, 28 Jan 2024 20:54:20 +0100
Subject: [PATCH 04/21] DISCARD VARIABLES
Implementation of DISCARD VARIABLES commands by removing hash table with session variables
and resetting related memory context.
---
doc/src/sgml/ref/discard.sgml | 13 +++-
src/backend/commands/discard.c | 6 ++
src/backend/commands/session_variable.c | 28 ++++++++-
src/backend/parser/gram.y | 6 ++
src/backend/tcop/utility.c | 3 +
src/bin/psql/tab-complete.in.c | 2 +-
src/include/commands/session_variable.h | 2 +
src/include/nodes/parsenodes.h | 1 +
src/include/tcop/cmdtaglist.h | 1 +
.../regress/expected/session_variables.out | 63 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 36 +++++++++++
11 files changed, 158 insertions(+), 3 deletions(-)
diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
index bf44c523cac..61b967f9c9b 100644
--- a/doc/src/sgml/ref/discard.sgml
+++ b/doc/src/sgml/ref/discard.sgml
@@ -21,7 +21,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
+DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES }
</synopsis>
</refsynopsisdiv>
@@ -66,6 +66,16 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>VARIABLES</literal></term>
+ <listitem>
+ <para>
+ Resets the value of all session variables. If a variable
+ is later reused, it is re-initialized to <literal>NULL</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><literal>TEMPORARY</literal> or <literal>TEMP</literal></term>
<listitem>
@@ -93,6 +103,7 @@ SELECT pg_advisory_unlock_all();
DISCARD PLANS;
DISCARD TEMP;
DISCARD SEQUENCES;
+DISCARD VARIABLES;
</programlisting></para>
</listitem>
</varlistentry>
diff --git a/src/backend/commands/discard.c b/src/backend/commands/discard.c
index 81339a75a52..5904a6c4917 100644
--- a/src/backend/commands/discard.c
+++ b/src/backend/commands/discard.c
@@ -18,6 +18,7 @@
#include "commands/async.h"
#include "commands/discard.h"
#include "commands/prepare.h"
+#include "commands/session_variable.h"
#include "commands/sequence.h"
#include "utils/guc.h"
#include "utils/portal.h"
@@ -48,6 +49,10 @@ DiscardCommand(DiscardStmt *stmt, bool isTopLevel)
ResetTempTableNamespace();
break;
+ case DISCARD_VARIABLES:
+ ResetSessionVariables();
+ break;
+
default:
elog(ERROR, "unrecognized DISCARD target: %d", stmt->target);
}
@@ -75,4 +80,5 @@ DiscardAll(bool isTopLevel)
ResetPlanCache();
ResetTempTableNamespace();
ResetSequenceCaches();
+ ResetSessionVariables();
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index fa16f47072e..e1c86966998 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -94,7 +94,13 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
- Assert(sessionvars);
+ /*
+ * There is no guarantee of session variables being initialized, even when
+ * receiving an invalidation callback, as DISCARD [ ALL | VARIABLES ]
+ * destroys the hash table entirely.
+ */
+ if (!sessionvars)
+ return;
/*
* If the hashvalue is not specified, we have to recheck all currently
@@ -619,3 +625,23 @@ pg_session_variables(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+
+/*
+ * Fast drop of the complete content of the session variables hash table, and
+ * cleanup of any list that wouldn't be relevant anymore.
+ * This is used by the DISCARD VARIABLES (and DISCARD ALL) command.
+ */
+void
+ResetSessionVariables(void)
+{
+ /* destroy hash table and reset related memory context */
+ if (sessionvars)
+ {
+ hash_destroy(sessionvars);
+ sessionvars = NULL;
+ }
+
+ /* release memory allocated by session variables */
+ if (SVariableMemoryContext != NULL)
+ MemoryContextReset(SVariableMemoryContext);
+}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 04251bba456..2cb5c57fb61 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -2084,7 +2084,13 @@ DiscardStmt:
n->target = DISCARD_SEQUENCES;
$$ = (Node *) n;
}
+ | DISCARD VARIABLES
+ {
+ DiscardStmt *n = makeNode(DiscardStmt);
+ n->target = DISCARD_VARIABLES;
+ $$ = (Node *) n;
+ }
;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 7a508a3644f..6e4d2310f5c 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -2962,6 +2962,9 @@ CreateCommandTag(Node *parsetree)
case DISCARD_SEQUENCES:
tag = CMDTAG_DISCARD_SEQUENCES;
break;
+ case DISCARD_VARIABLES:
+ tag = CMDTAG_DISCARD_VARIABLES;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index dfe821f4b60..c0f540a4b8f 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4142,7 +4142,7 @@ match_previous_words(int pattern_id,
/* DISCARD */
else if (Matches("DISCARD"))
- COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP");
+ COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP", "VARIABLES");
/* DO */
else if (Matches("DO"))
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index 2391b9ad443..a8ca43c87af 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -27,4 +27,6 @@ extern Datum GetSessionVariable(Oid varid, bool *isNull);
extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
QueryEnvironment *queryEnv, QueryCompletion *qc);
+extern void ResetSessionVariables(void);
+
#endif
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 40f04098104..04c6126f22b 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -4047,6 +4047,7 @@ typedef enum DiscardMode
DISCARD_PLANS,
DISCARD_SEQUENCES,
DISCARD_TEMP,
+ DISCARD_VARIABLES,
} DiscardMode;
typedef struct DiscardStmt
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index 22082c30008..bef0ac25331 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -135,6 +135,7 @@ PG_CMDTAG(CMDTAG_DISCARD_ALL, "DISCARD ALL", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_PLANS, "DISCARD PLANS", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_SEQUENCES, "DISCARD SEQUENCES", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_TEMP, "DISCARD TEMP", false, false, false)
+PG_CMDTAG(CMDTAG_DISCARD_VARIABLES, "DISCARD VARIABLES", false, false, false)
PG_CMDTAG(CMDTAG_DO, "DO", false, false, false)
PG_CMDTAG(CMDTAG_DROP_ACCESS_METHOD, "DROP ACCESS METHOD", true, false, false)
PG_CMDTAG(CMDTAG_DROP_AGGREGATE, "DROP AGGREGATE", true, false, false)
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index f22467186e3..79ac40768f8 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1663,3 +1663,66 @@ DROP VARIABLE :"DBNAME".:"DBNAME".b;
DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+ var1
+-------
+ Hello
+(1 row)
+
+DISCARD ALL;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT var1;
+ var1
+------
+ AHOJ
+(1 row)
+
+DISCARD VARIABLES;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+DROP VARIABLE var1;
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS varchar;
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DISCARD VARIABLES;
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index e72360d5254..2954759aaed 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1178,3 +1178,39 @@ DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+
+DISCARD ALL;
+SELECT var1;
+
+LET var1 = 'AHOJ';
+SELECT var1;
+
+DISCARD VARIABLES;
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+
+SELECT count(*) FROM pg_session_variables();
+
+CREATE VARIABLE var1 AS varchar;
+
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+
+LET var1 = 'AHOJ';
+
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+
+DISCARD VARIABLES;
+
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
--
2.48.1
[text/x-patch] v20250301-0005-memory-cleaning-after-DROP-VARIABLE.patch (20.9K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/6-v20250301-0005-memory-cleaning-after-DROP-VARIABLE.patch)
download | inline diff:
From a4ecd797b2b2a1acc39dfc3bc4c9077439802fa0 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 09:31:28 +0100
Subject: [PATCH 05/21] memory cleaning after DROP VARIABLE
Accepting a sinval message invalidates entries in the "sessionvars" hash table.
These entries are validated before any read or write operations on session variables.
When the entry cannot be validated, it is removed. Removal will be delayed when
the variable was dropped by the current transaction, which could still be rolled back.
---
src/backend/catalog/pg_variable.c | 7 +-
src/backend/commands/session_variable.c | 153 +++++++++++-
src/include/commands/session_variable.h | 2 +
.../isolation/expected/session-variable.out | 110 +++++++++
src/test/isolation/isolation_schedule | 1 +
.../isolation/specs/session-variable.spec | 50 ++++
.../regress/expected/session_variables.out | 217 ++++++++++++++++++
src/test/regress/sql/session_variables.sql | 120 ++++++++++
8 files changed, 655 insertions(+), 5 deletions(-)
create mode 100644 src/test/isolation/expected/session-variable.out
create mode 100644 src/test/isolation/specs/session-variable.spec
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index bb445e9434b..d672d2a9cb3 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -22,6 +22,7 @@
#include "catalog/pg_collation.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
@@ -230,7 +231,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
}
/*
- * Drop variable by OID
+ * Drop variable by OID, and register the needed session variable
+ * cleanup.
*/
void
DropVariableById(Oid varid)
@@ -250,4 +252,7 @@ DropVariableById(Oid varid)
ReleaseSysCache(tup);
table_close(rel, RowExclusiveLock);
+
+ /* do the necessary cleanup in local memory, if needed */
+ SessionVariableDropPostprocess(varid);
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index e1c86966998..1596d94fb03 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -14,6 +14,7 @@
*/
#include "postgres.h"
+#include "access/xact.h"
#include "catalog/pg_variable.h"
#include "commands/session_variable.h"
#include "executor/svariableReceiver.h"
@@ -67,6 +68,14 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ /*
+ * Top level local transaction id of the last transaction that dropped the
+ * variable, if any. We need this information to avoid freeing memory for
+ * variables dropped by the local backend, in case the operation is rolled
+ * back.
+ */
+ LocalTransactionId drop_lxid;
+
/*
* Stored value and type description can be outdated when we receive a
* sinval message. We then have to check if the stored data are still
@@ -83,6 +92,17 @@ static HTAB *sessionvars = NULL; /* hash table for session variables */
static MemoryContext SVariableMemoryContext = NULL;
+/* becomes true when we receive a sinval message */
+static bool needs_validation = false;
+
+/*
+ * The content of dropped session variables is not removed immediately. We do
+ * that in the next transaction that reads or writes a session variable.
+ * "validated_lxid" stores the transaction that performed said validation, so
+ * that we can avoid repeating the effort.
+ */
+static LocalTransactionId validated_lxid = InvalidLocalTransactionId;
+
/*
* Callback function for session variable invalidation.
*/
@@ -114,6 +134,38 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
if (hashvalue == 0 || svar->hashvalue == hashvalue)
{
svar->is_valid = false;
+ needs_validation = true;
+ }
+ }
+}
+
+/*
+ * Handle the local memory cleanup for a DROP VARIABLE command.
+ *
+ * Caller should take care of removing the pg_variable entry first.
+ */
+void
+SessionVariableDropPostprocess(Oid varid)
+{
+ Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid));
+
+ if (sessionvars)
+ {
+ bool found;
+ SVariable svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_FIND, &found);
+
+ if (found)
+ {
+ /*
+ * Save the current top level local transaction id to make sure we
+ * won't automatically remove the local variable storage in
+ * validate_all_session_variables() when the invalidation message
+ * from DROP VARIABLE arrives. After all, the transaction could
+ * still be rolled back.
+ */
+ svar->is_valid = false;
+ svar->drop_lxid = MyProc->vxid.lxid;
}
}
}
@@ -167,6 +219,67 @@ is_session_variable_valid(SVariable svar)
return result;
}
+/*
+ * Check all potentially invalid session variable data in local memory and free
+ * the memory for all invalid ones. This function is called before any read or
+ * write of a session variable. Freeing of a variable's memory is postponed if
+ * the variable has been dropped by the current transaction, since that
+ * operation could still be rolled back.
+ *
+ * It is possible that we receive a cache invalidation message while
+ * remove_invalid_session_variables() is executing, so we cannot guarantee that
+ * all entries in "sessionvars" will be set to "is_valid" after the function is
+ * done. However, we can guarantee that all entries get checked once.
+ */
+static void
+remove_invalid_session_variables(void)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ /*
+ * The validation requires system catalog access, so the session state
+ * should be "in transaction".
+ */
+ Assert(IsTransactionState());
+
+ if (!needs_validation || !sessionvars)
+ return;
+
+ /*
+ * Reset the flag before we start the validation. It can be set again
+ * by concurrently incoming sinval messages.
+ */
+ needs_validation = false;
+
+ elog(DEBUG1, "effective call of validate_all_session_variables()");
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (!svar->is_valid)
+ {
+ if (svar->drop_lxid == MyProc->vxid.lxid)
+ {
+ /* try again in the next transaction */
+ needs_validation = true;
+ continue;
+ }
+
+ if (!is_session_variable_valid(svar))
+ {
+ Oid varid = svar->varid;
+
+ free_session_variable_value(svar);
+ hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ else
+ svar->is_valid = true;
+ }
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
@@ -196,6 +309,8 @@ setup_session_variable(SVariable svar, Oid varid)
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+ svar->drop_lxid = InvalidTransactionId;
+
svar->isnull = true;
svar->value = (Datum) 0;
@@ -319,22 +434,42 @@ get_session_variable(Oid varid)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
if (found)
{
+ /*
+ * The session variable could have been dropped by a DROP VARIABLE
+ * statement in a subtransaction that was later rolled back, which
+ * means that we may have to work with the data of a variable marked
+ * as invalid.
+ */
if (!svar->is_valid)
{
/*
- * If there was an invalidation message, the variable might still be
- * valid, but we have to check with the system catalog.
+ * We have to check the system catalog to see if the variable is
+ * still valid, even if an invalidation message set it to invalid.
+ *
+ * The variable must be validated before it is accessed. The oid
+ * should be valid, because the related session variable is already
+ * locked, and remove_invalid_session_variables() would remove
+ * variables dropped by other transactions.
*/
if (is_session_variable_valid(svar))
svar->is_valid = true;
else
- /* if the value cannot be validated, we have to discard it */
- free_session_variable_value(svar);
+ elog(ERROR, "unexpected state of session variable %u", varid);
}
}
else
@@ -395,6 +530,16 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index a8ca43c87af..d3cc79b5608 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -21,6 +21,8 @@
#include "tcop/cmdtag.h"
#include "utils/queryenvironment.h"
+extern void SessionVariableDropPostprocess(Oid varid);
+
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
new file mode 100644
index 00000000000..0a5579dc7ce
--- /dev/null
+++ b/src/test/isolation/expected/session-variable.out
@@ -0,0 +1,110 @@
+Parsed test spec with 4 sessions
+
+starting permutation: let val drop val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+
+starting permutation: let val s1 drop val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+step sr1: ROLLBACK;
+
+starting permutation: let val dbg drop create dbg val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name|removed
+------+----+-------
+ | |t
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+
+starting permutation: let val s1 dbg drop create dbg val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+step sr1: ROLLBACK;
+
+starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+step create3: CREATE VARIABLE myvar3 AS text;
+step let3: LET myvar3 = 'test';
+step s3: BEGIN;
+step create4: CREATE VARIABLE myvar4 AS text;
+step let4: LET myvar4 = 'test';
+step drop4: DROP VARIABLE myvar4;
+step drop3: DROP VARIABLE myvar3;
+step inval3: SELECT COUNT(*) >= 0 FROM pg_foreign_table;
+?column?
+--------
+t
+(1 row)
+
+step discard: DISCARD VARIABLES;
+step sc3: COMMIT;
+step state: SELECT varname FROM pg_variable;
+varname
+-------
+myvar
+(1 row)
+
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 143109aa4da..7453685d046 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -115,3 +115,4 @@ test: serializable-parallel-2
test: serializable-parallel-3
test: matview-write-skew
test: lock-nowait
+test: session-variable
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
new file mode 100644
index 00000000000..c864fee4006
--- /dev/null
+++ b/src/test/isolation/specs/session-variable.spec
@@ -0,0 +1,50 @@
+# Test session variables memory cleanup for sinval
+
+setup
+{
+ CREATE VARIABLE myvar AS text;
+}
+
+teardown
+{
+ DROP VARIABLE IF EXISTS myvar;
+}
+
+session s1
+step s1 { BEGIN; }
+step let { LET myvar = 'test'; }
+step val { SELECT myvar; }
+step dbg { SELECT schema, name, removed FROM pg_session_variables(); }
+step sr1 { ROLLBACK; }
+
+session s2
+step drop { DROP VARIABLE myvar; }
+step create { CREATE VARIABLE myvar AS text; }
+
+session s3
+step s3 { BEGIN; }
+step let3 { LET myvar3 = 'test'; }
+step create4 { CREATE VARIABLE myvar4 AS text; }
+step let4 { LET myvar4 = 'test'; }
+step drop4 { DROP VARIABLE myvar4; }
+step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; }
+step discard { DISCARD VARIABLES; }
+step sc3 { COMMIT; }
+step state { SELECT varname FROM pg_variable; }
+
+session s4
+step create3 { CREATE VARIABLE myvar3 AS text; }
+step drop3 { DROP VARIABLE myvar3; }
+
+# Concurrent drop of a known variable should lead to an error
+permutation let val drop val
+# Same, but with an explicit transaction
+permutation let val s1 drop val sr1
+# Concurrent drop/create of a known variable should lead to empty variable
+permutation let val dbg drop create dbg val
+# Concurrent drop/create of a known variable should lead to empty variable
+# We need a transaction to make sure that we won't accept invalidation when
+# calling the dbg step after the concurrent drop
+permutation let val s1 dbg drop create dbg val sr1
+# test for DISCARD ALL when all internal queues have actions registered
+permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 79ac40768f8..2783caa8446 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1726,3 +1726,220 @@ SELECT count(*) FROM pg_session_variables();
0
(1 row)
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+-- should fail
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1, var2;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 2954759aaed..a624ab8b67f 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1214,3 +1214,123 @@ DISCARD VARIABLES;
-- should be zero again
SELECT count(*) FROM pg_session_variables();
+
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+
+-- should fail
+SELECT var1;
+
+ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ROLLBACK;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+DROP VARIABLE var1, var2;
--
2.48.1
[text/x-patch] v20250301-0002-Storage-for-session-variables-and-SQL-interface.patch (159.6K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/7-v20250301-0002-Storage-for-session-variables-and-SQL-interface.patch)
download | inline diff:
From 34334228a6c66c8a3d6b6b1e2b19259bdd992af5 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Thu, 6 Jul 2023 08:29:21 +0200
Subject: [PATCH 02/21] Storage for session variables and SQL interface
Session variables are stored in session memory in a dedicated hash table.
They are set by the LET command and read by the SELECT command.
The access rights should be checked.
The identifiers of session variables should always be shadowed by possible
column identifiers: we don't want to break an application by creating some
badly named session variable.
The limits of this patch (solved by other patches):
- session variables block parallel execution
- session variables blocks simple expression evaluation (in plpgsql)
- SQL functions with session variables are not inlined
- CALL statement is not supported (usage of direct access to express executor)
- EXECUTE statement is not supported (usage of direct access to express executor)
- memory used by dropped session variables is not released
Implementations of EXPLAIN LET and PREPARE LET statements
are in separate patches (for better readability)
---
doc/src/sgml/catalogs.sgml | 13 +
doc/src/sgml/ddl.sgml | 61 +
doc/src/sgml/func.sgml | 4 +-
doc/src/sgml/glossary.sgml | 5 +-
doc/src/sgml/parallel.sgml | 6 +
doc/src/sgml/plpgsql.sgml | 14 +
doc/src/sgml/ref/allfiles.sgml | 1 +
doc/src/sgml/ref/alter_variable.sgml | 1 +
doc/src/sgml/ref/create_variable.sgml | 5 +-
doc/src/sgml/ref/drop_variable.sgml | 1 +
doc/src/sgml/ref/let.sgml | 96 ++
doc/src/sgml/reference.sgml | 1 +
src/backend/catalog/dependency.c | 5 +
src/backend/catalog/namespace.c | 289 ++++
src/backend/catalog/pg_variable.c | 2 +
src/backend/commands/Makefile | 1 +
src/backend/commands/meson.build | 1 +
src/backend/commands/prepare.c | 10 +
src/backend/commands/session_variable.c | 529 +++++++
src/backend/executor/Makefile | 1 +
src/backend/executor/execExpr.c | 32 +
src/backend/executor/execMain.c | 66 +
src/backend/executor/meson.build | 1 +
src/backend/executor/svariableReceiver.c | 172 +++
src/backend/nodes/nodeFuncs.c | 10 +
src/backend/optimizer/plan/planner.c | 36 +
src/backend/optimizer/plan/setrefs.c | 156 ++-
src/backend/optimizer/prep/prepjointree.c | 3 +
src/backend/optimizer/util/clauses.c | 33 +-
src/backend/parser/analyze.c | 272 +++-
src/backend/parser/gram.y | 39 +-
src/backend/parser/parse_agg.c | 9 +
src/backend/parser/parse_expr.c | 223 ++-
src/backend/parser/parse_func.c | 2 +
src/backend/parser/parse_merge.c | 1 +
src/backend/tcop/dest.c | 7 +
src/backend/tcop/utility.c | 16 +
src/backend/utils/adt/ruleutils.c | 46 +
src/backend/utils/cache/plancache.c | 41 +-
src/backend/utils/fmgr/fmgr.c | 10 +-
src/bin/psql/tab-complete.in.c | 12 +-
src/include/catalog/namespace.h | 1 +
src/include/catalog/pg_variable.h | 9 +
src/include/commands/session_variable.h | 30 +
src/include/executor/svariableReceiver.h | 22 +
src/include/nodes/execnodes.h | 14 +
src/include/nodes/parsenodes.h | 17 +
src/include/nodes/pathnodes.h | 14 +
src/include/nodes/plannodes.h | 9 +
src/include/nodes/primnodes.h | 14 +
src/include/optimizer/planmain.h | 2 +
src/include/parser/kwlist.h | 1 +
src/include/parser/parse_node.h | 3 +
src/include/tcop/cmdtaglist.h | 1 +
src/include/tcop/dest.h | 1 +
src/pl/plpgsql/src/pl_exec.c | 3 +-
.../regress/expected/session_variables.out | 1232 +++++++++++++++++
src/test/regress/sql/session_variables.sql | 883 ++++++++++++
src/tools/pgindent/typedefs.list | 5 +
59 files changed, 4467 insertions(+), 27 deletions(-)
create mode 100644 doc/src/sgml/ref/let.sgml
create mode 100644 src/backend/commands/session_variable.c
create mode 100644 src/backend/executor/svariableReceiver.c
create mode 100644 src/include/commands/session_variable.h
create mode 100644 src/include/executor/svariableReceiver.h
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 7ba91b1f4b1..4f502274bfa 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9810,6 +9810,19 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcreate_lsn</structfield> <type>pg_lsn</type>
+ </para>
+ <para>
+ LSN of the transaction where the variable was created.
+ <structfield>varcreate_lsn</structfield> and
+ <structfield>oid</structfield> together form the all-time unique
+ identifier (<structfield>oid</structfield> alone is not enough, since
+ object identifiers can get reused).
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>varname</structfield> <type>name</type>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index edfb7db24fc..5e671d5be4d 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5384,6 +5384,67 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
The session variable holds value in session memory. This value is private
to each session and is released when the session ends.
</para>
+
+ <para>
+ The value of a session variable is set with the SQL statement
+ <command>LET</command>. The value of a session variable can be retrieved
+ with the SQL statement <command>SELECT</command>.
+<programlisting>
+CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
+</programlisting>
+
+ or
+
+<programlisting>
+CREATE VARIABLE public.current_user_id AS integer;
+GRANT SELECT ON VARIABLE public.current_user_id TO PUBLIC;
+LET current_user_id = (SELECT id FROM users WHERE usename = session_user);
+SELECT current_user_id;
+</programlisting>
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a variable's value returns a <literal>NULL</literal>, unless its value has
+ been set to something else in the current session using the
+ <command>LET</command> command. Session variables are not transactional:
+ any changes made to the value of a session variable in a transaction won't
+ be undone if the transaction is rolled back (just like variables in
+ procedural languages). Session variables themselves are persistent, but
+ their values are neither persistent nor shared (like the content of
+ temporary tables).
+ </para>
+
+ <para>
+ Inside a query or an expression, a session variable can be
+ <quote>shadowed</quote> by a column with the same name. Similarly, the
+ name of a function or procedure argument or a PL/pgSQL variable (see
+ <xref linkend="plpgsql-declarations"/>) can shadow a session variable
+ in the routine's body. Such collisions of identifiers can be resolved
+ by using qualified identifiers: Session variables can be qualified with
+ the schema name, columns can use table aliases, routine variables can use
+ block labels, and routine arguments can use the routine name.
+<programlisting>
+CREATE VARIABLE name AS text;
+LET name = 'John';
+
+CREATE TABLE foo(name text);
+INSERT INTO foo VALUES('Alice');
+
+-- variable name is shadowed
+SELECT name FROM foo;
+</programlisting>
+
+ which returns:
+
+<programlisting>
+ name
+-------
+ Alice
+</programlisting>
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 1663b5339ba..3b4d5b93a4a 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25600,8 +25600,8 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
't' for <literal>TABLESPACE</literal>,
'F' for <literal>FOREIGN DATA WRAPPER</literal>,
'S' for <literal>FOREIGN SERVER</literal>,
- or
- 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal>.
+ 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal> or
+ 'V' for <literal>SESSION VARIABLE</literal>.
</para></entry>
</row>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index b921f5a3339..81988f2dfea 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1675,8 +1675,9 @@
<para>
A persistent database object that holds a value in session memory. This
value is private to each session and is released when the session ends.
- Read or write access to session variables is controlled by privileges,
- similar to other database objects.
+ The default value of the session variable is null. Read or write access
+ to session variables is controlled by privileges, similar to other database
+ objects.
</para>
<para>
For more information, see <xref linkend="ddl-session-variables"/>.
diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index 1ce9abf86f5..683dede6adc 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -515,6 +515,12 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
Plan nodes that reference a correlated <literal>SubPlan</literal>.
</para>
</listitem>
+
+ <listitem>
+ <para>
+ Plan nodes that use a session variable.
+ </para>
+ </listitem>
</itemizedlist>
<sect2 id="parallel-labeling">
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index 78e4983139b..bfbff9ab74e 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -6034,6 +6034,20 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE;
</programlisting>
</para>
</sect3>
+
+ <sect3 id="plpgsql-porting-package-variables">
+ <title><command>Packages and package variables</command></title>
+
+ <para>
+ The <application>PL/pgSQL</application> language has no packages, and
+ therefore no package variables or package constants.
+ You can consider translating an Oracle package into a schema in
+ <productname>PostgreSQL</productname>. Package functions and procedures
+ would then become functions and procedures in that schema, and package
+ variables could be translated to session variables in that schema.
+ (see <xref linkend="ddl-session-variables"/>).
+ </para>
+ </sect3>
</sect2>
<sect2 id="plpgsql-porting-appendix">
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index 2f67de3e21b..cc3bd5ab540 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -158,6 +158,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY grant SYSTEM "grant.sgml">
<!ENTITY importForeignSchema SYSTEM "import_foreign_schema.sgml">
<!ENTITY insert SYSTEM "insert.sgml">
+<!ENTITY let SYSTEM "let.sgml">
<!ENTITY listen SYSTEM "listen.sgml">
<!ENTITY load SYSTEM "load.sgml">
<!ENTITY lock SYSTEM "lock.sgml">
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
index 96d2586423e..221a699469b 100644
--- a/doc/src/sgml/ref/alter_variable.sgml
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -173,6 +173,7 @@ ALTER VARIABLE boo SET SCHEMA private;
<simplelist type="inline">
<member><xref linkend="sql-createvariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
</refentry>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index 6e988f2e472..cd9ff63975a 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -120,9 +120,11 @@ CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceab
<title>Examples</title>
<para>
- Create an date session variable <literal>var1</literal>:
+ Create a session variable <literal>var1</literal> of data type date:
<programlisting>
CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
</programlisting>
</para>
@@ -143,6 +145,7 @@ CREATE VARIABLE var1 AS date;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
index 5bdb3560f0b..67988b5fcd8 100644
--- a/doc/src/sgml/ref/drop_variable.sgml
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -111,6 +111,7 @@ DROP VARIABLE var1;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/let.sgml b/doc/src/sgml/ref/let.sgml
new file mode 100644
index 00000000000..00f9bea91fe
--- /dev/null
+++ b/doc/src/sgml/ref/let.sgml
@@ -0,0 +1,96 @@
+<!--
+doc/src/sgml/ref/let.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-let">
+ <indexterm zone="sql-let">
+ <primary>LET</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>changing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>LET</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>LET</refname>
+ <refpurpose>change a session variable's value</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+LET <replaceable class="parameter">session_variable</replaceable> = <replaceable class="parameter">sql_expression</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>LET</command> command assigns a value to the specified session
+ variable.
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">session_variable</replaceable></term>
+ <listitem>
+ <para>
+ The name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">sql_expression</replaceable></term>
+ <listitem>
+ <para>
+ An arbitrary SQL expression. The result must be of a data type that can
+ be cast to the type of the session variable in an assignment.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+<programlisting>
+CREATE VARIABLE myvar AS integer;
+LET myvar = 10;
+LET myvar = (SELECT sum(val) FROM tab);
+</programlisting>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>LET</command> is a <productname>PostgreSQL</productname>
+ extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index 25578f3946c..13e4adc5df3 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -186,6 +186,7 @@
&grant;
&importForeignSchema;
&insert;
+ &let;
&listen;
&load;
&lock;
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 9e0f648b74f..90c9e8bb254 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1864,6 +1864,11 @@ find_expr_references_walker(Node *node,
{
Param *param = (Param *) node;
+ /* a variable parameter depends on the session variable */
+ if (param->paramkind == PARAM_VARIABLE)
+ add_object_address(VariableRelationId, param->paramvarid, 0,
+ context->addrs);
+
/* A parameter must depend on the parameter's datatype */
add_object_address(TypeRelationId, param->paramtype, 0,
context->addrs);
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 4307cad15c7..beafee2a341 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -3497,6 +3497,295 @@ NamesFromList(List *names)
return result;
}
+/* -----
+ * IdentifyVariable - try to find a variable from a list of identifiers
+ *
+ * Returns the OID of the variable found, or InvalidOid.
+ *
+ * "names" is a list of up to four identifiers; possible meanings are:
+ * - variable (searched on the search_path)
+ * - schema.variable
+ * - variable.attribute (searched on the search_path)
+ * - schema.variable.attribute
+ * - database.schema.variable
+ * - database.schema.variable.attribute
+ *
+ * If there is more than one way to identify a variable, "not_unique" will be
+ * set to true.
+ *
+ * Unless "noerror" is true, an error is raised if there are more than four
+ * identifiers in the list, or if the named database is not the current one.
+ * This is useful if we want to identify a shadowed variable.
+ *
+ * If an attribute is identified, it is stored in "attrname", otherwise the
+ * parameter is set to NULL.
+ *
+ * The identified session variable will be locked with an AccessShareLock.
+ * -----
+ */
+Oid
+IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror)
+{
+ Oid varid = InvalidOid;
+ Oid old_varid = InvalidOid;
+ uint64 inval_count;
+ bool retry = false;
+
+ /*
+ * DDL operations can change the results of a name lookup. Since all such
+ * operations will generate invalidation messages, we keep track of
+ * whether any such messages show up while we're performing the operation,
+ * and retry until either (1) no more invalidation messages show up or (2)
+ * the answer doesn't change.
+ */
+ for (;;)
+ {
+ Node *field1 = NULL;
+ Node *field2 = NULL;
+ Node *field3 = NULL;
+ Node *field4 = NULL;
+ char *a = NULL;
+ char *b = NULL;
+ char *c = NULL;
+ char *d = NULL;
+ Oid varoid_without_attr = InvalidOid;
+ Oid varoid_with_attr = InvalidOid;
+
+ *not_unique = false;
+ *attrname = NULL;
+ varid = InvalidOid;
+
+ inval_count = SharedInvalidMessageCounter;
+
+ switch (list_length(names))
+ {
+ case 1:
+ field1 = linitial(names);
+
+ Assert(IsA(field1, String));
+
+ varid = LookupVariable(NULL, strVal(field1), true);
+ break;
+
+ case 2:
+ field1 = linitial(names);
+ field2 = lsecond(names);
+
+ Assert(IsA(field1, String));
+ a = strVal(field1);
+
+ if (IsA(field2, String))
+ {
+ /* when both fields are of string type */
+ b = strVal(field2);
+
+ /*
+ * a.b can mean "schema"."variable" or
+ * "variable"."attribute". Check both variants, and
+ * returns InvalidOid with not_unique flag, when both
+ * interpretations are possible.
+ */
+ varoid_without_attr = LookupVariable(a, b, true);
+ varoid_with_attr = LookupVariable(NULL, a, true);
+ }
+ else
+ {
+ /* the last field of list can be star too */
+ Assert(IsA(field2, A_Star));
+
+ /*
+ * The syntax ident.* is used only by relation aliases,
+ * and then this identifier cannot be a reference to
+ * session variable.
+ */
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = b;
+ varid = varoid_with_attr;
+ }
+ break;
+
+ case 3:
+ {
+ bool field1_is_catalog = false;
+
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+
+ if (IsA(field3, String))
+ {
+ c = strVal(field3);
+
+ /*
+ * a.b.c can mean catalog.schema.variable or
+ * schema.variable.attribute.
+ *
+ * Check both variants, and set not_unique flag, when
+ * both interpretations are possible.
+ *
+ * When third node is star, only possible
+ * interpretation is schema.variable.*, but this
+ * pattern is not supported now.
+ */
+ varoid_with_attr = LookupVariable(a, b, true);
+
+ /*
+ * check pattern catalog.schema.variable only when
+ * there is possibility to success.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) == 0)
+ {
+ field1_is_catalog = true;
+ varoid_without_attr = LookupVariable(b, c, true);
+ }
+ }
+ else
+ {
+ Assert(IsA(field3, A_Star));
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = c;
+ varid = varoid_with_attr;
+ }
+
+ /*
+ * When we didn't find variable, we can (when it is
+ * allowed) raise cross-database reference error.
+ */
+ if (!OidIsValid(varid) && !noerror && !field1_is_catalog)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+ break;
+
+ case 4:
+ {
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+ field4 = lfourth(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+ Assert(IsA(field3, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+ c = strVal(field3);
+
+ /*
+ * In this case, "a" is used as catalog name - check it.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) != 0)
+ {
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+
+ if (IsA(field4, String))
+ {
+ d = strVal(field4);
+ }
+ else
+ {
+ Assert(IsA(field4, A_Star));
+ return InvalidOid;
+ }
+
+ *attrname = d;
+ varid = LookupVariable(b, c, true);
+ }
+ break;
+
+ default:
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper qualified name (too many dotted names): %s",
+ NameListToString(names))));
+ return InvalidOid;
+ }
+
+ /*
+ * If, upon retry, we get back the same OID we did last time, then the
+ * invalidation messages we processed did not change the final answer.
+ * So we're done.
+ *
+ * If we got a different OID, we've locked the variable that used to
+ * have this name rather than the one that does now. So release the
+ * lock.
+ */
+ if (retry)
+ {
+ if (old_varid == varid)
+ break;
+
+ if (OidIsValid(old_varid))
+ UnlockDatabaseObject(VariableRelationId, old_varid, 0, AccessShareLock);
+ }
+
+ /*
+ * Lock the variable. This will also accept any pending invalidation
+ * messages. If we got back InvalidOid, indicating not found, then
+ * there's nothing to lock, but we accept invalidation messages
+ * anyway, to flush any negative catcache entries that may be
+ * lingering.
+ */
+ if (!OidIsValid(varid))
+ AcceptInvalidationMessages();
+ else
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ /*
+ * If no invalidation message were processed, we're done!
+ */
+ if (inval_count == SharedInvalidMessageCounter)
+ break;
+
+ retry = true;
+ old_varid = varid;
+ varid = InvalidOid;
+ }
+
+ return varid;
+}
+
/*
* DeconstructQualifiedName
* Given a possibly-qualified name expressed as a list of String nodes,
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 29d967a2d5b..bb445e9434b 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -26,6 +26,7 @@
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
+#include "utils/pg_lsn.h"
#include "utils/syscache.h"
static ObjectAddress create_variable(const char *varName,
@@ -101,6 +102,7 @@ create_variable(const char *varName,
varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varcreate_lsn - 1] = LSNGetDatum(GetXLogInsertRecPtr());
values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile
index 85cfea6fd71..55de062c205 100644
--- a/src/backend/commands/Makefile
+++ b/src/backend/commands/Makefile
@@ -52,6 +52,7 @@ OBJS = \
schemacmds.o \
seclabel.o \
sequence.o \
+ session_variable.o \
statscmds.o \
subscriptioncmds.o \
tablecmds.o \
diff --git a/src/backend/commands/meson.build b/src/backend/commands/meson.build
index ce8d1ab8bac..ba2891e037b 100644
--- a/src/backend/commands/meson.build
+++ b/src/backend/commands/meson.build
@@ -40,6 +40,7 @@ backend_sources += files(
'schemacmds.c',
'seclabel.c',
'sequence.c',
+ 'session_variable.c',
'statscmds.c',
'subscriptioncmds.c',
'tablecmds.c',
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 4d68d4d25c7..2d04c71a148 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -340,6 +340,16 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
i++;
}
+ /*
+ * The arguments of EXECUTE are evaluated by a direct expression
+ * executor call. This mode doesn't support session variables yet.
+ * It will be enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
/* Prepare the expressions for execution */
exprstates = ExecPrepareExprList(params, estate);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
new file mode 100644
index 00000000000..d2891a1dcb7
--- /dev/null
+++ b/src/backend/commands/session_variable.c
@@ -0,0 +1,529 @@
+/*-------------------------------------------------------------------------
+ *
+ * session_variable.c
+ * session variable creation/manipulation commands
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/commands/session_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "rewrite/rewriteHandler.h"
+#include "storage/lmgr.h"
+#include "storage/proc.h"
+#include "tcop/tcopprot.h"
+#include "utils/builtins.h"
+#include "utils/datum.h"
+#include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/snapmgr.h"
+#include "utils/syscache.h"
+
+/*
+ * The values of session variables are stored in the backend's private memory
+ * in the dedicated memory context SVariableMemoryContext in binary format.
+ * They are stored in the "sessionvars" hash table, whose key is the OID of the
+ * variable. However, the OID is not good enough to identify a session
+ * variable: concurrent sessions could drop the session variable and create a
+ * new one, which could be assigned the same OID. To ensure that the values
+ * stored in memory and the catalog definition match, we also keep track of
+ * the "create_lsn". Before any access to the variable values, we need to
+ * check if the LSN stored in memory matches the LSN in the catalog. If there
+ * is a mismatch between the LSNs, or if the OID is not present in pg_variable
+ * at all, the value stored in memory is released.
+ */
+typedef struct SVariableData
+{
+ Oid varid; /* pg_variable OID of the variable (hash key) */
+ XLogRecPtr create_lsn;
+
+ bool isnull;
+ Datum value;
+
+ Oid typid;
+ int16 typlen;
+ bool typbyval;
+
+ bool is_domain;
+
+ /*
+ * domain_check_extra holds cached domain metadata. This "extra" is
+ * usually stored in fn_mcxt. We do not have access to that memory context
+ * for session variables, but we can use TopTransactionContext instead.
+ * A fresh value is forced when we detect we are in a different transaction
+ * (the local transaction ID differs from domain_check_extra_lxid).
+ */
+ void *domain_check_extra;
+ LocalTransactionId domain_check_extra_lxid;
+
+ /*
+ * Stored value and type description can be outdated when we receive a
+ * sinval message. We then have to check if the stored data are still
+ * trustworthy.
+ */
+ bool is_valid;
+
+ uint32 hashvalue; /* used for pairing sinval message */
+} SVariableData;
+
+typedef SVariableData *SVariable;
+
+static HTAB *sessionvars = NULL; /* hash table for session variables */
+
+static MemoryContext SVariableMemoryContext = NULL;
+
+/*
+ * Callback function for session variable invalidation.
+ */
+static void
+pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
+
+ Assert(sessionvars);
+
+ /*
+ * If the hashvalue is not specified, we have to recheck all currently
+ * used session variables. Since we can't tell the exact session variable
+ * from its hashvalue, we have to iterate over all items in the hash bucket.
+ */
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (hashvalue == 0 || svar->hashvalue == hashvalue)
+ {
+ svar->is_valid = false;
+ }
+ }
+}
+
+/*
+ * Release stored value, free memory
+ */
+static void
+free_session_variable_value(SVariable svar)
+{
+ /* clean the current value */
+ if (!svar->isnull)
+ {
+ if (!svar->typbyval)
+ pfree(DatumGetPointer(svar->value));
+
+ svar->isnull = true;
+ }
+
+ svar->value = (Datum) 0;
+}
+
+/*
+ * Returns true when the entry in pg_variable is consistent with the given
+ * session variable.
+ */
+static bool
+is_session_variable_valid(SVariable svar)
+{
+ HeapTuple tp;
+ bool result = false;
+
+ Assert(OidIsValid(svar->varid));
+
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ /*
+ * The OID alone is not enough as an unique identifier, because OID
+ * values get recycled, and a new session variable could have got
+ * the same OID. We do a second check against the 64-bit LSN when
+ * the variable was created.
+ */
+ if (svar->create_lsn == ((Form_pg_variable) GETSTRUCT(tp))->varcreate_lsn)
+ result = true;
+
+ ReleaseSysCache(tp);
+ }
+
+ return result;
+}
+
+/*
+ * Initialize attributes cached in "svar"
+ */
+static void
+setup_session_variable(SVariable svar, Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ Assert(OidIsValid(varid));
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ svar->varid = varid;
+ svar->create_lsn = varform->varcreate_lsn;
+
+ svar->typid = varform->vartype;
+
+ get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval);
+
+ svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
+ svar->domain_check_extra = NULL;
+ svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+
+ svar->isnull = true;
+ svar->value = (Datum) 0;
+
+ svar->is_valid = true;
+
+ svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ ReleaseSysCache(tup);
+}
+
+/*
+ * Assign a new value to the session variable. It is copied to
+ * SVariableMemoryContext if necessary.
+ *
+ * If any error happens, the existing value won't be modified.
+ */
+static void
+set_session_variable(SVariable svar, Datum value, bool isnull)
+{
+ Datum newval;
+ SVariableData locsvar,
+ *_svar;
+
+ Assert(svar);
+ Assert(!isnull || value == (Datum) 0);
+
+ /*
+ * Use typbyval, typbylen from session variable only when they are
+ * trustworthy (the invalidation message was not accepted for this
+ * variable). If the variable might be invalid, force setup.
+ *
+ * Do not overwrite the passed session variable until we can be certain
+ * that no error can be thrown.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(&locsvar, svar->varid);
+ _svar = &locsvar;
+ }
+ else
+ _svar = svar;
+
+ if (!isnull)
+ {
+ MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
+
+ newval = datumCopy(value, _svar->typbyval, _svar->typlen);
+
+ MemoryContextSwitchTo(oldcxt);
+ }
+ else
+ newval = value;
+
+ free_session_variable_value(svar);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ svar->varid);
+
+ /* no more error expected, so we can overwrite the old variable now */
+ if (svar != _svar)
+ memcpy(svar, _svar, sizeof(SVariableData));
+
+ svar->value = newval;
+ svar->isnull = isnull;
+}
+
+/*
+ * Create the hash table for storing session variables.
+ */
+static void
+create_sessionvars_hashtables(void)
+{
+ HASHCTL vars_ctl;
+
+ Assert(!sessionvars);
+
+ if (!SVariableMemoryContext)
+ {
+ /* read sinval messages */
+ CacheRegisterSyscacheCallback(VARIABLEOID,
+ pg_variable_cache_callback,
+ (Datum) 0);
+
+ /* we need our own long-lived memory context */
+ SVariableMemoryContext =
+ AllocSetContextCreate(TopMemoryContext,
+ "session variables",
+ ALLOCSET_START_SMALL_SIZES);
+ }
+
+ memset(&vars_ctl, 0, sizeof(vars_ctl));
+ vars_ctl.keysize = sizeof(Oid);
+ vars_ctl.entrysize = sizeof(SVariableData);
+ vars_ctl.hcxt = SVariableMemoryContext;
+
+ sessionvars = hash_create("Session variables", 64, &vars_ctl,
+ HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+}
+
+/*
+ * Search a session variable in the hash table given its OID. If it
+ * doesn't exist, then insert it there.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the
+ * session variable until the end of the transaction.
+ */
+static SVariable
+get_session_variable(Oid varid)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect the used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (found)
+ {
+ if (!svar->is_valid)
+ {
+ /*
+ * If there was an invalidation message, the variable might still be
+ * valid, but we have to check with the system catalog.
+ */
+ if (is_session_variable_valid(svar))
+ svar->is_valid = true;
+ else
+ /* if the value cannot be validated, we have to discard it */
+ free_session_variable_value(svar);
+ }
+ }
+ else
+ svar->is_valid = false;
+
+ /*
+ * Force setup for not yet initialized variables or variables that cannot
+ * be validated.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ varid);
+ }
+
+ /* ensure the returned data is still of the correct domain */
+ if (svar->is_domain)
+ {
+ /*
+ * Store "extra" for domain_check() in TopTransactionContext. When we
+ * are in a new transaction, domain_check_extra cache is not valid any
+ * more.
+ */
+ if (svar->domain_check_extra_lxid != MyProc->vxid.lxid)
+ svar->domain_check_extra = NULL;
+
+ domain_check(svar->value, svar->isnull,
+ svar->typid, &svar->domain_check_extra,
+ TopTransactionContext);
+
+ svar->domain_check_extra_lxid = MyProc->vxid.lxid;
+ }
+
+ return svar;
+}
+
+/*
+ * Store the given value in a session variable in the cache.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the session
+ * variable until the end of the transaction.
+ */
+void
+SetSessionVariable(Oid varid, Datum value, bool isNull)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (!found)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ varid);
+ }
+
+ /* if this fails, it won't change the stored value */
+ set_session_variable(svar, value, isNull);
+}
+
+/*
+ * Returns a copy of the value stored in a variable.
+ */
+static inline Datum
+copy_session_variable_value(SVariable svar, bool *isNull)
+{
+ Datum value;
+
+ /* force copy of non NULL value */
+ if (!svar->isnull)
+ {
+ value = datumCopy(svar->value, svar->typbyval, svar->typlen);
+ *isNull = false;
+ }
+ else
+ {
+ value = (Datum) 0;
+ *isNull = true;
+ }
+
+ return value;
+}
+
+/*
+ * Returns a copy of the value of the session variable (in the current memory
+ * context). The caller is responsible for permission checks.
+ */
+Datum
+GetSessionVariable(Oid varid, bool *isNull)
+{
+ SVariable svar;
+
+ svar = get_session_variable(varid);
+
+ /*
+ * Although "svar" is freshly validated in this point, svar->is_valid can
+ * be false, if an invalidation message was processed during the domain check.
+ * But the variable and all its dependencies are locked now, so we don't need
+ * to repeat the validation.
+ */
+ return copy_session_variable_value(svar, isNull);
+}
+
+/*
+ * Assign the result of the evaluated expression to the session variable
+ */
+void
+ExecuteLetStmt(ParseState *pstate,
+ LetStmt *stmt,
+ ParamListInfo params,
+ QueryEnvironment *queryEnv,
+ QueryCompletion *qc)
+{
+ Query *query = castNode(Query, stmt->query);
+ List *rewritten;
+ DestReceiver *dest;
+ AclResult aclresult;
+ PlannedStmt *plan;
+ QueryDesc *queryDesc;
+ Oid varid = query->resultVariable;
+
+ Assert(OidIsValid(varid));
+
+ /* do we have permission to write to the session variable? */
+ aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid));
+
+ /* create a dest receiver for LET */
+ dest = CreateVariableDestReceiver(varid);
+
+ /* run the query rewriter */
+ query = copyObject(query);
+
+ rewritten = QueryRewrite(query);
+
+ Assert(list_length(rewritten) == 1);
+
+ query = linitial_node(Query, rewritten);
+ Assert(query->commandType == CMD_SELECT);
+
+ /* plan the query */
+ plan = pg_plan_query(query, pstate->p_sourcetext,
+ CURSOR_OPT_PARALLEL_OK, params);
+
+ /*
+ * Use a snapshot with an updated command ID to ensure this query sees the
+ * results of any previously executed queries. (This could only matter if
+ * the planner executed an allegedly-stable function that changed the
+ * database contents, but let's do it anyway to be parallel to the EXPLAIN
+ * code path.)
+ */
+ PushCopiedSnapshot(GetActiveSnapshot());
+ UpdateActiveSnapshotCommandId();
+
+ /* create a QueryDesc, redirecting output to our tuple receiver */
+ queryDesc = CreateQueryDesc(plan, NULL, pstate->p_sourcetext,
+ GetActiveSnapshot(), InvalidSnapshot,
+ dest, params, queryEnv, 0);
+
+ /* call ExecutorStart to prepare the plan for execution */
+ ExecutorStart(queryDesc, 0);
+
+ /*
+ * Run the plan to completion. The result should be only one row. To
+ * check if there are too many result rows, we try to fetch two.
+ */
+ ExecutorRun(queryDesc, ForwardScanDirection, 2L);
+
+ /* save the rowcount if we're given a QueryCompletion to fill */
+ if (qc)
+ SetQueryCompletion(qc, CMDTAG_LET, queryDesc->estate->es_processed);
+
+ /* and clean up */
+ ExecutorFinish(queryDesc);
+ ExecutorEnd(queryDesc);
+
+ FreeQueryDesc(queryDesc);
+
+ PopActiveSnapshot();
+}
diff --git a/src/backend/executor/Makefile b/src/backend/executor/Makefile
index 11118d0ce02..71248a34f26 100644
--- a/src/backend/executor/Makefile
+++ b/src/backend/executor/Makefile
@@ -76,6 +76,7 @@ OBJS = \
nodeWindowAgg.o \
nodeWorktablescan.o \
spi.o \
+ svariableReceiver.o \
tqueue.o \
tstoreReceiver.o
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 03566c4d181..270e6d344be 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -1041,6 +1041,38 @@ ExecInitExprRec(Expr *node, ExprState *state,
scratch.d.param.paramtype = param->paramtype;
ExprEvalPushStep(state, &scratch);
break;
+
+ case PARAM_VARIABLE:
+ {
+ int es_num_session_variables = 0;
+ SessionVariableValue *es_session_variables = NULL;
+ SessionVariableValue *var;
+
+ if (state->parent && state->parent->state)
+ {
+ es_session_variables = state->parent->state->es_session_variables;
+ es_num_session_variables = state->parent->state->es_num_session_variables;
+ }
+
+ Assert(es_session_variables);
+
+ /* parameter sanity checks */
+ if (param->paramid >= es_num_session_variables)
+ elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
+
+ var = &es_session_variables[param->paramid];
+
+ /*
+ * In this case, pass the value like a
+ * constant.
+ */
+ scratch.opcode = EEOP_CONST;
+ scratch.d.constval.value = var->value;
+ scratch.d.constval.isnull = var->isnull;
+ ExprEvalPushStep(state, &scratch);
+ }
+ break;
+
case PARAM_EXTERN:
/*
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 0493b7d5365..67e0b9ba2ac 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -43,7 +43,9 @@
#include "access/xact.h"
#include "catalog/namespace.h"
#include "catalog/partition.h"
+#include "catalog/pg_variable.h"
#include "commands/matview.h"
+#include "commands/session_variable.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/execPartition.h"
@@ -203,6 +205,70 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
Assert(queryDesc->sourceText != NULL);
estate->es_sourceText = queryDesc->sourceText;
+ /*
+ * The executor doesn't work with session variables directly. Values of
+ * related session variables are copied to a dedicated array, and this array
+ * is passed to the executor. This array is stable "snapshot" of values of
+ * used session variables. There are three benefits of this strategy:
+ *
+ * - consistency with external parameters and plpgsql variables,
+ *
+ * - session variables can be parallel safe,
+ *
+ * - we don't need make fresh copy for any read of session variable
+ * (this is necessary because the internally the session variable can
+ * be changed inside query execution time, and then a reference to
+ * previously returned value can be corrupted).
+ */
+ if (queryDesc->plannedstmt->sessionVariables)
+ {
+ int nSessionVariables;
+ int i = 0;
+
+ /*
+ * In this case, the query uses session variables, but we have to
+ * prepare the array with passed values (of used session variables)
+ * first.
+ */
+ Assert(!IsParallelWorker());
+ nSessionVariables = list_length(queryDesc->plannedstmt->sessionVariables);
+
+ /* create the array used for passing values of used session variables */
+ estate->es_session_variables = (SessionVariableValue *)
+ palloc(nSessionVariables * sizeof(SessionVariableValue));
+
+ /* fill the array */
+ foreach_oid(varid, queryDesc->plannedstmt->sessionVariables)
+ {
+ /*
+ * Permission check should be executed on all explicitly used
+ * variables in the query. For implicitly used variable
+ * (like base node of assignment indirect) we cannot do permission
+ * check, because we need read the value (and user can have
+ * only UPDATE variable). In this case the permission check
+ * is executed in write time.
+ */
+ if (varid != queryDesc->plannedstmt->exclSelectPermCheckVarid)
+ {
+ AclResult aclresult;
+
+ aclresult = object_aclcheck(VariableRelationId, varid,
+ GetUserId(), ACL_SELECT);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE,
+ get_session_variable_name(varid));
+ }
+
+ estate->es_session_variables[i].value =
+ GetSessionVariable(varid,
+ &estate->es_session_variables[i].isnull);
+
+ i++;
+ }
+
+ estate->es_num_session_variables = nSessionVariables;
+ }
+
/*
* Fill in the query environment, if any, from queryDesc.
*/
diff --git a/src/backend/executor/meson.build b/src/backend/executor/meson.build
index 2cea41f8771..491092fcc4c 100644
--- a/src/backend/executor/meson.build
+++ b/src/backend/executor/meson.build
@@ -64,6 +64,7 @@ backend_sources += files(
'nodeWindowAgg.c',
'nodeWorktablescan.c',
'spi.c',
+ 'svariableReceiver.c',
'tqueue.c',
'tstoreReceiver.c',
)
diff --git a/src/backend/executor/svariableReceiver.c b/src/backend/executor/svariableReceiver.c
new file mode 100644
index 00000000000..c6163fb36f6
--- /dev/null
+++ b/src/backend/executor/svariableReceiver.c
@@ -0,0 +1,172 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.c
+ * An implementation of DestReceiver that stores the result value in
+ * a session variable.
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/executor/svariableReceiver.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "miscadmin.h"
+
+#include "access/detoast.h"
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "storage/lock.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+/*
+ * This DestReceiver is used by the LET command for storing the result to a
+ * session variable. The result has to have only one tuple with only one
+ * non-deleted attribute. The row counter (field "rows") is incremented
+ * after receiving a row, and an error is raised when there are no rows or
+ * there are more than one received rows. A received tuple cannot to have
+ * deleted attributes. The value is detoasted before storing it in the
+ * session variable.
+ */
+typedef struct
+{
+ DestReceiver pub;
+ Oid varid;
+ bool need_detoast; /* do we need to detoast the attribute? */
+ int rows; /* row counter */
+} SVariableState;
+
+/*
+ * Prepare to receive tuples from executor.
+ */
+static void
+svariableStartupReceiver(DestReceiver *self, int operation, TupleDesc typeinfo)
+{
+ SVariableState *myState = (SVariableState *) self;
+ LOCKTAG locktag PG_USED_FOR_ASSERTS_ONLY;
+ Form_pg_attribute attr;
+ Oid typid PG_USED_FOR_ASSERTS_ONLY;
+ Oid collid PG_USED_FOR_ASSERTS_ONLY;
+ int32 typmod PG_USED_FOR_ASSERTS_ONLY;
+
+ Assert(myState->pub.mydest == DestVariable);
+ Assert(OidIsValid(myState->varid));
+ Assert(SearchSysCacheExists1(VARIABLEOID, myState->varid));
+ Assert(typeinfo->natts == 1);
+
+#ifdef USE_ASSERT_CHECKING
+
+ SET_LOCKTAG_OBJECT(locktag,
+ MyDatabaseId,
+ VariableRelationId,
+ myState->varid,
+ 0);
+
+ Assert(LockHeldByMe(&locktag, AccessShareLock, false));
+
+#endif
+
+ attr = TupleDescAttr(typeinfo, 0);
+
+ Assert(!attr->attisdropped);
+
+#ifdef USE_ASSERT_CHECKING
+
+ get_session_variable_type_typmod_collid(myState->varid,
+ &typid,
+ &typmod,
+ &collid);
+
+ Assert(attr->atttypid == typid);
+ Assert(attr->atttypmod < 0 || attr->atttypmod == typmod);
+
+#endif
+
+ myState->need_detoast = attr->attlen == -1;
+ myState->rows = 0;
+}
+
+/*
+ * Receive a tuple from the executor and store it in the session variable.
+ */
+static bool
+svariableReceiveSlot(TupleTableSlot *slot, DestReceiver *self)
+{
+ SVariableState *myState = (SVariableState *) self;
+ Datum value;
+ bool isnull;
+ bool freeval = false;
+
+ /* make sure the tuple is fully deconstructed */
+ slot_getallattrs(slot);
+
+ value = slot->tts_values[0];
+ isnull = slot->tts_isnull[0];
+
+ if (myState->need_detoast && !isnull && VARATT_IS_EXTERNAL(DatumGetPointer(value)))
+ {
+ value = PointerGetDatum(detoast_external_attr((struct varlena *)
+ DatumGetPointer(value)));
+ freeval = true;
+ }
+
+ myState->rows += 1;
+
+ if (myState->rows > 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_TOO_MANY_ROWS),
+ errmsg("expression returned more than one row")));
+
+ SetSessionVariable(myState->varid, value, isnull);
+
+ if (freeval)
+ pfree(DatumGetPointer(value));
+
+ return true;
+}
+
+/*
+ * Clean up at end of the executor run
+ */
+static void
+svariableShutdownReceiver(DestReceiver *self)
+{
+ if (((SVariableState *) self)->rows == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_NO_DATA_FOUND),
+ errmsg("expression returned no rows")));
+}
+
+/*
+ * Destroy the receiver when we are done with it
+ */
+static void
+svariableDestroyReceiver(DestReceiver *self)
+{
+ pfree(self);
+}
+
+/*
+ * Initially create a DestReceiver object.
+ */
+DestReceiver *
+CreateVariableDestReceiver(Oid varid)
+{
+ SVariableState *self = (SVariableState *) palloc0(sizeof(SVariableState));
+
+ self->pub.receiveSlot = svariableReceiveSlot;
+ self->pub.rStartup = svariableStartupReceiver;
+ self->pub.rShutdown = svariableShutdownReceiver;
+ self->pub.rDestroy = svariableDestroyReceiver;
+ self->pub.mydest = DestVariable;
+
+ self->varid = varid;
+
+ return (DestReceiver *) self;
+}
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f1..d8fc3d9fa69 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4375,6 +4375,16 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_LetStmt:
+ {
+ LetStmt *stmt = (LetStmt *) node;
+
+ if (WALK(stmt->target))
+ return true;
+ if (WALK(stmt->query))
+ return true;
+ }
+ break;
case T_PLAssignStmt:
{
PLAssignStmt *stmt = (PLAssignStmt *) node;
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 36ee6dd43de..41090462ce5 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -333,6 +333,21 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
glob->lastPlanNodeId = 0;
glob->transientPlan = false;
glob->dependsOnRole = false;
+ glob->sessionVariables = NIL;
+
+ /*
+ * The (session) result variable should be stored to global, because
+ * it is not set in subquery. When this variable is used other than
+ * in base node of assignment indirection, we need to check the access
+ * rights (and then we need to detect this situation). The variable used
+ * like base node cannot be different than target (result) variable.
+ * Because we know the result variable before planner invocation, we
+ * can simply search of usage just this variable, and we don't need to
+ * to wait until the end of planning when we know basenodeSessionVarid.
+ */
+ glob->resultVariable = parse->resultVariable;
+ glob->basenodeSessionVarid = InvalidOid;
+ glob->basenodeSessionVarSelectCheck = false;
/*
* Assess whether it's feasible to use parallel mode for this query. We
@@ -570,6 +585,20 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
result->paramExecTypes = glob->paramExecTypes;
/* utilityStmt should be null, but we might as well copy it */
result->utilityStmt = parse->utilityStmt;
+
+ result->sessionVariables = glob->sessionVariables;
+
+ /*
+ * The session variable used (and only used) like base node
+ * for assignemnt indirection should be excluded from permission
+ * check.
+ */
+ if (OidIsValid(glob->basenodeSessionVarid) &&
+ (!glob->basenodeSessionVarSelectCheck))
+ result->exclSelectPermCheckVarid = glob->basenodeSessionVarid;
+ else
+ result->exclSelectPermCheckVarid = InvalidOid;
+
result->stmt_location = parse->stmt_location;
result->stmt_len = parse->stmt_len;
@@ -748,6 +777,13 @@ subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root,
*/
pull_up_subqueries(root);
+ /*
+ * Check if some subquery uses a session variable. The flag
+ * hasSessionVariables should be true if the query or some subquery uses a
+ * session variable.
+ */
+ pull_up_has_session_variables(root);
+
/*
* If this is a simple UNION ALL query, flatten it into an appendrel. We
* do this now because it requires applying pull_up_subqueries to the leaf
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 999a5a8ab5a..dc2caa520f7 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -210,6 +210,9 @@ static List *set_returning_clause_references(PlannerInfo *root,
static List *set_windowagg_runcondition_references(PlannerInfo *root,
List *runcondition,
Plan *plan);
+static bool pull_up_has_session_variables_walker(Node *node,
+ PlannerInfo *root);
+static void record_plan_variable_dependency(PlannerInfo *root, Oid varid);
/*****************************************************************************
@@ -1315,6 +1318,50 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
return plan;
}
+/*
+ * Search usage of session variables in subqueries
+ */
+void
+pull_up_has_session_variables(PlannerInfo *root)
+{
+ Query *query = root->parse;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ }
+ else
+ {
+ (void) query_tree_walker(query,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+}
+
+static bool
+pull_up_has_session_variables_walker(Node *node, PlannerInfo *root)
+{
+ if (node == NULL)
+ return false;
+ if (IsA(node, Query))
+ {
+ Query *query = (Query *) node;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ return false;
+ }
+
+ /* recurse into subselects */
+ return query_tree_walker((Query *) node,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+ return expression_tree_walker(node, pull_up_has_session_variables_walker,
+ (void *) root);
+}
+
/*
* set_indexonlyscan_references
* Do set_plan_references processing on an IndexOnlyScan
@@ -2015,8 +2062,9 @@ copyVar(Var *var)
* This is code that is common to all variants of expression-fixing.
* We must look up operator opcode info for OpExpr and related nodes,
* add OIDs from regclass Const nodes into root->glob->relationOids, and
- * add PlanInvalItems for user-defined functions into root->glob->invalItems.
- * We also fill in column index lists for GROUPING() expressions.
+ * add PlanInvalItems for user-defined functions and session variables into
+ * root->glob->invalItems. We also fill in column index lists for GROUPING()
+ * expressions.
*
* We assume it's okay to update opcode info in-place. So this could possibly
* scribble on the planner's input data structures, but it's OK.
@@ -2106,6 +2154,13 @@ fix_expr_common(PlannerInfo *root, Node *node)
g->cols = cols;
}
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ record_plan_variable_dependency(root, p->paramvarid);
+ }
}
/*
@@ -2115,6 +2170,10 @@ fix_expr_common(PlannerInfo *root, Node *node)
* If it's a PARAM_MULTIEXPR, replace it with the appropriate Param from
* root->multiexpr_params; otherwise no change is needed.
* Just for paranoia's sake, we make a copy of the node in either case.
+ *
+ * If it's a PARAM_VARIABLE, then we collect used session variables in
+ * the list root->glob->sessionVariable. Also, assign the parameter's
+ * "paramid" to the parameter's position in that list.
*/
static Node *
fix_param_node(PlannerInfo *root, Param *p)
@@ -2133,6 +2192,62 @@ fix_param_node(PlannerInfo *root, Param *p)
elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid);
return copyObject(list_nth(params, colno - 1));
}
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ int n = 0;
+ bool found = false;
+
+ /* we will modify object */
+ p = (Param *) copyObject(p);
+
+ /*
+ * Now, we can actualize list of session variables, and we can
+ * complete paramid parameter.
+ */
+ foreach_oid(varid, root->glob->sessionVariables)
+ {
+ if (varid == p->paramvarid)
+ {
+ p->paramid = n;
+ found = true;
+ break;
+ }
+ n += 1;
+ }
+
+ if (!found)
+ {
+ root->glob->sessionVariables = lappend_oid(root->glob->sessionVariables,
+ p->paramvarid);
+ p->paramid = n;
+ }
+
+ /*
+ * We do SELECT permission check of all variables used by
+ * the query excluding the variable that is used only as base node
+ * of assignment indirection. The variable id assigned to this param
+ * should be same like resultVariable id, and this param should be
+ * used only once in query. When the variable is referenced by any
+ * other param, we should to do SELECT permission check for this variable
+ * too.
+ */
+ if (p->parambasenode)
+ {
+ Assert(!OidIsValid(root->glob->basenodeSessionVarid));
+ Assert(root->glob->resultVariable == p->paramvarid);
+
+ root->glob->basenodeSessionVarid = p->paramvarid;
+ }
+ else
+ {
+ if (p->paramvarid == root->glob->resultVariable)
+ root->glob->basenodeSessionVarSelectCheck = true;
+ }
+
+ return (Node *) p;
+ }
+
return (Node *) copyObject(p);
}
@@ -2194,7 +2309,10 @@ fix_alternative_subplan(PlannerInfo *root, AlternativeSubPlan *asplan,
* replacing Aggref nodes that should be replaced by initplan output Params,
* choosing the best implementation for AlternativeSubPlans,
* looking up operator opcode info for OpExpr and related nodes,
- * and adding OIDs from regclass Const nodes into root->glob->relationOids.
+ * adding OIDs from regclass Const nodes into root->glob->relationOids,
+ * assigning paramvarid to PARAM_VARIABLE params, and collecting the
+ * OIDs of session variables in the root->glob->sessionVariables list
+ * (paramvarid is the position of the session variable in this list).
*
* 'node': the expression to be modified
* 'rtoffset': how much to increment varnos by
@@ -2216,7 +2334,8 @@ fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec)
root->multiexpr_params != NIL ||
root->glob->lastPHId != 0 ||
root->minmax_aggs != NIL ||
- root->hasAlternativeSubPlans)
+ root->hasAlternativeSubPlans ||
+ root->hasSessionVariables)
{
return fix_scan_expr_mutator(node, &context);
}
@@ -3609,6 +3728,25 @@ record_plan_type_dependency(PlannerInfo *root, Oid typid)
}
}
+/*
+ * Record dependency on a session variable. The variable can be used as a
+ * session variable in an expression list, or as the target of a LET statement.
+ */
+static void
+record_plan_variable_dependency(PlannerInfo *root, Oid varid)
+{
+ PlanInvalItem *inval_item = makeNode(PlanInvalItem);
+
+ /* paramid is still session variable id */
+ inval_item->cacheId = VARIABLEOID;
+ inval_item->hashValue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ /* append this variable to global, register dependency */
+ root->glob->invalItems = lappend(root->glob->invalItems,
+ inval_item);
+}
+
/*
* extract_query_dependencies
* Given a rewritten, but not yet planned, query or queries
@@ -3694,9 +3832,9 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
}
/*
- * Ignore other utility statements, except those (such as EXPLAIN)
- * that contain a parsed-but-not-planned query. For those, we
- * just need to transfer our attention to the contained query.
+ * Ignore other utility statements, except those (such as EXPLAIN
+ * or LET) that contain a parsed-but-not-planned query. For those,
+ * we just need to transfer our attention to the contained query.
*/
query = UtilityContainsQuery(query->utilityStmt);
if (query == NULL)
@@ -3719,6 +3857,10 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
lappend_oid(context->glob->relationOids, rte->relid);
}
+ /* record dependency on the target variable of a LET command */
+ if (OidIsValid(query->resultVariable))
+ record_plan_variable_dependency(context, query->resultVariable);
+
/* And recurse into the query's subexpressions */
return query_tree_walker(query, extract_query_dependencies_walker,
context, 0);
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index bcc40dd5a84..6b7200487a6 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -1573,6 +1573,9 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
/* If subquery had any RLS conditions, now main query does too */
parse->hasRowSecurity |= subquery->hasRowSecurity;
+ /* if the subquery had session variables, the main query does too */
+ parse->hasSessionVariables |= subquery->hasSessionVariables;
+
/*
* subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
* hasTargetSRFs, so no work needed on those flags
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 43dfecfb47f..f60828f862e 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -24,6 +24,7 @@
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "commands/session_variable.h"
#include "executor/executor.h"
#include "executor/functions.h"
#include "funcapi.h"
@@ -934,6 +935,13 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
if (param->paramkind == PARAM_EXTERN)
return false;
+ /* we don't support passing session variables to workers */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
+ return true;
+ }
+
if (param->paramkind != PARAM_EXEC ||
!list_member_int(context->safe_param_ids, param->paramid))
{
@@ -2389,6 +2397,7 @@ convert_saop_to_hashed_saop_walker(Node *node, void *context)
* value of the Param.
* 2. Fold stable, as well as immutable, functions to constants.
* 3. Reduce PlaceHolderVar nodes to their contained expressions.
+ * 4. Current value of session variable can be used for estimation too.
*--------------------
*/
Node *
@@ -2515,6 +2524,27 @@ eval_const_expressions_mutator(Node *node,
}
}
}
+ else if (param->paramkind == PARAM_VARIABLE &&
+ context->estimate)
+ {
+ int16 typLen;
+ bool typByVal;
+ Datum pval;
+ bool isnull;
+
+ get_typlenbyval(param->paramtype,
+ &typLen, &typByVal);
+
+ pval = GetSessionVariable(param->paramvarid, &isnull);
+
+ return (Node *) makeConst(param->paramtype,
+ param->paramtypmod,
+ param->paramcollid,
+ (int) typLen,
+ pval,
+ isnull,
+ typByVal);
+ }
/*
* Not replaceable, so just copy the Param (no need to
@@ -4720,7 +4750,8 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
querytree->limitOffset ||
querytree->limitCount ||
querytree->setOperations ||
- list_length(querytree->targetList) != 1)
+ (list_length(querytree->targetList) != 1) ||
+ querytree->hasSessionVariables)
goto fail;
/* If the function result is composite, resolve it */
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 76f58b3aca3..725f678e2fa 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -25,9 +25,12 @@
#include "postgres.h"
#include "access/sysattr.h"
+#include "catalog/namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
@@ -51,6 +54,7 @@
#include "utils/backend_status.h"
#include "utils/builtins.h"
#include "utils/guc.h"
+#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
@@ -83,6 +87,8 @@ static Query *transformCreateTableAsStmt(ParseState *pstate,
CreateTableAsStmt *stmt);
static Query *transformCallStmt(ParseState *pstate,
CallStmt *stmt);
+static Query *transformLetStmt(ParseState *pstate,
+ LetStmt *stmt);
static void transformLockingClause(ParseState *pstate, Query *qry,
LockingClause *lc, bool pushedDown);
#ifdef DEBUG_NODE_TESTS_ENABLED
@@ -414,6 +420,7 @@ transformStmt(ParseState *pstate, Node *parseTree)
case T_UpdateStmt:
case T_DeleteStmt:
case T_MergeStmt:
+ case T_LetStmt:
(void) test_raw_expression_coverage(parseTree, NULL);
break;
default:
@@ -493,6 +500,11 @@ transformStmt(ParseState *pstate, Node *parseTree)
(CallStmt *) parseTree);
break;
+ case T_LetStmt:
+ result = transformLetStmt(pstate,
+ (LetStmt *) parseTree);
+ break;
+
default:
/*
@@ -545,6 +557,7 @@ stmt_requires_parse_analysis(RawStmt *parseTree)
case T_SelectStmt:
case T_ReturnStmt:
case T_PLAssignStmt:
+ case T_LetStmt:
result = true;
break;
@@ -653,6 +666,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1078,6 +1092,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1543,6 +1558,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, stmt->lockingClause)
{
@@ -1769,12 +1785,241 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
return qry;
}
+/*
+ * transformLetStmt -
+ * transform an Let Statement
+ */
+static Query *
+transformLetStmt(ParseState *pstate, LetStmt *stmt)
+{
+ Query *query;
+ Query *result;
+ List *exprList = NIL;
+ List *exprListCoer = NIL;
+ ListCell *lc;
+ ListCell *indirection_head = NULL;
+ Query *selectQuery;
+ Oid varid;
+ char *attrname = NULL;
+ bool not_unique;
+ bool is_rowtype;
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+ List *names = NULL;
+ int indirection_start;
+ int i = 0;
+
+ /* there can't be any outer WITH to worry about */
+ Assert(pstate->p_ctenamespace == NIL);
+
+ names = NamesFromList(stmt->target);
+
+ /* locks the variable with an AccessShareLock */
+ varid = IdentifyVariable(names, &attrname, ¬_unique, false);
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("target \"%s\" of LET command is ambiguous",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ if (!OidIsValid(varid))
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ /*
+ * Calculate start of possible position of an indirection in list, and
+ * when it is inside the list, store pointer on first node of indirection.
+ */
+ indirection_start = list_length(names) - (attrname ? 1 : 0);
+ if (list_length(stmt->target) > indirection_start)
+ indirection_head = list_nth_cell(stmt->target, indirection_start);
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod, &collid);
+
+ is_rowtype = type_is_rowtype(typid);
+
+ if (attrname && !is_rowtype)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("cannot assign to field \"%s\" of session variable \"%s.%s\" because its type %s is not a composite type",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->location)));
+
+ pstate->p_expr_kind = EXPR_KIND_LET_TARGET;
+
+ /* we need to postpone conversion of "unknown" to text */
+ pstate->p_resolve_unknowns = false;
+
+ selectQuery = transformStmt(pstate, stmt->query);
+
+ /* the grammar should have produced a SELECT */
+ Assert(IsA(selectQuery, Query) && selectQuery->commandType == CMD_SELECT);
+
+ /*
+ * Generate an expression list for the LET that selects all the non-resjunk
+ * columns from the subquery.
+ */
+ exprList = NIL;
+ foreach_node(TargetEntry, tle, selectQuery->targetList)
+ {
+ if (tle->resjunk)
+ continue;
+
+ exprList = lappend(exprList, tle->expr);
+ }
+
+ /* don't allow multicolumn result */
+ if (list_length(exprList) != 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg_plural("assignment expression returned %d column",
+ "assignment expression returned %d columns",
+ list_length(exprList),
+ list_length(exprList)),
+ parser_errposition(pstate,
+ exprLocation((Node *) exprList))));
+
+ exprListCoer = NIL;
+
+ foreach(lc, exprList)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ Expr *coerced_expr;
+ Oid exprtypid;
+
+ /* now we can read the type of the expression */
+ exprtypid = exprType((Node *) expr);
+
+ if (indirection_head)
+ {
+ bool targetIsArray;
+ char *targetName;
+ Param *param;
+
+ targetName = get_session_variable_name(varid);
+ targetIsArray = OidIsValid(get_element_type(typid));
+
+ pstate->p_hasSessionVariables = true;
+
+ param = makeNode(Param);
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+
+ /*
+ * The parameter used as basenode has to have special
+ * mark, because requires special access when we do
+ * SELECT access check.
+ */
+ param->parambasenode = true;
+
+ coerced_expr = (Expr *)
+ transformAssignmentIndirection(pstate,
+ (Node *) param,
+ targetName,
+ targetIsArray,
+ typid,
+ typmod,
+ InvalidOid,
+ stmt->target,
+ indirection_head,
+ (Node *) expr,
+ COERCION_ASSIGNMENT,
+ stmt->location);
+ }
+ else
+ coerced_expr = (Expr *)
+ coerce_to_target_type(pstate,
+ (Node *) expr,
+ exprtypid,
+ typid, typmod,
+ COERCION_ASSIGNMENT,
+ COERCE_IMPLICIT_CAST,
+ stmt->location);
+
+ if (coerced_expr == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("variable \"%s.%s\" is of type %s, but expression is of type %s",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid),
+ format_type_be(exprtypid)),
+ errhint("You will need to rewrite or cast the expression."),
+ parser_errposition(pstate, exprLocation((Node *) expr))));
+
+ exprListCoer = lappend(exprListCoer, coerced_expr);
+ }
+
+ /* generate query's target list using the computed list of expressions */
+ query = makeNode(Query);
+ query->commandType = CMD_SELECT;
+
+ foreach(lc, exprListCoer)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ TargetEntry *tle;
+
+ tle = makeTargetEntry(expr,
+ i + 1,
+ FigureColname((Node *) expr),
+ false);
+ query->targetList = lappend(query->targetList, tle);
+ }
+
+ /* done building the range table and jointree */
+ query->rtable = pstate->p_rtable;
+ query->jointree = makeFromExpr(pstate->p_joinlist, NULL);
+
+ query->hasTargetSRFs = pstate->p_hasTargetSRFs;
+ query->hasSubLinks = pstate->p_hasSubLinks;
+ query->hasSessionVariables = pstate->p_hasSessionVariables;
+
+ /* this is top-level query */
+ query->canSetTag = true;
+
+ /*
+ * Save target session variable ID. It is used later for
+ * acquiring an AccessShareLock on target variable, setting
+ * plan dependency and finally for creating VariableDestReceiver.
+ */
+ query->resultVariable = varid;
+
+ assign_query_collations(pstate, query);
+
+ /*
+ * The query is executed as utility command by nested executor call.
+ * Assigned queryId is required in this case.
+ */
+ if (IsQueryIdEnabled())
+ JumbleQuery(query);
+
+ stmt->query = (Node *) query;
+
+ /* represent the command as a utility Query */
+ result = makeNode(Query);
+ result->commandType = CMD_UTILITY;
+ result->utilityStmt = (Node *) stmt;
+
+ return result;
+}
+
/*
* transformSetOperationStmt -
* transforms a set-operations tree
@@ -2020,6 +2265,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, lockingClause)
{
@@ -2495,6 +2741,7 @@ transformReturnStmt(ParseState *pstate, ReturnStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2562,6 +2809,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2852,9 +3100,15 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
/*
* Transform the target reference. Typically we will get back a Param
* node, but there's no reason to be too picky about its type.
+ *
+ * Session variables should not be used as target of a PL/pgSQL assign
+ * statement. So we should use a dedicated expression kind and disallow
+ * session variables there. The dedicated context allows to eliminate
+ * undesirable warnings about the possibility of a target PL/pgSQL variable
+ * shadowing a session variable.
*/
target = transformExpr(pstate, (Node *) cref,
- EXPR_KIND_UPDATE_TARGET);
+ EXPR_KIND_ASSIGN_TARGET);
targettype = exprType(target);
targettypmod = exprTypmod(target);
targetcollation = exprCollation(target);
@@ -2896,6 +3150,10 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
*/
type_id = exprType((Node *) tle->expr);
+ /*
+ * For indirection processing and additional casts we can use expr_kind
+ * EXPR_KIND_UPDATE_TARGET.
+ */
pstate->p_expr_kind = EXPR_KIND_UPDATE_TARGET;
if (indirection)
@@ -3038,6 +3296,8 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
(LockingClause *) lfirst(l), false);
}
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
+
assign_query_collations(pstate, qry);
/* this must be done after collations, for reliable comparison of exprs */
@@ -3311,6 +3571,16 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt)
true,
stmt->funccall->location);
+ /*
+ * The arguments of CALL statement are evaluated by a direct expression
+ * executor call. This path is unsupported yet, so block it. It will be
+ * enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
assign_expr_collations(pstate, node);
fexpr = castNode(FuncExpr, node);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 6c95950b99b..04251bba456 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -297,7 +297,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
DropTransformStmt
DropUserMappingStmt ExplainStmt FetchStmt
GrantStmt GrantRoleStmt ImportForeignSchemaStmt IndexStmt InsertStmt
- ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
+ LetStmt ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
CreateFunctionStmt AlterFunctionStmt ReindexStmt RemoveAggrStmt
RemoveFuncStmt RemoveOperStmt RenameStmt ReturnStmt RevokeStmt RevokeRoleStmt
RuleActionStmt RuleActionStmtOrEmpty RuleStmt
@@ -742,7 +742,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
KEEP KEY KEYS
LABEL LANGUAGE LARGE_P LAST_P LATERAL_P
- LEADING LEAKPROOF LEAST LEFT LEVEL LIKE LIMIT LISTEN LOAD LOCAL
+ LEADING LEAKPROOF LEAST LEFT LET LEVEL LIKE LIMIT LISTEN LOAD LOCAL
LOCALTIME LOCALTIMESTAMP LOCATION LOCK_P LOCKED LOGGED
MAPPING MATCH MATCHED MATERIALIZED MAXVALUE MERGE MERGE_ACTION METHOD
@@ -1089,6 +1089,7 @@ stmt:
| ImportForeignSchemaStmt
| IndexStmt
| InsertStmt
+ | LetStmt
| ListenStmt
| RefreshMatViewStmt
| LoadStmt
@@ -12845,6 +12846,38 @@ opt_hold: /* EMPTY */ { $$ = 0; }
| WITHOUT HOLD { $$ = 0; }
;
+/*****************************************************************************
+ *
+ * QUERY:
+ * LET STATEMENT
+ *
+ *****************************************************************************/
+LetStmt: LET ColId opt_indirection '=' a_expr
+ {
+ LetStmt *n = makeNode(LetStmt);
+ SelectStmt *select;
+ ResTarget *res;
+
+ n->target = lcons(makeString($2),
+ check_indirection($3, yyscanner));
+
+ select = makeNode(SelectStmt);
+ res = makeNode(ResTarget);
+
+ /* create target list for implicit query */
+ res->name = NULL;
+ res->indirection = NIL;
+ res->val = (Node *) $5;
+ res->location = @5;
+
+ select->targetList = list_make1(res);
+ n->query = (Node *) select;
+
+ n->location = @2;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* QUERY:
@@ -17916,6 +17949,7 @@ unreserved_keyword:
| LARGE_P
| LAST_P
| LEAKPROOF
+ | LET
| LEVEL
| LISTEN
| LOAD
@@ -18529,6 +18563,7 @@ bare_label_keyword:
| LEAKPROOF
| LEAST
| LEFT
+ | LET
| LEVEL
| LIKE
| LISTEN
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 9e567f3cc45..4737b04d171 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -580,6 +580,11 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
+
/*
* There is intentionally no default: case here, so that the
* compiler will warn if we add a new ParseExprKind without
@@ -970,6 +975,10 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
case EXPR_KIND_CYCLE_MARK:
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index bad1df732ea..4f208c7efdd 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -17,6 +17,7 @@
#include "catalog/pg_aggregate.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
@@ -33,11 +34,13 @@
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "parser/parse_type.h"
+#include "storage/lmgr.h"
#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/timestamp.h"
+#include "utils/typcache.h"
#include "utils/xml.h"
/* GUC parameters */
@@ -106,6 +109,9 @@ static Expr *make_distinct_op(ParseState *pstate, List *opname,
Node *ltree, Node *rtree, int location);
static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
+static Node *makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location);
/*
@@ -499,6 +505,89 @@ transformIndirection(ParseState *pstate, A_Indirection *ind)
return result;
}
+/*
+ * Returns true if the given expression kind is valid for session variables.
+ * Session variables can be used everywhere where external parameters can be
+ * used. Session variables are not allowed in DDL commands or in constraints.
+ *
+ * An identifier can be parsed as a session variable only for expression kinds
+ * where session variables are allowed. This is the primary usage of this
+ * function.
+ *
+ * The second usage of this function is to decide whether a "column does not
+ * exist" or a "column or variable does not exist" error message should be
+ * printed. When we are in an expression where session variables cannot be
+ * used, we raise the first form of error message.
+ */
+static bool
+expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
+{
+ bool result = false;
+
+ switch (p_expr_kind)
+ {
+ case EXPR_KIND_NONE:
+ Assert(false); /* can't happen */
+ return false;
+
+ /* session variables allowed */
+ case EXPR_KIND_OTHER:
+ case EXPR_KIND_JOIN_ON:
+ case EXPR_KIND_FROM_SUBSELECT:
+ case EXPR_KIND_FROM_FUNCTION:
+ case EXPR_KIND_WHERE:
+ case EXPR_KIND_HAVING:
+ case EXPR_KIND_FILTER:
+ case EXPR_KIND_WINDOW_PARTITION:
+ case EXPR_KIND_WINDOW_ORDER:
+ case EXPR_KIND_WINDOW_FRAME_RANGE:
+ case EXPR_KIND_WINDOW_FRAME_ROWS:
+ case EXPR_KIND_WINDOW_FRAME_GROUPS:
+ case EXPR_KIND_SELECT_TARGET:
+ case EXPR_KIND_INSERT_TARGET:
+ case EXPR_KIND_UPDATE_SOURCE:
+ case EXPR_KIND_UPDATE_TARGET:
+ case EXPR_KIND_MERGE_WHEN:
+ case EXPR_KIND_MERGE_RETURNING:
+ case EXPR_KIND_GROUP_BY:
+ case EXPR_KIND_ORDER_BY:
+ case EXPR_KIND_DISTINCT_ON:
+ case EXPR_KIND_LIMIT:
+ case EXPR_KIND_OFFSET:
+ case EXPR_KIND_RETURNING:
+ case EXPR_KIND_VALUES:
+ case EXPR_KIND_VALUES_SINGLE:
+ case EXPR_KIND_ALTER_COL_TRANSFORM:
+ case EXPR_KIND_EXECUTE_PARAMETER:
+ case EXPR_KIND_POLICY:
+ case EXPR_KIND_CALL_ARGUMENT:
+ case EXPR_KIND_COPY_WHERE:
+ case EXPR_KIND_LET_TARGET:
+ result = true;
+ break;
+
+ /* session variables not allowed */
+ case EXPR_KIND_CHECK_CONSTRAINT:
+ case EXPR_KIND_DOMAIN_CHECK:
+ case EXPR_KIND_COLUMN_DEFAULT:
+ case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_INDEX_EXPRESSION:
+ case EXPR_KIND_INDEX_PREDICATE:
+ case EXPR_KIND_STATS_EXPRESSION:
+ case EXPR_KIND_TRIGGER_WHEN:
+ case EXPR_KIND_PARTITION_BOUND:
+ case EXPR_KIND_PARTITION_EXPRESSION:
+ case EXPR_KIND_GENERATED_COLUMN:
+ case EXPR_KIND_JOIN_USING:
+ case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ result = false;
+ break;
+ }
+
+ return result;
+}
+
/*
* Transform a ColumnRef.
*
@@ -575,6 +664,8 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
case EXPR_KIND_COPY_WHERE:
case EXPR_KIND_GENERATED_COLUMN:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
@@ -847,8 +938,61 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
}
/*
- * Throw error if no translation found.
+ * There are contexts where session variables are not allowed. We don't
+ * need to identify session variables in such a context, but identifying
+ * them allows us to raise meaningful error messages like "you cannot use
+ * session variables here".
*/
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind))
+ {
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* -----
+ * Session variables are shadowed by columns, routine variables or
+ * routine arguments. We certainly don't want to use a session variable
+ * when it is exactly shadowed, but a RTE like this is conceivable:
+ *
+ * CREATE TYPE t AS (c int);
+ * CREATE VARIABLE foo AS t;
+ * CREATE TABLE foo(a int, b int);
+ *
+ * SELECT foo.a, foo.b, foo.c FROM foo;
+ *
+ * However, that is very confusing, so we disallow it. We don't try to
+ * identify a variable if we know that it would be shadowed.
+ * -----
+ */
+ if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ {
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(cref->fields)),
+ parser_errposition(pstate, cref->location)));
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ node = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, cref->location);
+ }
+ }
+ }
+
+ /* throw an error if no translation was found */
if (node == NULL)
{
switch (crerr)
@@ -880,6 +1024,75 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
return node;
}
+/*
+ * Generate param variable for reference to session variable
+ */
+static Node *
+makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location)
+{
+ Param *param;
+
+ param = makeNode(Param);
+
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+ param->paramcollid = collid;
+
+ pstate->p_hasSessionVariables = true;
+
+ if (attrname != NULL)
+ {
+ TupleDesc tupdesc;
+ int i;
+
+ tupdesc = lookup_rowtype_tupdesc_noerror(typid, typmod, true);
+ if (!tupdesc)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("variable \"%s.%s\" is of type \"%s\", which is not a composite type",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, location)));
+
+ for (i = 0; i < tupdesc->natts; i++)
+ {
+ Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+ if (strcmp(attrname, NameStr(att->attname)) == 0 &&
+ !att->attisdropped)
+ {
+ /* success, so generate a FieldSelect expression */
+ FieldSelect *fselect = makeNode(FieldSelect);
+
+ fselect->arg = (Expr *) param;
+ fselect->fieldnum = i + 1;
+ fselect->resulttype = att->atttypid;
+ fselect->resulttypmod = att->atttypmod;
+ /* save attribute's collation for parse_collate.c */
+ fselect->resultcollid = att->attcollation;
+
+ ReleaseTupleDesc(tupdesc);
+ return (Node *) fselect;
+ }
+ }
+
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_COLUMN),
+ errmsg("could not identify column \"%s\" in variable \"%s.%s\"",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ parser_errposition(pstate, location)));
+ }
+
+ return (Node *) param;
+}
+
static Node *
transformParamRef(ParseState *pstate, ParamRef *pref)
{
@@ -1815,6 +2028,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_VALUES:
case EXPR_KIND_VALUES_SINGLE:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
case EXPR_KIND_CHECK_CONSTRAINT:
@@ -1858,6 +2072,9 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_GENERATED_COLUMN:
err = _("cannot use subquery in column generation expression");
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ err = _("cannot use subquery as target of assign statement");
+ break;
/*
* There is intentionally no default: case here, so that the
@@ -3207,6 +3424,10 @@ ParseExprKindName(ParseExprKind exprKind)
return "GENERATED AS";
case EXPR_KIND_CYCLE_MARK:
return "CYCLE";
+ case EXPR_KIND_ASSIGN_TARGET:
+ return "ASSIGN";
+ case EXPR_KIND_LET_TARGET:
+ return "LET";
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index 583bbbf232f..dc25f6dcd0e 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2656,6 +2656,8 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location)
err = _("set-returning functions are not allowed in column generation expressions");
break;
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
errkind = true;
break;
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
index 51d7703eff7..244efcddf32 100644
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -405,6 +405,7 @@ transformMergeStmt(ParseState *pstate, MergeStmt *stmt)
qry->hasTargetSRFs = false;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c
index b620766c938..b2f764b657f 100644
--- a/src/backend/tcop/dest.c
+++ b/src/backend/tcop/dest.c
@@ -38,6 +38,7 @@
#include "executor/functions.h"
#include "executor/tqueue.h"
#include "executor/tstoreReceiver.h"
+#include "executor/svariableReceiver.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
@@ -155,6 +156,9 @@ CreateDestReceiver(CommandDest dest)
case DestExplainSerialize:
return CreateExplainSerializeDestReceiver(NULL);
+
+ case DestVariable:
+ return CreateVariableDestReceiver(InvalidOid);
}
/* should never get here */
@@ -191,6 +195,7 @@ EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_o
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -237,6 +242,7 @@ NullCommand(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -281,6 +287,7 @@ ReadyForQuery(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 99a51877d34..7a508a3644f 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -49,6 +49,7 @@
#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
+#include "commands/session_variable.h"
#include "commands/subscriptioncmds.h"
#include "commands/tablecmds.h"
#include "commands/tablespace.h"
@@ -235,6 +236,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CallStmt:
case T_DoStmt:
+ case T_LetStmt:
{
/*
* Commands inside the DO block or the called procedure might
@@ -1067,6 +1069,11 @@ standard_ProcessUtility(PlannedStmt *pstmt,
break;
}
+ case T_LetStmt:
+ ExecuteLetStmt(pstate, (LetStmt *) parsetree, params,
+ queryEnv, qc);
+ break;
+
default:
/* All other statement types have event trigger support */
ProcessUtilitySlow(pstate, pstmt, queryString,
@@ -2206,6 +2213,10 @@ UtilityContainsQuery(Node *parsetree)
return UtilityContainsQuery(qry->utilityStmt);
return qry;
+ case T_LetStmt:
+ qry = castNode(Query, ((LetStmt *) parsetree)->query);
+ return qry;
+
default:
return NULL;
}
@@ -2404,6 +2415,10 @@ CreateCommandTag(Node *parsetree)
tag = CMDTAG_SELECT;
break;
+ case T_LetStmt:
+ tag = CMDTAG_LET;
+ break;
+
/* utility statements --- same whether raw or cooked */
case T_TransactionStmt:
{
@@ -3289,6 +3304,7 @@ GetCommandLogLevel(Node *parsetree)
break;
case T_PLAssignStmt:
+ case T_LetStmt:
lev = LOGSTMT_ALL;
break;
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index d11a8a20eea..de503d38f19 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -37,6 +37,7 @@
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablespace.h"
#include "common/keywords.h"
@@ -531,6 +532,7 @@ static char *generate_function_name(Oid funcid, int nargs,
static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2);
static void add_cast_to(StringInfo buf, Oid typid);
static char *generate_qualified_type_name(Oid typid);
+static char *generate_session_variable_name(Oid varid);
static text *string_to_text(char *str);
static char *flatten_reloptions(Oid relid);
static void get_reloptions(StringInfo buf, Datum reloptions);
@@ -8677,6 +8679,14 @@ get_parameter(Param *param, deparse_context *context)
return;
}
+ /* translate paramvarid to session variable name */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ return;
+ }
+
/*
* Alternatively, maybe it's a subplan output, which we print as a
* reference to the subplan. (We could drill down into the subplan and
@@ -13484,6 +13494,42 @@ generate_collation_name(Oid collid)
return result;
}
+/*
+ * generate_session_variable_name
+ * Compute the name to display for a session variable specified by OID
+ *
+ * The result includes all necessary quoting and schema-prefixing.
+ */
+static char *
+generate_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+ char *nspname;
+ char *result;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = NameStr(varform->varname);
+
+ if (!VariableIsVisible(varid))
+ nspname = get_namespace_name_or_temp(varform->varnamespace);
+ else
+ nspname = NULL;
+
+ result = quote_qualified_identifier(nspname, varname);
+
+ ReleaseSysCache(tup);
+
+ return result;
+}
+
/*
* Given a C string, produce a TEXT datum.
*
diff --git a/src/backend/utils/cache/plancache.c b/src/backend/utils/cache/plancache.c
index 6c2979d5c82..88574766861 100644
--- a/src/backend/utils/cache/plancache.c
+++ b/src/backend/utils/cache/plancache.c
@@ -58,6 +58,7 @@
#include "access/transam.h"
#include "catalog/namespace.h"
+#include "catalog/pg_variable.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
@@ -163,6 +164,7 @@ InitPlanCache(void)
CacheRegisterSyscacheCallback(AMOPOPID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNSERVEROID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNDATAWRAPPEROID, PlanCacheSysCallback, (Datum) 0);
+ CacheRegisterSyscacheCallback(VARIABLEOID, PlanCacheObjectCallback, (Datum) 0);
}
/*
@@ -2050,17 +2052,32 @@ ScanQueryForLocks(Query *parsetree, bool acquire)
/*
* Recurse into sublink subqueries, too. But we already did the ones in
- * the rtable and cteList.
+ * the rtable and cteList. We need to force a recursive call for session
+ * variables too, to find and lock variables used in the query (see
+ * ScanQueryWalker).
*/
- if (parsetree->hasSubLinks)
+ if (parsetree->hasSubLinks ||
+ parsetree->hasSessionVariables)
{
query_tree_walker(parsetree, ScanQueryWalker, &acquire,
QTW_IGNORE_RC_SUBQUERIES);
}
+
+ /* process session variables */
+ if (OidIsValid(parsetree->resultVariable))
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ }
}
/*
- * Walker to find sublink subqueries for ScanQueryForLocks
+ * Walker to find sublink subqueries or referenced session variables
+ * for ScanQueryForLocks
*/
static bool
ScanQueryWalker(Node *node, bool *acquire)
@@ -2075,6 +2092,20 @@ ScanQueryWalker(Node *node, bool *acquire)
ScanQueryForLocks(castNode(Query, sub->subselect), *acquire);
/* Fall through to process lefthand args of SubLink */
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ }
+ }
/*
* Do NOT recurse into Query nodes, because ScanQueryForLocks already
@@ -2205,7 +2236,9 @@ PlanCacheRelCallback(Datum arg, Oid relid)
/*
* PlanCacheObjectCallback
- * Syscache inval callback function for PROCOID and TYPEOID caches
+ * Syscache inval callback function for TYPEOID, PROCOID, NAMESPACEOID,
+ * OPEROID, AMOPOPID, FOREIGNSERVEROID, FOREIGNDATAWRAPPEROID and
+ * VARIABLEOID caches.
*
* Invalidate all plans mentioning the object with the specified hash value,
* or all plans mentioning any member of this cache if hashvalue == 0.
diff --git a/src/backend/utils/fmgr/fmgr.c b/src/backend/utils/fmgr/fmgr.c
index 782291d9998..093622fbdc4 100644
--- a/src/backend/utils/fmgr/fmgr.c
+++ b/src/backend/utils/fmgr/fmgr.c
@@ -2026,9 +2026,13 @@ get_call_expr_arg_stable(Node *expr, int argnum)
*/
if (IsA(arg, Const))
return true;
- if (IsA(arg, Param) &&
- ((Param *) arg)->paramkind == PARAM_EXTERN)
- return true;
+ if (IsA(arg, Param))
+ {
+ Param *p = (Param *) arg;
+
+ if (p->paramkind == PARAM_EXTERN || p->paramkind == PARAM_VARIABLE)
+ return true;
+ }
return false;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 84907f76c0a..dfe821f4b60 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1228,8 +1228,8 @@ static const char *const sql_commands[] = {
"ABORT", "ALTER", "ANALYZE", "BEGIN", "CALL", "CHECKPOINT", "CLOSE", "CLUSTER",
"COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE",
"DELETE FROM", "DISCARD", "DO", "DROP", "END", "EXECUTE", "EXPLAIN",
- "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LISTEN", "LOAD", "LOCK",
- "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
+ "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LET",
+ "LISTEN", "LOAD", "LOCK", "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
"REASSIGN", "REFRESH MATERIALIZED VIEW", "REINDEX", "RELEASE",
"RESET", "REVOKE", "ROLLBACK",
"SAVEPOINT", "SECURITY LABEL", "SELECT", "SET", "SHOW", "START",
@@ -4689,6 +4689,14 @@ match_previous_words(int pattern_id,
else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES"))
COMPLETE_WITH("(");
+/* LET */
+ /* If prev. word is LET suggest a list of variables */
+ else if (Matches("LET"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ /* Complete LET <variable> with "=" */
+ else if (TailMatches("LET", MatchAny))
+ COMPLETE_WITH("=");
+
/* LOCK */
/* Complete LOCK [TABLE] [ONLY] with a list of tables */
else if (Matches("LOCK"))
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index bdac0c13bec..5060b8c9490 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -174,6 +174,7 @@ extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
extern List *NamesFromList(List *names);
extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+extern Oid IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror);
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 3d3c6eb24b5..5b45be5afaf 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -18,6 +18,7 @@
#ifndef PG_VARIABLE_H
#define PG_VARIABLE_H
+#include "access/xlogdefs.h"
#include "catalog/genbki.h"
#include "catalog/objectaddress.h"
#include "catalog/pg_variable_d.h"
@@ -35,6 +36,14 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* OID of entry in pg_type for variable's type */
Oid vartype BKI_LOOKUP(pg_type);
+ /*
+ * Used for identity check [oid, create_lsn].
+ *
+ * This column of the 8-byte XlogRecPtr type should be at an address that
+ * is divisible by 8, but before any column of type NameData.
+ */
+ XLogRecPtr varcreate_lsn;
+
/* variable name */
NameData varname;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
new file mode 100644
index 00000000000..2391b9ad443
--- /dev/null
+++ b/src/include/commands/session_variable.h
@@ -0,0 +1,30 @@
+/*-------------------------------------------------------------------------
+ *
+ * sessionvariable.h
+ * prototypes for sessionvariable.c.
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/commands/session_variable.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SESSIONVARIABLE_H
+#define SESSIONVARIABLE_H
+
+#include "nodes/params.h"
+#include "nodes/parsenodes.h"
+#include "parser/parse_node.h"
+#include "tcop/cmdtag.h"
+#include "utils/queryenvironment.h"
+
+extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
+extern Datum GetSessionVariable(Oid varid, bool *isNull);
+
+extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
+ QueryEnvironment *queryEnv, QueryCompletion *qc);
+
+#endif
diff --git a/src/include/executor/svariableReceiver.h b/src/include/executor/svariableReceiver.h
new file mode 100644
index 00000000000..db44d8b94c6
--- /dev/null
+++ b/src/include/executor/svariableReceiver.h
@@ -0,0 +1,22 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.h
+ * prototypes for svariableReceiver.c
+ *
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/executor/svariableReceiver.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SVARIABLE_RECEIVER_H
+#define SVARIABLE_RECEIVER_H
+
+#include "tcop/dest.h"
+
+extern DestReceiver *CreateVariableDestReceiver(Oid varid);
+
+#endif /* SVARIABLE_RECEIVER_H */
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index a323fa98bbb..1b8ad640922 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -636,6 +636,16 @@ typedef struct AsyncRequest
* tuples) */
} AsyncRequest;
+/* ----------------
+ * SessionVariableValue
+ * ----------------
+ */
+typedef struct SessionVariableValue
+{
+ bool isnull;
+ Datum value;
+} SessionVariableValue;
+
/* ----------------
* EState information
*
@@ -696,6 +706,10 @@ typedef struct EState
ParamListInfo es_param_list_info; /* values of external params */
ParamExecData *es_param_exec_vals; /* values of internal params */
+ /* Session variables info: */
+ int es_num_session_variables; /* number of used variables */
+ SessionVariableValue *es_session_variables; /* array of copies of values */
+
QueryEnvironment *es_queryEnv; /* query environment */
/* Other working state: */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 9858034ccf6..40f04098104 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -142,6 +142,9 @@ typedef struct Query
*/
int resultRelation pg_node_attr(query_jumble_ignore);
+ /* target variable of LET statement */
+ Oid resultVariable;
+
/* has aggregates in tlist or havingQual */
bool hasAggs pg_node_attr(query_jumble_ignore);
/* has window functions in tlist */
@@ -162,6 +165,8 @@ typedef struct Query
bool hasRowSecurity pg_node_attr(query_jumble_ignore);
/* parser has added an RTE_GROUP RTE */
bool hasGroupRTE pg_node_attr(query_jumble_ignore);
+ /* uses session variables */
+ bool hasSessionVariables pg_node_attr(query_jumble_ignore);
/* is a RETURN statement */
bool isReturn pg_node_attr(query_jumble_ignore);
@@ -2144,6 +2149,18 @@ typedef struct MergeStmt
ParseLoc stmt_len; /* length in bytes; 0 means "rest of string" */
} MergeStmt;
+/* ----------------------
+ * Let Statement
+ * ----------------------
+ */
+typedef struct LetStmt
+{
+ NodeTag type;
+ List *target; /* target variable */
+ Node *query; /* source expression */
+ ParseLoc location;
+} LetStmt;
+
/* ----------------------
* Select Statement
*
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index fbf05322c75..b4988396a1c 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -179,6 +179,18 @@ typedef struct PlannerGlobal
/* partition descriptors */
PartitionDirectory partition_directory pg_node_attr(read_write_ignore);
+
+ /* list of used session variables */
+ List *sessionVariables;
+
+ /* Oid of session variable used like target of LET command */
+ Oid resultVariable;
+
+ /* oid of session variable used like base node for assignment indirection */
+ Oid basenodeSessionVarid;
+
+ /* true, if we do SELECT permission check on basenodeSessionVarid */
+ bool basenodeSessionVarSelectCheck;
} PlannerGlobal;
/* macro for fetching the Plan associated with a SubPlan node */
@@ -529,6 +541,8 @@ struct PlannerInfo
bool placeholdersFrozen;
/* true if planning a recursive WITH item */
bool hasRecursion;
+ /* true if session variables were used */
+ bool hasSessionVariables;
/*
* The rangetable index for the RTE_GROUP RTE, or 0 if there is no
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index bf1f25c0dba..1f739dc6140 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -128,6 +128,15 @@ typedef struct PlannedStmt
/* non-null if this is utility stmt */
Node *utilityStmt;
+ List *sessionVariables; /* OIDs for PARAM_VARIABLE Params */
+
+ /*
+ * The oid of session variable execluded from permission check.
+ * This session variable is used as base node of assignment indirection
+ * (and it is used only there).
+ */
+ int exclSelectPermCheckVarid;
+
/* statement location in source string (copied from Query) */
/* start location, or -1 if unknown */
ParseLoc stmt_location;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index d0576da3e25..24033045746 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -378,6 +378,9 @@ typedef struct Const
* of the `paramid' field contain the SubLink's subLinkId, and
* the low-order 16 bits contain the column number. (This type
* of Param is also converted to PARAM_EXEC during planning.)
+ *
+ * PARAM_VARIABLE: The parameter is a reference to a session variable
+ * (paramvarid holds the variable's OID).
*/
typedef enum ParamKind
{
@@ -385,6 +388,7 @@ typedef enum ParamKind
PARAM_EXEC,
PARAM_SUBLINK,
PARAM_MULTIEXPR,
+ PARAM_VARIABLE,
} ParamKind;
typedef struct Param
@@ -397,6 +401,16 @@ typedef struct Param
int32 paramtypmod pg_node_attr(query_jumble_ignore);
/* OID of collation, or InvalidOid if none */
Oid paramcollid pg_node_attr(query_jumble_ignore);
+ /* OID of session variable if it is used */
+ Oid paramvarid pg_node_attr(query_jumble_ignore);
+
+ /*
+ * true if param is used as base node of assignment indirection
+ * (when target of LET statement is an array field or an record field).
+ * For this param we do not check SELECT access right, because this
+ * param is used just for execution of UPDATE operation.
+ */
+ bool parambasenode;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index 5a930199611..7a3b522b5ff 100644
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -131,4 +131,6 @@ extern void record_plan_function_dependency(PlannerInfo *root, Oid funcid);
extern void record_plan_type_dependency(PlannerInfo *root, Oid typid);
extern bool extract_query_dependencies_walker(Node *node, PlannerInfo *context);
+extern void pull_up_has_session_variables(PlannerInfo *root);
+
#endif /* PLANMAIN_H */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 793ace526df..431167f6b43 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -257,6 +257,7 @@ PG_KEYWORD("leading", LEADING, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("leakproof", LEAKPROOF, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("least", LEAST, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("left", LEFT, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("let", LET, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("level", LEVEL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("like", LIKE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("limit", LIMIT, RESERVED_KEYWORD, AS_LABEL)
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 994284019fb..0b7b69a4159 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -82,6 +82,8 @@ typedef enum ParseExprKind
EXPR_KIND_COPY_WHERE, /* WHERE condition in COPY FROM */
EXPR_KIND_GENERATED_COLUMN, /* generation expression for a column */
EXPR_KIND_CYCLE_MARK, /* cycle mark value */
+ EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */
+ EXPR_KIND_LET_TARGET, /* LET target */
} ParseExprKind;
@@ -244,6 +246,7 @@ struct ParseState
bool p_hasTargetSRFs;
bool p_hasSubLinks;
bool p_hasModifyingCTE;
+ bool p_hasSessionVariables;
Node *p_last_srf; /* most recent set-returning func/op found */
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index ea86954dded..22082c30008 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -186,6 +186,7 @@ PG_CMDTAG(CMDTAG_GRANT, "GRANT", true, false, false)
PG_CMDTAG(CMDTAG_GRANT_ROLE, "GRANT ROLE", false, false, false)
PG_CMDTAG(CMDTAG_IMPORT_FOREIGN_SCHEMA, "IMPORT FOREIGN SCHEMA", true, false, false)
PG_CMDTAG(CMDTAG_INSERT, "INSERT", false, false, true)
+PG_CMDTAG(CMDTAG_LET, "LET", false, false, false)
PG_CMDTAG(CMDTAG_LISTEN, "LISTEN", false, false, false)
PG_CMDTAG(CMDTAG_LOAD, "LOAD", false, false, false)
PG_CMDTAG(CMDTAG_LOCK_TABLE, "LOCK TABLE", false, false, false)
diff --git a/src/include/tcop/dest.h b/src/include/tcop/dest.h
index 00c092e3d7c..6ce3ea0e617 100644
--- a/src/include/tcop/dest.h
+++ b/src/include/tcop/dest.h
@@ -97,6 +97,7 @@ typedef enum
DestTransientRel, /* results sent to transient relation */
DestTupleQueue, /* results sent to tuple queue */
DestExplainSerialize, /* results are serialized and discarded */
+ DestVariable, /* results sent to session variable */
} CommandDest;
/* ----------------
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index d4377ceecbf..cb282404c1a 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8264,7 +8264,8 @@ exec_is_simple_query(PLpgSQL_expr *expr)
query->sortClause ||
query->limitOffset ||
query->limitCount ||
- query->setOperations)
+ query->setOperations ||
+ query->hasSessionVariables)
return false;
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index c36660ce6d3..f22467186e3 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -431,3 +431,1235 @@ DROP VARIABLE public.var1;
DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+-- check access rights
+CREATE ROLE regress_noowner;
+CREATE VARIABLE var1 AS int;
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+-- should fail
+SET ROLE TO regress_noowner;
+SELECT var1;
+ERROR: permission denied for session variable var1
+SELECT sqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: SQL function "sqlfx" statement 1
+SELECT plpgsqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "$1 + var1"
+PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
+-- should be ok
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+-- should be ok
+SET ROLE TO regress_noowner;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+DROP ROLE regress_noowner;
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- start a new session
+\c
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- should fail, dependency
+DROP VARIABLE var1;
+ERROR: cannot drop session variable var1 because other objects depend on it
+DETAIL: view test_view depends on session variable var1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+NOTICE: drop cascades to view test_view
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+LET var1 = 'str1';
+LET var2 = 'str2';
+SELECT sqlfx1(sqlfx2('Hello'));
+ sqlfx1
+-------------------
+ str1, str2, Hello
+(1 row)
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+ QUERY PLAN
+------------------------------------------------------
+ Result
+ Output: sqlfx1(sqlfx2('Hello'::character varying))
+(2 rows)
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+SET plan_cache_mode TO force_generic_plan;
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 3.14
+(1 row)
+
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 6.28
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 9.42
+(1 row)
+
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 12.56
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+ERROR: function plpgsqlfx2() does not exist
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+SET plan_cache_mode TO DEFAULT;
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 1
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 55
+DROP VARIABLE var1;
+DROP TABLE testvar;
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+NOTICE: result array: {1,2,3,4,5,6,7,8,9,10}
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+-- should not crash (but is not supported yet)
+CALL p(v);
+ERROR: session variable cannot be used as an argument
+DO $$ BEGIN CALL p(v); END $$;
+ERROR: session variable cannot be used as an argument
+CONTEXT: SQL statement "CALL p(v)"
+PL/pgSQL function inline_code_block line 1 at CALL
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+-- should fail
+EXECUTE ptest(v);
+ERROR: session variable cannot be used as an argument
+DEALLOCATE ptest;
+DROP VARIABLE v;
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+-- should fail
+LET var1 = pi();
+ERROR: session variable "var1" doesn't exist
+LINE 1: LET var1 = pi();
+ ^
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+ var1
+------------------
+ 3.14159265358979
+(1 row)
+
+SET search_path TO svartest;
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+ var1
+------------------
+ 13.1415926535898
+(1 row)
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to session variable svartest.var1
+CREATE VARIABLE var1 AS text;
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+SELECT var1;
+ var1
+-------
+ hello
+(1 row)
+
+DROP VARIABLE var1;
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+-- should fail
+SELECT var1;
+ERROR: domain int_domain does not allow null values
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+ var1
+------
+ 1000
+(1 row)
+
+-- should fail
+LET var1 = 10;
+ERROR: value for domain int_domain violates check constraint "int_domain_check"
+-- should fail
+LET var1 = NULL;
+ERROR: domain int_domain does not allow null values
+-- note - domain defaults are not supported yet (like PLpgSQL)
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+ var1
+----------------------------------------
+ {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+(1 row)
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+DROP VARIABLE var1;
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+ var1
+------
+ 100
+(1 row)
+
+SET search_path to public, svartest;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table foo
+drop cascades to session variable var1
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+LET var2[var1] = 0;
+SELECT var2;
+ var2
+-----------
+ [2:2]={0}
+(1 row)
+
+DROP VARIABLE var1, var2;
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+SELECT var2;
+ var2
+------
+ {}
+(1 row)
+
+DROP VARIABLE var1, var2;
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+ERROR: syntax error at or near "LET"
+LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x;
+ ^
+-- should be ok
+LET var1 = generate_series(1, 1);
+-- should fail
+LET var1 = generate_series(1, 2);
+ERROR: expression returned more than one row
+LET var1 = generate_series(1, 0);
+ERROR: expression returned no rows
+DROP VARIABLE var1;
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+SELECT v1;
+ v1
+------------
+ (1,2,3.00)
+(1 row)
+
+SELECT v2;
+ v2
+---------------
+ (10,20,31.40)
+(1 row)
+
+SELECT (v1).*;
+ x | y | z
+---+---+------
+ 1 | 2 | 3.00
+(1 row)
+
+SELECT (v2).*;
+ x | y | z
+----+----+-------
+ 10 | 20 | 31.40
+(1 row)
+
+SELECT v1.x + v1.z;
+ ?column?
+----------
+ 4.00
+(1 row)
+
+SELECT v2.x + v2.z;
+ ?column?
+----------
+ 41.40
+(1 row)
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail
+SELECT v2.x;
+ERROR: permission denied for session variable v2
+SET ROLE TO DEFAULT;
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+ERROR: improper qualified name (too many dotted names): nodb.noschema.novar.nofield.nosubfield
+LET nodb.noschema.novar.nofield = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar.nofield
+LET nodb.noschema.novar = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar
+CREATE TYPE t1 AS (a int, b numeric, c text);
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+ v1
+----------------------------
+ (1,3.14159265358979,hello)
+(1 row)
+
+LET v1.b = 10.2222;
+SELECT v1;
+ v1
+-------------------
+ (1,10.2222,hello)
+(1 row)
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1
+LINE 1: LET v1.x = 10;
+ ^
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+ERROR: assignment expression returned 3 columns
+LINE 1: LET v1 = (NULL::t1).*;
+ ^
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+ v1
+-------------
+ (1,10.2222)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+ v1
+--------------
+ (1,10.2222,)
+(1 row)
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+ v1
+--------------
+ (10,10.3,20)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+ v1
+---------
+ (10,20)
+(1 row)
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+ERROR: cannot alter type "t1" because session variable "public.v1" uses it
+DROP VARIABLE v1;
+DROP TYPE t1;
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+ var1
+----------------------------------
+ (10,3.14159265358979,05-26-2023)
+(1 row)
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+ERROR: cannot alter table "svar_test" because session variable "public.var1" uses it
+-- should fail
+DROP TABLE svar_test;
+ERROR: cannot drop table svar_test because other objects depend on it
+DETAIL: session variable var1 depends on type svar_test
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+CREATE ROLE regress_var_test_role;
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+-- should fail
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+SELECT var1.a;
+ a
+------
+ 1000
+(1 row)
+
+SELECT var1;
+ var1
+------------
+ (1000,100)
+(1 row)
+
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+NOTICE: (0,100)
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+NOTICE: 0
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail again
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+-- should fail
+SELECT var1.a;
+ERROR: variable "public.var1" is of type "text", which is not a composite type
+LINE 1: SELECT var1.a;
+ ^
+SELECT var2.c;
+ERROR: could not identify column "c" in variable "public.var2"
+LINE 1: SELECT var2.c;
+ ^
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+-- should fail
+LET var1 = '1'::jsonb;
+ERROR: variable "public.var1" is of type integer, but expression is of type jsonb
+LINE 1: LET var1 = '1'::jsonb;
+ ^
+HINT: You will need to rewrite or cast the expression.
+-- should be ok
+LET var1 = '1'::jsonb::int;
+-- should fail
+LET var1.x = 10;
+ERROR: cannot assign to field "x" of session variable "public.var1" because its type integer is not a composite type
+LINE 1: LET var1.x = 10;
+ ^
+DROP VARIABLE var1;
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+-- should fail
+LET vartest.vartest = 1;
+ERROR: target "vartest.vartest" of LET command is ambiguous
+LINE 1: LET vartest.vartest = 1;
+ ^
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+ERROR: type "vartesttype" does not exist
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+ var1
+------------
+ {10.1,2.1}
+(1 row)
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+ERROR: set-returning functions are not allowed in LET
+LINE 1: LET var1[generate_series(1,3)] = 100;
+ ^
+DROP VARIABLE var1;
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+ var1
+--------------------
+ (10.2,"{0.0,0.0}")
+(1 row)
+
+LET var1.b[1] = 10.3;
+SELECT var1;
+ var1
+---------------------
+ (10.2,"{10.3,0.0}")
+(1 row)
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ count
+-------
+ 100
+(1 row)
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ QUERY PLAN
+-----------------------------------
+ Aggregate
+ -> Seq Scan on svar_test
+ Filter: ((a % 10) = zero)
+(3 rows)
+
+LET zero = (SELECT count(*) FROM svar_test);
+-- result should be 1000
+SELECT zero;
+ zero
+------
+ 1000
+(1 row)
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO on;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO off;
+DROP VIEW var1view;
+DROP VARIABLE var1;
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 100
+(1 row)
+
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 200
+(1 row)
+
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+---
+(0 rows)
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+ relname
+----------
+ pg_class
+(1 row)
+
+DROP VARIABLE var1;
+CREATE TABLE xxtab(avar int);
+INSERT INTO xxtab VALUES(333);
+CREATE TYPE xxtype AS (avar int);
+CREATE VARIABLE xxtab AS xxtype;
+INSERT INTO xxtab VALUES(10);
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+CREATE VARIABLE public.avar AS int;
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+ avar
+------
+
+
+(2 rows)
+
+DROP VARIABLE xxtab;
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+DROP VARIABLE public.avar;
+DROP TYPE xxtype;
+DROP TABLE xxtab;
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+CREATE TABLE public.svar(a int, b int);
+INSERT INTO public.svar VALUES(10, 20);
+LET public.svar = (100, 200, 300);
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT var1.* FROM vartest_foo;
+ ^
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+ a | b
+----+----
+ 10 | 20
+ 30 | 40
+(2 rows)
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT count(var1.*) FROM vartest_foo;
+ ^
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+ count
+-------
+ 2
+(1 row)
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table vartest.vartest_foo
+drop cascades to session variable vartest.var1
+CREATE TYPE ab AS (a integer, b integer);
+CREATE VARIABLE v_ab AS ab;
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+CREATE SCHEMA v_ab;
+CREATE VARIABLE v_ab.a AS integer;
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+SET search_path TO public;
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+-- should be ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+-- should be still ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+ERROR: session variable reference "xxx_am.b" is ambiguous
+LINE 1: SELECT xxx_am.b;
+ ^
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+ b
+----
+ 10
+(1 row)
+
+SELECT :"DBNAME".xxx_am.b;
+ b
+----
+ 20
+(1 row)
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+ b
+----
+ 10
+(1 row)
+
+SELECT x.b FROM xxx_am x;
+ b
+----
+ 10
+(1 row)
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+CREATE SCHEMA :"DBNAME";
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+SET search_path TO :"DBNAME";
+-- should be ambiguous
+SELECT :"DBNAME".b;
+ERROR: session variable reference "regression.b" is ambiguous
+LINE 1: SELECT "regression".b;
+ ^
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+ERROR: session variable reference "regression.regression.b" is ambiguous
+LINE 1: SELECT "regression"."regression".b;
+ ^
+CREATE TABLE :"DBNAME"(b int);
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+ b
+---
+(0 rows)
+
+DROP TABLE :"DBNAME";
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+RESET search_path;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index eeb0f94ca3c..e72360d5254 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -295,3 +295,886 @@ DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+
+-- check access rights
+CREATE ROLE regress_noowner;
+
+CREATE VARIABLE var1 AS int;
+
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+SELECT sqlfx(20);
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx(20);
+SELECT plpgsqlfx_sd(20);
+
+-- should fail
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+-- should be ok
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx_sd(20);
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+
+-- should be ok
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+
+DROP ROLE regress_noowner;
+
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- start a new session
+\c
+
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- should fail, dependency
+DROP VARIABLE var1;
+
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+
+LET var1 = 'str1';
+LET var2 = 'str2';
+
+SELECT sqlfx1(sqlfx2('Hello'));
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+
+SET plan_cache_mode TO force_generic_plan;
+
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+
+SET plan_cache_mode TO DEFAULT;
+
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP TABLE testvar;
+
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+
+-- should not crash (but is not supported yet)
+CALL p(v);
+
+DO $$ BEGIN CALL p(v); END $$;
+
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+
+-- should fail
+EXECUTE ptest(v);
+
+DEALLOCATE ptest;
+DROP VARIABLE v;
+
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+
+-- should fail
+LET var1 = pi();
+SELECT var1;
+
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+
+SET search_path TO svartest;
+
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS text;
+
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+
+-- should fail
+SELECT var1;
+
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+
+-- should fail
+LET var1 = 10;
+
+-- should fail
+LET var1 = NULL;
+
+-- note - domain defaults are not supported yet (like PLpgSQL)
+
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+
+SET search_path to public, svartest;
+
+SELECT var1;
+
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+LET var2[var1] = 0;
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+
+-- should be ok
+LET var1 = generate_series(1, 1);
+
+-- should fail
+LET var1 = generate_series(1, 2);
+LET var1 = generate_series(1, 0);
+
+DROP VARIABLE var1;
+
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+
+SELECT v1;
+SELECT v2;
+SELECT (v1).*;
+SELECT (v2).*;
+
+SELECT v1.x + v1.z;
+SELECT v2.x + v2.z;
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should fail
+SELECT v2.x;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+LET nodb.noschema.novar.nofield = 10;
+LET nodb.noschema.novar = 10;
+
+CREATE TYPE t1 AS (a int, b numeric, c text);
+
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+LET v1.b = 10.2222;
+SELECT v1;
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+
+DROP VARIABLE v1;
+DROP TYPE t1;
+
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+
+-- should fail
+DROP TABLE svar_test;
+
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+
+CREATE ROLE regress_var_test_role;
+
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+
+-- should fail
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should fail again
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+
+-- should fail
+SELECT var1.a;
+SELECT var2.c;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+
+CREATE VARIABLE var1 AS int;
+
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+
+-- should fail
+LET var1 = '1'::jsonb;
+
+-- should be ok
+LET var1 = '1'::jsonb::int;
+
+-- should fail
+LET var1.x = 10;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+
+-- should fail
+LET vartest.vartest = 1;
+
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+
+DROP VARIABLE var1;
+
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+LET var1.b[1] = 10.3;
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+LET zero = (SELECT count(*) FROM svar_test);
+
+-- result should be 1000
+SELECT zero;
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO on;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO off;
+
+DROP VIEW var1view;
+DROP VARIABLE var1;
+
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+
+DROP VARIABLE var1;
+
+CREATE TABLE xxtab(avar int);
+
+INSERT INTO xxtab VALUES(333);
+
+CREATE TYPE xxtype AS (avar int);
+
+CREATE VARIABLE xxtab AS xxtype;
+
+INSERT INTO xxtab VALUES(10);
+
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+
+-- should be ok
+SELECT avar FROM xxtab;
+
+CREATE VARIABLE public.avar AS int;
+
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+
+DROP VARIABLE xxtab;
+
+SELECT xxtab.avar FROM xxtab;
+
+DROP VARIABLE public.avar;
+
+DROP TYPE xxtype;
+
+DROP TABLE xxtab;
+
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+
+CREATE TABLE public.svar(a int, b int);
+
+INSERT INTO public.svar VALUES(10, 20);
+
+LET public.svar = (100, 200, 300);
+
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+
+CREATE TYPE ab AS (a integer, b integer);
+
+CREATE VARIABLE v_ab AS ab;
+
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+CREATE SCHEMA v_ab;
+
+CREATE VARIABLE v_ab.a AS integer;
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+
+SET search_path TO public;
+
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+
+-- should be ok
+SELECT xxx_am;
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+
+-- should be still ok
+SELECT xxx_am;
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+SELECT :"DBNAME".xxx_am.b;
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+SELECT x.b FROM xxx_am x;
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+
+CREATE SCHEMA :"DBNAME";
+
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+
+SET search_path TO :"DBNAME";
+
+-- should be ambiguous
+SELECT :"DBNAME".b;
+
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+
+CREATE TABLE :"DBNAME"(b int);
+
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+
+DROP TABLE :"DBNAME";
+
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+
+RESET search_path;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 7a3297d692d..05699203b36 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1510,6 +1510,7 @@ LargeObjectDesc
Latch
LauncherLastStartTimesEntry
LerpFunc
+LetStmt
LexDescr
LexemeEntry
LexemeHashKey
@@ -2635,6 +2636,7 @@ SerializedTransactionState
Session
SessionBackupState
SessionEndType
+SessionVariableValue
SetConstraintState
SetConstraintStateData
SetConstraintTriggerData
@@ -2830,6 +2832,9 @@ SupportRequestRows
SupportRequestSelectivity
SupportRequestSimplify
SupportRequestWFuncMonotonic
+SVariable
+SVariableData
+SVariableState
Syn
SyncOps
SyncRepConfigData
--
2.48.1
[text/x-patch] v20250301-0007-GUC-session_variables_ambiguity_warning.patch (15.1K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/8-v20250301-0007-GUC-session_variables_ambiguity_warning.patch)
download | inline diff:
From a47a731b776383996cdab4975cc0f800552c3cff Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 21 May 2024 17:55:24 +0200
Subject: [PATCH 07/21] GUC session_variables_ambiguity_warning
Inside an query the session variables can be shadowed. This behaviour is by design,
because this ensuring so new variables doesn't break existing queries. But this
behaviour can be confusing, because shadowing is quiet.
When new GUC session_variables_ambiguity_warning is on, then the warning
is displayed, when some session variable can be used, but it is not used
due shadowing. This feature should to help with investigation of unexpected
behaviour.
Note: PLpgSQL has an option that controls priority of identifier's spaces
(SQL or PLpgSQL). Default behaviour doesn't allows collisions. I believe
this default is the best. I cannot to implement similar very strict
behaviour to session variables, because one unhappy named session variable
can breaks an applications. The problems related to badly named PLpgSQL's
varible is limitted just to only one routine.
---
doc/src/sgml/config.sgml | 60 +++++++++++++++++++
doc/src/sgml/ddl.sgml | 11 ++++
src/backend/parser/parse_expr.c | 49 +++++++++++++--
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/parser/parse_expr.h | 1 +
.../src/expected/plpgsql_session_variable.out | 33 ++++++++++
.../src/sql/plpgsql_session_variable.sql | 29 +++++++++
.../regress/expected/session_variables.out | 26 ++++++++
src/test/regress/sql/session_variables.sql | 26 ++++++++
10 files changed, 241 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index e55700f35b8..b89c823f767 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11028,6 +11028,66 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-ambiguity-warning" xreflabel="session_variables_ambiguity_warning">
+ <term><varname>session_variables_ambiguity_warning</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_ambiguity_warning</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when any identifier in a query could be
+ used as both a column identifier, routine variable or a session
+ variable identifier. The default is <literal>off</literal>.
+ </para>
+ <para>
+ Session variables can be shadowed by column references in a query, this
+ is an expected behavior. Previously working queries shouldn't error out
+ by creating any session variable, so session variables are always shadowed
+ if an identifier is ambiguous. Variables should be referenced using
+ anunambiguous identifier without any possibility for a collision with
+ identifier of other database objects (column names or record fields names).
+ The warning messages emitted when enabling <varname>session_variables_ambiguity_warning</varname>
+ can help finding such identifier collision.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE a int;
+LET a = 100;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+ a
+----
+ 10
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_ambiguity_warning TO on;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a FROM foo;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a
+----
+ 10
+(1 row)
+</screen>
+ </para>
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. For testing or development environments it's recommended to
+ enable it if you use session variables.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 5e671d5be4d..96912aaa436 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5445,6 +5445,17 @@ SELECT name FROM foo;
Alice
</programlisting>
</para>
+
+ <para>
+ When a query contains identifiers or qualified identifiers that could be
+ used as both a session variable identifiers and as column identifier,
+ then the column identifier is preferred every time. Warnings can be
+ emitted when this situation happens by enabling configuration parameter <xref
+ linkend="guc-session-variables-ambiguity-warning"/>. User can explicitly
+ qualify the source object by syntax <literal>table.column</literal> or
+ <literal>schema.variable</literal>. It is strongly recommended to rename
+ shadowed variables or use qualified names always.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 4f208c7efdd..63f1732f69e 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -45,6 +45,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
+bool session_variables_ambiguity_warning = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -960,11 +961,51 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
*
* SELECT foo.a, foo.b, foo.c FROM foo;
*
- * However, that is very confusing, so we disallow it. We don't try to
- * identify a variable if we know that it would be shadowed.
- * -----
+ * However, that is very confusing, so we disallow it.
+ *
+ * When session_variables_ambiguity_warning is requested, then we
+ * need to identify a variable although we know, so this variable
+ * would be shadowed.
*/
- if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ if (node || (relname && crerr == CRERR_NO_COLUMN))
+ {
+ /*
+ * In this path we just try (if it is wanted) detect if session
+ * variable is shadowed.
+ */
+ if (session_variables_ambiguity_warning)
+ {
+ /*
+ * The AccessShareLock is created on related session variable.
+ * The lock will be kept for the whole transaction.
+ */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, true);
+
+ if (OidIsValid(varid))
+ {
+ /* this path will ending by WARNING. Unlock variable first */
+ UnlockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (node)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is shadowed",
+ NameListToString(cref->fields)),
+ errdetail("Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name."),
+ parser_errposition(pstate, cref->location)));
+ else
+ /* session variable is shadowed by RTE */
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s.%s\" is shadowed",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ errdetail("Session variables can be shadowed by tables or table's aliases with the same name."),
+ parser_errposition(pstate, cref->location)));
+ }
+ }
+ }
+ else
{
/* takes an AccessShareLock on the session variable */
varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index ad25cbb39c5..00df8951d82 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1628,6 +1628,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_ambiguity_warning", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when reference to a session variable is ambiguous."),
+ NULL
+ },
+ &session_variables_ambiguity_warning,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 5362ff80519..9f793008ab7 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -739,6 +739,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_read_only = off
#default_transaction_deferrable = off
#session_replication_role = 'origin'
+#session_variables_ambiguity_warning = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index efbaff8e710..d2209070181 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -17,6 +17,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
+extern PGDLLIMPORT bool session_variables_ambiguity_warning;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index ab779900596..a6523f7afe2 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -354,6 +354,39 @@ $$;
NOTICE: session variable is 100
NOTICE: plpgsql variable is 1000
NOTICE: variable is 1000
+-- againt with session_variables_ambiguity_warning(on)
+SET session_variables_ambiguity_warning TO on;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+WARNING: session variable "plpgsql_sv_var1" is shadowed
+LINE 1: plpgsql_sv_var1
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+QUERY: plpgsql_sv_var1
+NOTICE: variable is 1000
+SET session_variables_ambiguity_warning TO off;
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
CREATE VARIABLE plpgsql_sv_v text;
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
index a3cc264cf38..9b8e90e81fa 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -260,6 +260,35 @@ BEGIN
END;
$$;
+-- againt with session_variables_ambiguity_warning(on)
+
+SET session_variables_ambiguity_warning TO on;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+SET session_variables_ambiguity_warning TO off;
+
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 2783caa8446..7c350ad5ef9 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1524,6 +1524,9 @@ CREATE TABLE vartest_foo(a int, b int);
INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
-- should to fail
SELECT var1.* FROM vartest_foo;
ERROR: missing FROM-clause entry for table "var1"
@@ -1549,6 +1552,7 @@ SELECT count(var1.*) FROM vartest_foo var1;
2
(1 row)
+SET session_variables_ambiguity_warning TO off;
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
NOTICE: drop cascades to 2 other objects
@@ -1943,3 +1947,25 @@ SELECT var1;
(1 row)
DROP VARIABLE var1, var2;
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+CREATE VARIABLE xxtab.avar int;
+CREATE TABLE public.xxtab(avar int);
+INSERT INTO public.xxtab VALUES(1);
+LET xxtab.avar = 20;
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+WARNING: session variable "xxtab.avar" is shadowed
+LINE 1: SELECT xxtab.avar FROM public.xxtab;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ avar
+------
+ 1
+(1 row)
+
+SET session_variables_ambiguity_warning TO off;
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
+NOTICE: drop cascades to session variable xxtab.avar
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index a624ab8b67f..68be415bf26 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1079,6 +1079,10 @@ INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
+
-- should to fail
SELECT var1.* FROM vartest_foo;
@@ -1091,6 +1095,8 @@ SELECT count(var1.*) FROM vartest_foo;
-- should be ok
SELECT count(var1.*) FROM vartest_foo var1;
+SET session_variables_ambiguity_warning TO off;
+
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
@@ -1334,3 +1340,23 @@ BEGIN; DROP VARIABLE var1; ROLLBACK;
SELECT var1;
DROP VARIABLE var1, var2;
+
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+
+CREATE VARIABLE xxtab.avar int;
+
+CREATE TABLE public.xxtab(avar int);
+
+INSERT INTO public.xxtab VALUES(1);
+
+LET xxtab.avar = 20;
+
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+
+SET session_variables_ambiguity_warning TO off;
+
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
--
2.48.1
[text/x-patch] v20250301-0010-PREPARE-LET-support.patch (7.4K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/9-v20250301-0010-PREPARE-LET-support.patch)
download | inline diff:
From 6eddc423b7360d29d8efefa6c66f1f19001da43e Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 09:44:58 +0100
Subject: [PATCH 10/21] PREPARE LET support
In current code base it requires just small changes in parser. It is nice
to have to have possibility to use prepared LET statements mainly due reduction
of security risks (SQL injection), and implementation is almost cheap.
Explicit preparing is not necessity for support of LET statements in PL, because
PL uses SPI for query execution, but it is nice to have this possibility (completenees, ...)
---
doc/src/sgml/ref/prepare.sgml | 4 +-
src/backend/parser/gram.y | 3 +-
src/backend/parser/parse_cte.c | 7 ++
src/bin/psql/tab-complete.in.c | 4 +-
.../regress/expected/session_variables.out | 81 ++++++++++++++++++-
src/test/regress/sql/session_variables.sql | 57 +++++++++++++
6 files changed, 149 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/ref/prepare.sgml b/doc/src/sgml/ref/prepare.sgml
index 8ee9439f611..45d72b1d52b 100644
--- a/doc/src/sgml/ref/prepare.sgml
+++ b/doc/src/sgml/ref/prepare.sgml
@@ -116,8 +116,8 @@ PREPARE <replaceable class="parameter">name</replaceable> [ ( <replaceable class
<listitem>
<para>
Any <command>SELECT</command>, <command>INSERT</command>, <command>UPDATE</command>,
- <command>DELETE</command>, <command>MERGE</command>, or <command>VALUES</command>
- statement.
+ <command>DELETE</command>, <command>MERGE</command>, <command>VALUES</command>,
+ or <command>LET</command> statement.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 73e2ecb662c..ed656ba6364 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -12198,7 +12198,8 @@ PreparableStmt:
| InsertStmt
| UpdateStmt
| DeleteStmt
- | MergeStmt /* by default all are $$=$1 */
+ | MergeStmt
+ | LetStmt /* by default all are $$=$1 */
;
/*****************************************************************************
diff --git a/src/backend/parser/parse_cte.c b/src/backend/parser/parse_cte.c
index 79673621c9b..c62761e4eae 100644
--- a/src/backend/parser/parse_cte.c
+++ b/src/backend/parser/parse_cte.c
@@ -126,6 +126,13 @@ transformWithClause(ParseState *pstate, WithClause *withClause)
CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
ListCell *rest;
+ /* LET is allowed by parser, but not supported. Reject for now */
+ if (IsA(cte->ctequery, LetStmt))
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("LET not supported in WITH query"),
+ parser_errposition(pstate, cte->location));
+
for_each_cell(rest, withClause->ctes, lnext(withClause->ctes, lc))
{
CommonTableExpr *cte2 = (CommonTableExpr *) lfirst(rest);
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index c0f540a4b8f..681fdeb8ee2 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4689,9 +4689,9 @@ match_previous_words(int pattern_id,
else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES"))
COMPLETE_WITH("(");
-/* LET */
+/* LET, EXPLAIN LET, PREPARE LET */
/* If prev. word is LET suggest a list of variables */
- else if (Matches("LET"))
+ else if (TailMatches("LET"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
/* Complete LET <variable> with "=" */
else if (TailMatches("LET", MatchAny))
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 22cdd356641..7c63ceef2e5 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -940,9 +940,9 @@ DROP VARIABLE var1, var2;
-- the LET statement should be disallowed in CTE
CREATE VARIABLE var1 AS int;
WITH x AS (LET var1 = 100) SELECT * FROM x;
-ERROR: syntax error at or near "LET"
+ERROR: LET not supported in WITH query
LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x;
- ^
+ ^
-- should be ok
LET var1 = generate_series(1, 1);
-- should fail
@@ -2066,5 +2066,82 @@ SELECT var1;
10
(1 row)
+SET plan_cache_mode TO force_generic_plan;
+PREPARE p1 AS LET var1 = (SELECT count(*) FROM var_tab_test_table);
+LET var1 = NULL;
+EXPLAIN (COSTS OFF) EXECUTE p1;
+ QUERY PLAN
+----------------------------------------------
+ SET SESSION VARIABLE
+ Result
+ InitPlan 1
+ -> Aggregate
+ -> Seq Scan on var_tab_test_table
+(5 rows)
+
+-- should be NULL
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) EXECUTE p1;
+ QUERY PLAN
+--------------------------------------------------------------------------
+ SET SESSION VARIABLE
+ Result (actual rows=1.00 loops=1)
+ InitPlan 1
+ -> Aggregate (actual rows=1.00 loops=1)
+ -> Seq Scan on var_tab_test_table (actual rows=10.00 loops=1)
+(5 rows)
+
+-- should be 10
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SET plan_cache_mode TO DEFAULT;
+DEALLOCATE p1;
DROP VARIABLE var1;
DROP TABLE var_tab_test_table;
+CREATE VARIABLE var1 numeric;
+SET plan_cache_mode TO force_generic_plan;
+PREPARE p1(numeric) AS LET var1 = $1;
+PREPARE p2 AS SELECT var1;
+EXECUTE p1(pi() + 100);
+EXECUTE p2;
+ var1
+-----------------
+ 103.14159265359
+(1 row)
+
+-- prepared plan cache invalidation test
+DROP VARIABLE var1;
+CREATE VARIABLE var1 numeric;
+-- should be NULL
+EXECUTE p2;
+ var1
+------
+
+(1 row)
+
+DEALLOCATE p1;
+DEALLOCATE p2;
+DROP VARIABLE var1;
+SET plan_cache_mode TO force_generic_plan;
+CREATE VARIABLE var1 numeric[];
+PREPARE p1(int, numeric) AS LET var1[$1] = $2;
+LET var1 = '{}'::numeric[];
+EXECUTE p1(1, 10.2);
+EXECUTE p1(2, 10.3);
+SELECT var1;
+ var1
+-------------
+ {10.2,10.3}
+(1 row)
+
+DEALLOCATE p1;
+DROP VARIABLE var1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 3d0eb8c7ad9..18b59fc9cad 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1420,5 +1420,62 @@ EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) LET var1 = (S
-- should be 10
SELECT var1;
+SET plan_cache_mode TO force_generic_plan;
+
+PREPARE p1 AS LET var1 = (SELECT count(*) FROM var_tab_test_table);
+
+LET var1 = NULL;
+
+EXPLAIN (COSTS OFF) EXECUTE p1;
+
+-- should be NULL
+SELECT var1;
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) EXECUTE p1;
+
+-- should be 10
+SELECT var1;
+
+SET plan_cache_mode TO DEFAULT;
+
+DEALLOCATE p1;
+
DROP VARIABLE var1;
DROP TABLE var_tab_test_table;
+
+CREATE VARIABLE var1 numeric;
+
+SET plan_cache_mode TO force_generic_plan;
+
+PREPARE p1(numeric) AS LET var1 = $1;
+PREPARE p2 AS SELECT var1;
+
+EXECUTE p1(pi() + 100);
+EXECUTE p2;
+
+-- prepared plan cache invalidation test
+DROP VARIABLE var1;
+CREATE VARIABLE var1 numeric;
+
+-- should be NULL
+EXECUTE p2;
+
+DEALLOCATE p1;
+DEALLOCATE p2;
+
+DROP VARIABLE var1;
+
+SET plan_cache_mode TO force_generic_plan;
+
+CREATE VARIABLE var1 numeric[];
+
+PREPARE p1(int, numeric) AS LET var1[$1] = $2;
+
+LET var1 = '{}'::numeric[];
+EXECUTE p1(1, 10.2);
+EXECUTE p1(2, 10.3);
+
+SELECT var1;
+
+DEALLOCATE p1;
+DROP VARIABLE var1;
--
2.48.1
[text/x-patch] v20250301-0009-EXPLAIN-LET-support.patch (8.2K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/10-v20250301-0009-EXPLAIN-LET-support.patch)
download | inline diff:
From 18127f4da2f42ebd3c35435a77e4efbf32d7c046 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 21 May 2024 18:28:07 +0200
Subject: [PATCH 09/21] EXPLAIN LET support
Enhancing ExplainOnePlan is necessary to be EXPLAIN ANALYZE LET fully workable.
In this case we want to be result of query or expression written to target variable.
---
doc/src/sgml/ref/explain.sgml | 3 +-
src/backend/commands/explain.c | 28 +++++++++++--
src/backend/commands/prepare.c | 5 ++-
src/backend/parser/gram.y | 3 +-
src/include/commands/explain.h | 2 +-
.../regress/expected/session_variables.out | 40 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 21 ++++++++++
7 files changed, 94 insertions(+), 8 deletions(-)
diff --git a/doc/src/sgml/ref/explain.sgml b/doc/src/sgml/ref/explain.sgml
index 7daddf03ef0..079ccdf3cec 100644
--- a/doc/src/sgml/ref/explain.sgml
+++ b/doc/src/sgml/ref/explain.sgml
@@ -98,7 +98,8 @@ EXPLAIN [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] <rep
<command>INSERT</command>, <command>UPDATE</command>,
<command>DELETE</command>, <command>MERGE</command>,
<command>CREATE TABLE AS</command>,
- or <command>EXECUTE</command> statement
+ <command>EXECUTE</command>,
+ or <command>LET</command> statement
without letting the command affect your data, use this approach:
<programlisting>
BEGIN;
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index d8a7232cedb..b303561b8de 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -20,6 +20,7 @@
#include "commands/explain_dr.h"
#include "commands/explain_format.h"
#include "commands/prepare.h"
+#include "executor/svariableReceiver.h"
#include "foreign/fdwapi.h"
#include "jit/jit.h"
#include "libpq/pqformat.h"
@@ -493,8 +494,8 @@ standard_ExplainOneQuery(Query *query, int cursorOptions,
}
/* run it (if needed) and produce output */
- ExplainOnePlan(plan, NULL, NULL, -1, into, es, queryString, params,
- queryEnv,
+ ExplainOnePlan(plan, NULL, NULL, -1, into, query->resultVariable,
+ es, queryString, params, queryEnv,
&planduration, (es->buffers ? &bufusage : NULL),
es->memory ? &mem_counters : NULL);
}
@@ -593,6 +594,25 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
else
ExplainDummyGroup("Notify", NULL, es);
}
+ else if (IsA(utilityStmt, LetStmt))
+ {
+ LetStmt *letstmt = (LetStmt *) utilityStmt;
+ List *rewritten;
+ Query *query;
+
+ if (es->format == EXPLAIN_FORMAT_TEXT)
+ appendStringInfoString(es->str, "SET SESSION VARIABLE\n");
+ else
+ ExplainDummyGroup("Set Session Variable", NULL, es);
+
+ rewritten = QueryRewrite(castNode(Query, copyObject(letstmt->query)));
+
+ Assert(list_length(rewritten) == 1);
+ query = linitial_node(Query, rewritten);
+ ExplainOneQuery(query,
+ CURSOR_OPT_PARALLEL_OK, NULL, es,
+ pstate, params);
+ }
else
{
if (es->format == EXPLAIN_FORMAT_TEXT)
@@ -618,7 +638,7 @@ ExplainOneUtility(Node *utilityStmt, IntoClause *into, ExplainState *es,
void
ExplainOnePlan(PlannedStmt *plannedstmt, CachedPlan *cplan,
CachedPlanSource *plansource, int query_index,
- IntoClause *into, ExplainState *es,
+ IntoClause *into, Oid targetvar, ExplainState *es,
const char *queryString, ParamListInfo params,
QueryEnvironment *queryEnv, const instr_time *planduration,
const BufferUsage *bufusage,
@@ -668,6 +688,8 @@ ExplainOnePlan(PlannedStmt *plannedstmt, CachedPlan *cplan,
*/
if (into)
dest = CreateIntoRelDestReceiver(into);
+ else if (OidIsValid(targetvar))
+ dest = CreateVariableDestReceiver(targetvar);
else if (es->serialize != EXPLAIN_SERIALIZE_NONE)
dest = CreateExplainSerializeDestReceiver(es);
else
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 2d04c71a148..13d198f1625 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -668,8 +668,9 @@ ExplainExecuteQuery(ExecuteStmt *execstmt, IntoClause *into, ExplainState *es,
if (pstmt->commandType != CMD_UTILITY)
ExplainOnePlan(pstmt, cplan, entry->plansource, query_index,
- into, es, query_string, paramLI, pstate->p_queryEnv,
- &planduration, (es->buffers ? &bufusage : NULL),
+ into, InvalidOid, es, query_string, paramLI,
+ pstate->p_queryEnv, &planduration,
+ (es->buffers ? &bufusage : NULL),
es->memory ? &mem_counters : NULL);
else
ExplainOneUtility(pstmt->utilityStmt, into, es, pstate, paramLI);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 4fffb28dd4d..73e2ecb662c 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -12167,7 +12167,8 @@ ExplainableStmt:
| CreateAsStmt
| CreateMatViewStmt
| RefreshMatViewStmt
- | ExecuteStmt /* by default all are $$=$1 */
+ | ExecuteStmt
+ | LetStmt /* by default all are $$=$1 */
;
/*****************************************************************************
diff --git a/src/include/commands/explain.h b/src/include/commands/explain.h
index 64547bd9b9c..18932a9fe14 100644
--- a/src/include/commands/explain.h
+++ b/src/include/commands/explain.h
@@ -105,7 +105,7 @@ extern void ExplainOneUtility(Node *utilityStmt, IntoClause *into,
extern void ExplainOnePlan(PlannedStmt *plannedstmt, CachedPlan *cplan,
CachedPlanSource *plansource, int plan_index,
- IntoClause *into, ExplainState *es,
+ IntoClause *into, Oid targetvar, ExplainState *es,
const char *queryString,
ParamListInfo params, QueryEnvironment *queryEnv,
const instr_time *planduration,
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 9ac08a14e0b..22cdd356641 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2028,3 +2028,43 @@ DROP SCHEMA testvar;
SET session_variables_ambiguity_warning TO DEFAULT;
SET session_variables_use_fence_warning_guard TO DEFAULT;
SET search_path TO DEFAULT;
+CREATE VARIABLE var1 bigint;
+CREATE TABLE var_tab_test_table(a int);
+INSERT INTO var_tab_test_table SELECT * FROM generate_series(1,10);
+VACUUM ANALYZE var_tab_test_table;
+EXPLAIN (COSTS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+ QUERY PLAN
+----------------------------------------------
+ SET SESSION VARIABLE
+ Result
+ InitPlan 1
+ -> Aggregate
+ -> Seq Scan on var_tab_test_table
+(5 rows)
+
+-- should be NULL
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+ QUERY PLAN
+--------------------------------------------------------------------------
+ SET SESSION VARIABLE
+ Result (actual rows=1.00 loops=1)
+ InitPlan 1
+ -> Aggregate (actual rows=1.00 loops=1)
+ -> Seq Scan on var_tab_test_table (actual rows=10.00 loops=1)
+(5 rows)
+
+-- should be 10
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1;
+DROP TABLE var_tab_test_table;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index c5420183d94..3d0eb8c7ad9 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1401,3 +1401,24 @@ DROP SCHEMA testvar;
SET session_variables_ambiguity_warning TO DEFAULT;
SET session_variables_use_fence_warning_guard TO DEFAULT;
SET search_path TO DEFAULT;
+
+CREATE VARIABLE var1 bigint;
+
+CREATE TABLE var_tab_test_table(a int);
+
+INSERT INTO var_tab_test_table SELECT * FROM generate_series(1,10);
+
+VACUUM ANALYZE var_tab_test_table;
+
+EXPLAIN (COSTS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+
+-- should be NULL
+SELECT var1;
+
+EXPLAIN (COSTS OFF, TIMING OFF, ANALYZE, SUMMARY OFF, BUFFERS OFF) LET var1 = (SELECT count(*) FROM var_tab_test_table);
+
+-- should be 10
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP TABLE var_tab_test_table;
--
2.48.1
[text/x-patch] v20250301-0006-plpgsql-tests.patch (16.9K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/11-v20250301-0006-plpgsql-tests.patch)
download | inline diff:
From c34330163f7111cfb5bf308e4a7e9122a0a1b61d Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 14:06:06 +0100
Subject: [PATCH 06/21] plpgsql tests
---
src/pl/plpgsql/src/Makefile | 3 +-
.../src/expected/plpgsql_session_variable.out | 382 ++++++++++++++++++
src/pl/plpgsql/src/meson.build | 1 +
.../src/sql/plpgsql_session_variable.sql | 289 +++++++++++++
4 files changed, 674 insertions(+), 1 deletion(-)
create mode 100644 src/pl/plpgsql/src/expected/plpgsql_session_variable.out
create mode 100644 src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile
index 63cb96fae3e..bbcae27d422 100644
--- a/src/pl/plpgsql/src/Makefile
+++ b/src/pl/plpgsql/src/Makefile
@@ -35,7 +35,8 @@ REGRESS_OPTS = --dbname=$(PL_TESTDB)
REGRESS = plpgsql_array plpgsql_cache plpgsql_call plpgsql_control \
plpgsql_copy plpgsql_domain plpgsql_misc \
plpgsql_record plpgsql_simple plpgsql_transaction \
- plpgsql_trap plpgsql_trigger plpgsql_varprops
+ plpgsql_trap plpgsql_trigger plpgsql_varprops \
+ plpgsql_session_variable
# where to find gen_keywordlist.pl and subsidiary files
TOOLSDIR = $(top_srcdir)/src/tools
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
new file mode 100644
index 00000000000..ab779900596
--- /dev/null
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -0,0 +1,382 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+LET plpgsql_sv_var = pi();
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+NOTICE: value of session variable is 3.14159265358979
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+ pi_multiply_2
+------------------
+ 6.28318530717959
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var;
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+END;
+-- execute outside of a transaction
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP FUNCTION test_func();
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+SET ROLE TO regress_var_owner_role;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_reader_role;
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail
+SELECT var_read_func();
+ERROR: permission denied for session variable plpgsql_sv_var1
+CONTEXT: PL/pgSQL expression "plpgsql_sv_var1"
+PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should be ok
+SELECT var_read_func();
+NOTICE: 10
+ var_read_func
+---------------
+
+(1 row)
+
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+DROP VARIABLE plpgsql_sv_var1;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail, but not crash
+SELECT var_read_func();
+ERROR: column "plpgsql_sv_var1" does not exist
+LINE 1: plpgsql_sv_var1
+ ^
+QUERY: plpgsql_sv_var1
+CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+DROP FUNCTION var_read_func;
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+ inc_var_int
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+LET plpgsql_sv_var2 = 0.0;
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+ inc_var_num
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+NOTICE: variable is 1000
+DROP VARIABLE plpgsql_sv_var1;
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+select ffunc();
+ ffunc
+-------
+ abc
+(1 row)
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+DROP VARIABLE plpgsql_sv_v;
diff --git a/src/pl/plpgsql/src/meson.build b/src/pl/plpgsql/src/meson.build
index 33c49ac25d9..1d01d1c2629 100644
--- a/src/pl/plpgsql/src/meson.build
+++ b/src/pl/plpgsql/src/meson.build
@@ -88,6 +88,7 @@ tests += {
'plpgsql_trap',
'plpgsql_trigger',
'plpgsql_varprops',
+ 'plpgsql_session_variable',
],
},
}
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
new file mode 100644
index 00000000000..a3cc264cf38
--- /dev/null
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -0,0 +1,289 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+
+LET plpgsql_sv_var = pi();
+
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+
+DROP VARIABLE plpgsql_sv_var;
+
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+END;
+
+-- execute outside of a transaction
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+SELECT test_func();
+
+DROP FUNCTION test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+SET ROLE TO regress_var_owner_role;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_reader_role;
+
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should be ok
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail, but not crash
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+DROP FUNCTION var_read_func;
+
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+
+LET plpgsql_sv_var2 = 0.0;
+
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+
+select ffunc();
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+
+DROP VARIABLE plpgsql_sv_v;
--
2.48.1
[text/x-patch] v20250301-0008-variable-fence-syntax-support-and-variable-fence-usa.patch (19.5K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/12-v20250301-0008-variable-fence-syntax-support-and-variable-fence-usa.patch)
download | inline diff:
From a374507f2a1ee6a63348e2e610b7d21494576230 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 19 Nov 2024 08:14:53 +0100
Subject: [PATCH 08/21] variable fence syntax support and variable fence usage
guard support
this patch introduces a concept of variable fence - syntax for variable
reference `VARIABLE(varname)` that is not in collision with column reference.
When variable fence usage guard warning is active, then usage variable
without variable fence in the case, where there can be column references,
the the warning is raised.
initial implementation of variable fence
---
doc/src/sgml/config.sgml | 65 ++++++++++++++++
doc/src/sgml/ddl.sgml | 15 ++++
src/backend/nodes/nodeFuncs.c | 6 ++
src/backend/parser/gram.y | 28 ++++++-
src/backend/parser/parse_expr.c | 74 ++++++++++++++++++-
src/backend/parser/parse_target.c | 7 ++
src/backend/utils/adt/ruleutils.c | 12 ++-
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/nodes/parsenodes.h | 10 +++
src/include/nodes/primnodes.h | 2 +
src/include/parser/parse_expr.h | 1 +
.../regress/expected/session_variables.out | 59 +++++++++++++++
src/test/regress/sql/session_variables.sql | 41 ++++++++++
14 files changed, 323 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index b89c823f767..241b6855bf6 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11088,6 +11088,71 @@ DETAIL: Session variables can be shadowed by columns, routine's variables and r
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-use-fence-warning-guard" xreflabel="session_variables_use_fence_warning_guard">
+ <term><varname>session_variables_use_fence_warning_guard</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_use_fence_warning_guard</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when a session variable identifier is used
+ inside a query without variable fence. The default is <literal>off</literal>.
+ The warning is raised only when variable is used in places, where an
+ collisions with column names is possible.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE b int;
+LET b = 100;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_use_fence_warning_guard TO on;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "b" is not used inside variable fence
+LINE 1: SELECT a, b FROM foo;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SELECT a, VARIABLE(b) FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+ </para>
+
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. Unless another collision resolution technique is used
+ (dedicated schema or using prefixes like <literal>_</literal>),
+ the use of variable fence syntax is strongly recommended, and this
+ warning should be enabled.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 96912aaa436..4e8e7c6a42a 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5456,6 +5456,21 @@ SELECT name FROM foo;
<literal>schema.variable</literal>. It is strongly recommended to rename
shadowed variables or use qualified names always.
</para>
+
+ <para><firstterm>Variable fence</firstterm> is special syntax for session
+ variable identifier. Only name or qualified name can be used inside the
+ variable fence, and this name is used as only session variable identifier.
+<programlisting>
+SELECT VARIABLE(current_user_id);
+</programlisting>
+ </para>
+
+ <para>
+ When there is a risk of possible collisions between variable identifiers
+ and column names, then using variable fence syntax can be recommended.
+ Usage session variable without variable fence can be detected by
+ warning <xref linkend="guc-session-variables-use-fence-warning-guard"/>.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d8fc3d9fa69..575365eefcd 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1673,6 +1673,9 @@ exprLocation(const Node *expr)
case T_ParamRef:
loc = ((const ParamRef *) expr)->location;
break;
+ case T_VariableFence:
+ loc = ((const VariableFence *) expr)->location;
+ break;
case T_A_Const:
loc = ((const A_Const *) expr)->location;
break;
@@ -4715,6 +4718,9 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_VariableFence:
+ /* we assume the fields contain nothing interesting */
+ break;
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 2cb5c57fb61..4fffb28dd4d 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -525,7 +525,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <node> def_arg columnElem where_clause where_or_current_clause
a_expr b_expr c_expr AexprConst indirection_el opt_slice_bound
columnref in_expr having_clause func_table xmltable array_expr
- OptWhereClause operator_def_arg
+ OptWhereClause operator_def_arg variable_fence
%type <list> opt_column_and_period_list
%type <list> rowsfrom_item rowsfrom_list opt_col_def_list
%type <boolean> opt_ordinality opt_without_overlaps
@@ -882,7 +882,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
*/
%nonassoc UNBOUNDED NESTED /* ideally would have same precedence as IDENT */
%nonassoc IDENT PARTITION RANGE ROWS GROUPS PRECEDING FOLLOWING CUBE ROLLUP
- SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH
+ SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH VARIABLE
%left Op OPERATOR /* multi-character ops and user-defined operators */
%left '+' '-'
%left '*' '/' '%'
@@ -15668,6 +15668,19 @@ c_expr: columnref { $$ = $1; }
else
$$ = $2;
}
+ | variable_fence opt_indirection
+ {
+ if ($2)
+ {
+ A_Indirection *n = makeNode(A_Indirection);
+
+ n->arg = (Node *) $1;
+ n->indirection = check_indirection($2, yyscanner);
+ $$ = (Node *) n;
+ }
+ else
+ $$ = $1;
+ }
| case_expr
{ $$ = $1; }
| func_expr
@@ -17054,6 +17067,17 @@ case_arg: a_expr { $$ = $1; }
| /*EMPTY*/ { $$ = NULL; }
;
+variable_fence:
+ VARIABLE '(' any_name ')'
+ {
+ VariableFence *vf = makeNode(VariableFence);
+
+ vf->varname = $3;
+ vf->location = @3;
+ $$ = (Node *) vf;
+ }
+ ;
+
columnref: ColId
{
$$ = makeColumnRef($1, NIL, @1, yyscanner);
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 63f1732f69e..dd03b1f14db 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -46,6 +46,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
bool session_variables_ambiguity_warning = false;
+bool session_variables_use_fence_warning_guard = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -81,6 +82,7 @@ static Node *transformWholeRowRef(ParseState *pstate,
static Node *transformIndirection(ParseState *pstate, A_Indirection *ind);
static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
static Node *transformCollateClause(ParseState *pstate, CollateClause *c);
+static Node *transformVariableFence(ParseState *pstate, VariableFence *vf);
static Node *transformJsonObjectConstructor(ParseState *pstate,
JsonObjectConstructor *ctor);
static Node *transformJsonArrayConstructor(ParseState *pstate,
@@ -112,7 +114,7 @@ static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
static Node *makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location);
+ char *attrname, bool fenced, int location);
/*
@@ -377,6 +379,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
result = transformJsonFuncExpr(pstate, (JsonFuncExpr *) expr);
break;
+ case T_VariableFence:
+ result = transformVariableFence(pstate, (VariableFence *) expr);
+ break;
+
default:
/* should not reach here */
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
@@ -1028,7 +1034,20 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
node = makeParamSessionVariable(pstate,
varid, typid, typmod, collid,
- attrname, cref->location);
+ attrname, false, cref->location);
+
+ /*
+ * The variable is not inside variable's fence, so raise warning
+ * when variable fence guard is active and the query has FROM
+ * clause.
+ */
+ if (session_variables_use_fence_warning_guard && pstate->p_rtable)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is not used inside variable fence",
+ NameListToString(cref->fields)),
+ errdetail("The collision of session variable' names and column names is possible."),
+ parser_errposition(pstate, cref->location)));
}
}
}
@@ -1071,7 +1090,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
static Node *
makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location)
+ char *attrname, bool fenced, int location)
{
Param *param;
@@ -1079,6 +1098,7 @@ makeParamSessionVariable(ParseState *pstate,
param->paramkind = PARAM_VARIABLE;
param->paramvarid = varid;
+ param->paramvarfenced = fenced;
param->paramtype = typid;
param->paramtypmod = typmod;
param->paramcollid = collid;
@@ -1157,6 +1177,54 @@ transformParamRef(ParseState *pstate, ParamRef *pref)
return result;
}
+static Node *
+transformVariableFence(ParseState *pstate, VariableFence *vf)
+{
+ Node *result;
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* VariableFence can be used only in context when variables are supported */
+ if (!expr_kind_allows_session_variables(pstate->p_expr_kind))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable reference is not supported here"),
+ parser_errposition(pstate, vf->location)));
+
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(vf->varname, &attrname, ¬_unique, false);
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ result = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, true, vf->location);
+ }
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ return result;
+}
+
/* Test whether an a_expr is a plain NULL constant or not */
static bool
exprIsNullConstant(Node *arg)
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d5..cf01bff65a9 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -2034,6 +2034,13 @@ FigureColnameInternal(Node *node, char **name)
(int) ((JsonFuncExpr *) node)->op);
}
break;
+ case T_VariableFence:
+ {
+ /* return last field name */
+ *name = strVal(llast(((VariableFence *) node)->varname));
+ return 2;
+ }
+ break;
default:
break;
}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index de503d38f19..0adf9255015 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8682,8 +8682,16 @@ get_parameter(Param *param, deparse_context *context)
/* translate paramvarid to session variable name */
if (param->paramkind == PARAM_VARIABLE)
{
- appendStringInfo(context->buf, "%s",
- generate_session_variable_name(param->paramvarid));
+ if (param->paramvarfenced)
+ {
+ appendStringInfo(context->buf, "VARIABLE(%s)",
+ generate_session_variable_name(param->paramvarid));
+ }
+ else
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ }
return;
}
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 00df8951d82..b8cfdc662e0 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1637,6 +1637,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_use_fence_warning_guard", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when variable is not used inside variable fence."),
+ NULL
+ },
+ &session_variables_use_fence_warning_guard,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 9f793008ab7..deea15246d7 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -740,6 +740,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_deferrable = off
#session_replication_role = 'origin'
#session_variables_ambiguity_warning = off
+#session_variables_use_fence_warning_guard = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 04c6126f22b..6327dba3b71 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -321,6 +321,16 @@ typedef struct ParamRef
ParseLoc location; /* token location, or -1 if unknown */
} ParamRef;
+/*
+ * VariableFence - ensure so fields will be interpretted as a variable
+ */
+typedef struct VariableFence
+{
+ NodeTag type;
+ List *varname; /* variable name (String nodes) */
+ ParseLoc location; /* token location, or -1 if unknown */
+} VariableFence;
+
/*
* A_Expr - infix, prefix, and postfix expressions
*/
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 24033045746..be63a8d0645 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -411,6 +411,8 @@ typedef struct Param
* param is used just for execution of UPDATE operation.
*/
bool parambasenode;
+ /* true when variable is used inside an fence */
+ bool paramvarfenced;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index d2209070181..5bde43758d1 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -18,6 +18,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
extern PGDLLIMPORT bool session_variables_ambiguity_warning;
+extern PGDLLIMPORT bool session_variables_use_fence_warning_guard;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7c350ad5ef9..9ac08a14e0b 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1969,3 +1969,62 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
NOTICE: drop cascades to session variable xxtab.avar
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+CREATE SCHEMA testvar;
+SET search_path TO 'testvar';
+CREATE VARIABLE a AS int;
+LET a = 10;
+CREATE TABLE test_table(a int, b int);
+INSERT INTO test_table VALUES(20, 20);
+-- no warning
+SELECT a;
+ a
+----
+ 10
+(1 row)
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a | b
+----+----
+ 20 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a) FROM test_table;
+ a
+----
+ 10
+(1 row)
+
+ALTER TABLE test_table DROP COLUMN a;
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is not used inside variable fence
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+DROP SCHEMA testvar;
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 68be415bf26..c5420183d94 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1360,3 +1360,44 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
+
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+
+CREATE SCHEMA testvar;
+
+SET search_path TO 'testvar';
+
+CREATE VARIABLE a AS int;
+LET a = 10;
+
+CREATE TABLE test_table(a int, b int);
+
+INSERT INTO test_table VALUES(20, 20);
+
+-- no warning
+SELECT a;
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a) FROM test_table;
+
+ALTER TABLE test_table DROP COLUMN a;
+
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+
+DROP SCHEMA testvar;
+
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
--
2.48.1
[text/x-patch] v20250301-0013-Implementation-of-DEFAULT-clause-default-expressions.patch (32.1K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/13-v20250301-0013-Implementation-of-DEFAULT-clause-default-expressions.patch)
download | inline diff:
From e28dc73b161a2feb1a27015a99c758bbfd54fe41 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:03:53 +0100
Subject: [PATCH 13/21] Implementation of DEFAULT clause - default expressions
for session variables
When the evaluation of default expression fails, we remove related entry from sessionvars
hash table. Then sessionvars can contain only sucessfully initialized values. Then we don't
need special flag for badly initialized session variables.
---
doc/src/sgml/catalogs.sgml | 8 ++
doc/src/sgml/ddl.sgml | 16 ++--
doc/src/sgml/ref/create_variable.sgml | 21 +++--
doc/src/sgml/ref/discard.sgml | 3 +-
src/backend/catalog/pg_variable.c | 27 ++++++
src/backend/commands/session_variable.c | 87 ++++++++++++++++++-
src/backend/parser/gram.y | 15 +++-
src/backend/parser/parse_agg.c | 2 +
src/backend/parser/parse_expr.c | 4 +
src/backend/parser/parse_func.c | 1 +
src/bin/pg_dump/pg_dump.c | 14 +++
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_dump/t/002_pg_dump.pl | 36 ++++++++
src/bin/psql/describe.c | 4 +-
src/include/catalog/pg_variable.h | 3 +
src/include/nodes/parsenodes.h | 1 +
src/include/parser/parse_node.h | 1 +
src/test/regress/expected/psql.out | 36 ++++----
.../regress/expected/session_variables.out | 63 ++++++++++++++
src/test/regress/sql/session_variables.sql | 48 ++++++++++
20 files changed, 350 insertions(+), 41 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 687d1c8733a..27bdaf62668 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9899,6 +9899,14 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vardefexpr</structfield> <type>pg_node_tree</type>
+ </para>
+ <para>
+ The internal representation of the variable default value
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 3e2cb3c46eb..4c6988540e8 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5407,14 +5407,14 @@ SELECT current_user_id;
<para>
The value of a session variable is local to the current session. Retrieving
- a variable's value returns a <literal>NULL</literal>, unless its value has
- been set to something else in the current session using the
- <command>LET</command> command. Session variables are not transactional:
- any changes made to the value of a session variable in a transaction won't
- be undone if the transaction is rolled back (just like variables in
- procedural languages). Session variables themselves can be persistent
- or temporary, but their values are neither persistent nor shared (like the
- content of temporary tables).
+ a variable's value returns a <literal>NULL</literal> or a default value,
+ unless its value has been set to something else in the current session
+ using the <command>LET</command> command. Session variables are not
+ transactional: any changes made to the value of a session variable in
+ a transaction won't be undone if the transaction is rolled back (just like
+ variables in procedural languages). Session variables themselves can be
+ persistent or temporary, but their values are neither persistent nor shared
+ (like the content of temporary tables).
</para>
<para>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index c89a65fb55f..e4d8851ccb8 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -27,7 +27,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
- [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
+ [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -41,10 +41,10 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
<para>
The value of a session variable is local to the current session. Retrieving
- a session variable's value returns NULL, unless its value is set to
- something else in the current session with a <command>LET</command> command.
- The content of a session variable is not transactional. This is the same as
- regular variables in procedural languages.
+ a session variable's value returns NULL or a default value, unless its value
+ is set to something else in the current session with a <command>LET</command>
+ command. The content of a session variable is not transactional. This is the
+ same as regular variables in procedural languages.
</para>
<para>
@@ -105,6 +105,17 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-default">
+ <term><literal>DEFAULT <replaceable>default_expr</replaceable></literal></term>
+ <listitem>
+ <para>
+ The <literal>DEFAULT</literal> clause can be used to assign a default
+ value to a session variable. This expression is evaluated when the session
+ variable is first accessed for reading and had not yet been assigned a value.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createvariable-on-commit-drop">
<term><literal>ON COMMIT DROP</literal></term>
<listitem>
diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
index 61b967f9c9b..6b0cb95034f 100644
--- a/doc/src/sgml/ref/discard.sgml
+++ b/doc/src/sgml/ref/discard.sgml
@@ -71,7 +71,8 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES }
<listitem>
<para>
Resets the value of all session variables. If a variable
- is later reused, it is re-initialized to <literal>NULL</literal>.
+ is later reused, it is re-initialized to either
+ <literal>NULL</literal> or its default value.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 00c90ea6fd8..8fba4cc493b 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -24,6 +24,9 @@
#include "catalog/pg_variable.h"
#include "commands/session_variable.h"
#include "miscadmin.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_collate.h"
+#include "parser/parse_expr.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
@@ -37,6 +40,7 @@ static ObjectAddress create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ Node *varDefexpr,
VariableXactEndAction varXactEndAction);
@@ -51,6 +55,7 @@ create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ Node *varDefexpr,
VariableXactEndAction varXactEndAction)
{
Acl *varacl;
@@ -114,6 +119,11 @@ create_variable(const char *varName,
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
+ if (varDefexpr)
+ values[Anum_pg_variable_vardefexpr - 1] = CStringGetTextDatum(nodeToString(varDefexpr));
+ else
+ nulls[Anum_pg_variable_vardefexpr - 1] = true;
+
varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
varNamespace);
if (varacl != NULL)
@@ -150,6 +160,11 @@ create_variable(const char *varName,
record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
free_object_addresses(addrs);
+ /* dependency on default expr */
+ if (varDefexpr)
+ recordDependencyOnExpr(&myself, (Node *) varDefexpr,
+ NIL, DEPENDENCY_NORMAL);
+
/* dependency on owner */
recordDependencyOnOwner(VariableRelationId, varid, varOwner);
@@ -185,6 +200,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
Oid collation;
Oid typcollation;
ObjectAddress variable;
+ Node *cooked_default = NULL;
/* check consistency of arguments */
if (stmt->XactEndAction == VARIABLE_XACTEND_DROP
@@ -226,6 +242,16 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
format_type_be(typid)),
parser_errposition(pstate, stmt->collClause->location)));
+ if (stmt->defexpr)
+ {
+ cooked_default = transformExpr(pstate, stmt->defexpr,
+ EXPR_KIND_VARIABLE_DEFAULT);
+
+ cooked_default = coerce_to_specific_type(pstate,
+ cooked_default, typid, "DEFAULT");
+ assign_expr_collations(pstate, cooked_default);
+ }
+
variable = create_variable(stmt->variable->relname,
namespaceid,
typid,
@@ -233,6 +259,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
varowner,
collation,
stmt->if_not_exists,
+ cooked_default,
stmt->XactEndAction);
elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index f12c20c849f..c12f20eaba7 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -22,6 +22,7 @@
#include "executor/svariableReceiver.h"
#include "funcapi.h"
#include "miscadmin.h"
+#include "optimizer/optimizer.h"
#include "rewrite/rewriteHandler.h"
#include "storage/lmgr.h"
#include "storage/proc.h"
@@ -510,11 +511,68 @@ AtEOSubXact_SessionVariables(bool isCommit,
}
}
+/*
+ * evaluate an expression
+ */
+static void
+eval_assign_defexpr(SVariable svar, HeapTuple tup)
+{
+ Datum defexpr_value;
+ bool isnull;
+
+ Assert(svar);
+ Assert(svar->is_valid);
+ Assert(HeapTupleIsValid(tup));
+
+ defexpr_value = SysCacheGetAttr(VARIABLEOID,
+ tup,
+ Anum_pg_variable_vardefexpr,
+ &isnull);
+
+ if (!isnull)
+ {
+ EState *estate;
+ ExprState *defexprs;
+ Expr *defexpr;
+ char *defexpr_str;
+ Datum value;
+ MemoryContext oldcxt;
+
+ estate = CreateExecutorState();
+
+ defexpr_str = TextDatumGetCString(defexpr_value);
+ defexpr = (Expr *) stringToNode(defexpr_str);
+
+ oldcxt = MemoryContextSwitchTo(estate->es_query_cxt);
+
+ defexpr = expression_planner((Expr *) defexpr);
+ defexprs = ExecInitExpr(defexpr, NULL);
+
+ value = ExecEvalExprSwitchContext(defexprs,
+ GetPerTupleExprContext(estate),
+ &isnull);
+
+ MemoryContextSwitchTo(oldcxt);
+
+ if (!isnull)
+ {
+ oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
+
+ svar->value = datumCopy(value, svar->typbyval, svar->typlen);
+ svar->isnull = false;
+
+ MemoryContextSwitchTo(oldcxt);
+ }
+
+ FreeExecutorState(estate);
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
static void
-setup_session_variable(SVariable svar, Oid varid)
+setup_session_variable(SVariable svar, Oid varid, bool is_write)
{
HeapTuple tup;
Form_pg_variable varform;
@@ -564,6 +622,9 @@ setup_session_variable(SVariable svar, Oid varid)
svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
ObjectIdGetDatum(varid));
+ if (!is_write)
+ eval_assign_defexpr(svar, tup);
+
ReleaseSysCache(tup);
}
@@ -593,7 +654,7 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
*/
if (!svar->is_valid)
{
- setup_session_variable(&locsvar, svar->varid);
+ setup_session_variable(&locsvar, svar->varid, false);
_svar = &locsvar;
}
else
@@ -726,7 +787,25 @@ get_session_variable(Oid varid)
*/
if (!svar->is_valid)
{
- setup_session_variable(svar, varid);
+ /* in this case we want to use defexp if it is defined */
+ PG_TRY();
+ {
+ /*
+ * In this case, the setup can execute default expression. When
+ * the execution of default expression fails, then we need to
+ * remove entry from session vars.
+ */
+ setup_session_variable(svar, varid, false);
+ }
+ PG_CATCH();
+ {
+ /* this entry cannot be valid, remove from sessionvars */
+ hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
+
+ /* propagate the error */
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)",
get_namespace_name(get_session_variable_namespace(varid)),
@@ -790,7 +869,7 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
if (!found)
{
- setup_session_variable(svar, varid);
+ setup_session_variable(svar, varid, true);
elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)",
get_namespace_name(get_session_variable_namespace(svar->varid)),
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index fb8cc863748..6ee6ed43b8c 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -645,6 +645,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <partboundspec> PartitionBoundSpec
%type <list> hash_partbound
%type <defelt> hash_partbound_elem
+%type <node> OptSessionVarDefExpr
%type <node> json_format_clause
json_format_clause_opt
@@ -5264,30 +5265,36 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause XactEndActionOption
+ CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
$4->relpersistence = $2;
n->variable = $4;
n->typeName = $6;
n->collClause = (CollateClause *) $7;
- n->XactEndAction = $8;
+ n->defexpr = $8;
+ n->XactEndAction = $9;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause XactEndActionOption
+ | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
$7->relpersistence = $2;
n->variable = $7;
n->typeName = $9;
n->collClause = (CollateClause *) $10;
- n->XactEndAction = $11;
+ n->defexpr = $11;
+ n->XactEndAction = $12;
n->if_not_exists = true;
$$ = (Node *) n;
}
;
+OptSessionVarDefExpr: DEFAULT b_expr { $$ = $2; }
+ | /* EMPTY */ { $$ = NULL; }
+ ;
+
/*
* Temporary session variables can be dropped on successful
* transaction end like tables.
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 4737b04d171..54b765c8eb5 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -488,6 +488,7 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
if (isAgg)
err = _("aggregate functions are not allowed in DEFAULT expressions");
@@ -937,6 +938,7 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
err = _("window functions are not allowed in DEFAULT expressions");
break;
case EXPR_KIND_INDEX_EXPRESSION:
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index dd03b1f14db..158a67be523 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -588,6 +588,7 @@ expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
case EXPR_KIND_JOIN_USING:
case EXPR_KIND_CYCLE_MARK:
case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_VARIABLE_DEFAULT:
result = false;
break;
}
@@ -673,6 +674,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
case EXPR_KIND_CYCLE_MARK:
case EXPR_KIND_ASSIGN_TARGET:
case EXPR_KIND_LET_TARGET:
+ case EXPR_KIND_VARIABLE_DEFAULT:
/* okay */
break;
@@ -2146,6 +2148,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
err = _("cannot use subquery in DEFAULT expression");
break;
case EXPR_KIND_INDEX_EXPRESSION:
@@ -3508,6 +3511,7 @@ ParseExprKindName(ParseExprKind exprKind)
return "CHECK";
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
return "DEFAULT";
case EXPR_KIND_INDEX_EXPRESSION:
return "index expression";
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index dc25f6dcd0e..d9f15c2618f 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2620,6 +2620,7 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location)
break;
case EXPR_KIND_COLUMN_DEFAULT:
case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_VARIABLE_DEFAULT:
err = _("set-returning functions are not allowed in DEFAULT expressions");
break;
case EXPR_KIND_INDEX_EXPRESSION:
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 8da25544ef2..acd370c3f20 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5471,6 +5471,7 @@ getVariables(Archive *fout)
int i_varnamespace;
int i_vartype;
int i_vartypname;
+ int i_vardefexpr;
int i_varxactendaction;
int i_varowner;
int i_varcollation;
@@ -5494,6 +5495,7 @@ getVariables(Archive *fout)
" THEN v.varcollation\n"
" ELSE 0\n"
" END AS varcollation,\n"
+ " pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n"
" v.varowner, v.varacl,\n"
" acldefault('V', v.varowner) AS acldefault\n"
"FROM pg_catalog.pg_variable v\n"
@@ -5510,6 +5512,7 @@ getVariables(Archive *fout)
i_varnamespace = PQfnumber(res, "varnamespace");
i_vartype = PQfnumber(res, "vartype");
i_vartypname = PQfnumber(res, "vartypname");
+ i_vardefexpr = PQfnumber(res, "vardefexpr");
i_varxactendaction = PQfnumber(res, "varxactendaction");
i_varcollation = PQfnumber(res, "varcollation");
@@ -5545,6 +5548,11 @@ getVariables(Archive *fout)
varinfo[i].dacl.initprivs = NULL;
varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner));
+ if (PQgetisnull(res, i, i_vardefexpr))
+ varinfo[i].vardefexpr = NULL;
+ else
+ varinfo[i].vardefexpr = pg_strdup(PQgetvalue(res, i, i_vardefexpr));
+
/* do not try to dump ACL if no ACL exists */
if (!PQgetisnull(res, i, i_varacl))
varinfo[i].dobj.components |= DUMP_COMPONENT_ACL;
@@ -5577,6 +5585,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
PQExpBuffer query;
char *qualvarname;
const char *vartypname;
+ const char *vardefexpr;
const char *varxactendaction;
Oid varcollation;
@@ -5589,6 +5598,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
vartypname = varinfo->vartypname;
+ vardefexpr = varinfo->vardefexpr;
varxactendaction = varinfo->varxactendaction;
varcollation = varinfo->varcollation;
@@ -5608,6 +5618,10 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
fmtQualifiedDumpable(coll));
}
+ if (vardefexpr)
+ appendPQExpBuffer(query, " DEFAULT %s",
+ vardefexpr);
+
if (strcmp(varxactendaction, "r") == 0)
appendPQExpBuffer(query, " ON TRANSACTION END RESET");
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index c8bb78d164c..b94c03b647d 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -740,6 +740,7 @@ typedef struct _VariableInfo
DumpableAcl dacl;
Oid vartype;
char *vartypname;
+ char *vardefexpr;
char *varxactendaction;
Oid varcollation;
const char *rolname; /* name of owner, or empty string */
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 7fe4cc8f223..33656196d92 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4129,6 +4129,42 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable DEFAULT' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable3 AS integer DEFAULT 10;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable3 AS integer DEFAULT 10;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
+ 'CREATE VARIABLE test_variable DEFAULT ON TRANSACTION END RESET' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable4 AS integer DEFAULT 10 ON TRANSACTION END RESET',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable4 AS integer DEFAULT 10 ON TRANSACTION END RESET;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a84222b7762..7780fc232ff 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5352,6 +5352,7 @@ listVariables(const char *pattern, bool verbose)
" (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
" WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
+ " pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
" WHEN 'r' THEN 'ON TRANSACTION END RESET'\n"
@@ -5361,6 +5362,7 @@ listVariables(const char *pattern, bool verbose)
gettext_noop("Type"),
gettext_noop("Collation"),
gettext_noop("Owner"),
+ gettext_noop("Default"),
gettext_noop("Transactional end action"));
if (verbose)
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 008f2ee7c17..09dd44a44e1 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -68,6 +68,9 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* access permissions */
aclitem varacl[1] BKI_DEFAULT(_null_);
+ /* list of expression trees for variable default (NULL if none) */
+ pg_node_tree vardefexpr BKI_DEFAULT(_null_);
+
#endif
} FormData_pg_variable;
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 2e4d9ab5f47..67ef92685fd 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3546,6 +3546,7 @@ typedef struct CreateSessionVarStmt
TypeName *typeName; /* the type of variable */
CollateClause *collClause;
bool if_not_exists; /* do nothing if it already exists */
+ Node *defexpr; /* default expression */
char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 0b7b69a4159..6b55cc8308b 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -84,6 +84,7 @@ typedef enum ParseExprKind
EXPR_KIND_CYCLE_MARK, /* cycle mark value */
EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */
EXPR_KIND_LET_TARGET, /* LET target */
+ EXPR_KIND_VARIABLE_DEFAULT, /* default value for session variable */
} ParseExprKind;
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index fd3f1243fc3..c5380d1d855 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6026,20 +6026,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+--------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+---------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+--------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+---------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6507,9 +6507,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action
---------+------+------+-----------+-------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action
+--------+------+------+-----------+-------+---------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6682,9 +6682,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action
---------+------+------+-----------+-------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action
+--------+------+------+-----------+-------+---------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6821,9 +6821,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Transactional end action
---------+------+------+-----------+-------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Default | Transactional end action
+--------+------+------+-----------+-------+---------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index a593d05c2ca..84c681ff716 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2299,3 +2299,66 @@ SELECT var1 IS NULL;
(1 row)
DROP VARIABLE var1;
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE NOTICE 'vartest_fx executed';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+CREATE VARIABLE var1 AS int DEFAULT vartest_fx();
+-- vartest_fx should be protected by dep, should fail
+DROP FUNCTION vartest_fx();
+ERROR: cannot drop function vartest_fx() because other objects depend on it
+DETAIL: session variable var1 depends on function vartest_fx()
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+SELECT var1;
+NOTICE: vartest_fx executed
+ var1
+------
+ 0
+(1 row)
+
+-- the defexpr should be evaluated only once
+SELECT var1;
+ var1
+------
+ 0
+(1 row)
+
+DISCARD VARIABLES;
+-- in this case, the defexpr should not be evaluated
+LET var1 = 100;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DISCARD VARIABLES;
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE EXCEPTION 'vartest_fx is executing';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+-- should to fail, but not to crash
+SELECT var1;
+ERROR: vartest_fx is executing
+CONTEXT: PL/pgSQL function vartest_fx() line 3 at RAISE
+-- again
+SELECT var1;
+ERROR: vartest_fx is executing
+CONTEXT: PL/pgSQL function vartest_fx() line 3 at RAISE
+-- but we can write
+LET var1 = 100;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index d6e7c21bf16..2c7388639d9 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1565,3 +1565,51 @@ ROLLBACK;
SELECT var1 IS NULL;
DROP VARIABLE var1;
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE NOTICE 'vartest_fx executed';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE VARIABLE var1 AS int DEFAULT vartest_fx();
+
+-- vartest_fx should be protected by dep, should fail
+DROP FUNCTION vartest_fx();
+
+-- should be ok
+SELECT var1;
+
+-- the defexpr should be evaluated only once
+SELECT var1;
+
+DISCARD VARIABLES;
+
+-- in this case, the defexpr should not be evaluated
+LET var1 = 100;
+SELECT var1;
+
+DISCARD VARIABLES;
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RAISE EXCEPTION 'vartest_fx is executing';
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+
+-- should to fail, but not to crash
+SELECT var1;
+
+-- again
+SELECT var1;
+
+-- but we can write
+LET var1 = 100;
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
--
2.48.1
[text/x-patch] v20250301-0012-Implementation-ON-TRANSACTION-END-RESET-clause.patch (14.6K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/14-v20250301-0012-Implementation-ON-TRANSACTION-END-RESET-clause.patch)
download | inline diff:
From f3089eaad33f36913fb29bcef77b247433b22bc1 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:02:13 +0100
Subject: [PATCH 12/21] Implementation ON TRANSACTION END RESET clause
This is simple patch - just add special flag to session variable memory entry.
The entries with active this flag are removed from sessionvars hash table
at transaction end. The "TRANSACTION END" is synonyms for "COMMIT ROLLBACK"
but the "TRANSACTION END" is more illustrative and less confusing then "COMMIT ROLLBACK".
---
doc/src/sgml/catalogs.sgml | 3 +-
doc/src/sgml/ref/create_variable.sgml | 13 ++++-
src/backend/commands/session_variable.c | 51 +++++++++++++++++++
src/backend/parser/gram.y | 1 +
src/bin/pg_dump/pg_dump.c | 11 ++++
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_dump/t/002_pg_dump.pl | 18 +++++++
src/bin/psql/describe.c | 1 +
src/include/catalog/pg_variable.h | 1 +
.../isolation/expected/session-variable.out | 4 +-
.../isolation/specs/session-variable.spec | 4 +-
.../regress/expected/session_variables.out | 34 +++++++++++++
src/test/regress/sql/session_variables.sql | 20 ++++++++
13 files changed, 158 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 09b635c234a..687d1c8733a 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9871,7 +9871,8 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para>
<para>
Action performed at end of transaction:
- <literal>n</literal> = no action, <literal>d</literal> = drop the variable.
+ <literal>n</literal> = no action, <literal>d</literal> = drop the variable,
+ <literal>r</literal> = reset the variable to its default value.
</para></entry>
</row>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index a88e0175bea..c89a65fb55f 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -27,7 +27,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
- [ ON COMMIT DROP ]
+ [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -117,6 +117,17 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-on-transaction-end-reset">
+ <term><literal>ON TRANSACTION END RESET</literal></term>
+ <listitem>
+ <para>
+ The <literal>ON TRANSACTION END RESET</literal> clause causes the session
+ variable to be reset to its default value when the transaction is committed
+ or rolled back.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</refsect1>
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index dc51a778bf5..f12c20c849f 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -83,6 +83,8 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ bool reset_at_eox;
+
/*
* Top level local transaction id of the last transaction that dropped the
* variable, if any. We need this information to avoid freeing memory for
@@ -110,6 +112,12 @@ static MemoryContext SVariableMemoryContext = NULL;
/* becomes true when we receive a sinval message */
static bool needs_validation = false;
+/*
+ * true, when some used session variable has ON COMMIT DROP
+ * or ON TRANSACTION END RESET clauses
+ */
+static bool has_session_variables_with_reset_at_eox = false;
+
/*
* The content of dropped session variables is not removed immediately. If
* possible, we do that at the end of the transaction. But we cannot do that
@@ -385,6 +393,32 @@ remove_invalid_session_variables(bool atEOX)
}
}
+/*
+ * remove entries marked as "reset_at_eox"
+ */
+static void
+remove_session_variables_with_reset_at_eox(void)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ if (!sessionvars)
+ return;
+
+ /* leave quckly, when there are not that variables */
+ if (!has_session_variables_with_reset_at_eox)
+ return;
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (svar->reset_at_eox)
+ hash_search(sessionvars, &svar->varid, HASH_REMOVE, NULL);
+ }
+
+ has_session_variables_with_reset_at_eox = false;
+}
+
/*
* Perform ON COMMIT DROP for temporary session variables,
* and remove all dropped variables from memory.
@@ -392,6 +426,8 @@ remove_invalid_session_variables(bool atEOX)
void
AtPreEOXact_SessionVariables(bool isCommit)
{
+ remove_session_variables_with_reset_at_eox();
+
if (isCommit)
{
if (xact_drop_items)
@@ -503,6 +539,21 @@ setup_session_variable(SVariable svar, Oid varid)
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+ /*
+ * We don't need to explicitly reset variables marked ON COMMIT DROP. It
+ * can be done by sinval message processing. But this processing can be
+ * postponed due aborted transaction. On second hand there is not a
+ * reason, why don't do it at transaction end immediately.
+ */
+ if (varform->varxactendaction == VARIABLE_XACTEND_RESET ||
+ varform->varxactendaction == VARIABLE_XACTEND_DROP)
+ {
+ svar->reset_at_eox = true;
+ has_session_variables_with_reset_at_eox = true;
+ }
+ else
+ svar->reset_at_eox = false;
+
svar->drop_lxid = InvalidTransactionId;
svar->isnull = true;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 4072c155b56..fb8cc863748 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -5293,6 +5293,7 @@ CreateSessionVarStmt:
* transaction end like tables.
*/
XactEndActionOption: ON COMMIT DROP { $$ = VARIABLE_XACTEND_DROP; }
+ | ON TRANSACTION END_P RESET { $$ = VARIABLE_XACTEND_RESET; }
| /*EMPTY*/ { $$ = VARIABLE_XACTEND_NOOP; }
;
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 1c2d71654ea..8da25544ef2 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5471,6 +5471,7 @@ getVariables(Archive *fout)
int i_varnamespace;
int i_vartype;
int i_vartypname;
+ int i_varxactendaction;
int i_varowner;
int i_varcollation;
int i_varacl;
@@ -5486,6 +5487,7 @@ getVariables(Archive *fout)
/* get the variables in current database */
appendPQExpBuffer(query,
"SELECT v.tableoid, v.oid, v.varname,\n"
+ " v.varxactendaction,\n"
" v.varnamespace, v.vartype,\n"
" pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n"
" CASE WHEN v.varcollation <> t.typcollation "
@@ -5508,6 +5510,7 @@ getVariables(Archive *fout)
i_varnamespace = PQfnumber(res, "varnamespace");
i_vartype = PQfnumber(res, "vartype");
i_vartypname = PQfnumber(res, "vartypname");
+ i_varxactendaction = PQfnumber(res, "varxactendaction");
i_varcollation = PQfnumber(res, "varcollation");
i_varowner = PQfnumber(res, "varowner");
@@ -5531,6 +5534,9 @@ getVariables(Archive *fout)
varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype));
varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname));
+ varinfo[i].varxactendaction =
+ pg_strdup(PQgetvalue(res, i, i_varxactendaction));
+
varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
@@ -5571,6 +5577,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
PQExpBuffer query;
char *qualvarname;
const char *vartypname;
+ const char *varxactendaction;
Oid varcollation;
/* skip if not to be dumped */
@@ -5582,6 +5589,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
vartypname = varinfo->vartypname;
+ varxactendaction = varinfo->varxactendaction;
varcollation = varinfo->varcollation;
appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
@@ -5600,6 +5608,9 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
fmtQualifiedDumpable(coll));
}
+ if (strcmp(varxactendaction, "r") == 0)
+ appendPQExpBuffer(query, " ON TRANSACTION END RESET");
+
appendPQExpBuffer(query, ";\n");
if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index d69806ce55c..c8bb78d164c 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -740,6 +740,7 @@ typedef struct _VariableInfo
DumpableAcl dacl;
Oid vartype;
char *vartypname;
+ char *varxactendaction;
Oid varcollation;
const char *rolname; /* name of owner, or empty string */
} VariableInfo;
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 87dbbc9abdb..7fe4cc8f223 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4111,6 +4111,24 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable ON TRANSACTION END RESET' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable2 AS integer ON TRANSACTION END RESET;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable2 AS integer ON TRANSACTION END RESET;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 50ddcc24140..a84222b7762 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5354,6 +5354,7 @@ listVariables(const char *pattern, bool verbose)
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
+ " WHEN 'r' THEN 'ON TRANSACTION END RESET'\n"
" END as \"%s\"\n",
gettext_noop("Schema"),
gettext_noop("Name"),
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 0fc672bc2ba..008f2ee7c17 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -75,6 +75,7 @@ typedef enum VariableXactEndAction
{
VARIABLE_XACTEND_NOOP = 'n', /* NOOP */
VARIABLE_XACTEND_DROP = 'd', /* ON COMMIT DROP */
+ VARIABLE_XACTEND_RESET = 'r', /* ON TRANSACTION END RESET */
} VariableXactEndAction;
/* ----------------
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
index a609797dc5d..e9a254bcd12 100644
--- a/src/test/isolation/expected/session-variable.out
+++ b/src/test/isolation/expected/session-variable.out
@@ -86,11 +86,12 @@ myvar
step sr1: ROLLBACK;
-starting permutation: create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
+starting permutation: create3 let3 s3 o_c_d o_eox_r create4 let4 drop4 drop3 inval3 discard sc3 clean state
step create3: CREATE VARIABLE myvar3 AS text;
step let3: LET myvar3 = 'test';
step s3: BEGIN;
step o_c_d: CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP;
+step o_eox_r: CREATE VARIABLE myvar_o_eox_r AS text ON TRANSACTION END RESET; LET myvar_o_eox_r = 'test';
step create4: CREATE VARIABLE myvar4 AS text;
step let4: LET myvar4 = 'test';
step drop4: DROP VARIABLE myvar4;
@@ -103,6 +104,7 @@ t
step discard: DISCARD VARIABLES;
step sc3: COMMIT;
+step clean: DROP VARIABLE myvar_o_eox_r;
step state: SELECT varname FROM pg_variable;
varname
-------
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
index 45e65d4085d..5d089c8a4ed 100644
--- a/src/test/isolation/specs/session-variable.spec
+++ b/src/test/isolation/specs/session-variable.spec
@@ -25,12 +25,14 @@ session s3
step s3 { BEGIN; }
step let3 { LET myvar3 = 'test'; }
step o_c_d { CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP; }
+step o_eox_r { CREATE VARIABLE myvar_o_eox_r AS text ON TRANSACTION END RESET; LET myvar_o_eox_r = 'test'; }
step create4 { CREATE VARIABLE myvar4 AS text; }
step let4 { LET myvar4 = 'test'; }
step drop4 { DROP VARIABLE myvar4; }
step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; }
step discard { DISCARD VARIABLES; }
step sc3 { COMMIT; }
+step clean { DROP VARIABLE myvar_o_eox_r; }
step state { SELECT varname FROM pg_variable; }
session s4
@@ -48,4 +50,4 @@ permutation let val dbg drop create dbg val
# calling the dbg step after the concurrent drop
permutation let val s1 dbg drop create dbg val sr1
# test for DISCARD ALL when all internal queues have actions registered
-permutation create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
+permutation create3 let3 s3 o_c_d o_eox_r create4 let4 drop4 drop3 inval3 discard sc3 clean state
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index e4297809ea6..a593d05c2ca 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2265,3 +2265,37 @@ SELECT count(*) FROM pg_session_variables();
0
(1 row)
+CREATE VARIABLE var1 AS int ON TRANSACTION END RESET;
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+COMMIT;
+-- should be NULL;
+SELECT var1 IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be NULL
+SELECT var1 IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+DROP VARIABLE var1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index e6ccc37153d..d6e7c21bf16 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1545,3 +1545,23 @@ COMMIT;
SELECT count(*) FROM pg_variable WHERE varname = 'var1';
-- should be zero
SELECT count(*) FROM pg_session_variables();
+
+CREATE VARIABLE var1 AS int ON TRANSACTION END RESET;
+
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+COMMIT;
+
+-- should be NULL;
+SELECT var1 IS NULL;
+
+BEGIN;
+ LET var1 = 100;
+ SELECT var1;
+ROLLBACK;
+
+-- should be NULL
+SELECT var1 IS NULL;
+
+DROP VARIABLE var1;
--
2.48.1
[text/x-patch] v20250301-0014-Implementation-of-NOT-NULL-and-IMMUTABLE-clauses.patch (33.9K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/15-v20250301-0014-Implementation-of-NOT-NULL-and-IMMUTABLE-clauses.patch)
download | inline diff:
From 3173dfa94c24443a88f3109899e6802c07aea8ae Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:05:06 +0100
Subject: [PATCH 14/21] Implementation of NOT NULL and IMMUTABLE clauses
Almost trivial patch - psql, pg_dump support
---
doc/src/sgml/catalogs.sgml | 20 +++
doc/src/sgml/plpgsql.sgml | 3 +-
doc/src/sgml/ref/create_variable.sgml | 32 +++-
src/backend/catalog/pg_variable.c | 8 +
src/backend/commands/session_variable.c | 69 ++++++++-
src/backend/parser/gram.y | 41 +++--
src/bin/pg_dump/pg_dump.c | 19 ++-
src/bin/pg_dump/pg_dump.h | 2 +
src/bin/pg_dump/t/002_pg_dump.pl | 36 +++++
src/bin/psql/describe.c | 6 +-
src/bin/psql/tab-complete.in.c | 12 +-
src/include/catalog/pg_variable.h | 6 +
src/include/nodes/parsenodes.h | 2 +
src/test/regress/expected/psql.out | 36 ++---
.../regress/expected/session_variables.out | 145 ++++++++++++++++++
src/test/regress/sql/session_variables.sql | 122 +++++++++++++++
16 files changed, 518 insertions(+), 41 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 27bdaf62668..c7a8170ddf2 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9867,6 +9867,26 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
<row>
<entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varnotnull</structfield> <type>boolean</type>
+ </para>
+ <para>
+ True if the session variable doesn't allow null values. The default value is false.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varisimmutable</structfield> <type>boolean</type>
+ </para>
+ <para>
+ True if the variable is <link linkend="sql-createvariable-immutable">immutable</link> (cannot be modified).
+ The default value is false.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vareoxaction</structfield> <type>char</type>
<structfield>varxactendaction</structfield> <type>char</type>
</para>
<para>
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index bfbff9ab74e..e704e05a991 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -6044,7 +6044,8 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE;
You can consider translating an Oracle package into a schema in
<productname>PostgreSQL</productname>. Package functions and procedures
would then become functions and procedures in that schema, and package
- variables could be translated to session variables in that schema.
+ variables could be translated to session variables or immutable session
+ variables in that schema.
(see <xref linkend="ddl-session-variables"/>).
</para>
</sect3>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index e4d8851ccb8..3c3e6d55b69 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -26,8 +26,8 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
- [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
+CREATE [ { TEMPORARY | TEMP } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+ [ NOT NULL ] [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -65,6 +65,22 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
<variablelist>
+ <varlistentry id="sql-createvariable-immutable">
+ <term><literal>IMMUTABLE</literal></term>
+ <listitem>
+ <para>
+ The assigned value of the session variable can not be changed.
+ Only if the session variable doesn't have a default value, a single
+ initialization is allowed using the <command>LET</command> command. Once
+ done, no further change is allowed until end of transaction
+ if the session variable was created with clause <literal>ON TRANSACTION
+ END RESET</literal>, or until reset of all session variables by
+ <command>DISCARD VARIABLES</command>, or until reset of all session
+ objects by command <command>DISCARD ALL</command>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createvariable-if-not-exists">
<term><literal>IF NOT EXISTS</literal></term>
<listitem>
@@ -105,6 +121,18 @@ CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="p
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-not-null">
+ <term><literal>NOT NULL</literal></term>
+ <listitem>
+ <para>
+ The <literal>NOT NULL</literal> clause forbids setting the session
+ variable to a null value. A session variable created as NOT NULL
+ should not to have a declared default value, and if the variable
+ has not assigned value, then the reading of this variable fails.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="sql-createvariable-default">
<term><literal>DEFAULT <replaceable>default_expr</replaceable></literal></term>
<listitem>
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 8fba4cc493b..0b6093a00ba 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -40,6 +40,8 @@ static ObjectAddress create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ bool not_null,
+ bool is_immutable,
Node *varDefexpr,
VariableXactEndAction varXactEndAction);
@@ -55,6 +57,8 @@ create_variable(const char *varName,
Oid varOwner,
Oid varCollation,
bool if_not_exists,
+ bool not_null,
+ bool is_immutable,
Node *varDefexpr,
VariableXactEndAction varXactEndAction)
{
@@ -117,6 +121,8 @@ create_variable(const char *varName,
values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+ values[Anum_pg_variable_varnotnull - 1] = BoolGetDatum(not_null);
+ values[Anum_pg_variable_varisimmutable - 1] = BoolGetDatum(is_immutable);
values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
if (varDefexpr)
@@ -259,6 +265,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
varowner,
collation,
stmt->if_not_exists,
+ stmt->not_null,
+ stmt->is_immutable,
cooked_default,
stmt->XactEndAction);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index c12f20eaba7..95dd7445c15 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -84,6 +84,9 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ bool not_null;
+ bool is_immutable;
+
bool reset_at_eox;
/*
@@ -102,6 +105,9 @@ typedef struct SVariableData
bool is_valid;
uint32 hashvalue; /* used for pairing sinval message */
+
+ /* true, when the value is already set, and cannot be changed more */
+ bool protect_value;
} SVariableData;
typedef SVariableData *SVariable;
@@ -563,6 +569,23 @@ eval_assign_defexpr(SVariable svar, HeapTuple tup)
MemoryContextSwitchTo(oldcxt);
}
+ else
+ {
+ /*
+ * Raise an error if this is a NOT NULL variable but the result of
+ * DEFAULT expression is NULL.
+ */
+ if (svar->not_null)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("null value is not allowed for NOT NULL session variable \"%s.%s\"",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid)),
+ errdetail("The result of DEFAULT expression is NULL.")));
+ }
+
+ if (svar->is_immutable)
+ svar->protect_value = true;
FreeExecutorState(estate);
}
@@ -593,6 +616,9 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval);
+ svar->not_null = varform->varnotnull;
+ svar->is_immutable = varform->varisimmutable;
+
svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
@@ -622,9 +648,31 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
ObjectIdGetDatum(varid));
- if (!is_write)
+ svar->protect_value = false;
+
+ /*
+ * When the variable is marked as IMMUTABLE, we prefer to evaluate
+ * possible DEFAULT before write op. In this case we want to protect
+ * default value against any overwrite.
+ */
+ if (!is_write ||
+ svar->is_immutable)
+ {
eval_assign_defexpr(svar, tup);
+ /*
+ * Raise an error if this is a NOT NULL variable without default
+ * expression.
+ */
+ if (svar->isnull && svar->not_null)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("null value is not allowed for NOT NULL session variable \"%s.%s\"",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ errdetail("The session variable was not initialized yet.")));
+ }
+
ReleaseSysCache(tup);
}
@@ -644,6 +692,21 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
Assert(svar);
Assert(!isnull || value == (Datum) 0);
+ if (svar->protect_value)
+ ereport(ERROR,
+ (errcode(ERRCODE_ERROR_IN_ASSIGNMENT),
+ errmsg("session variable \"%s.%s\" is declared IMMUTABLE",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid))));
+
+ /* don't allow assignment of null to NOT NULL variable */
+ if (isnull && svar->not_null)
+ ereport(ERROR,
+ (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ errmsg("null value is not allowed for NOT NULL session variable \"%s.%s\"",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid))));
+
/*
* Use typbyval, typbylen from session variable only when they are
* trustworthy (the invalidation message was not accepted for this
@@ -684,6 +747,10 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
svar->value = newval;
svar->isnull = isnull;
+
+ /* don't allow more changes of value when variable is IMMUTABLE */
+ if (svar->is_immutable)
+ svar->protect_value = true;
}
/*
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 6ee6ed43b8c..53284c0289c 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -675,6 +675,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
json_object_constructor_null_clause_opt
json_array_constructor_null_clause_opt
+%type <boolean> OptNotNull OptImmutable
/*
* Non-keyword token types. These are hard-wired into the "flex" lexer.
@@ -5265,27 +5266,31 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
+ CREATE OptTemp OptImmutable VARIABLE qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $4->relpersistence = $2;
- n->variable = $4;
- n->typeName = $6;
- n->collClause = (CollateClause *) $7;
- n->defexpr = $8;
- n->XactEndAction = $9;
+ $5->relpersistence = $2;
+ n->is_immutable = $3;
+ n->variable = $5;
+ n->typeName = $7;
+ n->collClause = (CollateClause *) $8;
+ n->not_null = $9;
+ n->defexpr = $10;
+ n->XactEndAction = $11;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptSessionVarDefExpr XactEndActionOption
+ | CREATE OptTemp OptImmutable VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $7->relpersistence = $2;
- n->variable = $7;
- n->typeName = $9;
- n->collClause = (CollateClause *) $10;
- n->defexpr = $11;
- n->XactEndAction = $12;
+ $8->relpersistence = $2;
+ n->is_immutable = $3;
+ n->variable = $8;
+ n->typeName = $10;
+ n->collClause = (CollateClause *) $11;
+ n->not_null = $12;
+ n->defexpr = $13;
+ n->XactEndAction = $14;
n->if_not_exists = true;
$$ = (Node *) n;
}
@@ -5305,6 +5310,14 @@ XactEndActionOption: ON COMMIT DROP { $$ = VARIABLE_XACTEND_DROP; }
;
+OptNotNull: NOT NULL_P { $$ = true; }
+ | /* EMPTY */ { $$ = false; }
+ ;
+
+OptImmutable: IMMUTABLE { $$ = true; }
+ | /* EMPTY */ { $$ = false; }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index acd370c3f20..ca8e496ce26 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5475,6 +5475,8 @@ getVariables(Archive *fout)
int i_varxactendaction;
int i_varowner;
int i_varcollation;
+ int i_varnotnull;
+ int i_varisimmutable;
int i_varacl;
int i_acldefault;
int i,
@@ -5495,6 +5497,8 @@ getVariables(Archive *fout)
" THEN v.varcollation\n"
" ELSE 0\n"
" END AS varcollation,\n"
+ " v.varnotnull,\n"
+ " v.varisimmutable,\n"
" pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n"
" v.varowner, v.varacl,\n"
" acldefault('V', v.varowner) AS acldefault\n"
@@ -5515,6 +5519,8 @@ getVariables(Archive *fout)
i_vardefexpr = PQfnumber(res, "vardefexpr");
i_varxactendaction = PQfnumber(res, "varxactendaction");
i_varcollation = PQfnumber(res, "varcollation");
+ i_varnotnull = PQfnumber(res, "varnotnull");
+ i_varisimmutable = PQfnumber(res, "varisimmutable");
i_varowner = PQfnumber(res, "varowner");
i_varacl = PQfnumber(res, "varacl");
@@ -5541,6 +5547,8 @@ getVariables(Archive *fout)
pg_strdup(PQgetvalue(res, i, i_varxactendaction));
varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
+ varinfo[i].varnotnull = *(PQgetvalue(res, i, i_varnotnull)) == 't';
+ varinfo[i].varisimmutable = *(PQgetvalue(res, i, i_varisimmutable)) == 't';
varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
@@ -5587,7 +5595,9 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
const char *vartypname;
const char *vardefexpr;
const char *varxactendaction;
+ const char *varisimmutable;
Oid varcollation;
+ bool varnotnull;
/* skip if not to be dumped */
if (!varinfo->dobj.dump || !dopt->dumpSchema)
@@ -5601,12 +5611,14 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
vardefexpr = varinfo->vardefexpr;
varxactendaction = varinfo->varxactendaction;
varcollation = varinfo->varcollation;
+ varnotnull = varinfo->varnotnull;
+ varisimmutable = varinfo->varisimmutable ? "IMMUTABLE " : "";
appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
qualvarname);
- appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s",
- qualvarname, vartypname);
+ appendPQExpBuffer(query, "CREATE %sVARIABLE %s AS %s",
+ varisimmutable, qualvarname, vartypname);
if (OidIsValid(varcollation))
{
@@ -5618,6 +5630,9 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
fmtQualifiedDumpable(coll));
}
+ if (varnotnull)
+ appendPQExpBuffer(query, " NOT NULL");
+
if (vardefexpr)
appendPQExpBuffer(query, " DEFAULT %s",
vardefexpr);
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index b94c03b647d..f1ee2d3eff6 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -744,6 +744,8 @@ typedef struct _VariableInfo
char *varxactendaction;
Oid varcollation;
const char *rolname; /* name of owner, or empty string */
+ bool varnotnull;
+ bool varisimmutable;
} VariableInfo;
/*
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 33656196d92..b955bc7cec2 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4165,6 +4165,42 @@ my %tests = (
},
},
+ 'CREATE IMMUTABLE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE IMMUTABLE VARIABLE dump_test.variable5 AS integer',
+ regexp => qr/^
+ \QCREATE IMMUTABLE VARIABLE dump_test.variable5 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
+ 'CREATE IMMUTABLE VARIABLE test_variable NOT NULL DEFAULT' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE IMMUTABLE VARIABLE dump_test.variable7 AS integer NOT NULL DEFAULT 10',
+ regexp => qr/^
+ \QCREATE IMMUTABLE VARIABLE dump_test.variable7 AS integer NOT NULL DEFAULT 10;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 7780fc232ff..503ae160398 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5352,6 +5352,8 @@ listVariables(const char *pattern, bool verbose)
" (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
" WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
+ " NOT v.varnotnull as \"%s\",\n"
+ " NOT v.varisimmutable as \"%s\",\n"
" pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
@@ -5362,6 +5364,8 @@ listVariables(const char *pattern, bool verbose)
gettext_noop("Type"),
gettext_noop("Collation"),
gettext_noop("Owner"),
+ gettext_noop("Nullable"),
+ gettext_noop("Mutable"),
gettext_noop("Default"),
gettext_noop("Transactional end action"));
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index e151eaa7498..7594ce2fa18 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1287,6 +1287,8 @@ static const pgsql_thing_t words_after_create[] = {
{"FOREIGN TABLE", NULL, NULL, NULL},
{"FUNCTION", NULL, NULL, Query_for_list_of_functions},
{"GROUP", Query_for_list_of_roles},
+ {"IMMUTABLE VARIABLE", NULL, NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE IMMUTABLE
+ * VARIABLE ... */
{"INDEX", NULL, NULL, &Query_for_list_of_indexes},
{"LANGUAGE", Query_for_list_of_languages},
{"LARGE OBJECT", NULL, NULL, NULL, NULL, THING_NO_CREATE | THING_NO_DROP},
@@ -3637,7 +3639,8 @@ match_previous_words(int pattern_id,
/* CREATE TABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete "CREATE TEMP/TEMPORARY" with the possible temp objects */
else if (TailMatches("CREATE", "TEMP|TEMPORARY"))
- COMPLETE_WITH("SEQUENCE", "TABLE", "VARIABLE", "VIEW");
+ COMPLETE_WITH("IMMUTABLE VARIABLE", "SEQUENCE", "TABLE", "VARIABLE",
+ "VIEW");
/* Complete "CREATE UNLOGGED" with TABLE or SEQUENCE */
else if (TailMatches("CREATE", "UNLOGGED"))
COMPLETE_WITH("TABLE", "SEQUENCE");
@@ -3989,7 +3992,8 @@ match_previous_words(int pattern_id,
/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE VARIABLE <name> with AS */
else if (TailMatches("CREATE", "VARIABLE", MatchAny) ||
- TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny))
+ TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny) ||
+ TailMatches("IMMUTABLE", "VARIABLE", MatchAny))
COMPLETE_WITH("AS");
else if (TailMatches("VARIABLE", MatchAny, "AS"))
/* Complete CREATE VARIABLE <name> with AS types */
@@ -4649,6 +4653,10 @@ match_previous_words(int pattern_id,
else if (TailMatches("FROM", "SERVER", MatchAny, "INTO", MatchAny))
COMPLETE_WITH("OPTIONS (");
+/* IMMUTABLE -- can be expend to IMMUTABLE VARIABLE */
+ else if (TailMatches("CREATE", "IMMUTABLE"))
+ COMPLETE_WITH("VARIABLE");
+
/* INSERT --- can be inside EXPLAIN, RULE, etc */
/* Complete NOT MATCHED THEN INSERT */
else if (TailMatches("NOT", "MATCHED", "THEN", "INSERT"))
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 09dd44a44e1..cf21e0426a7 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -56,6 +56,12 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* typmod for variable's type */
int32 vartypmod BKI_DEFAULT(-1);
+ /* don't allow NULL */
+ bool varnotnull BKI_DEFAULT(f);
+
+ /* don't allow changes */
+ bool varisimmutable BKI_DEFAULT(f);
+
/* action on transaction end */
char varxactendaction BKI_DEFAULT(n);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 67ef92685fd..785354ab52c 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3546,6 +3546,8 @@ typedef struct CreateSessionVarStmt
TypeName *typeName; /* the type of variable */
CollateClause *collClause;
bool if_not_exists; /* do nothing if it already exists */
+ bool not_null; /* disallow nulls */
+ bool is_immutable; /* don't allow changes */
Node *defexpr; /* default expression */
char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index c5380d1d855..02a729f1993 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6026,20 +6026,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+---------+--------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | | | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+---------+--------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | | | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6507,9 +6507,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action
---------+------+------+-----------+-------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6682,9 +6682,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action
---------+------+------+-----------+-------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6821,9 +6821,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Default | Transactional end action
---------+------+------+-----------+-------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 84c681ff716..ba33d366091 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2362,3 +2362,148 @@ SELECT var1;
DROP VARIABLE var1;
DROP FUNCTION vartest_fx();
+-- test NOT NULL
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL;
+-- should to fail
+SELECT var1;
+ERROR: null value is not allowed for NOT NULL session variable "public.var1"
+DETAIL: The session variable was not initialized yet.
+--should be ok
+LET var1 = 10;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1;
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT 0;
+--should be ok
+SELECT var1;
+ var1
+------
+ 0
+(1 row)
+
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DISCARD VARIABLES;
+-- should to fail
+LET var1 = NULL;
+ERROR: null value is not allowed for NOT NULL session variable "public.var1"
+DROP VARIABLE var1;
+-- test NOT NULL
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN NULL;
+END;
+$$ LANGUAGE plpgsql;
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT vartest_fx();
+-- should to fail
+SELECT var1;
+ERROR: null value is not allowed for NOT NULL session variable "public.var1"
+DETAIL: The result of DEFAULT expression is NULL.
+DISCARD VARIABLES;
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+DISCARD VARIABLES;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 0
+(1 row)
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
+-- test IMMUTBLE
+CREATE IMMUTABLE VARIABLE var1 AS int;
+-- should be ok
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+-- first write should ok
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DISCARD VARIABLES;
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DISCARD VARIABLES;
+-- should be ok
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+-- should be ok
+LET var1 = NULL;
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DROP VARIABLE var1;
+CREATE IMMUTABLE VARIABLE var1 AS int DEFAULT 10;
+-- don't allow change when variable has DEFAULT value
+-- should to fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DISCARD VARIABLES;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- should fail
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DROP VARIABLE var1;
+-- should be ok
+CREATE IMMUTABLE VARIABLE var1 AS INT NOT NULL DEFAULT 10;
+-- should to fail
+LET var1 = 10;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+LET var1 = 20;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- should to fail
+LET var1 = 30;
+ERROR: session variable "public.var1" is declared IMMUTABLE
+DROP VARIABLE var1;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 2c7388639d9..282ba5c8639 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1613,3 +1613,125 @@ SELECT var1;
DROP VARIABLE var1;
DROP FUNCTION vartest_fx();
+
+-- test NOT NULL
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL;
+-- should to fail
+SELECT var1;
+
+--should be ok
+LET var1 = 10;
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- should be ok
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT 0;
+
+--should be ok
+SELECT var1;
+
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+
+DISCARD VARIABLES;
+
+-- should to fail
+LET var1 = NULL;
+
+DROP VARIABLE var1;
+
+-- test NOT NULL
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN NULL;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE VARIABLE var1 AS int NOT NULL DEFAULT vartest_fx();
+
+-- should to fail
+SELECT var1;
+
+DISCARD VARIABLES;
+
+-- should be ok
+LET var1 = 10;
+SELECT var1;
+
+CREATE OR REPLACE FUNCTION vartest_fx()
+RETURNS int AS $$
+BEGIN
+ RETURN 0;
+END;
+$$ LANGUAGE plpgsql;
+
+DISCARD VARIABLES;
+
+-- should be ok
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP FUNCTION vartest_fx();
+
+-- test IMMUTBLE
+CREATE IMMUTABLE VARIABLE var1 AS int;
+
+-- should be ok
+SELECT var1;
+-- first write should ok
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+
+DISCARD VARIABLES;
+
+-- should be ok
+LET var1 = 10;
+-- should fail
+LET var1 = 20;
+
+DISCARD VARIABLES;
+
+-- should be ok
+SELECT var1;
+-- should be ok
+LET var1 = NULL;
+-- should fail
+LET var1 = 20;
+
+DROP VARIABLE var1;
+
+CREATE IMMUTABLE VARIABLE var1 AS int DEFAULT 10;
+
+-- don't allow change when variable has DEFAULT value
+-- should to fail
+LET var1 = 20;
+
+DISCARD VARIABLES;
+
+-- should be ok
+SELECT var1;
+-- should fail
+LET var1 = 20;
+
+DROP VARIABLE var1;
+
+-- should be ok
+CREATE IMMUTABLE VARIABLE var1 AS INT NOT NULL DEFAULT 10;
+
+-- should to fail
+LET var1 = 10;
+LET var1 = 20;
+
+-- should be ok
+SELECT var1;
+
+-- should to fail
+LET var1 = 30;
+
+DROP VARIABLE var1;
--
2.48.1
[text/x-patch] v20250301-0011-implementation-of-temporary-session-variables.patch (40.7K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/16-v20250301-0011-implementation-of-temporary-session-variables.patch)
download | inline diff:
From 35f869fe679b0b8db3a73ebb9b0fc3038d033dbb Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:00:28 +0100
Subject: [PATCH 11/21] implementation of temporary session variables
The temporary variables are created inside temp schema and they are dropped by dropping
this schema. For consistency with temp tables, the CREATE TEMP VARIABLE command supports
ON COMMIT DROP clause. The temporary variables with this clause are collected in xact_drop_items
list. This list should be carefully maintained and can contain only valid entries (not
yet dropped). From this reasons now the subcommit and subaborting have to be handled.
---
doc/src/sgml/catalogs.sgml | 10 +
doc/src/sgml/ddl.sgml | 6 +-
doc/src/sgml/ref/create_variable.sgml | 15 +-
src/backend/access/transam/xact.c | 9 +
src/backend/catalog/pg_variable.c | 27 ++-
src/backend/commands/session_variable.c | 218 +++++++++++++++++-
src/backend/commands/view.c | 2 +-
src/backend/parser/analyze.c | 4 +-
src/backend/parser/gram.y | 30 ++-
src/backend/parser/parse_relation.c | 22 +-
src/bin/psql/describe.c | 10 +-
src/bin/psql/tab-complete.in.c | 5 +-
src/include/catalog/pg_variable.h | 9 +
src/include/commands/session_variable.h | 6 +-
src/include/nodes/parsenodes.h | 1 +
src/include/nodes/primnodes.h | 4 +-
src/include/parser/parse_relation.h | 2 +-
.../isolation/expected/session-variable.out | 3 +-
.../isolation/specs/session-variable.spec | 3 +-
src/test/regress/expected/psql.out | 36 +--
.../regress/expected/session_variables.out | 120 ++++++++++
src/test/regress/sql/session_variables.sql | 66 ++++++
src/tools/pgindent/typedefs.list | 1 +
23 files changed, 544 insertions(+), 65 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 4f502274bfa..09b635c234a 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9865,6 +9865,16 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varxactendaction</structfield> <type>char</type>
+ </para>
+ <para>
+ Action performed at end of transaction:
+ <literal>n</literal> = no action, <literal>d</literal> = drop the variable.
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>varcollation</structfield> <type>oid</type>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 4e8e7c6a42a..3e2cb3c46eb 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5412,9 +5412,9 @@ SELECT current_user_id;
<command>LET</command> command. Session variables are not transactional:
any changes made to the value of a session variable in a transaction won't
be undone if the transaction is rolled back (just like variables in
- procedural languages). Session variables themselves are persistent, but
- their values are neither persistent nor shared (like the content of
- temporary tables).
+ procedural languages). Session variables themselves can be persistent
+ or temporary, but their values are neither persistent nor shared (like the
+ content of temporary tables).
</para>
<para>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index cd9ff63975a..a88e0175bea 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -26,7 +26,8 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+CREATE [ { TEMPORARY | TEMP } ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+ [ ON COMMIT DROP ]
</synopsis>
</refsynopsisdiv>
<refsect1>
@@ -104,6 +105,18 @@ CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceab
</listitem>
</varlistentry>
+ <varlistentry id="sql-createvariable-on-commit-drop">
+ <term><literal>ON COMMIT DROP</literal></term>
+ <listitem>
+ <para>
+ The <literal>ON COMMIT DROP</literal> clause specifies the behaviour of a
+ temporary session variable at transaction commit. With this clause, the
+ session variable is dropped at commit time. The clause is only allowed
+ for temporary variables.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</refsect1>
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 1b4f21a88d3..4e6216306da 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -36,6 +36,7 @@
#include "catalog/pg_enum.h"
#include "catalog/storage.h"
#include "commands/async.h"
+#include "commands/session_variable.h"
#include "commands/tablecmds.h"
#include "commands/trigger.h"
#include "common/pg_prng.h"
@@ -2316,6 +2317,9 @@ CommitTransaction(void)
*/
smgrDoPendingSyncs(true, is_parallel_worker);
+ /* remove values of dropped session variables from memory */
+ AtPreEOXact_SessionVariables(true);
+
/* close large objects before lower-level cleanup */
AtEOXact_LargeObject(true);
@@ -2912,6 +2916,7 @@ AbortTransaction(void)
AtAbort_Portals();
smgrDoPendingSyncs(false, is_parallel_worker);
AtEOXact_LargeObject(false);
+ AtPreEOXact_SessionVariables(false);
AtAbort_Notify();
AtEOXact_RelationMap(false, is_parallel_worker);
AtAbort_Twophase();
@@ -5177,6 +5182,8 @@ CommitSubTransaction(void)
AtEOSubXact_SPI(true, s->subTransactionId);
AtEOSubXact_on_commit_actions(true, s->subTransactionId,
s->parent->subTransactionId);
+ AtEOSubXact_SessionVariables(true, s->subTransactionId,
+ s->parent->subTransactionId);
AtEOSubXact_Namespace(true, s->subTransactionId,
s->parent->subTransactionId);
AtEOSubXact_Files(true, s->subTransactionId,
@@ -5342,6 +5349,8 @@ AbortSubTransaction(void)
AtEOSubXact_SPI(false, s->subTransactionId);
AtEOSubXact_on_commit_actions(false, s->subTransactionId,
s->parent->subTransactionId);
+ AtEOSubXact_SessionVariables(false, s->subTransactionId,
+ s->parent->subTransactionId);
AtEOSubXact_Namespace(false, s->subTransactionId,
s->parent->subTransactionId);
AtEOSubXact_Files(false, s->subTransactionId,
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index d672d2a9cb3..00c90ea6fd8 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -36,7 +36,8 @@ static ObjectAddress create_variable(const char *varName,
int32 varTypmod,
Oid varOwner,
Oid varCollation,
- bool if_not_exists);
+ bool if_not_exists,
+ VariableXactEndAction varXactEndAction);
/*
@@ -49,7 +50,8 @@ create_variable(const char *varName,
int32 varTypmod,
Oid varOwner,
Oid varCollation,
- bool if_not_exists)
+ bool if_not_exists,
+ VariableXactEndAction varXactEndAction)
{
Acl *varacl;
NameData varname;
@@ -110,6 +112,7 @@ create_variable(const char *varName,
values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+ values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
varNamespace);
@@ -183,6 +186,13 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
Oid typcollation;
ObjectAddress variable;
+ /* check consistency of arguments */
+ if (stmt->XactEndAction == VARIABLE_XACTEND_DROP
+ && stmt->variable->relpersistence != RELPERSISTENCE_TEMP)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+ errmsg("ON COMMIT DROP can only be used on temporary variables")));
+
namespaceid =
RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL);
@@ -222,11 +232,17 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
typmod,
varowner,
collation,
- stmt->if_not_exists);
+ stmt->if_not_exists,
+ stmt->XactEndAction);
elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
stmt->variable->relname, variable.objectId);
+ /* we want SessionVariableCreatePostprocess to see the catalog changes. */
+ CommandCounterIncrement();
+
+ SessionVariableCreatePostprocess(variable.objectId, stmt->XactEndAction);
+
return variable;
}
@@ -239,6 +255,7 @@ DropVariableById(Oid varid)
{
Relation rel;
HeapTuple tup;
+ char XactEndAction;
rel = table_open(VariableRelationId, RowExclusiveLock);
@@ -247,6 +264,8 @@ DropVariableById(Oid varid)
if (!HeapTupleIsValid(tup))
elog(ERROR, "cache lookup failed for variable %u", varid);
+ XactEndAction = ((Form_pg_variable) GETSTRUCT(tup))->varxactendaction;
+
CatalogTupleDelete(rel, &tup->t_self);
ReleaseSysCache(tup);
@@ -254,5 +273,5 @@ DropVariableById(Oid varid)
table_close(rel, RowExclusiveLock);
/* do the necessary cleanup in local memory, if needed */
- SessionVariableDropPostprocess(varid);
+ SessionVariableDropPostprocess(varid, XactEndAction);
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 1596d94fb03..dc51a778bf5 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -16,6 +16,8 @@
#include "access/xact.h"
#include "catalog/pg_variable.h"
+#include "catalog/dependency.h"
+#include "catalog/namespace.h"
#include "commands/session_variable.h"
#include "executor/svariableReceiver.h"
#include "funcapi.h"
@@ -31,6 +33,19 @@
#include "utils/snapmgr.h"
#include "utils/syscache.h"
+typedef struct SVariableXActDropItem
+{
+ Oid varid; /* varid of session variable */
+
+ /*
+ * creating_subid is the ID of the creating subxact. If the action was
+ * unregistered during the current transaction, deleting_subid is the ID
+ * of the deleting subxact, otherwise InvalidSubTransactionId.
+ */
+ SubTransactionId creating_subid;
+ SubTransactionId deleting_subid;
+} SVariableXActDropItem;
+
/*
* The values of session variables are stored in the backend's private memory
* in the dedicated memory context SVariableMemoryContext in binary format.
@@ -96,13 +111,21 @@ static MemoryContext SVariableMemoryContext = NULL;
static bool needs_validation = false;
/*
- * The content of dropped session variables is not removed immediately. We do
- * that in the next transaction that reads or writes a session variable.
- * "validated_lxid" stores the transaction that performed said validation, so
- * that we can avoid repeating the effort.
+ * The content of dropped session variables is not removed immediately. If
+ * possible, we do that at the end of the transaction. But we cannot do that
+ * if the transaction aborted, because we lost access to the system catalog.
+ * In that case, we clean up in the next transaction that reads or writes a
+ * session variable. "validated_lxid" stores the transaction that performed
+ * said validation, so that we can avoid repeating the effort.
*/
static LocalTransactionId validated_lxid = InvalidLocalTransactionId;
+/* list holds fields of SVariableXActDropItem type */
+static List *xact_drop_items = NIL;
+
+static void register_session_variable_xact_drop(Oid varid);
+static void unregister_session_variable_xact_drop(Oid varid);
+
/*
* Callback function for session variable invalidation.
*/
@@ -139,16 +162,45 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
}
}
+/*
+ * Do the necessary work to setup local memory management of a new
+ * variable.
+ *
+ * Caller should already have created the necessary entry in catalog
+ * and made them visible.
+ */
+void
+SessionVariableCreatePostprocess(Oid varid, char XactEndAction)
+{
+ /*
+ * For temporary variables, we need to create a new end of xact action to
+ * ensure deletion from catalog.
+ */
+ if (XactEndAction == VARIABLE_XACTEND_DROP)
+ {
+ Assert(isTempNamespace(get_session_variable_namespace(varid)));
+
+ register_session_variable_xact_drop(varid);
+ }
+}
+
/*
* Handle the local memory cleanup for a DROP VARIABLE command.
*
* Caller should take care of removing the pg_variable entry first.
*/
void
-SessionVariableDropPostprocess(Oid varid)
+SessionVariableDropPostprocess(Oid varid, char XactEndAction)
{
Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid));
+ if (XactEndAction == VARIABLE_XACTEND_DROP)
+ {
+ Assert(isTempNamespace(get_session_variable_namespace(varid)));
+
+ unregister_session_variable_xact_drop(varid);
+ }
+
if (sessionvars)
{
bool found;
@@ -170,6 +222,57 @@ SessionVariableDropPostprocess(Oid varid)
}
}
+/*
+ * Registration of actions to be executed on session variables at transaction
+ * end time. We want to drop temporary session variables with clause ON COMMIT
+ * DROP.
+ */
+
+/*
+ * Register a session variable xact action.
+ */
+static void
+register_session_variable_xact_drop(Oid varid)
+{
+ SVariableXActDropItem *xact_ai;
+ MemoryContext oldcxt;
+
+ oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
+
+ xact_ai = (SVariableXActDropItem *)
+ palloc(sizeof(SVariableXActDropItem));
+
+ xact_ai->varid = varid;
+
+ xact_ai->creating_subid = GetCurrentSubTransactionId();
+ xact_ai->deleting_subid = InvalidSubTransactionId;
+
+ xact_drop_items = lcons(xact_ai, xact_drop_items);
+
+ MemoryContextSwitchTo(oldcxt);
+}
+
+/*
+ * Unregister an id of a given session variable from drop list. In this
+ * moment, the action is just marked as deleted by setting deleting_subid. The
+ * calling even might be rollbacked, in which case we should not lose this
+ * action.
+ */
+static void
+unregister_session_variable_xact_drop(Oid varid)
+{
+ ListCell *l;
+
+ foreach(l, xact_drop_items)
+ {
+ SVariableXActDropItem *xact_ai =
+ (SVariableXActDropItem *) lfirst(l);
+
+ if (xact_ai->varid == varid)
+ xact_ai->deleting_subid = GetCurrentSubTransactionId();
+ }
+}
+
/*
* Release stored value, free memory
*/
@@ -222,9 +325,11 @@ is_session_variable_valid(SVariable svar)
/*
* Check all potentially invalid session variable data in local memory and free
* the memory for all invalid ones. This function is called before any read or
- * write of a session variable. Freeing of a variable's memory is postponed if
- * the variable has been dropped by the current transaction, since that
- * operation could still be rolled back.
+ * write of a session variable or when the transaction ends. At the end of a
+ * transaction (atEOX is true) we can discard all invalid variables. Inside a
+ * transaction (atEOX is false) we postpone freeing a variable's memory if the
+ * variable has been dropped by the current transaction, since that operation
+ * could still be rolled back.
*
* It is possible that we receive a cache invalidation message while
* remove_invalid_session_variables() is executing, so we cannot guarantee that
@@ -232,7 +337,7 @@ is_session_variable_valid(SVariable svar)
* done. However, we can guarantee that all entries get checked once.
*/
static void
-remove_invalid_session_variables(void)
+remove_invalid_session_variables(bool atEOX)
{
HASH_SEQ_STATUS status;
SVariable svar;
@@ -259,7 +364,7 @@ remove_invalid_session_variables(void)
{
if (!svar->is_valid)
{
- if (svar->drop_lxid == MyProc->vxid.lxid)
+ if (!atEOX && svar->drop_lxid == MyProc->vxid.lxid)
{
/* try again in the next transaction */
needs_validation = true;
@@ -280,6 +385,95 @@ remove_invalid_session_variables(void)
}
}
+/*
+ * Perform ON COMMIT DROP for temporary session variables,
+ * and remove all dropped variables from memory.
+ */
+void
+AtPreEOXact_SessionVariables(bool isCommit)
+{
+ if (isCommit)
+ {
+ if (xact_drop_items)
+ {
+ ListCell *l;
+
+ foreach(l, xact_drop_items)
+ {
+ SVariableXActDropItem *xact_ai =
+ (SVariableXActDropItem *) lfirst(l);
+
+ /* iterate only over entries that are still pending */
+ if (xact_ai->deleting_subid == InvalidSubTransactionId)
+ {
+ ObjectAddress object;
+
+ object.classId = VariableRelationId;
+ object.objectId = xact_ai->varid;
+ object.objectSubId = 0;
+
+ /*
+ * Since this is an automatic drop, rather than one
+ * directly initiated by the user, we pass the
+ * PERFORM_DELETION_INTERNAL flag.
+ */
+ elog(DEBUG1, "session variable (oid:%u) will be deleted (forced by ON COMMIT DROP clause)",
+ xact_ai->varid);
+
+ performDeletion(&object, DROP_CASCADE,
+ PERFORM_DELETION_INTERNAL |
+ PERFORM_DELETION_QUIETLY);
+ }
+ }
+ }
+
+ remove_invalid_session_variables(true);
+ }
+
+ /*
+ * We have to clean xact_drop_items. All related variables are dropped
+ * now, or lost inside aborted transaction.
+ */
+ list_free_deep(xact_drop_items);
+ xact_drop_items = NULL;
+}
+
+/*
+ * Post-subcommit or post-subabort cleanup of xact drop list.
+ *
+ * During subabort, we can immediately remove entries created during this
+ * subtransaction. During subcommit, just transfer entries marked during
+ * this subtransaction as being the parent's responsibility.
+ */
+void
+AtEOSubXact_SessionVariables(bool isCommit,
+ SubTransactionId mySubid,
+ SubTransactionId parentSubid)
+{
+ ListCell *cur_item;
+
+ foreach(cur_item, xact_drop_items)
+ {
+ SVariableXActDropItem *xact_ai =
+ (SVariableXActDropItem *) lfirst(cur_item);
+
+ if (!isCommit && xact_ai->creating_subid == mySubid)
+ {
+ /* cur_item must be removed */
+ xact_drop_items = foreach_delete_current(xact_drop_items, cur_item);
+ pfree(xact_ai);
+ }
+ else
+ {
+ /* cur_item must be preserved */
+ if (xact_ai->creating_subid == mySubid)
+ xact_ai->creating_subid = parentSubid;
+ if (xact_ai->deleting_subid == mySubid)
+ xact_ai->deleting_subid = isCommit ? parentSubid : InvalidSubTransactionId;
+ }
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
@@ -438,7 +632,7 @@ get_session_variable(Oid varid)
validated_lxid != MyProc->vxid.lxid)
{
/* free the memory from dropped session variables */
- remove_invalid_session_variables();
+ remove_invalid_session_variables(false);
/* don't repeat the above step in the same transaction */
validated_lxid = MyProc->vxid.lxid;
@@ -534,7 +728,7 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
validated_lxid != MyProc->vxid.lxid)
{
/* free the memory from dropped session variables */
- remove_invalid_session_variables();
+ remove_invalid_session_variables(false);
/* don't repeat the above step in the same transaction */
validated_lxid = MyProc->vxid.lxid;
diff --git a/src/backend/commands/view.c b/src/backend/commands/view.c
index 6f0301555e0..6bef9a2612a 100644
--- a/src/backend/commands/view.c
+++ b/src/backend/commands/view.c
@@ -484,7 +484,7 @@ DefineView(ViewStmt *stmt, const char *queryString,
*/
view = copyObject(stmt->view); /* don't corrupt original command */
if (view->relpersistence == RELPERSISTENCE_PERMANENT
- && isQueryUsingTempRelation(viewParse))
+ && isQueryUsingTempObject(viewParse))
{
view->relpersistence = RELPERSISTENCE_TEMP;
ereport(NOTICE,
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 725f678e2fa..c0c3abd7a0e 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -3491,10 +3491,10 @@ transformCreateTableAsStmt(ParseState *pstate, CreateTableAsStmt *stmt)
* creation query. It would be hard to refresh data or incrementally
* maintain it if a source disappeared.
*/
- if (isQueryUsingTempRelation(query))
+ if (isQueryUsingTempObject(query))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("materialized views must not use temporary tables or views")));
+ errmsg("materialized views must not use temporary tables, views or session variables")));
/*
* A materialized view would either need to save parameters for use in
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index ed656ba6364..4072c155b56 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -473,6 +473,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <ival> OptTemp
%type <ival> OptNoLog
%type <oncommit> OnCommitOption
+%type <ival> XactEndActionOption
%type <ival> for_locking_strength
%type <node> for_locking_item
@@ -5263,26 +5264,39 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause
+ CREATE OptTemp VARIABLE qualified_name opt_as Typename opt_collate_clause XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- n->variable = $3;
- n->typeName = $5;
- n->collClause = (CollateClause *) $6;
+ $4->relpersistence = $2;
+ n->variable = $4;
+ n->typeName = $6;
+ n->collClause = (CollateClause *) $7;
+ n->XactEndAction = $8;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause
+ | CREATE OptTemp VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- n->variable = $6;
- n->typeName = $8;
- n->collClause = (CollateClause *) $9;
+ $7->relpersistence = $2;
+ n->variable = $7;
+ n->typeName = $9;
+ n->collClause = (CollateClause *) $10;
+ n->XactEndAction = $11;
n->if_not_exists = true;
$$ = (Node *) n;
}
;
+/*
+ * Temporary session variables can be dropped on successful
+ * transaction end like tables.
+ */
+XactEndActionOption: ON COMMIT DROP { $$ = VARIABLE_XACTEND_DROP; }
+ | /*EMPTY*/ { $$ = VARIABLE_XACTEND_NOOP; }
+ ;
+
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index 04ecf64b1fc..bec6947ea2d 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -103,7 +103,7 @@ static void expandTupleDesc(TupleDesc tupdesc, Alias *eref,
static int specialAttNum(const char *attname);
static bool rte_visible_if_lateral(ParseState *pstate, RangeTblEntry *rte);
static bool rte_visible_if_qualified(ParseState *pstate, RangeTblEntry *rte);
-static bool isQueryUsingTempRelation_walker(Node *node, void *context);
+static bool isQueryUsingTempObject_walker(Node *node, void *context);
/*
@@ -3927,13 +3927,13 @@ rte_visible_if_qualified(ParseState *pstate, RangeTblEntry *rte)
* the query is a temporary relation (table, view, or materialized view).
*/
bool
-isQueryUsingTempRelation(Query *query)
+isQueryUsingTempObject(Query *query)
{
- return isQueryUsingTempRelation_walker((Node *) query, NULL);
+ return isQueryUsingTempObject_walker((Node *) query, NULL);
}
static bool
-isQueryUsingTempRelation_walker(Node *node, void *context)
+isQueryUsingTempObject_walker(Node *node, void *context)
{
if (node == NULL)
return false;
@@ -3959,13 +3959,23 @@ isQueryUsingTempRelation_walker(Node *node, void *context)
}
return query_tree_walker(query,
- isQueryUsingTempRelation_walker,
+ isQueryUsingTempObject_walker,
context,
QTW_IGNORE_JOINALIASES);
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ if (isAnyTempNamespace(get_session_variable_namespace(p->paramvarid)))
+ return true;
+ }
+ }
return expression_tree_walker(node,
- isQueryUsingTempRelation_walker,
+ isQueryUsingTempObject_walker,
context);
}
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 783cbb9cd11..50ddcc24140 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5351,12 +5351,16 @@ listVariables(const char *pattern, bool verbose)
" pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n"
" (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
" WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
- " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n",
+ " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
+ " CASE v.varxactendaction\n"
+ " WHEN 'd' THEN 'ON COMMIT DROP'\n"
+ " END as \"%s\"\n",
gettext_noop("Schema"),
gettext_noop("Name"),
gettext_noop("Type"),
gettext_noop("Collation"),
- gettext_noop("Owner"));
+ gettext_noop("Owner"),
+ gettext_noop("Transactional end action"));
if (verbose)
{
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 681fdeb8ee2..e151eaa7498 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -3637,7 +3637,7 @@ match_previous_words(int pattern_id,
/* CREATE TABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete "CREATE TEMP/TEMPORARY" with the possible temp objects */
else if (TailMatches("CREATE", "TEMP|TEMPORARY"))
- COMPLETE_WITH("SEQUENCE", "TABLE", "VIEW");
+ COMPLETE_WITH("SEQUENCE", "TABLE", "VARIABLE", "VIEW");
/* Complete "CREATE UNLOGGED" with TABLE or SEQUENCE */
else if (TailMatches("CREATE", "UNLOGGED"))
COMPLETE_WITH("TABLE", "SEQUENCE");
@@ -3988,7 +3988,8 @@ match_previous_words(int pattern_id,
}
/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE VARIABLE <name> with AS */
- else if (TailMatches("CREATE", "VARIABLE", MatchAny))
+ else if (TailMatches("CREATE", "VARIABLE", MatchAny) ||
+ TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny))
COMPLETE_WITH("AS");
else if (TailMatches("VARIABLE", MatchAny, "AS"))
/* Complete CREATE VARIABLE <name> with AS types */
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 5b45be5afaf..0fc672bc2ba 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -56,6 +56,9 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* typmod for variable's type */
int32 vartypmod BKI_DEFAULT(-1);
+ /* action on transaction end */
+ char varxactendaction BKI_DEFAULT(n);
+
/* variable collation */
Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation);
@@ -68,6 +71,12 @@ CATALOG(pg_variable,9222,VariableRelationId)
#endif
} FormData_pg_variable;
+typedef enum VariableXactEndAction
+{
+ VARIABLE_XACTEND_NOOP = 'n', /* NOOP */
+ VARIABLE_XACTEND_DROP = 'd', /* ON COMMIT DROP */
+} VariableXactEndAction;
+
/* ----------------
* Form_pg_variable corresponds to a pointer to a tuple with
* the format of the pg_variable relation.
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index d3cc79b5608..4492bee6d69 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -21,7 +21,11 @@
#include "tcop/cmdtag.h"
#include "utils/queryenvironment.h"
-extern void SessionVariableDropPostprocess(Oid varid);
+extern void SessionVariableCreatePostprocess(Oid varid, char XactEndAction);
+extern void SessionVariableDropPostprocess(Oid varid, char XactEndAction);
+extern void AtPreEOXact_SessionVariables(bool isCommit);
+extern void AtEOSubXact_SessionVariables(bool isCommit, SubTransactionId mySubid,
+ SubTransactionId parentSubid);
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 6327dba3b71..2e4d9ab5f47 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3546,6 +3546,7 @@ typedef struct CreateSessionVarStmt
TypeName *typeName; /* the type of variable */
CollateClause *collClause;
bool if_not_exists; /* do nothing if it already exists */
+ char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index be63a8d0645..aeed6362484 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -52,7 +52,9 @@ typedef struct Alias
List *colnames; /* optional list of column aliases */
} Alias;
-/* What to do at commit time for temporary relations */
+/*
+ * What to do at commit time for temporary relations or session variables.
+ */
typedef enum OnCommitAction
{
ONCOMMIT_NOOP, /* No ON COMMIT clause (do nothing) */
diff --git a/src/include/parser/parse_relation.h b/src/include/parser/parse_relation.h
index 3ece5cd4eef..3529bfa5b30 100644
--- a/src/include/parser/parse_relation.h
+++ b/src/include/parser/parse_relation.h
@@ -127,6 +127,6 @@ extern int attnameAttNum(Relation rd, const char *attname, bool sysColOK);
extern const NameData *attnumAttName(Relation rd, int attid);
extern Oid attnumTypeId(Relation rd, int attid);
extern Oid attnumCollationId(Relation rd, int attid);
-extern bool isQueryUsingTempRelation(Query *query);
+extern bool isQueryUsingTempObject(Query *query);
#endif /* PARSE_RELATION_H */
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
index 0a5579dc7ce..a609797dc5d 100644
--- a/src/test/isolation/expected/session-variable.out
+++ b/src/test/isolation/expected/session-variable.out
@@ -86,10 +86,11 @@ myvar
step sr1: ROLLBACK;
-starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+starting permutation: create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
step create3: CREATE VARIABLE myvar3 AS text;
step let3: LET myvar3 = 'test';
step s3: BEGIN;
+step o_c_d: CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP;
step create4: CREATE VARIABLE myvar4 AS text;
step let4: LET myvar4 = 'test';
step drop4: DROP VARIABLE myvar4;
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
index c864fee4006..45e65d4085d 100644
--- a/src/test/isolation/specs/session-variable.spec
+++ b/src/test/isolation/specs/session-variable.spec
@@ -24,6 +24,7 @@ step create { CREATE VARIABLE myvar AS text; }
session s3
step s3 { BEGIN; }
step let3 { LET myvar3 = 'test'; }
+step o_c_d { CREATE TEMP VARIABLE myvar_o_c_d AS text ON COMMIT DROP; }
step create4 { CREATE VARIABLE myvar4 AS text; }
step let4 { LET myvar4 = 'test'; }
step drop4 { DROP VARIABLE myvar4; }
@@ -47,4 +48,4 @@ permutation let val dbg drop create dbg val
# calling the dbg step after the concurrent drop
permutation let val s1 dbg drop create dbg val sr1
# test for DISCARD ALL when all internal queues have actions registered
-permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+permutation create3 let3 s3 o_c_d create4 let4 drop4 drop3 inval3 discard sc3 state
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 65d8847e60a..fd3f1243fc3 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6026,20 +6026,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Access privileges | Description
---------+------+-------------------+-----------+------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Access privileges | Description
---------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6507,9 +6507,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner
---------+------+------+-----------+-------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action
+--------+------+------+-----------+-------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6682,9 +6682,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner
---------+------+------+-----------+-------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action
+--------+------+------+-----------+-------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6821,9 +6821,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner
---------+------+------+-----------+-------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Transactional end action
+--------+------+------+-----------+-------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7c63ceef2e5..e4297809ea6 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2145,3 +2145,123 @@ SELECT var1;
DEALLOCATE p1;
DROP VARIABLE var1;
+-- temporary variables
+CREATE TEMP VARIABLE var1 AS int;
+-- this view should be temporary
+CREATE VIEW var_test_view AS SELECT var1;
+NOTICE: view "var_test_view" will be a temporary view
+DROP VARIABLE var1 CASCADE;
+NOTICE: drop cascades to view var_test_view
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+ROLLBACK;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ ROLLBACK TO s1;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+ count
+-------
+ 0
+(1 row)
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 18b59fc9cad..e6ccc37153d 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1312,6 +1312,7 @@ BEGIN;
DROP VARIABLE var1;
SELECT var2;
ROLLBACK;
+
-- should be ok
SELECT var1;
@@ -1479,3 +1480,68 @@ SELECT var1;
DEALLOCATE p1;
DROP VARIABLE var1;
+
+-- temporary variables
+CREATE TEMP VARIABLE var1 AS int;
+-- this view should be temporary
+CREATE VIEW var_test_view AS SELECT var1;
+
+DROP VARIABLE var1 CASCADE;
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SELECT var1;
+ROLLBACK;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ DROP VARIABLE var1;
+ROLLBACK;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
+
+BEGIN;
+ CREATE TEMP VARIABLE var1 AS int ON COMMIT DROP;
+ LET var1 = 100;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ ROLLBACK TO s1;
+ SELECT var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_variable WHERE varname = 'var1';
+-- should be zero
+SELECT count(*) FROM pg_session_variables();
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 05699203b36..f1322734897 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2835,6 +2835,7 @@ SupportRequestWFuncMonotonic
SVariable
SVariableData
SVariableState
+SVariableXActDropItem
Syn
SyncOps
SyncRepConfigData
--
2.48.1
[text/x-patch] v20250301-0015-allow-read-an-value-of-session-variable-directly-fro.patch (15.1K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/17-v20250301-0015-allow-read-an-value-of-session-variable-directly-fro.patch)
download | inline diff:
From adb51bff7f4ee5c79567a39861f45fe926f966dc Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:07:03 +0100
Subject: [PATCH 15/21] allow read an value of session variable directly from
expression executor
The expression executor can be called directly (not inside query executor)
when expression is evaluated as simple expression in plpgsql or when expression
is an argument of CALL or EXECUTE statements. For these cases we need to allow direct
access to content of session variables from executor. We can do it, because
we know so the expression is not evaluated under query and cannot be
evaluated inside parallel worker.
This patch enables session variables for simple expression evaluation.
This patch enables usage session variables in arguments of CALL stmt.
---
src/backend/commands/prepare.c | 10 ---
src/backend/executor/execExpr.c | 86 +++++++++++++++----
src/backend/executor/execExprInterp.c | 14 +++
src/backend/jit/llvm/llvmjit_expr.c | 6 ++
src/backend/parser/analyze.c | 10 ---
src/include/executor/execExpr.h | 11 ++-
.../src/expected/plpgsql_session_variable.out | 3 +-
src/pl/plpgsql/src/pl_exec.c | 3 +-
.../regress/expected/session_variables.out | 38 ++++----
src/test/regress/sql/session_variables.sql | 12 +--
10 files changed, 125 insertions(+), 68 deletions(-)
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 13d198f1625..bb49d8ec665 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -340,16 +340,6 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
i++;
}
- /*
- * The arguments of EXECUTE are evaluated by a direct expression
- * executor call. This mode doesn't support session variables yet.
- * It will be enabled later.
- */
- if (pstate->p_hasSessionVariables)
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("session variable cannot be used as an argument")));
-
/* Prepare the expressions for execution */
exprstates = ExecPrepareExprList(params, estate);
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 270e6d344be..d07377948a0 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -34,6 +34,8 @@
#include "catalog/objectaccess.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
#include "executor/execExpr.h"
#include "executor/nodeSubplan.h"
#include "funcapi.h"
@@ -1054,22 +1056,74 @@ ExecInitExprRec(Expr *node, ExprState *state,
es_num_session_variables = state->parent->state->es_num_session_variables;
}
- Assert(es_session_variables);
-
- /* parameter sanity checks */
- if (param->paramid >= es_num_session_variables)
- elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
-
- var = &es_session_variables[param->paramid];
-
- /*
- * In this case, pass the value like a
- * constant.
- */
- scratch.opcode = EEOP_CONST;
- scratch.d.constval.value = var->value;
- scratch.d.constval.isnull = var->isnull;
- ExprEvalPushStep(state, &scratch);
+ if (es_session_variables)
+ {
+ /*
+ * This path is used when expression is
+ * evaluated inside query evaluation. For
+ * ensuring of immutability of session variable
+ * inside query we use special buffer with copy
+ * of used session variables. This method helps
+ * with parallel execution too.
+ */
+
+ /* parameter sanity checks */
+ if (param->paramid >= es_num_session_variables)
+ elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
+
+ var = &es_session_variables[param->paramid];
+
+ /*
+ * In this case, pass the value like a
+ * constant.
+ */
+ scratch.opcode = EEOP_CONST;
+ scratch.d.constval.value = var->value;
+ scratch.d.constval.isnull = var->isnull;
+ ExprEvalPushStep(state, &scratch);
+ }
+ else
+ {
+ Oid varid = param->paramvarid;
+
+ Assert(!IsParallelWorker());
+
+ /*
+ * In some cases (plpgsql's simple expression
+ * evaluation or evaluation of CALL arguments),
+ * the expression executor is called directly.
+ * We can allow direct access to session
+ * variables (copy only), because we know, so
+ * outside is not any query (and expression
+ * cannot be executed parallel).
+ *
+ * In this case we should to do aclcheck,
+ * because usual aclcheck from
+ * standard_ExecutorStart is not executed in
+ * this case. Fortunately it is just once per
+ * transaction.
+ *
+ * Don't do permission check, when variable is
+ * used like base node for assignment indirection.
+ */
+ if (!param->parambasenode)
+ {
+ AclResult aclresult;
+
+ aclresult = object_aclcheck(
+ VariableRelationId, varid,
+ GetUserId(), ACL_SELECT);
+
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult,
+ OBJECT_VARIABLE,
+ get_session_variable_name(varid));
+ }
+
+ scratch.opcode = EEOP_PARAM_VARIABLE;
+ scratch.d.vparam.varid = varid;
+ ExprEvalPushStep(state, &scratch);
+ }
}
break;
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 1c3477b03c9..45ec7b58610 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -59,6 +59,7 @@
#include "access/heaptoast.h"
#include "catalog/pg_type.h"
#include "commands/sequence.h"
+#include "commands/session_variable.h"
#include "executor/execExpr.h"
#include "executor/nodeSubplan.h"
#include "funcapi.h"
@@ -521,6 +522,7 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
&&CASE_EEOP_PARAM_EXEC,
&&CASE_EEOP_PARAM_EXTERN,
&&CASE_EEOP_PARAM_CALLBACK,
+ &&CASE_EEOP_PARAM_VARIABLE,
&&CASE_EEOP_PARAM_SET,
&&CASE_EEOP_CASE_TESTVAL,
&&CASE_EEOP_CASE_TESTVAL_EXT,
@@ -1265,6 +1267,18 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
EEO_NEXT();
}
+ EEO_CASE(EEOP_PARAM_VARIABLE)
+ {
+ /*
+ * Direct access to session variable (without buffering). Because
+ * returned value can be used (without an assignement) after the
+ * referenced session variables is updated, we have to use an copy
+ * of stored value every time.
+ */
+ *op->resvalue = GetSessionVariable(op->d.vparam.varid, op->resnull);
+ EEO_NEXT();
+ }
+
EEO_CASE(EEOP_PARAM_SET)
{
/* out of line, unlikely to matter performance-wise */
diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c
index f0f5c3bd49f..ad8d80cf49c 100644
--- a/src/backend/jit/llvm/llvmjit_expr.c
+++ b/src/backend/jit/llvm/llvmjit_expr.c
@@ -1208,6 +1208,12 @@ llvm_compile_expr(ExprState *state)
break;
}
+ case EEOP_PARAM_VARIABLE:
+ build_EvalXFunc(b, mod, "ExecEvalParamVariable",
+ v_state, op, v_econtext);
+ LLVMBuildBr(b, opblocks[opno + 1]);
+ break;
+
case EEOP_PARAM_SET:
build_EvalXFunc(b, mod, "ExecEvalParamSet",
v_state, op, v_econtext);
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index c0c3abd7a0e..46a22ff5c94 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -3571,16 +3571,6 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt)
true,
stmt->funccall->location);
- /*
- * The arguments of CALL statement are evaluated by a direct expression
- * executor call. This path is unsupported yet, so block it. It will be
- * enabled later.
- */
- if (pstate->p_hasSessionVariables)
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("session variable cannot be used as an argument")));
-
assign_expr_collations(pstate, node);
fexpr = castNode(FuncExpr, node);
diff --git a/src/include/executor/execExpr.h b/src/include/executor/execExpr.h
index 191d8fe34de..1259ef72bac 100644
--- a/src/include/executor/execExpr.h
+++ b/src/include/executor/execExpr.h
@@ -164,10 +164,11 @@ typedef enum ExprEvalOp
EEOP_BOOLTEST_IS_FALSE,
EEOP_BOOLTEST_IS_NOT_FALSE,
- /* evaluate PARAM_EXEC/EXTERN parameters */
+ /* evaluate PARAM_EXEC/EXTERN/VARIABLE parameters */
EEOP_PARAM_EXEC,
EEOP_PARAM_EXTERN,
EEOP_PARAM_CALLBACK,
+ EEOP_PARAM_VARIABLE,
/* set PARAM_EXEC value */
EEOP_PARAM_SET,
@@ -430,6 +431,12 @@ typedef struct ExprEvalStep
Oid paramtype; /* OID of parameter's datatype */
} cparam;
+ /* for EEOP_PARAM_VARIABLE */
+ struct
+ {
+ Oid varid; /* OID of assigned variable */
+ } vparam;
+
/* for EEOP_CASE_TESTVAL/DOMAIN_TESTVAL */
struct
{
@@ -852,6 +859,8 @@ extern void ExecEvalParamSet(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalParamExtern(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
+extern void ExecEvalParamVariable(ExprState *state, ExprEvalStep *op,
+ ExprContext *econtext);
extern void ExecEvalCoerceViaIOSafe(ExprState *state, ExprEvalStep *op);
extern void ExecEvalSQLValueFunction(ExprState *state, ExprEvalStep *op);
extern void ExecEvalCurrentOfExpr(ExprState *state, ExprEvalStep *op);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index a6523f7afe2..ecac64fcfb4 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -211,8 +211,7 @@ SET ROLE TO regress_var_exec_role;
-- should fail
SELECT var_read_func();
ERROR: permission denied for session variable plpgsql_sv_var1
-CONTEXT: PL/pgSQL expression "plpgsql_sv_var1"
-PL/pgSQL function var_read_func() line 3 at RAISE
+CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE
SET ROLE TO DEFAULT;
SET ROLE TO regress_var_owner_role;
GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index cb282404c1a..d4377ceecbf 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8264,8 +8264,7 @@ exec_is_simple_query(PLpgSQL_expr *expr)
query->sortClause ||
query->limitOffset ||
query->limitCount ||
- query->setOperations ||
- query->hasSessionVariables)
+ query->setOperations)
return false;
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index ba33d366091..98fde7b2595 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -483,8 +483,7 @@ ERROR: permission denied for session variable var1
CONTEXT: SQL function "sqlfx" statement 1
SELECT plpgsqlfx(20);
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "$1 + var1"
-PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
+CONTEXT: PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
-- should be ok
SELECT sqlfx_sd(20);
sqlfx_sd
@@ -780,27 +779,28 @@ $$;
NOTICE: result array: {1,2,3,4,5,6,7,8,9,10}
DROP VARIABLE var1;
DROP VARIABLE var2;
--- CALL statement is not supported yet
--- requires direct access to session variable from expression executor
+-- CALL statement is supported
CREATE VARIABLE v int;
+LET v = 1;
CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
--- should not crash (but is not supported yet)
+-- should to work
CALL p(v);
-ERROR: session variable cannot be used as an argument
+NOTICE: 1
DO $$ BEGIN CALL p(v); END $$;
-ERROR: session variable cannot be used as an argument
-CONTEXT: SQL statement "CALL p(v)"
-PL/pgSQL function inline_code_block line 1 at CALL
+NOTICE: 1
DROP PROCEDURE p(int);
DROP VARIABLE v;
--- EXECUTE statement is not supported yet
--- requires direct access to session variable from expression executor
+-- EXECUTE statement
CREATE VARIABLE v int;
LET v = 20;
PREPARE ptest(int) AS SELECT $1;
--- should fail
+-- should be ok
EXECUTE ptest(v);
-ERROR: session variable cannot be used as an argument
+ ?column?
+----------
+ 20
+(1 row)
+
DEALLOCATE ptest;
DROP VARIABLE v;
-- test search path
@@ -1123,12 +1123,10 @@ LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a
ERROR: permission denied for session variable var1
DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1.a"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
CONTEXT: SQL statement "LET var1.a = var1.a + 10"
@@ -1170,12 +1168,10 @@ LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a
ERROR: permission denied for session variable var1
DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: PL/pgSQL expression "var1.a"
-PL/pgSQL function inline_code_block line 1 at RAISE
+CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
CONTEXT: SQL statement "LET var1.a = var1.a + 10"
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 282ba5c8639..c8c2295adbd 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -548,13 +548,14 @@ $$;
DROP VARIABLE var1;
DROP VARIABLE var2;
--- CALL statement is not supported yet
--- requires direct access to session variable from expression executor
+-- CALL statement is supported
CREATE VARIABLE v int;
+LET v = 1;
+
CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
--- should not crash (but is not supported yet)
+-- should to work
CALL p(v);
DO $$ BEGIN CALL p(v); END $$;
@@ -562,13 +563,12 @@ DO $$ BEGIN CALL p(v); END $$;
DROP PROCEDURE p(int);
DROP VARIABLE v;
--- EXECUTE statement is not supported yet
--- requires direct access to session variable from expression executor
+-- EXECUTE statement
CREATE VARIABLE v int;
LET v = 20;
PREPARE ptest(int) AS SELECT $1;
--- should fail
+-- should be ok
EXECUTE ptest(v);
DEALLOCATE ptest;
--
2.48.1
[text/x-patch] v20250301-0016-allow-parallel-execution-queries-with-session-variab.patch (15.8K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/18-v20250301-0016-allow-parallel-execution-queries-with-session-variab.patch)
download | inline diff:
From 2d233f21323a1ae4a0f263232b3cc8faa5f43386 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:08:17 +0100
Subject: [PATCH 16/21] allow parallel execution queries with session variables
---
doc/src/sgml/parallel.sgml | 6 -
src/backend/commands/session_variable.c | 23 +++
src/backend/executor/execMain.c | 20 ++-
src/backend/executor/execParallel.c | 147 +++++++++++++++++-
src/backend/optimizer/util/clauses.c | 18 +--
src/backend/tcop/pquery.c | 3 +
src/include/commands/session_variable.h | 1 +
src/include/executor/execdesc.h | 4 +
src/include/nodes/execnodes.h | 1 +
.../regress/expected/session_variables.out | 12 +-
10 files changed, 206 insertions(+), 29 deletions(-)
diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index 683dede6adc..1ce9abf86f5 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -515,12 +515,6 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
Plan nodes that reference a correlated <literal>SubPlan</literal>.
</para>
</listitem>
-
- <listitem>
- <para>
- Plan nodes that use a session variable.
- </para>
- </listitem>
</itemizedlist>
<sect2 id="parallel-labeling">
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index 95dd7445c15..bb6abb792be 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -991,6 +991,29 @@ GetSessionVariable(Oid varid, bool *isNull)
return copy_session_variable_value(svar, isNull);
}
+/*
+ * Returns a copy of the value of the session variable (in the current memory
+ * context) plus typid of the session variable. The caller is responsible for
+ * permission checks.
+ */
+Datum
+GetSessionVariableWithTypeid(Oid varid, bool *isNull, Oid *typid)
+{
+ SVariable svar;
+
+ svar = get_session_variable(varid);
+
+ *typid = svar->typid;
+
+ /*
+ * Although "svar" is freshly validated in this point, svar->is_valid can
+ * be false, if an invalidation message was processed during the domain check.
+ * But the variable and all its dependencies are locked now, so we don't need
+ * to repeat the validation.
+ */
+ return copy_session_variable_value(svar, isNull);
+}
+
/*
* Assign the result of the evaluated expression to the session variable
*/
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 67e0b9ba2ac..1feba422bfb 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -220,7 +220,19 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
* be changed inside query execution time, and then a reference to
* previously returned value can be corrupted).
*/
- if (queryDesc->plannedstmt->sessionVariables)
+ if (queryDesc->num_session_variables > 0)
+ {
+ /*
+ * When a parallel query needs to access query parameters (including
+ * related session variables), then related session variables are
+ * restored (deserialized) in queryDesc already. So just push pointer
+ * of this array to executor's estate.
+ */
+ Assert(IsParallelWorker());
+ estate->es_session_variables = queryDesc->session_variables;
+ estate->es_num_session_variables = queryDesc->num_session_variables;
+ }
+ else if (queryDesc->plannedstmt->sessionVariables)
{
int nSessionVariables;
int i = 0;
@@ -259,9 +271,9 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
get_session_variable_name(varid));
}
- estate->es_session_variables[i].value =
- GetSessionVariable(varid,
- &estate->es_session_variables[i].isnull);
+ estate->es_session_variables[i].value = GetSessionVariableWithTypeid(varid,
+ &estate->es_session_variables[i].isnull,
+ &estate->es_session_variables[i].typid);
i++;
}
diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c
index 1bedb808368..aee66beac91 100644
--- a/src/backend/executor/execParallel.c
+++ b/src/backend/executor/execParallel.c
@@ -12,8 +12,9 @@
* workers and ensuring that their state generally matches that of the
* leader; see src/backend/access/transam/README.parallel for details.
* However, we must save and restore relevant executor state, such as
- * any ParamListInfo associated with the query, buffer/WAL usage info, and
- * the actual plan to be passed down to the worker.
+ * any ParamListInfo associated with the query, buffer/WAL usage info,
+ * session variables buffer, and the actual plan to be passed down to
+ * the worker.
*
* IDENTIFICATION
* src/backend/executor/execParallel.c
@@ -64,6 +65,7 @@
#define PARALLEL_KEY_QUERY_TEXT UINT64CONST(0xE000000000000008)
#define PARALLEL_KEY_JIT_INSTRUMENTATION UINT64CONST(0xE000000000000009)
#define PARALLEL_KEY_WAL_USAGE UINT64CONST(0xE00000000000000A)
+#define PARALLEL_KEY_SESSION_VARIABLES UINT64CONST(0xE00000000000000B)
#define PARALLEL_TUPLE_QUEUE_SIZE 65536
@@ -138,6 +140,12 @@ static bool ExecParallelRetrieveInstrumentation(PlanState *planstate,
/* Helper function that runs in the parallel worker. */
static DestReceiver *ExecParallelGetReceiver(dsm_segment *seg, shm_toc *toc);
+/* Helper functions that can pass values of session variables */
+static Size EstimateSessionVariables(EState *estate);
+static void SerializeSessionVariables(EState *estate, char **start_address);
+static SessionVariableValue *RestoreSessionVariables(char **start_address,
+ int *num_session_variables);
+
/*
* Create a serialized representation of the plan to be sent to each worker.
*/
@@ -598,6 +606,7 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
char *pstmt_data;
char *pstmt_space;
char *paramlistinfo_space;
+ char *session_variables_space;
BufferUsage *bufusage_space;
WalUsage *walusage_space;
SharedExecutorInstrumentation *instrumentation = NULL;
@@ -607,6 +616,7 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
int instrumentation_len = 0;
int jit_instrumentation_len = 0;
int instrument_offset = 0;
+ int session_variables_len = 0;
Size dsa_minsize = dsa_minimum_size();
char *query_string;
int query_len;
@@ -662,6 +672,11 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
shm_toc_estimate_chunk(&pcxt->estimator, paramlistinfo_len);
shm_toc_estimate_keys(&pcxt->estimator, 1);
+ /* Estimate space for serialized session variables. */
+ session_variables_len = EstimateSessionVariables(estate);
+ shm_toc_estimate_chunk(&pcxt->estimator, session_variables_len);
+ shm_toc_estimate_keys(&pcxt->estimator, 1);
+
/*
* Estimate space for BufferUsage.
*
@@ -763,6 +778,11 @@ ExecInitParallelPlan(PlanState *planstate, EState *estate,
shm_toc_insert(pcxt->toc, PARALLEL_KEY_PARAMLISTINFO, paramlistinfo_space);
SerializeParamList(estate->es_param_list_info, ¶mlistinfo_space);
+ /* Store serialized session variables. */
+ session_variables_space = shm_toc_allocate(pcxt->toc, session_variables_len);
+ shm_toc_insert(pcxt->toc, PARALLEL_KEY_SESSION_VARIABLES, session_variables_space);
+ SerializeSessionVariables(estate, &session_variables_space);
+
/* Allocate space for each worker's BufferUsage; no need to initialize. */
bufusage_space = shm_toc_allocate(pcxt->toc,
mul_size(sizeof(BufferUsage), pcxt->nworkers));
@@ -1420,6 +1440,7 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
SharedJitInstrumentation *jit_instrumentation;
int instrument_options = 0;
void *area_space;
+ char *sessionvariable_space;
dsa_area *area;
ParallelWorkerContext pwcxt;
@@ -1445,6 +1466,14 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
area_space = shm_toc_lookup(toc, PARALLEL_KEY_DSA, false);
area = dsa_attach_in_place(area_space, seg);
+ /* Reconstruct session variables. */
+ sessionvariable_space = shm_toc_lookup(toc,
+ PARALLEL_KEY_SESSION_VARIABLES,
+ false);
+ queryDesc->session_variables =
+ RestoreSessionVariables(&sessionvariable_space,
+ &queryDesc->num_session_variables);
+
/* Start up the executor */
queryDesc->plannedstmt->jitFlags = fpes->jit_flags;
if (!ExecutorStart(queryDesc, fpes->eflags))
@@ -1513,3 +1542,117 @@ ParallelQueryMain(dsm_segment *seg, shm_toc *toc)
FreeQueryDesc(queryDesc);
receiver->rDestroy(receiver);
}
+
+/*
+ * Estimate the amount of space required to serialize a session variable.
+ */
+static Size
+EstimateSessionVariables(EState *estate)
+{
+ int i;
+ Size sz = sizeof(int);
+
+ if (estate->es_session_variables == NULL)
+ return sz;
+
+ for (i = 0; i < estate->es_num_session_variables; i++)
+ {
+ SessionVariableValue *svarval;
+ Oid typeOid;
+ int16 typLen;
+ bool typByVal;
+
+ svarval = &estate->es_session_variables[i];
+
+ typeOid = svarval->typid;
+
+ sz = add_size(sz, sizeof(Oid)); /* space for type OID */
+
+ /* space for datum/isnull */
+ Assert(OidIsValid(typeOid));
+ get_typlenbyval(typeOid, &typLen, &typByVal);
+
+ sz = add_size(sz,
+ datumEstimateSpace(svarval->value, svarval->isnull, typByVal, typLen));
+ }
+
+ return sz;
+}
+
+/*
+ * Serialize a session variables buffer into caller-provided storage.
+ *
+ * We write the number of parameters first, as a 4-byte integer, and then
+ * write details for each parameter in turn. The details for each parameter
+ * consist of a 4-byte type OID, and then the datum as serialized by
+ * datumSerialize(). The caller is responsible for ensuring that there is
+ * enough storage to store the number of bytes that will be written; use
+ * EstimateSessionVariables to find out how many will be needed.
+ * *start_address is updated to point to the byte immediately following those
+ * written.
+ *
+ * RestoreSessionVariables can be used to recreate a session variable buffer
+ * based on the serialized representation;
+ */
+static void
+SerializeSessionVariables(EState *estate, char **start_address)
+{
+ int nparams;
+ int i;
+
+ /* Write number of parameters. */
+ nparams = estate->es_num_session_variables;
+ memcpy(*start_address, &nparams, sizeof(int));
+ *start_address += sizeof(int);
+
+ /* Write each parameter in turn. */
+ for (i = 0; i < nparams; i++)
+ {
+ SessionVariableValue *svarval;
+ Oid typeOid;
+ int16 typLen;
+ bool typByVal;
+
+ svarval = &estate->es_session_variables[i];
+ typeOid = svarval->typid;
+
+ /* Write type OID. */
+ memcpy(*start_address, &typeOid, sizeof(Oid));
+ *start_address += sizeof(Oid);
+
+ Assert(OidIsValid(typeOid));
+ get_typlenbyval(typeOid, &typLen, &typByVal);
+
+ datumSerialize(svarval->value, svarval->isnull, typByVal, typLen,
+ start_address);
+ }
+}
+
+static SessionVariableValue *
+RestoreSessionVariables(char **start_address, int *num_session_variables)
+{
+ SessionVariableValue *session_variables;
+ int i;
+ int nparams;
+
+ memcpy(&nparams, *start_address, sizeof(int));
+ *start_address += sizeof(int);
+
+ *num_session_variables = nparams;
+ session_variables = (SessionVariableValue *)
+ palloc(nparams * sizeof(SessionVariableValue));
+
+ for (i = 0; i < nparams; i++)
+ {
+ SessionVariableValue *svarval = &session_variables[i];
+
+ /* Read type OID. */
+ memcpy(&svarval->typid, *start_address, sizeof(Oid));
+ *start_address += sizeof(Oid);
+
+ /* Read datum/isnull. */
+ svarval->value = datumRestore(start_address, &svarval->isnull);
+ }
+
+ return session_variables;
+}
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index f60828f862e..175390c6c28 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -923,25 +923,19 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
/*
* We can't pass Params to workers at the moment either, so they are also
- * parallel-restricted, unless they are PARAM_EXTERN Params or are
- * PARAM_EXEC Params listed in safe_param_ids, meaning they could be
- * either generated within workers or can be computed by the leader and
- * then their value can be passed to workers.
+ * parallel-restricted, unless they are PARAM_EXTERN or PARAM_VARIABLE
+ * Params or are PARAM_EXEC Params listed in safe_param_ids, meaning they
+ * could be either generated within workers or can be computed by the
+ * leader and then their value can be passed to workers.
*/
else if (IsA(node, Param))
{
Param *param = (Param *) node;
- if (param->paramkind == PARAM_EXTERN)
+ if (param->paramkind == PARAM_EXTERN ||
+ param->paramkind == PARAM_VARIABLE)
return false;
- /* we don't support passing session variables to workers */
- if (param->paramkind == PARAM_VARIABLE)
- {
- if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
- return true;
- }
-
if (param->paramkind != PARAM_EXEC ||
!list_member_int(context->safe_param_ids, param->paramid))
{
diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c
index dea24453a6c..dce885190c2 100644
--- a/src/backend/tcop/pquery.c
+++ b/src/backend/tcop/pquery.c
@@ -92,6 +92,9 @@ CreateQueryDesc(PlannedStmt *plannedstmt,
qd->queryEnv = queryEnv;
qd->instrument_options = instrument_options; /* instrumentation wanted? */
+ qd->num_session_variables = 0;
+ qd->session_variables = NULL;
+
/* null these fields until set by ExecutorStart */
qd->tupDesc = NULL;
qd->estate = NULL;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index 4492bee6d69..f66b6c0b864 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -29,6 +29,7 @@ extern void AtEOSubXact_SessionVariables(bool isCommit, SubTransactionId mySubid
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
+extern Datum GetSessionVariableWithTypeid(Oid varid, bool *isNull, Oid *typid);
extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
QueryEnvironment *queryEnv, QueryCompletion *qc);
diff --git a/src/include/executor/execdesc.h b/src/include/executor/execdesc.h
index ba53305ad42..41eeb1c83c9 100644
--- a/src/include/executor/execdesc.h
+++ b/src/include/executor/execdesc.h
@@ -52,6 +52,10 @@ typedef struct QueryDesc
/* This field is set by ExecutePlan */
bool already_executed; /* true if previously executed */
+ /* reference to session variables buffer */
+ int num_session_variables;
+ SessionVariableValue *session_variables;
+
/* This is always set NULL by the core system, but plugins can change it */
struct Instrumentation *totaltime; /* total time spent in ExecutorRun */
} QueryDesc;
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 1b8ad640922..5632f77aee7 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -642,6 +642,7 @@ typedef struct AsyncRequest
*/
typedef struct SessionVariableValue
{
+ Oid typid;
bool isnull;
Datum value;
} SessionVariableValue;
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 98fde7b2595..57cdd296a7c 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1284,12 +1284,14 @@ SELECT count(*) FROM svar_test WHERE a%10 = zero;
-- parallel execution is not supported yet
EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
- QUERY PLAN
------------------------------------
+ QUERY PLAN
+--------------------------------------------
Aggregate
- -> Seq Scan on svar_test
- Filter: ((a % 10) = zero)
-(3 rows)
+ -> Gather
+ Workers Planned: 2
+ -> Parallel Seq Scan on svar_test
+ Filter: ((a % 10) = zero)
+(5 rows)
LET zero = (SELECT count(*) FROM svar_test);
-- result should be 1000
--
2.48.1
[text/x-patch] v20250301-0017-plpgsql-implementation-for-LET-statement.patch (16.8K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/19-v20250301-0017-plpgsql-implementation-for-LET-statement.patch)
download | inline diff:
From 579a8eec54ed55ccc7e8eab7764aa6b79a3a8da8 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sat, 20 Jan 2024 08:56:17 +0100
Subject: [PATCH 17/21] plpgsql implementation for LET statement
PLpgSQL allows to call expression executor directly (for simple expression).
This possibility strongly reduces overhead related to execution. Reimplementation
of LET statement (inside PLpgSQL) allows to use this possibility, and strongly
increase performance:
CREATE VARIABLE svar int;
DO $$
BEGIN
FOR i IN 1..10000
LOOP
LET svar = i;
END LOOP;
END;
$$;
From 120ms to 8ms (with assertions) (this is best case, but without it, the LET statement
can be bottle neck).
An alternative can be reimplementation of LET statement inside expression
executor, and then SQL LET command can be executed in simple expression
execution, but this increase an complexity of executor, but still the
benefits is only inside plpgsql, so it is better to this optimization
inside plpgsql.
---
src/backend/commands/session_variable.c | 16 ++++++
src/backend/executor/spi.c | 3 +
src/backend/parser/analyze.c | 12 ++++
src/backend/parser/gram.y | 8 +++
src/backend/parser/parser.c | 1 +
src/include/commands/session_variable.h | 1 +
src/include/nodes/parsenodes.h | 2 +
src/include/parser/parser.h | 4 ++
src/pl/plpgsql/src/pl_exec.c | 56 +++++++++++++++++++
src/pl/plpgsql/src/pl_funcs.c | 21 +++++++
src/pl/plpgsql/src/pl_gram.y | 29 +++++++++-
src/pl/plpgsql/src/pl_reserved_kwlist.h | 1 +
src/pl/plpgsql/src/pl_unreserved_kwlist.h | 1 +
src/pl/plpgsql/src/plpgsql.h | 12 ++++
.../regress/expected/session_variables.out | 6 +-
src/tools/pgindent/typedefs.list | 1 +
16 files changed, 169 insertions(+), 5 deletions(-)
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index bb6abb792be..b08c1b47d38 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -948,6 +948,22 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
set_session_variable(svar, value, isNull);
}
+/*
+ * Wrapper around SetSessionVariable with permission checks.
+ */
+void
+SetSessionVariableWithSecurityCheck(Oid varid, Datum value, bool isNull)
+{
+ AclResult aclresult;
+
+ /* is the caller allowed to update the session variable? */
+ aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid));
+
+ SetSessionVariable(varid, value, isNull);
+}
+
/*
* Returns a copy of the value stored in a variable.
*/
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 3288396def3..e3c4d259d53 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -3008,6 +3008,9 @@ _SPI_error_callback(void *arg)
case RAW_PARSE_PLPGSQL_ASSIGN3:
errcontext("PL/pgSQL assignment \"%s\"", query);
break;
+ case RAW_PARSE_PLPGSQL_LET:
+ errcontext("LET statement \"%s\"", query);
+ break;
default:
errcontext("SQL statement \"%s\"", query);
break;
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 46a22ff5c94..2de0d23c8e3 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -2012,6 +2012,18 @@ transformLetStmt(ParseState *pstate, LetStmt *stmt)
stmt->query = (Node *) query;
+ /*
+ * Inside PL/pgSQL we don't want to execute LET statement as utility
+ * command, because it disallow to execute expression as simple
+ * expression. So for PL/pgSQL we have extra path, and we return SELECT.
+ * Then it can be executed by exec_eval_expr. Result is dirrectly assigned
+ * to target session variable inside PL/pgSQL LET statement handler. This
+ * is extra code, extra path, but possibility to get faster execution is
+ * too attractive.
+ */
+ if (stmt->plpgsql_mode)
+ return query;
+
/* represent the command as a utility Query */
result = makeNode(Query);
result->commandType = CMD_UTILITY;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 53284c0289c..1c96bbf0819 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -824,6 +824,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%token MODE_PLPGSQL_ASSIGN1
%token MODE_PLPGSQL_ASSIGN2
%token MODE_PLPGSQL_ASSIGN3
+%token MODE_PLPGSQL_LET
/* Precedence: lowest to highest */
@@ -955,6 +956,13 @@ parse_toplevel:
pg_yyget_extra(yyscanner)->parsetree =
list_make1(makeRawStmt((Node *) n, @2));
}
+ | MODE_PLPGSQL_LET LetStmt
+ {
+ LetStmt *n = (LetStmt *) $2;
+ n->plpgsql_mode = true;
+ pg_yyget_extra(yyscanner)->parsetree =
+ list_make1(makeRawStmt((Node *) n, 0));
+ }
;
/*
diff --git a/src/backend/parser/parser.c b/src/backend/parser/parser.c
index 33a040506b4..887212aefde 100644
--- a/src/backend/parser/parser.c
+++ b/src/backend/parser/parser.c
@@ -62,6 +62,7 @@ raw_parser(const char *str, RawParseMode mode)
[RAW_PARSE_PLPGSQL_ASSIGN1] = MODE_PLPGSQL_ASSIGN1,
[RAW_PARSE_PLPGSQL_ASSIGN2] = MODE_PLPGSQL_ASSIGN2,
[RAW_PARSE_PLPGSQL_ASSIGN3] = MODE_PLPGSQL_ASSIGN3,
+ [RAW_PARSE_PLPGSQL_LET] = MODE_PLPGSQL_LET,
};
yyextra.have_lookahead = true;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index f66b6c0b864..b89728ead5a 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -28,6 +28,7 @@ extern void AtEOSubXact_SessionVariables(bool isCommit, SubTransactionId mySubid
SubTransactionId parentSubid);
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
+extern void SetSessionVariableWithSecurityCheck(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
extern Datum GetSessionVariableWithTypeid(Oid varid, bool *isNull, Oid *typid);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 785354ab52c..8d0d7cf6ec9 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2168,6 +2168,8 @@ typedef struct LetStmt
NodeTag type;
List *target; /* target variable */
Node *query; /* source expression */
+ bool plpgsql_mode; /* true, when command will be executed
+ * (parsed) by plpgsql runtime */
ParseLoc location;
} LetStmt;
diff --git a/src/include/parser/parser.h b/src/include/parser/parser.h
index 350196cd641..c8d5e8dbf92 100644
--- a/src/include/parser/parser.h
+++ b/src/include/parser/parser.h
@@ -33,6 +33,9 @@
* RAW_PARSE_PLPGSQL_ASSIGNn: parse a PL/pgSQL assignment statement,
* and return a one-element List containing a RawStmt node. "n"
* gives the number of dotted names comprising the target ColumnRef.
+ *
+ * RAW_PARSE_PLPGSQL_LET: parse a LET statement, and return a
+ * one-element List containing a RawStmt node.
*/
typedef enum
{
@@ -42,6 +45,7 @@ typedef enum
RAW_PARSE_PLPGSQL_ASSIGN1,
RAW_PARSE_PLPGSQL_ASSIGN2,
RAW_PARSE_PLPGSQL_ASSIGN3,
+ RAW_PARSE_PLPGSQL_LET,
} RawParseMode;
/* Values for the backslash_quote GUC */
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index d4377ceecbf..05eb4ac4f32 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -22,6 +22,7 @@
#include "access/tupconvert.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "commands/session_variable.h"
#include "executor/execExpr.h"
#include "executor/spi.h"
#include "executor/tstoreReceiver.h"
@@ -333,6 +334,8 @@ static int exec_stmt_commit(PLpgSQL_execstate *estate,
PLpgSQL_stmt_commit *stmt);
static int exec_stmt_rollback(PLpgSQL_execstate *estate,
PLpgSQL_stmt_rollback *stmt);
+static int exec_stmt_let(PLpgSQL_execstate *estate,
+ PLpgSQL_stmt_let *let);
static void plpgsql_estate_setup(PLpgSQL_execstate *estate,
PLpgSQL_function *func,
@@ -2132,6 +2135,10 @@ exec_stmts(PLpgSQL_execstate *estate, List *stmts)
rc = exec_stmt_rollback(estate, (PLpgSQL_stmt_rollback *) stmt);
break;
+ case PLPGSQL_STMT_LET:
+ rc = exec_stmt_let(estate, (PLpgSQL_stmt_let *) stmt);
+ break;
+
default:
/* point err_stmt to parent, since this one seems corrupt */
estate->err_stmt = save_estmt;
@@ -5009,6 +5016,55 @@ exec_stmt_rollback(PLpgSQL_execstate *estate, PLpgSQL_stmt_rollback *stmt)
return PLPGSQL_RC_OK;
}
+/* ----------
+ * exec_stmt_let Evaluate an expression and
+ * put the result into a session variable.
+ * ----------
+ */
+static int
+exec_stmt_let(PLpgSQL_execstate *estate, PLpgSQL_stmt_let *stmt)
+{
+ bool isNull;
+ Oid valtype;
+ int32 valtypmod;
+ Datum value;
+ Oid varid;
+
+ List *plansources;
+ CachedPlanSource *plansource;
+
+ value = exec_eval_expr(estate,
+ stmt->expr,
+ &isNull,
+ &valtype,
+ &valtypmod);
+
+ /*
+ * Oid of target session variable is stored in Query structure. It is
+ * safer to read this value directly from the plan than to hold this value
+ * in the plpgsql context, because it's not necessary to handle
+ * invalidation of the cached value. Next operations are read only without
+ * any allocations, so we can expect that retrieving varid from Query
+ * should be fast.
+ */
+ plansources = SPI_plan_get_plan_sources(stmt->expr->plan);
+ if (list_length(plansources) != 1)
+ elog(ERROR, "unexpected length of plansources of query for LET statement");
+
+ plansource = (CachedPlanSource *) linitial(plansources);
+ if (list_length(plansource->query_list) != 1)
+ elog(ERROR, "unexpected length of plansource of query for LET statement");
+
+ varid = linitial_node(Query, plansource->query_list)->resultVariable;
+ if (!OidIsValid(varid))
+ elog(ERROR, "oid of target session variable is not valid");
+
+ SetSessionVariableWithSecurityCheck(varid, value, isNull);
+ exec_eval_cleanup(estate);
+
+ return PLPGSQL_RC_OK;
+}
+
/* ----------
* exec_assign_expr Put an expression's result into a variable.
* ----------
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index 6b5394fc5fa..242b57f76de 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -288,6 +288,8 @@ plpgsql_stmt_typename(PLpgSQL_stmt *stmt)
return "COMMIT";
case PLPGSQL_STMT_ROLLBACK:
return "ROLLBACK";
+ case PLPGSQL_STMT_LET:
+ return "LET";
}
return "unknown";
@@ -585,6 +587,13 @@ plpgsql_statement_tree_walker_impl(PLpgSQL_stmt *stmt,
E_WALK(cstmt->expr);
break;
}
+ case PLPGSQL_STMT_LET:
+ {
+ PLpgSQL_stmt_let *lstmt = (PLpgSQL_stmt_let *) stmt;
+
+ E_WALK(lstmt->expr);
+ break;
+ }
case PLPGSQL_STMT_COMMIT:
case PLPGSQL_STMT_ROLLBACK:
{
@@ -806,6 +815,7 @@ static void dump_perform(PLpgSQL_stmt_perform *stmt);
static void dump_call(PLpgSQL_stmt_call *stmt);
static void dump_commit(PLpgSQL_stmt_commit *stmt);
static void dump_rollback(PLpgSQL_stmt_rollback *stmt);
+static void dump_let(PLpgSQL_stmt_let *stmt);
static void dump_expr(PLpgSQL_expr *expr);
@@ -905,6 +915,9 @@ dump_stmt(PLpgSQL_stmt *stmt)
case PLPGSQL_STMT_ROLLBACK:
dump_rollback((PLpgSQL_stmt_rollback *) stmt);
break;
+ case PLPGSQL_STMT_LET:
+ dump_let((PLpgSQL_stmt_let *) stmt);
+ break;
default:
elog(ERROR, "unrecognized cmd_type: %d", stmt->cmd_type);
break;
@@ -1581,6 +1594,14 @@ dump_getdiag(PLpgSQL_stmt_getdiag *stmt)
printf("\n");
}
+static void
+dump_let(PLpgSQL_stmt_let *stmt)
+{
+ dump_ind();
+ dump_expr(stmt->expr);
+ printf("\n");
+}
+
static void
dump_expr(PLpgSQL_expr *expr)
{
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index 8048e040f81..980ebb56a45 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -210,7 +210,7 @@ static void check_raise_parameters(PLpgSQL_stmt_raise *stmt);
%type <stmt> stmt_return stmt_raise stmt_assert stmt_execsql
%type <stmt> stmt_dynexecute stmt_for stmt_perform stmt_call stmt_getdiag
%type <stmt> stmt_open stmt_fetch stmt_move stmt_close stmt_null
-%type <stmt> stmt_commit stmt_rollback
+%type <stmt> stmt_commit stmt_rollback stmt_let
%type <stmt> stmt_case stmt_foreach_a
%type <list> proc_exceptions
@@ -317,6 +317,7 @@ static void check_raise_parameters(PLpgSQL_stmt_raise *stmt);
%token <keyword> K_INTO
%token <keyword> K_IS
%token <keyword> K_LAST
+%token <keyword> K_LET
%token <keyword> K_LOG
%token <keyword> K_LOOP
%token <keyword> K_MERGE
@@ -891,6 +892,8 @@ proc_stmt : pl_block ';'
{ $$ = $1; }
| stmt_rollback
{ $$ = $1; }
+ | stmt_let
+ { $$ = $1; }
;
stmt_perform : K_PERFORM
@@ -1010,6 +1013,30 @@ stmt_assign : T_DATUM
}
;
+stmt_let : K_LET
+ {
+ PLpgSQL_stmt_let *new;
+ RawParseMode pmode;
+
+ pmode = RAW_PARSE_PLPGSQL_LET;
+
+ new = palloc0(sizeof(PLpgSQL_stmt_let));
+ new->cmd_type = PLPGSQL_STMT_LET;
+ new->lineno = plpgsql_location_to_lineno(@1, yyscanner);
+ new->stmtid = ++plpgsql_curr_compile->nstatements;
+
+ /* push back the head name to include it in the stmt */
+ plpgsql_push_back_token(K_LET, &yylval, &yylloc, yyscanner);
+ new->expr = read_sql_construct(';', 0, 0, ";",
+ pmode,
+ false, true,
+ NULL, NULL,
+ &yylval, &yylloc, yyscanner);
+
+ $$ = (PLpgSQL_stmt *)new;
+ }
+ ;
+
stmt_getdiag : K_GET getdiag_area_opt K_DIAGNOSTICS getdiag_list ';'
{
PLpgSQL_stmt_getdiag *new;
diff --git a/src/pl/plpgsql/src/pl_reserved_kwlist.h b/src/pl/plpgsql/src/pl_reserved_kwlist.h
index ce7b0c9d331..e266bd1cc46 100644
--- a/src/pl/plpgsql/src/pl_reserved_kwlist.h
+++ b/src/pl/plpgsql/src/pl_reserved_kwlist.h
@@ -40,6 +40,7 @@ PG_KEYWORD("from", K_FROM)
PG_KEYWORD("if", K_IF)
PG_KEYWORD("in", K_IN)
PG_KEYWORD("into", K_INTO)
+PG_KEYWORD("let", K_LET)
PG_KEYWORD("loop", K_LOOP)
PG_KEYWORD("not", K_NOT)
PG_KEYWORD("null", K_NULL)
diff --git a/src/pl/plpgsql/src/pl_unreserved_kwlist.h b/src/pl/plpgsql/src/pl_unreserved_kwlist.h
index 98f99ec470c..ed14fd86c31 100644
--- a/src/pl/plpgsql/src/pl_unreserved_kwlist.h
+++ b/src/pl/plpgsql/src/pl_unreserved_kwlist.h
@@ -69,6 +69,7 @@ PG_KEYWORD("info", K_INFO)
PG_KEYWORD("insert", K_INSERT)
PG_KEYWORD("is", K_IS)
PG_KEYWORD("last", K_LAST)
+PG_KEYWORD("let", K_LET)
PG_KEYWORD("log", K_LOG)
PG_KEYWORD("merge", K_MERGE)
PG_KEYWORD("message", K_MESSAGE)
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index d73996e09c0..c7538612f1a 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -128,6 +128,7 @@ typedef enum PLpgSQL_stmt_type
PLPGSQL_STMT_CALL,
PLPGSQL_STMT_COMMIT,
PLPGSQL_STMT_ROLLBACK,
+ PLPGSQL_STMT_LET,
} PLpgSQL_stmt_type;
/*
@@ -542,6 +543,17 @@ typedef struct PLpgSQL_stmt_assign
PLpgSQL_expr *expr;
} PLpgSQL_stmt_assign;
+/*
+ * Let statement
+ */
+typedef struct PLpgSQL_stmt_let
+{
+ PLpgSQL_stmt_type cmd_type;
+ int lineno;
+ unsigned int stmtid;
+ PLpgSQL_expr *expr;
+} PLpgSQL_stmt_let;
+
/*
* PERFORM statement
*/
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 57cdd296a7c..24dcfed200b 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1129,8 +1129,7 @@ ERROR: permission denied for session variable var1
CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: SQL statement "LET var1.a = var1.a + 10"
-PL/pgSQL function inline_code_block line 1 at SQL statement
+CONTEXT: PL/pgSQL function inline_code_block line 1 at LET
SET ROLE TO DEFAULT;
GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
SET ROLE TO regress_var_test_role;
@@ -1174,8 +1173,7 @@ ERROR: permission denied for session variable var1
CONTEXT: PL/pgSQL function inline_code_block line 1 at RAISE
DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
ERROR: permission denied for session variable var1
-CONTEXT: SQL statement "LET var1.a = var1.a + 10"
-PL/pgSQL function inline_code_block line 1 at SQL statement
+CONTEXT: PL/pgSQL function inline_code_block line 1 at LET
SET ROLE TO DEFAULT;
DROP VARIABLE var1;
DROP TABLE vartesttab;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index f1322734897..15017bb56c5 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1910,6 +1910,7 @@ PLpgSQL_stmt_forq
PLpgSQL_stmt_fors
PLpgSQL_stmt_getdiag
PLpgSQL_stmt_if
+PLpgSQL_stmt_let
PLpgSQL_stmt_loop
PLpgSQL_stmt_open
PLpgSQL_stmt_perform
--
2.48.1
[text/x-patch] v20250301-0018-expression-with-session-variables-can-be-inlined.patch (4.2K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/20-v20250301-0018-expression-with-session-variables-can-be-inlined.patch)
download | inline diff:
From 5c1aca8b27803a73c2ef39cdea82a2c45985a289 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sat, 20 Jan 2024 20:35:38 +0100
Subject: [PATCH 18/21] expression with session variables can be inlined
There is not an reason why session variables should to block inlining.
(of SQL functions). I can imagine some use cases like wrapping, and
inlining significantly reduces an overhead of SQL functions.
---
src/backend/optimizer/util/clauses.c | 37 ++++++++++++++-----
.../regress/expected/session_variables.out | 7 ++--
2 files changed, 30 insertions(+), 14 deletions(-)
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 175390c6c28..0eb52fa2081 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -4744,8 +4744,7 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
querytree->limitOffset ||
querytree->limitCount ||
querytree->setOperations ||
- (list_length(querytree->targetList) != 1) ||
- querytree->hasSessionVariables)
+ (list_length(querytree->targetList) != 1))
goto fail;
/* If the function result is composite, resolve it */
@@ -4949,21 +4948,39 @@ substitute_actual_parameters_mutator(Node *node,
{
if (node == NULL)
return NULL;
+
+
+ /*
+ * SQL functions can contain two different kind of params. The nodes with
+ * paramkind PARAM_EXTERN are related to function's arguments (and should
+ * be replaced in this step), because this is how we apply the function's
+ * arguments for an expression.
+ *
+ * The nodes with paramkind PARAM_VARIABLE are related to usage of session
+ * variables. The values of session variables are not passed to expression
+ * by expression arguments, so it should not be replaced here by
+ * function's arguments.
+ */
if (IsA(node, Param))
{
Param *param = (Param *) node;
- if (param->paramkind != PARAM_EXTERN)
+ if (param->paramkind != PARAM_EXTERN &&
+ param->paramkind != PARAM_VARIABLE)
elog(ERROR, "unexpected paramkind: %d", (int) param->paramkind);
- if (param->paramid <= 0 || param->paramid > context->nargs)
- elog(ERROR, "invalid paramid: %d", param->paramid);
- /* Count usage of parameter */
- context->usecounts[param->paramid - 1]++;
+ if (param->paramkind == PARAM_EXTERN)
+ {
+ if (param->paramid <= 0 || param->paramid > context->nargs)
+ elog(ERROR, "invalid paramid: %d", param->paramid);
- /* Select the appropriate actual arg and replace the Param with it */
- /* We don't need to copy at this time (it'll get done later) */
- return list_nth(context->args, param->paramid - 1);
+ /* Count usage of parameter */
+ context->usecounts[param->paramid - 1]++;
+
+ /* Select the appropriate actual arg and replace the Param with it */
+ /* We don't need to copy at this time (it'll get done later) */
+ return list_nth(context->args, param->paramid - 1);
+ }
}
return expression_tree_mutator(node, substitute_actual_parameters_mutator, context);
}
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 24dcfed200b..e0aa0408f71 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -480,7 +480,6 @@ SELECT var1;
ERROR: permission denied for session variable var1
SELECT sqlfx(20);
ERROR: permission denied for session variable var1
-CONTEXT: SQL function "sqlfx" statement 1
SELECT plpgsqlfx(20);
ERROR: permission denied for session variable var1
CONTEXT: PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
@@ -587,10 +586,10 @@ SELECT sqlfx1(sqlfx2('Hello'));
-- inlining is blocked
EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
- QUERY PLAN
-------------------------------------------------------
+ QUERY PLAN
+-----------------------------------------------------------------------------
Result
- Output: sqlfx1(sqlfx2('Hello'::character varying))
+ Output: ((var1 || ', '::text) || ((var2 || ', '::text) || 'Hello'::text))
(2 rows)
DROP FUNCTION sqlfx1(varchar);
--
2.48.1
[text/x-patch] v20250301-0021-pg_restore-A-variable.patch (2.8K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/21-v20250301-0021-pg_restore-A-variable.patch)
download | inline diff:
From 5497a6bdebd4b5e701ba46433a1b46450e0d314e Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sun, 21 Jul 2024 17:04:41 +0200
Subject: [PATCH 21/21] pg_restore -A, --variable
possibility to restore session variable specified by name
---
doc/src/sgml/ref/pg_restore.sgml | 11 +++++++++++
src/bin/pg_dump/pg_restore.c | 9 ++++++++-
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/doc/src/sgml/ref/pg_restore.sgml b/doc/src/sgml/ref/pg_restore.sgml
index 199ea3345f3..847e51b6276 100644
--- a/doc/src/sgml/ref/pg_restore.sgml
+++ b/doc/src/sgml/ref/pg_restore.sgml
@@ -106,6 +106,17 @@ PostgreSQL documentation
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>-A <replaceable class="parameter">session_variable</replaceable></option></term>
+ <term><option>--variable=<replaceable class="parameter">session_variable</replaceable></option></term>
+ <listitem>
+ <para>
+ Restore a named session variable only. Multiple session variables may
+ be specified with multiple <option>-A</option> switches.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>-c</option></term>
<term><option>--clean</option></term>
diff --git a/src/bin/pg_dump/pg_restore.c b/src/bin/pg_dump/pg_restore.c
index 13e4dc507e0..60f01b23dba 100644
--- a/src/bin/pg_dump/pg_restore.c
+++ b/src/bin/pg_dump/pg_restore.c
@@ -110,6 +110,7 @@ main(int argc, char **argv)
{"trigger", 1, NULL, 'T'},
{"use-list", 1, NULL, 'L'},
{"username", 1, NULL, 'U'},
+ {"variable", 1, NULL, 'A'},
{"verbose", 0, NULL, 'v'},
{"single-transaction", 0, NULL, '1'},
@@ -164,7 +165,7 @@ main(int argc, char **argv)
}
}
- while ((c = getopt_long(argc, argv, "acCd:ef:F:h:I:j:lL:n:N:Op:P:RsS:t:T:U:vwWx1",
+ while ((c = getopt_long(argc, argv, "A:acCd:ef:F:h:I:j:lL:n:N:Op:P:RsS:t:T:U:vwWx1",
cmdopts, NULL)) != -1)
{
switch (c)
@@ -172,6 +173,11 @@ main(int argc, char **argv)
case 'a': /* Dump data only */
data_only = true;
break;
+ case 'A': /* vAriable */
+ opts->selTypes = 1;
+ opts->selVariable = 1;
+ simple_string_list_append(&opts->variableNames, optarg);
+ break;
case 'c': /* clean (i.e., drop) schema prior to create */
opts->dropSchema = 1;
break;
@@ -479,6 +485,7 @@ usage(const char *progname)
printf(_("\nOptions controlling the restore:\n"));
printf(_(" -a, --data-only restore only the data, no schema\n"));
+ printf(_(" -A, --variable=NAME restore named session variable\n"));
printf(_(" -c, --clean clean (drop) database objects before recreating\n"));
printf(_(" -C, --create create the target database\n"));
printf(_(" -e, --exit-on-error exit on error, default is to continue\n"));
--
2.48.1
[text/x-patch] v20250301-0019-this-patch-changes-error-message-column-doesn-t-exis.patch (29.2K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/22-v20250301-0019-this-patch-changes-error-message-column-doesn-t-exis.patch)
download | inline diff:
From 7ec45fe66443c47f6295e3503e4343b0d8e321fa Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:10:39 +0100
Subject: [PATCH 19/21] this patch changes error message "column doesn't exist"
to message "column or variable doesn't exist"
The error message will be more correct. Today, missing PL/pgSQL variable can be reported. The change has
impact on lot of regress tests not directly related to session variables, and then it is distributed as separate patch
---
src/backend/parser/parse_expr.c | 2 +-
src/backend/parser/parse_relation.c | 24 +++++++++++---
src/backend/parser/parse_target.c | 8 +++--
src/include/parser/parse_expr.h | 2 ++
src/pl/plpgsql/src/expected/plpgsql_array.out | 2 +-
.../plpgsql/src/expected/plpgsql_record.out | 4 +--
.../src/expected/plpgsql_session_variable.out | 2 +-
src/pl/tcl/expected/pltcl_queries.out | 12 +++----
.../isolation/expected/session-variable.out | 4 +--
src/test/regress/expected/alter_table.out | 32 +++++++++----------
src/test/regress/expected/copy2.out | 2 +-
src/test/regress/expected/errors.out | 8 ++---
src/test/regress/expected/join.out | 12 +++----
src/test/regress/expected/namespace.out | 2 +-
src/test/regress/expected/numerology.out | 2 +-
src/test/regress/expected/plpgsql.out | 12 +++----
src/test/regress/expected/psql.out | 2 +-
src/test/regress/expected/rules.out | 2 +-
.../regress/expected/session_variables.out | 6 ++--
src/test/regress/expected/transactions.out | 4 +--
src/test/regress/expected/union.out | 2 +-
21 files changed, 83 insertions(+), 63 deletions(-)
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 158a67be523..7c4a584f0f4 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -526,7 +526,7 @@ transformIndirection(ParseState *pstate, A_Indirection *ind)
* printed. When we are in an expression where session variables cannot be
* used, we raise the first form of error message.
*/
-static bool
+bool
expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
{
bool result = false;
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index bec6947ea2d..7bc75319e50 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -27,6 +27,7 @@
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "parser/parse_enr.h"
+#include "parser/parse_expr.h"
#include "parser/parse_relation.h"
#include "parser/parse_type.h"
#include "parser/parsetree.h"
@@ -3761,6 +3762,19 @@ errorMissingRTE(ParseState *pstate, RangeVar *relation)
parser_errposition(pstate, relation->location)));
}
+/*
+ * set message "column does not exist" or "column or variable does not exist"
+ * in dependency if expression context allows session variables.
+ */
+static int
+column_or_variable_does_not_exists(ParseState *pstate, const char *colname)
+{
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind))
+ return errmsg("column or variable \"%s\" does not exist", colname);
+ else
+ return errmsg("column \"%s\" does not exist", colname);
+}
+
/*
* Generate a suitable error about a missing column.
*
@@ -3795,7 +3809,7 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errdetail("There are columns named \"%s\", but they are in tables that cannot be referenced from this part of the query.",
colname),
!relname ? errhint("Try using a table-qualified name.") : 0,
@@ -3805,7 +3819,7 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errdetail("There is a column named \"%s\" in table \"%s\", but it cannot be referenced from this part of the query.",
colname, state->rexact1->eref->aliasname),
rte_visible_if_lateral(pstate, state->rexact1) ?
@@ -3823,14 +3837,14 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
parser_errposition(pstate, location)));
/* Handle case where we have a single alternative spelling to offer */
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errhint("Perhaps you meant to reference the column \"%s.%s\".",
state->rfirst->eref->aliasname,
strVal(list_nth(state->rfirst->eref->colnames,
@@ -3844,7 +3858,7 @@ errorMissingColumn(ParseState *pstate,
(errcode(ERRCODE_UNDEFINED_COLUMN),
relname ?
errmsg("column %s.%s does not exist", relname, colname) :
- errmsg("column \"%s\" does not exist", colname),
+ column_or_variable_does_not_exists(pstate, colname),
errhint("Perhaps you meant to reference the column \"%s.%s\" or the column \"%s.%s\".",
state->rfirst->eref->aliasname,
strVal(list_nth(state->rfirst->eref->colnames,
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index cf01bff65a9..2a527887a8d 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -779,7 +779,9 @@ transformAssignmentIndirection(ParseState *pstate,
if (!typrelid)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
- errmsg("cannot assign to field \"%s\" of column \"%s\" because its type %s is not a composite type",
+ errmsg(expr_kind_allows_session_variables(pstate->p_expr_kind) ?
+ "cannot assign to field \"%s\" of column or variable \"%s\" because its type %s is not a composite type" :
+ "cannot assign to field \"%s\" of column \"%s\" because its type %s is not a composite type",
strVal(n), targetName,
format_type_be(targetTypeId)),
parser_errposition(pstate, location)));
@@ -788,7 +790,9 @@ transformAssignmentIndirection(ParseState *pstate,
if (attnum == InvalidAttrNumber)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
- errmsg("cannot assign to field \"%s\" of column \"%s\" because there is no such column in data type %s",
+ errmsg(expr_kind_allows_session_variables(pstate->p_expr_kind) ?
+ "cannot assign to field \"%s\" of column or variable \"%s\" because there is no such column in data type %s" :
+ "cannot assign to field \"%s\" of column \"%s\" because there is no such column in data type %s",
strVal(n), targetName,
format_type_be(targetTypeId)),
parser_errposition(pstate, location)));
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index 5bde43758d1..71ec213f884 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -24,4 +24,6 @@ extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKin
extern const char *ParseExprKindName(ParseExprKind exprKind);
+extern bool expr_kind_allows_session_variables(ParseExprKind p_expr_kind);
+
#endif /* PARSE_EXPR_H */
diff --git a/src/pl/plpgsql/src/expected/plpgsql_array.out b/src/pl/plpgsql/src/expected/plpgsql_array.out
index 4c6b3ce998a..ad6692c3e52 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_array.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_array.out
@@ -41,7 +41,7 @@ NOTICE: a = {"(,11)"}, a[1].i = 11
-- perhaps this ought to work, but for now it doesn't:
do $$ declare a complex[];
begin a[1:2].i := array[11,12]; raise notice 'a = %', a; end$$;
-ERROR: cannot assign to field "i" of column "a" because its type complex[] is not a composite type
+ERROR: cannot assign to field "i" of column or variable "a" because its type complex[] is not a composite type
LINE 1: a[1:2].i := array[11,12]
^
QUERY: a[1:2].i := array[11,12]
diff --git a/src/pl/plpgsql/src/expected/plpgsql_record.out b/src/pl/plpgsql/src/expected/plpgsql_record.out
index 6974c8f4a44..3970ac721c9 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_record.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_record.out
@@ -135,7 +135,7 @@ ERROR: record "c" has no field "x"
CONTEXT: PL/pgSQL assignment "c.x.q1 = 1"
PL/pgSQL function inline_code_block line 1 at assignment
do $$ declare c nested_int8s; begin c.c2.x = 1; end $$;
-ERROR: cannot assign to field "x" of column "c" because there is no such column in data type two_int8s
+ERROR: cannot assign to field "x" of column or variable "c" because there is no such column in data type two_int8s
LINE 1: c.c2.x = 1
^
QUERY: c.c2.x = 1
@@ -157,7 +157,7 @@ ERROR: record "c" has no field "x"
CONTEXT: PL/pgSQL assignment "b.c.x.q1 = 1"
PL/pgSQL function inline_code_block line 1 at assignment
do $$ <<b>> declare c nested_int8s; begin b.c.c2.x = 1; end $$;
-ERROR: cannot assign to field "x" of column "b" because there is no such column in data type two_int8s
+ERROR: cannot assign to field "x" of column or variable "b" because there is no such column in data type two_int8s
LINE 1: b.c.c2.x = 1
^
QUERY: b.c.c2.x = 1
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index ecac64fcfb4..8bd2b398bdd 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -232,7 +232,7 @@ SET ROLE TO DEFAULT;
SET ROLE TO regress_var_exec_role;
-- should fail, but not crash
SELECT var_read_func();
-ERROR: column "plpgsql_sv_var1" does not exist
+ERROR: column or variable "plpgsql_sv_var1" does not exist
LINE 1: plpgsql_sv_var1
^
QUERY: plpgsql_sv_var1
diff --git a/src/pl/tcl/expected/pltcl_queries.out b/src/pl/tcl/expected/pltcl_queries.out
index 35cc6e62aad..497cd38189b 100644
--- a/src/pl/tcl/expected/pltcl_queries.out
+++ b/src/pl/tcl/expected/pltcl_queries.out
@@ -450,12 +450,12 @@ CONTEXT: while executing
"__PLTcl_proc_tcl_eval_text spi_prepare\ a\ \"b\ \{\""
in PL/Tcl function tcl_eval(text)
select tcl_error_handling_test($tcl$spi_prepare "select moo" []$tcl$);
- tcl_error_handling_test
---------------------------------------
- SQLSTATE: 42703 +
- condition: undefined_column +
- cursor_position: 8 +
- message: column "moo" does not exist+
+ tcl_error_handling_test
+--------------------------------------------------
+ SQLSTATE: 42703 +
+ condition: undefined_column +
+ cursor_position: 8 +
+ message: column or variable "moo" does not exist+
statement: select moo
(1 row)
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
index e9a254bcd12..d8848d555cd 100644
--- a/src/test/isolation/expected/session-variable.out
+++ b/src/test/isolation/expected/session-variable.out
@@ -10,7 +10,7 @@ test
step drop: DROP VARIABLE myvar;
step val: SELECT myvar;
-ERROR: column "myvar" does not exist
+ERROR: column or variable "myvar" does not exist
starting permutation: let val s1 drop val sr1
step let: LET myvar = 'test';
@@ -23,7 +23,7 @@ test
step s1: BEGIN;
step drop: DROP VARIABLE myvar;
step val: SELECT myvar;
-ERROR: column "myvar" does not exist
+ERROR: column or variable "myvar" does not exist
step sr1: ROLLBACK;
starting permutation: let val dbg drop create dbg val
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index 362f38856d2..299dbdb5e43 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -1298,19 +1298,19 @@ select * from atacc1;
(1 row)
select * from atacc1 order by a;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select * from atacc1 order by a;
^
select * from atacc1 order by "........pg.dropped.1........";
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select * from atacc1 order by "........pg.dropped.1........"...
^
select * from atacc1 group by a;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select * from atacc1 group by a;
^
select * from atacc1 group by "........pg.dropped.1........";
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select * from atacc1 group by "........pg.dropped.1........"...
^
select atacc1.* from atacc1;
@@ -1320,7 +1320,7 @@ select atacc1.* from atacc1;
(1 row)
select a from atacc1;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select a from atacc1;
^
select atacc1.a from atacc1;
@@ -1334,15 +1334,15 @@ select b,c,d from atacc1;
(1 row)
select a,b,c,d from atacc1;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select a,b,c,d from atacc1;
^
select * from atacc1 where a = 1;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: select * from atacc1 where a = 1;
^
select "........pg.dropped.1........" from atacc1;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select "........pg.dropped.1........" from atacc1;
^
select atacc1."........pg.dropped.1........" from atacc1;
@@ -1350,11 +1350,11 @@ ERROR: column atacc1.........pg.dropped.1........ does not exist
LINE 1: select atacc1."........pg.dropped.1........" from atacc1;
^
select "........pg.dropped.1........",b,c,d from atacc1;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select "........pg.dropped.1........",b,c,d from atacc1;
^
select * from atacc1 where "........pg.dropped.1........" = 1;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: select * from atacc1 where "........pg.dropped.1........" = ...
^
-- UPDATEs
@@ -1363,7 +1363,7 @@ ERROR: column "a" of relation "atacc1" does not exist
LINE 1: update atacc1 set a = 3;
^
update atacc1 set b = 2 where a = 3;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: update atacc1 set b = 2 where a = 3;
^
update atacc1 set "........pg.dropped.1........" = 3;
@@ -1371,7 +1371,7 @@ ERROR: column "........pg.dropped.1........" of relation "atacc1" does not exis
LINE 1: update atacc1 set "........pg.dropped.1........" = 3;
^
update atacc1 set b = 2 where "........pg.dropped.1........" = 3;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: update atacc1 set b = 2 where "........pg.dropped.1........"...
^
-- INSERTs
@@ -1419,11 +1419,11 @@ LINE 1: insert into atacc1 ("........pg.dropped.1........",b,c,d) va...
^
-- DELETEs
delete from atacc1 where a = 3;
-ERROR: column "a" does not exist
+ERROR: column or variable "a" does not exist
LINE 1: delete from atacc1 where a = 3;
^
delete from atacc1 where "........pg.dropped.1........" = 3;
-ERROR: column "........pg.dropped.1........" does not exist
+ERROR: column or variable "........pg.dropped.1........" does not exist
LINE 1: delete from atacc1 where "........pg.dropped.1........" = 3;
^
delete from atacc1;
@@ -1716,7 +1716,7 @@ select f1 from c1;
alter table c1 drop column f1;
select f1 from c1;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1 from c1;
^
HINT: Perhaps you meant to reference the column "c1.f2".
@@ -1730,7 +1730,7 @@ ERROR: cannot drop inherited column "f1"
alter table p1 drop column f1;
-- c1.f1 is dropped now, since there is no local definition for it
select f1 from c1;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1 from c1;
^
HINT: Perhaps you meant to reference the column "c1.f2".
diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 64ea33aeae8..6874f5ae0d1 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -160,7 +160,7 @@ LINE 1: COPY x TO stdout WHERE a = 1;
COPY x from stdin WHERE a = 50004;
COPY x from stdin WHERE a > 60003;
COPY x from stdin WHERE f > 60003;
-ERROR: column "f" does not exist
+ERROR: column or variable "f" does not exist
LINE 1: COPY x from stdin WHERE f > 60003;
^
COPY x from stdin WHERE a = max(x.b);
diff --git a/src/test/regress/expected/errors.out b/src/test/regress/expected/errors.out
index 8c527474daf..e53ae451dfc 100644
--- a/src/test/regress/expected/errors.out
+++ b/src/test/regress/expected/errors.out
@@ -27,7 +27,7 @@ LINE 1: select * from nonesuch;
^
-- bad name in target list
select nonesuch from pg_database;
-ERROR: column "nonesuch" does not exist
+ERROR: column or variable "nonesuch" does not exist
LINE 1: select nonesuch from pg_database;
^
-- empty distinct list isn't OK
@@ -37,17 +37,17 @@ LINE 1: select distinct from pg_database;
^
-- bad attribute name on lhs of operator
select * from pg_database where nonesuch = pg_database.datname;
-ERROR: column "nonesuch" does not exist
+ERROR: column or variable "nonesuch" does not exist
LINE 1: select * from pg_database where nonesuch = pg_database.datna...
^
-- bad attribute name on rhs of operator
select * from pg_database where pg_database.datname = nonesuch;
-ERROR: column "nonesuch" does not exist
+ERROR: column or variable "nonesuch" does not exist
LINE 1: ...ect * from pg_database where pg_database.datname = nonesuch;
^
-- bad attribute name in select distinct on
select distinct on (foobar) * from pg_database;
-ERROR: column "foobar" does not exist
+ERROR: column or variable "foobar" does not exist
LINE 1: select distinct on (foobar) * from pg_database;
^
-- grouping with FOR UPDATE
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index a57bb18c24f..96359bdce1a 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -7477,13 +7477,13 @@ LINE 1: select t2.uunique1 from
HINT: Perhaps you meant to reference the column "t2.unique1".
select uunique1 from
tenk1 t1 join tenk2 t2 on t1.two = t2.two; -- error, suggest both at once
-ERROR: column "uunique1" does not exist
+ERROR: column or variable "uunique1" does not exist
LINE 1: select uunique1 from
^
HINT: Perhaps you meant to reference the column "t1.unique1" or the column "t2.unique1".
select ctid from
tenk1 t1 join tenk2 t2 on t1.two = t2.two; -- error, need qualification
-ERROR: column "ctid" does not exist
+ERROR: column or variable "ctid" does not exist
LINE 1: select ctid from
^
DETAIL: There are columns named "ctid", but they are in tables that cannot be referenced from this part of the query.
@@ -8580,7 +8580,7 @@ lateral (select * from int8_tbl t1,
-- test some error cases where LATERAL should have been used but wasn't
select f1,g from int4_tbl a, (select f1 as g) ss;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1,g from int4_tbl a, (select f1 as g) ss;
^
DETAIL: There is a column named "f1" in table "a", but it cannot be referenced from this part of the query.
@@ -8592,7 +8592,7 @@ LINE 1: select f1,g from int4_tbl a, (select a.f1 as g) ss;
DETAIL: There is an entry for table "a", but it cannot be referenced from this part of the query.
HINT: To reference that table, you must mark this subquery with LATERAL.
select f1,g from int4_tbl a cross join (select f1 as g) ss;
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 1: select f1,g from int4_tbl a cross join (select f1 as g) ss;
^
DETAIL: There is a column named "f1" in table "a", but it cannot be referenced from this part of the query.
@@ -8629,7 +8629,7 @@ LINE 1: select 1 from tenk1 a, lateral (select max(a.unique1) from i...
create temp table xx1 as select f1 as x1, -f1 as x2 from int4_tbl;
-- error, can't do this:
update xx1 set x2 = f1 from (select * from int4_tbl where f1 = x1) ss;
-ERROR: column "x1" does not exist
+ERROR: column or variable "x1" does not exist
LINE 1: ... set x2 = f1 from (select * from int4_tbl where f1 = x1) ss;
^
DETAIL: There is a column named "x1" in table "xx1", but it cannot be referenced from this part of the query.
@@ -8649,7 +8649,7 @@ update xx1 set x2 = f1 from xx1, lateral (select * from int4_tbl where f1 = x1)
ERROR: table name "xx1" specified more than once
-- also errors:
delete from xx1 using (select * from int4_tbl where f1 = x1) ss;
-ERROR: column "x1" does not exist
+ERROR: column or variable "x1" does not exist
LINE 1: ...te from xx1 using (select * from int4_tbl where f1 = x1) ss;
^
DETAIL: There is a column named "x1" in table "xx1", but it cannot be referenced from this part of the query.
diff --git a/src/test/regress/expected/namespace.out b/src/test/regress/expected/namespace.out
index dbbda72d395..d98793f92a7 100644
--- a/src/test/regress/expected/namespace.out
+++ b/src/test/regress/expected/namespace.out
@@ -23,7 +23,7 @@ BEGIN;
SET search_path to public, test_ns_schema_1;
CREATE SCHEMA test_ns_schema_2
CREATE VIEW abc_view AS SELECT c FROM abc;
-ERROR: column "c" does not exist
+ERROR: column or variable "c" does not exist
LINE 2: CREATE VIEW abc_view AS SELECT c FROM abc;
^
COMMIT;
diff --git a/src/test/regress/expected/numerology.out b/src/test/regress/expected/numerology.out
index 9e23166fed1..672012e1461 100644
--- a/src/test/regress/expected/numerology.out
+++ b/src/test/regress/expected/numerology.out
@@ -314,7 +314,7 @@ NOTICE: i = 1002
NOTICE: i = 1003
-- error cases
SELECT _100;
-ERROR: column "_100" does not exist
+ERROR: column or variable "_100" does not exist
LINE 1: SELECT _100;
^
SELECT 100_;
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index 0a6945581bd..5c599ba312e 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -2598,7 +2598,7 @@ end; $$ language plpgsql;
-- should fail: SQLSTATE and SQLERRM are only in defined EXCEPTION
-- blocks
select excpt_test1();
-ERROR: column "sqlstate" does not exist
+ERROR: column or variable "sqlstate" does not exist
LINE 1: sqlstate
^
QUERY: sqlstate
@@ -2613,7 +2613,7 @@ begin
end; $$ language plpgsql;
-- should fail
select excpt_test2();
-ERROR: column "sqlstate" does not exist
+ERROR: column or variable "sqlstate" does not exist
LINE 1: sqlstate
^
QUERY: sqlstate
@@ -4675,7 +4675,7 @@ BEGIN
RAISE NOTICE '%, %', r.roomno, r.comment;
END LOOP;
END$$;
-ERROR: column "foo" does not exist
+ERROR: column or variable "foo" does not exist
LINE 1: SELECT rtrim(roomno) AS roomno, foo FROM Room ORDER BY roomn...
^
QUERY: SELECT rtrim(roomno) AS roomno, foo FROM Room ORDER BY roomno
@@ -4717,7 +4717,7 @@ begin
raise notice 'x = %', x;
end;
$$;
-ERROR: column "x" does not exist
+ERROR: column or variable "x" does not exist
LINE 1: x + 1
^
QUERY: x + 1
@@ -4729,7 +4729,7 @@ begin
raise notice 'x = %, y = %', x, y;
end;
$$;
-ERROR: column "x" does not exist
+ERROR: column or variable "x" does not exist
LINE 1: x + 1
^
QUERY: x + 1
@@ -5769,7 +5769,7 @@ ALTER TABLE alter_table_under_transition_tables
DROP column name;
UPDATE alter_table_under_transition_tables
SET id = id;
-ERROR: column "name" does not exist
+ERROR: column or variable "name" does not exist
LINE 1: (SELECT string_agg(id || '=' || name, ',') FROM d)
^
QUERY: (SELECT string_agg(id || '=' || name, ',') FROM d)
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 02a729f1993..97c6a827cb8 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -214,7 +214,7 @@ select $1::int as col \bind 1 \g \bind 2 \g
-- errors
-- parse error
SELECT foo \bind \g
-ERROR: column "foo" does not exist
+ERROR: column or variable "foo" does not exist
LINE 1: SELECT foo
^
-- tcop error
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 62f69ac20b2..3fe58cc06fc 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -1191,7 +1191,7 @@ drop rule rules_foorule on rules_foo;
-- this should fail because f1 is not exposed for unqualified reference:
create rule rules_foorule as on insert to rules_foo where f1 < 100
do instead insert into rules_foo2 values (f1);
-ERROR: column "f1" does not exist
+ERROR: column or variable "f1" does not exist
LINE 2: do instead insert into rules_foo2 values (f1);
^
DETAIL: There are columns named "f1", but they are in tables that cannot be referenced from this part of the query.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index e0aa0408f71..04e23c9097a 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -811,7 +811,7 @@ ERROR: session variable "var1" doesn't exist
LINE 1: LET var1 = pi();
^
SELECT var1;
-ERROR: column "var1" does not exist
+ERROR: column or variable "var1" does not exist
LINE 1: SELECT var1;
^
-- should be ok
@@ -1030,7 +1030,7 @@ SELECT v1;
-- should fail, attribute doesn't exist
LET v1.x = 10;
-ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1
+ERROR: cannot assign to field "x" of column or variable "v1" because there is no such column in data type t1
LINE 1: LET v1.x = 10;
^
-- should fail, don't allow multi column query
@@ -1750,7 +1750,7 @@ BEGIN;
DROP VARIABLE var1;
-- should fail
SELECT var1;
-ERROR: column "var1" does not exist
+ERROR: column or variable "var1" does not exist
LINE 1: SELECT var1;
^
ROLLBACK;
diff --git a/src/test/regress/expected/transactions.out b/src/test/regress/expected/transactions.out
index 7f5757e89c4..b05b16d94bf 100644
--- a/src/test/regress/expected/transactions.out
+++ b/src/test/regress/expected/transactions.out
@@ -256,7 +256,7 @@ SELECT * FROM trans_barbaz; -- should have 1
BEGIN;
SAVEPOINT one;
SELECT trans_foo;
-ERROR: column "trans_foo" does not exist
+ERROR: column or variable "trans_foo" does not exist
LINE 1: SELECT trans_foo;
^
ROLLBACK TO SAVEPOINT one;
@@ -305,7 +305,7 @@ BEGIN;
SAVEPOINT one;
INSERT INTO savepoints VALUES (5);
SELECT trans_foo;
-ERROR: column "trans_foo" does not exist
+ERROR: column or variable "trans_foo" does not exist
LINE 1: SELECT trans_foo;
^
COMMIT;
diff --git a/src/test/regress/expected/union.out b/src/test/regress/expected/union.out
index caa8fe70a05..1d3447e84dd 100644
--- a/src/test/regress/expected/union.out
+++ b/src/test/regress/expected/union.out
@@ -939,7 +939,7 @@ ORDER BY q2,q1;
-- This should fail, because q2 isn't a name of an EXCEPT output column
SELECT q1 FROM int8_tbl EXCEPT SELECT q2 FROM int8_tbl ORDER BY q2 LIMIT 1;
-ERROR: column "q2" does not exist
+ERROR: column or variable "q2" does not exist
LINE 1: ... int8_tbl EXCEPT SELECT q2 FROM int8_tbl ORDER BY q2 LIMIT 1...
^
DETAIL: There is a column named "q2" in table "*SELECT* 2", but it cannot be referenced from this part of the query.
--
2.48.1
[text/x-patch] v20250301-0020-transactional-variables.patch (37.3K, ../../CAFj8pRDw=WVEdAnrLsFGstDaGtY4wNQdz59rpZEpZsVF3p0nfA@mail.gmail.com/23-v20250301-0020-transactional-variables.patch)
download | inline diff:
From dc601b275fd46b0a3f575c094681e009781c7cb4 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 15:11:33 +0100
Subject: [PATCH 20/21] transactional variables
This commit implements transactional variables. The content of transactional
session variables is sensitive to transactions and subtransactions. Any
transactional variable holds a history of values necessary for revert. This history
is cleaned (purged) when a) we read the variable, b) when the transaction is finished.
We don't try to purge, when the last modification of a variable is from
current subtransaction, or when purge was processed in current subtransaction.
This patch is based on my work from Feb 2020 and it is related to discussion
about features related to session variables. Now, when the all features are
separated to isolated patches I can revitalize this patch, because it doesn't
increase complexity of basic patches.
Unlike other patches, this patch is without any review at this moment (Feb 2024),
but the feature should be fully functional for people who are interested about
this feature (for testing).
---
doc/src/sgml/catalogs.sgml | 12 +
doc/src/sgml/ref/create_variable.sgml | 10 +-
src/backend/catalog/pg_variable.c | 4 +
src/backend/commands/session_variable.c | 301 +++++++++++++++++-
src/backend/parser/gram.y | 50 +--
src/bin/pg_dump/pg_dump.c | 10 +-
src/bin/pg_dump/pg_dump.h | 1 +
src/bin/pg_dump/t/002_pg_dump.pl | 36 +++
src/bin/psql/describe.c | 4 +-
src/bin/psql/tab-complete.in.c | 5 +
src/include/catalog/pg_variable.h | 3 +
src/include/nodes/parsenodes.h | 1 +
src/include/parser/kwlist.h | 1 +
src/test/regress/expected/psql.out | 36 +--
.../regress/expected/session_variables.out | 100 ++++++
src/test/regress/sql/session_variables.sql | 58 ++++
16 files changed, 587 insertions(+), 45 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index c7a8170ddf2..1217f8f8647 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9884,6 +9884,18 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry><structfield>varistransact</structfield></entry>
+ <entry><type>boolean</type></entry>
+ <entry></entry>
+ <entry>
+ True, when the variable is <quote>transactional</quote>. In the case
+ of a transaction rollback, transactional variables are reset to the
+ value they had when the transaction started. The default value is
+ <literal>false</literal>.
+ </entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>vareoxaction</structfield> <type>char</type>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index 3c3e6d55b69..1aadd3677e5 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -26,7 +26,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-CREATE [ { TEMPORARY | TEMP } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+CREATE [ { TEMPORARY | TEMP } ] [ { TRANSACTIONAL | TRANSACTION } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
[ NOT NULL ] [ DEFAULT <replaceable class="parameter">default_expr</replaceable> ] [ { ON COMMIT DROP | ON TRANSACTION END RESET } ]
</synopsis>
</refsynopsisdiv>
@@ -47,6 +47,14 @@ CREATE [ { TEMPORARY | TEMP } ] [ IMMUTABLE ] VARIABLE [ IF NOT EXISTS ] <replac
same as regular variables in procedural languages.
</para>
+ <para>
+ When a schema variable is created with a
+ <command>CREATE TRANSACTIONAL VARIABLE</command> command, the variables
+ content changes are transactional: in case of rollback, they are reset to
+ their value at the beginning of the transaction or the latest subtransaction.
+ The variable content is only hold in memory, and thus is not persistent.
+ </para>
+
<para>
Session variables are retrieved by the <command>SELECT</command>
command. Their value is set with the <command>LET</command> command.
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 0b6093a00ba..fa49e7233d5 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -42,6 +42,7 @@ static ObjectAddress create_variable(const char *varName,
bool if_not_exists,
bool not_null,
bool is_immutable,
+ bool is_transact,
Node *varDefexpr,
VariableXactEndAction varXactEndAction);
@@ -59,6 +60,7 @@ create_variable(const char *varName,
bool if_not_exists,
bool not_null,
bool is_immutable,
+ bool is_transact,
Node *varDefexpr,
VariableXactEndAction varXactEndAction)
{
@@ -123,6 +125,7 @@ create_variable(const char *varName,
values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
values[Anum_pg_variable_varnotnull - 1] = BoolGetDatum(not_null);
values[Anum_pg_variable_varisimmutable - 1] = BoolGetDatum(is_immutable);
+ values[Anum_pg_variable_varistransact - 1] = BoolGetDatum(is_transact);
values[Anum_pg_variable_varxactendaction - 1] = CharGetDatum(varXactEndAction);
if (varDefexpr)
@@ -267,6 +270,7 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
stmt->if_not_exists,
stmt->not_null,
stmt->is_immutable,
+ stmt->is_transact,
cooked_default,
stmt->XactEndAction);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index b08c1b47d38..5ac488795a1 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -47,6 +47,19 @@ typedef struct SVariableXActDropItem
SubTransactionId deleting_subid;
} SVariableXActDropItem;
+/*
+ * Used for transactional variables. Holds prev version.
+ */
+typedef struct PrevValue
+{
+ Datum value;
+ bool isnull;
+
+ SubTransactionId modify_subid;
+
+ struct PrevValue *prev_value;
+} PrevValue;
+
/*
* The values of session variables are stored in the backend's private memory
* in the dedicated memory context SVariableMemoryContext in binary format.
@@ -68,6 +81,25 @@ typedef struct SVariableData
bool isnull;
Datum value;
+ /*
+ * We don't need stack versions modified in same subtransaction.
+ * Used by transactional variables only. The value of transactional
+ * variable can be returned immediately when modify_subid is same
+ * like current subid.
+ */
+ SubTransactionId modify_subid;
+
+ /*
+ * When the modify_subid is different than current subid, then
+ * we need to recheck versions and throw versions related to
+ * reverted transactions. When purge_subid is same like current subid
+ * we can return the value of transaction variable without this
+ * recheck.
+ */
+ SubTransactionId purge_subid;
+
+ PrevValue *prev_value;
+
Oid typid;
int16 typlen;
bool typbyval;
@@ -86,6 +118,7 @@ typedef struct SVariableData
bool not_null;
bool is_immutable;
+ bool is_transact;
bool reset_at_eox;
@@ -125,6 +158,9 @@ static bool needs_validation = false;
*/
static bool has_session_variables_with_reset_at_eox = false;
+/* true, when transactional variables was modified */
+static bool has_modified_transactional_variables = false;
+
/*
* The content of dropped session variables is not removed immediately. If
* possible, we do that at the end of the transaction. But we cannot do that
@@ -140,6 +176,7 @@ static List *xact_drop_items = NIL;
static void register_session_variable_xact_drop(Oid varid);
static void unregister_session_variable_xact_drop(Oid varid);
+static bool purge_session_variable(SVariable svar);
/*
* Callback function for session variable invalidation.
@@ -292,8 +329,25 @@ unregister_session_variable_xact_drop(Oid varid)
* Release stored value, free memory
*/
static void
-free_session_variable_value(SVariable svar)
+free_session_variable_value(SVariable svar, bool deep_free)
{
+ if (deep_free)
+ {
+ PrevValue *prev_value = svar->prev_value;
+ PrevValue *next_value;
+
+ while (prev_value)
+ {
+ if (!svar->typbyval)
+ pfree(DatumGetPointer(prev_value->value));
+
+ next_value = prev_value->prev_value;
+ pfree(prev_value);
+
+ prev_value = next_value;
+ }
+ }
+
/* clean the current value */
if (!svar->isnull)
{
@@ -390,7 +444,7 @@ remove_invalid_session_variables(bool atEOX)
{
Oid varid = svar->varid;
- free_session_variable_value(svar);
+ free_session_variable_value(svar, true);
hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
svar = NULL;
}
@@ -426,6 +480,94 @@ remove_session_variables_with_reset_at_eox(void)
has_session_variables_with_reset_at_eox = false;
}
+/*
+ * remove prev values at eox
+ */
+static void
+remove_prev_values_at_eox(bool isCommit)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ if (!sessionvars)
+ return;
+
+ /* leave quckly, when there are not that variables */
+ if (!has_modified_transactional_variables)
+ return;
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (svar->is_transact && svar->modify_subid != InvalidSubTransactionId)
+ {
+ if (isCommit)
+ {
+ if (purge_session_variable(svar))
+ {
+ PrevValue *prev_value = svar->prev_value;
+
+ while (prev_value)
+ {
+ PrevValue *current_pv = prev_value;
+
+ if (!svar->typbyval && !current_pv->isnull)
+ pfree(DatumGetPointer(current_pv->value));
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+ }
+ }
+ else
+ {
+ hash_search(sessionvars, &svar->varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ }
+ else
+ {
+ PrevValue *prev_value = svar->prev_value;
+
+ while (prev_value)
+ {
+ PrevValue *current_pv = prev_value;
+
+ if (current_pv->modify_subid == InvalidSubTransactionId)
+ break;
+
+ if (!svar->typbyval && !current_pv->isnull)
+ pfree(DatumGetPointer(current_pv->value));
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+ }
+
+ if (prev_value)
+ {
+ svar->value = prev_value->value;
+ svar->isnull = prev_value->isnull;
+
+ pfree(prev_value);
+ }
+ else
+ {
+ hash_search(sessionvars, &svar->varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ }
+
+ /* when svar is still valid (not removed from sessionvars */
+ if (svar)
+ {
+ svar->modify_subid = InvalidSubTransactionId;
+ svar->prev_value = NULL;
+ }
+ }
+ }
+
+ has_modified_transactional_variables = false;
+}
+
/*
* Perform ON COMMIT DROP for temporary session variables,
* and remove all dropped variables from memory.
@@ -473,6 +615,8 @@ AtPreEOXact_SessionVariables(bool isCommit)
remove_invalid_session_variables(true);
}
+ remove_prev_values_at_eox(isCommit);
+
/*
* We have to clean xact_drop_items. All related variables are dropped
* now, or lost inside aborted transaction.
@@ -618,6 +762,7 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
svar->not_null = varform->varnotnull;
svar->is_immutable = varform->varisimmutable;
+ svar->is_transact = varform->varistransact;
svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
svar->domain_check_extra = NULL;
@@ -643,6 +788,17 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
svar->isnull = true;
svar->value = (Datum) 0;
+ if (svar->is_transact)
+ {
+ svar->modify_subid = GetCurrentSubTransactionId();
+ has_modified_transactional_variables = true;
+ }
+ else
+ svar->modify_subid = InvalidSubTransactionId;
+
+ svar->purge_subid = InvalidSubTransactionId;
+ svar->prev_value = NULL;
+
svar->is_valid = true;
svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
@@ -676,6 +832,69 @@ setup_session_variable(SVariable svar, Oid varid, bool is_write)
ReleaseSysCache(tup);
}
+/*
+ * Try to remove all previous versions related to reverted transactions.
+ * Returns true, when valid version was found.
+ */
+static bool
+purge_session_variable(SVariable svar)
+{
+ SubTransactionId current_subid;
+ PrevValue *prev_value;
+ bool found = true;
+
+ Assert(svar->is_transact);
+
+ if (svar->modify_subid == InvalidSubTransactionId)
+ return true;
+
+ current_subid = GetCurrentSubTransactionId();
+
+ if (svar->modify_subid == current_subid)
+ return true;
+
+ if (svar->purge_subid == current_subid)
+ return true;
+
+ if (SubTransactionIsActive(svar->modify_subid))
+ {
+ svar->purge_subid = current_subid;
+ return true;
+ }
+
+ prev_value = svar->prev_value;
+
+ while (prev_value)
+ {
+ PrevValue *current_pv = prev_value;
+
+ if (current_pv->modify_subid == InvalidSubTransactionId ||
+ SubTransactionIsActive(current_pv->modify_subid))
+ {
+ svar->value = current_pv->value;
+ svar->isnull = current_pv->isnull;
+ svar->modify_subid = current_pv->modify_subid;
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+
+ found = true;
+ break;
+ }
+
+ if (!svar->typbyval && !current_pv->isnull)
+ pfree(DatumGetPointer(current_pv->value));
+
+ prev_value = current_pv->prev_value;
+ pfree(current_pv);
+ }
+
+ svar->prev_value = prev_value;
+ svar->purge_subid = current_subid;
+
+ return found;
+}
+
/*
* Assign a new value to the session variable. It is copied to
* SVariableMemoryContext if necessary.
@@ -688,6 +907,10 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
Datum newval;
SVariableData locsvar,
*_svar;
+ SubTransactionId current_subid = GetCurrentSubTransactionId();
+ SubTransactionId prev_purge_subid = InvalidSubTransactionId;
+ bool save_prev_value;
+ PrevValue *prev_value;
Assert(svar);
Assert(!isnull || value == (Datum) 0);
@@ -723,6 +946,21 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
else
_svar = svar;
+ if (_svar->is_transact && _svar->create_lsn == svar->create_lsn)
+ {
+ Assert(svar->typid == _svar->typid);
+ Assert(svar->typbyval == _svar->typbyval);
+ Assert(svar->typlen == _svar->typlen);
+
+ save_prev_value = svar->modify_subid != current_subid;
+ prev_value = svar->prev_value;
+ }
+ else
+ {
+ save_prev_value = false;
+ prev_value = NULL;
+ }
+
if (!isnull)
{
MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
@@ -734,7 +972,37 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
else
newval = value;
- free_session_variable_value(svar);
+ if (save_prev_value)
+ {
+ volatile PrevValue *new_prev_value;
+
+ PG_TRY();
+ {
+ new_prev_value = MemoryContextAlloc(SVariableMemoryContext,
+ sizeof(PrevValue));
+ }
+ PG_CATCH();
+ {
+ /* release mem from persistent content */
+ if (newval != value)
+ pfree(DatumGetPointer(newval));
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
+
+ new_prev_value->value = svar->value;
+ new_prev_value->isnull = svar->isnull;
+ new_prev_value->modify_subid = svar->modify_subid;
+ new_prev_value->prev_value = prev_value;
+
+ prev_value = (PrevValue *) new_prev_value;
+ prev_purge_subid = svar->purge_subid;
+
+ has_modified_transactional_variables = true;
+
+ }
+ else
+ free_session_variable_value(svar, prev_value == NULL);
elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value",
get_namespace_name(get_session_variable_namespace(svar->varid)),
@@ -747,6 +1015,9 @@ set_session_variable(SVariable svar, Datum value, bool isnull)
svar->value = newval;
svar->isnull = isnull;
+ svar->modify_subid = current_subid;
+ svar->purge_subid = prev_purge_subid;
+ svar->prev_value = prev_value;
/* don't allow more changes of value when variable is IMMUTABLE */
if (svar->is_immutable)
@@ -848,6 +1119,8 @@ get_session_variable(Oid varid)
else
svar->is_valid = false;
+reinit:
+
/*
* Force setup for not yet initialized variables or variables that cannot
* be validated.
@@ -880,6 +1153,28 @@ get_session_variable(Oid varid)
varid);
}
+ /*
+ * Transactional variables should be purged before (remove
+ * versions created by possibly reverted subtransactions).
+ */
+ if (svar->is_transact &&
+ svar->modify_subid != GetCurrentSubTransactionId() &&
+ svar->modify_subid != InvalidSubTransactionId)
+ {
+ if (!purge_session_variable(svar))
+ {
+ /* force reinit */
+ svar->is_valid = false;
+
+ /*
+ * In next iteration modify_subid should be
+ * InvalidSubTransactionId or current subid,
+ * so there is not risk of infinity cycle.
+ */
+ goto reinit;
+ }
+ }
+
/* ensure the returned data is still of the correct domain */
if (svar->is_domain)
{
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 1c96bbf0819..bc5302f0fcf 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -675,7 +675,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
json_object_constructor_null_clause_opt
json_array_constructor_null_clause_opt
-%type <boolean> OptNotNull OptImmutable
+%type <boolean> OptNotNull OptImmutable OptTransactional
/*
* Non-keyword token types. These are hard-wired into the "flex" lexer.
@@ -780,7 +780,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
SUBSCRIPTION SUBSTRING SUPPORT SYMMETRIC SYSID SYSTEM_P SYSTEM_USER
TABLE TABLES TABLESAMPLE TABLESPACE TARGET TEMP TEMPLATE TEMPORARY TEXT_P THEN
- TIES TIME TIMESTAMP TO TRAILING TRANSACTION TRANSFORM
+ TIES TIME TIMESTAMP TO TRAILING TRANSACTION TRANSACTIONAL TRANSFORM
TREAT TRIGGER TRIM TRUE_P
TRUNCATE TRUSTED TYPE_P TYPES_P
@@ -5274,31 +5274,33 @@ create_extension_opt_item:
*****************************************************************************/
CreateSessionVarStmt:
- CREATE OptTemp OptImmutable VARIABLE qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
+ CREATE OptTemp OptTransactional OptImmutable VARIABLE qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $5->relpersistence = $2;
- n->is_immutable = $3;
- n->variable = $5;
- n->typeName = $7;
- n->collClause = (CollateClause *) $8;
- n->not_null = $9;
- n->defexpr = $10;
- n->XactEndAction = $11;
+ $6->relpersistence = $2;
+ n->is_immutable = $4;
+ n->is_transact = $3;
+ n->variable = $6;
+ n->typeName = $8;
+ n->collClause = (CollateClause *) $9;
+ n->not_null = $10;
+ n->defexpr = $11;
+ n->XactEndAction = $12;
n->if_not_exists = false;
$$ = (Node *) n;
}
- | CREATE OptTemp OptImmutable VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
+ | CREATE OptTemp OptTransactional OptImmutable VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause OptNotNull OptSessionVarDefExpr XactEndActionOption
{
CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
- $8->relpersistence = $2;
- n->is_immutable = $3;
- n->variable = $8;
- n->typeName = $10;
- n->collClause = (CollateClause *) $11;
- n->not_null = $12;
- n->defexpr = $13;
- n->XactEndAction = $14;
+ $9->relpersistence = $2;
+ n->is_immutable = $4;
+ n->is_transact = $3;
+ n->variable = $9;
+ n->typeName = $11;
+ n->collClause = (CollateClause *) $12;
+ n->not_null = $13;
+ n->defexpr = $14;
+ n->XactEndAction = $15;
n->if_not_exists = true;
$$ = (Node *) n;
}
@@ -5326,6 +5328,12 @@ OptImmutable: IMMUTABLE { $$ = true; }
| /* EMPTY */ { $$ = false; }
;
+OptTransactional:
+ TRANSACTION { $$ = true; }
+ | TRANSACTIONAL { $$ = true; }
+ | /* EMPTY */ { $$ = false; }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
@@ -18174,6 +18182,7 @@ unreserved_keyword:
| TEXT_P
| TIES
| TRANSACTION
+ | TRANSACTIONAL
| TRANSFORM
| TRIGGER
| TRUNCATE
@@ -18824,6 +18833,7 @@ bare_label_keyword:
| TIMESTAMP
| TRAILING
| TRANSACTION
+ | TRANSACTIONAL
| TRANSFORM
| TREAT
| TRIGGER
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index ca8e496ce26..679f6cf58bb 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -5477,6 +5477,7 @@ getVariables(Archive *fout)
int i_varcollation;
int i_varnotnull;
int i_varisimmutable;
+ int i_varistransact;
int i_varacl;
int i_acldefault;
int i,
@@ -5499,6 +5500,7 @@ getVariables(Archive *fout)
" END AS varcollation,\n"
" v.varnotnull,\n"
" v.varisimmutable,\n"
+ " v.varistransact,\n"
" pg_catalog.pg_get_expr(v.vardefexpr,0) as vardefexpr,\n"
" v.varowner, v.varacl,\n"
" acldefault('V', v.varowner) AS acldefault\n"
@@ -5521,6 +5523,7 @@ getVariables(Archive *fout)
i_varcollation = PQfnumber(res, "varcollation");
i_varnotnull = PQfnumber(res, "varnotnull");
i_varisimmutable = PQfnumber(res, "varisimmutable");
+ i_varistransact = PQfnumber(res, "varistransact");
i_varowner = PQfnumber(res, "varowner");
i_varacl = PQfnumber(res, "varacl");
@@ -5549,6 +5552,7 @@ getVariables(Archive *fout)
varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
varinfo[i].varnotnull = *(PQgetvalue(res, i, i_varnotnull)) == 't';
varinfo[i].varisimmutable = *(PQgetvalue(res, i, i_varisimmutable)) == 't';
+ varinfo[i].varistransact = *(PQgetvalue(res, i, i_varistransact)) == 't';
varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
@@ -5596,6 +5600,7 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
const char *vardefexpr;
const char *varxactendaction;
const char *varisimmutable;
+ const char *varistransact;
Oid varcollation;
bool varnotnull;
@@ -5613,12 +5618,13 @@ dumpVariable(Archive *fout, const VariableInfo *varinfo)
varcollation = varinfo->varcollation;
varnotnull = varinfo->varnotnull;
varisimmutable = varinfo->varisimmutable ? "IMMUTABLE " : "";
+ varistransact = varinfo->varistransact ? "TRANSACTIONAL " : "";
appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
qualvarname);
- appendPQExpBuffer(query, "CREATE %sVARIABLE %s AS %s",
- varisimmutable, qualvarname, vartypname);
+ appendPQExpBuffer(query, "CREATE %s%sVARIABLE %s AS %s",
+ varistransact, varisimmutable, qualvarname, vartypname);
if (OidIsValid(varcollation))
{
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index f1ee2d3eff6..fa5d47ba718 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -746,6 +746,7 @@ typedef struct _VariableInfo
const char *rolname; /* name of owner, or empty string */
bool varnotnull;
bool varisimmutable;
+ bool varistransact;
} VariableInfo;
/*
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index b955bc7cec2..7deba54a41d 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -4201,6 +4201,42 @@ my %tests = (
},
},
+ 'CREATE TRANSACTIONAL VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE TRANSACTIONAL VARIABLE dump_test.variable8 AS integer',
+ regexp => qr/^
+ \QCREATE TRANSACTIONAL VARIABLE dump_test.variable8 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
+ 'CREATE TRANSACTIONAL IMMUTABLE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE TRANSACTIONAL IMMUTABLE VARIABLE dump_test.variable9 AS integer',
+ regexp => qr/^
+ \QCREATE TRANSACTIONAL IMMUTABLE VARIABLE dump_test.variable9 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 503ae160398..f7c1e414485 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -5331,7 +5331,7 @@ listVariables(const char *pattern, bool verbose)
PQExpBufferData buf;
PGresult *res;
printQueryOpt myopt = pset.popt;
- static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false, false, false};
+ static const bool translate_columns[] = {false, false, false, false, false, false, false, false, false, false, false, false};
if (pset.sversion < 180000)
{
@@ -5354,6 +5354,7 @@ listVariables(const char *pattern, bool verbose)
" pg_catalog.pg_get_userbyid(v.varowner) as \"%s\",\n"
" NOT v.varnotnull as \"%s\",\n"
" NOT v.varisimmutable as \"%s\",\n"
+ " v.varistransact as \"%s\",\n"
" pg_catalog.pg_get_expr(v.vardefexpr, 0) as \"%s\",\n"
" CASE v.varxactendaction\n"
" WHEN 'd' THEN 'ON COMMIT DROP'\n"
@@ -5366,6 +5367,7 @@ listVariables(const char *pattern, bool verbose)
gettext_noop("Owner"),
gettext_noop("Nullable"),
gettext_noop("Mutable"),
+ gettext_noop("Transactional"),
gettext_noop("Default"),
gettext_noop("Transactional end action"));
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 7594ce2fa18..9a7cea6c342 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1319,6 +1319,8 @@ static const pgsql_thing_t words_after_create[] = {
* TABLE ... */
{"TEXT SEARCH", NULL, NULL, NULL},
{"TRANSFORM", NULL, NULL, NULL, NULL, THING_NO_ALTER},
+ {"TRANSACTIONAL", NULL, NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE TRANSACTIONAL
+ * VARIABLE ... */
{"TRIGGER", "SELECT tgname FROM pg_catalog.pg_trigger WHERE tgname LIKE '%s' AND NOT tgisinternal"},
{"TYPE", NULL, NULL, &Query_for_list_of_datatypes},
{"UNIQUE", NULL, NULL, NULL, NULL, THING_NO_DROP | THING_NO_ALTER}, /* for CREATE UNIQUE
@@ -3991,8 +3993,11 @@ match_previous_words(int pattern_id,
}
/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE VARIABLE <name> with AS */
+ else if (Matches("CREATE", "TRANSACTION|TRANSACTIONAL"))
+ COMPLETE_WITH("IMMUTABLE", "VARIABLE");
else if (TailMatches("CREATE", "VARIABLE", MatchAny) ||
TailMatches("TEMP|TEMPORARY", "VARIABLE", MatchAny) ||
+ TailMatches("TRANSACTION|TRANSACTIONAL", "VARIABLE", MatchAny) ||
TailMatches("IMMUTABLE", "VARIABLE", MatchAny))
COMPLETE_WITH("AS");
else if (TailMatches("VARIABLE", MatchAny, "AS"))
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index cf21e0426a7..454bb297097 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -62,6 +62,9 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* don't allow changes */
bool varisimmutable BKI_DEFAULT(f);
+ /* supports transactions */
+ bool varistransact BKI_DEFAULT(f);
+
/* action on transaction end */
char varxactendaction BKI_DEFAULT(n);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 8d0d7cf6ec9..e02b7c0a31c 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3550,6 +3550,7 @@ typedef struct CreateSessionVarStmt
bool if_not_exists; /* do nothing if it already exists */
bool not_null; /* disallow nulls */
bool is_immutable; /* don't allow changes */
+ bool is_transact; /* supports transactions */
Node *defexpr; /* default expression */
char XactEndAction; /* on transaction end action */
} CreateSessionVarStmt;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 431167f6b43..e19b957739f 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -456,6 +456,7 @@ PG_KEYWORD("timestamp", TIMESTAMP, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("to", TO, RESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("trailing", TRAILING, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("transaction", TRANSACTION, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("transactional", TRANSACTIONAL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("transform", TRANSFORM, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("treat", TREAT, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("trigger", TRIGGER, UNRESERVED_KEYWORD, BARE_LABEL)
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 97c6a827cb8..140b189bfa9 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6026,20 +6026,20 @@ CREATE ROLE regress_variable_owner;
SET ROLE TO regress_variable_owner;
CREATE VARIABLE var1 AS varchar COLLATE "C";
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+-------------------+-------------
- public | var1 | character varying | C | regress_variable_owner | t | t | | | |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------------+---------+--------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | f | | | |
(1 row)
GRANT SELECT ON VARIABLE var1 TO PUBLIC;
COMMENT ON VARIABLE var1 IS 'some description';
\dV+ var1
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action | Access privileges | Description
---------+------+-------------------+-----------+------------------------+----------+---------+---------+--------------------------+--------------------------------------------------+------------------
- public | var1 | character varying | C | regress_variable_owner | t | t | | | regress_variable_owner=rw/regress_variable_owner+| some description
- | | | | | | | | | =r/regress_variable_owner |
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+----------+---------+---------------+---------+--------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | t | t | f | | | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | | | | | | =r/regress_variable_owner |
(1 row)
DROP VARIABLE var1;
@@ -6507,9 +6507,9 @@ List of schemas
(0 rows)
\dV "no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
---------+------+------+-----------+-------+----------+---------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------------+---------+--------------------------
(0 rows)
-- again, but with dotted schema qualifications.
@@ -6682,9 +6682,9 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
\dV "no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
---------+------+------+-----------+-------+----------+---------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------------+---------+--------------------------
(0 rows)
-- again, but with current database and dotted schema qualifications.
@@ -6821,9 +6821,9 @@ List of text search templates
(0 rows)
\dV regression."no.such.schema"."no.such.variable"
- List of variables
- Schema | Name | Type | Collation | Owner | Nullable | Mutable | Default | Transactional end action
---------+------+------+-----------+-------+----------+---------+---------+--------------------------
+ List of variables
+ Schema | Name | Type | Collation | Owner | Nullable | Mutable | Transactional | Default | Transactional end action
+--------+------+------+-----------+-------+----------+---------+---------------+---------+--------------------------
(0 rows)
-- again, but with dotted database and dotted schema qualifications.
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 04e23c9097a..a816ef6d49f 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -2502,3 +2502,103 @@ SELECT var1;
LET var1 = 30;
ERROR: session variable "public.var1" is declared IMMUTABLE
DROP VARIABLE var1;
+-- test transactional variables
+CREATE TRANSACTION VARIABLE tv AS int DEFAULT 0;
+BEGIN;
+ LET tv = 100;
+ SELECT tv;
+ tv
+-----
+ 100
+(1 row)
+
+ROLLBACK;
+SELECT tv;
+ tv
+----
+ 0
+(1 row)
+
+LET tv = 100;
+BEGIN;
+ LET tv = 1000;
+COMMIT;
+SELECT tv;
+ tv
+------
+ 1000
+(1 row)
+
+BEGIN;
+ LET tv = 0;
+ SELECT tv;
+ tv
+----
+ 0
+(1 row)
+
+ROLLBACK;
+SELECT tv;
+ tv
+------
+ 1000
+(1 row)
+
+-- test subtransactions
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ tv
+----
+ 2
+(1 row)
+
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+ tv
+----
+ 1
+(1 row)
+
+ROLLBACK;
+SELECT tv;
+ tv
+------
+ 1000
+(1 row)
+
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ tv
+----
+ 2
+(1 row)
+
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+ tv
+----
+ 1
+(1 row)
+
+COMMIT;
+SELECT tv;
+ tv
+----
+ 1
+(1 row)
+
+DROP VARIABLE tv;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index c8c2295adbd..880f60e9917 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1735,3 +1735,61 @@ SELECT var1;
LET var1 = 30;
DROP VARIABLE var1;
+
+-- test transactional variables
+CREATE TRANSACTION VARIABLE tv AS int DEFAULT 0;
+
+BEGIN;
+ LET tv = 100;
+ SELECT tv;
+ROLLBACK;
+
+SELECT tv;
+
+LET tv = 100;
+BEGIN;
+ LET tv = 1000;
+COMMIT;
+
+SELECT tv;
+
+BEGIN;
+ LET tv = 0;
+ SELECT tv;
+ROLLBACK;
+
+SELECT tv;
+
+-- test subtransactions
+
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+ROLLBACK;
+
+SELECT tv;
+
+BEGIN;
+ LET tv = 1;
+SAVEPOINT x1;
+ LET tv = 2;
+SAVEPOINT x2;
+ LET tv = 3;
+ROLLBACK TO x2;
+ SELECT tv;
+ LET tv = 10;
+ROLLBACK TO x1;
+ SELECT tv;
+COMMIT;
+
+SELECT tv;
+
+DROP VARIABLE tv;
--
2.48.1
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-03-17 18:32 ` Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Pavel Stehule @ 2025-03-17 18:32 UTC (permalink / raw)
To: jian he <[email protected]>; +Cc: Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
Hi
I was asked for sending a reduced patchset
Regards
Pavel
Attachments:
[text/x-patch] v20250317-0003-function-pg_session_variables-for-cleaning-tests.patch (4.3K, ../../CAFj8pRC_2tHski1K4hUMZm0+T4y7na4d8hwgMMF7Y0MXhfUhbg@mail.gmail.com/3-v20250317-0003-function-pg_session_variables-for-cleaning-tests.patch)
download | inline diff:
From eb368fb47e65989ad3df3ee7aeeb0cbe1a3f81c1 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 20:01:56 +0100
Subject: [PATCH 03/21] function pg_session_variables for cleaning tests
This is a function designed for testing and debugging. It returns the
content of sessionvars as-is, and can therefore display entries about
session variables that were dropped but for which this backend didn't
process the shared invalidations yet.
---
src/backend/commands/session_variable.c | 92 +++++++++++++++++++++++++
src/include/catalog/pg_proc.dat | 8 +++
2 files changed, 100 insertions(+)
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index d2891a1dcb7..fa16f47072e 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -527,3 +527,95 @@ ExecuteLetStmt(ParseState *pstate,
PopActiveSnapshot();
}
+
+/*
+ * pg_session_variables - designed for testing
+ *
+ * This is a function designed for testing and debugging. It returns the
+ * content of session variables as-is, and can therefore display data about
+ * session variables that were dropped, but for which this backend didn't
+ * process the shared invalidations yet.
+ */
+Datum
+pg_session_variables(PG_FUNCTION_ARGS)
+{
+#define NUM_PG_SESSION_VARIABLES_ATTS 8
+
+ InitMaterializedSRF(fcinfo, 0);
+
+ if (sessionvars)
+ {
+ ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ Datum values[NUM_PG_SESSION_VARIABLES_ATTS];
+ bool nulls[NUM_PG_SESSION_VARIABLES_ATTS];
+ HeapTuple tp;
+ bool var_is_valid = false;
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, 0, sizeof(nulls));
+
+ values[0] = ObjectIdGetDatum(svar->varid);
+ values[3] = ObjectIdGetDatum(svar->typid);
+
+ /*
+ * It is possible that the variable has been dropped from the
+ * catalog, but not yet purged from the hash table.
+ */
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ Form_pg_variable varform = (Form_pg_variable) GETSTRUCT(tp);
+
+ /*
+ * It is also possible that a variable has been dropped and
+ * someone created a new variable with the same object ID. Use
+ * the catalog information only if that is not the case.
+ */
+ if (svar->create_lsn == varform->varcreate_lsn)
+ {
+ values[1] = CStringGetTextDatum(
+ get_namespace_name(varform->varnamespace));
+
+ values[2] = CStringGetTextDatum(NameStr(varform->varname));
+ values[4] = CStringGetTextDatum(format_type_be(svar->typid));
+ values[5] = BoolGetDatum(false);
+
+ values[6] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_SELECT) == ACLCHECK_OK);
+
+ values[7] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_UPDATE) == ACLCHECK_OK);
+
+ var_is_valid = true;
+ }
+
+ ReleaseSysCache(tp);
+ }
+
+ /* if there is no matching catalog entry, return null values */
+ if (!var_is_valid)
+ {
+ nulls[1] = true;
+ nulls[2] = true;
+ nulls[4] = true;
+ values[5] = BoolGetDatum(true);
+ nulls[6] = true;
+ nulls[7] = true;
+ }
+
+ tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
+ }
+ }
+
+ return (Datum) 0;
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 2d89008e60f..cec5e915e5f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -12502,4 +12502,12 @@
proargtypes => 'int4',
prosrc => 'gist_stratnum_common' },
+# Session variables support
+{ oid => '8488', descr => 'list of used session variables',
+ proname => 'pg_session_variables', prorows => '1000', proretset => 't',
+ provolatile => 's', proparallel => 'r', prorettype => 'record',
+ proargtypes => '', proallargtypes => '{oid,text,text,oid,text,bool,bool,bool}',
+ proargmodes => '{o,o,o,o,o,o,o,o}',
+ proargnames => '{varid,schema,name,typid,typname,removed,can_select,can_update}',
+ prosrc => 'pg_session_variables' },
]
--
2.48.1
[text/x-patch] v20250317-0002-Storage-for-session-variables-and-SQL-interface.patch (159.6K, ../../CAFj8pRC_2tHski1K4hUMZm0+T4y7na4d8hwgMMF7Y0MXhfUhbg@mail.gmail.com/4-v20250317-0002-Storage-for-session-variables-and-SQL-interface.patch)
download | inline diff:
From d63036f2c437499a95c17b1bd6167bcdc979b2fc Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Thu, 6 Jul 2023 08:29:21 +0200
Subject: [PATCH 02/21] Storage for session variables and SQL interface
Session variables are stored in session memory in a dedicated hash table.
They are set by the LET command and read by the SELECT command.
The access rights should be checked.
The identifiers of session variables should always be shadowed by possible
column identifiers: we don't want to break an application by creating some
badly named session variable.
The limits of this patch (solved by other patches):
- session variables block parallel execution
- session variables blocks simple expression evaluation (in plpgsql)
- SQL functions with session variables are not inlined
- CALL statement is not supported (usage of direct access to express executor)
- EXECUTE statement is not supported (usage of direct access to express executor)
- memory used by dropped session variables is not released
Implementations of EXPLAIN LET and PREPARE LET statements
are in separate patches (for better readability)
---
doc/src/sgml/catalogs.sgml | 13 +
doc/src/sgml/ddl.sgml | 61 +
doc/src/sgml/func.sgml | 4 +-
doc/src/sgml/glossary.sgml | 5 +-
doc/src/sgml/parallel.sgml | 6 +
doc/src/sgml/plpgsql.sgml | 14 +
doc/src/sgml/ref/allfiles.sgml | 1 +
doc/src/sgml/ref/alter_variable.sgml | 1 +
doc/src/sgml/ref/create_variable.sgml | 5 +-
doc/src/sgml/ref/drop_variable.sgml | 1 +
doc/src/sgml/ref/let.sgml | 96 ++
doc/src/sgml/reference.sgml | 1 +
src/backend/catalog/dependency.c | 5 +
src/backend/catalog/namespace.c | 289 ++++
src/backend/catalog/pg_variable.c | 2 +
src/backend/commands/Makefile | 1 +
src/backend/commands/meson.build | 1 +
src/backend/commands/prepare.c | 10 +
src/backend/commands/session_variable.c | 529 +++++++
src/backend/executor/Makefile | 1 +
src/backend/executor/execExpr.c | 32 +
src/backend/executor/execMain.c | 66 +
src/backend/executor/meson.build | 1 +
src/backend/executor/svariableReceiver.c | 172 +++
src/backend/nodes/nodeFuncs.c | 10 +
src/backend/optimizer/plan/planner.c | 36 +
src/backend/optimizer/plan/setrefs.c | 156 ++-
src/backend/optimizer/prep/prepjointree.c | 3 +
src/backend/optimizer/util/clauses.c | 33 +-
src/backend/parser/analyze.c | 272 +++-
src/backend/parser/gram.y | 39 +-
src/backend/parser/parse_agg.c | 9 +
src/backend/parser/parse_expr.c | 223 ++-
src/backend/parser/parse_func.c | 2 +
src/backend/parser/parse_merge.c | 1 +
src/backend/tcop/dest.c | 7 +
src/backend/tcop/utility.c | 16 +
src/backend/utils/adt/ruleutils.c | 46 +
src/backend/utils/cache/plancache.c | 41 +-
src/backend/utils/fmgr/fmgr.c | 10 +-
src/bin/psql/tab-complete.in.c | 12 +-
src/include/catalog/namespace.h | 1 +
src/include/catalog/pg_variable.h | 9 +
src/include/commands/session_variable.h | 30 +
src/include/executor/svariableReceiver.h | 22 +
src/include/nodes/execnodes.h | 14 +
src/include/nodes/parsenodes.h | 17 +
src/include/nodes/pathnodes.h | 14 +
src/include/nodes/plannodes.h | 9 +
src/include/nodes/primnodes.h | 14 +
src/include/optimizer/planmain.h | 2 +
src/include/parser/kwlist.h | 1 +
src/include/parser/parse_node.h | 3 +
src/include/tcop/cmdtaglist.h | 1 +
src/include/tcop/dest.h | 1 +
src/pl/plpgsql/src/pl_exec.c | 3 +-
.../regress/expected/session_variables.out | 1232 +++++++++++++++++
src/test/regress/sql/session_variables.sql | 883 ++++++++++++
src/tools/pgindent/typedefs.list | 5 +
59 files changed, 4467 insertions(+), 27 deletions(-)
create mode 100644 doc/src/sgml/ref/let.sgml
create mode 100644 src/backend/commands/session_variable.c
create mode 100644 src/backend/executor/svariableReceiver.c
create mode 100644 src/include/commands/session_variable.h
create mode 100644 src/include/executor/svariableReceiver.h
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 8321b453e2c..125d755246a 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9831,6 +9831,19 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcreate_lsn</structfield> <type>pg_lsn</type>
+ </para>
+ <para>
+ LSN of the transaction where the variable was created.
+ <structfield>varcreate_lsn</structfield> and
+ <structfield>oid</structfield> together form the all-time unique
+ identifier (<structfield>oid</structfield> alone is not enough, since
+ object identifiers can get reused).
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>varname</structfield> <type>name</type>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index aca13a9e2e6..147b816370e 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5382,6 +5382,67 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
The session variable holds value in session memory. This value is private
to each session and is released when the session ends.
</para>
+
+ <para>
+ The value of a session variable is set with the SQL statement
+ <command>LET</command>. The value of a session variable can be retrieved
+ with the SQL statement <command>SELECT</command>.
+<programlisting>
+CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
+</programlisting>
+
+ or
+
+<programlisting>
+CREATE VARIABLE public.current_user_id AS integer;
+GRANT SELECT ON VARIABLE public.current_user_id TO PUBLIC;
+LET current_user_id = (SELECT id FROM users WHERE usename = session_user);
+SELECT current_user_id;
+</programlisting>
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a variable's value returns a <literal>NULL</literal>, unless its value has
+ been set to something else in the current session using the
+ <command>LET</command> command. Session variables are not transactional:
+ any changes made to the value of a session variable in a transaction won't
+ be undone if the transaction is rolled back (just like variables in
+ procedural languages). Session variables themselves are persistent, but
+ their values are neither persistent nor shared (like the content of
+ temporary tables).
+ </para>
+
+ <para>
+ Inside a query or an expression, a session variable can be
+ <quote>shadowed</quote> by a column with the same name. Similarly, the
+ name of a function or procedure argument or a PL/pgSQL variable (see
+ <xref linkend="plpgsql-declarations"/>) can shadow a session variable
+ in the routine's body. Such collisions of identifiers can be resolved
+ by using qualified identifiers: Session variables can be qualified with
+ the schema name, columns can use table aliases, routine variables can use
+ block labels, and routine arguments can use the routine name.
+<programlisting>
+CREATE VARIABLE name AS text;
+LET name = 'John';
+
+CREATE TABLE foo(name text);
+INSERT INTO foo VALUES('Alice');
+
+-- variable name is shadowed
+SELECT name FROM foo;
+</programlisting>
+
+ which returns:
+
+<programlisting>
+ name
+-------
+ Alice
+</programlisting>
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index a323215741a..9c12b421041 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25751,8 +25751,8 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
't' for <literal>TABLESPACE</literal>,
'F' for <literal>FOREIGN DATA WRAPPER</literal>,
'S' for <literal>FOREIGN SERVER</literal>,
- or
- 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal>.
+ 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal> or
+ 'V' for <literal>SESSION VARIABLE</literal>.
</para></entry>
</row>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index b921f5a3339..81988f2dfea 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1675,8 +1675,9 @@
<para>
A persistent database object that holds a value in session memory. This
value is private to each session and is released when the session ends.
- Read or write access to session variables is controlled by privileges,
- similar to other database objects.
+ The default value of the session variable is null. Read or write access
+ to session variables is controlled by privileges, similar to other database
+ objects.
</para>
<para>
For more information, see <xref linkend="ddl-session-variables"/>.
diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index 1ce9abf86f5..683dede6adc 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -515,6 +515,12 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
Plan nodes that reference a correlated <literal>SubPlan</literal>.
</para>
</listitem>
+
+ <listitem>
+ <para>
+ Plan nodes that use a session variable.
+ </para>
+ </listitem>
</itemizedlist>
<sect2 id="parallel-labeling">
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index e937491e6b8..1e4c43b8b61 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -6036,6 +6036,20 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE;
</programlisting>
</para>
</sect3>
+
+ <sect3 id="plpgsql-porting-package-variables">
+ <title><command>Packages and package variables</command></title>
+
+ <para>
+ The <application>PL/pgSQL</application> language has no packages, and
+ therefore no package variables or package constants.
+ You can consider translating an Oracle package into a schema in
+ <productname>PostgreSQL</productname>. Package functions and procedures
+ would then become functions and procedures in that schema, and package
+ variables could be translated to session variables in that schema.
+ (see <xref linkend="ddl-session-variables"/>).
+ </para>
+ </sect3>
</sect2>
<sect2 id="plpgsql-porting-appendix">
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index 2f67de3e21b..cc3bd5ab540 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -158,6 +158,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY grant SYSTEM "grant.sgml">
<!ENTITY importForeignSchema SYSTEM "import_foreign_schema.sgml">
<!ENTITY insert SYSTEM "insert.sgml">
+<!ENTITY let SYSTEM "let.sgml">
<!ENTITY listen SYSTEM "listen.sgml">
<!ENTITY load SYSTEM "load.sgml">
<!ENTITY lock SYSTEM "lock.sgml">
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
index 96d2586423e..221a699469b 100644
--- a/doc/src/sgml/ref/alter_variable.sgml
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -173,6 +173,7 @@ ALTER VARIABLE boo SET SCHEMA private;
<simplelist type="inline">
<member><xref linkend="sql-createvariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
</refentry>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index 6e988f2e472..cd9ff63975a 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -120,9 +120,11 @@ CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceab
<title>Examples</title>
<para>
- Create an date session variable <literal>var1</literal>:
+ Create a session variable <literal>var1</literal> of data type date:
<programlisting>
CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
</programlisting>
</para>
@@ -143,6 +145,7 @@ CREATE VARIABLE var1 AS date;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
index 5bdb3560f0b..67988b5fcd8 100644
--- a/doc/src/sgml/ref/drop_variable.sgml
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -111,6 +111,7 @@ DROP VARIABLE var1;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/let.sgml b/doc/src/sgml/ref/let.sgml
new file mode 100644
index 00000000000..00f9bea91fe
--- /dev/null
+++ b/doc/src/sgml/ref/let.sgml
@@ -0,0 +1,96 @@
+<!--
+doc/src/sgml/ref/let.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-let">
+ <indexterm zone="sql-let">
+ <primary>LET</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>changing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>LET</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>LET</refname>
+ <refpurpose>change a session variable's value</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+LET <replaceable class="parameter">session_variable</replaceable> = <replaceable class="parameter">sql_expression</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>LET</command> command assigns a value to the specified session
+ variable.
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">session_variable</replaceable></term>
+ <listitem>
+ <para>
+ The name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">sql_expression</replaceable></term>
+ <listitem>
+ <para>
+ An arbitrary SQL expression. The result must be of a data type that can
+ be cast to the type of the session variable in an assignment.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+<programlisting>
+CREATE VARIABLE myvar AS integer;
+LET myvar = 10;
+LET myvar = (SELECT sum(val) FROM tab);
+</programlisting>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>LET</command> is a <productname>PostgreSQL</productname>
+ extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index 25578f3946c..13e4adc5df3 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -186,6 +186,7 @@
&grant;
&importForeignSchema;
&insert;
+ &let;
&listen;
&load;
&lock;
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 9e0f648b74f..90c9e8bb254 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1864,6 +1864,11 @@ find_expr_references_walker(Node *node,
{
Param *param = (Param *) node;
+ /* a variable parameter depends on the session variable */
+ if (param->paramkind == PARAM_VARIABLE)
+ add_object_address(VariableRelationId, param->paramvarid, 0,
+ context->addrs);
+
/* A parameter must depend on the parameter's datatype */
add_object_address(TypeRelationId, param->paramtype, 0,
context->addrs);
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 4307cad15c7..beafee2a341 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -3497,6 +3497,295 @@ NamesFromList(List *names)
return result;
}
+/* -----
+ * IdentifyVariable - try to find a variable from a list of identifiers
+ *
+ * Returns the OID of the variable found, or InvalidOid.
+ *
+ * "names" is a list of up to four identifiers; possible meanings are:
+ * - variable (searched on the search_path)
+ * - schema.variable
+ * - variable.attribute (searched on the search_path)
+ * - schema.variable.attribute
+ * - database.schema.variable
+ * - database.schema.variable.attribute
+ *
+ * If there is more than one way to identify a variable, "not_unique" will be
+ * set to true.
+ *
+ * Unless "noerror" is true, an error is raised if there are more than four
+ * identifiers in the list, or if the named database is not the current one.
+ * This is useful if we want to identify a shadowed variable.
+ *
+ * If an attribute is identified, it is stored in "attrname", otherwise the
+ * parameter is set to NULL.
+ *
+ * The identified session variable will be locked with an AccessShareLock.
+ * -----
+ */
+Oid
+IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror)
+{
+ Oid varid = InvalidOid;
+ Oid old_varid = InvalidOid;
+ uint64 inval_count;
+ bool retry = false;
+
+ /*
+ * DDL operations can change the results of a name lookup. Since all such
+ * operations will generate invalidation messages, we keep track of
+ * whether any such messages show up while we're performing the operation,
+ * and retry until either (1) no more invalidation messages show up or (2)
+ * the answer doesn't change.
+ */
+ for (;;)
+ {
+ Node *field1 = NULL;
+ Node *field2 = NULL;
+ Node *field3 = NULL;
+ Node *field4 = NULL;
+ char *a = NULL;
+ char *b = NULL;
+ char *c = NULL;
+ char *d = NULL;
+ Oid varoid_without_attr = InvalidOid;
+ Oid varoid_with_attr = InvalidOid;
+
+ *not_unique = false;
+ *attrname = NULL;
+ varid = InvalidOid;
+
+ inval_count = SharedInvalidMessageCounter;
+
+ switch (list_length(names))
+ {
+ case 1:
+ field1 = linitial(names);
+
+ Assert(IsA(field1, String));
+
+ varid = LookupVariable(NULL, strVal(field1), true);
+ break;
+
+ case 2:
+ field1 = linitial(names);
+ field2 = lsecond(names);
+
+ Assert(IsA(field1, String));
+ a = strVal(field1);
+
+ if (IsA(field2, String))
+ {
+ /* when both fields are of string type */
+ b = strVal(field2);
+
+ /*
+ * a.b can mean "schema"."variable" or
+ * "variable"."attribute". Check both variants, and
+ * returns InvalidOid with not_unique flag, when both
+ * interpretations are possible.
+ */
+ varoid_without_attr = LookupVariable(a, b, true);
+ varoid_with_attr = LookupVariable(NULL, a, true);
+ }
+ else
+ {
+ /* the last field of list can be star too */
+ Assert(IsA(field2, A_Star));
+
+ /*
+ * The syntax ident.* is used only by relation aliases,
+ * and then this identifier cannot be a reference to
+ * session variable.
+ */
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = b;
+ varid = varoid_with_attr;
+ }
+ break;
+
+ case 3:
+ {
+ bool field1_is_catalog = false;
+
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+
+ if (IsA(field3, String))
+ {
+ c = strVal(field3);
+
+ /*
+ * a.b.c can mean catalog.schema.variable or
+ * schema.variable.attribute.
+ *
+ * Check both variants, and set not_unique flag, when
+ * both interpretations are possible.
+ *
+ * When third node is star, only possible
+ * interpretation is schema.variable.*, but this
+ * pattern is not supported now.
+ */
+ varoid_with_attr = LookupVariable(a, b, true);
+
+ /*
+ * check pattern catalog.schema.variable only when
+ * there is possibility to success.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) == 0)
+ {
+ field1_is_catalog = true;
+ varoid_without_attr = LookupVariable(b, c, true);
+ }
+ }
+ else
+ {
+ Assert(IsA(field3, A_Star));
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = c;
+ varid = varoid_with_attr;
+ }
+
+ /*
+ * When we didn't find variable, we can (when it is
+ * allowed) raise cross-database reference error.
+ */
+ if (!OidIsValid(varid) && !noerror && !field1_is_catalog)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+ break;
+
+ case 4:
+ {
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+ field4 = lfourth(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+ Assert(IsA(field3, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+ c = strVal(field3);
+
+ /*
+ * In this case, "a" is used as catalog name - check it.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) != 0)
+ {
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+
+ if (IsA(field4, String))
+ {
+ d = strVal(field4);
+ }
+ else
+ {
+ Assert(IsA(field4, A_Star));
+ return InvalidOid;
+ }
+
+ *attrname = d;
+ varid = LookupVariable(b, c, true);
+ }
+ break;
+
+ default:
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper qualified name (too many dotted names): %s",
+ NameListToString(names))));
+ return InvalidOid;
+ }
+
+ /*
+ * If, upon retry, we get back the same OID we did last time, then the
+ * invalidation messages we processed did not change the final answer.
+ * So we're done.
+ *
+ * If we got a different OID, we've locked the variable that used to
+ * have this name rather than the one that does now. So release the
+ * lock.
+ */
+ if (retry)
+ {
+ if (old_varid == varid)
+ break;
+
+ if (OidIsValid(old_varid))
+ UnlockDatabaseObject(VariableRelationId, old_varid, 0, AccessShareLock);
+ }
+
+ /*
+ * Lock the variable. This will also accept any pending invalidation
+ * messages. If we got back InvalidOid, indicating not found, then
+ * there's nothing to lock, but we accept invalidation messages
+ * anyway, to flush any negative catcache entries that may be
+ * lingering.
+ */
+ if (!OidIsValid(varid))
+ AcceptInvalidationMessages();
+ else
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ /*
+ * If no invalidation message were processed, we're done!
+ */
+ if (inval_count == SharedInvalidMessageCounter)
+ break;
+
+ retry = true;
+ old_varid = varid;
+ varid = InvalidOid;
+ }
+
+ return varid;
+}
+
/*
* DeconstructQualifiedName
* Given a possibly-qualified name expressed as a list of String nodes,
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 29d967a2d5b..bb445e9434b 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -26,6 +26,7 @@
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
+#include "utils/pg_lsn.h"
#include "utils/syscache.h"
static ObjectAddress create_variable(const char *varName,
@@ -101,6 +102,7 @@ create_variable(const char *varName,
varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varcreate_lsn - 1] = LSNGetDatum(GetXLogInsertRecPtr());
values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile
index 85cfea6fd71..55de062c205 100644
--- a/src/backend/commands/Makefile
+++ b/src/backend/commands/Makefile
@@ -52,6 +52,7 @@ OBJS = \
schemacmds.o \
seclabel.o \
sequence.o \
+ session_variable.o \
statscmds.o \
subscriptioncmds.o \
tablecmds.o \
diff --git a/src/backend/commands/meson.build b/src/backend/commands/meson.build
index ce8d1ab8bac..ba2891e037b 100644
--- a/src/backend/commands/meson.build
+++ b/src/backend/commands/meson.build
@@ -40,6 +40,7 @@ backend_sources += files(
'schemacmds.c',
'seclabel.c',
'sequence.c',
+ 'session_variable.c',
'statscmds.c',
'subscriptioncmds.c',
'tablecmds.c',
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 4d68d4d25c7..2d04c71a148 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -340,6 +340,16 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
i++;
}
+ /*
+ * The arguments of EXECUTE are evaluated by a direct expression
+ * executor call. This mode doesn't support session variables yet.
+ * It will be enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
/* Prepare the expressions for execution */
exprstates = ExecPrepareExprList(params, estate);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
new file mode 100644
index 00000000000..d2891a1dcb7
--- /dev/null
+++ b/src/backend/commands/session_variable.c
@@ -0,0 +1,529 @@
+/*-------------------------------------------------------------------------
+ *
+ * session_variable.c
+ * session variable creation/manipulation commands
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/commands/session_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "rewrite/rewriteHandler.h"
+#include "storage/lmgr.h"
+#include "storage/proc.h"
+#include "tcop/tcopprot.h"
+#include "utils/builtins.h"
+#include "utils/datum.h"
+#include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/snapmgr.h"
+#include "utils/syscache.h"
+
+/*
+ * The values of session variables are stored in the backend's private memory
+ * in the dedicated memory context SVariableMemoryContext in binary format.
+ * They are stored in the "sessionvars" hash table, whose key is the OID of the
+ * variable. However, the OID is not good enough to identify a session
+ * variable: concurrent sessions could drop the session variable and create a
+ * new one, which could be assigned the same OID. To ensure that the values
+ * stored in memory and the catalog definition match, we also keep track of
+ * the "create_lsn". Before any access to the variable values, we need to
+ * check if the LSN stored in memory matches the LSN in the catalog. If there
+ * is a mismatch between the LSNs, or if the OID is not present in pg_variable
+ * at all, the value stored in memory is released.
+ */
+typedef struct SVariableData
+{
+ Oid varid; /* pg_variable OID of the variable (hash key) */
+ XLogRecPtr create_lsn;
+
+ bool isnull;
+ Datum value;
+
+ Oid typid;
+ int16 typlen;
+ bool typbyval;
+
+ bool is_domain;
+
+ /*
+ * domain_check_extra holds cached domain metadata. This "extra" is
+ * usually stored in fn_mcxt. We do not have access to that memory context
+ * for session variables, but we can use TopTransactionContext instead.
+ * A fresh value is forced when we detect we are in a different transaction
+ * (the local transaction ID differs from domain_check_extra_lxid).
+ */
+ void *domain_check_extra;
+ LocalTransactionId domain_check_extra_lxid;
+
+ /*
+ * Stored value and type description can be outdated when we receive a
+ * sinval message. We then have to check if the stored data are still
+ * trustworthy.
+ */
+ bool is_valid;
+
+ uint32 hashvalue; /* used for pairing sinval message */
+} SVariableData;
+
+typedef SVariableData *SVariable;
+
+static HTAB *sessionvars = NULL; /* hash table for session variables */
+
+static MemoryContext SVariableMemoryContext = NULL;
+
+/*
+ * Callback function for session variable invalidation.
+ */
+static void
+pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
+
+ Assert(sessionvars);
+
+ /*
+ * If the hashvalue is not specified, we have to recheck all currently
+ * used session variables. Since we can't tell the exact session variable
+ * from its hashvalue, we have to iterate over all items in the hash bucket.
+ */
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (hashvalue == 0 || svar->hashvalue == hashvalue)
+ {
+ svar->is_valid = false;
+ }
+ }
+}
+
+/*
+ * Release stored value, free memory
+ */
+static void
+free_session_variable_value(SVariable svar)
+{
+ /* clean the current value */
+ if (!svar->isnull)
+ {
+ if (!svar->typbyval)
+ pfree(DatumGetPointer(svar->value));
+
+ svar->isnull = true;
+ }
+
+ svar->value = (Datum) 0;
+}
+
+/*
+ * Returns true when the entry in pg_variable is consistent with the given
+ * session variable.
+ */
+static bool
+is_session_variable_valid(SVariable svar)
+{
+ HeapTuple tp;
+ bool result = false;
+
+ Assert(OidIsValid(svar->varid));
+
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ /*
+ * The OID alone is not enough as an unique identifier, because OID
+ * values get recycled, and a new session variable could have got
+ * the same OID. We do a second check against the 64-bit LSN when
+ * the variable was created.
+ */
+ if (svar->create_lsn == ((Form_pg_variable) GETSTRUCT(tp))->varcreate_lsn)
+ result = true;
+
+ ReleaseSysCache(tp);
+ }
+
+ return result;
+}
+
+/*
+ * Initialize attributes cached in "svar"
+ */
+static void
+setup_session_variable(SVariable svar, Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ Assert(OidIsValid(varid));
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ svar->varid = varid;
+ svar->create_lsn = varform->varcreate_lsn;
+
+ svar->typid = varform->vartype;
+
+ get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval);
+
+ svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
+ svar->domain_check_extra = NULL;
+ svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+
+ svar->isnull = true;
+ svar->value = (Datum) 0;
+
+ svar->is_valid = true;
+
+ svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ ReleaseSysCache(tup);
+}
+
+/*
+ * Assign a new value to the session variable. It is copied to
+ * SVariableMemoryContext if necessary.
+ *
+ * If any error happens, the existing value won't be modified.
+ */
+static void
+set_session_variable(SVariable svar, Datum value, bool isnull)
+{
+ Datum newval;
+ SVariableData locsvar,
+ *_svar;
+
+ Assert(svar);
+ Assert(!isnull || value == (Datum) 0);
+
+ /*
+ * Use typbyval, typbylen from session variable only when they are
+ * trustworthy (the invalidation message was not accepted for this
+ * variable). If the variable might be invalid, force setup.
+ *
+ * Do not overwrite the passed session variable until we can be certain
+ * that no error can be thrown.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(&locsvar, svar->varid);
+ _svar = &locsvar;
+ }
+ else
+ _svar = svar;
+
+ if (!isnull)
+ {
+ MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
+
+ newval = datumCopy(value, _svar->typbyval, _svar->typlen);
+
+ MemoryContextSwitchTo(oldcxt);
+ }
+ else
+ newval = value;
+
+ free_session_variable_value(svar);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ svar->varid);
+
+ /* no more error expected, so we can overwrite the old variable now */
+ if (svar != _svar)
+ memcpy(svar, _svar, sizeof(SVariableData));
+
+ svar->value = newval;
+ svar->isnull = isnull;
+}
+
+/*
+ * Create the hash table for storing session variables.
+ */
+static void
+create_sessionvars_hashtables(void)
+{
+ HASHCTL vars_ctl;
+
+ Assert(!sessionvars);
+
+ if (!SVariableMemoryContext)
+ {
+ /* read sinval messages */
+ CacheRegisterSyscacheCallback(VARIABLEOID,
+ pg_variable_cache_callback,
+ (Datum) 0);
+
+ /* we need our own long-lived memory context */
+ SVariableMemoryContext =
+ AllocSetContextCreate(TopMemoryContext,
+ "session variables",
+ ALLOCSET_START_SMALL_SIZES);
+ }
+
+ memset(&vars_ctl, 0, sizeof(vars_ctl));
+ vars_ctl.keysize = sizeof(Oid);
+ vars_ctl.entrysize = sizeof(SVariableData);
+ vars_ctl.hcxt = SVariableMemoryContext;
+
+ sessionvars = hash_create("Session variables", 64, &vars_ctl,
+ HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+}
+
+/*
+ * Search a session variable in the hash table given its OID. If it
+ * doesn't exist, then insert it there.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the
+ * session variable until the end of the transaction.
+ */
+static SVariable
+get_session_variable(Oid varid)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect the used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (found)
+ {
+ if (!svar->is_valid)
+ {
+ /*
+ * If there was an invalidation message, the variable might still be
+ * valid, but we have to check with the system catalog.
+ */
+ if (is_session_variable_valid(svar))
+ svar->is_valid = true;
+ else
+ /* if the value cannot be validated, we have to discard it */
+ free_session_variable_value(svar);
+ }
+ }
+ else
+ svar->is_valid = false;
+
+ /*
+ * Force setup for not yet initialized variables or variables that cannot
+ * be validated.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ varid);
+ }
+
+ /* ensure the returned data is still of the correct domain */
+ if (svar->is_domain)
+ {
+ /*
+ * Store "extra" for domain_check() in TopTransactionContext. When we
+ * are in a new transaction, domain_check_extra cache is not valid any
+ * more.
+ */
+ if (svar->domain_check_extra_lxid != MyProc->vxid.lxid)
+ svar->domain_check_extra = NULL;
+
+ domain_check(svar->value, svar->isnull,
+ svar->typid, &svar->domain_check_extra,
+ TopTransactionContext);
+
+ svar->domain_check_extra_lxid = MyProc->vxid.lxid;
+ }
+
+ return svar;
+}
+
+/*
+ * Store the given value in a session variable in the cache.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the session
+ * variable until the end of the transaction.
+ */
+void
+SetSessionVariable(Oid varid, Datum value, bool isNull)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (!found)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ varid);
+ }
+
+ /* if this fails, it won't change the stored value */
+ set_session_variable(svar, value, isNull);
+}
+
+/*
+ * Returns a copy of the value stored in a variable.
+ */
+static inline Datum
+copy_session_variable_value(SVariable svar, bool *isNull)
+{
+ Datum value;
+
+ /* force copy of non NULL value */
+ if (!svar->isnull)
+ {
+ value = datumCopy(svar->value, svar->typbyval, svar->typlen);
+ *isNull = false;
+ }
+ else
+ {
+ value = (Datum) 0;
+ *isNull = true;
+ }
+
+ return value;
+}
+
+/*
+ * Returns a copy of the value of the session variable (in the current memory
+ * context). The caller is responsible for permission checks.
+ */
+Datum
+GetSessionVariable(Oid varid, bool *isNull)
+{
+ SVariable svar;
+
+ svar = get_session_variable(varid);
+
+ /*
+ * Although "svar" is freshly validated in this point, svar->is_valid can
+ * be false, if an invalidation message was processed during the domain check.
+ * But the variable and all its dependencies are locked now, so we don't need
+ * to repeat the validation.
+ */
+ return copy_session_variable_value(svar, isNull);
+}
+
+/*
+ * Assign the result of the evaluated expression to the session variable
+ */
+void
+ExecuteLetStmt(ParseState *pstate,
+ LetStmt *stmt,
+ ParamListInfo params,
+ QueryEnvironment *queryEnv,
+ QueryCompletion *qc)
+{
+ Query *query = castNode(Query, stmt->query);
+ List *rewritten;
+ DestReceiver *dest;
+ AclResult aclresult;
+ PlannedStmt *plan;
+ QueryDesc *queryDesc;
+ Oid varid = query->resultVariable;
+
+ Assert(OidIsValid(varid));
+
+ /* do we have permission to write to the session variable? */
+ aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid));
+
+ /* create a dest receiver for LET */
+ dest = CreateVariableDestReceiver(varid);
+
+ /* run the query rewriter */
+ query = copyObject(query);
+
+ rewritten = QueryRewrite(query);
+
+ Assert(list_length(rewritten) == 1);
+
+ query = linitial_node(Query, rewritten);
+ Assert(query->commandType == CMD_SELECT);
+
+ /* plan the query */
+ plan = pg_plan_query(query, pstate->p_sourcetext,
+ CURSOR_OPT_PARALLEL_OK, params);
+
+ /*
+ * Use a snapshot with an updated command ID to ensure this query sees the
+ * results of any previously executed queries. (This could only matter if
+ * the planner executed an allegedly-stable function that changed the
+ * database contents, but let's do it anyway to be parallel to the EXPLAIN
+ * code path.)
+ */
+ PushCopiedSnapshot(GetActiveSnapshot());
+ UpdateActiveSnapshotCommandId();
+
+ /* create a QueryDesc, redirecting output to our tuple receiver */
+ queryDesc = CreateQueryDesc(plan, NULL, pstate->p_sourcetext,
+ GetActiveSnapshot(), InvalidSnapshot,
+ dest, params, queryEnv, 0);
+
+ /* call ExecutorStart to prepare the plan for execution */
+ ExecutorStart(queryDesc, 0);
+
+ /*
+ * Run the plan to completion. The result should be only one row. To
+ * check if there are too many result rows, we try to fetch two.
+ */
+ ExecutorRun(queryDesc, ForwardScanDirection, 2L);
+
+ /* save the rowcount if we're given a QueryCompletion to fill */
+ if (qc)
+ SetQueryCompletion(qc, CMDTAG_LET, queryDesc->estate->es_processed);
+
+ /* and clean up */
+ ExecutorFinish(queryDesc);
+ ExecutorEnd(queryDesc);
+
+ FreeQueryDesc(queryDesc);
+
+ PopActiveSnapshot();
+}
diff --git a/src/backend/executor/Makefile b/src/backend/executor/Makefile
index 11118d0ce02..71248a34f26 100644
--- a/src/backend/executor/Makefile
+++ b/src/backend/executor/Makefile
@@ -76,6 +76,7 @@ OBJS = \
nodeWindowAgg.o \
nodeWorktablescan.o \
spi.o \
+ svariableReceiver.o \
tqueue.o \
tstoreReceiver.o
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index f1569879b52..e4e9de335b5 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -1041,6 +1041,38 @@ ExecInitExprRec(Expr *node, ExprState *state,
scratch.d.param.paramtype = param->paramtype;
ExprEvalPushStep(state, &scratch);
break;
+
+ case PARAM_VARIABLE:
+ {
+ int es_num_session_variables = 0;
+ SessionVariableValue *es_session_variables = NULL;
+ SessionVariableValue *var;
+
+ if (state->parent && state->parent->state)
+ {
+ es_session_variables = state->parent->state->es_session_variables;
+ es_num_session_variables = state->parent->state->es_num_session_variables;
+ }
+
+ Assert(es_session_variables);
+
+ /* parameter sanity checks */
+ if (param->paramid >= es_num_session_variables)
+ elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
+
+ var = &es_session_variables[param->paramid];
+
+ /*
+ * In this case, pass the value like a
+ * constant.
+ */
+ scratch.opcode = EEOP_CONST;
+ scratch.d.constval.value = var->value;
+ scratch.d.constval.isnull = var->isnull;
+ ExprEvalPushStep(state, &scratch);
+ }
+ break;
+
case PARAM_EXTERN:
/*
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 0493b7d5365..67e0b9ba2ac 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -43,7 +43,9 @@
#include "access/xact.h"
#include "catalog/namespace.h"
#include "catalog/partition.h"
+#include "catalog/pg_variable.h"
#include "commands/matview.h"
+#include "commands/session_variable.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/execPartition.h"
@@ -203,6 +205,70 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
Assert(queryDesc->sourceText != NULL);
estate->es_sourceText = queryDesc->sourceText;
+ /*
+ * The executor doesn't work with session variables directly. Values of
+ * related session variables are copied to a dedicated array, and this array
+ * is passed to the executor. This array is stable "snapshot" of values of
+ * used session variables. There are three benefits of this strategy:
+ *
+ * - consistency with external parameters and plpgsql variables,
+ *
+ * - session variables can be parallel safe,
+ *
+ * - we don't need make fresh copy for any read of session variable
+ * (this is necessary because the internally the session variable can
+ * be changed inside query execution time, and then a reference to
+ * previously returned value can be corrupted).
+ */
+ if (queryDesc->plannedstmt->sessionVariables)
+ {
+ int nSessionVariables;
+ int i = 0;
+
+ /*
+ * In this case, the query uses session variables, but we have to
+ * prepare the array with passed values (of used session variables)
+ * first.
+ */
+ Assert(!IsParallelWorker());
+ nSessionVariables = list_length(queryDesc->plannedstmt->sessionVariables);
+
+ /* create the array used for passing values of used session variables */
+ estate->es_session_variables = (SessionVariableValue *)
+ palloc(nSessionVariables * sizeof(SessionVariableValue));
+
+ /* fill the array */
+ foreach_oid(varid, queryDesc->plannedstmt->sessionVariables)
+ {
+ /*
+ * Permission check should be executed on all explicitly used
+ * variables in the query. For implicitly used variable
+ * (like base node of assignment indirect) we cannot do permission
+ * check, because we need read the value (and user can have
+ * only UPDATE variable). In this case the permission check
+ * is executed in write time.
+ */
+ if (varid != queryDesc->plannedstmt->exclSelectPermCheckVarid)
+ {
+ AclResult aclresult;
+
+ aclresult = object_aclcheck(VariableRelationId, varid,
+ GetUserId(), ACL_SELECT);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE,
+ get_session_variable_name(varid));
+ }
+
+ estate->es_session_variables[i].value =
+ GetSessionVariable(varid,
+ &estate->es_session_variables[i].isnull);
+
+ i++;
+ }
+
+ estate->es_num_session_variables = nSessionVariables;
+ }
+
/*
* Fill in the query environment, if any, from queryDesc.
*/
diff --git a/src/backend/executor/meson.build b/src/backend/executor/meson.build
index 2cea41f8771..491092fcc4c 100644
--- a/src/backend/executor/meson.build
+++ b/src/backend/executor/meson.build
@@ -64,6 +64,7 @@ backend_sources += files(
'nodeWindowAgg.c',
'nodeWorktablescan.c',
'spi.c',
+ 'svariableReceiver.c',
'tqueue.c',
'tstoreReceiver.c',
)
diff --git a/src/backend/executor/svariableReceiver.c b/src/backend/executor/svariableReceiver.c
new file mode 100644
index 00000000000..c6163fb36f6
--- /dev/null
+++ b/src/backend/executor/svariableReceiver.c
@@ -0,0 +1,172 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.c
+ * An implementation of DestReceiver that stores the result value in
+ * a session variable.
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/executor/svariableReceiver.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "miscadmin.h"
+
+#include "access/detoast.h"
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "storage/lock.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+/*
+ * This DestReceiver is used by the LET command for storing the result to a
+ * session variable. The result has to have only one tuple with only one
+ * non-deleted attribute. The row counter (field "rows") is incremented
+ * after receiving a row, and an error is raised when there are no rows or
+ * there are more than one received rows. A received tuple cannot to have
+ * deleted attributes. The value is detoasted before storing it in the
+ * session variable.
+ */
+typedef struct
+{
+ DestReceiver pub;
+ Oid varid;
+ bool need_detoast; /* do we need to detoast the attribute? */
+ int rows; /* row counter */
+} SVariableState;
+
+/*
+ * Prepare to receive tuples from executor.
+ */
+static void
+svariableStartupReceiver(DestReceiver *self, int operation, TupleDesc typeinfo)
+{
+ SVariableState *myState = (SVariableState *) self;
+ LOCKTAG locktag PG_USED_FOR_ASSERTS_ONLY;
+ Form_pg_attribute attr;
+ Oid typid PG_USED_FOR_ASSERTS_ONLY;
+ Oid collid PG_USED_FOR_ASSERTS_ONLY;
+ int32 typmod PG_USED_FOR_ASSERTS_ONLY;
+
+ Assert(myState->pub.mydest == DestVariable);
+ Assert(OidIsValid(myState->varid));
+ Assert(SearchSysCacheExists1(VARIABLEOID, myState->varid));
+ Assert(typeinfo->natts == 1);
+
+#ifdef USE_ASSERT_CHECKING
+
+ SET_LOCKTAG_OBJECT(locktag,
+ MyDatabaseId,
+ VariableRelationId,
+ myState->varid,
+ 0);
+
+ Assert(LockHeldByMe(&locktag, AccessShareLock, false));
+
+#endif
+
+ attr = TupleDescAttr(typeinfo, 0);
+
+ Assert(!attr->attisdropped);
+
+#ifdef USE_ASSERT_CHECKING
+
+ get_session_variable_type_typmod_collid(myState->varid,
+ &typid,
+ &typmod,
+ &collid);
+
+ Assert(attr->atttypid == typid);
+ Assert(attr->atttypmod < 0 || attr->atttypmod == typmod);
+
+#endif
+
+ myState->need_detoast = attr->attlen == -1;
+ myState->rows = 0;
+}
+
+/*
+ * Receive a tuple from the executor and store it in the session variable.
+ */
+static bool
+svariableReceiveSlot(TupleTableSlot *slot, DestReceiver *self)
+{
+ SVariableState *myState = (SVariableState *) self;
+ Datum value;
+ bool isnull;
+ bool freeval = false;
+
+ /* make sure the tuple is fully deconstructed */
+ slot_getallattrs(slot);
+
+ value = slot->tts_values[0];
+ isnull = slot->tts_isnull[0];
+
+ if (myState->need_detoast && !isnull && VARATT_IS_EXTERNAL(DatumGetPointer(value)))
+ {
+ value = PointerGetDatum(detoast_external_attr((struct varlena *)
+ DatumGetPointer(value)));
+ freeval = true;
+ }
+
+ myState->rows += 1;
+
+ if (myState->rows > 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_TOO_MANY_ROWS),
+ errmsg("expression returned more than one row")));
+
+ SetSessionVariable(myState->varid, value, isnull);
+
+ if (freeval)
+ pfree(DatumGetPointer(value));
+
+ return true;
+}
+
+/*
+ * Clean up at end of the executor run
+ */
+static void
+svariableShutdownReceiver(DestReceiver *self)
+{
+ if (((SVariableState *) self)->rows == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_NO_DATA_FOUND),
+ errmsg("expression returned no rows")));
+}
+
+/*
+ * Destroy the receiver when we are done with it
+ */
+static void
+svariableDestroyReceiver(DestReceiver *self)
+{
+ pfree(self);
+}
+
+/*
+ * Initially create a DestReceiver object.
+ */
+DestReceiver *
+CreateVariableDestReceiver(Oid varid)
+{
+ SVariableState *self = (SVariableState *) palloc0(sizeof(SVariableState));
+
+ self->pub.receiveSlot = svariableReceiveSlot;
+ self->pub.rStartup = svariableStartupReceiver;
+ self->pub.rShutdown = svariableShutdownReceiver;
+ self->pub.rDestroy = svariableDestroyReceiver;
+ self->pub.mydest = DestVariable;
+
+ self->varid = varid;
+
+ return (DestReceiver *) self;
+}
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f1..d8fc3d9fa69 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4375,6 +4375,16 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_LetStmt:
+ {
+ LetStmt *stmt = (LetStmt *) node;
+
+ if (WALK(stmt->target))
+ return true;
+ if (WALK(stmt->query))
+ return true;
+ }
+ break;
case T_PLAssignStmt:
{
PLAssignStmt *stmt = (PLAssignStmt *) node;
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index a4d523dcb0f..c7e7977a269 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -334,6 +334,21 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
glob->lastPlanNodeId = 0;
glob->transientPlan = false;
glob->dependsOnRole = false;
+ glob->sessionVariables = NIL;
+
+ /*
+ * The (session) result variable should be stored to global, because
+ * it is not set in subquery. When this variable is used other than
+ * in base node of assignment indirection, we need to check the access
+ * rights (and then we need to detect this situation). The variable used
+ * like base node cannot be different than target (result) variable.
+ * Because we know the result variable before planner invocation, we
+ * can simply search of usage just this variable, and we don't need to
+ * to wait until the end of planning when we know basenodeSessionVarid.
+ */
+ glob->resultVariable = parse->resultVariable;
+ glob->basenodeSessionVarid = InvalidOid;
+ glob->basenodeSessionVarSelectCheck = false;
/*
* Assess whether it's feasible to use parallel mode for this query. We
@@ -571,6 +586,20 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
result->paramExecTypes = glob->paramExecTypes;
/* utilityStmt should be null, but we might as well copy it */
result->utilityStmt = parse->utilityStmt;
+
+ result->sessionVariables = glob->sessionVariables;
+
+ /*
+ * The session variable used (and only used) like base node
+ * for assignemnt indirection should be excluded from permission
+ * check.
+ */
+ if (OidIsValid(glob->basenodeSessionVarid) &&
+ (!glob->basenodeSessionVarSelectCheck))
+ result->exclSelectPermCheckVarid = glob->basenodeSessionVarid;
+ else
+ result->exclSelectPermCheckVarid = InvalidOid;
+
result->stmt_location = parse->stmt_location;
result->stmt_len = parse->stmt_len;
@@ -749,6 +778,13 @@ subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root,
*/
pull_up_subqueries(root);
+ /*
+ * Check if some subquery uses a session variable. The flag
+ * hasSessionVariables should be true if the query or some subquery uses a
+ * session variable.
+ */
+ pull_up_has_session_variables(root);
+
/*
* If this is a simple UNION ALL query, flatten it into an appendrel. We
* do this now because it requires applying pull_up_subqueries to the leaf
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 999a5a8ab5a..dc2caa520f7 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -210,6 +210,9 @@ static List *set_returning_clause_references(PlannerInfo *root,
static List *set_windowagg_runcondition_references(PlannerInfo *root,
List *runcondition,
Plan *plan);
+static bool pull_up_has_session_variables_walker(Node *node,
+ PlannerInfo *root);
+static void record_plan_variable_dependency(PlannerInfo *root, Oid varid);
/*****************************************************************************
@@ -1315,6 +1318,50 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
return plan;
}
+/*
+ * Search usage of session variables in subqueries
+ */
+void
+pull_up_has_session_variables(PlannerInfo *root)
+{
+ Query *query = root->parse;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ }
+ else
+ {
+ (void) query_tree_walker(query,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+}
+
+static bool
+pull_up_has_session_variables_walker(Node *node, PlannerInfo *root)
+{
+ if (node == NULL)
+ return false;
+ if (IsA(node, Query))
+ {
+ Query *query = (Query *) node;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ return false;
+ }
+
+ /* recurse into subselects */
+ return query_tree_walker((Query *) node,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+ return expression_tree_walker(node, pull_up_has_session_variables_walker,
+ (void *) root);
+}
+
/*
* set_indexonlyscan_references
* Do set_plan_references processing on an IndexOnlyScan
@@ -2015,8 +2062,9 @@ copyVar(Var *var)
* This is code that is common to all variants of expression-fixing.
* We must look up operator opcode info for OpExpr and related nodes,
* add OIDs from regclass Const nodes into root->glob->relationOids, and
- * add PlanInvalItems for user-defined functions into root->glob->invalItems.
- * We also fill in column index lists for GROUPING() expressions.
+ * add PlanInvalItems for user-defined functions and session variables into
+ * root->glob->invalItems. We also fill in column index lists for GROUPING()
+ * expressions.
*
* We assume it's okay to update opcode info in-place. So this could possibly
* scribble on the planner's input data structures, but it's OK.
@@ -2106,6 +2154,13 @@ fix_expr_common(PlannerInfo *root, Node *node)
g->cols = cols;
}
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ record_plan_variable_dependency(root, p->paramvarid);
+ }
}
/*
@@ -2115,6 +2170,10 @@ fix_expr_common(PlannerInfo *root, Node *node)
* If it's a PARAM_MULTIEXPR, replace it with the appropriate Param from
* root->multiexpr_params; otherwise no change is needed.
* Just for paranoia's sake, we make a copy of the node in either case.
+ *
+ * If it's a PARAM_VARIABLE, then we collect used session variables in
+ * the list root->glob->sessionVariable. Also, assign the parameter's
+ * "paramid" to the parameter's position in that list.
*/
static Node *
fix_param_node(PlannerInfo *root, Param *p)
@@ -2133,6 +2192,62 @@ fix_param_node(PlannerInfo *root, Param *p)
elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid);
return copyObject(list_nth(params, colno - 1));
}
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ int n = 0;
+ bool found = false;
+
+ /* we will modify object */
+ p = (Param *) copyObject(p);
+
+ /*
+ * Now, we can actualize list of session variables, and we can
+ * complete paramid parameter.
+ */
+ foreach_oid(varid, root->glob->sessionVariables)
+ {
+ if (varid == p->paramvarid)
+ {
+ p->paramid = n;
+ found = true;
+ break;
+ }
+ n += 1;
+ }
+
+ if (!found)
+ {
+ root->glob->sessionVariables = lappend_oid(root->glob->sessionVariables,
+ p->paramvarid);
+ p->paramid = n;
+ }
+
+ /*
+ * We do SELECT permission check of all variables used by
+ * the query excluding the variable that is used only as base node
+ * of assignment indirection. The variable id assigned to this param
+ * should be same like resultVariable id, and this param should be
+ * used only once in query. When the variable is referenced by any
+ * other param, we should to do SELECT permission check for this variable
+ * too.
+ */
+ if (p->parambasenode)
+ {
+ Assert(!OidIsValid(root->glob->basenodeSessionVarid));
+ Assert(root->glob->resultVariable == p->paramvarid);
+
+ root->glob->basenodeSessionVarid = p->paramvarid;
+ }
+ else
+ {
+ if (p->paramvarid == root->glob->resultVariable)
+ root->glob->basenodeSessionVarSelectCheck = true;
+ }
+
+ return (Node *) p;
+ }
+
return (Node *) copyObject(p);
}
@@ -2194,7 +2309,10 @@ fix_alternative_subplan(PlannerInfo *root, AlternativeSubPlan *asplan,
* replacing Aggref nodes that should be replaced by initplan output Params,
* choosing the best implementation for AlternativeSubPlans,
* looking up operator opcode info for OpExpr and related nodes,
- * and adding OIDs from regclass Const nodes into root->glob->relationOids.
+ * adding OIDs from regclass Const nodes into root->glob->relationOids,
+ * assigning paramvarid to PARAM_VARIABLE params, and collecting the
+ * OIDs of session variables in the root->glob->sessionVariables list
+ * (paramvarid is the position of the session variable in this list).
*
* 'node': the expression to be modified
* 'rtoffset': how much to increment varnos by
@@ -2216,7 +2334,8 @@ fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec)
root->multiexpr_params != NIL ||
root->glob->lastPHId != 0 ||
root->minmax_aggs != NIL ||
- root->hasAlternativeSubPlans)
+ root->hasAlternativeSubPlans ||
+ root->hasSessionVariables)
{
return fix_scan_expr_mutator(node, &context);
}
@@ -3609,6 +3728,25 @@ record_plan_type_dependency(PlannerInfo *root, Oid typid)
}
}
+/*
+ * Record dependency on a session variable. The variable can be used as a
+ * session variable in an expression list, or as the target of a LET statement.
+ */
+static void
+record_plan_variable_dependency(PlannerInfo *root, Oid varid)
+{
+ PlanInvalItem *inval_item = makeNode(PlanInvalItem);
+
+ /* paramid is still session variable id */
+ inval_item->cacheId = VARIABLEOID;
+ inval_item->hashValue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ /* append this variable to global, register dependency */
+ root->glob->invalItems = lappend(root->glob->invalItems,
+ inval_item);
+}
+
/*
* extract_query_dependencies
* Given a rewritten, but not yet planned, query or queries
@@ -3694,9 +3832,9 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
}
/*
- * Ignore other utility statements, except those (such as EXPLAIN)
- * that contain a parsed-but-not-planned query. For those, we
- * just need to transfer our attention to the contained query.
+ * Ignore other utility statements, except those (such as EXPLAIN
+ * or LET) that contain a parsed-but-not-planned query. For those,
+ * we just need to transfer our attention to the contained query.
*/
query = UtilityContainsQuery(query->utilityStmt);
if (query == NULL)
@@ -3719,6 +3857,10 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
lappend_oid(context->glob->relationOids, rte->relid);
}
+ /* record dependency on the target variable of a LET command */
+ if (OidIsValid(query->resultVariable))
+ record_plan_variable_dependency(context, query->resultVariable);
+
/* And recurse into the query's subexpressions */
return query_tree_walker(query, extract_query_dependencies_walker,
context, 0);
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index d131a5bbc59..6fd04dadfcf 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -1573,6 +1573,9 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
/* If subquery had any RLS conditions, now main query does too */
parse->hasRowSecurity |= subquery->hasRowSecurity;
+ /* if the subquery had session variables, the main query does too */
+ parse->hasSessionVariables |= subquery->hasSessionVariables;
+
/*
* subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
* hasTargetSRFs, so no work needed on those flags
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 43dfecfb47f..f60828f862e 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -24,6 +24,7 @@
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "commands/session_variable.h"
#include "executor/executor.h"
#include "executor/functions.h"
#include "funcapi.h"
@@ -934,6 +935,13 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
if (param->paramkind == PARAM_EXTERN)
return false;
+ /* we don't support passing session variables to workers */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
+ return true;
+ }
+
if (param->paramkind != PARAM_EXEC ||
!list_member_int(context->safe_param_ids, param->paramid))
{
@@ -2389,6 +2397,7 @@ convert_saop_to_hashed_saop_walker(Node *node, void *context)
* value of the Param.
* 2. Fold stable, as well as immutable, functions to constants.
* 3. Reduce PlaceHolderVar nodes to their contained expressions.
+ * 4. Current value of session variable can be used for estimation too.
*--------------------
*/
Node *
@@ -2515,6 +2524,27 @@ eval_const_expressions_mutator(Node *node,
}
}
}
+ else if (param->paramkind == PARAM_VARIABLE &&
+ context->estimate)
+ {
+ int16 typLen;
+ bool typByVal;
+ Datum pval;
+ bool isnull;
+
+ get_typlenbyval(param->paramtype,
+ &typLen, &typByVal);
+
+ pval = GetSessionVariable(param->paramvarid, &isnull);
+
+ return (Node *) makeConst(param->paramtype,
+ param->paramtypmod,
+ param->paramcollid,
+ (int) typLen,
+ pval,
+ isnull,
+ typByVal);
+ }
/*
* Not replaceable, so just copy the Param (no need to
@@ -4720,7 +4750,8 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
querytree->limitOffset ||
querytree->limitCount ||
querytree->setOperations ||
- list_length(querytree->targetList) != 1)
+ (list_length(querytree->targetList) != 1) ||
+ querytree->hasSessionVariables)
goto fail;
/* If the function result is composite, resolve it */
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 76f58b3aca3..725f678e2fa 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -25,9 +25,12 @@
#include "postgres.h"
#include "access/sysattr.h"
+#include "catalog/namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
@@ -51,6 +54,7 @@
#include "utils/backend_status.h"
#include "utils/builtins.h"
#include "utils/guc.h"
+#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
@@ -83,6 +87,8 @@ static Query *transformCreateTableAsStmt(ParseState *pstate,
CreateTableAsStmt *stmt);
static Query *transformCallStmt(ParseState *pstate,
CallStmt *stmt);
+static Query *transformLetStmt(ParseState *pstate,
+ LetStmt *stmt);
static void transformLockingClause(ParseState *pstate, Query *qry,
LockingClause *lc, bool pushedDown);
#ifdef DEBUG_NODE_TESTS_ENABLED
@@ -414,6 +420,7 @@ transformStmt(ParseState *pstate, Node *parseTree)
case T_UpdateStmt:
case T_DeleteStmt:
case T_MergeStmt:
+ case T_LetStmt:
(void) test_raw_expression_coverage(parseTree, NULL);
break;
default:
@@ -493,6 +500,11 @@ transformStmt(ParseState *pstate, Node *parseTree)
(CallStmt *) parseTree);
break;
+ case T_LetStmt:
+ result = transformLetStmt(pstate,
+ (LetStmt *) parseTree);
+ break;
+
default:
/*
@@ -545,6 +557,7 @@ stmt_requires_parse_analysis(RawStmt *parseTree)
case T_SelectStmt:
case T_ReturnStmt:
case T_PLAssignStmt:
+ case T_LetStmt:
result = true;
break;
@@ -653,6 +666,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1078,6 +1092,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1543,6 +1558,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, stmt->lockingClause)
{
@@ -1769,12 +1785,241 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
return qry;
}
+/*
+ * transformLetStmt -
+ * transform an Let Statement
+ */
+static Query *
+transformLetStmt(ParseState *pstate, LetStmt *stmt)
+{
+ Query *query;
+ Query *result;
+ List *exprList = NIL;
+ List *exprListCoer = NIL;
+ ListCell *lc;
+ ListCell *indirection_head = NULL;
+ Query *selectQuery;
+ Oid varid;
+ char *attrname = NULL;
+ bool not_unique;
+ bool is_rowtype;
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+ List *names = NULL;
+ int indirection_start;
+ int i = 0;
+
+ /* there can't be any outer WITH to worry about */
+ Assert(pstate->p_ctenamespace == NIL);
+
+ names = NamesFromList(stmt->target);
+
+ /* locks the variable with an AccessShareLock */
+ varid = IdentifyVariable(names, &attrname, ¬_unique, false);
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("target \"%s\" of LET command is ambiguous",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ if (!OidIsValid(varid))
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ /*
+ * Calculate start of possible position of an indirection in list, and
+ * when it is inside the list, store pointer on first node of indirection.
+ */
+ indirection_start = list_length(names) - (attrname ? 1 : 0);
+ if (list_length(stmt->target) > indirection_start)
+ indirection_head = list_nth_cell(stmt->target, indirection_start);
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod, &collid);
+
+ is_rowtype = type_is_rowtype(typid);
+
+ if (attrname && !is_rowtype)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("cannot assign to field \"%s\" of session variable \"%s.%s\" because its type %s is not a composite type",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->location)));
+
+ pstate->p_expr_kind = EXPR_KIND_LET_TARGET;
+
+ /* we need to postpone conversion of "unknown" to text */
+ pstate->p_resolve_unknowns = false;
+
+ selectQuery = transformStmt(pstate, stmt->query);
+
+ /* the grammar should have produced a SELECT */
+ Assert(IsA(selectQuery, Query) && selectQuery->commandType == CMD_SELECT);
+
+ /*
+ * Generate an expression list for the LET that selects all the non-resjunk
+ * columns from the subquery.
+ */
+ exprList = NIL;
+ foreach_node(TargetEntry, tle, selectQuery->targetList)
+ {
+ if (tle->resjunk)
+ continue;
+
+ exprList = lappend(exprList, tle->expr);
+ }
+
+ /* don't allow multicolumn result */
+ if (list_length(exprList) != 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg_plural("assignment expression returned %d column",
+ "assignment expression returned %d columns",
+ list_length(exprList),
+ list_length(exprList)),
+ parser_errposition(pstate,
+ exprLocation((Node *) exprList))));
+
+ exprListCoer = NIL;
+
+ foreach(lc, exprList)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ Expr *coerced_expr;
+ Oid exprtypid;
+
+ /* now we can read the type of the expression */
+ exprtypid = exprType((Node *) expr);
+
+ if (indirection_head)
+ {
+ bool targetIsArray;
+ char *targetName;
+ Param *param;
+
+ targetName = get_session_variable_name(varid);
+ targetIsArray = OidIsValid(get_element_type(typid));
+
+ pstate->p_hasSessionVariables = true;
+
+ param = makeNode(Param);
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+
+ /*
+ * The parameter used as basenode has to have special
+ * mark, because requires special access when we do
+ * SELECT access check.
+ */
+ param->parambasenode = true;
+
+ coerced_expr = (Expr *)
+ transformAssignmentIndirection(pstate,
+ (Node *) param,
+ targetName,
+ targetIsArray,
+ typid,
+ typmod,
+ InvalidOid,
+ stmt->target,
+ indirection_head,
+ (Node *) expr,
+ COERCION_ASSIGNMENT,
+ stmt->location);
+ }
+ else
+ coerced_expr = (Expr *)
+ coerce_to_target_type(pstate,
+ (Node *) expr,
+ exprtypid,
+ typid, typmod,
+ COERCION_ASSIGNMENT,
+ COERCE_IMPLICIT_CAST,
+ stmt->location);
+
+ if (coerced_expr == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("variable \"%s.%s\" is of type %s, but expression is of type %s",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid),
+ format_type_be(exprtypid)),
+ errhint("You will need to rewrite or cast the expression."),
+ parser_errposition(pstate, exprLocation((Node *) expr))));
+
+ exprListCoer = lappend(exprListCoer, coerced_expr);
+ }
+
+ /* generate query's target list using the computed list of expressions */
+ query = makeNode(Query);
+ query->commandType = CMD_SELECT;
+
+ foreach(lc, exprListCoer)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ TargetEntry *tle;
+
+ tle = makeTargetEntry(expr,
+ i + 1,
+ FigureColname((Node *) expr),
+ false);
+ query->targetList = lappend(query->targetList, tle);
+ }
+
+ /* done building the range table and jointree */
+ query->rtable = pstate->p_rtable;
+ query->jointree = makeFromExpr(pstate->p_joinlist, NULL);
+
+ query->hasTargetSRFs = pstate->p_hasTargetSRFs;
+ query->hasSubLinks = pstate->p_hasSubLinks;
+ query->hasSessionVariables = pstate->p_hasSessionVariables;
+
+ /* this is top-level query */
+ query->canSetTag = true;
+
+ /*
+ * Save target session variable ID. It is used later for
+ * acquiring an AccessShareLock on target variable, setting
+ * plan dependency and finally for creating VariableDestReceiver.
+ */
+ query->resultVariable = varid;
+
+ assign_query_collations(pstate, query);
+
+ /*
+ * The query is executed as utility command by nested executor call.
+ * Assigned queryId is required in this case.
+ */
+ if (IsQueryIdEnabled())
+ JumbleQuery(query);
+
+ stmt->query = (Node *) query;
+
+ /* represent the command as a utility Query */
+ result = makeNode(Query);
+ result->commandType = CMD_UTILITY;
+ result->utilityStmt = (Node *) stmt;
+
+ return result;
+}
+
/*
* transformSetOperationStmt -
* transforms a set-operations tree
@@ -2020,6 +2265,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, lockingClause)
{
@@ -2495,6 +2741,7 @@ transformReturnStmt(ParseState *pstate, ReturnStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2562,6 +2809,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2852,9 +3100,15 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
/*
* Transform the target reference. Typically we will get back a Param
* node, but there's no reason to be too picky about its type.
+ *
+ * Session variables should not be used as target of a PL/pgSQL assign
+ * statement. So we should use a dedicated expression kind and disallow
+ * session variables there. The dedicated context allows to eliminate
+ * undesirable warnings about the possibility of a target PL/pgSQL variable
+ * shadowing a session variable.
*/
target = transformExpr(pstate, (Node *) cref,
- EXPR_KIND_UPDATE_TARGET);
+ EXPR_KIND_ASSIGN_TARGET);
targettype = exprType(target);
targettypmod = exprTypmod(target);
targetcollation = exprCollation(target);
@@ -2896,6 +3150,10 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
*/
type_id = exprType((Node *) tle->expr);
+ /*
+ * For indirection processing and additional casts we can use expr_kind
+ * EXPR_KIND_UPDATE_TARGET.
+ */
pstate->p_expr_kind = EXPR_KIND_UPDATE_TARGET;
if (indirection)
@@ -3038,6 +3296,8 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
(LockingClause *) lfirst(l), false);
}
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
+
assign_query_collations(pstate, qry);
/* this must be done after collations, for reliable comparison of exprs */
@@ -3311,6 +3571,16 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt)
true,
stmt->funccall->location);
+ /*
+ * The arguments of CALL statement are evaluated by a direct expression
+ * executor call. This path is unsupported yet, so block it. It will be
+ * enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
assign_expr_collations(pstate, node);
fexpr = castNode(FuncExpr, node);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index d682c0f7b87..58347b296fc 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -297,7 +297,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
DropTransformStmt
DropUserMappingStmt ExplainStmt FetchStmt
GrantStmt GrantRoleStmt ImportForeignSchemaStmt IndexStmt InsertStmt
- ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
+ LetStmt ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
CreateFunctionStmt AlterFunctionStmt ReindexStmt RemoveAggrStmt
RemoveFuncStmt RemoveOperStmt RenameStmt ReturnStmt RevokeStmt RevokeRoleStmt
RuleActionStmt RuleActionStmtOrEmpty RuleStmt
@@ -742,7 +742,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
KEEP KEY KEYS
LABEL LANGUAGE LARGE_P LAST_P LATERAL_P
- LEADING LEAKPROOF LEAST LEFT LEVEL LIKE LIMIT LISTEN LOAD LOCAL
+ LEADING LEAKPROOF LEAST LEFT LET LEVEL LIKE LIMIT LISTEN LOAD LOCAL
LOCALTIME LOCALTIMESTAMP LOCATION LOCK_P LOCKED LOGGED
MAPPING MATCH MATCHED MATERIALIZED MAXVALUE MERGE MERGE_ACTION METHOD
@@ -1089,6 +1089,7 @@ stmt:
| ImportForeignSchemaStmt
| IndexStmt
| InsertStmt
+ | LetStmt
| ListenStmt
| RefreshMatViewStmt
| LoadStmt
@@ -12873,6 +12874,38 @@ opt_hold: /* EMPTY */ { $$ = 0; }
| WITHOUT HOLD { $$ = 0; }
;
+/*****************************************************************************
+ *
+ * QUERY:
+ * LET STATEMENT
+ *
+ *****************************************************************************/
+LetStmt: LET ColId opt_indirection '=' a_expr
+ {
+ LetStmt *n = makeNode(LetStmt);
+ SelectStmt *select;
+ ResTarget *res;
+
+ n->target = lcons(makeString($2),
+ check_indirection($3, yyscanner));
+
+ select = makeNode(SelectStmt);
+ res = makeNode(ResTarget);
+
+ /* create target list for implicit query */
+ res->name = NULL;
+ res->indirection = NIL;
+ res->val = (Node *) $5;
+ res->location = @5;
+
+ select->targetList = list_make1(res);
+ n->query = (Node *) select;
+
+ n->location = @2;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* QUERY:
@@ -17944,6 +17977,7 @@ unreserved_keyword:
| LARGE_P
| LAST_P
| LEAKPROOF
+ | LET
| LEVEL
| LISTEN
| LOAD
@@ -18557,6 +18591,7 @@ bare_label_keyword:
| LEAKPROOF
| LEAST
| LEFT
+ | LET
| LEVEL
| LIKE
| LISTEN
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 0ac8966e30f..de0a4a5653a 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -580,6 +580,11 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
+
/*
* There is intentionally no default: case here, so that the
* compiler will warn if we add a new ParseExprKind without
@@ -970,6 +975,10 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
case EXPR_KIND_CYCLE_MARK:
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 9caf1e481a2..55e4906ad76 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -17,6 +17,7 @@
#include "catalog/pg_aggregate.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
@@ -33,11 +34,13 @@
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "parser/parse_type.h"
+#include "storage/lmgr.h"
#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/timestamp.h"
+#include "utils/typcache.h"
#include "utils/xml.h"
/* GUC parameters */
@@ -106,6 +109,9 @@ static Expr *make_distinct_op(ParseState *pstate, List *opname,
Node *ltree, Node *rtree, int location);
static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
+static Node *makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location);
/*
@@ -499,6 +505,89 @@ transformIndirection(ParseState *pstate, A_Indirection *ind)
return result;
}
+/*
+ * Returns true if the given expression kind is valid for session variables.
+ * Session variables can be used everywhere where external parameters can be
+ * used. Session variables are not allowed in DDL commands or in constraints.
+ *
+ * An identifier can be parsed as a session variable only for expression kinds
+ * where session variables are allowed. This is the primary usage of this
+ * function.
+ *
+ * The second usage of this function is to decide whether a "column does not
+ * exist" or a "column or variable does not exist" error message should be
+ * printed. When we are in an expression where session variables cannot be
+ * used, we raise the first form of error message.
+ */
+static bool
+expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
+{
+ bool result = false;
+
+ switch (p_expr_kind)
+ {
+ case EXPR_KIND_NONE:
+ Assert(false); /* can't happen */
+ return false;
+
+ /* session variables allowed */
+ case EXPR_KIND_OTHER:
+ case EXPR_KIND_JOIN_ON:
+ case EXPR_KIND_FROM_SUBSELECT:
+ case EXPR_KIND_FROM_FUNCTION:
+ case EXPR_KIND_WHERE:
+ case EXPR_KIND_HAVING:
+ case EXPR_KIND_FILTER:
+ case EXPR_KIND_WINDOW_PARTITION:
+ case EXPR_KIND_WINDOW_ORDER:
+ case EXPR_KIND_WINDOW_FRAME_RANGE:
+ case EXPR_KIND_WINDOW_FRAME_ROWS:
+ case EXPR_KIND_WINDOW_FRAME_GROUPS:
+ case EXPR_KIND_SELECT_TARGET:
+ case EXPR_KIND_INSERT_TARGET:
+ case EXPR_KIND_UPDATE_SOURCE:
+ case EXPR_KIND_UPDATE_TARGET:
+ case EXPR_KIND_MERGE_WHEN:
+ case EXPR_KIND_MERGE_RETURNING:
+ case EXPR_KIND_GROUP_BY:
+ case EXPR_KIND_ORDER_BY:
+ case EXPR_KIND_DISTINCT_ON:
+ case EXPR_KIND_LIMIT:
+ case EXPR_KIND_OFFSET:
+ case EXPR_KIND_RETURNING:
+ case EXPR_KIND_VALUES:
+ case EXPR_KIND_VALUES_SINGLE:
+ case EXPR_KIND_ALTER_COL_TRANSFORM:
+ case EXPR_KIND_EXECUTE_PARAMETER:
+ case EXPR_KIND_POLICY:
+ case EXPR_KIND_CALL_ARGUMENT:
+ case EXPR_KIND_COPY_WHERE:
+ case EXPR_KIND_LET_TARGET:
+ result = true;
+ break;
+
+ /* session variables not allowed */
+ case EXPR_KIND_CHECK_CONSTRAINT:
+ case EXPR_KIND_DOMAIN_CHECK:
+ case EXPR_KIND_COLUMN_DEFAULT:
+ case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_INDEX_EXPRESSION:
+ case EXPR_KIND_INDEX_PREDICATE:
+ case EXPR_KIND_STATS_EXPRESSION:
+ case EXPR_KIND_TRIGGER_WHEN:
+ case EXPR_KIND_PARTITION_BOUND:
+ case EXPR_KIND_PARTITION_EXPRESSION:
+ case EXPR_KIND_GENERATED_COLUMN:
+ case EXPR_KIND_JOIN_USING:
+ case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ result = false;
+ break;
+ }
+
+ return result;
+}
+
/*
* Transform a ColumnRef.
*
@@ -575,6 +664,8 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
case EXPR_KIND_COPY_WHERE:
case EXPR_KIND_GENERATED_COLUMN:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
@@ -847,8 +938,61 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
}
/*
- * Throw error if no translation found.
+ * There are contexts where session variables are not allowed. We don't
+ * need to identify session variables in such a context, but identifying
+ * them allows us to raise meaningful error messages like "you cannot use
+ * session variables here".
*/
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind))
+ {
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* -----
+ * Session variables are shadowed by columns, routine variables or
+ * routine arguments. We certainly don't want to use a session variable
+ * when it is exactly shadowed, but a RTE like this is conceivable:
+ *
+ * CREATE TYPE t AS (c int);
+ * CREATE VARIABLE foo AS t;
+ * CREATE TABLE foo(a int, b int);
+ *
+ * SELECT foo.a, foo.b, foo.c FROM foo;
+ *
+ * However, that is very confusing, so we disallow it. We don't try to
+ * identify a variable if we know that it would be shadowed.
+ * -----
+ */
+ if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ {
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(cref->fields)),
+ parser_errposition(pstate, cref->location)));
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ node = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, cref->location);
+ }
+ }
+ }
+
+ /* throw an error if no translation was found */
if (node == NULL)
{
switch (crerr)
@@ -880,6 +1024,75 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
return node;
}
+/*
+ * Generate param variable for reference to session variable
+ */
+static Node *
+makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location)
+{
+ Param *param;
+
+ param = makeNode(Param);
+
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+ param->paramcollid = collid;
+
+ pstate->p_hasSessionVariables = true;
+
+ if (attrname != NULL)
+ {
+ TupleDesc tupdesc;
+ int i;
+
+ tupdesc = lookup_rowtype_tupdesc_noerror(typid, typmod, true);
+ if (!tupdesc)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("variable \"%s.%s\" is of type \"%s\", which is not a composite type",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, location)));
+
+ for (i = 0; i < tupdesc->natts; i++)
+ {
+ Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+ if (strcmp(attrname, NameStr(att->attname)) == 0 &&
+ !att->attisdropped)
+ {
+ /* success, so generate a FieldSelect expression */
+ FieldSelect *fselect = makeNode(FieldSelect);
+
+ fselect->arg = (Expr *) param;
+ fselect->fieldnum = i + 1;
+ fselect->resulttype = att->atttypid;
+ fselect->resulttypmod = att->atttypmod;
+ /* save attribute's collation for parse_collate.c */
+ fselect->resultcollid = att->attcollation;
+
+ ReleaseTupleDesc(tupdesc);
+ return (Node *) fselect;
+ }
+ }
+
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_COLUMN),
+ errmsg("could not identify column \"%s\" in variable \"%s.%s\"",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ parser_errposition(pstate, location)));
+ }
+
+ return (Node *) param;
+}
+
static Node *
transformParamRef(ParseState *pstate, ParamRef *pref)
{
@@ -1815,6 +2028,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_VALUES:
case EXPR_KIND_VALUES_SINGLE:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
case EXPR_KIND_CHECK_CONSTRAINT:
@@ -1858,6 +2072,9 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_GENERATED_COLUMN:
err = _("cannot use subquery in column generation expression");
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ err = _("cannot use subquery as target of assign statement");
+ break;
/*
* There is intentionally no default: case here, so that the
@@ -3215,6 +3432,10 @@ ParseExprKindName(ParseExprKind exprKind)
return "GENERATED AS";
case EXPR_KIND_CYCLE_MARK:
return "CYCLE";
+ case EXPR_KIND_ASSIGN_TARGET:
+ return "ASSIGN";
+ case EXPR_KIND_LET_TARGET:
+ return "LET";
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index 583bbbf232f..dc25f6dcd0e 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2656,6 +2656,8 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location)
err = _("set-returning functions are not allowed in column generation expressions");
break;
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
errkind = true;
break;
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
index 51d7703eff7..244efcddf32 100644
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -405,6 +405,7 @@ transformMergeStmt(ParseState *pstate, MergeStmt *stmt)
qry->hasTargetSRFs = false;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c
index b620766c938..b2f764b657f 100644
--- a/src/backend/tcop/dest.c
+++ b/src/backend/tcop/dest.c
@@ -38,6 +38,7 @@
#include "executor/functions.h"
#include "executor/tqueue.h"
#include "executor/tstoreReceiver.h"
+#include "executor/svariableReceiver.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
@@ -155,6 +156,9 @@ CreateDestReceiver(CommandDest dest)
case DestExplainSerialize:
return CreateExplainSerializeDestReceiver(NULL);
+
+ case DestVariable:
+ return CreateVariableDestReceiver(InvalidOid);
}
/* should never get here */
@@ -191,6 +195,7 @@ EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_o
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -237,6 +242,7 @@ NullCommand(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -281,6 +287,7 @@ ReadyForQuery(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 99a51877d34..7a508a3644f 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -49,6 +49,7 @@
#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
+#include "commands/session_variable.h"
#include "commands/subscriptioncmds.h"
#include "commands/tablecmds.h"
#include "commands/tablespace.h"
@@ -235,6 +236,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CallStmt:
case T_DoStmt:
+ case T_LetStmt:
{
/*
* Commands inside the DO block or the called procedure might
@@ -1067,6 +1069,11 @@ standard_ProcessUtility(PlannedStmt *pstmt,
break;
}
+ case T_LetStmt:
+ ExecuteLetStmt(pstate, (LetStmt *) parsetree, params,
+ queryEnv, qc);
+ break;
+
default:
/* All other statement types have event trigger support */
ProcessUtilitySlow(pstate, pstmt, queryString,
@@ -2206,6 +2213,10 @@ UtilityContainsQuery(Node *parsetree)
return UtilityContainsQuery(qry->utilityStmt);
return qry;
+ case T_LetStmt:
+ qry = castNode(Query, ((LetStmt *) parsetree)->query);
+ return qry;
+
default:
return NULL;
}
@@ -2404,6 +2415,10 @@ CreateCommandTag(Node *parsetree)
tag = CMDTAG_SELECT;
break;
+ case T_LetStmt:
+ tag = CMDTAG_LET;
+ break;
+
/* utility statements --- same whether raw or cooked */
case T_TransactionStmt:
{
@@ -3289,6 +3304,7 @@ GetCommandLogLevel(Node *parsetree)
break;
case T_PLAssignStmt:
+ case T_LetStmt:
lev = LOGSTMT_ALL;
break;
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 9e90acedb91..d6bdae9af7d 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -37,6 +37,7 @@
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablespace.h"
#include "common/keywords.h"
@@ -534,6 +535,7 @@ static char *generate_function_name(Oid funcid, int nargs,
static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2);
static void add_cast_to(StringInfo buf, Oid typid);
static char *generate_qualified_type_name(Oid typid);
+static char *generate_session_variable_name(Oid varid);
static text *string_to_text(char *str);
static char *flatten_reloptions(Oid relid);
static void get_reloptions(StringInfo buf, Datum reloptions);
@@ -8729,6 +8731,14 @@ get_parameter(Param *param, deparse_context *context)
return;
}
+ /* translate paramvarid to session variable name */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ return;
+ }
+
/*
* Alternatively, maybe it's a subplan output, which we print as a
* reference to the subplan. (We could drill down into the subplan and
@@ -13556,6 +13566,42 @@ generate_collation_name(Oid collid)
return result;
}
+/*
+ * generate_session_variable_name
+ * Compute the name to display for a session variable specified by OID
+ *
+ * The result includes all necessary quoting and schema-prefixing.
+ */
+static char *
+generate_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+ char *nspname;
+ char *result;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = NameStr(varform->varname);
+
+ if (!VariableIsVisible(varid))
+ nspname = get_namespace_name_or_temp(varform->varnamespace);
+ else
+ nspname = NULL;
+
+ result = quote_qualified_identifier(nspname, varname);
+
+ ReleaseSysCache(tup);
+
+ return result;
+}
+
/*
* Given a C string, produce a TEXT datum.
*
diff --git a/src/backend/utils/cache/plancache.c b/src/backend/utils/cache/plancache.c
index 6c2979d5c82..88574766861 100644
--- a/src/backend/utils/cache/plancache.c
+++ b/src/backend/utils/cache/plancache.c
@@ -58,6 +58,7 @@
#include "access/transam.h"
#include "catalog/namespace.h"
+#include "catalog/pg_variable.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
@@ -163,6 +164,7 @@ InitPlanCache(void)
CacheRegisterSyscacheCallback(AMOPOPID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNSERVEROID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNDATAWRAPPEROID, PlanCacheSysCallback, (Datum) 0);
+ CacheRegisterSyscacheCallback(VARIABLEOID, PlanCacheObjectCallback, (Datum) 0);
}
/*
@@ -2050,17 +2052,32 @@ ScanQueryForLocks(Query *parsetree, bool acquire)
/*
* Recurse into sublink subqueries, too. But we already did the ones in
- * the rtable and cteList.
+ * the rtable and cteList. We need to force a recursive call for session
+ * variables too, to find and lock variables used in the query (see
+ * ScanQueryWalker).
*/
- if (parsetree->hasSubLinks)
+ if (parsetree->hasSubLinks ||
+ parsetree->hasSessionVariables)
{
query_tree_walker(parsetree, ScanQueryWalker, &acquire,
QTW_IGNORE_RC_SUBQUERIES);
}
+
+ /* process session variables */
+ if (OidIsValid(parsetree->resultVariable))
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ }
}
/*
- * Walker to find sublink subqueries for ScanQueryForLocks
+ * Walker to find sublink subqueries or referenced session variables
+ * for ScanQueryForLocks
*/
static bool
ScanQueryWalker(Node *node, bool *acquire)
@@ -2075,6 +2092,20 @@ ScanQueryWalker(Node *node, bool *acquire)
ScanQueryForLocks(castNode(Query, sub->subselect), *acquire);
/* Fall through to process lefthand args of SubLink */
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ }
+ }
/*
* Do NOT recurse into Query nodes, because ScanQueryForLocks already
@@ -2205,7 +2236,9 @@ PlanCacheRelCallback(Datum arg, Oid relid)
/*
* PlanCacheObjectCallback
- * Syscache inval callback function for PROCOID and TYPEOID caches
+ * Syscache inval callback function for TYPEOID, PROCOID, NAMESPACEOID,
+ * OPEROID, AMOPOPID, FOREIGNSERVEROID, FOREIGNDATAWRAPPEROID and
+ * VARIABLEOID caches.
*
* Invalidate all plans mentioning the object with the specified hash value,
* or all plans mentioning any member of this cache if hashvalue == 0.
diff --git a/src/backend/utils/fmgr/fmgr.c b/src/backend/utils/fmgr/fmgr.c
index 782291d9998..093622fbdc4 100644
--- a/src/backend/utils/fmgr/fmgr.c
+++ b/src/backend/utils/fmgr/fmgr.c
@@ -2026,9 +2026,13 @@ get_call_expr_arg_stable(Node *expr, int argnum)
*/
if (IsA(arg, Const))
return true;
- if (IsA(arg, Param) &&
- ((Param *) arg)->paramkind == PARAM_EXTERN)
- return true;
+ if (IsA(arg, Param))
+ {
+ Param *p = (Param *) arg;
+
+ if (p->paramkind == PARAM_EXTERN || p->paramkind == PARAM_VARIABLE)
+ return true;
+ }
return false;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 84907f76c0a..dfe821f4b60 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1228,8 +1228,8 @@ static const char *const sql_commands[] = {
"ABORT", "ALTER", "ANALYZE", "BEGIN", "CALL", "CHECKPOINT", "CLOSE", "CLUSTER",
"COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE",
"DELETE FROM", "DISCARD", "DO", "DROP", "END", "EXECUTE", "EXPLAIN",
- "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LISTEN", "LOAD", "LOCK",
- "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
+ "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LET",
+ "LISTEN", "LOAD", "LOCK", "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
"REASSIGN", "REFRESH MATERIALIZED VIEW", "REINDEX", "RELEASE",
"RESET", "REVOKE", "ROLLBACK",
"SAVEPOINT", "SECURITY LABEL", "SELECT", "SET", "SHOW", "START",
@@ -4689,6 +4689,14 @@ match_previous_words(int pattern_id,
else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES"))
COMPLETE_WITH("(");
+/* LET */
+ /* If prev. word is LET suggest a list of variables */
+ else if (Matches("LET"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ /* Complete LET <variable> with "=" */
+ else if (TailMatches("LET", MatchAny))
+ COMPLETE_WITH("=");
+
/* LOCK */
/* Complete LOCK [TABLE] [ONLY] with a list of tables */
else if (Matches("LOCK"))
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index bdac0c13bec..5060b8c9490 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -174,6 +174,7 @@ extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
extern List *NamesFromList(List *names);
extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+extern Oid IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror);
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 3d3c6eb24b5..5b45be5afaf 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -18,6 +18,7 @@
#ifndef PG_VARIABLE_H
#define PG_VARIABLE_H
+#include "access/xlogdefs.h"
#include "catalog/genbki.h"
#include "catalog/objectaddress.h"
#include "catalog/pg_variable_d.h"
@@ -35,6 +36,14 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* OID of entry in pg_type for variable's type */
Oid vartype BKI_LOOKUP(pg_type);
+ /*
+ * Used for identity check [oid, create_lsn].
+ *
+ * This column of the 8-byte XlogRecPtr type should be at an address that
+ * is divisible by 8, but before any column of type NameData.
+ */
+ XLogRecPtr varcreate_lsn;
+
/* variable name */
NameData varname;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
new file mode 100644
index 00000000000..2391b9ad443
--- /dev/null
+++ b/src/include/commands/session_variable.h
@@ -0,0 +1,30 @@
+/*-------------------------------------------------------------------------
+ *
+ * sessionvariable.h
+ * prototypes for sessionvariable.c.
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/commands/session_variable.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SESSIONVARIABLE_H
+#define SESSIONVARIABLE_H
+
+#include "nodes/params.h"
+#include "nodes/parsenodes.h"
+#include "parser/parse_node.h"
+#include "tcop/cmdtag.h"
+#include "utils/queryenvironment.h"
+
+extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
+extern Datum GetSessionVariable(Oid varid, bool *isNull);
+
+extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
+ QueryEnvironment *queryEnv, QueryCompletion *qc);
+
+#endif
diff --git a/src/include/executor/svariableReceiver.h b/src/include/executor/svariableReceiver.h
new file mode 100644
index 00000000000..db44d8b94c6
--- /dev/null
+++ b/src/include/executor/svariableReceiver.h
@@ -0,0 +1,22 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.h
+ * prototypes for svariableReceiver.c
+ *
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/executor/svariableReceiver.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SVARIABLE_RECEIVER_H
+#define SVARIABLE_RECEIVER_H
+
+#include "tcop/dest.h"
+
+extern DestReceiver *CreateVariableDestReceiver(Oid varid);
+
+#endif /* SVARIABLE_RECEIVER_H */
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index d4d4e655180..3ad2702a4b4 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -636,6 +636,16 @@ typedef struct AsyncRequest
* tuples) */
} AsyncRequest;
+/* ----------------
+ * SessionVariableValue
+ * ----------------
+ */
+typedef struct SessionVariableValue
+{
+ bool isnull;
+ Datum value;
+} SessionVariableValue;
+
/* ----------------
* EState information
*
@@ -696,6 +706,10 @@ typedef struct EState
ParamListInfo es_param_list_info; /* values of external params */
ParamExecData *es_param_exec_vals; /* values of internal params */
+ /* Session variables info: */
+ int es_num_session_variables; /* number of used variables */
+ SessionVariableValue *es_session_variables; /* array of copies of values */
+
QueryEnvironment *es_queryEnv; /* query environment */
/* Other working state: */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 09adbd490cc..a21d1d2e99f 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -142,6 +142,9 @@ typedef struct Query
*/
int resultRelation pg_node_attr(query_jumble_ignore);
+ /* target variable of LET statement */
+ Oid resultVariable;
+
/* has aggregates in tlist or havingQual */
bool hasAggs pg_node_attr(query_jumble_ignore);
/* has window functions in tlist */
@@ -162,6 +165,8 @@ typedef struct Query
bool hasRowSecurity pg_node_attr(query_jumble_ignore);
/* parser has added an RTE_GROUP RTE */
bool hasGroupRTE pg_node_attr(query_jumble_ignore);
+ /* uses session variables */
+ bool hasSessionVariables pg_node_attr(query_jumble_ignore);
/* is a RETURN statement */
bool isReturn pg_node_attr(query_jumble_ignore);
@@ -2144,6 +2149,18 @@ typedef struct MergeStmt
ParseLoc stmt_len; /* length in bytes; 0 means "rest of string" */
} MergeStmt;
+/* ----------------------
+ * Let Statement
+ * ----------------------
+ */
+typedef struct LetStmt
+{
+ NodeTag type;
+ List *target; /* target variable */
+ Node *query; /* source expression */
+ ParseLoc location;
+} LetStmt;
+
/* ----------------------
* Select Statement
*
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index fbf05322c75..b4988396a1c 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -179,6 +179,18 @@ typedef struct PlannerGlobal
/* partition descriptors */
PartitionDirectory partition_directory pg_node_attr(read_write_ignore);
+
+ /* list of used session variables */
+ List *sessionVariables;
+
+ /* Oid of session variable used like target of LET command */
+ Oid resultVariable;
+
+ /* oid of session variable used like base node for assignment indirection */
+ Oid basenodeSessionVarid;
+
+ /* true, if we do SELECT permission check on basenodeSessionVarid */
+ bool basenodeSessionVarSelectCheck;
} PlannerGlobal;
/* macro for fetching the Plan associated with a SubPlan node */
@@ -529,6 +541,8 @@ struct PlannerInfo
bool placeholdersFrozen;
/* true if planning a recursive WITH item */
bool hasRecursion;
+ /* true if session variables were used */
+ bool hasSessionVariables;
/*
* The rangetable index for the RTE_GROUP RTE, or 0 if there is no
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index 22841211f48..8675e1c7f64 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -128,6 +128,15 @@ typedef struct PlannedStmt
/* non-null if this is utility stmt */
Node *utilityStmt;
+ List *sessionVariables; /* OIDs for PARAM_VARIABLE Params */
+
+ /*
+ * The oid of session variable execluded from permission check.
+ * This session variable is used as base node of assignment indirection
+ * (and it is used only there).
+ */
+ int exclSelectPermCheckVarid;
+
/* statement location in source string (copied from Query) */
/* start location, or -1 if unknown */
ParseLoc stmt_location;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index d0576da3e25..24033045746 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -378,6 +378,9 @@ typedef struct Const
* of the `paramid' field contain the SubLink's subLinkId, and
* the low-order 16 bits contain the column number. (This type
* of Param is also converted to PARAM_EXEC during planning.)
+ *
+ * PARAM_VARIABLE: The parameter is a reference to a session variable
+ * (paramvarid holds the variable's OID).
*/
typedef enum ParamKind
{
@@ -385,6 +388,7 @@ typedef enum ParamKind
PARAM_EXEC,
PARAM_SUBLINK,
PARAM_MULTIEXPR,
+ PARAM_VARIABLE,
} ParamKind;
typedef struct Param
@@ -397,6 +401,16 @@ typedef struct Param
int32 paramtypmod pg_node_attr(query_jumble_ignore);
/* OID of collation, or InvalidOid if none */
Oid paramcollid pg_node_attr(query_jumble_ignore);
+ /* OID of session variable if it is used */
+ Oid paramvarid pg_node_attr(query_jumble_ignore);
+
+ /*
+ * true if param is used as base node of assignment indirection
+ * (when target of LET statement is an array field or an record field).
+ * For this param we do not check SELECT access right, because this
+ * param is used just for execution of UPDATE operation.
+ */
+ bool parambasenode;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index 5a930199611..7a3b522b5ff 100644
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -131,4 +131,6 @@ extern void record_plan_function_dependency(PlannerInfo *root, Oid funcid);
extern void record_plan_type_dependency(PlannerInfo *root, Oid typid);
extern bool extract_query_dependencies_walker(Node *node, PlannerInfo *context);
+extern void pull_up_has_session_variables(PlannerInfo *root);
+
#endif /* PLANMAIN_H */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 793ace526df..431167f6b43 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -257,6 +257,7 @@ PG_KEYWORD("leading", LEADING, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("leakproof", LEAKPROOF, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("least", LEAST, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("left", LEFT, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("let", LET, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("level", LEVEL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("like", LIKE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("limit", LIMIT, RESERVED_KEYWORD, AS_LABEL)
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 994284019fb..0b7b69a4159 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -82,6 +82,8 @@ typedef enum ParseExprKind
EXPR_KIND_COPY_WHERE, /* WHERE condition in COPY FROM */
EXPR_KIND_GENERATED_COLUMN, /* generation expression for a column */
EXPR_KIND_CYCLE_MARK, /* cycle mark value */
+ EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */
+ EXPR_KIND_LET_TARGET, /* LET target */
} ParseExprKind;
@@ -244,6 +246,7 @@ struct ParseState
bool p_hasTargetSRFs;
bool p_hasSubLinks;
bool p_hasModifyingCTE;
+ bool p_hasSessionVariables;
Node *p_last_srf; /* most recent set-returning func/op found */
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index ea86954dded..22082c30008 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -186,6 +186,7 @@ PG_CMDTAG(CMDTAG_GRANT, "GRANT", true, false, false)
PG_CMDTAG(CMDTAG_GRANT_ROLE, "GRANT ROLE", false, false, false)
PG_CMDTAG(CMDTAG_IMPORT_FOREIGN_SCHEMA, "IMPORT FOREIGN SCHEMA", true, false, false)
PG_CMDTAG(CMDTAG_INSERT, "INSERT", false, false, true)
+PG_CMDTAG(CMDTAG_LET, "LET", false, false, false)
PG_CMDTAG(CMDTAG_LISTEN, "LISTEN", false, false, false)
PG_CMDTAG(CMDTAG_LOAD, "LOAD", false, false, false)
PG_CMDTAG(CMDTAG_LOCK_TABLE, "LOCK TABLE", false, false, false)
diff --git a/src/include/tcop/dest.h b/src/include/tcop/dest.h
index 00c092e3d7c..6ce3ea0e617 100644
--- a/src/include/tcop/dest.h
+++ b/src/include/tcop/dest.h
@@ -97,6 +97,7 @@ typedef enum
DestTransientRel, /* results sent to transient relation */
DestTupleQueue, /* results sent to tuple queue */
DestExplainSerialize, /* results are serialized and discarded */
+ DestVariable, /* results sent to session variable */
} CommandDest;
/* ----------------
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index d4377ceecbf..cb282404c1a 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8264,7 +8264,8 @@ exec_is_simple_query(PLpgSQL_expr *expr)
query->sortClause ||
query->limitOffset ||
query->limitCount ||
- query->setOperations)
+ query->setOperations ||
+ query->hasSessionVariables)
return false;
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index c36660ce6d3..f22467186e3 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -431,3 +431,1235 @@ DROP VARIABLE public.var1;
DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+-- check access rights
+CREATE ROLE regress_noowner;
+CREATE VARIABLE var1 AS int;
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+-- should fail
+SET ROLE TO regress_noowner;
+SELECT var1;
+ERROR: permission denied for session variable var1
+SELECT sqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: SQL function "sqlfx" statement 1
+SELECT plpgsqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "$1 + var1"
+PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
+-- should be ok
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+-- should be ok
+SET ROLE TO regress_noowner;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+DROP ROLE regress_noowner;
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- start a new session
+\c
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- should fail, dependency
+DROP VARIABLE var1;
+ERROR: cannot drop session variable var1 because other objects depend on it
+DETAIL: view test_view depends on session variable var1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+NOTICE: drop cascades to view test_view
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+LET var1 = 'str1';
+LET var2 = 'str2';
+SELECT sqlfx1(sqlfx2('Hello'));
+ sqlfx1
+-------------------
+ str1, str2, Hello
+(1 row)
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+ QUERY PLAN
+------------------------------------------------------
+ Result
+ Output: sqlfx1(sqlfx2('Hello'::character varying))
+(2 rows)
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+SET plan_cache_mode TO force_generic_plan;
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 3.14
+(1 row)
+
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 6.28
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 9.42
+(1 row)
+
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 12.56
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+ERROR: function plpgsqlfx2() does not exist
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+SET plan_cache_mode TO DEFAULT;
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 1
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 55
+DROP VARIABLE var1;
+DROP TABLE testvar;
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+NOTICE: result array: {1,2,3,4,5,6,7,8,9,10}
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+-- should not crash (but is not supported yet)
+CALL p(v);
+ERROR: session variable cannot be used as an argument
+DO $$ BEGIN CALL p(v); END $$;
+ERROR: session variable cannot be used as an argument
+CONTEXT: SQL statement "CALL p(v)"
+PL/pgSQL function inline_code_block line 1 at CALL
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+-- should fail
+EXECUTE ptest(v);
+ERROR: session variable cannot be used as an argument
+DEALLOCATE ptest;
+DROP VARIABLE v;
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+-- should fail
+LET var1 = pi();
+ERROR: session variable "var1" doesn't exist
+LINE 1: LET var1 = pi();
+ ^
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+ var1
+------------------
+ 3.14159265358979
+(1 row)
+
+SET search_path TO svartest;
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+ var1
+------------------
+ 13.1415926535898
+(1 row)
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to session variable svartest.var1
+CREATE VARIABLE var1 AS text;
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+SELECT var1;
+ var1
+-------
+ hello
+(1 row)
+
+DROP VARIABLE var1;
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+-- should fail
+SELECT var1;
+ERROR: domain int_domain does not allow null values
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+ var1
+------
+ 1000
+(1 row)
+
+-- should fail
+LET var1 = 10;
+ERROR: value for domain int_domain violates check constraint "int_domain_check"
+-- should fail
+LET var1 = NULL;
+ERROR: domain int_domain does not allow null values
+-- note - domain defaults are not supported yet (like PLpgSQL)
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+ var1
+----------------------------------------
+ {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+(1 row)
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+DROP VARIABLE var1;
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+ var1
+------
+ 100
+(1 row)
+
+SET search_path to public, svartest;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table foo
+drop cascades to session variable var1
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+LET var2[var1] = 0;
+SELECT var2;
+ var2
+-----------
+ [2:2]={0}
+(1 row)
+
+DROP VARIABLE var1, var2;
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+SELECT var2;
+ var2
+------
+ {}
+(1 row)
+
+DROP VARIABLE var1, var2;
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+ERROR: syntax error at or near "LET"
+LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x;
+ ^
+-- should be ok
+LET var1 = generate_series(1, 1);
+-- should fail
+LET var1 = generate_series(1, 2);
+ERROR: expression returned more than one row
+LET var1 = generate_series(1, 0);
+ERROR: expression returned no rows
+DROP VARIABLE var1;
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+SELECT v1;
+ v1
+------------
+ (1,2,3.00)
+(1 row)
+
+SELECT v2;
+ v2
+---------------
+ (10,20,31.40)
+(1 row)
+
+SELECT (v1).*;
+ x | y | z
+---+---+------
+ 1 | 2 | 3.00
+(1 row)
+
+SELECT (v2).*;
+ x | y | z
+----+----+-------
+ 10 | 20 | 31.40
+(1 row)
+
+SELECT v1.x + v1.z;
+ ?column?
+----------
+ 4.00
+(1 row)
+
+SELECT v2.x + v2.z;
+ ?column?
+----------
+ 41.40
+(1 row)
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail
+SELECT v2.x;
+ERROR: permission denied for session variable v2
+SET ROLE TO DEFAULT;
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+ERROR: improper qualified name (too many dotted names): nodb.noschema.novar.nofield.nosubfield
+LET nodb.noschema.novar.nofield = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar.nofield
+LET nodb.noschema.novar = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar
+CREATE TYPE t1 AS (a int, b numeric, c text);
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+ v1
+----------------------------
+ (1,3.14159265358979,hello)
+(1 row)
+
+LET v1.b = 10.2222;
+SELECT v1;
+ v1
+-------------------
+ (1,10.2222,hello)
+(1 row)
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1
+LINE 1: LET v1.x = 10;
+ ^
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+ERROR: assignment expression returned 3 columns
+LINE 1: LET v1 = (NULL::t1).*;
+ ^
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+ v1
+-------------
+ (1,10.2222)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+ v1
+--------------
+ (1,10.2222,)
+(1 row)
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+ v1
+--------------
+ (10,10.3,20)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+ v1
+---------
+ (10,20)
+(1 row)
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+ERROR: cannot alter type "t1" because session variable "public.v1" uses it
+DROP VARIABLE v1;
+DROP TYPE t1;
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+ var1
+----------------------------------
+ (10,3.14159265358979,05-26-2023)
+(1 row)
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+ERROR: cannot alter table "svar_test" because session variable "public.var1" uses it
+-- should fail
+DROP TABLE svar_test;
+ERROR: cannot drop table svar_test because other objects depend on it
+DETAIL: session variable var1 depends on type svar_test
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+CREATE ROLE regress_var_test_role;
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+-- should fail
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+SELECT var1.a;
+ a
+------
+ 1000
+(1 row)
+
+SELECT var1;
+ var1
+------------
+ (1000,100)
+(1 row)
+
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+NOTICE: (0,100)
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+NOTICE: 0
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail again
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+-- should fail
+SELECT var1.a;
+ERROR: variable "public.var1" is of type "text", which is not a composite type
+LINE 1: SELECT var1.a;
+ ^
+SELECT var2.c;
+ERROR: could not identify column "c" in variable "public.var2"
+LINE 1: SELECT var2.c;
+ ^
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+-- should fail
+LET var1 = '1'::jsonb;
+ERROR: variable "public.var1" is of type integer, but expression is of type jsonb
+LINE 1: LET var1 = '1'::jsonb;
+ ^
+HINT: You will need to rewrite or cast the expression.
+-- should be ok
+LET var1 = '1'::jsonb::int;
+-- should fail
+LET var1.x = 10;
+ERROR: cannot assign to field "x" of session variable "public.var1" because its type integer is not a composite type
+LINE 1: LET var1.x = 10;
+ ^
+DROP VARIABLE var1;
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+-- should fail
+LET vartest.vartest = 1;
+ERROR: target "vartest.vartest" of LET command is ambiguous
+LINE 1: LET vartest.vartest = 1;
+ ^
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+ERROR: type "vartesttype" does not exist
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+ var1
+------------
+ {10.1,2.1}
+(1 row)
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+ERROR: set-returning functions are not allowed in LET
+LINE 1: LET var1[generate_series(1,3)] = 100;
+ ^
+DROP VARIABLE var1;
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+ var1
+--------------------
+ (10.2,"{0.0,0.0}")
+(1 row)
+
+LET var1.b[1] = 10.3;
+SELECT var1;
+ var1
+---------------------
+ (10.2,"{10.3,0.0}")
+(1 row)
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ count
+-------
+ 100
+(1 row)
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ QUERY PLAN
+-----------------------------------
+ Aggregate
+ -> Seq Scan on svar_test
+ Filter: ((a % 10) = zero)
+(3 rows)
+
+LET zero = (SELECT count(*) FROM svar_test);
+-- result should be 1000
+SELECT zero;
+ zero
+------
+ 1000
+(1 row)
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO on;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO off;
+DROP VIEW var1view;
+DROP VARIABLE var1;
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 100
+(1 row)
+
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 200
+(1 row)
+
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+---
+(0 rows)
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+ relname
+----------
+ pg_class
+(1 row)
+
+DROP VARIABLE var1;
+CREATE TABLE xxtab(avar int);
+INSERT INTO xxtab VALUES(333);
+CREATE TYPE xxtype AS (avar int);
+CREATE VARIABLE xxtab AS xxtype;
+INSERT INTO xxtab VALUES(10);
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+CREATE VARIABLE public.avar AS int;
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+ avar
+------
+
+
+(2 rows)
+
+DROP VARIABLE xxtab;
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+DROP VARIABLE public.avar;
+DROP TYPE xxtype;
+DROP TABLE xxtab;
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+CREATE TABLE public.svar(a int, b int);
+INSERT INTO public.svar VALUES(10, 20);
+LET public.svar = (100, 200, 300);
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT var1.* FROM vartest_foo;
+ ^
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+ a | b
+----+----
+ 10 | 20
+ 30 | 40
+(2 rows)
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT count(var1.*) FROM vartest_foo;
+ ^
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+ count
+-------
+ 2
+(1 row)
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table vartest.vartest_foo
+drop cascades to session variable vartest.var1
+CREATE TYPE ab AS (a integer, b integer);
+CREATE VARIABLE v_ab AS ab;
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+CREATE SCHEMA v_ab;
+CREATE VARIABLE v_ab.a AS integer;
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+SET search_path TO public;
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+-- should be ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+-- should be still ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+ERROR: session variable reference "xxx_am.b" is ambiguous
+LINE 1: SELECT xxx_am.b;
+ ^
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+ b
+----
+ 10
+(1 row)
+
+SELECT :"DBNAME".xxx_am.b;
+ b
+----
+ 20
+(1 row)
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+ b
+----
+ 10
+(1 row)
+
+SELECT x.b FROM xxx_am x;
+ b
+----
+ 10
+(1 row)
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+CREATE SCHEMA :"DBNAME";
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+SET search_path TO :"DBNAME";
+-- should be ambiguous
+SELECT :"DBNAME".b;
+ERROR: session variable reference "regression.b" is ambiguous
+LINE 1: SELECT "regression".b;
+ ^
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+ERROR: session variable reference "regression.regression.b" is ambiguous
+LINE 1: SELECT "regression"."regression".b;
+ ^
+CREATE TABLE :"DBNAME"(b int);
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+ b
+---
+(0 rows)
+
+DROP TABLE :"DBNAME";
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+RESET search_path;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index eeb0f94ca3c..e72360d5254 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -295,3 +295,886 @@ DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+
+-- check access rights
+CREATE ROLE regress_noowner;
+
+CREATE VARIABLE var1 AS int;
+
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+SELECT sqlfx(20);
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx(20);
+SELECT plpgsqlfx_sd(20);
+
+-- should fail
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+-- should be ok
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx_sd(20);
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+
+-- should be ok
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+
+DROP ROLE regress_noowner;
+
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- start a new session
+\c
+
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- should fail, dependency
+DROP VARIABLE var1;
+
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+
+LET var1 = 'str1';
+LET var2 = 'str2';
+
+SELECT sqlfx1(sqlfx2('Hello'));
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+
+SET plan_cache_mode TO force_generic_plan;
+
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+
+SET plan_cache_mode TO DEFAULT;
+
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP TABLE testvar;
+
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+
+-- should not crash (but is not supported yet)
+CALL p(v);
+
+DO $$ BEGIN CALL p(v); END $$;
+
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+
+-- should fail
+EXECUTE ptest(v);
+
+DEALLOCATE ptest;
+DROP VARIABLE v;
+
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+
+-- should fail
+LET var1 = pi();
+SELECT var1;
+
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+
+SET search_path TO svartest;
+
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS text;
+
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+
+-- should fail
+SELECT var1;
+
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+
+-- should fail
+LET var1 = 10;
+
+-- should fail
+LET var1 = NULL;
+
+-- note - domain defaults are not supported yet (like PLpgSQL)
+
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+
+SET search_path to public, svartest;
+
+SELECT var1;
+
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+LET var2[var1] = 0;
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+
+-- should be ok
+LET var1 = generate_series(1, 1);
+
+-- should fail
+LET var1 = generate_series(1, 2);
+LET var1 = generate_series(1, 0);
+
+DROP VARIABLE var1;
+
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+
+SELECT v1;
+SELECT v2;
+SELECT (v1).*;
+SELECT (v2).*;
+
+SELECT v1.x + v1.z;
+SELECT v2.x + v2.z;
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should fail
+SELECT v2.x;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+LET nodb.noschema.novar.nofield = 10;
+LET nodb.noschema.novar = 10;
+
+CREATE TYPE t1 AS (a int, b numeric, c text);
+
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+LET v1.b = 10.2222;
+SELECT v1;
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+
+DROP VARIABLE v1;
+DROP TYPE t1;
+
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+
+-- should fail
+DROP TABLE svar_test;
+
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+
+CREATE ROLE regress_var_test_role;
+
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+
+-- should fail
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should fail again
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+
+-- should fail
+SELECT var1.a;
+SELECT var2.c;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+
+CREATE VARIABLE var1 AS int;
+
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+
+-- should fail
+LET var1 = '1'::jsonb;
+
+-- should be ok
+LET var1 = '1'::jsonb::int;
+
+-- should fail
+LET var1.x = 10;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+
+-- should fail
+LET vartest.vartest = 1;
+
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+
+DROP VARIABLE var1;
+
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+LET var1.b[1] = 10.3;
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+LET zero = (SELECT count(*) FROM svar_test);
+
+-- result should be 1000
+SELECT zero;
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO on;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO off;
+
+DROP VIEW var1view;
+DROP VARIABLE var1;
+
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+
+DROP VARIABLE var1;
+
+CREATE TABLE xxtab(avar int);
+
+INSERT INTO xxtab VALUES(333);
+
+CREATE TYPE xxtype AS (avar int);
+
+CREATE VARIABLE xxtab AS xxtype;
+
+INSERT INTO xxtab VALUES(10);
+
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+
+-- should be ok
+SELECT avar FROM xxtab;
+
+CREATE VARIABLE public.avar AS int;
+
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+
+DROP VARIABLE xxtab;
+
+SELECT xxtab.avar FROM xxtab;
+
+DROP VARIABLE public.avar;
+
+DROP TYPE xxtype;
+
+DROP TABLE xxtab;
+
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+
+CREATE TABLE public.svar(a int, b int);
+
+INSERT INTO public.svar VALUES(10, 20);
+
+LET public.svar = (100, 200, 300);
+
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+
+CREATE TYPE ab AS (a integer, b integer);
+
+CREATE VARIABLE v_ab AS ab;
+
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+CREATE SCHEMA v_ab;
+
+CREATE VARIABLE v_ab.a AS integer;
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+
+SET search_path TO public;
+
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+
+-- should be ok
+SELECT xxx_am;
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+
+-- should be still ok
+SELECT xxx_am;
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+SELECT :"DBNAME".xxx_am.b;
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+SELECT x.b FROM xxx_am x;
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+
+CREATE SCHEMA :"DBNAME";
+
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+
+SET search_path TO :"DBNAME";
+
+-- should be ambiguous
+SELECT :"DBNAME".b;
+
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+
+CREATE TABLE :"DBNAME"(b int);
+
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+
+DROP TABLE :"DBNAME";
+
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+
+RESET search_path;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index d579941278a..424fb927e81 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1517,6 +1517,7 @@ LargeObjectDesc
Latch
LauncherLastStartTimesEntry
LerpFunc
+LetStmt
LexDescr
LexemeEntry
LexemeHashKey
@@ -2644,6 +2645,7 @@ SerializedTransactionState
Session
SessionBackupState
SessionEndType
+SessionVariableValue
SetConstraintState
SetConstraintStateData
SetConstraintTriggerData
@@ -2840,6 +2842,9 @@ SupportRequestRows
SupportRequestSelectivity
SupportRequestSimplify
SupportRequestWFuncMonotonic
+SVariable
+SVariableData
+SVariableState
Syn
SyncOps
SyncRepConfigData
--
2.48.1
[text/x-patch] v20250317-0005-memory-cleaning-after-DROP-VARIABLE.patch (20.9K, ../../CAFj8pRC_2tHski1K4hUMZm0+T4y7na4d8hwgMMF7Y0MXhfUhbg@mail.gmail.com/5-v20250317-0005-memory-cleaning-after-DROP-VARIABLE.patch)
download | inline diff:
From 3af2b5d3483521a294f4efe52bb430b432dc96b6 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 09:31:28 +0100
Subject: [PATCH 05/21] memory cleaning after DROP VARIABLE
Accepting a sinval message invalidates entries in the "sessionvars" hash table.
These entries are validated before any read or write operations on session variables.
When the entry cannot be validated, it is removed. Removal will be delayed when
the variable was dropped by the current transaction, which could still be rolled back.
---
src/backend/catalog/pg_variable.c | 7 +-
src/backend/commands/session_variable.c | 153 +++++++++++-
src/include/commands/session_variable.h | 2 +
.../isolation/expected/session-variable.out | 110 +++++++++
src/test/isolation/isolation_schedule | 1 +
.../isolation/specs/session-variable.spec | 50 ++++
.../regress/expected/session_variables.out | 217 ++++++++++++++++++
src/test/regress/sql/session_variables.sql | 120 ++++++++++
8 files changed, 655 insertions(+), 5 deletions(-)
create mode 100644 src/test/isolation/expected/session-variable.out
create mode 100644 src/test/isolation/specs/session-variable.spec
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index bb445e9434b..d672d2a9cb3 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -22,6 +22,7 @@
#include "catalog/pg_collation.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
@@ -230,7 +231,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
}
/*
- * Drop variable by OID
+ * Drop variable by OID, and register the needed session variable
+ * cleanup.
*/
void
DropVariableById(Oid varid)
@@ -250,4 +252,7 @@ DropVariableById(Oid varid)
ReleaseSysCache(tup);
table_close(rel, RowExclusiveLock);
+
+ /* do the necessary cleanup in local memory, if needed */
+ SessionVariableDropPostprocess(varid);
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index e1c86966998..1596d94fb03 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -14,6 +14,7 @@
*/
#include "postgres.h"
+#include "access/xact.h"
#include "catalog/pg_variable.h"
#include "commands/session_variable.h"
#include "executor/svariableReceiver.h"
@@ -67,6 +68,14 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ /*
+ * Top level local transaction id of the last transaction that dropped the
+ * variable, if any. We need this information to avoid freeing memory for
+ * variables dropped by the local backend, in case the operation is rolled
+ * back.
+ */
+ LocalTransactionId drop_lxid;
+
/*
* Stored value and type description can be outdated when we receive a
* sinval message. We then have to check if the stored data are still
@@ -83,6 +92,17 @@ static HTAB *sessionvars = NULL; /* hash table for session variables */
static MemoryContext SVariableMemoryContext = NULL;
+/* becomes true when we receive a sinval message */
+static bool needs_validation = false;
+
+/*
+ * The content of dropped session variables is not removed immediately. We do
+ * that in the next transaction that reads or writes a session variable.
+ * "validated_lxid" stores the transaction that performed said validation, so
+ * that we can avoid repeating the effort.
+ */
+static LocalTransactionId validated_lxid = InvalidLocalTransactionId;
+
/*
* Callback function for session variable invalidation.
*/
@@ -114,6 +134,38 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
if (hashvalue == 0 || svar->hashvalue == hashvalue)
{
svar->is_valid = false;
+ needs_validation = true;
+ }
+ }
+}
+
+/*
+ * Handle the local memory cleanup for a DROP VARIABLE command.
+ *
+ * Caller should take care of removing the pg_variable entry first.
+ */
+void
+SessionVariableDropPostprocess(Oid varid)
+{
+ Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid));
+
+ if (sessionvars)
+ {
+ bool found;
+ SVariable svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_FIND, &found);
+
+ if (found)
+ {
+ /*
+ * Save the current top level local transaction id to make sure we
+ * won't automatically remove the local variable storage in
+ * validate_all_session_variables() when the invalidation message
+ * from DROP VARIABLE arrives. After all, the transaction could
+ * still be rolled back.
+ */
+ svar->is_valid = false;
+ svar->drop_lxid = MyProc->vxid.lxid;
}
}
}
@@ -167,6 +219,67 @@ is_session_variable_valid(SVariable svar)
return result;
}
+/*
+ * Check all potentially invalid session variable data in local memory and free
+ * the memory for all invalid ones. This function is called before any read or
+ * write of a session variable. Freeing of a variable's memory is postponed if
+ * the variable has been dropped by the current transaction, since that
+ * operation could still be rolled back.
+ *
+ * It is possible that we receive a cache invalidation message while
+ * remove_invalid_session_variables() is executing, so we cannot guarantee that
+ * all entries in "sessionvars" will be set to "is_valid" after the function is
+ * done. However, we can guarantee that all entries get checked once.
+ */
+static void
+remove_invalid_session_variables(void)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ /*
+ * The validation requires system catalog access, so the session state
+ * should be "in transaction".
+ */
+ Assert(IsTransactionState());
+
+ if (!needs_validation || !sessionvars)
+ return;
+
+ /*
+ * Reset the flag before we start the validation. It can be set again
+ * by concurrently incoming sinval messages.
+ */
+ needs_validation = false;
+
+ elog(DEBUG1, "effective call of validate_all_session_variables()");
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (!svar->is_valid)
+ {
+ if (svar->drop_lxid == MyProc->vxid.lxid)
+ {
+ /* try again in the next transaction */
+ needs_validation = true;
+ continue;
+ }
+
+ if (!is_session_variable_valid(svar))
+ {
+ Oid varid = svar->varid;
+
+ free_session_variable_value(svar);
+ hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ else
+ svar->is_valid = true;
+ }
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
@@ -196,6 +309,8 @@ setup_session_variable(SVariable svar, Oid varid)
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+ svar->drop_lxid = InvalidTransactionId;
+
svar->isnull = true;
svar->value = (Datum) 0;
@@ -319,22 +434,42 @@ get_session_variable(Oid varid)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
if (found)
{
+ /*
+ * The session variable could have been dropped by a DROP VARIABLE
+ * statement in a subtransaction that was later rolled back, which
+ * means that we may have to work with the data of a variable marked
+ * as invalid.
+ */
if (!svar->is_valid)
{
/*
- * If there was an invalidation message, the variable might still be
- * valid, but we have to check with the system catalog.
+ * We have to check the system catalog to see if the variable is
+ * still valid, even if an invalidation message set it to invalid.
+ *
+ * The variable must be validated before it is accessed. The oid
+ * should be valid, because the related session variable is already
+ * locked, and remove_invalid_session_variables() would remove
+ * variables dropped by other transactions.
*/
if (is_session_variable_valid(svar))
svar->is_valid = true;
else
- /* if the value cannot be validated, we have to discard it */
- free_session_variable_value(svar);
+ elog(ERROR, "unexpected state of session variable %u", varid);
}
}
else
@@ -395,6 +530,16 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index a8ca43c87af..d3cc79b5608 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -21,6 +21,8 @@
#include "tcop/cmdtag.h"
#include "utils/queryenvironment.h"
+extern void SessionVariableDropPostprocess(Oid varid);
+
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
new file mode 100644
index 00000000000..0a5579dc7ce
--- /dev/null
+++ b/src/test/isolation/expected/session-variable.out
@@ -0,0 +1,110 @@
+Parsed test spec with 4 sessions
+
+starting permutation: let val drop val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+
+starting permutation: let val s1 drop val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+step sr1: ROLLBACK;
+
+starting permutation: let val dbg drop create dbg val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name|removed
+------+----+-------
+ | |t
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+
+starting permutation: let val s1 dbg drop create dbg val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+step sr1: ROLLBACK;
+
+starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+step create3: CREATE VARIABLE myvar3 AS text;
+step let3: LET myvar3 = 'test';
+step s3: BEGIN;
+step create4: CREATE VARIABLE myvar4 AS text;
+step let4: LET myvar4 = 'test';
+step drop4: DROP VARIABLE myvar4;
+step drop3: DROP VARIABLE myvar3;
+step inval3: SELECT COUNT(*) >= 0 FROM pg_foreign_table;
+?column?
+--------
+t
+(1 row)
+
+step discard: DISCARD VARIABLES;
+step sc3: COMMIT;
+step state: SELECT varname FROM pg_variable;
+varname
+-------
+myvar
+(1 row)
+
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 143109aa4da..7453685d046 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -115,3 +115,4 @@ test: serializable-parallel-2
test: serializable-parallel-3
test: matview-write-skew
test: lock-nowait
+test: session-variable
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
new file mode 100644
index 00000000000..c864fee4006
--- /dev/null
+++ b/src/test/isolation/specs/session-variable.spec
@@ -0,0 +1,50 @@
+# Test session variables memory cleanup for sinval
+
+setup
+{
+ CREATE VARIABLE myvar AS text;
+}
+
+teardown
+{
+ DROP VARIABLE IF EXISTS myvar;
+}
+
+session s1
+step s1 { BEGIN; }
+step let { LET myvar = 'test'; }
+step val { SELECT myvar; }
+step dbg { SELECT schema, name, removed FROM pg_session_variables(); }
+step sr1 { ROLLBACK; }
+
+session s2
+step drop { DROP VARIABLE myvar; }
+step create { CREATE VARIABLE myvar AS text; }
+
+session s3
+step s3 { BEGIN; }
+step let3 { LET myvar3 = 'test'; }
+step create4 { CREATE VARIABLE myvar4 AS text; }
+step let4 { LET myvar4 = 'test'; }
+step drop4 { DROP VARIABLE myvar4; }
+step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; }
+step discard { DISCARD VARIABLES; }
+step sc3 { COMMIT; }
+step state { SELECT varname FROM pg_variable; }
+
+session s4
+step create3 { CREATE VARIABLE myvar3 AS text; }
+step drop3 { DROP VARIABLE myvar3; }
+
+# Concurrent drop of a known variable should lead to an error
+permutation let val drop val
+# Same, but with an explicit transaction
+permutation let val s1 drop val sr1
+# Concurrent drop/create of a known variable should lead to empty variable
+permutation let val dbg drop create dbg val
+# Concurrent drop/create of a known variable should lead to empty variable
+# We need a transaction to make sure that we won't accept invalidation when
+# calling the dbg step after the concurrent drop
+permutation let val s1 dbg drop create dbg val sr1
+# test for DISCARD ALL when all internal queues have actions registered
+permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 79ac40768f8..2783caa8446 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1726,3 +1726,220 @@ SELECT count(*) FROM pg_session_variables();
0
(1 row)
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+-- should fail
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1, var2;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 2954759aaed..a624ab8b67f 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1214,3 +1214,123 @@ DISCARD VARIABLES;
-- should be zero again
SELECT count(*) FROM pg_session_variables();
+
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+
+-- should fail
+SELECT var1;
+
+ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ROLLBACK;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+DROP VARIABLE var1, var2;
--
2.48.1
[text/x-patch] v20250317-0004-DISCARD-VARIABLES.patch (9.6K, ../../CAFj8pRC_2tHski1K4hUMZm0+T4y7na4d8hwgMMF7Y0MXhfUhbg@mail.gmail.com/6-v20250317-0004-DISCARD-VARIABLES.patch)
download | inline diff:
From 97e5fdb57c6861b8f57ac4c33637b568eee8471b Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sun, 28 Jan 2024 20:54:20 +0100
Subject: [PATCH 04/21] DISCARD VARIABLES
Implementation of DISCARD VARIABLES commands by removing hash table with session variables
and resetting related memory context.
---
doc/src/sgml/ref/discard.sgml | 13 +++-
src/backend/commands/discard.c | 6 ++
src/backend/commands/session_variable.c | 28 ++++++++-
src/backend/parser/gram.y | 6 ++
src/backend/tcop/utility.c | 3 +
src/bin/psql/tab-complete.in.c | 2 +-
src/include/commands/session_variable.h | 2 +
src/include/nodes/parsenodes.h | 1 +
src/include/tcop/cmdtaglist.h | 1 +
.../regress/expected/session_variables.out | 63 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 36 +++++++++++
11 files changed, 158 insertions(+), 3 deletions(-)
diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
index bf44c523cac..61b967f9c9b 100644
--- a/doc/src/sgml/ref/discard.sgml
+++ b/doc/src/sgml/ref/discard.sgml
@@ -21,7 +21,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
+DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES }
</synopsis>
</refsynopsisdiv>
@@ -66,6 +66,16 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>VARIABLES</literal></term>
+ <listitem>
+ <para>
+ Resets the value of all session variables. If a variable
+ is later reused, it is re-initialized to <literal>NULL</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><literal>TEMPORARY</literal> or <literal>TEMP</literal></term>
<listitem>
@@ -93,6 +103,7 @@ SELECT pg_advisory_unlock_all();
DISCARD PLANS;
DISCARD TEMP;
DISCARD SEQUENCES;
+DISCARD VARIABLES;
</programlisting></para>
</listitem>
</varlistentry>
diff --git a/src/backend/commands/discard.c b/src/backend/commands/discard.c
index 81339a75a52..5904a6c4917 100644
--- a/src/backend/commands/discard.c
+++ b/src/backend/commands/discard.c
@@ -18,6 +18,7 @@
#include "commands/async.h"
#include "commands/discard.h"
#include "commands/prepare.h"
+#include "commands/session_variable.h"
#include "commands/sequence.h"
#include "utils/guc.h"
#include "utils/portal.h"
@@ -48,6 +49,10 @@ DiscardCommand(DiscardStmt *stmt, bool isTopLevel)
ResetTempTableNamespace();
break;
+ case DISCARD_VARIABLES:
+ ResetSessionVariables();
+ break;
+
default:
elog(ERROR, "unrecognized DISCARD target: %d", stmt->target);
}
@@ -75,4 +80,5 @@ DiscardAll(bool isTopLevel)
ResetPlanCache();
ResetTempTableNamespace();
ResetSequenceCaches();
+ ResetSessionVariables();
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index fa16f47072e..e1c86966998 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -94,7 +94,13 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
- Assert(sessionvars);
+ /*
+ * There is no guarantee of session variables being initialized, even when
+ * receiving an invalidation callback, as DISCARD [ ALL | VARIABLES ]
+ * destroys the hash table entirely.
+ */
+ if (!sessionvars)
+ return;
/*
* If the hashvalue is not specified, we have to recheck all currently
@@ -619,3 +625,23 @@ pg_session_variables(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+
+/*
+ * Fast drop of the complete content of the session variables hash table, and
+ * cleanup of any list that wouldn't be relevant anymore.
+ * This is used by the DISCARD VARIABLES (and DISCARD ALL) command.
+ */
+void
+ResetSessionVariables(void)
+{
+ /* destroy hash table and reset related memory context */
+ if (sessionvars)
+ {
+ hash_destroy(sessionvars);
+ sessionvars = NULL;
+ }
+
+ /* release memory allocated by session variables */
+ if (SVariableMemoryContext != NULL)
+ MemoryContextReset(SVariableMemoryContext);
+}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 58347b296fc..81ae5274ec6 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -2084,7 +2084,13 @@ DiscardStmt:
n->target = DISCARD_SEQUENCES;
$$ = (Node *) n;
}
+ | DISCARD VARIABLES
+ {
+ DiscardStmt *n = makeNode(DiscardStmt);
+ n->target = DISCARD_VARIABLES;
+ $$ = (Node *) n;
+ }
;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 7a508a3644f..6e4d2310f5c 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -2962,6 +2962,9 @@ CreateCommandTag(Node *parsetree)
case DISCARD_SEQUENCES:
tag = CMDTAG_DISCARD_SEQUENCES;
break;
+ case DISCARD_VARIABLES:
+ tag = CMDTAG_DISCARD_VARIABLES;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index dfe821f4b60..c0f540a4b8f 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4142,7 +4142,7 @@ match_previous_words(int pattern_id,
/* DISCARD */
else if (Matches("DISCARD"))
- COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP");
+ COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP", "VARIABLES");
/* DO */
else if (Matches("DO"))
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index 2391b9ad443..a8ca43c87af 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -27,4 +27,6 @@ extern Datum GetSessionVariable(Oid varid, bool *isNull);
extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
QueryEnvironment *queryEnv, QueryCompletion *qc);
+extern void ResetSessionVariables(void);
+
#endif
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index a21d1d2e99f..33d03c8f174 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -4049,6 +4049,7 @@ typedef enum DiscardMode
DISCARD_PLANS,
DISCARD_SEQUENCES,
DISCARD_TEMP,
+ DISCARD_VARIABLES,
} DiscardMode;
typedef struct DiscardStmt
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index 22082c30008..bef0ac25331 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -135,6 +135,7 @@ PG_CMDTAG(CMDTAG_DISCARD_ALL, "DISCARD ALL", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_PLANS, "DISCARD PLANS", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_SEQUENCES, "DISCARD SEQUENCES", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_TEMP, "DISCARD TEMP", false, false, false)
+PG_CMDTAG(CMDTAG_DISCARD_VARIABLES, "DISCARD VARIABLES", false, false, false)
PG_CMDTAG(CMDTAG_DO, "DO", false, false, false)
PG_CMDTAG(CMDTAG_DROP_ACCESS_METHOD, "DROP ACCESS METHOD", true, false, false)
PG_CMDTAG(CMDTAG_DROP_AGGREGATE, "DROP AGGREGATE", true, false, false)
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index f22467186e3..79ac40768f8 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1663,3 +1663,66 @@ DROP VARIABLE :"DBNAME".:"DBNAME".b;
DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+ var1
+-------
+ Hello
+(1 row)
+
+DISCARD ALL;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT var1;
+ var1
+------
+ AHOJ
+(1 row)
+
+DISCARD VARIABLES;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+DROP VARIABLE var1;
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS varchar;
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DISCARD VARIABLES;
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index e72360d5254..2954759aaed 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1178,3 +1178,39 @@ DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+
+DISCARD ALL;
+SELECT var1;
+
+LET var1 = 'AHOJ';
+SELECT var1;
+
+DISCARD VARIABLES;
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+
+SELECT count(*) FROM pg_session_variables();
+
+CREATE VARIABLE var1 AS varchar;
+
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+
+LET var1 = 'AHOJ';
+
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+
+DISCARD VARIABLES;
+
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
--
2.48.1
[text/x-patch] v20250317-0006-plpgsql-tests.patch (16.9K, ../../CAFj8pRC_2tHski1K4hUMZm0+T4y7na4d8hwgMMF7Y0MXhfUhbg@mail.gmail.com/7-v20250317-0006-plpgsql-tests.patch)
download | inline diff:
From 86e8a482867cc6b67a89d67f76bccdde9c62b4c2 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 14:06:06 +0100
Subject: [PATCH 06/21] plpgsql tests
---
src/pl/plpgsql/src/Makefile | 3 +-
.../src/expected/plpgsql_session_variable.out | 382 ++++++++++++++++++
src/pl/plpgsql/src/meson.build | 1 +
.../src/sql/plpgsql_session_variable.sql | 289 +++++++++++++
4 files changed, 674 insertions(+), 1 deletion(-)
create mode 100644 src/pl/plpgsql/src/expected/plpgsql_session_variable.out
create mode 100644 src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile
index 63cb96fae3e..bbcae27d422 100644
--- a/src/pl/plpgsql/src/Makefile
+++ b/src/pl/plpgsql/src/Makefile
@@ -35,7 +35,8 @@ REGRESS_OPTS = --dbname=$(PL_TESTDB)
REGRESS = plpgsql_array plpgsql_cache plpgsql_call plpgsql_control \
plpgsql_copy plpgsql_domain plpgsql_misc \
plpgsql_record plpgsql_simple plpgsql_transaction \
- plpgsql_trap plpgsql_trigger plpgsql_varprops
+ plpgsql_trap plpgsql_trigger plpgsql_varprops \
+ plpgsql_session_variable
# where to find gen_keywordlist.pl and subsidiary files
TOOLSDIR = $(top_srcdir)/src/tools
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
new file mode 100644
index 00000000000..ab779900596
--- /dev/null
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -0,0 +1,382 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+LET plpgsql_sv_var = pi();
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+NOTICE: value of session variable is 3.14159265358979
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+ pi_multiply_2
+------------------
+ 6.28318530717959
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var;
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+END;
+-- execute outside of a transaction
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP FUNCTION test_func();
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+SET ROLE TO regress_var_owner_role;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_reader_role;
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail
+SELECT var_read_func();
+ERROR: permission denied for session variable plpgsql_sv_var1
+CONTEXT: PL/pgSQL expression "plpgsql_sv_var1"
+PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should be ok
+SELECT var_read_func();
+NOTICE: 10
+ var_read_func
+---------------
+
+(1 row)
+
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+DROP VARIABLE plpgsql_sv_var1;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail, but not crash
+SELECT var_read_func();
+ERROR: column "plpgsql_sv_var1" does not exist
+LINE 1: plpgsql_sv_var1
+ ^
+QUERY: plpgsql_sv_var1
+CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+DROP FUNCTION var_read_func;
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+ inc_var_int
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+LET plpgsql_sv_var2 = 0.0;
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+ inc_var_num
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+NOTICE: variable is 1000
+DROP VARIABLE plpgsql_sv_var1;
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+select ffunc();
+ ffunc
+-------
+ abc
+(1 row)
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+DROP VARIABLE plpgsql_sv_v;
diff --git a/src/pl/plpgsql/src/meson.build b/src/pl/plpgsql/src/meson.build
index 33c49ac25d9..1d01d1c2629 100644
--- a/src/pl/plpgsql/src/meson.build
+++ b/src/pl/plpgsql/src/meson.build
@@ -88,6 +88,7 @@ tests += {
'plpgsql_trap',
'plpgsql_trigger',
'plpgsql_varprops',
+ 'plpgsql_session_variable',
],
},
}
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
new file mode 100644
index 00000000000..a3cc264cf38
--- /dev/null
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -0,0 +1,289 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+
+LET plpgsql_sv_var = pi();
+
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+
+DROP VARIABLE plpgsql_sv_var;
+
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+END;
+
+-- execute outside of a transaction
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+SELECT test_func();
+
+DROP FUNCTION test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+SET ROLE TO regress_var_owner_role;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_reader_role;
+
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should be ok
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail, but not crash
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+DROP FUNCTION var_read_func;
+
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+
+LET plpgsql_sv_var2 = 0.0;
+
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+
+select ffunc();
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+
+DROP VARIABLE plpgsql_sv_v;
--
2.48.1
[text/x-patch] v20250317-0001-Enhancing-catalog-for-support-session-variables-and-.patch (169.3K, ../../CAFj8pRC_2tHski1K4hUMZm0+T4y7na4d8hwgMMF7Y0MXhfUhbg@mail.gmail.com/8-v20250317-0001-Enhancing-catalog-for-support-session-variables-and-.patch)
download | inline diff:
From 1527fabae1e47432ff60d0b8bb40fc54f19e1ef3 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 15:41:55 +0100
Subject: [PATCH 01/21] Enhancing catalog for support session variables and
related support
This patch introduces new system catalog table pg_variable. This table holds metadata about
session variables created by command CREATE VARIABLE, and dropped by command DROP VARIABLE.
Both commands are implemented by this patch. Possibility to change owner, schema or rename.
Access to session variables can be controlled by SELECT or UPDATE rights. Both rights are
introduced by this patch too.
This patch enhancing pg_dump and psql to support session variables. The changes are related
to system catalog.
This patch is not short, but the code is simple.
---
doc/src/sgml/catalogs.sgml | 123 ++++-
doc/src/sgml/ddl.sgml | 40 +-
doc/src/sgml/func.sgml | 32 ++
doc/src/sgml/glossary.sgml | 15 +
doc/src/sgml/ref/allfiles.sgml | 3 +
.../sgml/ref/alter_default_privileges.sgml | 27 +-
doc/src/sgml/ref/alter_variable.sgml | 178 +++++++
doc/src/sgml/ref/comment.sgml | 1 +
doc/src/sgml/ref/create_schema.sgml | 12 +-
doc/src/sgml/ref/create_variable.sgml | 149 ++++++
doc/src/sgml/ref/drop_variable.sgml | 117 +++++
doc/src/sgml/ref/grant.sgml | 20 +-
doc/src/sgml/ref/psql-ref.sgml | 13 +
doc/src/sgml/ref/revoke.sgml | 8 +
doc/src/sgml/reference.sgml | 3 +
src/backend/catalog/Makefile | 1 +
src/backend/catalog/aclchk.c | 77 ++++
src/backend/catalog/dependency.c | 6 +
src/backend/catalog/meson.build | 1 +
src/backend/catalog/namespace.c | 221 +++++++++
src/backend/catalog/objectaddress.c | 121 ++++-
src/backend/catalog/pg_shdepend.c | 2 +
src/backend/catalog/pg_variable.c | 251 ++++++++++
src/backend/commands/alter.c | 9 +
src/backend/commands/dropcmds.c | 4 +
src/backend/commands/event_trigger.c | 4 +
src/backend/commands/seclabel.c | 1 +
src/backend/commands/tablecmds.c | 41 ++
src/backend/commands/typecmds.c | 15 +
src/backend/parser/gram.y | 105 ++++-
src/backend/parser/parse_utilcmd.c | 12 +
src/backend/tcop/utility.c | 20 +
src/backend/utils/adt/acl.c | 221 +++++++++
src/backend/utils/cache/lsyscache.c | 113 +++++
src/bin/pg_dump/common.c | 3 +
src/bin/pg_dump/dumputils.c | 6 +
src/bin/pg_dump/pg_backup.h | 2 +
src/bin/pg_dump/pg_backup_archiver.c | 9 +
src/bin/pg_dump/pg_dump.c | 190 ++++++++
src/bin/pg_dump/pg_dump.h | 15 +
src/bin/pg_dump/pg_dump_sort.c | 7 +
src/bin/pg_dump/t/002_pg_dump.pl | 64 +++
src/bin/psql/command.c | 3 +
src/bin/psql/describe.c | 100 +++-
src/bin/psql/describe.h | 3 +
src/bin/psql/help.c | 1 +
src/bin/psql/tab-complete.in.c | 43 +-
src/include/catalog/Makefile | 3 +-
src/include/catalog/meson.build | 1 +
src/include/catalog/namespace.h | 6 +
src/include/catalog/pg_default_acl.h | 1 +
src/include/catalog/pg_proc.dat | 23 +
src/include/catalog/pg_variable.h | 81 ++++
src/include/nodes/parsenodes.h | 16 +
src/include/parser/kwlist.h | 2 +
src/include/tcop/cmdtaglist.h | 3 +
src/include/utils/acl.h | 1 +
src/include/utils/lsyscache.h | 9 +
src/test/regress/expected/dependency.out | 17 +
src/test/regress/expected/oidjoins.out | 4 +
src/test/regress/expected/psql.out | 50 ++
.../regress/expected/session_variables.out | 433 ++++++++++++++++++
src/test/regress/parallel_schedule | 2 +-
src/test/regress/sql/dependency.sql | 14 +
src/test/regress/sql/psql.sql | 21 +
src/test/regress/sql/session_variables.sql | 297 ++++++++++++
src/tools/pgindent/typedefs.list | 4 +
67 files changed, 3364 insertions(+), 36 deletions(-)
create mode 100644 doc/src/sgml/ref/alter_variable.sgml
create mode 100644 doc/src/sgml/ref/create_variable.sgml
create mode 100644 doc/src/sgml/ref/drop_variable.sgml
create mode 100644 src/backend/catalog/pg_variable.c
create mode 100644 src/include/catalog/pg_variable.h
create mode 100644 src/test/regress/expected/session_variables.out
create mode 100644 src/test/regress/sql/session_variables.sql
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index fb050635551..8321b453e2c 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -369,6 +369,11 @@
<entry><link linkend="catalog-pg-user-mapping"><structname>pg_user_mapping</structname></link></entry>
<entry>mappings of users to foreign servers</entry>
</row>
+
+ <row>
+ <entry><link linkend="catalog-pg-variable"><structname>pg_variable</structname></link></entry>
+ <entry>session variables</entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -3361,7 +3366,8 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
<literal>S</literal> = sequence,
<literal>f</literal> = function,
<literal>T</literal> = type,
- <literal>n</literal> = schema
+ <literal>n</literal> = schema,
+ <literal>V</literal> = session variable
</para></entry>
</row>
@@ -9779,4 +9785,119 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</table>
</sect1>
+ <sect1 id="catalog-pg-variable">
+ <title><structname>pg_variable</structname></title>
+
+ <indexterm zone="catalog-pg-variable">
+ <primary>pg_variable</primary>
+ </indexterm>
+
+ <para>
+ The catalog <structname>pg_variable</structname> stores information about
+ session variables.
+ </para>
+
+ <table>
+ <title><structname>pg_variable</structname> Columns</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ Column Type
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>oid</structfield> <type>oid</type>
+ </para>
+ <para>
+ Row identifier
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartype</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-type"><structname>pg_type</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the variable's data type
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varname</structfield> <type>name</type>
+ </para>
+ <para>
+ Name of the session variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varnamespace</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the namespace that contains this variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varowner</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ Owner of the variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartypmod</structfield> <type>int4</type>
+ </para>
+ <para>
+ <structfield>vartypmod</structfield> records type-specific data
+ supplied at variable creation time (for example, the maximum
+ length of a <type>varchar</type> column). It is passed to
+ type-specific input functions and length coercion functions.
+ The value will generally be -1 for types that do not need <structfield>vartypmod</structfield>.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcollation</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-collation"><structname>pg_collation</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The defined collation of the variable, or zero if the variable is
+ not of a collatable data type.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varacl</structfield> <type>aclitem[]</type>
+ </para>
+ <para>
+ Access privileges; see
+ <xref linkend="sql-grant"/> and
+ <xref linkend="sql-revoke"/>
+ for details
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+ </sect1>
</chapter>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index cdb1a07e9d3..aca13a9e2e6 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -2018,6 +2018,7 @@ REVOKE ALL ON accounts FROM PUBLIC;
For sequences, this privilege also allows use of the
<function>currval</function> function.
For large objects, this privilege allows the object to be read.
+ For session variables, this privilege allows the object to be read.
</para>
</listitem>
</varlistentry>
@@ -2053,6 +2054,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<function>setval</function> functions.
For large objects, this privilege allows writing or truncating the
object.
+ For session variables, this privilege allows to set a value to the
+ object.
</para>
</listitem>
</varlistentry>
@@ -2296,7 +2299,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal> (and table-like objects),
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2311,7 +2315,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal>,
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2498,6 +2503,12 @@ REVOKE ALL ON accounts FROM PUBLIC;
<entry><literal>U</literal></entry>
<entry><literal>\dT+</literal></entry>
</row>
+ <row>
+ <entry><literal>SESSION VARIABLE</literal></entry>
+ <entry><literal>rw</literal></entry>
+ <entry><literal>none</literal></entry>
+ <entry><literal>\dV+</literal></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -5348,6 +5359,31 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
</para>
</sect1>
+ <sect1 id="ddl-session-variables">
+ <title>Session Variables</title>
+
+ <indexterm zone="ddl-session-variables">
+ <primary>Session variables</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ </indexterm>
+
+ <para>
+ Session variables are database objects that can hold a value.
+ Session variables, like relations, exist within a schema and their access
+ is controlled via <command>GRANT</command> and <command>REVOKE</command>
+ commands. A session variable can be created by the <command>CREATE
+ VARIABLE</command> command.
+ </para>
+
+ <para>
+ The session variable holds value in session memory. This value is private
+ to each session and is released when the session ends.
+ </para>
+ </sect1>
+
<sect1 id="ddl-others">
<title>Other Database Objects</title>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 1c3810e1a04..a323215741a 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25493,6 +25493,25 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
</para></entry>
</row>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>has_session_variable_privilege</primary>
+ </indexterm>
+ <function>has_session_variable_privilege</function> (
+ <optional> <parameter>user</parameter> <type>name</type> or <type>oid</type>, </optional>
+ <parameter>session_variable</parameter> <type>text</type> or <type>oid</type>,
+ <parameter>privilege</parameter> <type>text</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Does user have privilege for session variable?
+ Allowable privilege types are
+ <literal>SELECT</literal>, and
+ <literal>UPDATE</literal>.
+ </para></entry>
+ </row>
+
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
@@ -26001,6 +26020,19 @@ SELECT relname FROM pg_class WHERE pg_table_is_visible(oid);
Is type (or domain) visible in search path?
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_variable_is_visible</primary>
+ </indexterm>
+ <function>pg_variable_is_visible</function> ( <parameter>variable</parameter> <type>oid</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Is session variable visible in search path?
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index c0f812e3f5e..b921f5a3339 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1669,6 +1669,21 @@
</glossdef>
</glossentry>
+ <glossentry id="glossary-session-variable">
+ <glossterm>Session variable</glossterm>
+ <glossdef>
+ <para>
+ A persistent database object that holds a value in session memory. This
+ value is private to each session and is released when the session ends.
+ Read or write access to session variables is controlled by privileges,
+ similar to other database objects.
+ </para>
+ <para>
+ For more information, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </glossdef>
+ </glossentry>
+
<glossentry id="glossary-shared-memory">
<glossterm>Shared memory</glossterm>
<glossdef>
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index f5be638867a..2f67de3e21b 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -47,6 +47,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY alterType SYSTEM "alter_type.sgml">
<!ENTITY alterUser SYSTEM "alter_user.sgml">
<!ENTITY alterUserMapping SYSTEM "alter_user_mapping.sgml">
+<!ENTITY alterVariable SYSTEM "alter_variable.sgml">
<!ENTITY alterView SYSTEM "alter_view.sgml">
<!ENTITY analyze SYSTEM "analyze.sgml">
<!ENTITY begin SYSTEM "begin.sgml">
@@ -99,6 +100,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY createType SYSTEM "create_type.sgml">
<!ENTITY createUser SYSTEM "create_user.sgml">
<!ENTITY createUserMapping SYSTEM "create_user_mapping.sgml">
+<!ENTITY createVariable SYSTEM "create_variable.sgml">
<!ENTITY createView SYSTEM "create_view.sgml">
<!ENTITY deallocate SYSTEM "deallocate.sgml">
<!ENTITY declare SYSTEM "declare.sgml">
@@ -147,6 +149,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY dropType SYSTEM "drop_type.sgml">
<!ENTITY dropUser SYSTEM "drop_user.sgml">
<!ENTITY dropUserMapping SYSTEM "drop_user_mapping.sgml">
+<!ENTITY dropVariable SYSTEM "drop_variable.sgml">
<!ENTITY dropView SYSTEM "drop_view.sgml">
<!ENTITY end SYSTEM "end.sgml">
<!ENTITY execute SYSTEM "execute.sgml">
diff --git a/doc/src/sgml/ref/alter_default_privileges.sgml b/doc/src/sgml/ref/alter_default_privileges.sgml
index 89aacec4fab..a5852d32566 100644
--- a/doc/src/sgml/ref/alter_default_privileges.sgml
+++ b/doc/src/sgml/ref/alter_default_privileges.sgml
@@ -51,6 +51,11 @@ GRANT { { USAGE | CREATE }
ON SCHEMAS
TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+GRANT { { SELECT | UPDATE }
+ [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+
REVOKE [ GRANT OPTION FOR ]
{ { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER | MAINTAIN }
[, ...] | ALL [ PRIVILEGES ] }
@@ -83,6 +88,12 @@ REVOKE [ GRANT OPTION FOR ]
ON SCHEMAS
FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
[ CASCADE | RESTRICT ]
+
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
+ [ CASCADE | RESTRICT ]
</synopsis>
</refsynopsisdiv>
@@ -117,14 +128,14 @@ REVOKE [ GRANT OPTION FOR ]
<para>
Currently,
only the privileges for schemas, tables (including views and foreign
- tables), sequences, functions, and types (including domains) can be
- altered. For this command, functions include aggregates and procedures.
- The words <literal>FUNCTIONS</literal> and <literal>ROUTINES</literal> are
- equivalent in this command. (<literal>ROUTINES</literal> is preferred
- going forward as the standard term for functions and procedures taken
- together. In earlier PostgreSQL releases, only the
- word <literal>FUNCTIONS</literal> was allowed. It is not possible to set
- default privileges for functions and procedures separately.)
+ tables), sequences, functions, types (including domains), and session
+ variables can be altered. For this command, functions include aggregates
+ and procedures. The words <literal>FUNCTIONS</literal> and
+ <literal>ROUTINES</literal> are equivalent in this command.
+ (<literal>ROUTINES</literal> is preferred going forward as the standard
+ term for functions and procedures taken together. In earlier PostgreSQL
+ releases, only the word <literal>FUNCTIONS</literal> was allowed. It is not
+ possible to set default privileges for functions and procedures separately.)
</para>
<para>
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
new file mode 100644
index 00000000000..96d2586423e
--- /dev/null
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -0,0 +1,178 @@
+<!--
+doc/src/sgml/ref/alter_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-altervariable">
+ <indexterm zone="sql-altervariable">
+ <primary>ALTER VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>altering</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>ALTER VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>ALTER VARIABLE</refname>
+ <refpurpose>
+ change the definition of a session variable
+ </refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable class="parameter">new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable class="parameter">new_name</replaceable>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> SET SCHEMA <replaceable class="parameter">new_schema</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>ALTER VARIABLE</command> command changes the definition of an
+ existing session variable. There are several subforms:
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>OWNER</literal></term>
+ <listitem>
+ <para>
+ This form changes the owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RENAME</literal></term>
+ <listitem>
+ <para>
+ This form changes the name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>SET SCHEMA</literal></term>
+ <listitem>
+ <para>
+ This form moves the session variable into another schema.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </para>
+
+ <para>
+ Only the owner or a superuser is allowed to alter a session variable.
+ In order to move a session variable from one schema to another, the user
+ must also have the <literal>CREATE</literal> privilege on the new schema (or
+ be a superuser).
+
+ In order to move the session variable ownership from one role to another,
+ the user must also be a direct or indirect member of the new
+ owning role, and that role must have the <literal>CREATE</literal> privilege
+ on the session variable's schema (or be a superuser). These restrictions
+ enforce that altering the owner doesn't do anything you couldn't do by
+ dropping and recreating the session variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <para>
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name (possibly schema-qualified) of the existing session variable
+ to alter.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_owner</replaceable></term>
+ <listitem>
+ <para>
+ The user name of the new owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_name</replaceable></term>
+ <listitem>
+ <para>
+ The new name for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_schema</replaceable></term>
+ <listitem>
+ <para>
+ The new schema for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To rename a session variable:
+<programlisting>
+ALTER VARIABLE foo RENAME TO boo;
+</programlisting>
+ </para>
+
+ <para>
+ To change the owner of the session variable <literal>boo</literal> to
+ <literal>joe</literal>:
+<programlisting>
+ALTER VARIABLE boo OWNER TO joe;
+</programlisting>
+ </para>
+
+ <para>
+ To change the schema of the session variable <literal>boo</literal> to
+ <literal>private</literal>:
+<programlisting>
+ALTER VARIABLE boo SET SCHEMA private;
+</programlisting>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ Session variables and this command in particular are a PostgreSQL extension.
+ </para>
+ </refsect1>
+
+ <refsect1 id="sql-altervariable-see-also">
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index 5b43c56b133..21cd80818fb 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -65,6 +65,7 @@ COMMENT ON
TRANSFORM FOR <replaceable>type_name</replaceable> LANGUAGE <replaceable>lang_name</replaceable> |
TRIGGER <replaceable class="parameter">trigger_name</replaceable> ON <replaceable class="parameter">table_name</replaceable> |
TYPE <replaceable class="parameter">object_name</replaceable> |
+ VARIABLE <replaceable class="parameter">object_name</replaceable> |
VIEW <replaceable class="parameter">object_name</replaceable>
} IS { <replaceable class="parameter">string_literal</replaceable> | NULL }
diff --git a/doc/src/sgml/ref/create_schema.sgml b/doc/src/sgml/ref/create_schema.sgml
index ed69298ccc6..d2bb265209b 100644
--- a/doc/src/sgml/ref/create_schema.sgml
+++ b/doc/src/sgml/ref/create_schema.sgml
@@ -103,9 +103,10 @@ CREATE SCHEMA IF NOT EXISTS AUTHORIZATION <replaceable class="parameter">role_sp
schema. Currently, only <command>CREATE
TABLE</command>, <command>CREATE VIEW</command>, <command>CREATE
INDEX</command>, <command>CREATE SEQUENCE</command>, <command>CREATE
- TRIGGER</command> and <command>GRANT</command> are accepted as clauses
- within <command>CREATE SCHEMA</command>. Other kinds of objects may
- be created in separate commands after the schema is created.
+ TRIGGER</command>, <command>GRANT</command> and <command>CREATE
+ VARIABLE</command> are accepted as clauses within <command>CREATE
+ SCHEMA</command>. Other kinds of objects may be created in separate
+ commands after the schema is created.
</para>
</listitem>
</varlistentry>
@@ -214,6 +215,11 @@ CREATE VIEW hollywood.winners AS
The <literal>IF NOT EXISTS</literal> option is a
<productname>PostgreSQL</productname> extension.
</para>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
</refsect1>
<refsect1>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
new file mode 100644
index 00000000000..6e988f2e472
--- /dev/null
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -0,0 +1,149 @@
+<!--
+doc/src/sgml/ref/create_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-createvariable">
+ <indexterm zone="sql-createvariable">
+ <primary>CREATE VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>defining</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>CREATE VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>CREATE VARIABLE</refname>
+ <refpurpose>define a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+</synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command creates a session variable.
+ Session variables, like relations, exist within a schema and their access is
+ controlled via the commands <command>GRANT</command> and <command>REVOKE</command>.
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a session variable's value returns NULL, unless its value is set to
+ something else in the current session with a <command>LET</command> command.
+ The content of a session variable is not transactional. This is the same as
+ regular variables in procedural languages.
+ </para>
+
+ <para>
+ Session variables are retrieved by the <command>SELECT</command>
+ command. Their value is set with the <command>LET</command> command.
+ </para>
+
+ <note>
+ <para>
+ Session variables can be <quote>shadowed</quote> by other identifiers.
+ For details, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </note>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+
+ <varlistentry id="sql-createvariable-if-not-exists">
+ <term><literal>IF NOT EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the name already exists. A notice is issued in
+ this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-name">
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-data_type">
+ <term><replaceable class="parameter">data_type</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the data type of the session
+ variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-collate">
+ <term><literal>COLLATE <replaceable>collation</replaceable></literal></term>
+ <listitem>
+ <para>
+ The <literal>COLLATE</literal> clause assigns a collation to the session
+ variable (which must be of a collatable data type). If not specified,
+ the data type's default collation is used.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para>
+ Use the <command>DROP VARIABLE</command> command to remove a session
+ variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ Create an date session variable <literal>var1</literal>:
+<programlisting>
+CREATE VARIABLE var1 AS date;
+</programlisting>
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
new file mode 100644
index 00000000000..5bdb3560f0b
--- /dev/null
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -0,0 +1,117 @@
+<!--
+doc/src/sgml/ref/drop_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-dropvariable">
+ <indexterm zone="sql-dropvariable">
+ <primary>DROP VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>removing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>DROP VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>DROP VARIABLE</refname>
+ <refpurpose>remove a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+DROP VARIABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ <command>DROP VARIABLE</command> removes a session variable.
+ A session variable can only be removed by its owner or a superuser.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>IF EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the session variable does not exist. A notice is
+ issued in this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of a session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>CASCADE</literal></term>
+ <listitem>
+ <para>
+ Automatically drop objects that depend on the session variable (such as
+ views), and in turn all objects that depend on those objects
+ (see <xref linkend="ddl-depend"/>).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RESTRICT</literal></term>
+ <listitem>
+ <para>
+ Refuse to drop the session variable if any objects depend on it. This is
+ the default.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To remove the session variable <literal>var1</literal>:
+
+<programlisting>
+DROP VARIABLE var1;
+</programlisting></para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>DROP VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index 999f657d5c0..c11860fa200 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -101,6 +101,12 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
[ WITH { ADMIN | INHERIT | SET } { OPTION | TRUE | FALSE } ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+GRANT { SELECT | UPDATE | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
@@ -119,8 +125,8 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
that grants privileges on a database object (table, column, view,
foreign table, sequence, database, foreign-data wrapper, foreign server,
function, procedure, procedural language, large object, configuration
- parameter, schema, tablespace, or type), and one that grants
- membership in a role. These variants are similar in many ways, but
+ parameter, schema, session variable, tablespace, or type), and one that
+ grants membership in a role. These variants are similar in many ways, but
they are different enough to be described separately.
</para>
@@ -236,9 +242,9 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
<para>
There is also an option to grant privileges on all objects of the same
type within one or more schemas. This functionality is currently supported
- only for tables, sequences, functions, and procedures. <literal>ALL
- TABLES</literal> also affects views and foreign tables, just like the
- specific-object <command>GRANT</command> command. <literal>ALL
+ only for tables, sequences, functions, procedures and variables.
+ <literal>ALL TABLES</literal> also affects views and foreign tables, just
+ like the specific-object <command>GRANT</command> command. <literal>ALL
FUNCTIONS</literal> also affects aggregate and window functions, but not
procedures, again just like the specific-object <command>GRANT</command>
command. Use <literal>ALL ROUTINES</literal> to include procedures.
@@ -518,8 +524,8 @@ GRANT admins TO joe;
</para>
<para>
- Privileges on databases, tablespaces, schemas, languages, and
- configuration parameters are
+ Privileges on databases, tablespaces, schemas, languages, session variables
+ and configuration parameters are
<productname>PostgreSQL</productname> extensions.
</para>
</refsect1>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..83abd7abb69 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -2135,6 +2135,19 @@ SELECT $1 \parse stmt1
</listitem>
</varlistentry>
+ <varlistentry id="app-psql-meta-command-dv">
+ <term><literal>\dV[+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
+ <listitem>
+ <para>
+ Lists session variables.
+ If <replaceable class="parameter">pattern</replaceable> is
+ specified, only session variables whose names match the pattern are listed.
+ If the form <literal>\dV+</literal> is used, additional information
+ about each variable is shown, like access privileges and description.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="app-psql-meta-command-du">
<term><literal>\du[Sx+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
<listitem>
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index 8df492281a1..760fddb7c20 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -130,6 +130,14 @@ REVOKE [ { ADMIN | INHERIT | SET } OPTION FOR ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
[ CASCADE | RESTRICT ]
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ FROM { <replaceable class="parameter">role_specification</replaceable> | PUBLIC } [, ...]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+ [ CASCADE | RESTRICT ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index ff85ace83fc..25578f3946c 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -75,6 +75,7 @@
&alterType;
&alterUser;
&alterUserMapping;
+ &alterVariable;
&alterView;
&analyze;
&begin;
@@ -127,6 +128,7 @@
&createType;
&createUser;
&createUserMapping;
+ &createVariable;
&createView;
&deallocate;
&declare;
@@ -175,6 +177,7 @@
&dropType;
&dropUser;
&dropUserMapping;
+ &dropVariable;
&dropView;
&end;
&execute;
diff --git a/src/backend/catalog/Makefile b/src/backend/catalog/Makefile
index c090094ed08..2c20d60db19 100644
--- a/src/backend/catalog/Makefile
+++ b/src/backend/catalog/Makefile
@@ -45,6 +45,7 @@ OBJS = \
pg_shdepend.o \
pg_subscription.o \
pg_type.o \
+ pg_variable.o \
storage.o \
toasting.o
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 02a754cc30a..1e8ce752b90 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -64,6 +64,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -291,6 +292,9 @@ restrict_and_check_grant(bool is_grant, AclMode avail_goptions, bool all_privs,
case OBJECT_PARAMETER_ACL:
whole_mask = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ whole_mask = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", objtype);
/* not reached, but keep compiler quiet */
@@ -535,6 +539,10 @@ ExecuteGrantStmt(GrantStmt *stmt)
all_privileges = ACL_ALL_RIGHTS_PARAMETER_ACL;
errormsg = gettext_noop("invalid privilege type %s for parameter");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) stmt->objtype);
@@ -640,6 +648,9 @@ ExecGrantStmt_oids(InternalGrant *istmt)
case OBJECT_PARAMETER_ACL:
ExecGrant_Parameter(istmt);
break;
+ case OBJECT_VARIABLE:
+ ExecGrant_common(istmt, VariableRelationId, ACL_ALL_RIGHTS_VARIABLE, NULL);
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) istmt->objtype);
@@ -760,6 +771,18 @@ objectNamesToOids(ObjectType objtype, List *objnames, bool is_grant)
objects = lappend_oid(objects, parameterId);
}
break;
+
+ case OBJECT_VARIABLE:
+ foreach_node(RangeVar, varvar, objnames)
+ {
+ Oid relOid;
+
+ relOid = LookupVariable(varvar->schemaname,
+ varvar->relname,
+ false);
+ objects = lappend_oid(objects, relOid);
+ }
+ break;
}
return objects;
@@ -846,6 +869,32 @@ objectsInSchemaToOids(ObjectType objtype, List *nspnames)
table_close(rel, AccessShareLock);
}
break;
+ case OBJECT_VARIABLE:
+ {
+ ScanKeyData key;
+ Relation rel;
+ TableScanDesc scan;
+ HeapTuple tuple;
+
+ ScanKeyInit(&key,
+ Anum_pg_variable_varnamespace,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(namespaceId));
+
+ rel = table_open(VariableRelationId, AccessShareLock);
+ scan = table_beginscan_catalog(rel, 1, &key);
+
+ while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+ {
+ Oid oid = ((Form_pg_proc) GETSTRUCT(tuple))->oid;
+
+ objects = lappend_oid(objects, oid);
+ }
+
+ table_endscan(scan);
+ table_close(rel, AccessShareLock);
+ }
+ break;
default:
/* should not happen */
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
@@ -1005,6 +1054,10 @@ ExecAlterDefaultPrivilegesStmt(ParseState *pstate, AlterDefaultPrivilegesStmt *s
all_privileges = ACL_ALL_RIGHTS_SCHEMA;
errormsg = gettext_noop("invalid privilege type %s for schema");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) action->objtype);
@@ -1196,6 +1249,12 @@ SetDefaultACL(InternalDefaultACL *iacls)
this_privileges = ACL_ALL_RIGHTS_SCHEMA;
break;
+ case OBJECT_VARIABLE:
+ objtype = DEFACLOBJ_VARIABLE;
+ if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
+ this_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ break;
+
default:
elog(ERROR, "unrecognized object type: %d",
(int) iacls->objtype);
@@ -1439,6 +1498,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case DEFACLOBJ_NAMESPACE:
iacls.objtype = OBJECT_SCHEMA;
break;
+ case DEFACLOBJ_VARIABLE:
+ iacls.objtype = OBJECT_VARIABLE;
+ break;
default:
/* Shouldn't get here */
elog(ERROR, "unexpected default ACL type: %d",
@@ -1499,6 +1561,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case ParameterAclRelationId:
istmt.objtype = OBJECT_PARAMETER_ACL;
break;
+ case VariableRelationId:
+ istmt.objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unexpected object class %u", classid);
break;
@@ -2732,6 +2797,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("permission denied for type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("permission denied for session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("permission denied for view %s");
break;
@@ -2843,6 +2911,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("must be owner of type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("must be owner of session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("must be owner of view %s");
break;
@@ -2991,6 +3062,8 @@ pg_aclmask(ObjectType objtype, Oid object_oid, AttrNumber attnum, Oid roleid,
return ACL_NO_RIGHTS;
case OBJECT_TYPE:
return object_aclmask(TypeRelationId, object_oid, roleid, mask, how);
+ case OBJECT_VARIABLE:
+ return object_aclmask(VariableRelationId, object_oid, roleid, mask, how);
default:
elog(ERROR, "unrecognized object type: %d",
(int) objtype);
@@ -4250,6 +4323,10 @@ get_user_default_acl(ObjectType objtype, Oid ownerId, Oid nsp_oid)
defaclobjtype = DEFACLOBJ_NAMESPACE;
break;
+ case OBJECT_VARIABLE:
+ defaclobjtype = DEFACLOBJ_VARIABLE;
+ break;
+
default:
return NULL;
}
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 18316a3968b..9e0f648b74f 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -65,12 +65,14 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/comment.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "commands/extension.h"
#include "commands/policy.h"
#include "commands/publicationcmds.h"
+#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
#include "commands/trigger.h"
@@ -1444,6 +1446,10 @@ doDeletion(const ObjectAddress *object, int flags)
RemovePublicationById(object->objectId);
break;
+ case VariableRelationId:
+ DropVariableById(object->objectId);
+ break;
+
case CastRelationId:
case CollationRelationId:
case ConversionRelationId:
diff --git a/src/backend/catalog/meson.build b/src/backend/catalog/meson.build
index 1958ea9238a..ed44c877fca 100644
--- a/src/backend/catalog/meson.build
+++ b/src/backend/catalog/meson.build
@@ -32,6 +32,7 @@ backend_sources += files(
'pg_shdepend.c',
'pg_subscription.c',
'pg_type.c',
+ 'pg_variable.c',
'storage.c',
'toasting.c',
)
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index d97d632a7ef..4307cad15c7 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "common/hashfn_unstable.h"
#include "funcapi.h"
@@ -225,6 +226,7 @@ static bool TSParserIsVisibleExt(Oid prsId, bool *is_missing);
static bool TSDictionaryIsVisibleExt(Oid dictId, bool *is_missing);
static bool TSTemplateIsVisibleExt(Oid tmplId, bool *is_missing);
static bool TSConfigIsVisibleExt(Oid cfgid, bool *is_missing);
+static bool VariableIsVisibleExt(Oid varid, bool *is_missing);
static void recomputeNamespacePath(void);
static void AccessTempTableNamespace(bool force);
static void InitTempTableNamespace(void);
@@ -986,6 +988,84 @@ RelationIsVisibleExt(Oid relid, bool *is_missing)
return visible;
}
+/*
+ * VariableIsVisible
+ * Determine whether a variable (identified by OID) is visible in the
+ * current search path. Visible means "would be found by searching
+ * for the unqualified variable name".
+ */
+bool
+VariableIsVisible(Oid varid)
+{
+ return VariableIsVisibleExt(varid, NULL);
+}
+
+/*
+ * VariableIsVisibleExt
+ * As above, but if the variable isn't found and is_missing is not NULL,
+ * then set *is_missing = true and return false, instead of throwing
+ * an error. (Caller must initialize *is_missing = false.)
+ */
+static bool
+VariableIsVisibleExt(Oid varid, bool *is_missing)
+{
+ HeapTuple vartup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+ bool visible;
+
+ vartup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+ if (!HeapTupleIsValid(vartup))
+ {
+ if (is_missing != NULL)
+ {
+ *is_missing = true;
+ return false;
+ }
+
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+ }
+ varform = (Form_pg_variable) GETSTRUCT(vartup);
+
+ recomputeNamespacePath();
+
+ /*
+ * Quick check: if it ain't in the path at all, it ain't visible. We
+ * don't expect usage of session variables in the system namespace.
+ */
+ varnamespace = varform->varnamespace;
+ if (!list_member_oid(activeSearchPath, varnamespace))
+ visible = false;
+ else
+ {
+ /*
+ * If it is in the path, it might still not be visible; it could be
+ * hidden by another variable of the same name earlier in the path. So
+ * we must do a slow check for conflicting relations.
+ */
+ char *varname = NameStr(varform->varname);
+
+ visible = false;
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ if (namespaceId == varnamespace)
+ {
+ /* found it first in path */
+ visible = true;
+ break;
+ }
+ if (OidIsValid(get_varname_varid(varname, namespaceId)))
+ {
+ /* found something else first in path */
+ break;
+ }
+ }
+ }
+
+ ReleaseSysCache(vartup);
+
+ return visible;
+}
/*
* TypenameGetTypid
@@ -3289,6 +3369,133 @@ TSConfigIsVisibleExt(Oid cfgid, bool *is_missing)
return visible;
}
+/*
+ * Returns oid of session variable specified by possibly qualified identifier.
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariable(const char *nspname,
+ const char *varname,
+ bool missing_ok)
+{
+ Oid varoid = InvalidOid;
+
+ if (nspname)
+ {
+ Oid namespaceId = LookupExplicitNamespace(nspname, missing_ok);
+
+ /* if nspname is a known namespace, the variable must be there */
+ if (OidIsValid(namespaceId))
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+ }
+ }
+ else
+ {
+ /* iterate over the schemas on the search_path */
+ recomputeNamespacePath();
+
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+
+ if (OidIsValid(varoid))
+ break;
+ }
+ }
+
+ if (!OidIsValid(varoid) && !missing_ok)
+ {
+ if (nspname)
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s.%s\" does not exist",
+ nspname, varname)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" does not exist",
+ varname)));
+ }
+
+ return varoid;
+}
+
+/*
+ * Returns oid of session variable specified by possibly qualified identifier
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariableFromNameList(List *names,
+ bool missing_ok)
+{
+ char *catname = NULL;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ switch (list_length(names))
+ {
+ case 1:
+ varname = strVal(linitial(names));
+ break;
+ case 2:
+ nspname = strVal(linitial(names));
+ varname = strVal(lsecond(names));
+ break;
+ case 3:
+ catname = strVal(linitial(names));
+ nspname = strVal(lsecond(names));
+ varname = strVal(lthird(names));
+
+ /* check catalog name */
+ if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ break;
+ default:
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper session variable name (too many dotted names): %s",
+ NameListToString(names))));
+ break;
+ }
+
+ return LookupVariable(nspname, varname, missing_ok);
+}
+
+/*
+ * The input list contains names with indirection expressions used as the left
+ * part of LET statement. The following routine returns a new list with only
+ * initial strings (names) - without indirection expressions.
+ */
+List *
+NamesFromList(List *names)
+{
+ ListCell *l;
+ List *result = NIL;
+
+ foreach(l, names)
+ {
+ Node *n = lfirst(l);
+
+ if (IsA(n, String))
+ {
+ result = lappend(result, n);
+ }
+ else
+ break;
+ }
+
+ return result;
+}
/*
* DeconstructQualifiedName
@@ -5085,3 +5292,17 @@ pg_is_other_temp_schema(PG_FUNCTION_ARGS)
PG_RETURN_BOOL(isOtherTempNamespace(oid));
}
+
+Datum
+pg_variable_is_visible(PG_FUNCTION_ARGS)
+{
+ Oid oid = PG_GETARG_OID(0);
+ bool result;
+ bool is_missing = false;
+
+ result = VariableIsVisibleExt(oid, &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+ PG_RETURN_BOOL(result);
+}
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index d8eb8d3deaa..4a464dfea7e 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -62,6 +62,7 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -636,6 +637,20 @@ static const ObjectPropertyType ObjectProperty[] =
OBJECT_USER_MAPPING,
false
},
+ {
+ "session variable",
+ VariableRelationId,
+ VariableOidIndexId,
+ VARIABLEOID,
+ VARIABLENAMENSP,
+ Anum_pg_variable_oid,
+ Anum_pg_variable_varname,
+ Anum_pg_variable_varnamespace,
+ Anum_pg_variable_varowner,
+ Anum_pg_variable_varacl,
+ OBJECT_VARIABLE,
+ true
+ }
};
/*
@@ -831,6 +846,9 @@ static const struct object_type_map
},
{
"statistics object", OBJECT_STATISTIC_EXT
+ },
+ {
+ "session variable", OBJECT_VARIABLE
}
};
@@ -856,6 +874,7 @@ static ObjectAddress get_object_address_attrdef(ObjectType objtype,
bool missing_ok);
static ObjectAddress get_object_address_type(ObjectType objtype,
TypeName *typename, bool missing_ok);
+static ObjectAddress get_object_address_variable(List *object, bool missing_ok);
static ObjectAddress get_object_address_opcf(ObjectType objtype, List *object,
bool missing_ok);
static ObjectAddress get_object_address_opf_member(ObjectType objtype,
@@ -1127,6 +1146,9 @@ get_object_address(ObjectType objtype, Node *object,
missing_ok);
address.objectSubId = 0;
break;
+ case OBJECT_VARIABLE:
+ address = get_object_address_variable(castNode(List, object), missing_ok);
+ break;
/* no default, to let compiler warn about missing case */
}
@@ -2005,16 +2027,20 @@ get_object_address_defacl(List *object, bool missing_ok)
case DEFACLOBJ_NAMESPACE:
objtype_str = "schemas";
break;
+ case DEFACLOBJ_VARIABLE:
+ objtype_str = "variables";
+ break;
default:
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized default ACL object type \"%c\"", objtype),
- errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
+ errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
DEFACLOBJ_RELATION,
DEFACLOBJ_SEQUENCE,
DEFACLOBJ_FUNCTION,
DEFACLOBJ_TYPE,
- DEFACLOBJ_NAMESPACE)));
+ DEFACLOBJ_NAMESPACE,
+ DEFACLOBJ_VARIABLE)));
}
/*
@@ -2098,6 +2124,24 @@ textarray_to_strvaluelist(ArrayType *arr)
return list;
}
+/*
+ * Find the ObjectAddress for a session variable
+ */
+static ObjectAddress
+get_object_address_variable(List *object, bool missing_ok)
+{
+ ObjectAddress address;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ ObjectAddressSet(address, VariableRelationId, InvalidOid);
+
+ DeconstructQualifiedName(object, &nspname, &varname);
+ address.objectId = LookupVariable(nspname, varname, missing_ok);
+
+ return address;
+}
+
/*
* SQL-callable version of get_object_address
*/
@@ -2292,6 +2336,7 @@ pg_get_object_address(PG_FUNCTION_ARGS)
case OBJECT_TABCONSTRAINT:
case OBJECT_OPCLASS:
case OBJECT_OPFAMILY:
+ case OBJECT_VARIABLE:
objnode = (Node *) name;
break;
case OBJECT_ACCESS_METHOD:
@@ -2463,6 +2508,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
case OBJECT_STATISTIC_EXT:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
if (!object_ownercheck(address.classId, address.objectId, roleid))
aclcheck_error(ACLCHECK_NOT_OWNER, objtype,
NameListToString(castNode(List, object)));
@@ -3492,6 +3538,32 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
break;
}
+ case VariableRelationId:
+ {
+ char *nspname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ if (VariableIsVisible(object->objectId))
+ nspname = NULL;
+ else
+ nspname = get_namespace_name(varform->varnamespace);
+
+ appendStringInfo(&buffer, _("session variable %s"),
+ quote_qualified_identifier(nspname,
+ NameStr(varform->varname)));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
case TSParserRelationId:
{
HeapTuple tup;
@@ -3844,6 +3916,16 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
_("default privileges on new schemas belonging to role %s"),
rolename);
break;
+ case DEFACLOBJ_VARIABLE:
+ if (nspname)
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s in schema %s"),
+ rolename, nspname);
+ else
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s"),
+ rolename);
+ break;
default:
/* shouldn't get here */
if (nspname)
@@ -4660,6 +4742,10 @@ getObjectTypeDescription(const ObjectAddress *object, bool missing_ok)
appendStringInfoString(&buffer, "transform");
break;
+ case VariableRelationId:
+ appendStringInfoString(&buffer, "session variable");
+ break;
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
@@ -5766,6 +5852,10 @@ getObjectIdentityParts(const ObjectAddress *object,
appendStringInfoString(&buffer,
" on schemas");
break;
+ case DEFACLOBJ_VARIABLE:
+ appendStringInfoString(&buffer,
+ " on session variables");
+ break;
}
if (objname)
@@ -6006,6 +6096,33 @@ getObjectIdentityParts(const ObjectAddress *object,
}
break;
+ case VariableRelationId:
+ {
+ char *schema;
+ char *varname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ schema = get_namespace_name_or_temp(varform->varnamespace);
+ varname = NameStr(varform->varname);
+
+ appendStringInfo(&buffer, "%s",
+ quote_qualified_identifier(schema, varname));
+
+ if (objname)
+ *objname = list_make2(schema, pstrdup(varname));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
diff --git a/src/backend/catalog/pg_shdepend.c b/src/backend/catalog/pg_shdepend.c
index 536191284e8..c6fd1fa074f 100644
--- a/src/backend/catalog/pg_shdepend.c
+++ b/src/backend/catalog/pg_shdepend.c
@@ -46,6 +46,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
@@ -1714,6 +1715,7 @@ shdepReassignOwned_Owner(Form_pg_shdepend sdepForm, Oid newrole)
case DatabaseRelationId:
case TSConfigRelationId:
case TSDictionaryRelationId:
+ case VariableRelationId:
AlterObjectOwner_internal(sdepForm->classid,
sdepForm->objid,
newrole);
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
new file mode 100644
index 00000000000..29d967a2d5b
--- /dev/null
+++ b/src/backend/catalog/pg_variable.c
@@ -0,0 +1,251 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.c
+ * session variables
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/catalog/pg_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "catalog/dependency.h"
+#include "catalog/indexing.h"
+#include "catalog/namespace.h"
+#include "catalog/objectaccess.h"
+#include "catalog/pg_collation.h"
+#include "catalog/pg_namespace.h"
+#include "catalog/pg_variable.h"
+#include "miscadmin.h"
+#include "parser/parse_type.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+static ObjectAddress create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists);
+
+
+/*
+ * Creates entry in pg_variable table
+ */
+static ObjectAddress
+create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists)
+{
+ Acl *varacl;
+ NameData varname;
+ bool nulls[Natts_pg_variable];
+ Datum values[Natts_pg_variable];
+ Relation rel;
+ HeapTuple tup;
+ TupleDesc tupdesc;
+ ObjectAddress myself,
+ referenced;
+ ObjectAddresses *addrs;
+ Oid varid;
+
+ Assert(varName);
+ Assert(OidIsValid(varNamespace));
+ Assert(OidIsValid(varType));
+ Assert(OidIsValid(varOwner));
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ /*
+ * Check for duplicates. Note that this does not really prevent
+ * duplicates, it's here just to provide nicer error message in common
+ * case. The real protection is the unique key on the catalog.
+ */
+ if (SearchSysCacheExists2(VARIABLENAMENSP,
+ PointerGetDatum(varName),
+ ObjectIdGetDatum(varNamespace)))
+ {
+ if (if_not_exists)
+ ereport(NOTICE,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists, skipping",
+ varName)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists",
+ varName)));
+
+ table_close(rel, RowExclusiveLock);
+
+ return InvalidObjectAddress;
+ }
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, false, sizeof(nulls));
+
+ namestrcpy(&varname, varName);
+
+ varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
+
+ values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
+ values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
+ values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
+ values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
+ values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
+ values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+
+ varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
+ varNamespace);
+ if (varacl != NULL)
+ values[Anum_pg_variable_varacl - 1] = PointerGetDatum(varacl);
+ else
+ nulls[Anum_pg_variable_varacl - 1] = true;
+
+ tupdesc = RelationGetDescr(rel);
+
+ tup = heap_form_tuple(tupdesc, values, nulls);
+ CatalogTupleInsert(rel, tup);
+ Assert(OidIsValid(varid));
+
+ addrs = new_object_addresses();
+
+ ObjectAddressSet(myself, VariableRelationId, varid);
+
+ /* dependency on namespace */
+ ObjectAddressSet(referenced, NamespaceRelationId, varNamespace);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on used type */
+ ObjectAddressSet(referenced, TypeRelationId, varType);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on collation */
+ if (OidIsValid(varCollation) &&
+ varCollation != DEFAULT_COLLATION_OID)
+ {
+ ObjectAddressSet(referenced, CollationRelationId, varCollation);
+ add_exact_object_address(&referenced, addrs);
+ }
+
+ record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
+ free_object_addresses(addrs);
+
+ /* dependency on owner */
+ recordDependencyOnOwner(VariableRelationId, varid, varOwner);
+
+ /* dependencies on roles mentioned in default ACL */
+ recordDependencyOnNewAcl(VariableRelationId, varid, 0, varOwner, varacl);
+
+ /* dependency on extension */
+ recordDependencyOnCurrentExtension(&myself, false);
+
+ heap_freetuple(tup);
+
+ /* post creation hook for new function */
+ InvokeObjectPostCreateHook(VariableRelationId, varid, 0);
+
+ table_close(rel, RowExclusiveLock);
+
+ return myself;
+}
+
+/*
+ * Creates a new variable
+ *
+ * Used by CREATE VARIABLE command
+ */
+ObjectAddress
+CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
+{
+ Oid namespaceid;
+ AclResult aclresult;
+ Oid typid;
+ int32 typmod;
+ Oid varowner = GetUserId();
+ Oid collation;
+ Oid typcollation;
+ ObjectAddress variable;
+
+ namespaceid =
+ RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL);
+
+ typenameTypeIdAndMod(pstate, stmt->typeName, &typid, &typmod);
+
+ /* disallow pseudotypes */
+ if (get_typtype(typid) == TYPTYPE_PSEUDO)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("session variable cannot be pseudo-type %s",
+ format_type_be(typid))));
+
+ aclresult = object_aclcheck(TypeRelationId, typid, GetUserId(), ACL_USAGE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error_type(aclresult, typid);
+
+ typcollation = get_typcollation(typid);
+
+ if (stmt->collClause)
+ collation = LookupCollation(pstate,
+ stmt->collClause->collname,
+ stmt->collClause->location);
+ else
+ collation = typcollation;
+
+ /* complain if COLLATE is applied to an uncollatable type */
+ if (OidIsValid(collation) && !OidIsValid(typcollation))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("collations are not supported by type %s",
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->collClause->location)));
+
+ variable = create_variable(stmt->variable->relname,
+ namespaceid,
+ typid,
+ typmod,
+ varowner,
+ collation,
+ stmt->if_not_exists);
+
+ elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
+ stmt->variable->relname, variable.objectId);
+
+ return variable;
+}
+
+/*
+ * Drop variable by OID
+ */
+void
+DropVariableById(Oid varid)
+{
+ Relation rel;
+ HeapTuple tup;
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ CatalogTupleDelete(rel, &tup->t_self);
+
+ ReleaseSysCache(tup);
+
+ table_close(rel, RowExclusiveLock);
+}
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index c801c869c1c..c72a4adb07b 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/collationcmds.h"
#include "commands/dbcommands.h"
@@ -140,6 +141,10 @@ report_namespace_conflict(Oid classId, const char *name, Oid nspOid)
Assert(OidIsValid(nspOid));
msgfmt = gettext_noop("text search configuration \"%s\" already exists in schema \"%s\"");
break;
+ case VariableRelationId:
+ Assert(OidIsValid(nspOid));
+ msgfmt = gettext_noop("session variable \"%s\" already exists in schema \"%s\"");
+ break;
default:
elog(ERROR, "unsupported object class: %u", classId);
break;
@@ -435,6 +440,7 @@ ExecRenameStmt(RenameStmt *stmt)
case OBJECT_TSTEMPLATE:
case OBJECT_PUBLICATION:
case OBJECT_SUBSCRIPTION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
Relation catalog;
@@ -575,6 +581,7 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt,
case OBJECT_TSDICTIONARY:
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
+ case OBJECT_VARIABLE:
{
Relation catalog;
Oid classId;
@@ -657,6 +664,7 @@ AlterObjectNamespace_oid(Oid classId, Oid objid, Oid nspOid,
case TSDictionaryRelationId:
case TSTemplateRelationId:
case TSConfigRelationId:
+ case VariableRelationId:
{
Relation catalog;
@@ -887,6 +895,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
case OBJECT_TABLESPACE:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
diff --git a/src/backend/commands/dropcmds.c b/src/backend/commands/dropcmds.c
index ceb9a229b63..ebb585dc4a1 100644
--- a/src/backend/commands/dropcmds.c
+++ b/src/backend/commands/dropcmds.c
@@ -476,6 +476,10 @@ does_not_exist_skipping(ObjectType objtype, Node *object)
msg = gettext_noop("publication \"%s\" does not exist, skipping");
name = strVal(object);
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("session variable \"%s\" does not exist, skipping");
+ name = NameListToString(castNode(List, object));
+ break;
case OBJECT_COLUMN:
case OBJECT_DATABASE:
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index edc2c988e29..1839c1f82c5 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -2149,6 +2149,8 @@ stringify_grant_objtype(ObjectType objtype)
return "TABLESPACE";
case OBJECT_TYPE:
return "TYPE";
+ case OBJECT_VARIABLE:
+ return "VARIABLE";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
@@ -2232,6 +2234,8 @@ stringify_adefprivs_objtype(ObjectType objtype)
return "TABLESPACES";
case OBJECT_TYPE:
return "TYPES";
+ case OBJECT_VARIABLE:
+ return "VARIABLES";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
diff --git a/src/backend/commands/seclabel.c b/src/backend/commands/seclabel.c
index cee5d7bbb9c..57b4e6719c2 100644
--- a/src/backend/commands/seclabel.c
+++ b/src/backend/commands/seclabel.c
@@ -92,6 +92,7 @@ SecLabelSupportsObjectType(ObjectType objtype)
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
case OBJECT_USER_MAPPING:
+ case OBJECT_VARIABLE:
return false;
/*
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 129c97fdf28..2b36103552d 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -52,6 +52,7 @@
#include "catalog/pg_tablespace.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "catalog/storage.h"
#include "catalog/storage_xlog.h"
#include "catalog/toasting.h"
@@ -6825,6 +6826,7 @@ ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
* (possibly nested several levels deep in composite types, arrays, etc!).
* Eventually, we'd like to propagate the check or rewrite operation
* into such tables, but for now, just error out if we find any.
+ * Also, check if "typeOid" is used as type of some session variable.
*
* Caller should provide either the associated relation of a rowtype,
* or a type name (not both) for use in the error message, if any.
@@ -6888,6 +6890,45 @@ find_composite_type_dependencies(Oid typeOid, Relation origRelation,
continue;
}
+ /* check if the type is used as type of some session variable */
+ if (pg_depend->classid == VariableRelationId)
+ {
+ Oid varid = pg_depend->objid;
+
+ if (origTypeName)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ origTypeName,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter foreign table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_RELATION ||
+ origRelation->rd_rel->relkind == RELKIND_MATVIEW ||
+ origRelation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+
+ continue;
+ }
+
/* Else, ignore dependees that aren't relations */
if (pg_depend->classid != RelationRelationId)
continue;
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 3cb3ca1cca1..473d98ff062 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -53,6 +53,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_range.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablecmds.h"
#include "commands/typecmds.h"
@@ -3369,6 +3370,20 @@ get_rels_with_domain(Oid domainOid, LOCKMODE lockmode)
}
continue;
}
+ else if (pg_depend->classid == VariableRelationId)
+ {
+ /*
+ * We cannot to validate constraint inside session variables
+ * from other sessions, so better to fail if there are any
+ * session variable, that use this domain.
+ */
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter domain \"%s\" because session variable \"%s.%s\" uses it",
+ domainTypeName,
+ get_namespace_name(get_session_variable_namespace(pg_depend->objid)),
+ get_session_variable_name(pg_depend->objid))));
+ }
/* Else, ignore dependees that aren't user columns of relations */
/* (we assume system columns are never of domain types) */
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 271ae26cbaf..d682c0f7b87 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -52,6 +52,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_am.h"
#include "catalog/pg_trigger.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/trigger.h"
#include "gramparse.h"
@@ -285,8 +286,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
ConstraintsSetStmt CopyStmt CreateAsStmt CreateCastStmt
CreateDomainStmt CreateExtensionStmt CreateGroupStmt CreateOpClassStmt
CreateOpFamilyStmt AlterOpFamilyStmt CreatePLangStmt
- CreateSchemaStmt CreateSeqStmt CreateStmt CreateStatsStmt CreateTableSpaceStmt
- CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
+ CreateSchemaStmt CreateSeqStmt CreateSessionVarStmt CreateStmt CreateStatsStmt
+ CreateTableSpaceStmt CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
CreateAssertionStmt CreateTransformStmt CreateTrigStmt CreateEventTrigStmt
CreateUserStmt CreateUserMappingStmt CreateRoleStmt CreatePolicyStmt
CreatedbStmt DeclareCursorStmt DefineStmt DeleteStmt DiscardStmt DoStmt
@@ -783,8 +784,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
UESCAPE UNBOUNDED UNCONDITIONAL UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN
UNLISTEN UNLOGGED UNTIL UPDATE USER USING
- VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
- VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
+ VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARIABLE
+ VARIABLES VARYING VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
@@ -1050,6 +1051,7 @@ stmt:
| CreatePolicyStmt
| CreatePLangStmt
| CreateSchemaStmt
+ | CreateSessionVarStmt
| CreateSeqStmt
| CreateStmt
| CreateSubscriptionStmt
@@ -1592,6 +1594,7 @@ schema_stmt:
| CreateTrigStmt
| GrantStmt
| ViewStmt
+ | CreateSessionVarStmt
;
@@ -5273,6 +5276,34 @@ create_extension_opt_item:
}
;
+/*****************************************************************************
+ *
+ * QUERY :
+ * CREATE VARIABLE varname [AS] type
+ *
+ *****************************************************************************/
+
+CreateSessionVarStmt:
+ CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $3;
+ n->typeName = $5;
+ n->collClause = (CollateClause *) $6;
+ n->if_not_exists = false;
+ $$ = (Node *) n;
+ }
+ | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $6;
+ n->typeName = $8;
+ n->collClause = (CollateClause *) $9;
+ n->if_not_exists = true;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
@@ -7064,6 +7095,7 @@ object_type_any_name:
| TEXT_P SEARCH DICTIONARY { $$ = OBJECT_TSDICTIONARY; }
| TEXT_P SEARCH TEMPLATE { $$ = OBJECT_TSTEMPLATE; }
| TEXT_P SEARCH CONFIGURATION { $$ = OBJECT_TSCONFIGURATION; }
+ | VARIABLE { $$ = OBJECT_VARIABLE; }
;
/*
@@ -7940,6 +7972,14 @@ privilege_target:
n->objs = $2;
$$ = n;
}
+ | VARIABLE qualified_name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_OBJECT;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $2;
+ $$ = n;
+ }
| ALL TABLES IN_P SCHEMA name_list
{
PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
@@ -7985,6 +8025,14 @@ privilege_target:
n->objs = $5;
$$ = n;
}
+ | ALL VARIABLES IN_P SCHEMA name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_ALL_IN_SCHEMA;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $5;
+ $$ = n;
+ }
;
@@ -8182,6 +8230,7 @@ defacl_privilege_target:
| SEQUENCES { $$ = OBJECT_SEQUENCE; }
| TYPES_P { $$ = OBJECT_TYPE; }
| SCHEMAS { $$ = OBJECT_SCHEMA; }
+ | VARIABLES { $$ = OBJECT_VARIABLE; }
;
@@ -9970,6 +10019,24 @@ RenameStmt: ALTER AGGREGATE aggregate_with_argtypes RENAME TO name
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newname = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newname = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
opt_column: COLUMN
@@ -10331,6 +10398,24 @@ AlterObjectSchemaStmt:
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newschema = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newschema = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
/*****************************************************************************
@@ -10612,6 +10697,14 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec
n->newowner = $6;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name OWNER TO RoleSpec
+ {
+ AlterOwnerStmt *n = makeNode(AlterOwnerStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newowner = $6;
+ $$ = (Node *)n;
+ }
;
@@ -18021,6 +18114,8 @@ unreserved_keyword:
| VALIDATE
| VALIDATOR
| VALUE_P
+ | VARIABLE
+ | VARIABLES
| VARYING
| VERSION_P
| VIEW
@@ -18676,6 +18771,8 @@ bare_label_keyword:
| VALUE_P
| VALUES
| VARCHAR
+ | VARIABLE
+ | VARIABLES
| VARIADIC
| VERBOSE
| VERSION_P
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index abbe1bb45a3..14ed3cd9b3e 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -105,6 +105,7 @@ typedef struct
List *indexes; /* CREATE INDEX items */
List *triggers; /* CREATE TRIGGER items */
List *grants; /* GRANT items */
+ List *variables; /* CREATE VARIABLE items */
} CreateSchemaStmtContext;
@@ -4102,6 +4103,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.indexes = NIL;
cxt.triggers = NIL;
cxt.grants = NIL;
+ cxt.variables = NIL;
/*
* Run through each schema element in the schema element list. Separate
@@ -4170,6 +4172,15 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.grants = lappend(cxt.grants, element);
break;
+ case T_CreateSessionVarStmt:
+ {
+ CreateSessionVarStmt *elp = (CreateSessionVarStmt *) element;
+
+ setSchemaName(cxt.schemaname, &elp->variable->schemaname);
+ cxt.variables = lappend(cxt.variables, element);
+ }
+ break;
+
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(element));
@@ -4183,6 +4194,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
result = list_concat(result, cxt.indexes);
result = list_concat(result, cxt.triggers);
result = list_concat(result, cxt.grants);
+ result = list_concat(result, cxt.variables);
return result;
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 25fe3d58016..99a51877d34 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -23,6 +23,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_inherits.h"
+#include "catalog/pg_variable.h"
#include "catalog/toasting.h"
#include "commands/alter.h"
#include "commands/async.h"
@@ -182,6 +183,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CreateRangeStmt:
case T_CreateRoleStmt:
case T_CreateSchemaStmt:
+ case T_CreateSessionVarStmt:
case T_CreateSeqStmt:
case T_CreateStatsStmt:
case T_CreateStmt:
@@ -1389,6 +1391,10 @@ ProcessUtilitySlow(ParseState *pstate,
}
break;
+ case T_CreateSessionVarStmt:
+ address = CreateVariable(pstate, (CreateSessionVarStmt *) parsetree);
+ break;
+
/*
* ************* object creation / destruction **************
*/
@@ -2341,6 +2347,9 @@ AlterObjectTypeCommandTag(ObjectType objtype)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_ALTER_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_ALTER_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
break;
@@ -2649,6 +2658,9 @@ CreateCommandTag(Node *parsetree)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_DROP_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_DROP_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
@@ -3225,6 +3237,10 @@ CreateCommandTag(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ tag = CMDTAG_CREATE_VARIABLE;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
@@ -3759,6 +3775,10 @@ GetCommandLogLevel(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ lev = LOGSTMT_DDL;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index ba14713fef2..6ce3b937dae 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -31,6 +31,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/proclang.h"
#include "commands/tablespace.h"
@@ -129,6 +130,8 @@ static AclMode convert_type_priv_string(text *priv_type_text);
static AclMode convert_parameter_priv_string(text *priv_text);
static AclMode convert_largeobject_priv_string(text *priv_text);
static AclMode convert_role_priv_string(text *priv_type_text);
+static Oid convert_session_variable_name(text *varname);
+static AclMode convert_session_variable_priv_string(text *priv_type_text);
static AclResult pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode);
static void RoleMembershipCacheCallback(Datum arg, int cacheid, uint32 hashvalue);
@@ -851,6 +854,10 @@ acldefault(ObjectType objtype, Oid ownerId)
world_default = ACL_NO_RIGHTS;
owner_default = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ world_default = ACL_NO_RIGHTS;
+ owner_default = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", (int) objtype);
world_default = ACL_NO_RIGHTS; /* keep compiler quiet */
@@ -948,6 +955,9 @@ acldefault_sql(PG_FUNCTION_ARGS)
case 'T':
objtype = OBJECT_TYPE;
break;
+ case 'V':
+ objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type abbreviation: %c", objtypec);
}
@@ -5016,6 +5026,217 @@ pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode)
return ACLCHECK_NO_PRIV;
}
+/*
+ * has_session_variable_privilege variants
+ * These are all named "has_session_variable_privilege" at the SQL level.
+ * They take various combinations of variable name, variable OID,
+ * user name, user OID, or implicit user = current_user.
+ *
+ * The result is a boolean value: true if user has the indicated
+ * privilege, false if not, or NULL if session variable doesn't
+ * exists.
+ */
+
+/*
+ * has_session_variable_privilege_name_name
+ * Check user privileges on a session variable given
+ * name username, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_name(PG_FUNCTION_ARGS)
+{
+ Name rolename = PG_GETARG_NAME(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*rolename));
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name
+ * Check user privileges on a session variable given
+ * text session variable and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_name(PG_FUNCTION_ARGS)
+{
+ text *varname = PG_GETARG_TEXT_PP(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name_id
+ * Check user privileges on a session variable given
+ * name usename, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_id(PG_FUNCTION_ARGS)
+{
+ Name username = PG_GETARG_NAME(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*username));
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id
+ * Check user privileges on a session variable given
+ * session variable oid, and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_id(PG_FUNCTION_ARGS)
+{
+ Oid varid = PG_GETARG_OID(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_name
+ * Check user privileges on a session variable given
+ * roleid, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_name(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_id
+ * Check user privileges on a session variable given
+ * roleid, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_id(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * Given a session variable name expressed as a string, look it up and return
+ * Oid
+ */
+static Oid
+convert_session_variable_name(text *varname)
+{
+ return LookupVariableFromNameList(textToQualifiedNameList(varname), true);
+}
+
+/*
+ * convert_variable_priv_string
+ * Convert text string to AclMode value.
+ */
+static AclMode
+convert_session_variable_priv_string(text *priv_type_text)
+{
+ static const priv_map session_variable_priv_map[] = {
+ {"SELECT", ACL_SELECT},
+ {"SELECT WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_SELECT)},
+ {"UPDATE", ACL_UPDATE},
+ {"UPDATE WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_UPDATE)},
+ {NULL, 0}
+ };
+
+ return convert_any_priv_string(priv_type_text, session_variable_priv_map);
+}
/*
* initialization function (called by InitPostgres)
diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index 80c5a3fcfb7..cfc0b7e2b70 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -39,6 +39,7 @@
#include "catalog/pg_subscription.h"
#include "catalog/pg_transform.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "utils/array.h"
@@ -3753,3 +3754,115 @@ get_subscription_name(Oid subid, bool missing_ok)
return subname;
}
+
+/* ---------- PG_VARIABLE CACHE ---------- */
+
+/*
+ * get_varname_varid
+ * Given name and namespace of variable, look up the OID.
+ */
+Oid
+get_varname_varid(const char *varname, Oid varnamespace)
+{
+ return GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(varnamespace));
+}
+
+/*
+ * get_session_variable_name
+ * Returns a palloc'd copy of the name of a given session variable.
+ */
+char *
+get_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = pstrdup(NameStr(varform->varname));
+
+ ReleaseSysCache(tup);
+
+ return varname;
+}
+
+/*
+ * get_session_variable_namespace
+ * Returns the pg_namespace OID associated with a given session variable.
+ */
+Oid
+get_session_variable_namespace(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varnamespace = varform->varnamespace;
+
+ ReleaseSysCache(tup);
+
+ return varnamespace;
+}
+
+/*
+ * Returns the type of the given session variable.
+ */
+Oid
+get_session_variable_type(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid vartype;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ vartype = varform->vartype;
+
+ ReleaseSysCache(tup);
+
+ return vartype;
+}
+
+/*
+ * Returns the type, typmod and collid of the given session variable.
+ */
+void
+get_session_variable_type_typmod_collid(Oid varid, Oid *typid, int32 *typmod,
+ Oid *collid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ *typid = varform->vartype;
+ *typmod = varform->vartypmod;
+ *collid = varform->varcollation;
+
+ ReleaseSysCache(tup);
+}
diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c
index 56b6c368acf..ba6b19dc9af 100644
--- a/src/bin/pg_dump/common.c
+++ b/src/bin/pg_dump/common.c
@@ -246,6 +246,9 @@ getSchemaData(Archive *fout, int *numTablesPtr)
pg_log_info("reading subscription membership of tables");
getSubscriptionTables(fout);
+ pg_log_info("reading variables");
+ getVariables(fout);
+
free(inhinfo); /* not needed any longer */
*numTablesPtr = numTables;
diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index 5ae77f76367..5161ee780ea 100644
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -511,6 +511,12 @@ do { \
CONVERT_PRIV('r', "SELECT");
CONVERT_PRIV('w', "UPDATE");
}
+ else if (strcmp(type, "VARIABLE") == 0 ||
+ strcmp(type, "VARIABLES") == 0)
+ {
+ CONVERT_PRIV('r', "SELECT");
+ CONVERT_PRIV('w', "UPDATE");
+ }
else
abort();
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index 658986de6f8..4070543d33b 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -134,12 +134,14 @@ typedef struct _restoreOptions
int selFunction;
int selTrigger;
int selTable;
+ int selVariable;
SimpleStringList indexNames;
SimpleStringList functionNames;
SimpleStringList schemaNames;
SimpleStringList schemaExcludeNames;
SimpleStringList triggerNames;
SimpleStringList tableNames;
+ SimpleStringList variableNames;
int useDB;
ConnParams cparams; /* parameters to use if useDB */
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 82d51c89ac6..1e966d224a3 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -3132,6 +3132,14 @@ _tocEntryRequired(TocEntry *te, teSection curSection, ArchiveHandle *AH)
!simple_string_list_member(&ropt->triggerNames, te->tag))
return 0;
}
+ else if (strcmp(te->desc, "VARIABLE") == 0)
+ {
+ if (!ropt->selVariable)
+ return 0;
+ if (ropt->variableNames.head != NULL &&
+ !simple_string_list_member(&ropt->variableNames, te->tag))
+ return 0;
+ }
else
return 0;
}
@@ -3682,6 +3690,7 @@ _getObjectDescription(PQExpBuffer buf, const TocEntry *te)
strcmp(type, "TEXT SEARCH DICTIONARY") == 0 ||
strcmp(type, "TEXT SEARCH CONFIGURATION") == 0 ||
strcmp(type, "TYPE") == 0 ||
+ strcmp(type, "VARIABLE") == 0 ||
strcmp(type, "VIEW") == 0 ||
/* non-schema-specified objects */
strcmp(type, "DATABASE") == 0 ||
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 428ed2d60fc..59ccabe4507 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -365,6 +365,7 @@ static void dumpPublication(Archive *fout, const PublicationInfo *pubinfo);
static void dumpPublicationTable(Archive *fout, const PublicationRelInfo *pubrinfo);
static void dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo);
static void dumpSubscriptionTable(Archive *fout, const SubRelInfo *subrinfo);
+static void dumpVariable(Archive *fout, const VariableInfo *varinfo);
static void dumpDatabase(Archive *fout);
static void dumpDatabaseConfig(Archive *AH, PQExpBuffer outbuf,
const char *dbname, Oid dboid);
@@ -5459,6 +5460,188 @@ get_next_possible_free_pg_type_oid(Archive *fout, PQExpBuffer upgrade_query)
return next_possible_free_oid;
}
+/*
+ * getVariables
+ * get information about variables
+ */
+void
+getVariables(Archive *fout)
+{
+ PQExpBuffer query;
+ PGresult *res;
+ VariableInfo *varinfo;
+ int i_tableoid;
+ int i_oid;
+ int i_varname;
+ int i_varnamespace;
+ int i_vartype;
+ int i_vartypname;
+ int i_varowner;
+ int i_varcollation;
+ int i_varacl;
+ int i_acldefault;
+ int i,
+ ntups;
+
+ if (fout->remoteVersion < 180000)
+ return;
+
+ query = createPQExpBuffer();
+
+ /* get the variables in current database */
+ appendPQExpBuffer(query,
+ "SELECT v.tableoid, v.oid, v.varname,\n"
+ " v.varnamespace, v.vartype,\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n"
+ " CASE WHEN v.varcollation <> t.typcollation "
+ " THEN v.varcollation\n"
+ " ELSE 0\n"
+ " END AS varcollation,\n"
+ " v.varowner, v.varacl,\n"
+ " acldefault('V', v.varowner) AS acldefault\n"
+ "FROM pg_catalog.pg_variable v\n"
+ "JOIN pg_catalog.pg_type t "
+ "ON (v.vartype = t.oid)");
+
+ res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK);
+
+ ntups = PQntuples(res);
+
+ i_tableoid = PQfnumber(res, "tableoid");
+ i_oid = PQfnumber(res, "oid");
+ i_varname = PQfnumber(res, "varname");
+ i_varnamespace = PQfnumber(res, "varnamespace");
+ i_vartype = PQfnumber(res, "vartype");
+ i_vartypname = PQfnumber(res, "vartypname");
+ i_varcollation = PQfnumber(res, "varcollation");
+
+ i_varowner = PQfnumber(res, "varowner");
+ i_varacl = PQfnumber(res, "varacl");
+ i_acldefault = PQfnumber(res, "acldefault");
+
+ varinfo = pg_malloc(ntups * sizeof(VariableInfo));
+
+ for (i = 0; i < ntups; i++)
+ {
+ TypeInfo *vtype;
+
+ varinfo[i].dobj.objType = DO_VARIABLE;
+ varinfo[i].dobj.catId.tableoid =
+ atooid(PQgetvalue(res, i, i_tableoid));
+ varinfo[i].dobj.catId.oid = atooid(PQgetvalue(res, i, i_oid));
+ AssignDumpId(&varinfo[i].dobj);
+ varinfo[i].dobj.name = pg_strdup(PQgetvalue(res, i, i_varname));
+ varinfo[i].dobj.namespace =
+ findNamespace(atooid(PQgetvalue(res, i, i_varnamespace)));
+
+ varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype));
+ varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname));
+ varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
+
+ varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
+ varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
+ varinfo[i].dacl.privtype = 0;
+ varinfo[i].dacl.initprivs = NULL;
+ varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner));
+
+ /* do not try to dump ACL if no ACL exists */
+ if (!PQgetisnull(res, i, i_varacl))
+ varinfo[i].dobj.components |= DUMP_COMPONENT_ACL;
+
+ if (strlen(varinfo[i].rolname) == 0)
+ pg_log_warning("owner of variable \"%s\" appears to be invalid",
+ varinfo[i].dobj.name);
+
+ /* decide whether we want to dump it */
+ selectDumpableObject(&(varinfo[i].dobj), fout);
+
+ vtype = findTypeByOid(varinfo[i].vartype);
+ addObjectDependency(&varinfo[i].dobj, vtype->dobj.dumpId);
+ }
+ PQclear(res);
+
+ destroyPQExpBuffer(query);
+}
+
+/*
+ * dumpVariable
+ * dump the definition of the given session variable
+ */
+static void
+dumpVariable(Archive *fout, const VariableInfo *varinfo)
+{
+ DumpOptions *dopt = fout->dopt;
+
+ PQExpBuffer delq;
+ PQExpBuffer query;
+ char *qualvarname;
+ const char *vartypname;
+ Oid varcollation;
+
+ /* skip if not to be dumped */
+ if (!varinfo->dobj.dump || !dopt->dumpSchema)
+ return;
+
+ delq = createPQExpBuffer();
+ query = createPQExpBuffer();
+
+ qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
+ vartypname = varinfo->vartypname;
+ varcollation = varinfo->varcollation;
+
+ appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
+ qualvarname);
+
+ appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s",
+ qualvarname, vartypname);
+
+ if (OidIsValid(varcollation))
+ {
+ CollInfo *coll;
+
+ coll = findCollationByOid(varcollation);
+ if (coll)
+ appendPQExpBuffer(query, " COLLATE %s",
+ fmtQualifiedDumpable(coll));
+ }
+
+ appendPQExpBuffer(query, ";\n");
+
+ if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
+ ArchiveEntry(fout, varinfo->dobj.catId, varinfo->dobj.dumpId,
+ ARCHIVE_OPTS(.tag = varinfo->dobj.name,
+ .namespace = varinfo->dobj.namespace->dobj.name,
+ .owner = varinfo->rolname,
+ .description = "VARIABLE",
+ .section = SECTION_PRE_DATA,
+ .createStmt = query->data,
+ .dropStmt = delq->data));
+
+ /* dump comment if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_COMMENT)
+ dumpComment(fout, "VARIABLE", qualvarname,
+ NULL, varinfo->rolname,
+ varinfo->dobj.catId, 0, varinfo->dobj.dumpId);
+
+ /* dump ACL if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_ACL)
+ {
+ char *qvarname = pg_strdup(fmtId(varinfo->dobj.name));
+
+ dumpACL(fout, varinfo->dobj.dumpId, InvalidDumpId, "VARIABLE",
+ qvarname, NULL,
+ varinfo->dobj.namespace->dobj.name, NULL, varinfo->rolname,
+ &varinfo->dacl);
+
+ free(qvarname);
+ }
+
+ destroyPQExpBuffer(delq);
+ destroyPQExpBuffer(query);
+
+ free(qualvarname);
+}
+
static void
binary_upgrade_set_type_oids_by_type_oid(Archive *fout,
PQExpBuffer upgrade_buffer,
@@ -11160,6 +11343,9 @@ dumpDumpableObject(Archive *fout, DumpableObject *dobj)
case DO_REL_STATS:
dumpRelationStats(fout, (const RelStatsInfo *) dobj);
break;
+ case DO_VARIABLE:
+ dumpVariable(fout, (VariableInfo *) dobj);
+ break;
case DO_PRE_DATA_BOUNDARY:
case DO_POST_DATA_BOUNDARY:
/* never dumped, nothing to do */
@@ -15611,6 +15797,9 @@ dumpDefaultACL(Archive *fout, const DefaultACLInfo *daclinfo)
case DEFACLOBJ_NAMESPACE:
type = "SCHEMAS";
break;
+ case DEFACLOBJ_VARIABLE:
+ type = "VARIABLES";
+ break;
default:
/* shouldn't get here */
pg_fatal("unrecognized object type in default privileges: %d",
@@ -19333,6 +19522,7 @@ addBoundaryDependencies(DumpableObject **dobjs, int numObjs,
case DO_CONVERSION:
case DO_TABLE:
case DO_TABLE_ATTACH:
+ case DO_VARIABLE:
case DO_ATTRDEF:
case DO_PROCLANG:
case DO_CAST:
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index bbdb30b5f54..cd8d9880b35 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -53,6 +53,7 @@ typedef enum
DO_TABLE,
DO_TABLE_ATTACH,
DO_ATTRDEF,
+ DO_VARIABLE,
DO_INDEX,
DO_INDEX_ATTACH,
DO_STATSEXT,
@@ -730,6 +731,19 @@ typedef struct _SubRelInfo
char *srsublsn;
} SubRelInfo;
+/*
+ * The VariableInfo struct is used to represent session variables
+ */
+typedef struct _VariableInfo
+{
+ DumpableObject dobj;
+ DumpableAcl dacl;
+ Oid vartype;
+ char *vartypname;
+ Oid varcollation;
+ const char *rolname; /* name of owner, or empty string */
+} VariableInfo;
+
/*
* common utility functions
*/
@@ -813,5 +827,6 @@ extern void getPublicationTables(Archive *fout, TableInfo tblinfo[],
int numTables);
extern void getSubscriptions(Archive *fout);
extern void getSubscriptionTables(Archive *fout);
+extern void getVariables(Archive *fout);
#endif /* PG_DUMP_H */
diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c
index f75e9928bad..b4c2d07a02e 100644
--- a/src/bin/pg_dump/pg_dump_sort.c
+++ b/src/bin/pg_dump/pg_dump_sort.c
@@ -77,6 +77,7 @@ enum dbObjectTypePriorities
PRIO_DUMMY_TYPE,
PRIO_ATTRDEF,
PRIO_LARGE_OBJECT,
+ PRIO_VARIABLE,
PRIO_PRE_DATA_BOUNDARY, /* boundary! */
PRIO_TABLE_DATA,
PRIO_SEQUENCE_SET,
@@ -119,6 +120,7 @@ static const int dbObjectTypePriority[] =
[DO_TABLE] = PRIO_TABLE,
[DO_TABLE_ATTACH] = PRIO_TABLE_ATTACH,
[DO_ATTRDEF] = PRIO_ATTRDEF,
+ [DO_VARIABLE] = PRIO_VARIABLE,
[DO_INDEX] = PRIO_INDEX,
[DO_INDEX_ATTACH] = PRIO_INDEX_ATTACH,
[DO_STATSEXT] = PRIO_STATSEXT,
@@ -1533,6 +1535,11 @@ describeDumpableObject(DumpableObject *obj, char *buf, int bufsize)
"RELATION STATISTICS FOR %s (ID %d OID %u)",
obj->name, obj->dumpId, obj->catId.oid);
return;
+ case DO_VARIABLE:
+ snprintf(buf, bufsize,
+ "VARIABLE %s (ID %d OID %u)",
+ obj->name, obj->dumpId, obj->catId.oid);
+ return;
}
/* shouldn't get here */
snprintf(buf, bufsize,
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index d281e27aa67..725a7f27235 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -892,6 +892,16 @@ my %tests = (
unlike => { no_privs => 1, },
},
+ 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC'
+ => {
+ create_order => 56,
+ create_sql => 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;',
+ regexp => qr/^
+ \QALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;\E/xm,
+ like => { %full_runs, section_post_data => 1, },
+ unlike => { no_privs => 1, },
+ },
+
'ALTER ROLE regress_dump_test_role' => {
regexp => qr/^
\QALTER ROLE regress_dump_test_role WITH \E
@@ -1783,6 +1793,23 @@ my %tests = (
},
},
+ 'COMMENT ON VARIABLE dump_test.variable1' => {
+ create_order => 71,
+ create_sql => 'COMMENT ON VARIABLE dump_test.variable1
+ IS \'comment on variable\';',
+ regexp =>
+ qr/^\QCOMMENT ON VARIABLE dump_test.variable1 IS 'comment on variable';\E/m,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'COPY test_table' => {
create_order => 4,
create_sql => 'INSERT INTO dump_test.test_table (col1) '
@@ -4082,6 +4109,24 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable1 AS integer;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable1 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
@@ -4545,6 +4590,25 @@ my %tests = (
like => {},
},
+ 'GRANT SELECT ON VARIABLE dump_test.variable1' => {
+ create_order => 73,
+ create_sql =>
+ 'GRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;',
+ regexp => qr/^
+ \QGRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;\E
+ /xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ no_privs => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'REFRESH MATERIALIZED VIEW matview' => {
regexp => qr/^\QREFRESH MATERIALIZED VIEW dump_test.matview;\E/m,
like =>
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index fb0b27568c5..9625952aaea 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -1243,6 +1243,9 @@ exec_command_d(PsqlScanState scan_state, bool active_branch, const char *cmd)
break;
}
break;
+ case 'V': /* Variables */
+ success = listVariables(pattern, show_verbose);
+ break;
case 'x': /* Extensions */
if (show_verbose)
success = listExtensionContents(pattern);
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..783cbb9cd11 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -1222,7 +1222,7 @@ listDefaultACLs(const char *pattern)
printfPQExpBuffer(&buf,
"SELECT pg_catalog.pg_get_userbyid(d.defaclrole) AS \"%s\",\n"
" n.nspname AS \"%s\",\n"
- " CASE d.defaclobjtype WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
+ " CASE d.defaclobjtype WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
" ",
gettext_noop("Owner"),
gettext_noop("Schema"),
@@ -1236,6 +1236,8 @@ listDefaultACLs(const char *pattern)
gettext_noop("type"),
DEFACLOBJ_NAMESPACE,
gettext_noop("schema"),
+ DEFACLOBJ_VARIABLE,
+ gettext_noop("session variable"),
gettext_noop("Type"));
printACLColumn(&buf, "d.defaclacl");
@@ -5318,6 +5320,102 @@ error_return:
return false;
}
+/*
+ * \dV
+ *
+ * listVariables()
+ */
+bool
+listVariables(const char *pattern, bool verbose)
+{
+ PQExpBufferData buf;
+ PGresult *res;
+ printQueryOpt myopt = pset.popt;
+ static const bool translate_columns[] = {false, false, false, false, false, false, false};
+
+ if (pset.sversion < 180000)
+ {
+ char sverbuf[32];
+
+ pg_log_error("The server (version %s) does not support session variables.",
+ formatPGVersionNumber(pset.sversion, false,
+ sverbuf, sizeof(sverbuf)));
+ return true;
+ }
+
+ initPQExpBuffer(&buf);
+
+ printfPQExpBuffer(&buf,
+ "SELECT n.nspname as \"%s\",\n"
+ " v.varname as \"%s\",\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n"
+ " (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
+ " WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
+ " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n",
+ gettext_noop("Schema"),
+ gettext_noop("Name"),
+ gettext_noop("Type"),
+ gettext_noop("Collation"),
+ gettext_noop("Owner"));
+
+ if (verbose)
+ {
+ appendPQExpBufferStr(&buf, ",\n ");
+ printACLColumn(&buf, "v.varacl");
+ appendPQExpBuffer(&buf,
+ ",\n pg_catalog.obj_description(v.oid, 'pg_variable') AS \"%s\"",
+ gettext_noop("Description"));
+ }
+
+ appendPQExpBufferStr(&buf,
+ "\nFROM pg_catalog.pg_variable v"
+ "\n LEFT JOIN pg_catalog.pg_namespace n ON n.oid = v.varnamespace");
+
+ appendPQExpBufferStr(&buf, "\nWHERE true\n");
+ if (!pattern)
+ appendPQExpBufferStr(&buf, " AND n.nspname <> 'pg_catalog'\n"
+ " AND n.nspname <> 'information_schema'\n");
+
+ if (!validateSQLNamePattern(&buf, pattern, true, false,
+ "n.nspname", "v.varname", NULL,
+ "pg_catalog.pg_variable_is_visible(v.oid)",
+ NULL, 3))
+ return false;
+
+ appendPQExpBufferStr(&buf, "ORDER BY 1,2;");
+
+ res = PSQLexec(buf.data);
+ termPQExpBuffer(&buf);
+ if (!res)
+ return false;
+
+ /*
+ * Most functions in this file are content to print an empty table when
+ * there are no matching objects. We intentionally deviate from that
+ * here, but only in !quiet mode, for historical reasons.
+ */
+ if (PQntuples(res) == 0 && !pset.quiet)
+ {
+ if (pattern)
+ pg_log_error("Did not find any session variable named \"%s\".",
+ pattern);
+ else
+ pg_log_error("Did not find any session variables.");
+ }
+ else
+ {
+ myopt.nullPrint = NULL;
+ myopt.title = _("List of variables");
+ myopt.translate_header = true;
+ myopt.translate_columns = translate_columns;
+ myopt.n_translate_columns = lengthof(translate_columns);
+
+ printQuery(res, &myopt, pset.queryFout, false, pset.logfile);
+ }
+
+ PQclear(res);
+ return true;
+}
/*
* \dFp
diff --git a/src/bin/psql/describe.h b/src/bin/psql/describe.h
index 18ecaa60949..55ced4aab7b 100644
--- a/src/bin/psql/describe.h
+++ b/src/bin/psql/describe.h
@@ -149,4 +149,7 @@ extern bool listOpFamilyFunctions(const char *access_method_pattern,
/* \dl or \lo_list */
extern bool listLargeObjects(bool verbose);
+/* \dV */
+extern bool listVariables(const char *pattern, bool varbose);
+
#endif /* DESCRIBE_H */
diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index 714b8619233..ee659d6055b 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -273,6 +273,7 @@ slashUsage(unsigned short int pager)
HELP0(" \\dT[Sx+] [PATTERN] list data types\n");
HELP0(" \\du[Sx+] [PATTERN] list roles\n");
HELP0(" \\dv[Sx+] [PATTERN] list views\n");
+ HELP0(" \\dV[x+] [PATTERN] list session variables\n");
HELP0(" \\dx[x+] [PATTERN] list extensions\n");
HELP0(" \\dX[x] [PATTERN] list extended statistics\n");
HELP0(" \\dy[x+] [PATTERN] list event triggers\n");
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 8432be641ac..84907f76c0a 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -970,6 +970,13 @@ static const SchemaQuery Query_for_trigger_of_table = {
.refnamespace = "c1.relnamespace",
};
+static const SchemaQuery Query_for_list_of_variables = {
+ .min_server_version = 180000,
+ .catname = "pg_catalog.pg_variable v",
+ .viscondition = "pg_catalog.pg_variable_is_visible(v.oid)",
+ .namespace = "v.varnamespace",
+ .result = "v.varname",
+};
/*
* Queries to get lists of names of various kinds of things, possibly
@@ -1318,6 +1325,7 @@ static const pgsql_thing_t words_after_create[] = {
* TABLE ... */
{"USER", Query_for_list_of_roles, NULL, NULL, Keywords_for_user_thing},
{"USER MAPPING FOR", NULL, NULL, NULL},
+ {"VARIABLE", NULL, NULL, &Query_for_list_of_variables},
{"VIEW", NULL, NULL, &Query_for_list_of_views},
{NULL} /* end of list */
};
@@ -1883,7 +1891,7 @@ psql_completion(const char *text, int start, int end)
"\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL",
"\\dm", "\\dn", "\\do", "\\dO", "\\dp", "\\dP", "\\dPi", "\\dPt",
"\\drds", "\\drg", "\\dRs", "\\dRp", "\\ds",
- "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy",
+ "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy", "\\dV",
"\\echo", "\\edit", "\\ef", "\\elif", "\\else", "\\encoding",
"\\endif", "\\endpipeline", "\\errverbose", "\\ev",
"\\f", "\\flush", "\\flushrequest",
@@ -2585,6 +2593,9 @@ match_previous_words(int pattern_id,
"ALL");
else if (Matches("ALTER", "SYSTEM", "SET", MatchAny))
COMPLETE_WITH("TO");
+ /* ALTER VARIABLE <name> */
+ else if (Matches("ALTER", "VARIABLE", MatchAny))
+ COMPLETE_WITH("OWNER TO", "RENAME TO", "SET SCHEMA");
/* ALTER VIEW <name> */
else if (Matches("ALTER", "VIEW", MatchAny))
COMPLETE_WITH("ALTER COLUMN", "OWNER TO", "RENAME", "RESET", "SET");
@@ -3165,7 +3176,7 @@ match_previous_words(int pattern_id,
"ROUTINE", "RULE", "SCHEMA", "SEQUENCE", "SERVER",
"STATISTICS", "SUBSCRIPTION", "TABLE",
"TABLESPACE", "TEXT SEARCH", "TRANSFORM FOR",
- "TRIGGER", "TYPE", "VIEW");
+ "TRIGGER", "TYPE", "VARIABLE", "VIEW");
else if (Matches("COMMENT", "ON", "ACCESS", "METHOD"))
COMPLETE_WITH_QUERY(Query_for_list_of_access_methods);
else if (Matches("COMMENT", "ON", "CONSTRAINT"))
@@ -3975,6 +3986,13 @@ match_previous_words(int pattern_id,
else if (TailMatches("=", MatchAnyExcept("*)")))
COMPLETE_WITH(",", ")");
}
+/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
+ /* Complete CREATE VARIABLE <name> with AS */
+ else if (TailMatches("CREATE", "VARIABLE", MatchAny))
+ COMPLETE_WITH("AS");
+ else if (TailMatches("VARIABLE", MatchAny, "AS"))
+ /* Complete CREATE VARIABLE <name> with AS types */
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
/* CREATE VIEW --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE [ OR REPLACE ] VIEW <name> with AS or WITH */
@@ -4252,6 +4270,12 @@ match_previous_words(int pattern_id,
else if (Matches("DROP", "TRANSFORM", "FOR", MatchAny, "LANGUAGE", MatchAny))
COMPLETE_WITH("CASCADE", "RESTRICT");
+ /* DROP VARIABLE */
+ else if (Matches("DROP", "VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ else if (Matches("DROP", "VARIABLE", MatchAny))
+ COMPLETE_WITH("CASCADE", "RESTRICT");
+
/* EXECUTE */
else if (Matches("EXECUTE"))
COMPLETE_WITH_QUERY(Query_for_list_of_prepared_statements);
@@ -4453,7 +4477,7 @@ match_previous_words(int pattern_id,
* objects supported.
*/
if (HeadMatches("ALTER", "DEFAULT", "PRIVILEGES"))
- COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS");
+ COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS", "VARIABLES");
else
COMPLETE_WITH_SCHEMA_QUERY_PLUS(Query_for_list_of_grantables,
"ALL FUNCTIONS IN SCHEMA",
@@ -4461,6 +4485,7 @@ match_previous_words(int pattern_id,
"ALL ROUTINES IN SCHEMA",
"ALL SEQUENCES IN SCHEMA",
"ALL TABLES IN SCHEMA",
+ "ALL VARIABLES IN SCHEMA",
"DATABASE",
"DOMAIN",
"FOREIGN DATA WRAPPER",
@@ -4475,7 +4500,8 @@ match_previous_words(int pattern_id,
"SEQUENCE",
"TABLE",
"TABLESPACE",
- "TYPE");
+ "TYPE",
+ "VARIABLE");
}
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "ALL") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "ALL"))
@@ -4483,7 +4509,8 @@ match_previous_words(int pattern_id,
"PROCEDURES IN SCHEMA",
"ROUTINES IN SCHEMA",
"SEQUENCES IN SCHEMA",
- "TABLES IN SCHEMA");
+ "TABLES IN SCHEMA",
+ "VARIABLES IN SCHEMA");
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "FOREIGN") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "FOREIGN"))
COMPLETE_WITH("DATA WRAPPER", "SERVER");
@@ -4519,6 +4546,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_tablespaces);
else if (TailMatches("TYPE"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
+ else if (TailMatches("VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatches("GRANT", MatchAny, MatchAny, MatchAny))
COMPLETE_WITH("TO");
else
@@ -4821,7 +4850,7 @@ match_previous_words(int pattern_id,
/* PREPARE xx AS */
else if (Matches("PREPARE", MatchAny, "AS"))
- COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM");
+ COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM", "LET");
/*
* PREPARE TRANSACTION is missing on purpose. It's intended for transaction
@@ -5305,6 +5334,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_roles);
else if (TailMatchesCS("\\dv*"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_views);
+ else if (TailMatchesCS("\\dV*"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatchesCS("\\dx*"))
COMPLETE_WITH_QUERY(Query_for_list_of_extensions);
else if (TailMatchesCS("\\dX*"))
diff --git a/src/include/catalog/Makefile b/src/include/catalog/Makefile
index 2bbc7805fe3..f98760de635 100644
--- a/src/include/catalog/Makefile
+++ b/src/include/catalog/Makefile
@@ -81,7 +81,8 @@ CATALOG_HEADERS := \
pg_publication_namespace.h \
pg_publication_rel.h \
pg_subscription.h \
- pg_subscription_rel.h
+ pg_subscription_rel.h \
+ pg_variable.h
GENERATED_HEADERS := $(CATALOG_HEADERS:%.h=%_d.h)
diff --git a/src/include/catalog/meson.build b/src/include/catalog/meson.build
index ec1cf467f6f..81398efa7c9 100644
--- a/src/include/catalog/meson.build
+++ b/src/include/catalog/meson.build
@@ -69,6 +69,7 @@ catalog_headers = [
'pg_publication_rel.h',
'pg_subscription.h',
'pg_subscription_rel.h',
+ 'pg_variable.h',
]
# The .dat files we need can just be listed alphabetically.
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index 8c7ccc69a3c..bdac0c13bec 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -97,6 +97,8 @@ extern Oid TypenameGetTypid(const char *typname);
extern Oid TypenameGetTypidExtended(const char *typname, bool temp_ok);
extern bool TypeIsVisible(Oid typid);
+extern bool VariableIsVisible(Oid varid);
+
extern FuncCandidateList FuncnameGetCandidates(List *names,
int nargs, List *argnames,
bool expand_variadic,
@@ -169,6 +171,10 @@ extern SearchPathMatcher *GetSearchPathMatcher(MemoryContext context);
extern SearchPathMatcher *CopySearchPathMatcher(SearchPathMatcher *path);
extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
+extern List *NamesFromList(List *names);
+extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
+extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
extern Oid FindDefaultConversionProc(int32 for_encoding, int32 to_encoding);
diff --git a/src/include/catalog/pg_default_acl.h b/src/include/catalog/pg_default_acl.h
index 728024b1fa7..5f94424a684 100644
--- a/src/include/catalog/pg_default_acl.h
+++ b/src/include/catalog/pg_default_acl.h
@@ -68,6 +68,7 @@ MAKE_SYSCACHE(DEFACLROLENSPOBJ, pg_default_acl_role_nsp_obj_index, 8);
#define DEFACLOBJ_FUNCTION 'f' /* function */
#define DEFACLOBJ_TYPE 'T' /* type */
#define DEFACLOBJ_NAMESPACE 'n' /* namespace */
+#define DEFACLOBJ_VARIABLE 'V' /* variable */
#endif /* EXPOSE_TO_CLIENT_CODE */
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 890822eaf79..2d89008e60f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5426,6 +5426,26 @@
prorettype => 'bool', proargtypes => 'oid oid text',
prosrc => 'has_largeobject_privilege_id_id' },
+{ oid => '9613', descr => 'user privilege on session variable by username, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name text text',
+ prosrc => 'has_session_variable_privilege_name_name' },
+{ oid => '9614', descr => 'user privilege on session variable by username, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name oid text', prosrc => 'has_session_variable_privilege_name_id' },
+{ oid => '9615', descr => 'user privilege on session variable by user oid, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text text', prosrc => 'has_session_variable_privilege_id_name' },
+{ oid => '9616', descr => 'user privilege on session variable by user oid, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid oid text', prosrc => 'has_session_variable_privilege_id_id' },
+{ oid => '9617', descr => 'current user privilege on session variable by seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'text text', prosrc => 'has_session_variable_privilege_name' },
+{ oid => '9618', descr => 'current user privilege on session variable by seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text', prosrc => 'has_session_variable_privilege_id' },
+
{ oid => '3355', descr => 'I/O',
proname => 'pg_ndistinct_in', prorettype => 'pg_ndistinct',
proargtypes => 'cstring', prosrc => 'pg_ndistinct_in' },
@@ -6633,6 +6653,9 @@
proname => 'pg_collation_is_visible', procost => '10', provolatile => 's',
prorettype => 'bool', proargtypes => 'oid',
prosrc => 'pg_collation_is_visible' },
+{ oid => '9999', descr => 'is session variable visible in search path?',
+ proname => 'pg_variable_is_visible', procost => '10', provolatile => 's',
+ prorettype => 'bool', proargtypes => 'oid', prosrc => 'pg_variable_is_visible' },
{ oid => '2854', descr => 'get OID of current session\'s temp schema, if any',
proname => 'pg_my_temp_schema', provolatile => 's', proparallel => 'r',
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
new file mode 100644
index 00000000000..3d3c6eb24b5
--- /dev/null
+++ b/src/include/catalog/pg_variable.h
@@ -0,0 +1,81 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.h
+ * definition of session variables system catalog (pg_variables)
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/catalog/pg_variable.h
+ *
+ * NOTES
+ * The Catalog.pm module reads this file and derives schema
+ * information.
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_VARIABLE_H
+#define PG_VARIABLE_H
+
+#include "catalog/genbki.h"
+#include "catalog/objectaddress.h"
+#include "catalog/pg_variable_d.h"
+#include "utils/acl.h"
+
+/* ----------------
+ * pg_variable definition. cpp turns this into
+ * typedef struct FormData_pg_variable
+ * ----------------
+ */
+CATALOG(pg_variable,9222,VariableRelationId)
+{
+ Oid oid; /* oid */
+
+ /* OID of entry in pg_type for variable's type */
+ Oid vartype BKI_LOOKUP(pg_type);
+
+ /* variable name */
+ NameData varname;
+
+ /* OID of namespace containing variable class */
+ Oid varnamespace BKI_LOOKUP(pg_namespace);
+
+ /* variable owner */
+ Oid varowner BKI_LOOKUP(pg_authid);
+
+ /* typmod for variable's type */
+ int32 vartypmod BKI_DEFAULT(-1);
+
+ /* variable collation */
+ Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation);
+
+
+#ifdef CATALOG_VARLEN /* variable-length fields start here */
+
+ /* access permissions */
+ aclitem varacl[1] BKI_DEFAULT(_null_);
+
+#endif
+} FormData_pg_variable;
+
+/* ----------------
+ * Form_pg_variable corresponds to a pointer to a tuple with
+ * the format of the pg_variable relation.
+ * ----------------
+ */
+typedef FormData_pg_variable *Form_pg_variable;
+
+DECLARE_TOAST(pg_variable, 9223, 9224);
+
+DECLARE_UNIQUE_INDEX_PKEY(pg_variable_oid_index, 9225, VariableOidIndexId, pg_variable, btree(oid oid_ops));
+DECLARE_UNIQUE_INDEX(pg_variable_varname_nsp_index, 9226, VariableNameNspIndexId, pg_variable, btree(varname name_ops, varnamespace oid_ops));
+
+extern ObjectAddress CreateVariable(ParseState *pstate,
+ CreateSessionVarStmt *stmt);
+extern void DropVariableById(Oid varid);
+
+MAKE_SYSCACHE(VARIABLENAMENSP, pg_variable_varname_nsp_index, 8);
+MAKE_SYSCACHE(VARIABLEOID, pg_variable_oid_index, 8);
+
+#endif /* PG_VARIABLE_H */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 23c9e3c5abf..09adbd490cc 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2360,6 +2360,7 @@ typedef enum ObjectType
OBJECT_TSTEMPLATE,
OBJECT_TYPE,
OBJECT_USER_MAPPING,
+ OBJECT_VARIABLE,
OBJECT_VIEW,
} ObjectType;
@@ -3508,6 +3509,21 @@ typedef struct AlterStatsStmt
bool missing_ok; /* skip error if statistics object is missing */
} AlterStatsStmt;
+
+/* ----------------------
+ * {Create|Alter} VARIABLE Statement
+ * ----------------------
+ */
+typedef struct CreateSessionVarStmt
+{
+ NodeTag type;
+ RangeVar *variable; /* the variable to create */
+ TypeName *typeName; /* the type of variable */
+ CollateClause *collClause;
+ bool if_not_exists; /* do nothing if it already exists */
+} CreateSessionVarStmt;
+
+
/* ----------------------
* Create Function Statement
* ----------------------
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 40cf090ce61..793ace526df 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -485,6 +485,8 @@ PG_KEYWORD("validator", VALIDATOR, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("value", VALUE_P, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("values", VALUES, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("varchar", VARCHAR, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variable", VARIABLE, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variables", VARIABLES, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("variadic", VARIADIC, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("varying", VARYING, UNRESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("verbose", VERBOSE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index d250a714d59..ea86954dded 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -68,6 +68,7 @@ PG_CMDTAG(CMDTAG_ALTER_TRANSFORM, "ALTER TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TRIGGER, "ALTER TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TYPE, "ALTER TYPE", true, true, false)
PG_CMDTAG(CMDTAG_ALTER_USER_MAPPING, "ALTER USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_ALTER_VARIABLE, "ALTER VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_VIEW, "ALTER VIEW", true, false, false)
PG_CMDTAG(CMDTAG_ANALYZE, "ANALYZE", false, false, false)
PG_CMDTAG(CMDTAG_BEGIN, "BEGIN", false, false, false)
@@ -123,6 +124,7 @@ PG_CMDTAG(CMDTAG_CREATE_TRANSFORM, "CREATE TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TRIGGER, "CREATE TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TYPE, "CREATE TYPE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_USER_MAPPING, "CREATE USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_CREATE_VARIABLE, "CREATE VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_VIEW, "CREATE VIEW", true, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE, "DEALLOCATE", false, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE_ALL, "DEALLOCATE ALL", false, false, false)
@@ -175,6 +177,7 @@ PG_CMDTAG(CMDTAG_DROP_TRANSFORM, "DROP TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TRIGGER, "DROP TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TYPE, "DROP TYPE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_USER_MAPPING, "DROP USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_DROP_VARIABLE, "DROP VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_VIEW, "DROP VIEW", true, false, false)
PG_CMDTAG(CMDTAG_EXECUTE, "EXECUTE", false, false, false)
PG_CMDTAG(CMDTAG_EXPLAIN, "EXPLAIN", false, false, false)
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index 01ae5b719fd..5e1a8a82e90 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -169,6 +169,7 @@ typedef struct ArrayType Acl;
#define ACL_ALL_RIGHTS_SCHEMA (ACL_USAGE|ACL_CREATE)
#define ACL_ALL_RIGHTS_TABLESPACE (ACL_CREATE)
#define ACL_ALL_RIGHTS_TYPE (ACL_USAGE)
+#define ACL_ALL_RIGHTS_VARIABLE (ACL_SELECT|ACL_UPDATE)
/* operation codes for pg_*_aclmask */
typedef enum
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 6fab7aa6009..9503b528647 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -135,6 +135,7 @@ extern char get_func_prokind(Oid funcid);
extern bool get_func_leakproof(Oid funcid);
extern RegProcedure get_func_support(Oid funcid);
extern Oid get_relname_relid(const char *relname, Oid relnamespace);
+extern Oid get_varname_varid(const char *varname, Oid varnamespace);
extern char *get_rel_name(Oid relid);
extern Oid get_rel_namespace(Oid relid);
extern Oid get_rel_type_id(Oid relid);
@@ -207,6 +208,14 @@ extern char *get_publication_name(Oid pubid, bool missing_ok);
extern Oid get_subscription_oid(const char *subname, bool missing_ok);
extern char *get_subscription_name(Oid subid, bool missing_ok);
+extern char *get_session_variable_name(Oid varid);
+extern Oid get_session_variable_namespace(Oid varid);
+extern Oid get_session_variable_type(Oid varid);
+extern void get_session_variable_type_typmod_collid(Oid varid,
+ Oid *typid,
+ int32 *typmod,
+ Oid *collid);
+
#define type_is_array(typid) (get_element_type(typid) != InvalidOid)
/* type_is_array_domain accepts both plain arrays and domains over arrays */
#define type_is_array_domain(typid) (get_base_element_type(typid) != InvalidOid)
diff --git a/src/test/regress/expected/dependency.out b/src/test/regress/expected/dependency.out
index 75a078ada9e..cd8e4412fa9 100644
--- a/src/test/regress/expected/dependency.out
+++ b/src/test/regress/expected/dependency.out
@@ -151,3 +151,20 @@ owner of type deptest_t
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+-- should fail
+DROP DOMAIN vardomain;
+ERROR: cannot drop type vardomain because other objects depend on it
+DETAIL: column c of composite type vartype depends on type vardomain
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP TYPE vartype;
+ERROR: cannot drop type vartype because other objects depend on it
+DETAIL: session variable var1 depends on type vartype
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/expected/oidjoins.out b/src/test/regress/expected/oidjoins.out
index 215eb899be3..d9953321402 100644
--- a/src/test/regress/expected/oidjoins.out
+++ b/src/test/regress/expected/oidjoins.out
@@ -266,3 +266,7 @@ NOTICE: checking pg_subscription {subdbid} => pg_database {oid}
NOTICE: checking pg_subscription {subowner} => pg_authid {oid}
NOTICE: checking pg_subscription_rel {srsubid} => pg_subscription {oid}
NOTICE: checking pg_subscription_rel {srrelid} => pg_class {oid}
+NOTICE: checking pg_variable {vartype} => pg_type {oid}
+NOTICE: checking pg_variable {varnamespace} => pg_namespace {oid}
+NOTICE: checking pg_variable {varowner} => pg_authid {oid}
+NOTICE: checking pg_variable {varcollation} => pg_collation {oid}
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 6543e90de75..65d8847e60a 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6021,6 +6021,30 @@ COMMIT;
# final ON_ERROR_ROLLBACK: off
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | |
+(1 row)
+
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | =r/regress_variable_owner |
+(1 row)
+
+DROP VARIABLE var1;
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
-- check describing invalid multipart names
\dA regression.heap
improper qualified name (too many dotted names): regression.heap
@@ -6242,6 +6266,12 @@ cross-database references are not implemented: nonesuch.public.func_deps_stat
improper qualified name (too many dotted names): regression.myevt
\dy nonesuch.myevt
improper qualified name (too many dotted names): nonesuch.myevt
+\dV host.regression.public.var
+improper qualified name (too many dotted names): host.regression.public.var
+\dV regression|mydb.public.var
+cross-database references are not implemented: regression|mydb.public.var
+\dV nonesuch.public.var
+cross-database references are not implemented: nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
List of access methods
@@ -6476,6 +6506,12 @@ List of schemas
------+-------+-------+---------+----------+------
(0 rows)
+\dV "no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
improper qualified name (too many dotted names): "no.such.schema"."no.such.access.method"
@@ -6645,6 +6681,12 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
List of tables
@@ -6778,6 +6820,12 @@ List of text search templates
--------+------+------------+-----------+--------------+-----
(0 rows)
+\dV regression."no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -6825,6 +6873,8 @@ cross-database references are not implemented: "no.such.database"."no.such.schem
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
+cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
CREATE ROLE regress_du_role1;
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
new file mode 100644
index 00000000000..c36660ce6d3
--- /dev/null
+++ b/src/test/regress/expected/session_variables.out
@@ -0,0 +1,433 @@
+CREATE ROLE regress_variable_owner;
+SET log_statement TO ddl;
+-- should be ok
+CREATE VARIABLE var1 AS int;
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+ERROR: session variable cannot be pseudo-type anyelement
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+NOTICE: session variable "var2" does not exist, skipping
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+NOTICE: session variable "var1" already exists, skipping
+-- should fail
+CREATE VARIABLE var1 AS int;
+ERROR: session variable "var1" already exists
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TABLE t1;
+ERROR: cannot drop table t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+ERROR: cannot alter table "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TABLE t1;
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TYPE t1;
+ERROR: cannot drop type t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+ERROR: cannot alter type "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TYPE t1;
+SET log_statement TO default;
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+CREATE VARIABLE var1 AS testvar_domain;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter domain "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS testvar_type;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter type "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+NOTICE: NORMAL: orig=t normal=f istemp=f type=session variable identity=public.var1 name={public,var1} args={}
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+ obj_description
+-----------------------
+ some variable comment
+(1 row)
+
+DROP VARIABLE var1;
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+ varname | descr | type | object_names | object_args | ident
+---------------+-----------------------------------------+------------------+--------------------------+-------------+--------------------------------------------------------------------
+ svartest_var1 | session variable vartest1.svartest_var1 | session variable | {vartest1,svartest_var1} | {} | ("session variable",vartest1,svartest_var1,vartest1.svartest_var1)
+ svartest_var1 | session variable vartest2.svartest_var1 | session variable | {vartest2,svartest_var1} | {} | ("session variable",vartest2,svartest_var1,vartest2.svartest_var1)
+(2 rows)
+
+DROP SCHEMA vartest1 CASCADE;
+NOTICE: drop cascades to session variable vartest1.svartest_var1
+DROP SCHEMA vartest2 CASCADE;
+NOTICE: drop cascades to session variable vartest2.svartest_var1
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE ROLE regress_variable_reader;
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+DROP VARIABLE public.varxx;
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE public.var1 AS int;
+SET search_path TO public;
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+SET ROLE TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+--
+-- end of function has_session_variable_privilege tests.
+--
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+DROP VARIABLE public.var1;
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+DROP ROLE regress_variable_owner;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 37b6d21e1f9..4f136fb4745 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -111,7 +111,7 @@ test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath sqljson
# NB: temp.sql does a reconnect which transiently uses 2 connections,
# so keep this parallel group to at most 19 tests
# ----------
-test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml
+test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml session_variables
# ----------
# Another group of parallel tests
diff --git a/src/test/regress/sql/dependency.sql b/src/test/regress/sql/dependency.sql
index 8d74ed7122c..6c18b7f840a 100644
--- a/src/test/regress/sql/dependency.sql
+++ b/src/test/regress/sql/dependency.sql
@@ -114,3 +114,17 @@ DROP USER regress_dep_user2;
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+
+-- should fail
+DROP DOMAIN vardomain;
+DROP TYPE vartype;
+
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index 97d1be3aac3..6e0056dc5d6 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -1642,6 +1642,19 @@ COMMIT;
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+DROP VARIABLE var1;
+
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
+
-- check describing invalid multipart names
\dA regression.heap
\dA nonesuch.heap
@@ -1753,6 +1766,9 @@ DROP FUNCTION psql_error;
\dX nonesuch.public.func_deps_stat
\dy regression.myevt
\dy nonesuch.myevt
+\dV host.regression.public.var
+\dV regression|mydb.public.var
+\dV nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
@@ -1794,6 +1810,8 @@ DROP FUNCTION psql_error;
\dx "no.such.installed.extension"
\dX "no.such.extended.statistics"
\dy "no.such.event.trigger"
+\dV "no.such.variable"
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
@@ -1834,6 +1852,7 @@ DROP FUNCTION psql_error;
\dx "no.such.schema"."no.such.installed.extension"
\dX "no.such.schema"."no.such.extended.statistics"
\dy "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
@@ -1858,6 +1877,7 @@ DROP FUNCTION psql_error;
\dP regression."no.such.schema"."no.such.partitioned.relation"
\dT regression."no.such.schema"."no.such.data.type"
\dX regression."no.such.schema"."no.such.extended.statistics"
+\dV regression."no.such.schema"."no.such.variable"
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -1883,6 +1903,7 @@ DROP FUNCTION psql_error;
\dP "no.such.database"."no.such.schema"."no.such.partitioned.relation"
\dT "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
new file mode 100644
index 00000000000..eeb0f94ca3c
--- /dev/null
+++ b/src/test/regress/sql/session_variables.sql
@@ -0,0 +1,297 @@
+CREATE ROLE regress_variable_owner;
+
+SET log_statement TO ddl;
+
+-- should be ok
+CREATE VARIABLE var1 AS int;
+
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+
+-- should fail
+CREATE VARIABLE var1 AS int;
+
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TABLE t1;
+
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TABLE t1;
+
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TYPE t1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+SET log_statement TO default;
+
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+
+CREATE VARIABLE var1 AS testvar_domain;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+CREATE VARIABLE var1 AS testvar_type;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+
+DROP VARIABLE var1;
+
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+
+DROP SCHEMA vartest1 CASCADE;
+DROP SCHEMA vartest2 CASCADE;
+
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+
+CREATE ROLE regress_variable_reader;
+
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+
+DROP VARIABLE public.varxx;
+
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE public.var1 AS int;
+
+SET search_path TO public;
+
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+
+SET ROLE TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+--
+-- end of function has_session_variable_privilege tests.
+--
+
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+
+DROP VARIABLE public.var1;
+
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+
+DROP ROLE regress_variable_owner;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 93339ef3c58..d579941278a 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -547,6 +547,7 @@ CreateRoleStmt
CreateSchemaStmt
CreateSchemaStmtContext
CreateSeqStmt
+CreateSessionVarStmt
CreateStatsStmt
CreateStmt
CreateStmtContext
@@ -887,6 +888,7 @@ FormData_pg_ts_parser
FormData_pg_ts_template
FormData_pg_type
FormData_pg_user_mapping
+FormData_pg_variable
FormExtraData_pg_attribute
Form_pg_aggregate
Form_pg_am
@@ -946,6 +948,7 @@ Form_pg_ts_parser
Form_pg_ts_template
Form_pg_type
Form_pg_user_mapping
+Form_pg_variable
FormatNode
FreeBlockNumberArray
FreeListData
@@ -3131,6 +3134,7 @@ VarString
VarStringSortSupport
Variable
VariableAssignHook
+VariableInfo
VariableSetKind
VariableSetStmt
VariableShowStmt
--
2.48.1
[text/x-patch] v20250317-0007-GUC-session_variables_ambiguity_warning.patch (15.1K, ../../CAFj8pRC_2tHski1K4hUMZm0+T4y7na4d8hwgMMF7Y0MXhfUhbg@mail.gmail.com/9-v20250317-0007-GUC-session_variables_ambiguity_warning.patch)
download | inline diff:
From c1f4e785ff7ec744be91216a036ae4388e0771a0 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 21 May 2024 17:55:24 +0200
Subject: [PATCH 07/21] GUC session_variables_ambiguity_warning
Inside an query the session variables can be shadowed. This behaviour is by design,
because this ensuring so new variables doesn't break existing queries. But this
behaviour can be confusing, because shadowing is quiet.
When new GUC session_variables_ambiguity_warning is on, then the warning
is displayed, when some session variable can be used, but it is not used
due shadowing. This feature should to help with investigation of unexpected
behaviour.
Note: PLpgSQL has an option that controls priority of identifier's spaces
(SQL or PLpgSQL). Default behaviour doesn't allows collisions. I believe
this default is the best. I cannot to implement similar very strict
behaviour to session variables, because one unhappy named session variable
can breaks an applications. The problems related to badly named PLpgSQL's
varible is limitted just to only one routine.
---
doc/src/sgml/config.sgml | 60 +++++++++++++++++++
doc/src/sgml/ddl.sgml | 11 ++++
src/backend/parser/parse_expr.c | 49 +++++++++++++--
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/parser/parse_expr.h | 1 +
.../src/expected/plpgsql_session_variable.out | 33 ++++++++++
.../src/sql/plpgsql_session_variable.sql | 29 +++++++++
.../regress/expected/session_variables.out | 26 ++++++++
src/test/regress/sql/session_variables.sql | 26 ++++++++
10 files changed, 241 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 3d62c8bd274..4e416cc5892 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11126,6 +11126,66 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-ambiguity-warning" xreflabel="session_variables_ambiguity_warning">
+ <term><varname>session_variables_ambiguity_warning</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_ambiguity_warning</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when any identifier in a query could be
+ used as both a column identifier, routine variable or a session
+ variable identifier. The default is <literal>off</literal>.
+ </para>
+ <para>
+ Session variables can be shadowed by column references in a query, this
+ is an expected behavior. Previously working queries shouldn't error out
+ by creating any session variable, so session variables are always shadowed
+ if an identifier is ambiguous. Variables should be referenced using
+ anunambiguous identifier without any possibility for a collision with
+ identifier of other database objects (column names or record fields names).
+ The warning messages emitted when enabling <varname>session_variables_ambiguity_warning</varname>
+ can help finding such identifier collision.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE a int;
+LET a = 100;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+ a
+----
+ 10
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_ambiguity_warning TO on;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a FROM foo;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a
+----
+ 10
+(1 row)
+</screen>
+ </para>
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. For testing or development environments it's recommended to
+ enable it if you use session variables.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 147b816370e..6c1ca4a95fd 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5443,6 +5443,17 @@ SELECT name FROM foo;
Alice
</programlisting>
</para>
+
+ <para>
+ When a query contains identifiers or qualified identifiers that could be
+ used as both a session variable identifiers and as column identifier,
+ then the column identifier is preferred every time. Warnings can be
+ emitted when this situation happens by enabling configuration parameter <xref
+ linkend="guc-session-variables-ambiguity-warning"/>. User can explicitly
+ qualify the source object by syntax <literal>table.column</literal> or
+ <literal>schema.variable</literal>. It is strongly recommended to rename
+ shadowed variables or use qualified names always.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 55e4906ad76..dccc5030438 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -45,6 +45,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
+bool session_variables_ambiguity_warning = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -960,11 +961,51 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
*
* SELECT foo.a, foo.b, foo.c FROM foo;
*
- * However, that is very confusing, so we disallow it. We don't try to
- * identify a variable if we know that it would be shadowed.
- * -----
+ * However, that is very confusing, so we disallow it.
+ *
+ * When session_variables_ambiguity_warning is requested, then we
+ * need to identify a variable although we know, so this variable
+ * would be shadowed.
*/
- if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ if (node || (relname && crerr == CRERR_NO_COLUMN))
+ {
+ /*
+ * In this path we just try (if it is wanted) detect if session
+ * variable is shadowed.
+ */
+ if (session_variables_ambiguity_warning)
+ {
+ /*
+ * The AccessShareLock is created on related session variable.
+ * The lock will be kept for the whole transaction.
+ */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, true);
+
+ if (OidIsValid(varid))
+ {
+ /* this path will ending by WARNING. Unlock variable first */
+ UnlockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (node)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is shadowed",
+ NameListToString(cref->fields)),
+ errdetail("Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name."),
+ parser_errposition(pstate, cref->location)));
+ else
+ /* session variable is shadowed by RTE */
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s.%s\" is shadowed",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ errdetail("Session variables can be shadowed by tables or table's aliases with the same name."),
+ parser_errposition(pstate, cref->location)));
+ }
+ }
+ }
+ else
{
/* takes an AccessShareLock on the session variable */
varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 9c0b10ad4dc..fce97e4facd 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1628,6 +1628,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_ambiguity_warning", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when reference to a session variable is ambiguous."),
+ NULL
+ },
+ &session_variables_ambiguity_warning,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 8de86e0c945..85171c5ea23 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -742,6 +742,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_read_only = off
#default_transaction_deferrable = off
#session_replication_role = 'origin'
+#session_variables_ambiguity_warning = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index efbaff8e710..d2209070181 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -17,6 +17,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
+extern PGDLLIMPORT bool session_variables_ambiguity_warning;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index ab779900596..a6523f7afe2 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -354,6 +354,39 @@ $$;
NOTICE: session variable is 100
NOTICE: plpgsql variable is 1000
NOTICE: variable is 1000
+-- againt with session_variables_ambiguity_warning(on)
+SET session_variables_ambiguity_warning TO on;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+WARNING: session variable "plpgsql_sv_var1" is shadowed
+LINE 1: plpgsql_sv_var1
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+QUERY: plpgsql_sv_var1
+NOTICE: variable is 1000
+SET session_variables_ambiguity_warning TO off;
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
CREATE VARIABLE plpgsql_sv_v text;
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
index a3cc264cf38..9b8e90e81fa 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -260,6 +260,35 @@ BEGIN
END;
$$;
+-- againt with session_variables_ambiguity_warning(on)
+
+SET session_variables_ambiguity_warning TO on;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+SET session_variables_ambiguity_warning TO off;
+
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 2783caa8446..7c350ad5ef9 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1524,6 +1524,9 @@ CREATE TABLE vartest_foo(a int, b int);
INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
-- should to fail
SELECT var1.* FROM vartest_foo;
ERROR: missing FROM-clause entry for table "var1"
@@ -1549,6 +1552,7 @@ SELECT count(var1.*) FROM vartest_foo var1;
2
(1 row)
+SET session_variables_ambiguity_warning TO off;
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
NOTICE: drop cascades to 2 other objects
@@ -1943,3 +1947,25 @@ SELECT var1;
(1 row)
DROP VARIABLE var1, var2;
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+CREATE VARIABLE xxtab.avar int;
+CREATE TABLE public.xxtab(avar int);
+INSERT INTO public.xxtab VALUES(1);
+LET xxtab.avar = 20;
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+WARNING: session variable "xxtab.avar" is shadowed
+LINE 1: SELECT xxtab.avar FROM public.xxtab;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ avar
+------
+ 1
+(1 row)
+
+SET session_variables_ambiguity_warning TO off;
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
+NOTICE: drop cascades to session variable xxtab.avar
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index a624ab8b67f..68be415bf26 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1079,6 +1079,10 @@ INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
+
-- should to fail
SELECT var1.* FROM vartest_foo;
@@ -1091,6 +1095,8 @@ SELECT count(var1.*) FROM vartest_foo;
-- should be ok
SELECT count(var1.*) FROM vartest_foo var1;
+SET session_variables_ambiguity_warning TO off;
+
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
@@ -1334,3 +1340,23 @@ BEGIN; DROP VARIABLE var1; ROLLBACK;
SELECT var1;
DROP VARIABLE var1, var2;
+
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+
+CREATE VARIABLE xxtab.avar int;
+
+CREATE TABLE public.xxtab(avar int);
+
+INSERT INTO public.xxtab VALUES(1);
+
+LET xxtab.avar = 20;
+
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+
+SET session_variables_ambiguity_warning TO off;
+
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
--
2.48.1
[text/x-patch] v20250317-0008-variable-fence-syntax-support-and-variable-fence-usa.patch (19.5K, ../../CAFj8pRC_2tHski1K4hUMZm0+T4y7na4d8hwgMMF7Y0MXhfUhbg@mail.gmail.com/10-v20250317-0008-variable-fence-syntax-support-and-variable-fence-usa.patch)
download | inline diff:
From 45f092d71c962a8213c97458537a1eda859779db Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 19 Nov 2024 08:14:53 +0100
Subject: [PATCH 08/21] variable fence syntax support and variable fence usage
guard support
this patch introduces a concept of variable fence - syntax for variable
reference `VARIABLE(varname)` that is not in collision with column reference.
When variable fence usage guard warning is active, then usage variable
without variable fence in the case, where there can be column references,
the the warning is raised.
initial implementation of variable fence
---
doc/src/sgml/config.sgml | 65 ++++++++++++++++
doc/src/sgml/ddl.sgml | 15 ++++
src/backend/nodes/nodeFuncs.c | 6 ++
src/backend/parser/gram.y | 28 ++++++-
src/backend/parser/parse_expr.c | 74 ++++++++++++++++++-
src/backend/parser/parse_target.c | 7 ++
src/backend/utils/adt/ruleutils.c | 12 ++-
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/nodes/parsenodes.h | 10 +++
src/include/nodes/primnodes.h | 2 +
src/include/parser/parse_expr.h | 1 +
.../regress/expected/session_variables.out | 59 +++++++++++++++
src/test/regress/sql/session_variables.sql | 41 ++++++++++
14 files changed, 323 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 4e416cc5892..b16e081a242 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11186,6 +11186,71 @@ DETAIL: Session variables can be shadowed by columns, routine's variables and r
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-use-fence-warning-guard" xreflabel="session_variables_use_fence_warning_guard">
+ <term><varname>session_variables_use_fence_warning_guard</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_use_fence_warning_guard</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when a session variable identifier is used
+ inside a query without variable fence. The default is <literal>off</literal>.
+ The warning is raised only when variable is used in places, where an
+ collisions with column names is possible.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE b int;
+LET b = 100;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_use_fence_warning_guard TO on;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "b" is not used inside variable fence
+LINE 1: SELECT a, b FROM foo;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SELECT a, VARIABLE(b) FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+ </para>
+
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. Unless another collision resolution technique is used
+ (dedicated schema or using prefixes like <literal>_</literal>),
+ the use of variable fence syntax is strongly recommended, and this
+ warning should be enabled.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 6c1ca4a95fd..d6f39508c79 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5454,6 +5454,21 @@ SELECT name FROM foo;
<literal>schema.variable</literal>. It is strongly recommended to rename
shadowed variables or use qualified names always.
</para>
+
+ <para><firstterm>Variable fence</firstterm> is special syntax for session
+ variable identifier. Only name or qualified name can be used inside the
+ variable fence, and this name is used as only session variable identifier.
+<programlisting>
+SELECT VARIABLE(current_user_id);
+</programlisting>
+ </para>
+
+ <para>
+ When there is a risk of possible collisions between variable identifiers
+ and column names, then using variable fence syntax can be recommended.
+ Usage session variable without variable fence can be detected by
+ warning <xref linkend="guc-session-variables-use-fence-warning-guard"/>.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d8fc3d9fa69..575365eefcd 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1673,6 +1673,9 @@ exprLocation(const Node *expr)
case T_ParamRef:
loc = ((const ParamRef *) expr)->location;
break;
+ case T_VariableFence:
+ loc = ((const VariableFence *) expr)->location;
+ break;
case T_A_Const:
loc = ((const A_Const *) expr)->location;
break;
@@ -4715,6 +4718,9 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_VariableFence:
+ /* we assume the fields contain nothing interesting */
+ break;
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 81ae5274ec6..9afb1048b14 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -525,7 +525,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <node> def_arg columnElem where_clause where_or_current_clause
a_expr b_expr c_expr AexprConst indirection_el opt_slice_bound
columnref in_expr having_clause func_table xmltable array_expr
- OptWhereClause operator_def_arg
+ OptWhereClause operator_def_arg variable_fence
%type <list> opt_column_and_period_list
%type <list> rowsfrom_item rowsfrom_list opt_col_def_list
%type <boolean> opt_ordinality opt_without_overlaps
@@ -882,7 +882,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
*/
%nonassoc UNBOUNDED NESTED /* ideally would have same precedence as IDENT */
%nonassoc IDENT PARTITION RANGE ROWS GROUPS PRECEDING FOLLOWING CUBE ROLLUP
- SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH
+ SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH VARIABLE
%left Op OPERATOR /* multi-character ops and user-defined operators */
%left '+' '-'
%left '*' '/' '%'
@@ -15696,6 +15696,19 @@ c_expr: columnref { $$ = $1; }
else
$$ = $2;
}
+ | variable_fence opt_indirection
+ {
+ if ($2)
+ {
+ A_Indirection *n = makeNode(A_Indirection);
+
+ n->arg = (Node *) $1;
+ n->indirection = check_indirection($2, yyscanner);
+ $$ = (Node *) n;
+ }
+ else
+ $$ = $1;
+ }
| case_expr
{ $$ = $1; }
| func_expr
@@ -17082,6 +17095,17 @@ case_arg: a_expr { $$ = $1; }
| /*EMPTY*/ { $$ = NULL; }
;
+variable_fence:
+ VARIABLE '(' any_name ')'
+ {
+ VariableFence *vf = makeNode(VariableFence);
+
+ vf->varname = $3;
+ vf->location = @3;
+ $$ = (Node *) vf;
+ }
+ ;
+
columnref: ColId
{
$$ = makeColumnRef($1, NIL, @1, yyscanner);
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index dccc5030438..a439a156216 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -46,6 +46,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
bool session_variables_ambiguity_warning = false;
+bool session_variables_use_fence_warning_guard = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -81,6 +82,7 @@ static Node *transformWholeRowRef(ParseState *pstate,
static Node *transformIndirection(ParseState *pstate, A_Indirection *ind);
static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
static Node *transformCollateClause(ParseState *pstate, CollateClause *c);
+static Node *transformVariableFence(ParseState *pstate, VariableFence *vf);
static Node *transformJsonObjectConstructor(ParseState *pstate,
JsonObjectConstructor *ctor);
static Node *transformJsonArrayConstructor(ParseState *pstate,
@@ -112,7 +114,7 @@ static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
static Node *makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location);
+ char *attrname, bool fenced, int location);
/*
@@ -377,6 +379,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
result = transformJsonFuncExpr(pstate, (JsonFuncExpr *) expr);
break;
+ case T_VariableFence:
+ result = transformVariableFence(pstate, (VariableFence *) expr);
+ break;
+
default:
/* should not reach here */
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
@@ -1028,7 +1034,20 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
node = makeParamSessionVariable(pstate,
varid, typid, typmod, collid,
- attrname, cref->location);
+ attrname, false, cref->location);
+
+ /*
+ * The variable is not inside variable's fence, so raise warning
+ * when variable fence guard is active and the query has FROM
+ * clause.
+ */
+ if (session_variables_use_fence_warning_guard && pstate->p_rtable)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is not used inside variable fence",
+ NameListToString(cref->fields)),
+ errdetail("The collision of session variable' names and column names is possible."),
+ parser_errposition(pstate, cref->location)));
}
}
}
@@ -1071,7 +1090,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
static Node *
makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location)
+ char *attrname, bool fenced, int location)
{
Param *param;
@@ -1079,6 +1098,7 @@ makeParamSessionVariable(ParseState *pstate,
param->paramkind = PARAM_VARIABLE;
param->paramvarid = varid;
+ param->paramvarfenced = fenced;
param->paramtype = typid;
param->paramtypmod = typmod;
param->paramcollid = collid;
@@ -1157,6 +1177,54 @@ transformParamRef(ParseState *pstate, ParamRef *pref)
return result;
}
+static Node *
+transformVariableFence(ParseState *pstate, VariableFence *vf)
+{
+ Node *result;
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* VariableFence can be used only in context when variables are supported */
+ if (!expr_kind_allows_session_variables(pstate->p_expr_kind))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable reference is not supported here"),
+ parser_errposition(pstate, vf->location)));
+
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(vf->varname, &attrname, ¬_unique, false);
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ result = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, true, vf->location);
+ }
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ return result;
+}
+
/* Test whether an a_expr is a plain NULL constant or not */
static bool
exprIsNullConstant(Node *arg)
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d5..cf01bff65a9 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -2034,6 +2034,13 @@ FigureColnameInternal(Node *node, char **name)
(int) ((JsonFuncExpr *) node)->op);
}
break;
+ case T_VariableFence:
+ {
+ /* return last field name */
+ *name = strVal(llast(((VariableFence *) node)->varname));
+ return 2;
+ }
+ break;
default:
break;
}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index d6bdae9af7d..e0e15d1c64c 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8734,8 +8734,16 @@ get_parameter(Param *param, deparse_context *context)
/* translate paramvarid to session variable name */
if (param->paramkind == PARAM_VARIABLE)
{
- appendStringInfo(context->buf, "%s",
- generate_session_variable_name(param->paramvarid));
+ if (param->paramvarfenced)
+ {
+ appendStringInfo(context->buf, "VARIABLE(%s)",
+ generate_session_variable_name(param->paramvarid));
+ }
+ else
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ }
return;
}
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index fce97e4facd..ffe711d72a7 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1637,6 +1637,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_use_fence_warning_guard", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when variable is not used inside variable fence."),
+ NULL
+ },
+ &session_variables_use_fence_warning_guard,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 85171c5ea23..ee8bb111572 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -743,6 +743,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_deferrable = off
#session_replication_role = 'origin'
#session_variables_ambiguity_warning = off
+#session_variables_use_fence_warning_guard = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 33d03c8f174..7d7ed1b8d9d 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -321,6 +321,16 @@ typedef struct ParamRef
ParseLoc location; /* token location, or -1 if unknown */
} ParamRef;
+/*
+ * VariableFence - ensure so fields will be interpretted as a variable
+ */
+typedef struct VariableFence
+{
+ NodeTag type;
+ List *varname; /* variable name (String nodes) */
+ ParseLoc location; /* token location, or -1 if unknown */
+} VariableFence;
+
/*
* A_Expr - infix, prefix, and postfix expressions
*/
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 24033045746..be63a8d0645 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -411,6 +411,8 @@ typedef struct Param
* param is used just for execution of UPDATE operation.
*/
bool parambasenode;
+ /* true when variable is used inside an fence */
+ bool paramvarfenced;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index d2209070181..5bde43758d1 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -18,6 +18,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
extern PGDLLIMPORT bool session_variables_ambiguity_warning;
+extern PGDLLIMPORT bool session_variables_use_fence_warning_guard;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7c350ad5ef9..9ac08a14e0b 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1969,3 +1969,62 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
NOTICE: drop cascades to session variable xxtab.avar
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+CREATE SCHEMA testvar;
+SET search_path TO 'testvar';
+CREATE VARIABLE a AS int;
+LET a = 10;
+CREATE TABLE test_table(a int, b int);
+INSERT INTO test_table VALUES(20, 20);
+-- no warning
+SELECT a;
+ a
+----
+ 10
+(1 row)
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a | b
+----+----
+ 20 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a) FROM test_table;
+ a
+----
+ 10
+(1 row)
+
+ALTER TABLE test_table DROP COLUMN a;
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is not used inside variable fence
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+DROP SCHEMA testvar;
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 68be415bf26..c5420183d94 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1360,3 +1360,44 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
+
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+
+CREATE SCHEMA testvar;
+
+SET search_path TO 'testvar';
+
+CREATE VARIABLE a AS int;
+LET a = 10;
+
+CREATE TABLE test_table(a int, b int);
+
+INSERT INTO test_table VALUES(20, 20);
+
+-- no warning
+SELECT a;
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a) FROM test_table;
+
+ALTER TABLE test_table DROP COLUMN a;
+
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+
+DROP SCHEMA testvar;
+
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
--
2.48.1
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-03-17 20:52 ` Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Marcos Pegoraro @ 2025-03-17 20:52 UTC (permalink / raw)
To: Pavel Stehule <[email protected]>; +Cc: jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
Em seg., 17 de mar. de 2025 às 15:33, Pavel Stehule <[email protected]>
escreveu:
> I was asked for sending a reduced patchset
>
Would be good to explain what this reduced patchset is.
Complete patch contains this and that
Reduced patch contains only this.
Regards
Marcos
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
@ 2025-03-18 05:46 ` Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Pavel Stehule @ 2025-03-18 05:46 UTC (permalink / raw)
To: Marcos Pegoraro <[email protected]>; +Cc: jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
Hi
po 17. 3. 2025 v 21:53 odesílatel Marcos Pegoraro <[email protected]>
napsal:
> Em seg., 17 de mar. de 2025 às 15:33, Pavel Stehule <
> [email protected]> escreveu:
>
>> I was asked for sending a reduced patchset
>>
>
> Would be good to explain what this reduced patchset is.
> Complete patch contains this and that
> Reduced patch contains only this.
>
Reduced patch contains:
* possibility to create and drop session variables (support for catalog
pg_variable and related operations)
* possibility to set the session variable (command LET) and possibility to
use session variable in the query
* access right support
* support for DISCARD command
* memory cleaning at transaction end when the variable is dropped
* warning when variable is shadowed by column
* introduction of variable's fences - syntax VARIABLE(varname)
Complete patch contains plus
* LET can be described by EXPLAIN
* LET can be prepared statement
* temporary session variables
* RESET at transaction end
* implementation of DEFAULT value for the variable
* implementation IMMUTABLE and NOT NULL clauses for the variable
* variable can be used as an argument of CALL statement (and doesn't block
simple evaluation in plpgsql)
* used variable doesn't block with parallel execution
* LET from plpgsql can use simple expression evaluation (performance
optimization for PL/pgSQL)
* variables doesn't block inlining SQL functions
* fix message "column doesn't exist" to "column or variable doesn't exist"
* support for transactional variables (content can be transactional)
* possibility to specify the name of restored variable for pg_restore
Regards
Pavel
>
> Regards
> Marcos
>
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-04-02 06:46 ` Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Pavel Stehule @ 2025-04-02 06:46 UTC (permalink / raw)
To: Marcos Pegoraro <[email protected]>; +Cc: jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
Hi
necessary rebase
Regards
Pavel
Attachments:
[text/x-patch] v20250402-0007-GUC-session_variables_ambiguity_warning.patch (15.1K, ../../CAFj8pRAK_8ym1J=SAdin-vtL0PAachXgjWgU3QrhzinRdBX2sw@mail.gmail.com/3-v20250402-0007-GUC-session_variables_ambiguity_warning.patch)
download | inline diff:
From f516b498a5d6f1e6bae0aecdcba0343596c1c41a Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 21 May 2024 17:55:24 +0200
Subject: [PATCH 07/21] GUC session_variables_ambiguity_warning
Inside an query the session variables can be shadowed. This behaviour is by design,
because this ensuring so new variables doesn't break existing queries. But this
behaviour can be confusing, because shadowing is quiet.
When new GUC session_variables_ambiguity_warning is on, then the warning
is displayed, when some session variable can be used, but it is not used
due shadowing. This feature should to help with investigation of unexpected
behaviour.
Note: PLpgSQL has an option that controls priority of identifier's spaces
(SQL or PLpgSQL). Default behaviour doesn't allows collisions. I believe
this default is the best. I cannot to implement similar very strict
behaviour to session variables, because one unhappy named session variable
can breaks an applications. The problems related to badly named PLpgSQL's
varible is limitted just to only one routine.
---
doc/src/sgml/config.sgml | 60 +++++++++++++++++++
doc/src/sgml/ddl.sgml | 11 ++++
src/backend/parser/parse_expr.c | 49 +++++++++++++--
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/parser/parse_expr.h | 1 +
.../src/expected/plpgsql_session_variable.out | 33 ++++++++++
.../src/sql/plpgsql_session_variable.sql | 29 +++++++++
.../regress/expected/session_variables.out | 26 ++++++++
src/test/regress/sql/session_variables.sql | 26 ++++++++
10 files changed, 241 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index fea683cb49c..0069e785c79 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11330,6 +11330,66 @@ dynamic_library_path = '/usr/local/lib/postgresql:$libdir'
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-ambiguity-warning" xreflabel="session_variables_ambiguity_warning">
+ <term><varname>session_variables_ambiguity_warning</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_ambiguity_warning</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when any identifier in a query could be
+ used as both a column identifier, routine variable or a session
+ variable identifier. The default is <literal>off</literal>.
+ </para>
+ <para>
+ Session variables can be shadowed by column references in a query, this
+ is an expected behavior. Previously working queries shouldn't error out
+ by creating any session variable, so session variables are always shadowed
+ if an identifier is ambiguous. Variables should be referenced using
+ anunambiguous identifier without any possibility for a collision with
+ identifier of other database objects (column names or record fields names).
+ The warning messages emitted when enabling <varname>session_variables_ambiguity_warning</varname>
+ can help finding such identifier collision.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE a int;
+LET a = 100;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+ a
+----
+ 10
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_ambiguity_warning TO on;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a FROM foo;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a
+----
+ 10
+(1 row)
+</screen>
+ </para>
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. For testing or development environments it's recommended to
+ enable it if you use session variables.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index fce5e72bbf6..d73d84d6676 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5449,6 +5449,17 @@ SELECT name FROM foo;
Alice
</programlisting>
</para>
+
+ <para>
+ When a query contains identifiers or qualified identifiers that could be
+ used as both a session variable identifiers and as column identifier,
+ then the column identifier is preferred every time. Warnings can be
+ emitted when this situation happens by enabling configuration parameter <xref
+ linkend="guc-session-variables-ambiguity-warning"/>. User can explicitly
+ qualify the source object by syntax <literal>table.column</literal> or
+ <literal>schema.variable</literal>. It is strongly recommended to rename
+ shadowed variables or use qualified names always.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 55e4906ad76..dccc5030438 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -45,6 +45,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
+bool session_variables_ambiguity_warning = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -960,11 +961,51 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
*
* SELECT foo.a, foo.b, foo.c FROM foo;
*
- * However, that is very confusing, so we disallow it. We don't try to
- * identify a variable if we know that it would be shadowed.
- * -----
+ * However, that is very confusing, so we disallow it.
+ *
+ * When session_variables_ambiguity_warning is requested, then we
+ * need to identify a variable although we know, so this variable
+ * would be shadowed.
*/
- if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ if (node || (relname && crerr == CRERR_NO_COLUMN))
+ {
+ /*
+ * In this path we just try (if it is wanted) detect if session
+ * variable is shadowed.
+ */
+ if (session_variables_ambiguity_warning)
+ {
+ /*
+ * The AccessShareLock is created on related session variable.
+ * The lock will be kept for the whole transaction.
+ */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, true);
+
+ if (OidIsValid(varid))
+ {
+ /* this path will ending by WARNING. Unlock variable first */
+ UnlockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (node)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is shadowed",
+ NameListToString(cref->fields)),
+ errdetail("Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name."),
+ parser_errposition(pstate, cref->location)));
+ else
+ /* session variable is shadowed by RTE */
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s.%s\" is shadowed",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ errdetail("Session variables can be shadowed by tables or table's aliases with the same name."),
+ parser_errposition(pstate, cref->location)));
+ }
+ }
+ }
+ else
{
/* takes an AccessShareLock on the session variable */
varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 4eaeca89f2c..1ee54cfb69e 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1632,6 +1632,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_ambiguity_warning", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when reference to a session variable is ambiguous."),
+ NULL
+ },
+ &session_variables_ambiguity_warning,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index ff56a1f0732..5f5296e7b73 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -758,6 +758,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_read_only = off
#default_transaction_deferrable = off
#session_replication_role = 'origin'
+#session_variables_ambiguity_warning = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index efbaff8e710..d2209070181 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -17,6 +17,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
+extern PGDLLIMPORT bool session_variables_ambiguity_warning;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index ab779900596..a6523f7afe2 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -354,6 +354,39 @@ $$;
NOTICE: session variable is 100
NOTICE: plpgsql variable is 1000
NOTICE: variable is 1000
+-- againt with session_variables_ambiguity_warning(on)
+SET session_variables_ambiguity_warning TO on;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+WARNING: session variable "plpgsql_sv_var1" is shadowed
+LINE 1: plpgsql_sv_var1
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+QUERY: plpgsql_sv_var1
+NOTICE: variable is 1000
+SET session_variables_ambiguity_warning TO off;
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
CREATE VARIABLE plpgsql_sv_v text;
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
index a3cc264cf38..9b8e90e81fa 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -260,6 +260,35 @@ BEGIN
END;
$$;
+-- againt with session_variables_ambiguity_warning(on)
+
+SET session_variables_ambiguity_warning TO on;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+SET session_variables_ambiguity_warning TO off;
+
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 2783caa8446..7c350ad5ef9 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1524,6 +1524,9 @@ CREATE TABLE vartest_foo(a int, b int);
INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
-- should to fail
SELECT var1.* FROM vartest_foo;
ERROR: missing FROM-clause entry for table "var1"
@@ -1549,6 +1552,7 @@ SELECT count(var1.*) FROM vartest_foo var1;
2
(1 row)
+SET session_variables_ambiguity_warning TO off;
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
NOTICE: drop cascades to 2 other objects
@@ -1943,3 +1947,25 @@ SELECT var1;
(1 row)
DROP VARIABLE var1, var2;
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+CREATE VARIABLE xxtab.avar int;
+CREATE TABLE public.xxtab(avar int);
+INSERT INTO public.xxtab VALUES(1);
+LET xxtab.avar = 20;
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+WARNING: session variable "xxtab.avar" is shadowed
+LINE 1: SELECT xxtab.avar FROM public.xxtab;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ avar
+------
+ 1
+(1 row)
+
+SET session_variables_ambiguity_warning TO off;
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
+NOTICE: drop cascades to session variable xxtab.avar
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index a624ab8b67f..68be415bf26 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1079,6 +1079,10 @@ INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
+
-- should to fail
SELECT var1.* FROM vartest_foo;
@@ -1091,6 +1095,8 @@ SELECT count(var1.*) FROM vartest_foo;
-- should be ok
SELECT count(var1.*) FROM vartest_foo var1;
+SET session_variables_ambiguity_warning TO off;
+
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
@@ -1334,3 +1340,23 @@ BEGIN; DROP VARIABLE var1; ROLLBACK;
SELECT var1;
DROP VARIABLE var1, var2;
+
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+
+CREATE VARIABLE xxtab.avar int;
+
+CREATE TABLE public.xxtab(avar int);
+
+INSERT INTO public.xxtab VALUES(1);
+
+LET xxtab.avar = 20;
+
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+
+SET session_variables_ambiguity_warning TO off;
+
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
--
2.49.0
[text/x-patch] v20250402-0006-plpgsql-tests.patch (16.9K, ../../CAFj8pRAK_8ym1J=SAdin-vtL0PAachXgjWgU3QrhzinRdBX2sw@mail.gmail.com/4-v20250402-0006-plpgsql-tests.patch)
download | inline diff:
From 2a923e169283df811dfd683f7401b7cc1db101cb Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 14:06:06 +0100
Subject: [PATCH 06/21] plpgsql tests
---
src/pl/plpgsql/src/Makefile | 3 +-
.../src/expected/plpgsql_session_variable.out | 382 ++++++++++++++++++
src/pl/plpgsql/src/meson.build | 1 +
.../src/sql/plpgsql_session_variable.sql | 289 +++++++++++++
4 files changed, 674 insertions(+), 1 deletion(-)
create mode 100644 src/pl/plpgsql/src/expected/plpgsql_session_variable.out
create mode 100644 src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile
index 63cb96fae3e..bbcae27d422 100644
--- a/src/pl/plpgsql/src/Makefile
+++ b/src/pl/plpgsql/src/Makefile
@@ -35,7 +35,8 @@ REGRESS_OPTS = --dbname=$(PL_TESTDB)
REGRESS = plpgsql_array plpgsql_cache plpgsql_call plpgsql_control \
plpgsql_copy plpgsql_domain plpgsql_misc \
plpgsql_record plpgsql_simple plpgsql_transaction \
- plpgsql_trap plpgsql_trigger plpgsql_varprops
+ plpgsql_trap plpgsql_trigger plpgsql_varprops \
+ plpgsql_session_variable
# where to find gen_keywordlist.pl and subsidiary files
TOOLSDIR = $(top_srcdir)/src/tools
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
new file mode 100644
index 00000000000..ab779900596
--- /dev/null
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -0,0 +1,382 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+LET plpgsql_sv_var = pi();
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+NOTICE: value of session variable is 3.14159265358979
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+ pi_multiply_2
+------------------
+ 6.28318530717959
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var;
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+END;
+-- execute outside of a transaction
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP FUNCTION test_func();
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+SET ROLE TO regress_var_owner_role;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_reader_role;
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail
+SELECT var_read_func();
+ERROR: permission denied for session variable plpgsql_sv_var1
+CONTEXT: PL/pgSQL expression "plpgsql_sv_var1"
+PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should be ok
+SELECT var_read_func();
+NOTICE: 10
+ var_read_func
+---------------
+
+(1 row)
+
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+DROP VARIABLE plpgsql_sv_var1;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail, but not crash
+SELECT var_read_func();
+ERROR: column "plpgsql_sv_var1" does not exist
+LINE 1: plpgsql_sv_var1
+ ^
+QUERY: plpgsql_sv_var1
+CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+DROP FUNCTION var_read_func;
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+ inc_var_int
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+LET plpgsql_sv_var2 = 0.0;
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+ inc_var_num
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+NOTICE: variable is 1000
+DROP VARIABLE plpgsql_sv_var1;
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+select ffunc();
+ ffunc
+-------
+ abc
+(1 row)
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+DROP VARIABLE plpgsql_sv_v;
diff --git a/src/pl/plpgsql/src/meson.build b/src/pl/plpgsql/src/meson.build
index 33c49ac25d9..1d01d1c2629 100644
--- a/src/pl/plpgsql/src/meson.build
+++ b/src/pl/plpgsql/src/meson.build
@@ -88,6 +88,7 @@ tests += {
'plpgsql_trap',
'plpgsql_trigger',
'plpgsql_varprops',
+ 'plpgsql_session_variable',
],
},
}
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
new file mode 100644
index 00000000000..a3cc264cf38
--- /dev/null
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -0,0 +1,289 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+
+LET plpgsql_sv_var = pi();
+
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+
+DROP VARIABLE plpgsql_sv_var;
+
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+END;
+
+-- execute outside of a transaction
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+SELECT test_func();
+
+DROP FUNCTION test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+SET ROLE TO regress_var_owner_role;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_reader_role;
+
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should be ok
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail, but not crash
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+DROP FUNCTION var_read_func;
+
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+
+LET plpgsql_sv_var2 = 0.0;
+
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+
+select ffunc();
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+
+DROP VARIABLE plpgsql_sv_v;
--
2.49.0
[text/x-patch] v20250402-0005-memory-cleaning-after-DROP-VARIABLE.patch (20.9K, ../../CAFj8pRAK_8ym1J=SAdin-vtL0PAachXgjWgU3QrhzinRdBX2sw@mail.gmail.com/5-v20250402-0005-memory-cleaning-after-DROP-VARIABLE.patch)
download | inline diff:
From 2a744ee94554c94564cf7280790206dfb876c094 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 09:31:28 +0100
Subject: [PATCH 05/21] memory cleaning after DROP VARIABLE
Accepting a sinval message invalidates entries in the "sessionvars" hash table.
These entries are validated before any read or write operations on session variables.
When the entry cannot be validated, it is removed. Removal will be delayed when
the variable was dropped by the current transaction, which could still be rolled back.
---
src/backend/catalog/pg_variable.c | 7 +-
src/backend/commands/session_variable.c | 153 +++++++++++-
src/include/commands/session_variable.h | 2 +
.../isolation/expected/session-variable.out | 110 +++++++++
src/test/isolation/isolation_schedule | 1 +
.../isolation/specs/session-variable.spec | 50 ++++
.../regress/expected/session_variables.out | 217 ++++++++++++++++++
src/test/regress/sql/session_variables.sql | 120 ++++++++++
8 files changed, 655 insertions(+), 5 deletions(-)
create mode 100644 src/test/isolation/expected/session-variable.out
create mode 100644 src/test/isolation/specs/session-variable.spec
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index bb445e9434b..d672d2a9cb3 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -22,6 +22,7 @@
#include "catalog/pg_collation.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
@@ -230,7 +231,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
}
/*
- * Drop variable by OID
+ * Drop variable by OID, and register the needed session variable
+ * cleanup.
*/
void
DropVariableById(Oid varid)
@@ -250,4 +252,7 @@ DropVariableById(Oid varid)
ReleaseSysCache(tup);
table_close(rel, RowExclusiveLock);
+
+ /* do the necessary cleanup in local memory, if needed */
+ SessionVariableDropPostprocess(varid);
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index e1c86966998..1596d94fb03 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -14,6 +14,7 @@
*/
#include "postgres.h"
+#include "access/xact.h"
#include "catalog/pg_variable.h"
#include "commands/session_variable.h"
#include "executor/svariableReceiver.h"
@@ -67,6 +68,14 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ /*
+ * Top level local transaction id of the last transaction that dropped the
+ * variable, if any. We need this information to avoid freeing memory for
+ * variables dropped by the local backend, in case the operation is rolled
+ * back.
+ */
+ LocalTransactionId drop_lxid;
+
/*
* Stored value and type description can be outdated when we receive a
* sinval message. We then have to check if the stored data are still
@@ -83,6 +92,17 @@ static HTAB *sessionvars = NULL; /* hash table for session variables */
static MemoryContext SVariableMemoryContext = NULL;
+/* becomes true when we receive a sinval message */
+static bool needs_validation = false;
+
+/*
+ * The content of dropped session variables is not removed immediately. We do
+ * that in the next transaction that reads or writes a session variable.
+ * "validated_lxid" stores the transaction that performed said validation, so
+ * that we can avoid repeating the effort.
+ */
+static LocalTransactionId validated_lxid = InvalidLocalTransactionId;
+
/*
* Callback function for session variable invalidation.
*/
@@ -114,6 +134,38 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
if (hashvalue == 0 || svar->hashvalue == hashvalue)
{
svar->is_valid = false;
+ needs_validation = true;
+ }
+ }
+}
+
+/*
+ * Handle the local memory cleanup for a DROP VARIABLE command.
+ *
+ * Caller should take care of removing the pg_variable entry first.
+ */
+void
+SessionVariableDropPostprocess(Oid varid)
+{
+ Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid));
+
+ if (sessionvars)
+ {
+ bool found;
+ SVariable svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_FIND, &found);
+
+ if (found)
+ {
+ /*
+ * Save the current top level local transaction id to make sure we
+ * won't automatically remove the local variable storage in
+ * validate_all_session_variables() when the invalidation message
+ * from DROP VARIABLE arrives. After all, the transaction could
+ * still be rolled back.
+ */
+ svar->is_valid = false;
+ svar->drop_lxid = MyProc->vxid.lxid;
}
}
}
@@ -167,6 +219,67 @@ is_session_variable_valid(SVariable svar)
return result;
}
+/*
+ * Check all potentially invalid session variable data in local memory and free
+ * the memory for all invalid ones. This function is called before any read or
+ * write of a session variable. Freeing of a variable's memory is postponed if
+ * the variable has been dropped by the current transaction, since that
+ * operation could still be rolled back.
+ *
+ * It is possible that we receive a cache invalidation message while
+ * remove_invalid_session_variables() is executing, so we cannot guarantee that
+ * all entries in "sessionvars" will be set to "is_valid" after the function is
+ * done. However, we can guarantee that all entries get checked once.
+ */
+static void
+remove_invalid_session_variables(void)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ /*
+ * The validation requires system catalog access, so the session state
+ * should be "in transaction".
+ */
+ Assert(IsTransactionState());
+
+ if (!needs_validation || !sessionvars)
+ return;
+
+ /*
+ * Reset the flag before we start the validation. It can be set again
+ * by concurrently incoming sinval messages.
+ */
+ needs_validation = false;
+
+ elog(DEBUG1, "effective call of validate_all_session_variables()");
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (!svar->is_valid)
+ {
+ if (svar->drop_lxid == MyProc->vxid.lxid)
+ {
+ /* try again in the next transaction */
+ needs_validation = true;
+ continue;
+ }
+
+ if (!is_session_variable_valid(svar))
+ {
+ Oid varid = svar->varid;
+
+ free_session_variable_value(svar);
+ hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ else
+ svar->is_valid = true;
+ }
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
@@ -196,6 +309,8 @@ setup_session_variable(SVariable svar, Oid varid)
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+ svar->drop_lxid = InvalidTransactionId;
+
svar->isnull = true;
svar->value = (Datum) 0;
@@ -319,22 +434,42 @@ get_session_variable(Oid varid)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
if (found)
{
+ /*
+ * The session variable could have been dropped by a DROP VARIABLE
+ * statement in a subtransaction that was later rolled back, which
+ * means that we may have to work with the data of a variable marked
+ * as invalid.
+ */
if (!svar->is_valid)
{
/*
- * If there was an invalidation message, the variable might still be
- * valid, but we have to check with the system catalog.
+ * We have to check the system catalog to see if the variable is
+ * still valid, even if an invalidation message set it to invalid.
+ *
+ * The variable must be validated before it is accessed. The oid
+ * should be valid, because the related session variable is already
+ * locked, and remove_invalid_session_variables() would remove
+ * variables dropped by other transactions.
*/
if (is_session_variable_valid(svar))
svar->is_valid = true;
else
- /* if the value cannot be validated, we have to discard it */
- free_session_variable_value(svar);
+ elog(ERROR, "unexpected state of session variable %u", varid);
}
}
else
@@ -395,6 +530,16 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index a8ca43c87af..d3cc79b5608 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -21,6 +21,8 @@
#include "tcop/cmdtag.h"
#include "utils/queryenvironment.h"
+extern void SessionVariableDropPostprocess(Oid varid);
+
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
new file mode 100644
index 00000000000..0a5579dc7ce
--- /dev/null
+++ b/src/test/isolation/expected/session-variable.out
@@ -0,0 +1,110 @@
+Parsed test spec with 4 sessions
+
+starting permutation: let val drop val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+
+starting permutation: let val s1 drop val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+step sr1: ROLLBACK;
+
+starting permutation: let val dbg drop create dbg val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name|removed
+------+----+-------
+ | |t
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+
+starting permutation: let val s1 dbg drop create dbg val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+step sr1: ROLLBACK;
+
+starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+step create3: CREATE VARIABLE myvar3 AS text;
+step let3: LET myvar3 = 'test';
+step s3: BEGIN;
+step create4: CREATE VARIABLE myvar4 AS text;
+step let4: LET myvar4 = 'test';
+step drop4: DROP VARIABLE myvar4;
+step drop3: DROP VARIABLE myvar3;
+step inval3: SELECT COUNT(*) >= 0 FROM pg_foreign_table;
+?column?
+--------
+t
+(1 row)
+
+step discard: DISCARD VARIABLES;
+step sc3: COMMIT;
+step state: SELECT varname FROM pg_variable;
+varname
+-------
+myvar
+(1 row)
+
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 143109aa4da..7453685d046 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -115,3 +115,4 @@ test: serializable-parallel-2
test: serializable-parallel-3
test: matview-write-skew
test: lock-nowait
+test: session-variable
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
new file mode 100644
index 00000000000..c864fee4006
--- /dev/null
+++ b/src/test/isolation/specs/session-variable.spec
@@ -0,0 +1,50 @@
+# Test session variables memory cleanup for sinval
+
+setup
+{
+ CREATE VARIABLE myvar AS text;
+}
+
+teardown
+{
+ DROP VARIABLE IF EXISTS myvar;
+}
+
+session s1
+step s1 { BEGIN; }
+step let { LET myvar = 'test'; }
+step val { SELECT myvar; }
+step dbg { SELECT schema, name, removed FROM pg_session_variables(); }
+step sr1 { ROLLBACK; }
+
+session s2
+step drop { DROP VARIABLE myvar; }
+step create { CREATE VARIABLE myvar AS text; }
+
+session s3
+step s3 { BEGIN; }
+step let3 { LET myvar3 = 'test'; }
+step create4 { CREATE VARIABLE myvar4 AS text; }
+step let4 { LET myvar4 = 'test'; }
+step drop4 { DROP VARIABLE myvar4; }
+step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; }
+step discard { DISCARD VARIABLES; }
+step sc3 { COMMIT; }
+step state { SELECT varname FROM pg_variable; }
+
+session s4
+step create3 { CREATE VARIABLE myvar3 AS text; }
+step drop3 { DROP VARIABLE myvar3; }
+
+# Concurrent drop of a known variable should lead to an error
+permutation let val drop val
+# Same, but with an explicit transaction
+permutation let val s1 drop val sr1
+# Concurrent drop/create of a known variable should lead to empty variable
+permutation let val dbg drop create dbg val
+# Concurrent drop/create of a known variable should lead to empty variable
+# We need a transaction to make sure that we won't accept invalidation when
+# calling the dbg step after the concurrent drop
+permutation let val s1 dbg drop create dbg val sr1
+# test for DISCARD ALL when all internal queues have actions registered
+permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 79ac40768f8..2783caa8446 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1726,3 +1726,220 @@ SELECT count(*) FROM pg_session_variables();
0
(1 row)
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+-- should fail
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1, var2;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 2954759aaed..a624ab8b67f 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1214,3 +1214,123 @@ DISCARD VARIABLES;
-- should be zero again
SELECT count(*) FROM pg_session_variables();
+
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+
+-- should fail
+SELECT var1;
+
+ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ROLLBACK;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+DROP VARIABLE var1, var2;
--
2.49.0
[text/x-patch] v20250402-0004-DISCARD-VARIABLES.patch (9.6K, ../../CAFj8pRAK_8ym1J=SAdin-vtL0PAachXgjWgU3QrhzinRdBX2sw@mail.gmail.com/6-v20250402-0004-DISCARD-VARIABLES.patch)
download | inline diff:
From 9c17d2fc3e1554b0849d37d0f37f15f44953403c Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sun, 28 Jan 2024 20:54:20 +0100
Subject: [PATCH 04/21] DISCARD VARIABLES
Implementation of DISCARD VARIABLES commands by removing hash table with session variables
and resetting related memory context.
---
doc/src/sgml/ref/discard.sgml | 13 +++-
src/backend/commands/discard.c | 6 ++
src/backend/commands/session_variable.c | 28 ++++++++-
src/backend/parser/gram.y | 6 ++
src/backend/tcop/utility.c | 3 +
src/bin/psql/tab-complete.in.c | 2 +-
src/include/commands/session_variable.h | 2 +
src/include/nodes/parsenodes.h | 1 +
src/include/tcop/cmdtaglist.h | 1 +
.../regress/expected/session_variables.out | 63 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 36 +++++++++++
11 files changed, 158 insertions(+), 3 deletions(-)
diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
index bf44c523cac..61b967f9c9b 100644
--- a/doc/src/sgml/ref/discard.sgml
+++ b/doc/src/sgml/ref/discard.sgml
@@ -21,7 +21,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
+DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES }
</synopsis>
</refsynopsisdiv>
@@ -66,6 +66,16 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>VARIABLES</literal></term>
+ <listitem>
+ <para>
+ Resets the value of all session variables. If a variable
+ is later reused, it is re-initialized to <literal>NULL</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><literal>TEMPORARY</literal> or <literal>TEMP</literal></term>
<listitem>
@@ -93,6 +103,7 @@ SELECT pg_advisory_unlock_all();
DISCARD PLANS;
DISCARD TEMP;
DISCARD SEQUENCES;
+DISCARD VARIABLES;
</programlisting></para>
</listitem>
</varlistentry>
diff --git a/src/backend/commands/discard.c b/src/backend/commands/discard.c
index 81339a75a52..5904a6c4917 100644
--- a/src/backend/commands/discard.c
+++ b/src/backend/commands/discard.c
@@ -18,6 +18,7 @@
#include "commands/async.h"
#include "commands/discard.h"
#include "commands/prepare.h"
+#include "commands/session_variable.h"
#include "commands/sequence.h"
#include "utils/guc.h"
#include "utils/portal.h"
@@ -48,6 +49,10 @@ DiscardCommand(DiscardStmt *stmt, bool isTopLevel)
ResetTempTableNamespace();
break;
+ case DISCARD_VARIABLES:
+ ResetSessionVariables();
+ break;
+
default:
elog(ERROR, "unrecognized DISCARD target: %d", stmt->target);
}
@@ -75,4 +80,5 @@ DiscardAll(bool isTopLevel)
ResetPlanCache();
ResetTempTableNamespace();
ResetSequenceCaches();
+ ResetSessionVariables();
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index fa16f47072e..e1c86966998 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -94,7 +94,13 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
- Assert(sessionvars);
+ /*
+ * There is no guarantee of session variables being initialized, even when
+ * receiving an invalidation callback, as DISCARD [ ALL | VARIABLES ]
+ * destroys the hash table entirely.
+ */
+ if (!sessionvars)
+ return;
/*
* If the hashvalue is not specified, we have to recheck all currently
@@ -619,3 +625,23 @@ pg_session_variables(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+
+/*
+ * Fast drop of the complete content of the session variables hash table, and
+ * cleanup of any list that wouldn't be relevant anymore.
+ * This is used by the DISCARD VARIABLES (and DISCARD ALL) command.
+ */
+void
+ResetSessionVariables(void)
+{
+ /* destroy hash table and reset related memory context */
+ if (sessionvars)
+ {
+ hash_destroy(sessionvars);
+ sessionvars = NULL;
+ }
+
+ /* release memory allocated by session variables */
+ if (SVariableMemoryContext != NULL)
+ MemoryContextReset(SVariableMemoryContext);
+}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 8de7041e27b..7b2c3cd6bc6 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -2084,7 +2084,13 @@ DiscardStmt:
n->target = DISCARD_SEQUENCES;
$$ = (Node *) n;
}
+ | DISCARD VARIABLES
+ {
+ DiscardStmt *n = makeNode(DiscardStmt);
+ n->target = DISCARD_VARIABLES;
+ $$ = (Node *) n;
+ }
;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 7a508a3644f..6e4d2310f5c 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -2962,6 +2962,9 @@ CreateCommandTag(Node *parsetree)
case DISCARD_SEQUENCES:
tag = CMDTAG_DISCARD_SEQUENCES;
break;
+ case DISCARD_VARIABLES:
+ tag = CMDTAG_DISCARD_VARIABLES;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index b3d4ef54456..db64a8eeff1 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4146,7 +4146,7 @@ match_previous_words(int pattern_id,
/* DISCARD */
else if (Matches("DISCARD"))
- COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP");
+ COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP", "VARIABLES");
/* DO */
else if (Matches("DO"))
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index 2391b9ad443..a8ca43c87af 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -27,4 +27,6 @@ extern Datum GetSessionVariable(Oid varid, bool *isNull);
extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
QueryEnvironment *queryEnv, QueryCompletion *qc);
+extern void ResetSessionVariables(void);
+
#endif
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index e935515e5b5..385a9ff88fd 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -4054,6 +4054,7 @@ typedef enum DiscardMode
DISCARD_PLANS,
DISCARD_SEQUENCES,
DISCARD_TEMP,
+ DISCARD_VARIABLES,
} DiscardMode;
typedef struct DiscardStmt
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index 22082c30008..bef0ac25331 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -135,6 +135,7 @@ PG_CMDTAG(CMDTAG_DISCARD_ALL, "DISCARD ALL", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_PLANS, "DISCARD PLANS", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_SEQUENCES, "DISCARD SEQUENCES", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_TEMP, "DISCARD TEMP", false, false, false)
+PG_CMDTAG(CMDTAG_DISCARD_VARIABLES, "DISCARD VARIABLES", false, false, false)
PG_CMDTAG(CMDTAG_DO, "DO", false, false, false)
PG_CMDTAG(CMDTAG_DROP_ACCESS_METHOD, "DROP ACCESS METHOD", true, false, false)
PG_CMDTAG(CMDTAG_DROP_AGGREGATE, "DROP AGGREGATE", true, false, false)
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index f22467186e3..79ac40768f8 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1663,3 +1663,66 @@ DROP VARIABLE :"DBNAME".:"DBNAME".b;
DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+ var1
+-------
+ Hello
+(1 row)
+
+DISCARD ALL;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT var1;
+ var1
+------
+ AHOJ
+(1 row)
+
+DISCARD VARIABLES;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+DROP VARIABLE var1;
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS varchar;
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DISCARD VARIABLES;
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index e72360d5254..2954759aaed 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1178,3 +1178,39 @@ DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+
+DISCARD ALL;
+SELECT var1;
+
+LET var1 = 'AHOJ';
+SELECT var1;
+
+DISCARD VARIABLES;
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+
+SELECT count(*) FROM pg_session_variables();
+
+CREATE VARIABLE var1 AS varchar;
+
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+
+LET var1 = 'AHOJ';
+
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+
+DISCARD VARIABLES;
+
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
--
2.49.0
[text/x-patch] v20250402-0008-variable-fence-syntax-support-and-variable-fence-usa.patch (19.5K, ../../CAFj8pRAK_8ym1J=SAdin-vtL0PAachXgjWgU3QrhzinRdBX2sw@mail.gmail.com/7-v20250402-0008-variable-fence-syntax-support-and-variable-fence-usa.patch)
download | inline diff:
From 309e133542fcb5968512bc680831f7b5192160ae Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 19 Nov 2024 08:14:53 +0100
Subject: [PATCH 08/21] variable fence syntax support and variable fence usage
guard support
this patch introduces a concept of variable fence - syntax for variable
reference `VARIABLE(varname)` that is not in collision with column reference.
When variable fence usage guard warning is active, then usage variable
without variable fence in the case, where there can be column references,
the the warning is raised.
initial implementation of variable fence
---
doc/src/sgml/config.sgml | 65 ++++++++++++++++
doc/src/sgml/ddl.sgml | 15 ++++
src/backend/nodes/nodeFuncs.c | 6 ++
src/backend/parser/gram.y | 28 ++++++-
src/backend/parser/parse_expr.c | 74 ++++++++++++++++++-
src/backend/parser/parse_target.c | 7 ++
src/backend/utils/adt/ruleutils.c | 12 ++-
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/nodes/parsenodes.h | 10 +++
src/include/nodes/primnodes.h | 2 +
src/include/parser/parse_expr.h | 1 +
.../regress/expected/session_variables.out | 59 +++++++++++++++
src/test/regress/sql/session_variables.sql | 41 ++++++++++
14 files changed, 323 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 0069e785c79..ec4a0bc7d05 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11390,6 +11390,71 @@ DETAIL: Session variables can be shadowed by columns, routine's variables and r
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-use-fence-warning-guard" xreflabel="session_variables_use_fence_warning_guard">
+ <term><varname>session_variables_use_fence_warning_guard</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_use_fence_warning_guard</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when a session variable identifier is used
+ inside a query without variable fence. The default is <literal>off</literal>.
+ The warning is raised only when variable is used in places, where an
+ collisions with column names is possible.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE b int;
+LET b = 100;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_use_fence_warning_guard TO on;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "b" is not used inside variable fence
+LINE 1: SELECT a, b FROM foo;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SELECT a, VARIABLE(b) FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+ </para>
+
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. Unless another collision resolution technique is used
+ (dedicated schema or using prefixes like <literal>_</literal>),
+ the use of variable fence syntax is strongly recommended, and this
+ warning should be enabled.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index d73d84d6676..cddecf0301d 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5460,6 +5460,21 @@ SELECT name FROM foo;
<literal>schema.variable</literal>. It is strongly recommended to rename
shadowed variables or use qualified names always.
</para>
+
+ <para><firstterm>Variable fence</firstterm> is special syntax for session
+ variable identifier. Only name or qualified name can be used inside the
+ variable fence, and this name is used as only session variable identifier.
+<programlisting>
+SELECT VARIABLE(current_user_id);
+</programlisting>
+ </para>
+
+ <para>
+ When there is a risk of possible collisions between variable identifiers
+ and column names, then using variable fence syntax can be recommended.
+ Usage session variable without variable fence can be detected by
+ warning <xref linkend="guc-session-variables-use-fence-warning-guard"/>.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d8fc3d9fa69..575365eefcd 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1673,6 +1673,9 @@ exprLocation(const Node *expr)
case T_ParamRef:
loc = ((const ParamRef *) expr)->location;
break;
+ case T_VariableFence:
+ loc = ((const VariableFence *) expr)->location;
+ break;
case T_A_Const:
loc = ((const A_Const *) expr)->location;
break;
@@ -4715,6 +4718,9 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_VariableFence:
+ /* we assume the fields contain nothing interesting */
+ break;
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 7b2c3cd6bc6..df99512e6a0 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -525,7 +525,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <node> def_arg columnElem where_clause where_or_current_clause
a_expr b_expr c_expr AexprConst indirection_el opt_slice_bound
columnref in_expr having_clause func_table xmltable array_expr
- OptWhereClause operator_def_arg
+ OptWhereClause operator_def_arg variable_fence
%type <list> opt_column_and_period_list
%type <list> rowsfrom_item rowsfrom_list opt_col_def_list
%type <boolean> opt_ordinality opt_without_overlaps
@@ -882,7 +882,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
*/
%nonassoc UNBOUNDED NESTED /* ideally would have same precedence as IDENT */
%nonassoc IDENT PARTITION RANGE ROWS GROUPS PRECEDING FOLLOWING CUBE ROLLUP
- SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH
+ SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH VARIABLE
%left Op OPERATOR /* multi-character ops and user-defined operators */
%left '+' '-'
%left '*' '/' '%'
@@ -15686,6 +15686,19 @@ c_expr: columnref { $$ = $1; }
else
$$ = $2;
}
+ | variable_fence opt_indirection
+ {
+ if ($2)
+ {
+ A_Indirection *n = makeNode(A_Indirection);
+
+ n->arg = (Node *) $1;
+ n->indirection = check_indirection($2, yyscanner);
+ $$ = (Node *) n;
+ }
+ else
+ $$ = $1;
+ }
| case_expr
{ $$ = $1; }
| func_expr
@@ -17072,6 +17085,17 @@ case_arg: a_expr { $$ = $1; }
| /*EMPTY*/ { $$ = NULL; }
;
+variable_fence:
+ VARIABLE '(' any_name ')'
+ {
+ VariableFence *vf = makeNode(VariableFence);
+
+ vf->varname = $3;
+ vf->location = @3;
+ $$ = (Node *) vf;
+ }
+ ;
+
columnref: ColId
{
$$ = makeColumnRef($1, NIL, @1, yyscanner);
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index dccc5030438..a439a156216 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -46,6 +46,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
bool session_variables_ambiguity_warning = false;
+bool session_variables_use_fence_warning_guard = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -81,6 +82,7 @@ static Node *transformWholeRowRef(ParseState *pstate,
static Node *transformIndirection(ParseState *pstate, A_Indirection *ind);
static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
static Node *transformCollateClause(ParseState *pstate, CollateClause *c);
+static Node *transformVariableFence(ParseState *pstate, VariableFence *vf);
static Node *transformJsonObjectConstructor(ParseState *pstate,
JsonObjectConstructor *ctor);
static Node *transformJsonArrayConstructor(ParseState *pstate,
@@ -112,7 +114,7 @@ static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
static Node *makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location);
+ char *attrname, bool fenced, int location);
/*
@@ -377,6 +379,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
result = transformJsonFuncExpr(pstate, (JsonFuncExpr *) expr);
break;
+ case T_VariableFence:
+ result = transformVariableFence(pstate, (VariableFence *) expr);
+ break;
+
default:
/* should not reach here */
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
@@ -1028,7 +1034,20 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
node = makeParamSessionVariable(pstate,
varid, typid, typmod, collid,
- attrname, cref->location);
+ attrname, false, cref->location);
+
+ /*
+ * The variable is not inside variable's fence, so raise warning
+ * when variable fence guard is active and the query has FROM
+ * clause.
+ */
+ if (session_variables_use_fence_warning_guard && pstate->p_rtable)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is not used inside variable fence",
+ NameListToString(cref->fields)),
+ errdetail("The collision of session variable' names and column names is possible."),
+ parser_errposition(pstate, cref->location)));
}
}
}
@@ -1071,7 +1090,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
static Node *
makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location)
+ char *attrname, bool fenced, int location)
{
Param *param;
@@ -1079,6 +1098,7 @@ makeParamSessionVariable(ParseState *pstate,
param->paramkind = PARAM_VARIABLE;
param->paramvarid = varid;
+ param->paramvarfenced = fenced;
param->paramtype = typid;
param->paramtypmod = typmod;
param->paramcollid = collid;
@@ -1157,6 +1177,54 @@ transformParamRef(ParseState *pstate, ParamRef *pref)
return result;
}
+static Node *
+transformVariableFence(ParseState *pstate, VariableFence *vf)
+{
+ Node *result;
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* VariableFence can be used only in context when variables are supported */
+ if (!expr_kind_allows_session_variables(pstate->p_expr_kind))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable reference is not supported here"),
+ parser_errposition(pstate, vf->location)));
+
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(vf->varname, &attrname, ¬_unique, false);
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ result = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, true, vf->location);
+ }
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ return result;
+}
+
/* Test whether an a_expr is a plain NULL constant or not */
static bool
exprIsNullConstant(Node *arg)
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d5..cf01bff65a9 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -2034,6 +2034,13 @@ FigureColnameInternal(Node *node, char **name)
(int) ((JsonFuncExpr *) node)->op);
}
break;
+ case T_VariableFence:
+ {
+ /* return last field name */
+ *name = strVal(llast(((VariableFence *) node)->varname));
+ return 2;
+ }
+ break;
default:
break;
}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index d6bdae9af7d..e0e15d1c64c 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8734,8 +8734,16 @@ get_parameter(Param *param, deparse_context *context)
/* translate paramvarid to session variable name */
if (param->paramkind == PARAM_VARIABLE)
{
- appendStringInfo(context->buf, "%s",
- generate_session_variable_name(param->paramvarid));
+ if (param->paramvarfenced)
+ {
+ appendStringInfo(context->buf, "VARIABLE(%s)",
+ generate_session_variable_name(param->paramvarid));
+ }
+ else
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ }
return;
}
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 1ee54cfb69e..94bde564d9b 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1641,6 +1641,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_use_fence_warning_guard", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when variable is not used inside variable fence."),
+ NULL
+ },
+ &session_variables_use_fence_warning_guard,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 5f5296e7b73..9a5df498ebe 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -759,6 +759,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_deferrable = off
#session_replication_role = 'origin'
#session_variables_ambiguity_warning = off
+#session_variables_use_fence_warning_guard = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 385a9ff88fd..5c4e8332ee9 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -321,6 +321,16 @@ typedef struct ParamRef
ParseLoc location; /* token location, or -1 if unknown */
} ParamRef;
+/*
+ * VariableFence - ensure so fields will be interpretted as a variable
+ */
+typedef struct VariableFence
+{
+ NodeTag type;
+ List *varname; /* variable name (String nodes) */
+ ParseLoc location; /* token location, or -1 if unknown */
+} VariableFence;
+
/*
* A_Expr - infix, prefix, and postfix expressions
*/
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 3cc2f019abb..98bca694480 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -411,6 +411,8 @@ typedef struct Param
* param is used just for execution of UPDATE operation.
*/
bool parambasenode;
+ /* true when variable is used inside an fence */
+ bool paramvarfenced;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index d2209070181..5bde43758d1 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -18,6 +18,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
extern PGDLLIMPORT bool session_variables_ambiguity_warning;
+extern PGDLLIMPORT bool session_variables_use_fence_warning_guard;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7c350ad5ef9..9ac08a14e0b 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1969,3 +1969,62 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
NOTICE: drop cascades to session variable xxtab.avar
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+CREATE SCHEMA testvar;
+SET search_path TO 'testvar';
+CREATE VARIABLE a AS int;
+LET a = 10;
+CREATE TABLE test_table(a int, b int);
+INSERT INTO test_table VALUES(20, 20);
+-- no warning
+SELECT a;
+ a
+----
+ 10
+(1 row)
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a | b
+----+----
+ 20 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a) FROM test_table;
+ a
+----
+ 10
+(1 row)
+
+ALTER TABLE test_table DROP COLUMN a;
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is not used inside variable fence
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+DROP SCHEMA testvar;
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 68be415bf26..c5420183d94 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1360,3 +1360,44 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
+
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+
+CREATE SCHEMA testvar;
+
+SET search_path TO 'testvar';
+
+CREATE VARIABLE a AS int;
+LET a = 10;
+
+CREATE TABLE test_table(a int, b int);
+
+INSERT INTO test_table VALUES(20, 20);
+
+-- no warning
+SELECT a;
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a) FROM test_table;
+
+ALTER TABLE test_table DROP COLUMN a;
+
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+
+DROP SCHEMA testvar;
+
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
--
2.49.0
[text/x-patch] v20250402-0003-function-pg_session_variables-for-cleaning-tests.patch (4.4K, ../../CAFj8pRAK_8ym1J=SAdin-vtL0PAachXgjWgU3QrhzinRdBX2sw@mail.gmail.com/8-v20250402-0003-function-pg_session_variables-for-cleaning-tests.patch)
download | inline diff:
From 26e231b061286a4c73c7def2871ae480bd5e46a9 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 20:01:56 +0100
Subject: [PATCH 03/21] function pg_session_variables for cleaning tests
This is a function designed for testing and debugging. It returns the
content of sessionvars as-is, and can therefore display entries about
session variables that were dropped but for which this backend didn't
process the shared invalidations yet.
---
src/backend/commands/session_variable.c | 92 +++++++++++++++++++++++++
src/include/catalog/pg_proc.dat | 8 +++
2 files changed, 100 insertions(+)
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index d2891a1dcb7..fa16f47072e 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -527,3 +527,95 @@ ExecuteLetStmt(ParseState *pstate,
PopActiveSnapshot();
}
+
+/*
+ * pg_session_variables - designed for testing
+ *
+ * This is a function designed for testing and debugging. It returns the
+ * content of session variables as-is, and can therefore display data about
+ * session variables that were dropped, but for which this backend didn't
+ * process the shared invalidations yet.
+ */
+Datum
+pg_session_variables(PG_FUNCTION_ARGS)
+{
+#define NUM_PG_SESSION_VARIABLES_ATTS 8
+
+ InitMaterializedSRF(fcinfo, 0);
+
+ if (sessionvars)
+ {
+ ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ Datum values[NUM_PG_SESSION_VARIABLES_ATTS];
+ bool nulls[NUM_PG_SESSION_VARIABLES_ATTS];
+ HeapTuple tp;
+ bool var_is_valid = false;
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, 0, sizeof(nulls));
+
+ values[0] = ObjectIdGetDatum(svar->varid);
+ values[3] = ObjectIdGetDatum(svar->typid);
+
+ /*
+ * It is possible that the variable has been dropped from the
+ * catalog, but not yet purged from the hash table.
+ */
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ Form_pg_variable varform = (Form_pg_variable) GETSTRUCT(tp);
+
+ /*
+ * It is also possible that a variable has been dropped and
+ * someone created a new variable with the same object ID. Use
+ * the catalog information only if that is not the case.
+ */
+ if (svar->create_lsn == varform->varcreate_lsn)
+ {
+ values[1] = CStringGetTextDatum(
+ get_namespace_name(varform->varnamespace));
+
+ values[2] = CStringGetTextDatum(NameStr(varform->varname));
+ values[4] = CStringGetTextDatum(format_type_be(svar->typid));
+ values[5] = BoolGetDatum(false);
+
+ values[6] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_SELECT) == ACLCHECK_OK);
+
+ values[7] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_UPDATE) == ACLCHECK_OK);
+
+ var_is_valid = true;
+ }
+
+ ReleaseSysCache(tp);
+ }
+
+ /* if there is no matching catalog entry, return null values */
+ if (!var_is_valid)
+ {
+ nulls[1] = true;
+ nulls[2] = true;
+ nulls[4] = true;
+ values[5] = BoolGetDatum(true);
+ nulls[6] = true;
+ nulls[7] = true;
+ }
+
+ tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
+ }
+ }
+
+ return (Datum) 0;
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa29734138f..71b4c40ef6f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -12537,4 +12537,12 @@
proargnames => '{pid,io_id,io_generation,state,operation,off,length,target,handle_data_len,raw_result,result,target_desc,f_sync,f_localmem,f_buffered}',
prosrc => 'pg_get_aios' },
+# Session variables support
+{ oid => '8488', descr => 'list of used session variables',
+ proname => 'pg_session_variables', prorows => '1000', proretset => 't',
+ provolatile => 's', proparallel => 'r', prorettype => 'record',
+ proargtypes => '', proallargtypes => '{oid,text,text,oid,text,bool,bool,bool}',
+ proargmodes => '{o,o,o,o,o,o,o,o}',
+ proargnames => '{varid,schema,name,typid,typname,removed,can_select,can_update}',
+ prosrc => 'pg_session_variables' },
]
--
2.49.0
[text/x-patch] v20250402-0002-Storage-for-session-variables-and-SQL-interface.patch (159.6K, ../../CAFj8pRAK_8ym1J=SAdin-vtL0PAachXgjWgU3QrhzinRdBX2sw@mail.gmail.com/9-v20250402-0002-Storage-for-session-variables-and-SQL-interface.patch)
download | inline diff:
From ae2296ed3ae7a87ee4383b812da903acf4cc251a Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Thu, 6 Jul 2023 08:29:21 +0200
Subject: [PATCH 02/21] Storage for session variables and SQL interface
Session variables are stored in session memory in a dedicated hash table.
They are set by the LET command and read by the SELECT command.
The access rights should be checked.
The identifiers of session variables should always be shadowed by possible
column identifiers: we don't want to break an application by creating some
badly named session variable.
The limits of this patch (solved by other patches):
- session variables block parallel execution
- session variables blocks simple expression evaluation (in plpgsql)
- SQL functions with session variables are not inlined
- CALL statement is not supported (usage of direct access to express executor)
- EXECUTE statement is not supported (usage of direct access to express executor)
- memory used by dropped session variables is not released
Implementations of EXPLAIN LET and PREPARE LET statements
are in separate patches (for better readability)
---
doc/src/sgml/catalogs.sgml | 13 +
doc/src/sgml/ddl.sgml | 61 +
doc/src/sgml/func.sgml | 4 +-
doc/src/sgml/glossary.sgml | 5 +-
doc/src/sgml/parallel.sgml | 6 +
doc/src/sgml/plpgsql.sgml | 14 +
doc/src/sgml/ref/allfiles.sgml | 1 +
doc/src/sgml/ref/alter_variable.sgml | 1 +
doc/src/sgml/ref/create_variable.sgml | 5 +-
doc/src/sgml/ref/drop_variable.sgml | 1 +
doc/src/sgml/ref/let.sgml | 96 ++
doc/src/sgml/reference.sgml | 1 +
src/backend/catalog/dependency.c | 5 +
src/backend/catalog/namespace.c | 289 ++++
src/backend/catalog/pg_variable.c | 2 +
src/backend/commands/Makefile | 1 +
src/backend/commands/meson.build | 1 +
src/backend/commands/prepare.c | 10 +
src/backend/commands/session_variable.c | 529 +++++++
src/backend/executor/Makefile | 1 +
src/backend/executor/execExpr.c | 32 +
src/backend/executor/execMain.c | 66 +
src/backend/executor/meson.build | 1 +
src/backend/executor/svariableReceiver.c | 172 +++
src/backend/nodes/nodeFuncs.c | 10 +
src/backend/optimizer/plan/planner.c | 36 +
src/backend/optimizer/plan/setrefs.c | 156 ++-
src/backend/optimizer/prep/prepjointree.c | 3 +
src/backend/optimizer/util/clauses.c | 33 +-
src/backend/parser/analyze.c | 272 +++-
src/backend/parser/gram.y | 39 +-
src/backend/parser/parse_agg.c | 9 +
src/backend/parser/parse_expr.c | 223 ++-
src/backend/parser/parse_func.c | 2 +
src/backend/parser/parse_merge.c | 1 +
src/backend/tcop/dest.c | 7 +
src/backend/tcop/utility.c | 16 +
src/backend/utils/adt/ruleutils.c | 46 +
src/backend/utils/cache/plancache.c | 41 +-
src/backend/utils/fmgr/fmgr.c | 10 +-
src/bin/psql/tab-complete.in.c | 12 +-
src/include/catalog/namespace.h | 1 +
src/include/catalog/pg_variable.h | 9 +
src/include/commands/session_variable.h | 30 +
src/include/executor/svariableReceiver.h | 22 +
src/include/nodes/execnodes.h | 14 +
src/include/nodes/parsenodes.h | 17 +
src/include/nodes/pathnodes.h | 14 +
src/include/nodes/plannodes.h | 9 +
src/include/nodes/primnodes.h | 14 +
src/include/optimizer/planmain.h | 2 +
src/include/parser/kwlist.h | 1 +
src/include/parser/parse_node.h | 3 +
src/include/tcop/cmdtaglist.h | 1 +
src/include/tcop/dest.h | 1 +
src/pl/plpgsql/src/pl_exec.c | 3 +-
.../regress/expected/session_variables.out | 1232 +++++++++++++++++
src/test/regress/sql/session_variables.sql | 883 ++++++++++++
src/tools/pgindent/typedefs.list | 5 +
59 files changed, 4467 insertions(+), 27 deletions(-)
create mode 100644 doc/src/sgml/ref/let.sgml
create mode 100644 src/backend/commands/session_variable.c
create mode 100644 src/backend/executor/svariableReceiver.c
create mode 100644 src/include/commands/session_variable.h
create mode 100644 src/include/executor/svariableReceiver.h
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 8321b453e2c..125d755246a 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9831,6 +9831,19 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcreate_lsn</structfield> <type>pg_lsn</type>
+ </para>
+ <para>
+ LSN of the transaction where the variable was created.
+ <structfield>varcreate_lsn</structfield> and
+ <structfield>oid</structfield> together form the all-time unique
+ identifier (<structfield>oid</structfield> alone is not enough, since
+ object identifiers can get reused).
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>varname</structfield> <type>name</type>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 6a493c2f561..fce5e72bbf6 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5388,6 +5388,67 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
The session variable holds value in session memory. This value is private
to each session and is released when the session ends.
</para>
+
+ <para>
+ The value of a session variable is set with the SQL statement
+ <command>LET</command>. The value of a session variable can be retrieved
+ with the SQL statement <command>SELECT</command>.
+<programlisting>
+CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
+</programlisting>
+
+ or
+
+<programlisting>
+CREATE VARIABLE public.current_user_id AS integer;
+GRANT SELECT ON VARIABLE public.current_user_id TO PUBLIC;
+LET current_user_id = (SELECT id FROM users WHERE usename = session_user);
+SELECT current_user_id;
+</programlisting>
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a variable's value returns a <literal>NULL</literal>, unless its value has
+ been set to something else in the current session using the
+ <command>LET</command> command. Session variables are not transactional:
+ any changes made to the value of a session variable in a transaction won't
+ be undone if the transaction is rolled back (just like variables in
+ procedural languages). Session variables themselves are persistent, but
+ their values are neither persistent nor shared (like the content of
+ temporary tables).
+ </para>
+
+ <para>
+ Inside a query or an expression, a session variable can be
+ <quote>shadowed</quote> by a column with the same name. Similarly, the
+ name of a function or procedure argument or a PL/pgSQL variable (see
+ <xref linkend="plpgsql-declarations"/>) can shadow a session variable
+ in the routine's body. Such collisions of identifiers can be resolved
+ by using qualified identifiers: Session variables can be qualified with
+ the schema name, columns can use table aliases, routine variables can use
+ block labels, and routine arguments can use the routine name.
+<programlisting>
+CREATE VARIABLE name AS text;
+LET name = 'John';
+
+CREATE TABLE foo(name text);
+INSERT INTO foo VALUES('Alice');
+
+-- variable name is shadowed
+SELECT name FROM foo;
+</programlisting>
+
+ which returns:
+
+<programlisting>
+ name
+-------
+ Alice
+</programlisting>
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 010f7892fe0..37cf0c6435c 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25847,8 +25847,8 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
't' for <literal>TABLESPACE</literal>,
'F' for <literal>FOREIGN DATA WRAPPER</literal>,
'S' for <literal>FOREIGN SERVER</literal>,
- or
- 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal>.
+ 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal> or
+ 'V' for <literal>SESSION VARIABLE</literal>.
</para></entry>
</row>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index 83b13f98f28..2d13dcea4ef 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1714,8 +1714,9 @@
<para>
A persistent database object that holds a value in session memory. This
value is private to each session and is released when the session ends.
- Read or write access to session variables is controlled by privileges,
- similar to other database objects.
+ The default value of the session variable is null. Read or write access
+ to session variables is controlled by privileges, similar to other database
+ objects.
</para>
<para>
For more information, see <xref linkend="ddl-session-variables"/>.
diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index 1ce9abf86f5..683dede6adc 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -515,6 +515,12 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
Plan nodes that reference a correlated <literal>SubPlan</literal>.
</para>
</listitem>
+
+ <listitem>
+ <para>
+ Plan nodes that use a session variable.
+ </para>
+ </listitem>
</itemizedlist>
<sect2 id="parallel-labeling">
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index e937491e6b8..1e4c43b8b61 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -6036,6 +6036,20 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE;
</programlisting>
</para>
</sect3>
+
+ <sect3 id="plpgsql-porting-package-variables">
+ <title><command>Packages and package variables</command></title>
+
+ <para>
+ The <application>PL/pgSQL</application> language has no packages, and
+ therefore no package variables or package constants.
+ You can consider translating an Oracle package into a schema in
+ <productname>PostgreSQL</productname>. Package functions and procedures
+ would then become functions and procedures in that schema, and package
+ variables could be translated to session variables in that schema.
+ (see <xref linkend="ddl-session-variables"/>).
+ </para>
+ </sect3>
</sect2>
<sect2 id="plpgsql-porting-appendix">
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index 2f67de3e21b..cc3bd5ab540 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -158,6 +158,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY grant SYSTEM "grant.sgml">
<!ENTITY importForeignSchema SYSTEM "import_foreign_schema.sgml">
<!ENTITY insert SYSTEM "insert.sgml">
+<!ENTITY let SYSTEM "let.sgml">
<!ENTITY listen SYSTEM "listen.sgml">
<!ENTITY load SYSTEM "load.sgml">
<!ENTITY lock SYSTEM "lock.sgml">
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
index 96d2586423e..221a699469b 100644
--- a/doc/src/sgml/ref/alter_variable.sgml
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -173,6 +173,7 @@ ALTER VARIABLE boo SET SCHEMA private;
<simplelist type="inline">
<member><xref linkend="sql-createvariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
</refentry>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index 6e988f2e472..cd9ff63975a 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -120,9 +120,11 @@ CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceab
<title>Examples</title>
<para>
- Create an date session variable <literal>var1</literal>:
+ Create a session variable <literal>var1</literal> of data type date:
<programlisting>
CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
</programlisting>
</para>
@@ -143,6 +145,7 @@ CREATE VARIABLE var1 AS date;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
index 5bdb3560f0b..67988b5fcd8 100644
--- a/doc/src/sgml/ref/drop_variable.sgml
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -111,6 +111,7 @@ DROP VARIABLE var1;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/let.sgml b/doc/src/sgml/ref/let.sgml
new file mode 100644
index 00000000000..00f9bea91fe
--- /dev/null
+++ b/doc/src/sgml/ref/let.sgml
@@ -0,0 +1,96 @@
+<!--
+doc/src/sgml/ref/let.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-let">
+ <indexterm zone="sql-let">
+ <primary>LET</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>changing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>LET</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>LET</refname>
+ <refpurpose>change a session variable's value</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+LET <replaceable class="parameter">session_variable</replaceable> = <replaceable class="parameter">sql_expression</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>LET</command> command assigns a value to the specified session
+ variable.
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">session_variable</replaceable></term>
+ <listitem>
+ <para>
+ The name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">sql_expression</replaceable></term>
+ <listitem>
+ <para>
+ An arbitrary SQL expression. The result must be of a data type that can
+ be cast to the type of the session variable in an assignment.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+<programlisting>
+CREATE VARIABLE myvar AS integer;
+LET myvar = 10;
+LET myvar = (SELECT sum(val) FROM tab);
+</programlisting>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>LET</command> is a <productname>PostgreSQL</productname>
+ extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index 25578f3946c..13e4adc5df3 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -186,6 +186,7 @@
&grant;
&importForeignSchema;
&insert;
+ &let;
&listen;
&load;
&lock;
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 9e0f648b74f..90c9e8bb254 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1864,6 +1864,11 @@ find_expr_references_walker(Node *node,
{
Param *param = (Param *) node;
+ /* a variable parameter depends on the session variable */
+ if (param->paramkind == PARAM_VARIABLE)
+ add_object_address(VariableRelationId, param->paramvarid, 0,
+ context->addrs);
+
/* A parameter must depend on the parameter's datatype */
add_object_address(TypeRelationId, param->paramtype, 0,
context->addrs);
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 4307cad15c7..beafee2a341 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -3497,6 +3497,295 @@ NamesFromList(List *names)
return result;
}
+/* -----
+ * IdentifyVariable - try to find a variable from a list of identifiers
+ *
+ * Returns the OID of the variable found, or InvalidOid.
+ *
+ * "names" is a list of up to four identifiers; possible meanings are:
+ * - variable (searched on the search_path)
+ * - schema.variable
+ * - variable.attribute (searched on the search_path)
+ * - schema.variable.attribute
+ * - database.schema.variable
+ * - database.schema.variable.attribute
+ *
+ * If there is more than one way to identify a variable, "not_unique" will be
+ * set to true.
+ *
+ * Unless "noerror" is true, an error is raised if there are more than four
+ * identifiers in the list, or if the named database is not the current one.
+ * This is useful if we want to identify a shadowed variable.
+ *
+ * If an attribute is identified, it is stored in "attrname", otherwise the
+ * parameter is set to NULL.
+ *
+ * The identified session variable will be locked with an AccessShareLock.
+ * -----
+ */
+Oid
+IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror)
+{
+ Oid varid = InvalidOid;
+ Oid old_varid = InvalidOid;
+ uint64 inval_count;
+ bool retry = false;
+
+ /*
+ * DDL operations can change the results of a name lookup. Since all such
+ * operations will generate invalidation messages, we keep track of
+ * whether any such messages show up while we're performing the operation,
+ * and retry until either (1) no more invalidation messages show up or (2)
+ * the answer doesn't change.
+ */
+ for (;;)
+ {
+ Node *field1 = NULL;
+ Node *field2 = NULL;
+ Node *field3 = NULL;
+ Node *field4 = NULL;
+ char *a = NULL;
+ char *b = NULL;
+ char *c = NULL;
+ char *d = NULL;
+ Oid varoid_without_attr = InvalidOid;
+ Oid varoid_with_attr = InvalidOid;
+
+ *not_unique = false;
+ *attrname = NULL;
+ varid = InvalidOid;
+
+ inval_count = SharedInvalidMessageCounter;
+
+ switch (list_length(names))
+ {
+ case 1:
+ field1 = linitial(names);
+
+ Assert(IsA(field1, String));
+
+ varid = LookupVariable(NULL, strVal(field1), true);
+ break;
+
+ case 2:
+ field1 = linitial(names);
+ field2 = lsecond(names);
+
+ Assert(IsA(field1, String));
+ a = strVal(field1);
+
+ if (IsA(field2, String))
+ {
+ /* when both fields are of string type */
+ b = strVal(field2);
+
+ /*
+ * a.b can mean "schema"."variable" or
+ * "variable"."attribute". Check both variants, and
+ * returns InvalidOid with not_unique flag, when both
+ * interpretations are possible.
+ */
+ varoid_without_attr = LookupVariable(a, b, true);
+ varoid_with_attr = LookupVariable(NULL, a, true);
+ }
+ else
+ {
+ /* the last field of list can be star too */
+ Assert(IsA(field2, A_Star));
+
+ /*
+ * The syntax ident.* is used only by relation aliases,
+ * and then this identifier cannot be a reference to
+ * session variable.
+ */
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = b;
+ varid = varoid_with_attr;
+ }
+ break;
+
+ case 3:
+ {
+ bool field1_is_catalog = false;
+
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+
+ if (IsA(field3, String))
+ {
+ c = strVal(field3);
+
+ /*
+ * a.b.c can mean catalog.schema.variable or
+ * schema.variable.attribute.
+ *
+ * Check both variants, and set not_unique flag, when
+ * both interpretations are possible.
+ *
+ * When third node is star, only possible
+ * interpretation is schema.variable.*, but this
+ * pattern is not supported now.
+ */
+ varoid_with_attr = LookupVariable(a, b, true);
+
+ /*
+ * check pattern catalog.schema.variable only when
+ * there is possibility to success.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) == 0)
+ {
+ field1_is_catalog = true;
+ varoid_without_attr = LookupVariable(b, c, true);
+ }
+ }
+ else
+ {
+ Assert(IsA(field3, A_Star));
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = c;
+ varid = varoid_with_attr;
+ }
+
+ /*
+ * When we didn't find variable, we can (when it is
+ * allowed) raise cross-database reference error.
+ */
+ if (!OidIsValid(varid) && !noerror && !field1_is_catalog)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+ break;
+
+ case 4:
+ {
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+ field4 = lfourth(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+ Assert(IsA(field3, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+ c = strVal(field3);
+
+ /*
+ * In this case, "a" is used as catalog name - check it.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) != 0)
+ {
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+
+ if (IsA(field4, String))
+ {
+ d = strVal(field4);
+ }
+ else
+ {
+ Assert(IsA(field4, A_Star));
+ return InvalidOid;
+ }
+
+ *attrname = d;
+ varid = LookupVariable(b, c, true);
+ }
+ break;
+
+ default:
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper qualified name (too many dotted names): %s",
+ NameListToString(names))));
+ return InvalidOid;
+ }
+
+ /*
+ * If, upon retry, we get back the same OID we did last time, then the
+ * invalidation messages we processed did not change the final answer.
+ * So we're done.
+ *
+ * If we got a different OID, we've locked the variable that used to
+ * have this name rather than the one that does now. So release the
+ * lock.
+ */
+ if (retry)
+ {
+ if (old_varid == varid)
+ break;
+
+ if (OidIsValid(old_varid))
+ UnlockDatabaseObject(VariableRelationId, old_varid, 0, AccessShareLock);
+ }
+
+ /*
+ * Lock the variable. This will also accept any pending invalidation
+ * messages. If we got back InvalidOid, indicating not found, then
+ * there's nothing to lock, but we accept invalidation messages
+ * anyway, to flush any negative catcache entries that may be
+ * lingering.
+ */
+ if (!OidIsValid(varid))
+ AcceptInvalidationMessages();
+ else
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ /*
+ * If no invalidation message were processed, we're done!
+ */
+ if (inval_count == SharedInvalidMessageCounter)
+ break;
+
+ retry = true;
+ old_varid = varid;
+ varid = InvalidOid;
+ }
+
+ return varid;
+}
+
/*
* DeconstructQualifiedName
* Given a possibly-qualified name expressed as a list of String nodes,
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 29d967a2d5b..bb445e9434b 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -26,6 +26,7 @@
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
+#include "utils/pg_lsn.h"
#include "utils/syscache.h"
static ObjectAddress create_variable(const char *varName,
@@ -101,6 +102,7 @@ create_variable(const char *varName,
varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varcreate_lsn - 1] = LSNGetDatum(GetXLogInsertRecPtr());
values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile
index cb2fbdc7c60..aee40e7bd59 100644
--- a/src/backend/commands/Makefile
+++ b/src/backend/commands/Makefile
@@ -53,6 +53,7 @@ OBJS = \
schemacmds.o \
seclabel.o \
sequence.o \
+ session_variable.o \
statscmds.o \
subscriptioncmds.o \
tablecmds.o \
diff --git a/src/backend/commands/meson.build b/src/backend/commands/meson.build
index dd4cde41d32..101c8d75dd1 100644
--- a/src/backend/commands/meson.build
+++ b/src/backend/commands/meson.build
@@ -41,6 +41,7 @@ backend_sources += files(
'schemacmds.c',
'seclabel.c',
'sequence.c',
+ 'session_variable.c',
'statscmds.c',
'subscriptioncmds.c',
'tablecmds.c',
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index bf7d2b2309f..56b3d8cb91d 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -342,6 +342,16 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
i++;
}
+ /*
+ * The arguments of EXECUTE are evaluated by a direct expression
+ * executor call. This mode doesn't support session variables yet.
+ * It will be enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
/* Prepare the expressions for execution */
exprstates = ExecPrepareExprList(params, estate);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
new file mode 100644
index 00000000000..d2891a1dcb7
--- /dev/null
+++ b/src/backend/commands/session_variable.c
@@ -0,0 +1,529 @@
+/*-------------------------------------------------------------------------
+ *
+ * session_variable.c
+ * session variable creation/manipulation commands
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/commands/session_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "rewrite/rewriteHandler.h"
+#include "storage/lmgr.h"
+#include "storage/proc.h"
+#include "tcop/tcopprot.h"
+#include "utils/builtins.h"
+#include "utils/datum.h"
+#include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/snapmgr.h"
+#include "utils/syscache.h"
+
+/*
+ * The values of session variables are stored in the backend's private memory
+ * in the dedicated memory context SVariableMemoryContext in binary format.
+ * They are stored in the "sessionvars" hash table, whose key is the OID of the
+ * variable. However, the OID is not good enough to identify a session
+ * variable: concurrent sessions could drop the session variable and create a
+ * new one, which could be assigned the same OID. To ensure that the values
+ * stored in memory and the catalog definition match, we also keep track of
+ * the "create_lsn". Before any access to the variable values, we need to
+ * check if the LSN stored in memory matches the LSN in the catalog. If there
+ * is a mismatch between the LSNs, or if the OID is not present in pg_variable
+ * at all, the value stored in memory is released.
+ */
+typedef struct SVariableData
+{
+ Oid varid; /* pg_variable OID of the variable (hash key) */
+ XLogRecPtr create_lsn;
+
+ bool isnull;
+ Datum value;
+
+ Oid typid;
+ int16 typlen;
+ bool typbyval;
+
+ bool is_domain;
+
+ /*
+ * domain_check_extra holds cached domain metadata. This "extra" is
+ * usually stored in fn_mcxt. We do not have access to that memory context
+ * for session variables, but we can use TopTransactionContext instead.
+ * A fresh value is forced when we detect we are in a different transaction
+ * (the local transaction ID differs from domain_check_extra_lxid).
+ */
+ void *domain_check_extra;
+ LocalTransactionId domain_check_extra_lxid;
+
+ /*
+ * Stored value and type description can be outdated when we receive a
+ * sinval message. We then have to check if the stored data are still
+ * trustworthy.
+ */
+ bool is_valid;
+
+ uint32 hashvalue; /* used for pairing sinval message */
+} SVariableData;
+
+typedef SVariableData *SVariable;
+
+static HTAB *sessionvars = NULL; /* hash table for session variables */
+
+static MemoryContext SVariableMemoryContext = NULL;
+
+/*
+ * Callback function for session variable invalidation.
+ */
+static void
+pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
+
+ Assert(sessionvars);
+
+ /*
+ * If the hashvalue is not specified, we have to recheck all currently
+ * used session variables. Since we can't tell the exact session variable
+ * from its hashvalue, we have to iterate over all items in the hash bucket.
+ */
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (hashvalue == 0 || svar->hashvalue == hashvalue)
+ {
+ svar->is_valid = false;
+ }
+ }
+}
+
+/*
+ * Release stored value, free memory
+ */
+static void
+free_session_variable_value(SVariable svar)
+{
+ /* clean the current value */
+ if (!svar->isnull)
+ {
+ if (!svar->typbyval)
+ pfree(DatumGetPointer(svar->value));
+
+ svar->isnull = true;
+ }
+
+ svar->value = (Datum) 0;
+}
+
+/*
+ * Returns true when the entry in pg_variable is consistent with the given
+ * session variable.
+ */
+static bool
+is_session_variable_valid(SVariable svar)
+{
+ HeapTuple tp;
+ bool result = false;
+
+ Assert(OidIsValid(svar->varid));
+
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ /*
+ * The OID alone is not enough as an unique identifier, because OID
+ * values get recycled, and a new session variable could have got
+ * the same OID. We do a second check against the 64-bit LSN when
+ * the variable was created.
+ */
+ if (svar->create_lsn == ((Form_pg_variable) GETSTRUCT(tp))->varcreate_lsn)
+ result = true;
+
+ ReleaseSysCache(tp);
+ }
+
+ return result;
+}
+
+/*
+ * Initialize attributes cached in "svar"
+ */
+static void
+setup_session_variable(SVariable svar, Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ Assert(OidIsValid(varid));
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ svar->varid = varid;
+ svar->create_lsn = varform->varcreate_lsn;
+
+ svar->typid = varform->vartype;
+
+ get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval);
+
+ svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
+ svar->domain_check_extra = NULL;
+ svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+
+ svar->isnull = true;
+ svar->value = (Datum) 0;
+
+ svar->is_valid = true;
+
+ svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ ReleaseSysCache(tup);
+}
+
+/*
+ * Assign a new value to the session variable. It is copied to
+ * SVariableMemoryContext if necessary.
+ *
+ * If any error happens, the existing value won't be modified.
+ */
+static void
+set_session_variable(SVariable svar, Datum value, bool isnull)
+{
+ Datum newval;
+ SVariableData locsvar,
+ *_svar;
+
+ Assert(svar);
+ Assert(!isnull || value == (Datum) 0);
+
+ /*
+ * Use typbyval, typbylen from session variable only when they are
+ * trustworthy (the invalidation message was not accepted for this
+ * variable). If the variable might be invalid, force setup.
+ *
+ * Do not overwrite the passed session variable until we can be certain
+ * that no error can be thrown.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(&locsvar, svar->varid);
+ _svar = &locsvar;
+ }
+ else
+ _svar = svar;
+
+ if (!isnull)
+ {
+ MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
+
+ newval = datumCopy(value, _svar->typbyval, _svar->typlen);
+
+ MemoryContextSwitchTo(oldcxt);
+ }
+ else
+ newval = value;
+
+ free_session_variable_value(svar);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ svar->varid);
+
+ /* no more error expected, so we can overwrite the old variable now */
+ if (svar != _svar)
+ memcpy(svar, _svar, sizeof(SVariableData));
+
+ svar->value = newval;
+ svar->isnull = isnull;
+}
+
+/*
+ * Create the hash table for storing session variables.
+ */
+static void
+create_sessionvars_hashtables(void)
+{
+ HASHCTL vars_ctl;
+
+ Assert(!sessionvars);
+
+ if (!SVariableMemoryContext)
+ {
+ /* read sinval messages */
+ CacheRegisterSyscacheCallback(VARIABLEOID,
+ pg_variable_cache_callback,
+ (Datum) 0);
+
+ /* we need our own long-lived memory context */
+ SVariableMemoryContext =
+ AllocSetContextCreate(TopMemoryContext,
+ "session variables",
+ ALLOCSET_START_SMALL_SIZES);
+ }
+
+ memset(&vars_ctl, 0, sizeof(vars_ctl));
+ vars_ctl.keysize = sizeof(Oid);
+ vars_ctl.entrysize = sizeof(SVariableData);
+ vars_ctl.hcxt = SVariableMemoryContext;
+
+ sessionvars = hash_create("Session variables", 64, &vars_ctl,
+ HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+}
+
+/*
+ * Search a session variable in the hash table given its OID. If it
+ * doesn't exist, then insert it there.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the
+ * session variable until the end of the transaction.
+ */
+static SVariable
+get_session_variable(Oid varid)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect the used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (found)
+ {
+ if (!svar->is_valid)
+ {
+ /*
+ * If there was an invalidation message, the variable might still be
+ * valid, but we have to check with the system catalog.
+ */
+ if (is_session_variable_valid(svar))
+ svar->is_valid = true;
+ else
+ /* if the value cannot be validated, we have to discard it */
+ free_session_variable_value(svar);
+ }
+ }
+ else
+ svar->is_valid = false;
+
+ /*
+ * Force setup for not yet initialized variables or variables that cannot
+ * be validated.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ varid);
+ }
+
+ /* ensure the returned data is still of the correct domain */
+ if (svar->is_domain)
+ {
+ /*
+ * Store "extra" for domain_check() in TopTransactionContext. When we
+ * are in a new transaction, domain_check_extra cache is not valid any
+ * more.
+ */
+ if (svar->domain_check_extra_lxid != MyProc->vxid.lxid)
+ svar->domain_check_extra = NULL;
+
+ domain_check(svar->value, svar->isnull,
+ svar->typid, &svar->domain_check_extra,
+ TopTransactionContext);
+
+ svar->domain_check_extra_lxid = MyProc->vxid.lxid;
+ }
+
+ return svar;
+}
+
+/*
+ * Store the given value in a session variable in the cache.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the session
+ * variable until the end of the transaction.
+ */
+void
+SetSessionVariable(Oid varid, Datum value, bool isNull)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (!found)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ varid);
+ }
+
+ /* if this fails, it won't change the stored value */
+ set_session_variable(svar, value, isNull);
+}
+
+/*
+ * Returns a copy of the value stored in a variable.
+ */
+static inline Datum
+copy_session_variable_value(SVariable svar, bool *isNull)
+{
+ Datum value;
+
+ /* force copy of non NULL value */
+ if (!svar->isnull)
+ {
+ value = datumCopy(svar->value, svar->typbyval, svar->typlen);
+ *isNull = false;
+ }
+ else
+ {
+ value = (Datum) 0;
+ *isNull = true;
+ }
+
+ return value;
+}
+
+/*
+ * Returns a copy of the value of the session variable (in the current memory
+ * context). The caller is responsible for permission checks.
+ */
+Datum
+GetSessionVariable(Oid varid, bool *isNull)
+{
+ SVariable svar;
+
+ svar = get_session_variable(varid);
+
+ /*
+ * Although "svar" is freshly validated in this point, svar->is_valid can
+ * be false, if an invalidation message was processed during the domain check.
+ * But the variable and all its dependencies are locked now, so we don't need
+ * to repeat the validation.
+ */
+ return copy_session_variable_value(svar, isNull);
+}
+
+/*
+ * Assign the result of the evaluated expression to the session variable
+ */
+void
+ExecuteLetStmt(ParseState *pstate,
+ LetStmt *stmt,
+ ParamListInfo params,
+ QueryEnvironment *queryEnv,
+ QueryCompletion *qc)
+{
+ Query *query = castNode(Query, stmt->query);
+ List *rewritten;
+ DestReceiver *dest;
+ AclResult aclresult;
+ PlannedStmt *plan;
+ QueryDesc *queryDesc;
+ Oid varid = query->resultVariable;
+
+ Assert(OidIsValid(varid));
+
+ /* do we have permission to write to the session variable? */
+ aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid));
+
+ /* create a dest receiver for LET */
+ dest = CreateVariableDestReceiver(varid);
+
+ /* run the query rewriter */
+ query = copyObject(query);
+
+ rewritten = QueryRewrite(query);
+
+ Assert(list_length(rewritten) == 1);
+
+ query = linitial_node(Query, rewritten);
+ Assert(query->commandType == CMD_SELECT);
+
+ /* plan the query */
+ plan = pg_plan_query(query, pstate->p_sourcetext,
+ CURSOR_OPT_PARALLEL_OK, params);
+
+ /*
+ * Use a snapshot with an updated command ID to ensure this query sees the
+ * results of any previously executed queries. (This could only matter if
+ * the planner executed an allegedly-stable function that changed the
+ * database contents, but let's do it anyway to be parallel to the EXPLAIN
+ * code path.)
+ */
+ PushCopiedSnapshot(GetActiveSnapshot());
+ UpdateActiveSnapshotCommandId();
+
+ /* create a QueryDesc, redirecting output to our tuple receiver */
+ queryDesc = CreateQueryDesc(plan, NULL, pstate->p_sourcetext,
+ GetActiveSnapshot(), InvalidSnapshot,
+ dest, params, queryEnv, 0);
+
+ /* call ExecutorStart to prepare the plan for execution */
+ ExecutorStart(queryDesc, 0);
+
+ /*
+ * Run the plan to completion. The result should be only one row. To
+ * check if there are too many result rows, we try to fetch two.
+ */
+ ExecutorRun(queryDesc, ForwardScanDirection, 2L);
+
+ /* save the rowcount if we're given a QueryCompletion to fill */
+ if (qc)
+ SetQueryCompletion(qc, CMDTAG_LET, queryDesc->estate->es_processed);
+
+ /* and clean up */
+ ExecutorFinish(queryDesc);
+ ExecutorEnd(queryDesc);
+
+ FreeQueryDesc(queryDesc);
+
+ PopActiveSnapshot();
+}
diff --git a/src/backend/executor/Makefile b/src/backend/executor/Makefile
index 11118d0ce02..71248a34f26 100644
--- a/src/backend/executor/Makefile
+++ b/src/backend/executor/Makefile
@@ -76,6 +76,7 @@ OBJS = \
nodeWindowAgg.o \
nodeWorktablescan.o \
spi.o \
+ svariableReceiver.o \
tqueue.o \
tstoreReceiver.o
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index f1569879b52..e4e9de335b5 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -1041,6 +1041,38 @@ ExecInitExprRec(Expr *node, ExprState *state,
scratch.d.param.paramtype = param->paramtype;
ExprEvalPushStep(state, &scratch);
break;
+
+ case PARAM_VARIABLE:
+ {
+ int es_num_session_variables = 0;
+ SessionVariableValue *es_session_variables = NULL;
+ SessionVariableValue *var;
+
+ if (state->parent && state->parent->state)
+ {
+ es_session_variables = state->parent->state->es_session_variables;
+ es_num_session_variables = state->parent->state->es_num_session_variables;
+ }
+
+ Assert(es_session_variables);
+
+ /* parameter sanity checks */
+ if (param->paramid >= es_num_session_variables)
+ elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
+
+ var = &es_session_variables[param->paramid];
+
+ /*
+ * In this case, pass the value like a
+ * constant.
+ */
+ scratch.opcode = EEOP_CONST;
+ scratch.d.constval.value = var->value;
+ scratch.d.constval.isnull = var->isnull;
+ ExprEvalPushStep(state, &scratch);
+ }
+ break;
+
case PARAM_EXTERN:
/*
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 2da848970be..3161ac9f5f7 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -43,7 +43,9 @@
#include "access/xact.h"
#include "catalog/namespace.h"
#include "catalog/partition.h"
+#include "catalog/pg_variable.h"
#include "commands/matview.h"
+#include "commands/session_variable.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/execPartition.h"
@@ -206,6 +208,70 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
Assert(queryDesc->sourceText != NULL);
estate->es_sourceText = queryDesc->sourceText;
+ /*
+ * The executor doesn't work with session variables directly. Values of
+ * related session variables are copied to a dedicated array, and this array
+ * is passed to the executor. This array is stable "snapshot" of values of
+ * used session variables. There are three benefits of this strategy:
+ *
+ * - consistency with external parameters and plpgsql variables,
+ *
+ * - session variables can be parallel safe,
+ *
+ * - we don't need make fresh copy for any read of session variable
+ * (this is necessary because the internally the session variable can
+ * be changed inside query execution time, and then a reference to
+ * previously returned value can be corrupted).
+ */
+ if (queryDesc->plannedstmt->sessionVariables)
+ {
+ int nSessionVariables;
+ int i = 0;
+
+ /*
+ * In this case, the query uses session variables, but we have to
+ * prepare the array with passed values (of used session variables)
+ * first.
+ */
+ Assert(!IsParallelWorker());
+ nSessionVariables = list_length(queryDesc->plannedstmt->sessionVariables);
+
+ /* create the array used for passing values of used session variables */
+ estate->es_session_variables = (SessionVariableValue *)
+ palloc(nSessionVariables * sizeof(SessionVariableValue));
+
+ /* fill the array */
+ foreach_oid(varid, queryDesc->plannedstmt->sessionVariables)
+ {
+ /*
+ * Permission check should be executed on all explicitly used
+ * variables in the query. For implicitly used variable
+ * (like base node of assignment indirect) we cannot do permission
+ * check, because we need read the value (and user can have
+ * only UPDATE variable). In this case the permission check
+ * is executed in write time.
+ */
+ if (varid != queryDesc->plannedstmt->exclSelectPermCheckVarid)
+ {
+ AclResult aclresult;
+
+ aclresult = object_aclcheck(VariableRelationId, varid,
+ GetUserId(), ACL_SELECT);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE,
+ get_session_variable_name(varid));
+ }
+
+ estate->es_session_variables[i].value =
+ GetSessionVariable(varid,
+ &estate->es_session_variables[i].isnull);
+
+ i++;
+ }
+
+ estate->es_num_session_variables = nSessionVariables;
+ }
+
/*
* Fill in the query environment, if any, from queryDesc.
*/
diff --git a/src/backend/executor/meson.build b/src/backend/executor/meson.build
index 2cea41f8771..491092fcc4c 100644
--- a/src/backend/executor/meson.build
+++ b/src/backend/executor/meson.build
@@ -64,6 +64,7 @@ backend_sources += files(
'nodeWindowAgg.c',
'nodeWorktablescan.c',
'spi.c',
+ 'svariableReceiver.c',
'tqueue.c',
'tstoreReceiver.c',
)
diff --git a/src/backend/executor/svariableReceiver.c b/src/backend/executor/svariableReceiver.c
new file mode 100644
index 00000000000..c6163fb36f6
--- /dev/null
+++ b/src/backend/executor/svariableReceiver.c
@@ -0,0 +1,172 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.c
+ * An implementation of DestReceiver that stores the result value in
+ * a session variable.
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/executor/svariableReceiver.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "miscadmin.h"
+
+#include "access/detoast.h"
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "storage/lock.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+/*
+ * This DestReceiver is used by the LET command for storing the result to a
+ * session variable. The result has to have only one tuple with only one
+ * non-deleted attribute. The row counter (field "rows") is incremented
+ * after receiving a row, and an error is raised when there are no rows or
+ * there are more than one received rows. A received tuple cannot to have
+ * deleted attributes. The value is detoasted before storing it in the
+ * session variable.
+ */
+typedef struct
+{
+ DestReceiver pub;
+ Oid varid;
+ bool need_detoast; /* do we need to detoast the attribute? */
+ int rows; /* row counter */
+} SVariableState;
+
+/*
+ * Prepare to receive tuples from executor.
+ */
+static void
+svariableStartupReceiver(DestReceiver *self, int operation, TupleDesc typeinfo)
+{
+ SVariableState *myState = (SVariableState *) self;
+ LOCKTAG locktag PG_USED_FOR_ASSERTS_ONLY;
+ Form_pg_attribute attr;
+ Oid typid PG_USED_FOR_ASSERTS_ONLY;
+ Oid collid PG_USED_FOR_ASSERTS_ONLY;
+ int32 typmod PG_USED_FOR_ASSERTS_ONLY;
+
+ Assert(myState->pub.mydest == DestVariable);
+ Assert(OidIsValid(myState->varid));
+ Assert(SearchSysCacheExists1(VARIABLEOID, myState->varid));
+ Assert(typeinfo->natts == 1);
+
+#ifdef USE_ASSERT_CHECKING
+
+ SET_LOCKTAG_OBJECT(locktag,
+ MyDatabaseId,
+ VariableRelationId,
+ myState->varid,
+ 0);
+
+ Assert(LockHeldByMe(&locktag, AccessShareLock, false));
+
+#endif
+
+ attr = TupleDescAttr(typeinfo, 0);
+
+ Assert(!attr->attisdropped);
+
+#ifdef USE_ASSERT_CHECKING
+
+ get_session_variable_type_typmod_collid(myState->varid,
+ &typid,
+ &typmod,
+ &collid);
+
+ Assert(attr->atttypid == typid);
+ Assert(attr->atttypmod < 0 || attr->atttypmod == typmod);
+
+#endif
+
+ myState->need_detoast = attr->attlen == -1;
+ myState->rows = 0;
+}
+
+/*
+ * Receive a tuple from the executor and store it in the session variable.
+ */
+static bool
+svariableReceiveSlot(TupleTableSlot *slot, DestReceiver *self)
+{
+ SVariableState *myState = (SVariableState *) self;
+ Datum value;
+ bool isnull;
+ bool freeval = false;
+
+ /* make sure the tuple is fully deconstructed */
+ slot_getallattrs(slot);
+
+ value = slot->tts_values[0];
+ isnull = slot->tts_isnull[0];
+
+ if (myState->need_detoast && !isnull && VARATT_IS_EXTERNAL(DatumGetPointer(value)))
+ {
+ value = PointerGetDatum(detoast_external_attr((struct varlena *)
+ DatumGetPointer(value)));
+ freeval = true;
+ }
+
+ myState->rows += 1;
+
+ if (myState->rows > 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_TOO_MANY_ROWS),
+ errmsg("expression returned more than one row")));
+
+ SetSessionVariable(myState->varid, value, isnull);
+
+ if (freeval)
+ pfree(DatumGetPointer(value));
+
+ return true;
+}
+
+/*
+ * Clean up at end of the executor run
+ */
+static void
+svariableShutdownReceiver(DestReceiver *self)
+{
+ if (((SVariableState *) self)->rows == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_NO_DATA_FOUND),
+ errmsg("expression returned no rows")));
+}
+
+/*
+ * Destroy the receiver when we are done with it
+ */
+static void
+svariableDestroyReceiver(DestReceiver *self)
+{
+ pfree(self);
+}
+
+/*
+ * Initially create a DestReceiver object.
+ */
+DestReceiver *
+CreateVariableDestReceiver(Oid varid)
+{
+ SVariableState *self = (SVariableState *) palloc0(sizeof(SVariableState));
+
+ self->pub.receiveSlot = svariableReceiveSlot;
+ self->pub.rStartup = svariableStartupReceiver;
+ self->pub.rShutdown = svariableShutdownReceiver;
+ self->pub.rDestroy = svariableDestroyReceiver;
+ self->pub.mydest = DestVariable;
+
+ self->varid = varid;
+
+ return (DestReceiver *) self;
+}
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f1..d8fc3d9fa69 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4375,6 +4375,16 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_LetStmt:
+ {
+ LetStmt *stmt = (LetStmt *) node;
+
+ if (WALK(stmt->target))
+ return true;
+ if (WALK(stmt->query))
+ return true;
+ }
+ break;
case T_PLAssignStmt:
{
PLAssignStmt *stmt = (PLAssignStmt *) node;
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 566ce5b3cb4..4a92888308a 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -338,6 +338,21 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
glob->lastPlanNodeId = 0;
glob->transientPlan = false;
glob->dependsOnRole = false;
+ glob->sessionVariables = NIL;
+
+ /*
+ * The (session) result variable should be stored to global, because
+ * it is not set in subquery. When this variable is used other than
+ * in base node of assignment indirection, we need to check the access
+ * rights (and then we need to detect this situation). The variable used
+ * like base node cannot be different than target (result) variable.
+ * Because we know the result variable before planner invocation, we
+ * can simply search of usage just this variable, and we don't need to
+ * to wait until the end of planning when we know basenodeSessionVarid.
+ */
+ glob->resultVariable = parse->resultVariable;
+ glob->basenodeSessionVarid = InvalidOid;
+ glob->basenodeSessionVarSelectCheck = false;
/*
* Assess whether it's feasible to use parallel mode for this query. We
@@ -576,6 +591,20 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
result->paramExecTypes = glob->paramExecTypes;
/* utilityStmt should be null, but we might as well copy it */
result->utilityStmt = parse->utilityStmt;
+
+ result->sessionVariables = glob->sessionVariables;
+
+ /*
+ * The session variable used (and only used) like base node
+ * for assignemnt indirection should be excluded from permission
+ * check.
+ */
+ if (OidIsValid(glob->basenodeSessionVarid) &&
+ (!glob->basenodeSessionVarSelectCheck))
+ result->exclSelectPermCheckVarid = glob->basenodeSessionVarid;
+ else
+ result->exclSelectPermCheckVarid = InvalidOid;
+
result->stmt_location = parse->stmt_location;
result->stmt_len = parse->stmt_len;
@@ -754,6 +783,13 @@ subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root,
*/
pull_up_subqueries(root);
+ /*
+ * Check if some subquery uses a session variable. The flag
+ * hasSessionVariables should be true if the query or some subquery uses a
+ * session variable.
+ */
+ pull_up_has_session_variables(root);
+
/*
* If this is a simple UNION ALL query, flatten it into an appendrel. We
* do this now because it requires applying pull_up_subqueries to the leaf
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 150e9f060ee..d071bd0c559 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -210,6 +210,9 @@ static List *set_returning_clause_references(PlannerInfo *root,
static List *set_windowagg_runcondition_references(PlannerInfo *root,
List *runcondition,
Plan *plan);
+static bool pull_up_has_session_variables_walker(Node *node,
+ PlannerInfo *root);
+static void record_plan_variable_dependency(PlannerInfo *root, Oid varid);
/*****************************************************************************
@@ -1318,6 +1321,50 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
return plan;
}
+/*
+ * Search usage of session variables in subqueries
+ */
+void
+pull_up_has_session_variables(PlannerInfo *root)
+{
+ Query *query = root->parse;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ }
+ else
+ {
+ (void) query_tree_walker(query,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+}
+
+static bool
+pull_up_has_session_variables_walker(Node *node, PlannerInfo *root)
+{
+ if (node == NULL)
+ return false;
+ if (IsA(node, Query))
+ {
+ Query *query = (Query *) node;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ return false;
+ }
+
+ /* recurse into subselects */
+ return query_tree_walker((Query *) node,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+ return expression_tree_walker(node, pull_up_has_session_variables_walker,
+ (void *) root);
+}
+
/*
* set_indexonlyscan_references
* Do set_plan_references processing on an IndexOnlyScan
@@ -2018,8 +2065,9 @@ copyVar(Var *var)
* This is code that is common to all variants of expression-fixing.
* We must look up operator opcode info for OpExpr and related nodes,
* add OIDs from regclass Const nodes into root->glob->relationOids, and
- * add PlanInvalItems for user-defined functions into root->glob->invalItems.
- * We also fill in column index lists for GROUPING() expressions.
+ * add PlanInvalItems for user-defined functions and session variables into
+ * root->glob->invalItems. We also fill in column index lists for GROUPING()
+ * expressions.
*
* We assume it's okay to update opcode info in-place. So this could possibly
* scribble on the planner's input data structures, but it's OK.
@@ -2109,6 +2157,13 @@ fix_expr_common(PlannerInfo *root, Node *node)
g->cols = cols;
}
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ record_plan_variable_dependency(root, p->paramvarid);
+ }
}
/*
@@ -2118,6 +2173,10 @@ fix_expr_common(PlannerInfo *root, Node *node)
* If it's a PARAM_MULTIEXPR, replace it with the appropriate Param from
* root->multiexpr_params; otherwise no change is needed.
* Just for paranoia's sake, we make a copy of the node in either case.
+ *
+ * If it's a PARAM_VARIABLE, then we collect used session variables in
+ * the list root->glob->sessionVariable. Also, assign the parameter's
+ * "paramid" to the parameter's position in that list.
*/
static Node *
fix_param_node(PlannerInfo *root, Param *p)
@@ -2136,6 +2195,62 @@ fix_param_node(PlannerInfo *root, Param *p)
elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid);
return copyObject(list_nth(params, colno - 1));
}
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ int n = 0;
+ bool found = false;
+
+ /* we will modify object */
+ p = (Param *) copyObject(p);
+
+ /*
+ * Now, we can actualize list of session variables, and we can
+ * complete paramid parameter.
+ */
+ foreach_oid(varid, root->glob->sessionVariables)
+ {
+ if (varid == p->paramvarid)
+ {
+ p->paramid = n;
+ found = true;
+ break;
+ }
+ n += 1;
+ }
+
+ if (!found)
+ {
+ root->glob->sessionVariables = lappend_oid(root->glob->sessionVariables,
+ p->paramvarid);
+ p->paramid = n;
+ }
+
+ /*
+ * We do SELECT permission check of all variables used by
+ * the query excluding the variable that is used only as base node
+ * of assignment indirection. The variable id assigned to this param
+ * should be same like resultVariable id, and this param should be
+ * used only once in query. When the variable is referenced by any
+ * other param, we should to do SELECT permission check for this variable
+ * too.
+ */
+ if (p->parambasenode)
+ {
+ Assert(!OidIsValid(root->glob->basenodeSessionVarid));
+ Assert(root->glob->resultVariable == p->paramvarid);
+
+ root->glob->basenodeSessionVarid = p->paramvarid;
+ }
+ else
+ {
+ if (p->paramvarid == root->glob->resultVariable)
+ root->glob->basenodeSessionVarSelectCheck = true;
+ }
+
+ return (Node *) p;
+ }
+
return (Node *) copyObject(p);
}
@@ -2197,7 +2312,10 @@ fix_alternative_subplan(PlannerInfo *root, AlternativeSubPlan *asplan,
* replacing Aggref nodes that should be replaced by initplan output Params,
* choosing the best implementation for AlternativeSubPlans,
* looking up operator opcode info for OpExpr and related nodes,
- * and adding OIDs from regclass Const nodes into root->glob->relationOids.
+ * adding OIDs from regclass Const nodes into root->glob->relationOids,
+ * assigning paramvarid to PARAM_VARIABLE params, and collecting the
+ * OIDs of session variables in the root->glob->sessionVariables list
+ * (paramvarid is the position of the session variable in this list).
*
* 'node': the expression to be modified
* 'rtoffset': how much to increment varnos by
@@ -2219,7 +2337,8 @@ fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec)
root->multiexpr_params != NIL ||
root->glob->lastPHId != 0 ||
root->minmax_aggs != NIL ||
- root->hasAlternativeSubPlans)
+ root->hasAlternativeSubPlans ||
+ root->hasSessionVariables)
{
return fix_scan_expr_mutator(node, &context);
}
@@ -3612,6 +3731,25 @@ record_plan_type_dependency(PlannerInfo *root, Oid typid)
}
}
+/*
+ * Record dependency on a session variable. The variable can be used as a
+ * session variable in an expression list, or as the target of a LET statement.
+ */
+static void
+record_plan_variable_dependency(PlannerInfo *root, Oid varid)
+{
+ PlanInvalItem *inval_item = makeNode(PlanInvalItem);
+
+ /* paramid is still session variable id */
+ inval_item->cacheId = VARIABLEOID;
+ inval_item->hashValue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ /* append this variable to global, register dependency */
+ root->glob->invalItems = lappend(root->glob->invalItems,
+ inval_item);
+}
+
/*
* extract_query_dependencies
* Given a rewritten, but not yet planned, query or queries
@@ -3697,9 +3835,9 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
}
/*
- * Ignore other utility statements, except those (such as EXPLAIN)
- * that contain a parsed-but-not-planned query. For those, we
- * just need to transfer our attention to the contained query.
+ * Ignore other utility statements, except those (such as EXPLAIN
+ * or LET) that contain a parsed-but-not-planned query. For those,
+ * we just need to transfer our attention to the contained query.
*/
query = UtilityContainsQuery(query->utilityStmt);
if (query == NULL)
@@ -3722,6 +3860,10 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
lappend_oid(context->glob->relationOids, rte->relid);
}
+ /* record dependency on the target variable of a LET command */
+ if (OidIsValid(query->resultVariable))
+ record_plan_variable_dependency(context, query->resultVariable);
+
/* And recurse into the query's subexpressions */
return query_tree_walker(query, extract_query_dependencies_walker,
context, 0);
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index d131a5bbc59..6fd04dadfcf 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -1573,6 +1573,9 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
/* If subquery had any RLS conditions, now main query does too */
parse->hasRowSecurity |= subquery->hasRowSecurity;
+ /* if the subquery had session variables, the main query does too */
+ parse->hasSessionVariables |= subquery->hasSessionVariables;
+
/*
* subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
* hasTargetSRFs, so no work needed on those flags
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 4622eaf709f..f9f00ada583 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -24,6 +24,7 @@
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "commands/session_variable.h"
#include "executor/executor.h"
#include "executor/functions.h"
#include "funcapi.h"
@@ -934,6 +935,13 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
if (param->paramkind == PARAM_EXTERN)
return false;
+ /* we don't support passing session variables to workers */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
+ return true;
+ }
+
if (param->paramkind != PARAM_EXEC ||
!list_member_int(context->safe_param_ids, param->paramid))
{
@@ -2389,6 +2397,7 @@ convert_saop_to_hashed_saop_walker(Node *node, void *context)
* value of the Param.
* 2. Fold stable, as well as immutable, functions to constants.
* 3. Reduce PlaceHolderVar nodes to their contained expressions.
+ * 4. Current value of session variable can be used for estimation too.
*--------------------
*/
Node *
@@ -2515,6 +2524,27 @@ eval_const_expressions_mutator(Node *node,
}
}
}
+ else if (param->paramkind == PARAM_VARIABLE &&
+ context->estimate)
+ {
+ int16 typLen;
+ bool typByVal;
+ Datum pval;
+ bool isnull;
+
+ get_typlenbyval(param->paramtype,
+ &typLen, &typByVal);
+
+ pval = GetSessionVariable(param->paramvarid, &isnull);
+
+ return (Node *) makeConst(param->paramtype,
+ param->paramtypmod,
+ param->paramcollid,
+ (int) typLen,
+ pval,
+ isnull,
+ typByVal);
+ }
/*
* Not replaceable, so just copy the Param (no need to
@@ -4720,7 +4750,8 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
querytree->limitOffset ||
querytree->limitCount ||
querytree->setOperations ||
- list_length(querytree->targetList) != 1)
+ (list_length(querytree->targetList) != 1) ||
+ querytree->hasSessionVariables)
goto fail;
/* If the function result is composite, resolve it */
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 76f58b3aca3..725f678e2fa 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -25,9 +25,12 @@
#include "postgres.h"
#include "access/sysattr.h"
+#include "catalog/namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
@@ -51,6 +54,7 @@
#include "utils/backend_status.h"
#include "utils/builtins.h"
#include "utils/guc.h"
+#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
@@ -83,6 +87,8 @@ static Query *transformCreateTableAsStmt(ParseState *pstate,
CreateTableAsStmt *stmt);
static Query *transformCallStmt(ParseState *pstate,
CallStmt *stmt);
+static Query *transformLetStmt(ParseState *pstate,
+ LetStmt *stmt);
static void transformLockingClause(ParseState *pstate, Query *qry,
LockingClause *lc, bool pushedDown);
#ifdef DEBUG_NODE_TESTS_ENABLED
@@ -414,6 +420,7 @@ transformStmt(ParseState *pstate, Node *parseTree)
case T_UpdateStmt:
case T_DeleteStmt:
case T_MergeStmt:
+ case T_LetStmt:
(void) test_raw_expression_coverage(parseTree, NULL);
break;
default:
@@ -493,6 +500,11 @@ transformStmt(ParseState *pstate, Node *parseTree)
(CallStmt *) parseTree);
break;
+ case T_LetStmt:
+ result = transformLetStmt(pstate,
+ (LetStmt *) parseTree);
+ break;
+
default:
/*
@@ -545,6 +557,7 @@ stmt_requires_parse_analysis(RawStmt *parseTree)
case T_SelectStmt:
case T_ReturnStmt:
case T_PLAssignStmt:
+ case T_LetStmt:
result = true;
break;
@@ -653,6 +666,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1078,6 +1092,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1543,6 +1558,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, stmt->lockingClause)
{
@@ -1769,12 +1785,241 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
return qry;
}
+/*
+ * transformLetStmt -
+ * transform an Let Statement
+ */
+static Query *
+transformLetStmt(ParseState *pstate, LetStmt *stmt)
+{
+ Query *query;
+ Query *result;
+ List *exprList = NIL;
+ List *exprListCoer = NIL;
+ ListCell *lc;
+ ListCell *indirection_head = NULL;
+ Query *selectQuery;
+ Oid varid;
+ char *attrname = NULL;
+ bool not_unique;
+ bool is_rowtype;
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+ List *names = NULL;
+ int indirection_start;
+ int i = 0;
+
+ /* there can't be any outer WITH to worry about */
+ Assert(pstate->p_ctenamespace == NIL);
+
+ names = NamesFromList(stmt->target);
+
+ /* locks the variable with an AccessShareLock */
+ varid = IdentifyVariable(names, &attrname, ¬_unique, false);
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("target \"%s\" of LET command is ambiguous",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ if (!OidIsValid(varid))
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ /*
+ * Calculate start of possible position of an indirection in list, and
+ * when it is inside the list, store pointer on first node of indirection.
+ */
+ indirection_start = list_length(names) - (attrname ? 1 : 0);
+ if (list_length(stmt->target) > indirection_start)
+ indirection_head = list_nth_cell(stmt->target, indirection_start);
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod, &collid);
+
+ is_rowtype = type_is_rowtype(typid);
+
+ if (attrname && !is_rowtype)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("cannot assign to field \"%s\" of session variable \"%s.%s\" because its type %s is not a composite type",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->location)));
+
+ pstate->p_expr_kind = EXPR_KIND_LET_TARGET;
+
+ /* we need to postpone conversion of "unknown" to text */
+ pstate->p_resolve_unknowns = false;
+
+ selectQuery = transformStmt(pstate, stmt->query);
+
+ /* the grammar should have produced a SELECT */
+ Assert(IsA(selectQuery, Query) && selectQuery->commandType == CMD_SELECT);
+
+ /*
+ * Generate an expression list for the LET that selects all the non-resjunk
+ * columns from the subquery.
+ */
+ exprList = NIL;
+ foreach_node(TargetEntry, tle, selectQuery->targetList)
+ {
+ if (tle->resjunk)
+ continue;
+
+ exprList = lappend(exprList, tle->expr);
+ }
+
+ /* don't allow multicolumn result */
+ if (list_length(exprList) != 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg_plural("assignment expression returned %d column",
+ "assignment expression returned %d columns",
+ list_length(exprList),
+ list_length(exprList)),
+ parser_errposition(pstate,
+ exprLocation((Node *) exprList))));
+
+ exprListCoer = NIL;
+
+ foreach(lc, exprList)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ Expr *coerced_expr;
+ Oid exprtypid;
+
+ /* now we can read the type of the expression */
+ exprtypid = exprType((Node *) expr);
+
+ if (indirection_head)
+ {
+ bool targetIsArray;
+ char *targetName;
+ Param *param;
+
+ targetName = get_session_variable_name(varid);
+ targetIsArray = OidIsValid(get_element_type(typid));
+
+ pstate->p_hasSessionVariables = true;
+
+ param = makeNode(Param);
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+
+ /*
+ * The parameter used as basenode has to have special
+ * mark, because requires special access when we do
+ * SELECT access check.
+ */
+ param->parambasenode = true;
+
+ coerced_expr = (Expr *)
+ transformAssignmentIndirection(pstate,
+ (Node *) param,
+ targetName,
+ targetIsArray,
+ typid,
+ typmod,
+ InvalidOid,
+ stmt->target,
+ indirection_head,
+ (Node *) expr,
+ COERCION_ASSIGNMENT,
+ stmt->location);
+ }
+ else
+ coerced_expr = (Expr *)
+ coerce_to_target_type(pstate,
+ (Node *) expr,
+ exprtypid,
+ typid, typmod,
+ COERCION_ASSIGNMENT,
+ COERCE_IMPLICIT_CAST,
+ stmt->location);
+
+ if (coerced_expr == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("variable \"%s.%s\" is of type %s, but expression is of type %s",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid),
+ format_type_be(exprtypid)),
+ errhint("You will need to rewrite or cast the expression."),
+ parser_errposition(pstate, exprLocation((Node *) expr))));
+
+ exprListCoer = lappend(exprListCoer, coerced_expr);
+ }
+
+ /* generate query's target list using the computed list of expressions */
+ query = makeNode(Query);
+ query->commandType = CMD_SELECT;
+
+ foreach(lc, exprListCoer)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ TargetEntry *tle;
+
+ tle = makeTargetEntry(expr,
+ i + 1,
+ FigureColname((Node *) expr),
+ false);
+ query->targetList = lappend(query->targetList, tle);
+ }
+
+ /* done building the range table and jointree */
+ query->rtable = pstate->p_rtable;
+ query->jointree = makeFromExpr(pstate->p_joinlist, NULL);
+
+ query->hasTargetSRFs = pstate->p_hasTargetSRFs;
+ query->hasSubLinks = pstate->p_hasSubLinks;
+ query->hasSessionVariables = pstate->p_hasSessionVariables;
+
+ /* this is top-level query */
+ query->canSetTag = true;
+
+ /*
+ * Save target session variable ID. It is used later for
+ * acquiring an AccessShareLock on target variable, setting
+ * plan dependency and finally for creating VariableDestReceiver.
+ */
+ query->resultVariable = varid;
+
+ assign_query_collations(pstate, query);
+
+ /*
+ * The query is executed as utility command by nested executor call.
+ * Assigned queryId is required in this case.
+ */
+ if (IsQueryIdEnabled())
+ JumbleQuery(query);
+
+ stmt->query = (Node *) query;
+
+ /* represent the command as a utility Query */
+ result = makeNode(Query);
+ result->commandType = CMD_UTILITY;
+ result->utilityStmt = (Node *) stmt;
+
+ return result;
+}
+
/*
* transformSetOperationStmt -
* transforms a set-operations tree
@@ -2020,6 +2265,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, lockingClause)
{
@@ -2495,6 +2741,7 @@ transformReturnStmt(ParseState *pstate, ReturnStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2562,6 +2809,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2852,9 +3100,15 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
/*
* Transform the target reference. Typically we will get back a Param
* node, but there's no reason to be too picky about its type.
+ *
+ * Session variables should not be used as target of a PL/pgSQL assign
+ * statement. So we should use a dedicated expression kind and disallow
+ * session variables there. The dedicated context allows to eliminate
+ * undesirable warnings about the possibility of a target PL/pgSQL variable
+ * shadowing a session variable.
*/
target = transformExpr(pstate, (Node *) cref,
- EXPR_KIND_UPDATE_TARGET);
+ EXPR_KIND_ASSIGN_TARGET);
targettype = exprType(target);
targettypmod = exprTypmod(target);
targetcollation = exprCollation(target);
@@ -2896,6 +3150,10 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
*/
type_id = exprType((Node *) tle->expr);
+ /*
+ * For indirection processing and additional casts we can use expr_kind
+ * EXPR_KIND_UPDATE_TARGET.
+ */
pstate->p_expr_kind = EXPR_KIND_UPDATE_TARGET;
if (indirection)
@@ -3038,6 +3296,8 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
(LockingClause *) lfirst(l), false);
}
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
+
assign_query_collations(pstate, qry);
/* this must be done after collations, for reliable comparison of exprs */
@@ -3311,6 +3571,16 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt)
true,
stmt->funccall->location);
+ /*
+ * The arguments of CALL statement are evaluated by a direct expression
+ * executor call. This path is unsupported yet, so block it. It will be
+ * enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
assign_expr_collations(pstate, node);
fexpr = castNode(FuncExpr, node);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index cf7eee458a3..8de7041e27b 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -297,7 +297,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
DropTransformStmt
DropUserMappingStmt ExplainStmt FetchStmt
GrantStmt GrantRoleStmt ImportForeignSchemaStmt IndexStmt InsertStmt
- ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
+ LetStmt ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
CreateFunctionStmt AlterFunctionStmt ReindexStmt RemoveAggrStmt
RemoveFuncStmt RemoveOperStmt RenameStmt ReturnStmt RevokeStmt RevokeRoleStmt
RuleActionStmt RuleActionStmtOrEmpty RuleStmt
@@ -742,7 +742,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
KEEP KEY KEYS
LABEL LANGUAGE LARGE_P LAST_P LATERAL_P
- LEADING LEAKPROOF LEAST LEFT LEVEL LIKE LIMIT LISTEN LOAD LOCAL
+ LEADING LEAKPROOF LEAST LEFT LET LEVEL LIKE LIMIT LISTEN LOAD LOCAL
LOCALTIME LOCALTIMESTAMP LOCATION LOCK_P LOCKED LOGGED
MAPPING MATCH MATCHED MATERIALIZED MAXVALUE MERGE MERGE_ACTION METHOD
@@ -1089,6 +1089,7 @@ stmt:
| ImportForeignSchemaStmt
| IndexStmt
| InsertStmt
+ | LetStmt
| ListenStmt
| RefreshMatViewStmt
| LoadStmt
@@ -12863,6 +12864,38 @@ opt_hold: /* EMPTY */ { $$ = 0; }
| WITHOUT HOLD { $$ = 0; }
;
+/*****************************************************************************
+ *
+ * QUERY:
+ * LET STATEMENT
+ *
+ *****************************************************************************/
+LetStmt: LET ColId opt_indirection '=' a_expr
+ {
+ LetStmt *n = makeNode(LetStmt);
+ SelectStmt *select;
+ ResTarget *res;
+
+ n->target = lcons(makeString($2),
+ check_indirection($3, yyscanner));
+
+ select = makeNode(SelectStmt);
+ res = makeNode(ResTarget);
+
+ /* create target list for implicit query */
+ res->name = NULL;
+ res->indirection = NIL;
+ res->val = (Node *) $5;
+ res->location = @5;
+
+ select->targetList = list_make1(res);
+ n->query = (Node *) select;
+
+ n->location = @2;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* QUERY:
@@ -17934,6 +17967,7 @@ unreserved_keyword:
| LARGE_P
| LAST_P
| LEAKPROOF
+ | LET
| LEVEL
| LISTEN
| LOAD
@@ -18547,6 +18581,7 @@ bare_label_keyword:
| LEAKPROOF
| LEAST
| LEFT
+ | LET
| LEVEL
| LIKE
| LISTEN
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 0ac8966e30f..de0a4a5653a 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -580,6 +580,11 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
+
/*
* There is intentionally no default: case here, so that the
* compiler will warn if we add a new ParseExprKind without
@@ -970,6 +975,10 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
case EXPR_KIND_CYCLE_MARK:
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 9caf1e481a2..55e4906ad76 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -17,6 +17,7 @@
#include "catalog/pg_aggregate.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
@@ -33,11 +34,13 @@
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "parser/parse_type.h"
+#include "storage/lmgr.h"
#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/timestamp.h"
+#include "utils/typcache.h"
#include "utils/xml.h"
/* GUC parameters */
@@ -106,6 +109,9 @@ static Expr *make_distinct_op(ParseState *pstate, List *opname,
Node *ltree, Node *rtree, int location);
static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
+static Node *makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location);
/*
@@ -499,6 +505,89 @@ transformIndirection(ParseState *pstate, A_Indirection *ind)
return result;
}
+/*
+ * Returns true if the given expression kind is valid for session variables.
+ * Session variables can be used everywhere where external parameters can be
+ * used. Session variables are not allowed in DDL commands or in constraints.
+ *
+ * An identifier can be parsed as a session variable only for expression kinds
+ * where session variables are allowed. This is the primary usage of this
+ * function.
+ *
+ * The second usage of this function is to decide whether a "column does not
+ * exist" or a "column or variable does not exist" error message should be
+ * printed. When we are in an expression where session variables cannot be
+ * used, we raise the first form of error message.
+ */
+static bool
+expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
+{
+ bool result = false;
+
+ switch (p_expr_kind)
+ {
+ case EXPR_KIND_NONE:
+ Assert(false); /* can't happen */
+ return false;
+
+ /* session variables allowed */
+ case EXPR_KIND_OTHER:
+ case EXPR_KIND_JOIN_ON:
+ case EXPR_KIND_FROM_SUBSELECT:
+ case EXPR_KIND_FROM_FUNCTION:
+ case EXPR_KIND_WHERE:
+ case EXPR_KIND_HAVING:
+ case EXPR_KIND_FILTER:
+ case EXPR_KIND_WINDOW_PARTITION:
+ case EXPR_KIND_WINDOW_ORDER:
+ case EXPR_KIND_WINDOW_FRAME_RANGE:
+ case EXPR_KIND_WINDOW_FRAME_ROWS:
+ case EXPR_KIND_WINDOW_FRAME_GROUPS:
+ case EXPR_KIND_SELECT_TARGET:
+ case EXPR_KIND_INSERT_TARGET:
+ case EXPR_KIND_UPDATE_SOURCE:
+ case EXPR_KIND_UPDATE_TARGET:
+ case EXPR_KIND_MERGE_WHEN:
+ case EXPR_KIND_MERGE_RETURNING:
+ case EXPR_KIND_GROUP_BY:
+ case EXPR_KIND_ORDER_BY:
+ case EXPR_KIND_DISTINCT_ON:
+ case EXPR_KIND_LIMIT:
+ case EXPR_KIND_OFFSET:
+ case EXPR_KIND_RETURNING:
+ case EXPR_KIND_VALUES:
+ case EXPR_KIND_VALUES_SINGLE:
+ case EXPR_KIND_ALTER_COL_TRANSFORM:
+ case EXPR_KIND_EXECUTE_PARAMETER:
+ case EXPR_KIND_POLICY:
+ case EXPR_KIND_CALL_ARGUMENT:
+ case EXPR_KIND_COPY_WHERE:
+ case EXPR_KIND_LET_TARGET:
+ result = true;
+ break;
+
+ /* session variables not allowed */
+ case EXPR_KIND_CHECK_CONSTRAINT:
+ case EXPR_KIND_DOMAIN_CHECK:
+ case EXPR_KIND_COLUMN_DEFAULT:
+ case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_INDEX_EXPRESSION:
+ case EXPR_KIND_INDEX_PREDICATE:
+ case EXPR_KIND_STATS_EXPRESSION:
+ case EXPR_KIND_TRIGGER_WHEN:
+ case EXPR_KIND_PARTITION_BOUND:
+ case EXPR_KIND_PARTITION_EXPRESSION:
+ case EXPR_KIND_GENERATED_COLUMN:
+ case EXPR_KIND_JOIN_USING:
+ case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ result = false;
+ break;
+ }
+
+ return result;
+}
+
/*
* Transform a ColumnRef.
*
@@ -575,6 +664,8 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
case EXPR_KIND_COPY_WHERE:
case EXPR_KIND_GENERATED_COLUMN:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
@@ -847,8 +938,61 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
}
/*
- * Throw error if no translation found.
+ * There are contexts where session variables are not allowed. We don't
+ * need to identify session variables in such a context, but identifying
+ * them allows us to raise meaningful error messages like "you cannot use
+ * session variables here".
*/
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind))
+ {
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* -----
+ * Session variables are shadowed by columns, routine variables or
+ * routine arguments. We certainly don't want to use a session variable
+ * when it is exactly shadowed, but a RTE like this is conceivable:
+ *
+ * CREATE TYPE t AS (c int);
+ * CREATE VARIABLE foo AS t;
+ * CREATE TABLE foo(a int, b int);
+ *
+ * SELECT foo.a, foo.b, foo.c FROM foo;
+ *
+ * However, that is very confusing, so we disallow it. We don't try to
+ * identify a variable if we know that it would be shadowed.
+ * -----
+ */
+ if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ {
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(cref->fields)),
+ parser_errposition(pstate, cref->location)));
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ node = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, cref->location);
+ }
+ }
+ }
+
+ /* throw an error if no translation was found */
if (node == NULL)
{
switch (crerr)
@@ -880,6 +1024,75 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
return node;
}
+/*
+ * Generate param variable for reference to session variable
+ */
+static Node *
+makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location)
+{
+ Param *param;
+
+ param = makeNode(Param);
+
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+ param->paramcollid = collid;
+
+ pstate->p_hasSessionVariables = true;
+
+ if (attrname != NULL)
+ {
+ TupleDesc tupdesc;
+ int i;
+
+ tupdesc = lookup_rowtype_tupdesc_noerror(typid, typmod, true);
+ if (!tupdesc)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("variable \"%s.%s\" is of type \"%s\", which is not a composite type",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, location)));
+
+ for (i = 0; i < tupdesc->natts; i++)
+ {
+ Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+ if (strcmp(attrname, NameStr(att->attname)) == 0 &&
+ !att->attisdropped)
+ {
+ /* success, so generate a FieldSelect expression */
+ FieldSelect *fselect = makeNode(FieldSelect);
+
+ fselect->arg = (Expr *) param;
+ fselect->fieldnum = i + 1;
+ fselect->resulttype = att->atttypid;
+ fselect->resulttypmod = att->atttypmod;
+ /* save attribute's collation for parse_collate.c */
+ fselect->resultcollid = att->attcollation;
+
+ ReleaseTupleDesc(tupdesc);
+ return (Node *) fselect;
+ }
+ }
+
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_COLUMN),
+ errmsg("could not identify column \"%s\" in variable \"%s.%s\"",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ parser_errposition(pstate, location)));
+ }
+
+ return (Node *) param;
+}
+
static Node *
transformParamRef(ParseState *pstate, ParamRef *pref)
{
@@ -1815,6 +2028,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_VALUES:
case EXPR_KIND_VALUES_SINGLE:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
case EXPR_KIND_CHECK_CONSTRAINT:
@@ -1858,6 +2072,9 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_GENERATED_COLUMN:
err = _("cannot use subquery in column generation expression");
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ err = _("cannot use subquery as target of assign statement");
+ break;
/*
* There is intentionally no default: case here, so that the
@@ -3215,6 +3432,10 @@ ParseExprKindName(ParseExprKind exprKind)
return "GENERATED AS";
case EXPR_KIND_CYCLE_MARK:
return "CYCLE";
+ case EXPR_KIND_ASSIGN_TARGET:
+ return "ASSIGN";
+ case EXPR_KIND_LET_TARGET:
+ return "LET";
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index 583bbbf232f..dc25f6dcd0e 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2656,6 +2656,8 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location)
err = _("set-returning functions are not allowed in column generation expressions");
break;
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
errkind = true;
break;
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
index 51d7703eff7..244efcddf32 100644
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -405,6 +405,7 @@ transformMergeStmt(ParseState *pstate, MergeStmt *stmt)
qry->hasTargetSRFs = false;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c
index b620766c938..b2f764b657f 100644
--- a/src/backend/tcop/dest.c
+++ b/src/backend/tcop/dest.c
@@ -38,6 +38,7 @@
#include "executor/functions.h"
#include "executor/tqueue.h"
#include "executor/tstoreReceiver.h"
+#include "executor/svariableReceiver.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
@@ -155,6 +156,9 @@ CreateDestReceiver(CommandDest dest)
case DestExplainSerialize:
return CreateExplainSerializeDestReceiver(NULL);
+
+ case DestVariable:
+ return CreateVariableDestReceiver(InvalidOid);
}
/* should never get here */
@@ -191,6 +195,7 @@ EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_o
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -237,6 +242,7 @@ NullCommand(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -281,6 +287,7 @@ ReadyForQuery(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 99a51877d34..7a508a3644f 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -49,6 +49,7 @@
#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
+#include "commands/session_variable.h"
#include "commands/subscriptioncmds.h"
#include "commands/tablecmds.h"
#include "commands/tablespace.h"
@@ -235,6 +236,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CallStmt:
case T_DoStmt:
+ case T_LetStmt:
{
/*
* Commands inside the DO block or the called procedure might
@@ -1067,6 +1069,11 @@ standard_ProcessUtility(PlannedStmt *pstmt,
break;
}
+ case T_LetStmt:
+ ExecuteLetStmt(pstate, (LetStmt *) parsetree, params,
+ queryEnv, qc);
+ break;
+
default:
/* All other statement types have event trigger support */
ProcessUtilitySlow(pstate, pstmt, queryString,
@@ -2206,6 +2213,10 @@ UtilityContainsQuery(Node *parsetree)
return UtilityContainsQuery(qry->utilityStmt);
return qry;
+ case T_LetStmt:
+ qry = castNode(Query, ((LetStmt *) parsetree)->query);
+ return qry;
+
default:
return NULL;
}
@@ -2404,6 +2415,10 @@ CreateCommandTag(Node *parsetree)
tag = CMDTAG_SELECT;
break;
+ case T_LetStmt:
+ tag = CMDTAG_LET;
+ break;
+
/* utility statements --- same whether raw or cooked */
case T_TransactionStmt:
{
@@ -3289,6 +3304,7 @@ GetCommandLogLevel(Node *parsetree)
break;
case T_PLAssignStmt:
+ case T_LetStmt:
lev = LOGSTMT_ALL;
break;
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 9e90acedb91..d6bdae9af7d 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -37,6 +37,7 @@
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablespace.h"
#include "common/keywords.h"
@@ -534,6 +535,7 @@ static char *generate_function_name(Oid funcid, int nargs,
static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2);
static void add_cast_to(StringInfo buf, Oid typid);
static char *generate_qualified_type_name(Oid typid);
+static char *generate_session_variable_name(Oid varid);
static text *string_to_text(char *str);
static char *flatten_reloptions(Oid relid);
static void get_reloptions(StringInfo buf, Datum reloptions);
@@ -8729,6 +8731,14 @@ get_parameter(Param *param, deparse_context *context)
return;
}
+ /* translate paramvarid to session variable name */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ return;
+ }
+
/*
* Alternatively, maybe it's a subplan output, which we print as a
* reference to the subplan. (We could drill down into the subplan and
@@ -13556,6 +13566,42 @@ generate_collation_name(Oid collid)
return result;
}
+/*
+ * generate_session_variable_name
+ * Compute the name to display for a session variable specified by OID
+ *
+ * The result includes all necessary quoting and schema-prefixing.
+ */
+static char *
+generate_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+ char *nspname;
+ char *result;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = NameStr(varform->varname);
+
+ if (!VariableIsVisible(varid))
+ nspname = get_namespace_name_or_temp(varform->varnamespace);
+ else
+ nspname = NULL;
+
+ result = quote_qualified_identifier(nspname, varname);
+
+ ReleaseSysCache(tup);
+
+ return result;
+}
+
/*
* Given a C string, produce a TEXT datum.
*
diff --git a/src/backend/utils/cache/plancache.c b/src/backend/utils/cache/plancache.c
index 6c2979d5c82..88574766861 100644
--- a/src/backend/utils/cache/plancache.c
+++ b/src/backend/utils/cache/plancache.c
@@ -58,6 +58,7 @@
#include "access/transam.h"
#include "catalog/namespace.h"
+#include "catalog/pg_variable.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
@@ -163,6 +164,7 @@ InitPlanCache(void)
CacheRegisterSyscacheCallback(AMOPOPID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNSERVEROID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNDATAWRAPPEROID, PlanCacheSysCallback, (Datum) 0);
+ CacheRegisterSyscacheCallback(VARIABLEOID, PlanCacheObjectCallback, (Datum) 0);
}
/*
@@ -2050,17 +2052,32 @@ ScanQueryForLocks(Query *parsetree, bool acquire)
/*
* Recurse into sublink subqueries, too. But we already did the ones in
- * the rtable and cteList.
+ * the rtable and cteList. We need to force a recursive call for session
+ * variables too, to find and lock variables used in the query (see
+ * ScanQueryWalker).
*/
- if (parsetree->hasSubLinks)
+ if (parsetree->hasSubLinks ||
+ parsetree->hasSessionVariables)
{
query_tree_walker(parsetree, ScanQueryWalker, &acquire,
QTW_IGNORE_RC_SUBQUERIES);
}
+
+ /* process session variables */
+ if (OidIsValid(parsetree->resultVariable))
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ }
}
/*
- * Walker to find sublink subqueries for ScanQueryForLocks
+ * Walker to find sublink subqueries or referenced session variables
+ * for ScanQueryForLocks
*/
static bool
ScanQueryWalker(Node *node, bool *acquire)
@@ -2075,6 +2092,20 @@ ScanQueryWalker(Node *node, bool *acquire)
ScanQueryForLocks(castNode(Query, sub->subselect), *acquire);
/* Fall through to process lefthand args of SubLink */
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ }
+ }
/*
* Do NOT recurse into Query nodes, because ScanQueryForLocks already
@@ -2205,7 +2236,9 @@ PlanCacheRelCallback(Datum arg, Oid relid)
/*
* PlanCacheObjectCallback
- * Syscache inval callback function for PROCOID and TYPEOID caches
+ * Syscache inval callback function for TYPEOID, PROCOID, NAMESPACEOID,
+ * OPEROID, AMOPOPID, FOREIGNSERVEROID, FOREIGNDATAWRAPPEROID and
+ * VARIABLEOID caches.
*
* Invalidate all plans mentioning the object with the specified hash value,
* or all plans mentioning any member of this cache if hashvalue == 0.
diff --git a/src/backend/utils/fmgr/fmgr.c b/src/backend/utils/fmgr/fmgr.c
index 782291d9998..093622fbdc4 100644
--- a/src/backend/utils/fmgr/fmgr.c
+++ b/src/backend/utils/fmgr/fmgr.c
@@ -2026,9 +2026,13 @@ get_call_expr_arg_stable(Node *expr, int argnum)
*/
if (IsA(arg, Const))
return true;
- if (IsA(arg, Param) &&
- ((Param *) arg)->paramkind == PARAM_EXTERN)
- return true;
+ if (IsA(arg, Param))
+ {
+ Param *p = (Param *) arg;
+
+ if (p->paramkind == PARAM_EXTERN || p->paramkind == PARAM_VARIABLE)
+ return true;
+ }
return false;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 78c0544e516..b3d4ef54456 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1228,8 +1228,8 @@ static const char *const sql_commands[] = {
"ABORT", "ALTER", "ANALYZE", "BEGIN", "CALL", "CHECKPOINT", "CLOSE", "CLUSTER",
"COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE",
"DELETE FROM", "DISCARD", "DO", "DROP", "END", "EXECUTE", "EXPLAIN",
- "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LISTEN", "LOAD", "LOCK",
- "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
+ "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LET",
+ "LISTEN", "LOAD", "LOCK", "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
"REASSIGN", "REFRESH MATERIALIZED VIEW", "REINDEX", "RELEASE",
"RESET", "REVOKE", "ROLLBACK",
"SAVEPOINT", "SECURITY LABEL", "SELECT", "SET", "SHOW", "START",
@@ -4693,6 +4693,14 @@ match_previous_words(int pattern_id,
else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES"))
COMPLETE_WITH("(");
+/* LET */
+ /* If prev. word is LET suggest a list of variables */
+ else if (Matches("LET"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ /* Complete LET <variable> with "=" */
+ else if (TailMatches("LET", MatchAny))
+ COMPLETE_WITH("=");
+
/* LOCK */
/* Complete LOCK [TABLE] [ONLY] with a list of tables */
else if (Matches("LOCK"))
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index bdac0c13bec..5060b8c9490 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -174,6 +174,7 @@ extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
extern List *NamesFromList(List *names);
extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+extern Oid IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror);
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 3d3c6eb24b5..5b45be5afaf 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -18,6 +18,7 @@
#ifndef PG_VARIABLE_H
#define PG_VARIABLE_H
+#include "access/xlogdefs.h"
#include "catalog/genbki.h"
#include "catalog/objectaddress.h"
#include "catalog/pg_variable_d.h"
@@ -35,6 +36,14 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* OID of entry in pg_type for variable's type */
Oid vartype BKI_LOOKUP(pg_type);
+ /*
+ * Used for identity check [oid, create_lsn].
+ *
+ * This column of the 8-byte XlogRecPtr type should be at an address that
+ * is divisible by 8, but before any column of type NameData.
+ */
+ XLogRecPtr varcreate_lsn;
+
/* variable name */
NameData varname;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
new file mode 100644
index 00000000000..2391b9ad443
--- /dev/null
+++ b/src/include/commands/session_variable.h
@@ -0,0 +1,30 @@
+/*-------------------------------------------------------------------------
+ *
+ * sessionvariable.h
+ * prototypes for sessionvariable.c.
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/commands/session_variable.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SESSIONVARIABLE_H
+#define SESSIONVARIABLE_H
+
+#include "nodes/params.h"
+#include "nodes/parsenodes.h"
+#include "parser/parse_node.h"
+#include "tcop/cmdtag.h"
+#include "utils/queryenvironment.h"
+
+extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
+extern Datum GetSessionVariable(Oid varid, bool *isNull);
+
+extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
+ QueryEnvironment *queryEnv, QueryCompletion *qc);
+
+#endif
diff --git a/src/include/executor/svariableReceiver.h b/src/include/executor/svariableReceiver.h
new file mode 100644
index 00000000000..db44d8b94c6
--- /dev/null
+++ b/src/include/executor/svariableReceiver.h
@@ -0,0 +1,22 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.h
+ * prototypes for svariableReceiver.c
+ *
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/executor/svariableReceiver.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SVARIABLE_RECEIVER_H
+#define SVARIABLE_RECEIVER_H
+
+#include "tcop/dest.h"
+
+extern DestReceiver *CreateVariableDestReceiver(Oid varid);
+
+#endif /* SVARIABLE_RECEIVER_H */
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 5b6cadb5a6c..79c0732aad5 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -642,6 +642,16 @@ typedef struct AsyncRequest
* tuples) */
} AsyncRequest;
+/* ----------------
+ * SessionVariableValue
+ * ----------------
+ */
+typedef struct SessionVariableValue
+{
+ bool isnull;
+ Datum value;
+} SessionVariableValue;
+
/* ----------------
* EState information
*
@@ -702,6 +712,10 @@ typedef struct EState
ParamListInfo es_param_list_info; /* values of external params */
ParamExecData *es_param_exec_vals; /* values of internal params */
+ /* Session variables info: */
+ int es_num_session_variables; /* number of used variables */
+ SessionVariableValue *es_session_variables; /* array of copies of values */
+
QueryEnvironment *es_queryEnv; /* query environment */
/* Other working state: */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 3decee1a98f..e935515e5b5 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -142,6 +142,9 @@ typedef struct Query
*/
int resultRelation pg_node_attr(query_jumble_ignore);
+ /* target variable of LET statement */
+ Oid resultVariable;
+
/* has aggregates in tlist or havingQual */
bool hasAggs pg_node_attr(query_jumble_ignore);
/* has window functions in tlist */
@@ -162,6 +165,8 @@ typedef struct Query
bool hasRowSecurity pg_node_attr(query_jumble_ignore);
/* parser has added an RTE_GROUP RTE */
bool hasGroupRTE pg_node_attr(query_jumble_ignore);
+ /* uses session variables */
+ bool hasSessionVariables pg_node_attr(query_jumble_ignore);
/* is a RETURN statement */
bool isReturn pg_node_attr(query_jumble_ignore);
@@ -2149,6 +2154,18 @@ typedef struct MergeStmt
ParseLoc stmt_len; /* length in bytes; 0 means "rest of string" */
} MergeStmt;
+/* ----------------------
+ * Let Statement
+ * ----------------------
+ */
+typedef struct LetStmt
+{
+ NodeTag type;
+ List *target; /* target variable */
+ Node *query; /* source expression */
+ ParseLoc location;
+} LetStmt;
+
/* ----------------------
* Select Statement
*
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index c24a1fc8514..852ab05d262 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -182,6 +182,18 @@ typedef struct PlannerGlobal
/* partition descriptors */
PartitionDirectory partition_directory pg_node_attr(read_write_ignore);
+
+ /* list of used session variables */
+ List *sessionVariables;
+
+ /* Oid of session variable used like target of LET command */
+ Oid resultVariable;
+
+ /* oid of session variable used like base node for assignment indirection */
+ Oid basenodeSessionVarid;
+
+ /* true, if we do SELECT permission check on basenodeSessionVarid */
+ bool basenodeSessionVarSelectCheck;
} PlannerGlobal;
/* macro for fetching the Plan associated with a SubPlan node */
@@ -532,6 +544,8 @@ struct PlannerInfo
bool placeholdersFrozen;
/* true if planning a recursive WITH item */
bool hasRecursion;
+ /* true if session variables were used */
+ bool hasSessionVariables;
/*
* The rangetable index for the RTE_GROUP RTE, or 0 if there is no
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index 658d76225e4..492b9d97e5c 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -138,6 +138,15 @@ typedef struct PlannedStmt
/* non-null if this is utility stmt */
Node *utilityStmt;
+ List *sessionVariables; /* OIDs for PARAM_VARIABLE Params */
+
+ /*
+ * The oid of session variable execluded from permission check.
+ * This session variable is used as base node of assignment indirection
+ * (and it is used only there).
+ */
+ int exclSelectPermCheckVarid;
+
/* statement location in source string (copied from Query) */
/* start location, or -1 if unknown */
ParseLoc stmt_location;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 7d3b4198f26..3cc2f019abb 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -378,6 +378,9 @@ typedef struct Const
* of the `paramid' field contain the SubLink's subLinkId, and
* the low-order 16 bits contain the column number. (This type
* of Param is also converted to PARAM_EXEC during planning.)
+ *
+ * PARAM_VARIABLE: The parameter is a reference to a session variable
+ * (paramvarid holds the variable's OID).
*/
typedef enum ParamKind
{
@@ -385,6 +388,7 @@ typedef enum ParamKind
PARAM_EXEC,
PARAM_SUBLINK,
PARAM_MULTIEXPR,
+ PARAM_VARIABLE,
} ParamKind;
typedef struct Param
@@ -397,6 +401,16 @@ typedef struct Param
int32 paramtypmod pg_node_attr(query_jumble_ignore);
/* OID of collation, or InvalidOid if none */
Oid paramcollid pg_node_attr(query_jumble_ignore);
+ /* OID of session variable if it is used */
+ Oid paramvarid pg_node_attr(query_jumble_ignore);
+
+ /*
+ * true if param is used as base node of assignment indirection
+ * (when target of LET statement is an array field or an record field).
+ * For this param we do not check SELECT access right, because this
+ * param is used just for execution of UPDATE operation.
+ */
+ bool parambasenode;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index 5a930199611..7a3b522b5ff 100644
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -131,4 +131,6 @@ extern void record_plan_function_dependency(PlannerInfo *root, Oid funcid);
extern void record_plan_type_dependency(PlannerInfo *root, Oid typid);
extern bool extract_query_dependencies_walker(Node *node, PlannerInfo *context);
+extern void pull_up_has_session_variables(PlannerInfo *root);
+
#endif /* PLANMAIN_H */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 793ace526df..431167f6b43 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -257,6 +257,7 @@ PG_KEYWORD("leading", LEADING, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("leakproof", LEAKPROOF, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("least", LEAST, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("left", LEFT, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("let", LET, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("level", LEVEL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("like", LIKE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("limit", LIMIT, RESERVED_KEYWORD, AS_LABEL)
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 994284019fb..0b7b69a4159 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -82,6 +82,8 @@ typedef enum ParseExprKind
EXPR_KIND_COPY_WHERE, /* WHERE condition in COPY FROM */
EXPR_KIND_GENERATED_COLUMN, /* generation expression for a column */
EXPR_KIND_CYCLE_MARK, /* cycle mark value */
+ EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */
+ EXPR_KIND_LET_TARGET, /* LET target */
} ParseExprKind;
@@ -244,6 +246,7 @@ struct ParseState
bool p_hasTargetSRFs;
bool p_hasSubLinks;
bool p_hasModifyingCTE;
+ bool p_hasSessionVariables;
Node *p_last_srf; /* most recent set-returning func/op found */
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index ea86954dded..22082c30008 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -186,6 +186,7 @@ PG_CMDTAG(CMDTAG_GRANT, "GRANT", true, false, false)
PG_CMDTAG(CMDTAG_GRANT_ROLE, "GRANT ROLE", false, false, false)
PG_CMDTAG(CMDTAG_IMPORT_FOREIGN_SCHEMA, "IMPORT FOREIGN SCHEMA", true, false, false)
PG_CMDTAG(CMDTAG_INSERT, "INSERT", false, false, true)
+PG_CMDTAG(CMDTAG_LET, "LET", false, false, false)
PG_CMDTAG(CMDTAG_LISTEN, "LISTEN", false, false, false)
PG_CMDTAG(CMDTAG_LOAD, "LOAD", false, false, false)
PG_CMDTAG(CMDTAG_LOCK_TABLE, "LOCK TABLE", false, false, false)
diff --git a/src/include/tcop/dest.h b/src/include/tcop/dest.h
index 00c092e3d7c..6ce3ea0e617 100644
--- a/src/include/tcop/dest.h
+++ b/src/include/tcop/dest.h
@@ -97,6 +97,7 @@ typedef enum
DestTransientRel, /* results sent to transient relation */
DestTupleQueue, /* results sent to tuple queue */
DestExplainSerialize, /* results are serialized and discarded */
+ DestVariable, /* results sent to session variable */
} CommandDest;
/* ----------------
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index bb99781c56e..1cff5efa6f7 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8264,7 +8264,8 @@ exec_is_simple_query(PLpgSQL_expr *expr)
query->sortClause ||
query->limitOffset ||
query->limitCount ||
- query->setOperations)
+ query->setOperations ||
+ query->hasSessionVariables)
return false;
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index c36660ce6d3..f22467186e3 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -431,3 +431,1235 @@ DROP VARIABLE public.var1;
DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+-- check access rights
+CREATE ROLE regress_noowner;
+CREATE VARIABLE var1 AS int;
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+-- should fail
+SET ROLE TO regress_noowner;
+SELECT var1;
+ERROR: permission denied for session variable var1
+SELECT sqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: SQL function "sqlfx" statement 1
+SELECT plpgsqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "$1 + var1"
+PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
+-- should be ok
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+-- should be ok
+SET ROLE TO regress_noowner;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+DROP ROLE regress_noowner;
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- start a new session
+\c
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- should fail, dependency
+DROP VARIABLE var1;
+ERROR: cannot drop session variable var1 because other objects depend on it
+DETAIL: view test_view depends on session variable var1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+NOTICE: drop cascades to view test_view
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+LET var1 = 'str1';
+LET var2 = 'str2';
+SELECT sqlfx1(sqlfx2('Hello'));
+ sqlfx1
+-------------------
+ str1, str2, Hello
+(1 row)
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+ QUERY PLAN
+------------------------------------------------------
+ Result
+ Output: sqlfx1(sqlfx2('Hello'::character varying))
+(2 rows)
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+SET plan_cache_mode TO force_generic_plan;
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 3.14
+(1 row)
+
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 6.28
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 9.42
+(1 row)
+
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 12.56
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+ERROR: function plpgsqlfx2() does not exist
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+SET plan_cache_mode TO DEFAULT;
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 1
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 55
+DROP VARIABLE var1;
+DROP TABLE testvar;
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+NOTICE: result array: {1,2,3,4,5,6,7,8,9,10}
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+-- should not crash (but is not supported yet)
+CALL p(v);
+ERROR: session variable cannot be used as an argument
+DO $$ BEGIN CALL p(v); END $$;
+ERROR: session variable cannot be used as an argument
+CONTEXT: SQL statement "CALL p(v)"
+PL/pgSQL function inline_code_block line 1 at CALL
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+-- should fail
+EXECUTE ptest(v);
+ERROR: session variable cannot be used as an argument
+DEALLOCATE ptest;
+DROP VARIABLE v;
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+-- should fail
+LET var1 = pi();
+ERROR: session variable "var1" doesn't exist
+LINE 1: LET var1 = pi();
+ ^
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+ var1
+------------------
+ 3.14159265358979
+(1 row)
+
+SET search_path TO svartest;
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+ var1
+------------------
+ 13.1415926535898
+(1 row)
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to session variable svartest.var1
+CREATE VARIABLE var1 AS text;
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+SELECT var1;
+ var1
+-------
+ hello
+(1 row)
+
+DROP VARIABLE var1;
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+-- should fail
+SELECT var1;
+ERROR: domain int_domain does not allow null values
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+ var1
+------
+ 1000
+(1 row)
+
+-- should fail
+LET var1 = 10;
+ERROR: value for domain int_domain violates check constraint "int_domain_check"
+-- should fail
+LET var1 = NULL;
+ERROR: domain int_domain does not allow null values
+-- note - domain defaults are not supported yet (like PLpgSQL)
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+ var1
+----------------------------------------
+ {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+(1 row)
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+DROP VARIABLE var1;
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+ var1
+------
+ 100
+(1 row)
+
+SET search_path to public, svartest;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table foo
+drop cascades to session variable var1
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+LET var2[var1] = 0;
+SELECT var2;
+ var2
+-----------
+ [2:2]={0}
+(1 row)
+
+DROP VARIABLE var1, var2;
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+SELECT var2;
+ var2
+------
+ {}
+(1 row)
+
+DROP VARIABLE var1, var2;
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+ERROR: syntax error at or near "LET"
+LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x;
+ ^
+-- should be ok
+LET var1 = generate_series(1, 1);
+-- should fail
+LET var1 = generate_series(1, 2);
+ERROR: expression returned more than one row
+LET var1 = generate_series(1, 0);
+ERROR: expression returned no rows
+DROP VARIABLE var1;
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+SELECT v1;
+ v1
+------------
+ (1,2,3.00)
+(1 row)
+
+SELECT v2;
+ v2
+---------------
+ (10,20,31.40)
+(1 row)
+
+SELECT (v1).*;
+ x | y | z
+---+---+------
+ 1 | 2 | 3.00
+(1 row)
+
+SELECT (v2).*;
+ x | y | z
+----+----+-------
+ 10 | 20 | 31.40
+(1 row)
+
+SELECT v1.x + v1.z;
+ ?column?
+----------
+ 4.00
+(1 row)
+
+SELECT v2.x + v2.z;
+ ?column?
+----------
+ 41.40
+(1 row)
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail
+SELECT v2.x;
+ERROR: permission denied for session variable v2
+SET ROLE TO DEFAULT;
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+ERROR: improper qualified name (too many dotted names): nodb.noschema.novar.nofield.nosubfield
+LET nodb.noschema.novar.nofield = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar.nofield
+LET nodb.noschema.novar = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar
+CREATE TYPE t1 AS (a int, b numeric, c text);
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+ v1
+----------------------------
+ (1,3.14159265358979,hello)
+(1 row)
+
+LET v1.b = 10.2222;
+SELECT v1;
+ v1
+-------------------
+ (1,10.2222,hello)
+(1 row)
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1
+LINE 1: LET v1.x = 10;
+ ^
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+ERROR: assignment expression returned 3 columns
+LINE 1: LET v1 = (NULL::t1).*;
+ ^
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+ v1
+-------------
+ (1,10.2222)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+ v1
+--------------
+ (1,10.2222,)
+(1 row)
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+ v1
+--------------
+ (10,10.3,20)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+ v1
+---------
+ (10,20)
+(1 row)
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+ERROR: cannot alter type "t1" because session variable "public.v1" uses it
+DROP VARIABLE v1;
+DROP TYPE t1;
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+ var1
+----------------------------------
+ (10,3.14159265358979,05-26-2023)
+(1 row)
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+ERROR: cannot alter table "svar_test" because session variable "public.var1" uses it
+-- should fail
+DROP TABLE svar_test;
+ERROR: cannot drop table svar_test because other objects depend on it
+DETAIL: session variable var1 depends on type svar_test
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+CREATE ROLE regress_var_test_role;
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+-- should fail
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+SELECT var1.a;
+ a
+------
+ 1000
+(1 row)
+
+SELECT var1;
+ var1
+------------
+ (1000,100)
+(1 row)
+
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+NOTICE: (0,100)
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+NOTICE: 0
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail again
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+-- should fail
+SELECT var1.a;
+ERROR: variable "public.var1" is of type "text", which is not a composite type
+LINE 1: SELECT var1.a;
+ ^
+SELECT var2.c;
+ERROR: could not identify column "c" in variable "public.var2"
+LINE 1: SELECT var2.c;
+ ^
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+-- should fail
+LET var1 = '1'::jsonb;
+ERROR: variable "public.var1" is of type integer, but expression is of type jsonb
+LINE 1: LET var1 = '1'::jsonb;
+ ^
+HINT: You will need to rewrite or cast the expression.
+-- should be ok
+LET var1 = '1'::jsonb::int;
+-- should fail
+LET var1.x = 10;
+ERROR: cannot assign to field "x" of session variable "public.var1" because its type integer is not a composite type
+LINE 1: LET var1.x = 10;
+ ^
+DROP VARIABLE var1;
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+-- should fail
+LET vartest.vartest = 1;
+ERROR: target "vartest.vartest" of LET command is ambiguous
+LINE 1: LET vartest.vartest = 1;
+ ^
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+ERROR: type "vartesttype" does not exist
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+ var1
+------------
+ {10.1,2.1}
+(1 row)
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+ERROR: set-returning functions are not allowed in LET
+LINE 1: LET var1[generate_series(1,3)] = 100;
+ ^
+DROP VARIABLE var1;
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+ var1
+--------------------
+ (10.2,"{0.0,0.0}")
+(1 row)
+
+LET var1.b[1] = 10.3;
+SELECT var1;
+ var1
+---------------------
+ (10.2,"{10.3,0.0}")
+(1 row)
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ count
+-------
+ 100
+(1 row)
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ QUERY PLAN
+-----------------------------------
+ Aggregate
+ -> Seq Scan on svar_test
+ Filter: ((a % 10) = zero)
+(3 rows)
+
+LET zero = (SELECT count(*) FROM svar_test);
+-- result should be 1000
+SELECT zero;
+ zero
+------
+ 1000
+(1 row)
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO on;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO off;
+DROP VIEW var1view;
+DROP VARIABLE var1;
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 100
+(1 row)
+
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 200
+(1 row)
+
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+---
+(0 rows)
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+ relname
+----------
+ pg_class
+(1 row)
+
+DROP VARIABLE var1;
+CREATE TABLE xxtab(avar int);
+INSERT INTO xxtab VALUES(333);
+CREATE TYPE xxtype AS (avar int);
+CREATE VARIABLE xxtab AS xxtype;
+INSERT INTO xxtab VALUES(10);
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+CREATE VARIABLE public.avar AS int;
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+ avar
+------
+
+
+(2 rows)
+
+DROP VARIABLE xxtab;
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+DROP VARIABLE public.avar;
+DROP TYPE xxtype;
+DROP TABLE xxtab;
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+CREATE TABLE public.svar(a int, b int);
+INSERT INTO public.svar VALUES(10, 20);
+LET public.svar = (100, 200, 300);
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT var1.* FROM vartest_foo;
+ ^
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+ a | b
+----+----
+ 10 | 20
+ 30 | 40
+(2 rows)
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT count(var1.*) FROM vartest_foo;
+ ^
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+ count
+-------
+ 2
+(1 row)
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table vartest.vartest_foo
+drop cascades to session variable vartest.var1
+CREATE TYPE ab AS (a integer, b integer);
+CREATE VARIABLE v_ab AS ab;
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+CREATE SCHEMA v_ab;
+CREATE VARIABLE v_ab.a AS integer;
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+SET search_path TO public;
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+-- should be ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+-- should be still ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+ERROR: session variable reference "xxx_am.b" is ambiguous
+LINE 1: SELECT xxx_am.b;
+ ^
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+ b
+----
+ 10
+(1 row)
+
+SELECT :"DBNAME".xxx_am.b;
+ b
+----
+ 20
+(1 row)
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+ b
+----
+ 10
+(1 row)
+
+SELECT x.b FROM xxx_am x;
+ b
+----
+ 10
+(1 row)
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+CREATE SCHEMA :"DBNAME";
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+SET search_path TO :"DBNAME";
+-- should be ambiguous
+SELECT :"DBNAME".b;
+ERROR: session variable reference "regression.b" is ambiguous
+LINE 1: SELECT "regression".b;
+ ^
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+ERROR: session variable reference "regression.regression.b" is ambiguous
+LINE 1: SELECT "regression"."regression".b;
+ ^
+CREATE TABLE :"DBNAME"(b int);
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+ b
+---
+(0 rows)
+
+DROP TABLE :"DBNAME";
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+RESET search_path;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index eeb0f94ca3c..e72360d5254 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -295,3 +295,886 @@ DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+
+-- check access rights
+CREATE ROLE regress_noowner;
+
+CREATE VARIABLE var1 AS int;
+
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+SELECT sqlfx(20);
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx(20);
+SELECT plpgsqlfx_sd(20);
+
+-- should fail
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+-- should be ok
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx_sd(20);
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+
+-- should be ok
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+
+DROP ROLE regress_noowner;
+
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- start a new session
+\c
+
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- should fail, dependency
+DROP VARIABLE var1;
+
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+
+LET var1 = 'str1';
+LET var2 = 'str2';
+
+SELECT sqlfx1(sqlfx2('Hello'));
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+
+SET plan_cache_mode TO force_generic_plan;
+
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+
+SET plan_cache_mode TO DEFAULT;
+
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP TABLE testvar;
+
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+
+-- should not crash (but is not supported yet)
+CALL p(v);
+
+DO $$ BEGIN CALL p(v); END $$;
+
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+
+-- should fail
+EXECUTE ptest(v);
+
+DEALLOCATE ptest;
+DROP VARIABLE v;
+
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+
+-- should fail
+LET var1 = pi();
+SELECT var1;
+
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+
+SET search_path TO svartest;
+
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS text;
+
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+
+-- should fail
+SELECT var1;
+
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+
+-- should fail
+LET var1 = 10;
+
+-- should fail
+LET var1 = NULL;
+
+-- note - domain defaults are not supported yet (like PLpgSQL)
+
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+
+SET search_path to public, svartest;
+
+SELECT var1;
+
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+LET var2[var1] = 0;
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+
+-- should be ok
+LET var1 = generate_series(1, 1);
+
+-- should fail
+LET var1 = generate_series(1, 2);
+LET var1 = generate_series(1, 0);
+
+DROP VARIABLE var1;
+
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+
+SELECT v1;
+SELECT v2;
+SELECT (v1).*;
+SELECT (v2).*;
+
+SELECT v1.x + v1.z;
+SELECT v2.x + v2.z;
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should fail
+SELECT v2.x;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+LET nodb.noschema.novar.nofield = 10;
+LET nodb.noschema.novar = 10;
+
+CREATE TYPE t1 AS (a int, b numeric, c text);
+
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+LET v1.b = 10.2222;
+SELECT v1;
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+
+DROP VARIABLE v1;
+DROP TYPE t1;
+
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+
+-- should fail
+DROP TABLE svar_test;
+
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+
+CREATE ROLE regress_var_test_role;
+
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+
+-- should fail
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should fail again
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+
+-- should fail
+SELECT var1.a;
+SELECT var2.c;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+
+CREATE VARIABLE var1 AS int;
+
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+
+-- should fail
+LET var1 = '1'::jsonb;
+
+-- should be ok
+LET var1 = '1'::jsonb::int;
+
+-- should fail
+LET var1.x = 10;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+
+-- should fail
+LET vartest.vartest = 1;
+
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+
+DROP VARIABLE var1;
+
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+LET var1.b[1] = 10.3;
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+LET zero = (SELECT count(*) FROM svar_test);
+
+-- result should be 1000
+SELECT zero;
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO on;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO off;
+
+DROP VIEW var1view;
+DROP VARIABLE var1;
+
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+
+DROP VARIABLE var1;
+
+CREATE TABLE xxtab(avar int);
+
+INSERT INTO xxtab VALUES(333);
+
+CREATE TYPE xxtype AS (avar int);
+
+CREATE VARIABLE xxtab AS xxtype;
+
+INSERT INTO xxtab VALUES(10);
+
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+
+-- should be ok
+SELECT avar FROM xxtab;
+
+CREATE VARIABLE public.avar AS int;
+
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+
+DROP VARIABLE xxtab;
+
+SELECT xxtab.avar FROM xxtab;
+
+DROP VARIABLE public.avar;
+
+DROP TYPE xxtype;
+
+DROP TABLE xxtab;
+
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+
+CREATE TABLE public.svar(a int, b int);
+
+INSERT INTO public.svar VALUES(10, 20);
+
+LET public.svar = (100, 200, 300);
+
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+
+CREATE TYPE ab AS (a integer, b integer);
+
+CREATE VARIABLE v_ab AS ab;
+
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+CREATE SCHEMA v_ab;
+
+CREATE VARIABLE v_ab.a AS integer;
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+
+SET search_path TO public;
+
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+
+-- should be ok
+SELECT xxx_am;
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+
+-- should be still ok
+SELECT xxx_am;
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+SELECT :"DBNAME".xxx_am.b;
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+SELECT x.b FROM xxx_am x;
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+
+CREATE SCHEMA :"DBNAME";
+
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+
+SET search_path TO :"DBNAME";
+
+-- should be ambiguous
+SELECT :"DBNAME".b;
+
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+
+CREATE TABLE :"DBNAME"(b int);
+
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+
+DROP TABLE :"DBNAME";
+
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+
+RESET search_path;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 53b414bd982..014d4219e8b 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1528,6 +1528,7 @@ LargeObjectDesc
Latch
LauncherLastStartTimesEntry
LerpFunc
+LetStmt
LexDescr
LexemeEntry
LexemeHashKey
@@ -2677,6 +2678,7 @@ SerializedTransactionState
Session
SessionBackupState
SessionEndType
+SessionVariableValue
SetConstraintState
SetConstraintStateData
SetConstraintTriggerData
@@ -2873,6 +2875,9 @@ SupportRequestRows
SupportRequestSelectivity
SupportRequestSimplify
SupportRequestWFuncMonotonic
+SVariable
+SVariableData
+SVariableState
Syn
SyncOps
SyncRepConfigData
--
2.49.0
[text/x-patch] v20250402-0001-Enhancing-catalog-for-support-session-variables-and-.patch (169.3K, ../../CAFj8pRAK_8ym1J=SAdin-vtL0PAachXgjWgU3QrhzinRdBX2sw@mail.gmail.com/10-v20250402-0001-Enhancing-catalog-for-support-session-variables-and-.patch)
download | inline diff:
From fd7c440bd8b44cb06b13a73789360e8640958fe1 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 15:41:55 +0100
Subject: [PATCH 01/21] Enhancing catalog for support session variables and
related support
This patch introduces new system catalog table pg_variable. This table holds metadata about
session variables created by command CREATE VARIABLE, and dropped by command DROP VARIABLE.
Both commands are implemented by this patch. Possibility to change owner, schema or rename.
Access to session variables can be controlled by SELECT or UPDATE rights. Both rights are
introduced by this patch too.
This patch enhancing pg_dump and psql to support session variables. The changes are related
to system catalog.
This patch is not short, but the code is simple.
---
doc/src/sgml/catalogs.sgml | 123 ++++-
doc/src/sgml/ddl.sgml | 40 +-
doc/src/sgml/func.sgml | 32 ++
doc/src/sgml/glossary.sgml | 15 +
doc/src/sgml/ref/allfiles.sgml | 3 +
.../sgml/ref/alter_default_privileges.sgml | 27 +-
doc/src/sgml/ref/alter_variable.sgml | 178 +++++++
doc/src/sgml/ref/comment.sgml | 1 +
doc/src/sgml/ref/create_schema.sgml | 12 +-
doc/src/sgml/ref/create_variable.sgml | 149 ++++++
doc/src/sgml/ref/drop_variable.sgml | 117 +++++
doc/src/sgml/ref/grant.sgml | 20 +-
doc/src/sgml/ref/psql-ref.sgml | 13 +
doc/src/sgml/ref/revoke.sgml | 8 +
doc/src/sgml/reference.sgml | 3 +
src/backend/catalog/Makefile | 1 +
src/backend/catalog/aclchk.c | 77 ++++
src/backend/catalog/dependency.c | 6 +
src/backend/catalog/meson.build | 1 +
src/backend/catalog/namespace.c | 221 +++++++++
src/backend/catalog/objectaddress.c | 121 ++++-
src/backend/catalog/pg_shdepend.c | 2 +
src/backend/catalog/pg_variable.c | 251 ++++++++++
src/backend/commands/alter.c | 9 +
src/backend/commands/dropcmds.c | 4 +
src/backend/commands/event_trigger.c | 4 +
src/backend/commands/seclabel.c | 1 +
src/backend/commands/tablecmds.c | 41 ++
src/backend/commands/typecmds.c | 15 +
src/backend/parser/gram.y | 105 ++++-
src/backend/parser/parse_utilcmd.c | 12 +
src/backend/tcop/utility.c | 20 +
src/backend/utils/adt/acl.c | 221 +++++++++
src/backend/utils/cache/lsyscache.c | 113 +++++
src/bin/pg_dump/common.c | 3 +
src/bin/pg_dump/dumputils.c | 6 +
src/bin/pg_dump/pg_backup.h | 2 +
src/bin/pg_dump/pg_backup_archiver.c | 9 +
src/bin/pg_dump/pg_dump.c | 190 ++++++++
src/bin/pg_dump/pg_dump.h | 15 +
src/bin/pg_dump/pg_dump_sort.c | 7 +
src/bin/pg_dump/t/002_pg_dump.pl | 64 +++
src/bin/psql/command.c | 3 +
src/bin/psql/describe.c | 100 +++-
src/bin/psql/describe.h | 3 +
src/bin/psql/help.c | 1 +
src/bin/psql/tab-complete.in.c | 43 +-
src/include/catalog/Makefile | 3 +-
src/include/catalog/meson.build | 1 +
src/include/catalog/namespace.h | 6 +
src/include/catalog/pg_default_acl.h | 1 +
src/include/catalog/pg_proc.dat | 23 +
src/include/catalog/pg_variable.h | 81 ++++
src/include/nodes/parsenodes.h | 16 +
src/include/parser/kwlist.h | 2 +
src/include/tcop/cmdtaglist.h | 3 +
src/include/utils/acl.h | 1 +
src/include/utils/lsyscache.h | 9 +
src/test/regress/expected/dependency.out | 17 +
src/test/regress/expected/oidjoins.out | 4 +
src/test/regress/expected/psql.out | 50 ++
.../regress/expected/session_variables.out | 433 ++++++++++++++++++
src/test/regress/parallel_schedule | 2 +-
src/test/regress/sql/dependency.sql | 14 +
src/test/regress/sql/psql.sql | 21 +
src/test/regress/sql/session_variables.sql | 297 ++++++++++++
src/tools/pgindent/typedefs.list | 4 +
67 files changed, 3364 insertions(+), 36 deletions(-)
create mode 100644 doc/src/sgml/ref/alter_variable.sgml
create mode 100644 doc/src/sgml/ref/create_variable.sgml
create mode 100644 doc/src/sgml/ref/drop_variable.sgml
create mode 100644 src/backend/catalog/pg_variable.c
create mode 100644 src/include/catalog/pg_variable.h
create mode 100644 src/test/regress/expected/session_variables.out
create mode 100644 src/test/regress/sql/session_variables.sql
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index fb050635551..8321b453e2c 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -369,6 +369,11 @@
<entry><link linkend="catalog-pg-user-mapping"><structname>pg_user_mapping</structname></link></entry>
<entry>mappings of users to foreign servers</entry>
</row>
+
+ <row>
+ <entry><link linkend="catalog-pg-variable"><structname>pg_variable</structname></link></entry>
+ <entry>session variables</entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -3361,7 +3366,8 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
<literal>S</literal> = sequence,
<literal>f</literal> = function,
<literal>T</literal> = type,
- <literal>n</literal> = schema
+ <literal>n</literal> = schema,
+ <literal>V</literal> = session variable
</para></entry>
</row>
@@ -9779,4 +9785,119 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</table>
</sect1>
+ <sect1 id="catalog-pg-variable">
+ <title><structname>pg_variable</structname></title>
+
+ <indexterm zone="catalog-pg-variable">
+ <primary>pg_variable</primary>
+ </indexterm>
+
+ <para>
+ The catalog <structname>pg_variable</structname> stores information about
+ session variables.
+ </para>
+
+ <table>
+ <title><structname>pg_variable</structname> Columns</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ Column Type
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>oid</structfield> <type>oid</type>
+ </para>
+ <para>
+ Row identifier
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartype</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-type"><structname>pg_type</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the variable's data type
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varname</structfield> <type>name</type>
+ </para>
+ <para>
+ Name of the session variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varnamespace</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the namespace that contains this variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varowner</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ Owner of the variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartypmod</structfield> <type>int4</type>
+ </para>
+ <para>
+ <structfield>vartypmod</structfield> records type-specific data
+ supplied at variable creation time (for example, the maximum
+ length of a <type>varchar</type> column). It is passed to
+ type-specific input functions and length coercion functions.
+ The value will generally be -1 for types that do not need <structfield>vartypmod</structfield>.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcollation</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-collation"><structname>pg_collation</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The defined collation of the variable, or zero if the variable is
+ not of a collatable data type.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varacl</structfield> <type>aclitem[]</type>
+ </para>
+ <para>
+ Access privileges; see
+ <xref linkend="sql-grant"/> and
+ <xref linkend="sql-revoke"/>
+ for details
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+ </sect1>
</chapter>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index d2082b7e88e..6a493c2f561 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -2018,6 +2018,7 @@ REVOKE ALL ON accounts FROM PUBLIC;
For sequences, this privilege also allows use of the
<function>currval</function> function.
For large objects, this privilege allows the object to be read.
+ For session variables, this privilege allows the object to be read.
</para>
</listitem>
</varlistentry>
@@ -2053,6 +2054,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<function>setval</function> functions.
For large objects, this privilege allows writing or truncating the
object.
+ For session variables, this privilege allows to set a value to the
+ object.
</para>
</listitem>
</varlistentry>
@@ -2296,7 +2299,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal> (and table-like objects),
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2311,7 +2315,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal>,
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2498,6 +2503,12 @@ REVOKE ALL ON accounts FROM PUBLIC;
<entry><literal>U</literal></entry>
<entry><literal>\dT+</literal></entry>
</row>
+ <row>
+ <entry><literal>SESSION VARIABLE</literal></entry>
+ <entry><literal>rw</literal></entry>
+ <entry><literal>none</literal></entry>
+ <entry><literal>\dV+</literal></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -5354,6 +5365,31 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
</para>
</sect1>
+ <sect1 id="ddl-session-variables">
+ <title>Session Variables</title>
+
+ <indexterm zone="ddl-session-variables">
+ <primary>Session variables</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ </indexterm>
+
+ <para>
+ Session variables are database objects that can hold a value.
+ Session variables, like relations, exist within a schema and their access
+ is controlled via <command>GRANT</command> and <command>REVOKE</command>
+ commands. A session variable can be created by the <command>CREATE
+ VARIABLE</command> command.
+ </para>
+
+ <para>
+ The session variable holds value in session memory. This value is private
+ to each session and is released when the session ends.
+ </para>
+ </sect1>
+
<sect1 id="ddl-others">
<title>Other Database Objects</title>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 2488e9ba998..010f7892fe0 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25589,6 +25589,25 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
</para></entry>
</row>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>has_session_variable_privilege</primary>
+ </indexterm>
+ <function>has_session_variable_privilege</function> (
+ <optional> <parameter>user</parameter> <type>name</type> or <type>oid</type>, </optional>
+ <parameter>session_variable</parameter> <type>text</type> or <type>oid</type>,
+ <parameter>privilege</parameter> <type>text</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Does user have privilege for session variable?
+ Allowable privilege types are
+ <literal>SELECT</literal>, and
+ <literal>UPDATE</literal>.
+ </para></entry>
+ </row>
+
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
@@ -26097,6 +26116,19 @@ SELECT relname FROM pg_class WHERE pg_table_is_visible(oid);
Is type (or domain) visible in search path?
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_variable_is_visible</primary>
+ </indexterm>
+ <function>pg_variable_is_visible</function> ( <parameter>variable</parameter> <type>oid</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Is session variable visible in search path?
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index b88cac598e9..83b13f98f28 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1708,6 +1708,21 @@
</glossdef>
</glossentry>
+ <glossentry id="glossary-session-variable">
+ <glossterm>Session variable</glossterm>
+ <glossdef>
+ <para>
+ A persistent database object that holds a value in session memory. This
+ value is private to each session and is released when the session ends.
+ Read or write access to session variables is controlled by privileges,
+ similar to other database objects.
+ </para>
+ <para>
+ For more information, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </glossdef>
+ </glossentry>
+
<glossentry id="glossary-shared-memory">
<glossterm>Shared memory</glossterm>
<glossdef>
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index f5be638867a..2f67de3e21b 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -47,6 +47,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY alterType SYSTEM "alter_type.sgml">
<!ENTITY alterUser SYSTEM "alter_user.sgml">
<!ENTITY alterUserMapping SYSTEM "alter_user_mapping.sgml">
+<!ENTITY alterVariable SYSTEM "alter_variable.sgml">
<!ENTITY alterView SYSTEM "alter_view.sgml">
<!ENTITY analyze SYSTEM "analyze.sgml">
<!ENTITY begin SYSTEM "begin.sgml">
@@ -99,6 +100,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY createType SYSTEM "create_type.sgml">
<!ENTITY createUser SYSTEM "create_user.sgml">
<!ENTITY createUserMapping SYSTEM "create_user_mapping.sgml">
+<!ENTITY createVariable SYSTEM "create_variable.sgml">
<!ENTITY createView SYSTEM "create_view.sgml">
<!ENTITY deallocate SYSTEM "deallocate.sgml">
<!ENTITY declare SYSTEM "declare.sgml">
@@ -147,6 +149,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY dropType SYSTEM "drop_type.sgml">
<!ENTITY dropUser SYSTEM "drop_user.sgml">
<!ENTITY dropUserMapping SYSTEM "drop_user_mapping.sgml">
+<!ENTITY dropVariable SYSTEM "drop_variable.sgml">
<!ENTITY dropView SYSTEM "drop_view.sgml">
<!ENTITY end SYSTEM "end.sgml">
<!ENTITY execute SYSTEM "execute.sgml">
diff --git a/doc/src/sgml/ref/alter_default_privileges.sgml b/doc/src/sgml/ref/alter_default_privileges.sgml
index 89aacec4fab..a5852d32566 100644
--- a/doc/src/sgml/ref/alter_default_privileges.sgml
+++ b/doc/src/sgml/ref/alter_default_privileges.sgml
@@ -51,6 +51,11 @@ GRANT { { USAGE | CREATE }
ON SCHEMAS
TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+GRANT { { SELECT | UPDATE }
+ [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+
REVOKE [ GRANT OPTION FOR ]
{ { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER | MAINTAIN }
[, ...] | ALL [ PRIVILEGES ] }
@@ -83,6 +88,12 @@ REVOKE [ GRANT OPTION FOR ]
ON SCHEMAS
FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
[ CASCADE | RESTRICT ]
+
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
+ [ CASCADE | RESTRICT ]
</synopsis>
</refsynopsisdiv>
@@ -117,14 +128,14 @@ REVOKE [ GRANT OPTION FOR ]
<para>
Currently,
only the privileges for schemas, tables (including views and foreign
- tables), sequences, functions, and types (including domains) can be
- altered. For this command, functions include aggregates and procedures.
- The words <literal>FUNCTIONS</literal> and <literal>ROUTINES</literal> are
- equivalent in this command. (<literal>ROUTINES</literal> is preferred
- going forward as the standard term for functions and procedures taken
- together. In earlier PostgreSQL releases, only the
- word <literal>FUNCTIONS</literal> was allowed. It is not possible to set
- default privileges for functions and procedures separately.)
+ tables), sequences, functions, types (including domains), and session
+ variables can be altered. For this command, functions include aggregates
+ and procedures. The words <literal>FUNCTIONS</literal> and
+ <literal>ROUTINES</literal> are equivalent in this command.
+ (<literal>ROUTINES</literal> is preferred going forward as the standard
+ term for functions and procedures taken together. In earlier PostgreSQL
+ releases, only the word <literal>FUNCTIONS</literal> was allowed. It is not
+ possible to set default privileges for functions and procedures separately.)
</para>
<para>
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
new file mode 100644
index 00000000000..96d2586423e
--- /dev/null
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -0,0 +1,178 @@
+<!--
+doc/src/sgml/ref/alter_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-altervariable">
+ <indexterm zone="sql-altervariable">
+ <primary>ALTER VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>altering</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>ALTER VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>ALTER VARIABLE</refname>
+ <refpurpose>
+ change the definition of a session variable
+ </refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable class="parameter">new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable class="parameter">new_name</replaceable>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> SET SCHEMA <replaceable class="parameter">new_schema</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>ALTER VARIABLE</command> command changes the definition of an
+ existing session variable. There are several subforms:
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>OWNER</literal></term>
+ <listitem>
+ <para>
+ This form changes the owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RENAME</literal></term>
+ <listitem>
+ <para>
+ This form changes the name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>SET SCHEMA</literal></term>
+ <listitem>
+ <para>
+ This form moves the session variable into another schema.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </para>
+
+ <para>
+ Only the owner or a superuser is allowed to alter a session variable.
+ In order to move a session variable from one schema to another, the user
+ must also have the <literal>CREATE</literal> privilege on the new schema (or
+ be a superuser).
+
+ In order to move the session variable ownership from one role to another,
+ the user must also be a direct or indirect member of the new
+ owning role, and that role must have the <literal>CREATE</literal> privilege
+ on the session variable's schema (or be a superuser). These restrictions
+ enforce that altering the owner doesn't do anything you couldn't do by
+ dropping and recreating the session variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <para>
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name (possibly schema-qualified) of the existing session variable
+ to alter.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_owner</replaceable></term>
+ <listitem>
+ <para>
+ The user name of the new owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_name</replaceable></term>
+ <listitem>
+ <para>
+ The new name for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_schema</replaceable></term>
+ <listitem>
+ <para>
+ The new schema for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To rename a session variable:
+<programlisting>
+ALTER VARIABLE foo RENAME TO boo;
+</programlisting>
+ </para>
+
+ <para>
+ To change the owner of the session variable <literal>boo</literal> to
+ <literal>joe</literal>:
+<programlisting>
+ALTER VARIABLE boo OWNER TO joe;
+</programlisting>
+ </para>
+
+ <para>
+ To change the schema of the session variable <literal>boo</literal> to
+ <literal>private</literal>:
+<programlisting>
+ALTER VARIABLE boo SET SCHEMA private;
+</programlisting>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ Session variables and this command in particular are a PostgreSQL extension.
+ </para>
+ </refsect1>
+
+ <refsect1 id="sql-altervariable-see-also">
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index 5b43c56b133..21cd80818fb 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -65,6 +65,7 @@ COMMENT ON
TRANSFORM FOR <replaceable>type_name</replaceable> LANGUAGE <replaceable>lang_name</replaceable> |
TRIGGER <replaceable class="parameter">trigger_name</replaceable> ON <replaceable class="parameter">table_name</replaceable> |
TYPE <replaceable class="parameter">object_name</replaceable> |
+ VARIABLE <replaceable class="parameter">object_name</replaceable> |
VIEW <replaceable class="parameter">object_name</replaceable>
} IS { <replaceable class="parameter">string_literal</replaceable> | NULL }
diff --git a/doc/src/sgml/ref/create_schema.sgml b/doc/src/sgml/ref/create_schema.sgml
index ed69298ccc6..d2bb265209b 100644
--- a/doc/src/sgml/ref/create_schema.sgml
+++ b/doc/src/sgml/ref/create_schema.sgml
@@ -103,9 +103,10 @@ CREATE SCHEMA IF NOT EXISTS AUTHORIZATION <replaceable class="parameter">role_sp
schema. Currently, only <command>CREATE
TABLE</command>, <command>CREATE VIEW</command>, <command>CREATE
INDEX</command>, <command>CREATE SEQUENCE</command>, <command>CREATE
- TRIGGER</command> and <command>GRANT</command> are accepted as clauses
- within <command>CREATE SCHEMA</command>. Other kinds of objects may
- be created in separate commands after the schema is created.
+ TRIGGER</command>, <command>GRANT</command> and <command>CREATE
+ VARIABLE</command> are accepted as clauses within <command>CREATE
+ SCHEMA</command>. Other kinds of objects may be created in separate
+ commands after the schema is created.
</para>
</listitem>
</varlistentry>
@@ -214,6 +215,11 @@ CREATE VIEW hollywood.winners AS
The <literal>IF NOT EXISTS</literal> option is a
<productname>PostgreSQL</productname> extension.
</para>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
</refsect1>
<refsect1>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
new file mode 100644
index 00000000000..6e988f2e472
--- /dev/null
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -0,0 +1,149 @@
+<!--
+doc/src/sgml/ref/create_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-createvariable">
+ <indexterm zone="sql-createvariable">
+ <primary>CREATE VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>defining</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>CREATE VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>CREATE VARIABLE</refname>
+ <refpurpose>define a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+</synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command creates a session variable.
+ Session variables, like relations, exist within a schema and their access is
+ controlled via the commands <command>GRANT</command> and <command>REVOKE</command>.
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a session variable's value returns NULL, unless its value is set to
+ something else in the current session with a <command>LET</command> command.
+ The content of a session variable is not transactional. This is the same as
+ regular variables in procedural languages.
+ </para>
+
+ <para>
+ Session variables are retrieved by the <command>SELECT</command>
+ command. Their value is set with the <command>LET</command> command.
+ </para>
+
+ <note>
+ <para>
+ Session variables can be <quote>shadowed</quote> by other identifiers.
+ For details, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </note>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+
+ <varlistentry id="sql-createvariable-if-not-exists">
+ <term><literal>IF NOT EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the name already exists. A notice is issued in
+ this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-name">
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-data_type">
+ <term><replaceable class="parameter">data_type</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the data type of the session
+ variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-collate">
+ <term><literal>COLLATE <replaceable>collation</replaceable></literal></term>
+ <listitem>
+ <para>
+ The <literal>COLLATE</literal> clause assigns a collation to the session
+ variable (which must be of a collatable data type). If not specified,
+ the data type's default collation is used.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para>
+ Use the <command>DROP VARIABLE</command> command to remove a session
+ variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ Create an date session variable <literal>var1</literal>:
+<programlisting>
+CREATE VARIABLE var1 AS date;
+</programlisting>
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
new file mode 100644
index 00000000000..5bdb3560f0b
--- /dev/null
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -0,0 +1,117 @@
+<!--
+doc/src/sgml/ref/drop_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-dropvariable">
+ <indexterm zone="sql-dropvariable">
+ <primary>DROP VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>removing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>DROP VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>DROP VARIABLE</refname>
+ <refpurpose>remove a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+DROP VARIABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ <command>DROP VARIABLE</command> removes a session variable.
+ A session variable can only be removed by its owner or a superuser.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>IF EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the session variable does not exist. A notice is
+ issued in this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of a session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>CASCADE</literal></term>
+ <listitem>
+ <para>
+ Automatically drop objects that depend on the session variable (such as
+ views), and in turn all objects that depend on those objects
+ (see <xref linkend="ddl-depend"/>).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RESTRICT</literal></term>
+ <listitem>
+ <para>
+ Refuse to drop the session variable if any objects depend on it. This is
+ the default.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To remove the session variable <literal>var1</literal>:
+
+<programlisting>
+DROP VARIABLE var1;
+</programlisting></para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>DROP VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index 999f657d5c0..c11860fa200 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -101,6 +101,12 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
[ WITH { ADMIN | INHERIT | SET } { OPTION | TRUE | FALSE } ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+GRANT { SELECT | UPDATE | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
@@ -119,8 +125,8 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
that grants privileges on a database object (table, column, view,
foreign table, sequence, database, foreign-data wrapper, foreign server,
function, procedure, procedural language, large object, configuration
- parameter, schema, tablespace, or type), and one that grants
- membership in a role. These variants are similar in many ways, but
+ parameter, schema, session variable, tablespace, or type), and one that
+ grants membership in a role. These variants are similar in many ways, but
they are different enough to be described separately.
</para>
@@ -236,9 +242,9 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
<para>
There is also an option to grant privileges on all objects of the same
type within one or more schemas. This functionality is currently supported
- only for tables, sequences, functions, and procedures. <literal>ALL
- TABLES</literal> also affects views and foreign tables, just like the
- specific-object <command>GRANT</command> command. <literal>ALL
+ only for tables, sequences, functions, procedures and variables.
+ <literal>ALL TABLES</literal> also affects views and foreign tables, just
+ like the specific-object <command>GRANT</command> command. <literal>ALL
FUNCTIONS</literal> also affects aggregate and window functions, but not
procedures, again just like the specific-object <command>GRANT</command>
command. Use <literal>ALL ROUTINES</literal> to include procedures.
@@ -518,8 +524,8 @@ GRANT admins TO joe;
</para>
<para>
- Privileges on databases, tablespaces, schemas, languages, and
- configuration parameters are
+ Privileges on databases, tablespaces, schemas, languages, session variables
+ and configuration parameters are
<productname>PostgreSQL</productname> extensions.
</para>
</refsect1>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index f7c8bc16a7f..4989cdc7ddb 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -2135,6 +2135,19 @@ SELECT $1 \parse stmt1
</listitem>
</varlistentry>
+ <varlistentry id="app-psql-meta-command-dv">
+ <term><literal>\dV[+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
+ <listitem>
+ <para>
+ Lists session variables.
+ If <replaceable class="parameter">pattern</replaceable> is
+ specified, only session variables whose names match the pattern are listed.
+ If the form <literal>\dV+</literal> is used, additional information
+ about each variable is shown, like access privileges and description.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="app-psql-meta-command-du">
<term><literal>\du[Sx+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
<listitem>
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index 8df492281a1..760fddb7c20 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -130,6 +130,14 @@ REVOKE [ { ADMIN | INHERIT | SET } OPTION FOR ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
[ CASCADE | RESTRICT ]
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ FROM { <replaceable class="parameter">role_specification</replaceable> | PUBLIC } [, ...]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+ [ CASCADE | RESTRICT ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index ff85ace83fc..25578f3946c 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -75,6 +75,7 @@
&alterType;
&alterUser;
&alterUserMapping;
+ &alterVariable;
&alterView;
&analyze;
&begin;
@@ -127,6 +128,7 @@
&createType;
&createUser;
&createUserMapping;
+ &createVariable;
&createView;
&deallocate;
&declare;
@@ -175,6 +177,7 @@
&dropType;
&dropUser;
&dropUserMapping;
+ &dropVariable;
&dropView;
&end;
&execute;
diff --git a/src/backend/catalog/Makefile b/src/backend/catalog/Makefile
index c090094ed08..2c20d60db19 100644
--- a/src/backend/catalog/Makefile
+++ b/src/backend/catalog/Makefile
@@ -45,6 +45,7 @@ OBJS = \
pg_shdepend.o \
pg_subscription.o \
pg_type.o \
+ pg_variable.o \
storage.o \
toasting.o
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 02a754cc30a..1e8ce752b90 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -64,6 +64,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -291,6 +292,9 @@ restrict_and_check_grant(bool is_grant, AclMode avail_goptions, bool all_privs,
case OBJECT_PARAMETER_ACL:
whole_mask = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ whole_mask = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", objtype);
/* not reached, but keep compiler quiet */
@@ -535,6 +539,10 @@ ExecuteGrantStmt(GrantStmt *stmt)
all_privileges = ACL_ALL_RIGHTS_PARAMETER_ACL;
errormsg = gettext_noop("invalid privilege type %s for parameter");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) stmt->objtype);
@@ -640,6 +648,9 @@ ExecGrantStmt_oids(InternalGrant *istmt)
case OBJECT_PARAMETER_ACL:
ExecGrant_Parameter(istmt);
break;
+ case OBJECT_VARIABLE:
+ ExecGrant_common(istmt, VariableRelationId, ACL_ALL_RIGHTS_VARIABLE, NULL);
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) istmt->objtype);
@@ -760,6 +771,18 @@ objectNamesToOids(ObjectType objtype, List *objnames, bool is_grant)
objects = lappend_oid(objects, parameterId);
}
break;
+
+ case OBJECT_VARIABLE:
+ foreach_node(RangeVar, varvar, objnames)
+ {
+ Oid relOid;
+
+ relOid = LookupVariable(varvar->schemaname,
+ varvar->relname,
+ false);
+ objects = lappend_oid(objects, relOid);
+ }
+ break;
}
return objects;
@@ -846,6 +869,32 @@ objectsInSchemaToOids(ObjectType objtype, List *nspnames)
table_close(rel, AccessShareLock);
}
break;
+ case OBJECT_VARIABLE:
+ {
+ ScanKeyData key;
+ Relation rel;
+ TableScanDesc scan;
+ HeapTuple tuple;
+
+ ScanKeyInit(&key,
+ Anum_pg_variable_varnamespace,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(namespaceId));
+
+ rel = table_open(VariableRelationId, AccessShareLock);
+ scan = table_beginscan_catalog(rel, 1, &key);
+
+ while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+ {
+ Oid oid = ((Form_pg_proc) GETSTRUCT(tuple))->oid;
+
+ objects = lappend_oid(objects, oid);
+ }
+
+ table_endscan(scan);
+ table_close(rel, AccessShareLock);
+ }
+ break;
default:
/* should not happen */
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
@@ -1005,6 +1054,10 @@ ExecAlterDefaultPrivilegesStmt(ParseState *pstate, AlterDefaultPrivilegesStmt *s
all_privileges = ACL_ALL_RIGHTS_SCHEMA;
errormsg = gettext_noop("invalid privilege type %s for schema");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) action->objtype);
@@ -1196,6 +1249,12 @@ SetDefaultACL(InternalDefaultACL *iacls)
this_privileges = ACL_ALL_RIGHTS_SCHEMA;
break;
+ case OBJECT_VARIABLE:
+ objtype = DEFACLOBJ_VARIABLE;
+ if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
+ this_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ break;
+
default:
elog(ERROR, "unrecognized object type: %d",
(int) iacls->objtype);
@@ -1439,6 +1498,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case DEFACLOBJ_NAMESPACE:
iacls.objtype = OBJECT_SCHEMA;
break;
+ case DEFACLOBJ_VARIABLE:
+ iacls.objtype = OBJECT_VARIABLE;
+ break;
default:
/* Shouldn't get here */
elog(ERROR, "unexpected default ACL type: %d",
@@ -1499,6 +1561,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case ParameterAclRelationId:
istmt.objtype = OBJECT_PARAMETER_ACL;
break;
+ case VariableRelationId:
+ istmt.objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unexpected object class %u", classid);
break;
@@ -2732,6 +2797,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("permission denied for type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("permission denied for session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("permission denied for view %s");
break;
@@ -2843,6 +2911,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("must be owner of type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("must be owner of session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("must be owner of view %s");
break;
@@ -2991,6 +3062,8 @@ pg_aclmask(ObjectType objtype, Oid object_oid, AttrNumber attnum, Oid roleid,
return ACL_NO_RIGHTS;
case OBJECT_TYPE:
return object_aclmask(TypeRelationId, object_oid, roleid, mask, how);
+ case OBJECT_VARIABLE:
+ return object_aclmask(VariableRelationId, object_oid, roleid, mask, how);
default:
elog(ERROR, "unrecognized object type: %d",
(int) objtype);
@@ -4250,6 +4323,10 @@ get_user_default_acl(ObjectType objtype, Oid ownerId, Oid nsp_oid)
defaclobjtype = DEFACLOBJ_NAMESPACE;
break;
+ case OBJECT_VARIABLE:
+ defaclobjtype = DEFACLOBJ_VARIABLE;
+ break;
+
default:
return NULL;
}
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 18316a3968b..9e0f648b74f 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -65,12 +65,14 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/comment.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "commands/extension.h"
#include "commands/policy.h"
#include "commands/publicationcmds.h"
+#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
#include "commands/trigger.h"
@@ -1444,6 +1446,10 @@ doDeletion(const ObjectAddress *object, int flags)
RemovePublicationById(object->objectId);
break;
+ case VariableRelationId:
+ DropVariableById(object->objectId);
+ break;
+
case CastRelationId:
case CollationRelationId:
case ConversionRelationId:
diff --git a/src/backend/catalog/meson.build b/src/backend/catalog/meson.build
index 1958ea9238a..ed44c877fca 100644
--- a/src/backend/catalog/meson.build
+++ b/src/backend/catalog/meson.build
@@ -32,6 +32,7 @@ backend_sources += files(
'pg_shdepend.c',
'pg_subscription.c',
'pg_type.c',
+ 'pg_variable.c',
'storage.c',
'toasting.c',
)
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index d97d632a7ef..4307cad15c7 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "common/hashfn_unstable.h"
#include "funcapi.h"
@@ -225,6 +226,7 @@ static bool TSParserIsVisibleExt(Oid prsId, bool *is_missing);
static bool TSDictionaryIsVisibleExt(Oid dictId, bool *is_missing);
static bool TSTemplateIsVisibleExt(Oid tmplId, bool *is_missing);
static bool TSConfigIsVisibleExt(Oid cfgid, bool *is_missing);
+static bool VariableIsVisibleExt(Oid varid, bool *is_missing);
static void recomputeNamespacePath(void);
static void AccessTempTableNamespace(bool force);
static void InitTempTableNamespace(void);
@@ -986,6 +988,84 @@ RelationIsVisibleExt(Oid relid, bool *is_missing)
return visible;
}
+/*
+ * VariableIsVisible
+ * Determine whether a variable (identified by OID) is visible in the
+ * current search path. Visible means "would be found by searching
+ * for the unqualified variable name".
+ */
+bool
+VariableIsVisible(Oid varid)
+{
+ return VariableIsVisibleExt(varid, NULL);
+}
+
+/*
+ * VariableIsVisibleExt
+ * As above, but if the variable isn't found and is_missing is not NULL,
+ * then set *is_missing = true and return false, instead of throwing
+ * an error. (Caller must initialize *is_missing = false.)
+ */
+static bool
+VariableIsVisibleExt(Oid varid, bool *is_missing)
+{
+ HeapTuple vartup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+ bool visible;
+
+ vartup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+ if (!HeapTupleIsValid(vartup))
+ {
+ if (is_missing != NULL)
+ {
+ *is_missing = true;
+ return false;
+ }
+
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+ }
+ varform = (Form_pg_variable) GETSTRUCT(vartup);
+
+ recomputeNamespacePath();
+
+ /*
+ * Quick check: if it ain't in the path at all, it ain't visible. We
+ * don't expect usage of session variables in the system namespace.
+ */
+ varnamespace = varform->varnamespace;
+ if (!list_member_oid(activeSearchPath, varnamespace))
+ visible = false;
+ else
+ {
+ /*
+ * If it is in the path, it might still not be visible; it could be
+ * hidden by another variable of the same name earlier in the path. So
+ * we must do a slow check for conflicting relations.
+ */
+ char *varname = NameStr(varform->varname);
+
+ visible = false;
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ if (namespaceId == varnamespace)
+ {
+ /* found it first in path */
+ visible = true;
+ break;
+ }
+ if (OidIsValid(get_varname_varid(varname, namespaceId)))
+ {
+ /* found something else first in path */
+ break;
+ }
+ }
+ }
+
+ ReleaseSysCache(vartup);
+
+ return visible;
+}
/*
* TypenameGetTypid
@@ -3289,6 +3369,133 @@ TSConfigIsVisibleExt(Oid cfgid, bool *is_missing)
return visible;
}
+/*
+ * Returns oid of session variable specified by possibly qualified identifier.
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariable(const char *nspname,
+ const char *varname,
+ bool missing_ok)
+{
+ Oid varoid = InvalidOid;
+
+ if (nspname)
+ {
+ Oid namespaceId = LookupExplicitNamespace(nspname, missing_ok);
+
+ /* if nspname is a known namespace, the variable must be there */
+ if (OidIsValid(namespaceId))
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+ }
+ }
+ else
+ {
+ /* iterate over the schemas on the search_path */
+ recomputeNamespacePath();
+
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+
+ if (OidIsValid(varoid))
+ break;
+ }
+ }
+
+ if (!OidIsValid(varoid) && !missing_ok)
+ {
+ if (nspname)
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s.%s\" does not exist",
+ nspname, varname)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" does not exist",
+ varname)));
+ }
+
+ return varoid;
+}
+
+/*
+ * Returns oid of session variable specified by possibly qualified identifier
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariableFromNameList(List *names,
+ bool missing_ok)
+{
+ char *catname = NULL;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ switch (list_length(names))
+ {
+ case 1:
+ varname = strVal(linitial(names));
+ break;
+ case 2:
+ nspname = strVal(linitial(names));
+ varname = strVal(lsecond(names));
+ break;
+ case 3:
+ catname = strVal(linitial(names));
+ nspname = strVal(lsecond(names));
+ varname = strVal(lthird(names));
+
+ /* check catalog name */
+ if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ break;
+ default:
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper session variable name (too many dotted names): %s",
+ NameListToString(names))));
+ break;
+ }
+
+ return LookupVariable(nspname, varname, missing_ok);
+}
+
+/*
+ * The input list contains names with indirection expressions used as the left
+ * part of LET statement. The following routine returns a new list with only
+ * initial strings (names) - without indirection expressions.
+ */
+List *
+NamesFromList(List *names)
+{
+ ListCell *l;
+ List *result = NIL;
+
+ foreach(l, names)
+ {
+ Node *n = lfirst(l);
+
+ if (IsA(n, String))
+ {
+ result = lappend(result, n);
+ }
+ else
+ break;
+ }
+
+ return result;
+}
/*
* DeconstructQualifiedName
@@ -5085,3 +5292,17 @@ pg_is_other_temp_schema(PG_FUNCTION_ARGS)
PG_RETURN_BOOL(isOtherTempNamespace(oid));
}
+
+Datum
+pg_variable_is_visible(PG_FUNCTION_ARGS)
+{
+ Oid oid = PG_GETARG_OID(0);
+ bool result;
+ bool is_missing = false;
+
+ result = VariableIsVisibleExt(oid, &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+ PG_RETURN_BOOL(result);
+}
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index d8eb8d3deaa..4a464dfea7e 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -62,6 +62,7 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -636,6 +637,20 @@ static const ObjectPropertyType ObjectProperty[] =
OBJECT_USER_MAPPING,
false
},
+ {
+ "session variable",
+ VariableRelationId,
+ VariableOidIndexId,
+ VARIABLEOID,
+ VARIABLENAMENSP,
+ Anum_pg_variable_oid,
+ Anum_pg_variable_varname,
+ Anum_pg_variable_varnamespace,
+ Anum_pg_variable_varowner,
+ Anum_pg_variable_varacl,
+ OBJECT_VARIABLE,
+ true
+ }
};
/*
@@ -831,6 +846,9 @@ static const struct object_type_map
},
{
"statistics object", OBJECT_STATISTIC_EXT
+ },
+ {
+ "session variable", OBJECT_VARIABLE
}
};
@@ -856,6 +874,7 @@ static ObjectAddress get_object_address_attrdef(ObjectType objtype,
bool missing_ok);
static ObjectAddress get_object_address_type(ObjectType objtype,
TypeName *typename, bool missing_ok);
+static ObjectAddress get_object_address_variable(List *object, bool missing_ok);
static ObjectAddress get_object_address_opcf(ObjectType objtype, List *object,
bool missing_ok);
static ObjectAddress get_object_address_opf_member(ObjectType objtype,
@@ -1127,6 +1146,9 @@ get_object_address(ObjectType objtype, Node *object,
missing_ok);
address.objectSubId = 0;
break;
+ case OBJECT_VARIABLE:
+ address = get_object_address_variable(castNode(List, object), missing_ok);
+ break;
/* no default, to let compiler warn about missing case */
}
@@ -2005,16 +2027,20 @@ get_object_address_defacl(List *object, bool missing_ok)
case DEFACLOBJ_NAMESPACE:
objtype_str = "schemas";
break;
+ case DEFACLOBJ_VARIABLE:
+ objtype_str = "variables";
+ break;
default:
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized default ACL object type \"%c\"", objtype),
- errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
+ errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
DEFACLOBJ_RELATION,
DEFACLOBJ_SEQUENCE,
DEFACLOBJ_FUNCTION,
DEFACLOBJ_TYPE,
- DEFACLOBJ_NAMESPACE)));
+ DEFACLOBJ_NAMESPACE,
+ DEFACLOBJ_VARIABLE)));
}
/*
@@ -2098,6 +2124,24 @@ textarray_to_strvaluelist(ArrayType *arr)
return list;
}
+/*
+ * Find the ObjectAddress for a session variable
+ */
+static ObjectAddress
+get_object_address_variable(List *object, bool missing_ok)
+{
+ ObjectAddress address;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ ObjectAddressSet(address, VariableRelationId, InvalidOid);
+
+ DeconstructQualifiedName(object, &nspname, &varname);
+ address.objectId = LookupVariable(nspname, varname, missing_ok);
+
+ return address;
+}
+
/*
* SQL-callable version of get_object_address
*/
@@ -2292,6 +2336,7 @@ pg_get_object_address(PG_FUNCTION_ARGS)
case OBJECT_TABCONSTRAINT:
case OBJECT_OPCLASS:
case OBJECT_OPFAMILY:
+ case OBJECT_VARIABLE:
objnode = (Node *) name;
break;
case OBJECT_ACCESS_METHOD:
@@ -2463,6 +2508,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
case OBJECT_STATISTIC_EXT:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
if (!object_ownercheck(address.classId, address.objectId, roleid))
aclcheck_error(ACLCHECK_NOT_OWNER, objtype,
NameListToString(castNode(List, object)));
@@ -3492,6 +3538,32 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
break;
}
+ case VariableRelationId:
+ {
+ char *nspname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ if (VariableIsVisible(object->objectId))
+ nspname = NULL;
+ else
+ nspname = get_namespace_name(varform->varnamespace);
+
+ appendStringInfo(&buffer, _("session variable %s"),
+ quote_qualified_identifier(nspname,
+ NameStr(varform->varname)));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
case TSParserRelationId:
{
HeapTuple tup;
@@ -3844,6 +3916,16 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
_("default privileges on new schemas belonging to role %s"),
rolename);
break;
+ case DEFACLOBJ_VARIABLE:
+ if (nspname)
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s in schema %s"),
+ rolename, nspname);
+ else
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s"),
+ rolename);
+ break;
default:
/* shouldn't get here */
if (nspname)
@@ -4660,6 +4742,10 @@ getObjectTypeDescription(const ObjectAddress *object, bool missing_ok)
appendStringInfoString(&buffer, "transform");
break;
+ case VariableRelationId:
+ appendStringInfoString(&buffer, "session variable");
+ break;
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
@@ -5766,6 +5852,10 @@ getObjectIdentityParts(const ObjectAddress *object,
appendStringInfoString(&buffer,
" on schemas");
break;
+ case DEFACLOBJ_VARIABLE:
+ appendStringInfoString(&buffer,
+ " on session variables");
+ break;
}
if (objname)
@@ -6006,6 +6096,33 @@ getObjectIdentityParts(const ObjectAddress *object,
}
break;
+ case VariableRelationId:
+ {
+ char *schema;
+ char *varname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ schema = get_namespace_name_or_temp(varform->varnamespace);
+ varname = NameStr(varform->varname);
+
+ appendStringInfo(&buffer, "%s",
+ quote_qualified_identifier(schema, varname));
+
+ if (objname)
+ *objname = list_make2(schema, pstrdup(varname));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
diff --git a/src/backend/catalog/pg_shdepend.c b/src/backend/catalog/pg_shdepend.c
index 536191284e8..c6fd1fa074f 100644
--- a/src/backend/catalog/pg_shdepend.c
+++ b/src/backend/catalog/pg_shdepend.c
@@ -46,6 +46,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
@@ -1714,6 +1715,7 @@ shdepReassignOwned_Owner(Form_pg_shdepend sdepForm, Oid newrole)
case DatabaseRelationId:
case TSConfigRelationId:
case TSDictionaryRelationId:
+ case VariableRelationId:
AlterObjectOwner_internal(sdepForm->classid,
sdepForm->objid,
newrole);
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
new file mode 100644
index 00000000000..29d967a2d5b
--- /dev/null
+++ b/src/backend/catalog/pg_variable.c
@@ -0,0 +1,251 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.c
+ * session variables
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/catalog/pg_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "catalog/dependency.h"
+#include "catalog/indexing.h"
+#include "catalog/namespace.h"
+#include "catalog/objectaccess.h"
+#include "catalog/pg_collation.h"
+#include "catalog/pg_namespace.h"
+#include "catalog/pg_variable.h"
+#include "miscadmin.h"
+#include "parser/parse_type.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+static ObjectAddress create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists);
+
+
+/*
+ * Creates entry in pg_variable table
+ */
+static ObjectAddress
+create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists)
+{
+ Acl *varacl;
+ NameData varname;
+ bool nulls[Natts_pg_variable];
+ Datum values[Natts_pg_variable];
+ Relation rel;
+ HeapTuple tup;
+ TupleDesc tupdesc;
+ ObjectAddress myself,
+ referenced;
+ ObjectAddresses *addrs;
+ Oid varid;
+
+ Assert(varName);
+ Assert(OidIsValid(varNamespace));
+ Assert(OidIsValid(varType));
+ Assert(OidIsValid(varOwner));
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ /*
+ * Check for duplicates. Note that this does not really prevent
+ * duplicates, it's here just to provide nicer error message in common
+ * case. The real protection is the unique key on the catalog.
+ */
+ if (SearchSysCacheExists2(VARIABLENAMENSP,
+ PointerGetDatum(varName),
+ ObjectIdGetDatum(varNamespace)))
+ {
+ if (if_not_exists)
+ ereport(NOTICE,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists, skipping",
+ varName)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists",
+ varName)));
+
+ table_close(rel, RowExclusiveLock);
+
+ return InvalidObjectAddress;
+ }
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, false, sizeof(nulls));
+
+ namestrcpy(&varname, varName);
+
+ varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
+
+ values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
+ values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
+ values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
+ values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
+ values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
+ values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+
+ varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
+ varNamespace);
+ if (varacl != NULL)
+ values[Anum_pg_variable_varacl - 1] = PointerGetDatum(varacl);
+ else
+ nulls[Anum_pg_variable_varacl - 1] = true;
+
+ tupdesc = RelationGetDescr(rel);
+
+ tup = heap_form_tuple(tupdesc, values, nulls);
+ CatalogTupleInsert(rel, tup);
+ Assert(OidIsValid(varid));
+
+ addrs = new_object_addresses();
+
+ ObjectAddressSet(myself, VariableRelationId, varid);
+
+ /* dependency on namespace */
+ ObjectAddressSet(referenced, NamespaceRelationId, varNamespace);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on used type */
+ ObjectAddressSet(referenced, TypeRelationId, varType);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on collation */
+ if (OidIsValid(varCollation) &&
+ varCollation != DEFAULT_COLLATION_OID)
+ {
+ ObjectAddressSet(referenced, CollationRelationId, varCollation);
+ add_exact_object_address(&referenced, addrs);
+ }
+
+ record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
+ free_object_addresses(addrs);
+
+ /* dependency on owner */
+ recordDependencyOnOwner(VariableRelationId, varid, varOwner);
+
+ /* dependencies on roles mentioned in default ACL */
+ recordDependencyOnNewAcl(VariableRelationId, varid, 0, varOwner, varacl);
+
+ /* dependency on extension */
+ recordDependencyOnCurrentExtension(&myself, false);
+
+ heap_freetuple(tup);
+
+ /* post creation hook for new function */
+ InvokeObjectPostCreateHook(VariableRelationId, varid, 0);
+
+ table_close(rel, RowExclusiveLock);
+
+ return myself;
+}
+
+/*
+ * Creates a new variable
+ *
+ * Used by CREATE VARIABLE command
+ */
+ObjectAddress
+CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
+{
+ Oid namespaceid;
+ AclResult aclresult;
+ Oid typid;
+ int32 typmod;
+ Oid varowner = GetUserId();
+ Oid collation;
+ Oid typcollation;
+ ObjectAddress variable;
+
+ namespaceid =
+ RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL);
+
+ typenameTypeIdAndMod(pstate, stmt->typeName, &typid, &typmod);
+
+ /* disallow pseudotypes */
+ if (get_typtype(typid) == TYPTYPE_PSEUDO)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("session variable cannot be pseudo-type %s",
+ format_type_be(typid))));
+
+ aclresult = object_aclcheck(TypeRelationId, typid, GetUserId(), ACL_USAGE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error_type(aclresult, typid);
+
+ typcollation = get_typcollation(typid);
+
+ if (stmt->collClause)
+ collation = LookupCollation(pstate,
+ stmt->collClause->collname,
+ stmt->collClause->location);
+ else
+ collation = typcollation;
+
+ /* complain if COLLATE is applied to an uncollatable type */
+ if (OidIsValid(collation) && !OidIsValid(typcollation))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("collations are not supported by type %s",
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->collClause->location)));
+
+ variable = create_variable(stmt->variable->relname,
+ namespaceid,
+ typid,
+ typmod,
+ varowner,
+ collation,
+ stmt->if_not_exists);
+
+ elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
+ stmt->variable->relname, variable.objectId);
+
+ return variable;
+}
+
+/*
+ * Drop variable by OID
+ */
+void
+DropVariableById(Oid varid)
+{
+ Relation rel;
+ HeapTuple tup;
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ CatalogTupleDelete(rel, &tup->t_self);
+
+ ReleaseSysCache(tup);
+
+ table_close(rel, RowExclusiveLock);
+}
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index c801c869c1c..c72a4adb07b 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/collationcmds.h"
#include "commands/dbcommands.h"
@@ -140,6 +141,10 @@ report_namespace_conflict(Oid classId, const char *name, Oid nspOid)
Assert(OidIsValid(nspOid));
msgfmt = gettext_noop("text search configuration \"%s\" already exists in schema \"%s\"");
break;
+ case VariableRelationId:
+ Assert(OidIsValid(nspOid));
+ msgfmt = gettext_noop("session variable \"%s\" already exists in schema \"%s\"");
+ break;
default:
elog(ERROR, "unsupported object class: %u", classId);
break;
@@ -435,6 +440,7 @@ ExecRenameStmt(RenameStmt *stmt)
case OBJECT_TSTEMPLATE:
case OBJECT_PUBLICATION:
case OBJECT_SUBSCRIPTION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
Relation catalog;
@@ -575,6 +581,7 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt,
case OBJECT_TSDICTIONARY:
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
+ case OBJECT_VARIABLE:
{
Relation catalog;
Oid classId;
@@ -657,6 +664,7 @@ AlterObjectNamespace_oid(Oid classId, Oid objid, Oid nspOid,
case TSDictionaryRelationId:
case TSTemplateRelationId:
case TSConfigRelationId:
+ case VariableRelationId:
{
Relation catalog;
@@ -887,6 +895,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
case OBJECT_TABLESPACE:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
diff --git a/src/backend/commands/dropcmds.c b/src/backend/commands/dropcmds.c
index ceb9a229b63..ebb585dc4a1 100644
--- a/src/backend/commands/dropcmds.c
+++ b/src/backend/commands/dropcmds.c
@@ -476,6 +476,10 @@ does_not_exist_skipping(ObjectType objtype, Node *object)
msg = gettext_noop("publication \"%s\" does not exist, skipping");
name = strVal(object);
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("session variable \"%s\" does not exist, skipping");
+ name = NameListToString(castNode(List, object));
+ break;
case OBJECT_COLUMN:
case OBJECT_DATABASE:
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index edc2c988e29..1839c1f82c5 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -2149,6 +2149,8 @@ stringify_grant_objtype(ObjectType objtype)
return "TABLESPACE";
case OBJECT_TYPE:
return "TYPE";
+ case OBJECT_VARIABLE:
+ return "VARIABLE";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
@@ -2232,6 +2234,8 @@ stringify_adefprivs_objtype(ObjectType objtype)
return "TABLESPACES";
case OBJECT_TYPE:
return "TYPES";
+ case OBJECT_VARIABLE:
+ return "VARIABLES";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
diff --git a/src/backend/commands/seclabel.c b/src/backend/commands/seclabel.c
index cee5d7bbb9c..57b4e6719c2 100644
--- a/src/backend/commands/seclabel.c
+++ b/src/backend/commands/seclabel.c
@@ -92,6 +92,7 @@ SecLabelSupportsObjectType(ObjectType objtype)
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
case OBJECT_USER_MAPPING:
+ case OBJECT_VARIABLE:
return false;
/*
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 10624353b0a..8702e695340 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -52,6 +52,7 @@
#include "catalog/pg_tablespace.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "catalog/storage.h"
#include "catalog/storage_xlog.h"
#include "catalog/toasting.h"
@@ -6886,6 +6887,7 @@ ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
* (possibly nested several levels deep in composite types, arrays, etc!).
* Eventually, we'd like to propagate the check or rewrite operation
* into such tables, but for now, just error out if we find any.
+ * Also, check if "typeOid" is used as type of some session variable.
*
* Caller should provide either the associated relation of a rowtype,
* or a type name (not both) for use in the error message, if any.
@@ -6949,6 +6951,45 @@ find_composite_type_dependencies(Oid typeOid, Relation origRelation,
continue;
}
+ /* check if the type is used as type of some session variable */
+ if (pg_depend->classid == VariableRelationId)
+ {
+ Oid varid = pg_depend->objid;
+
+ if (origTypeName)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ origTypeName,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter foreign table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_RELATION ||
+ origRelation->rd_rel->relkind == RELKIND_MATVIEW ||
+ origRelation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+
+ continue;
+ }
+
/* Else, ignore dependees that aren't relations */
if (pg_depend->classid != RelationRelationId)
continue;
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 3cb3ca1cca1..473d98ff062 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -53,6 +53,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_range.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablecmds.h"
#include "commands/typecmds.h"
@@ -3369,6 +3370,20 @@ get_rels_with_domain(Oid domainOid, LOCKMODE lockmode)
}
continue;
}
+ else if (pg_depend->classid == VariableRelationId)
+ {
+ /*
+ * We cannot to validate constraint inside session variables
+ * from other sessions, so better to fail if there are any
+ * session variable, that use this domain.
+ */
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter domain \"%s\" because session variable \"%s.%s\" uses it",
+ domainTypeName,
+ get_namespace_name(get_session_variable_namespace(pg_depend->objid)),
+ get_session_variable_name(pg_depend->objid))));
+ }
/* Else, ignore dependees that aren't user columns of relations */
/* (we assume system columns are never of domain types) */
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 0fc502a3a40..cf7eee458a3 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -52,6 +52,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_am.h"
#include "catalog/pg_trigger.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/trigger.h"
#include "gramparse.h"
@@ -285,8 +286,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
ConstraintsSetStmt CopyStmt CreateAsStmt CreateCastStmt
CreateDomainStmt CreateExtensionStmt CreateGroupStmt CreateOpClassStmt
CreateOpFamilyStmt AlterOpFamilyStmt CreatePLangStmt
- CreateSchemaStmt CreateSeqStmt CreateStmt CreateStatsStmt CreateTableSpaceStmt
- CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
+ CreateSchemaStmt CreateSeqStmt CreateSessionVarStmt CreateStmt CreateStatsStmt
+ CreateTableSpaceStmt CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
CreateAssertionStmt CreateTransformStmt CreateTrigStmt CreateEventTrigStmt
CreateUserStmt CreateUserMappingStmt CreateRoleStmt CreatePolicyStmt
CreatedbStmt DeclareCursorStmt DefineStmt DeleteStmt DiscardStmt DoStmt
@@ -783,8 +784,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
UESCAPE UNBOUNDED UNCONDITIONAL UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN
UNLISTEN UNLOGGED UNTIL UPDATE USER USING
- VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
- VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
+ VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARIABLE
+ VARIABLES VARYING VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
@@ -1050,6 +1051,7 @@ stmt:
| CreatePolicyStmt
| CreatePLangStmt
| CreateSchemaStmt
+ | CreateSessionVarStmt
| CreateSeqStmt
| CreateStmt
| CreateSubscriptionStmt
@@ -1592,6 +1594,7 @@ schema_stmt:
| CreateTrigStmt
| GrantStmt
| ViewStmt
+ | CreateSessionVarStmt
;
@@ -5263,6 +5266,34 @@ create_extension_opt_item:
}
;
+/*****************************************************************************
+ *
+ * QUERY :
+ * CREATE VARIABLE varname [AS] type
+ *
+ *****************************************************************************/
+
+CreateSessionVarStmt:
+ CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $3;
+ n->typeName = $5;
+ n->collClause = (CollateClause *) $6;
+ n->if_not_exists = false;
+ $$ = (Node *) n;
+ }
+ | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $6;
+ n->typeName = $8;
+ n->collClause = (CollateClause *) $9;
+ n->if_not_exists = true;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
@@ -7054,6 +7085,7 @@ object_type_any_name:
| TEXT_P SEARCH DICTIONARY { $$ = OBJECT_TSDICTIONARY; }
| TEXT_P SEARCH TEMPLATE { $$ = OBJECT_TSTEMPLATE; }
| TEXT_P SEARCH CONFIGURATION { $$ = OBJECT_TSCONFIGURATION; }
+ | VARIABLE { $$ = OBJECT_VARIABLE; }
;
/*
@@ -7930,6 +7962,14 @@ privilege_target:
n->objs = $2;
$$ = n;
}
+ | VARIABLE qualified_name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_OBJECT;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $2;
+ $$ = n;
+ }
| ALL TABLES IN_P SCHEMA name_list
{
PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
@@ -7975,6 +8015,14 @@ privilege_target:
n->objs = $5;
$$ = n;
}
+ | ALL VARIABLES IN_P SCHEMA name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_ALL_IN_SCHEMA;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $5;
+ $$ = n;
+ }
;
@@ -8172,6 +8220,7 @@ defacl_privilege_target:
| SEQUENCES { $$ = OBJECT_SEQUENCE; }
| TYPES_P { $$ = OBJECT_TYPE; }
| SCHEMAS { $$ = OBJECT_SCHEMA; }
+ | VARIABLES { $$ = OBJECT_VARIABLE; }
;
@@ -9960,6 +10009,24 @@ RenameStmt: ALTER AGGREGATE aggregate_with_argtypes RENAME TO name
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newname = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newname = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
opt_column: COLUMN
@@ -10321,6 +10388,24 @@ AlterObjectSchemaStmt:
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newschema = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newschema = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
/*****************************************************************************
@@ -10602,6 +10687,14 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec
n->newowner = $6;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name OWNER TO RoleSpec
+ {
+ AlterOwnerStmt *n = makeNode(AlterOwnerStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newowner = $6;
+ $$ = (Node *)n;
+ }
;
@@ -18011,6 +18104,8 @@ unreserved_keyword:
| VALIDATE
| VALIDATOR
| VALUE_P
+ | VARIABLE
+ | VARIABLES
| VARYING
| VERSION_P
| VIEW
@@ -18666,6 +18761,8 @@ bare_label_keyword:
| VALUE_P
| VALUES
| VARCHAR
+ | VARIABLE
+ | VARIABLES
| VARIADIC
| VERBOSE
| VERSION_P
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index 9c1541e1fea..26ccacace0b 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -105,6 +105,7 @@ typedef struct
List *indexes; /* CREATE INDEX items */
List *triggers; /* CREATE TRIGGER items */
List *grants; /* GRANT items */
+ List *variables; /* CREATE VARIABLE items */
} CreateSchemaStmtContext;
@@ -4087,6 +4088,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.indexes = NIL;
cxt.triggers = NIL;
cxt.grants = NIL;
+ cxt.variables = NIL;
/*
* Run through each schema element in the schema element list. Separate
@@ -4155,6 +4157,15 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.grants = lappend(cxt.grants, element);
break;
+ case T_CreateSessionVarStmt:
+ {
+ CreateSessionVarStmt *elp = (CreateSessionVarStmt *) element;
+
+ setSchemaName(cxt.schemaname, &elp->variable->schemaname);
+ cxt.variables = lappend(cxt.variables, element);
+ }
+ break;
+
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(element));
@@ -4168,6 +4179,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
result = list_concat(result, cxt.indexes);
result = list_concat(result, cxt.triggers);
result = list_concat(result, cxt.grants);
+ result = list_concat(result, cxt.variables);
return result;
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 25fe3d58016..99a51877d34 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -23,6 +23,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_inherits.h"
+#include "catalog/pg_variable.h"
#include "catalog/toasting.h"
#include "commands/alter.h"
#include "commands/async.h"
@@ -182,6 +183,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CreateRangeStmt:
case T_CreateRoleStmt:
case T_CreateSchemaStmt:
+ case T_CreateSessionVarStmt:
case T_CreateSeqStmt:
case T_CreateStatsStmt:
case T_CreateStmt:
@@ -1389,6 +1391,10 @@ ProcessUtilitySlow(ParseState *pstate,
}
break;
+ case T_CreateSessionVarStmt:
+ address = CreateVariable(pstate, (CreateSessionVarStmt *) parsetree);
+ break;
+
/*
* ************* object creation / destruction **************
*/
@@ -2341,6 +2347,9 @@ AlterObjectTypeCommandTag(ObjectType objtype)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_ALTER_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_ALTER_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
break;
@@ -2649,6 +2658,9 @@ CreateCommandTag(Node *parsetree)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_DROP_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_DROP_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
@@ -3225,6 +3237,10 @@ CreateCommandTag(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ tag = CMDTAG_CREATE_VARIABLE;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
@@ -3759,6 +3775,10 @@ GetCommandLogLevel(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ lev = LOGSTMT_DDL;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index ba14713fef2..6ce3b937dae 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -31,6 +31,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/proclang.h"
#include "commands/tablespace.h"
@@ -129,6 +130,8 @@ static AclMode convert_type_priv_string(text *priv_type_text);
static AclMode convert_parameter_priv_string(text *priv_text);
static AclMode convert_largeobject_priv_string(text *priv_text);
static AclMode convert_role_priv_string(text *priv_type_text);
+static Oid convert_session_variable_name(text *varname);
+static AclMode convert_session_variable_priv_string(text *priv_type_text);
static AclResult pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode);
static void RoleMembershipCacheCallback(Datum arg, int cacheid, uint32 hashvalue);
@@ -851,6 +854,10 @@ acldefault(ObjectType objtype, Oid ownerId)
world_default = ACL_NO_RIGHTS;
owner_default = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ world_default = ACL_NO_RIGHTS;
+ owner_default = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", (int) objtype);
world_default = ACL_NO_RIGHTS; /* keep compiler quiet */
@@ -948,6 +955,9 @@ acldefault_sql(PG_FUNCTION_ARGS)
case 'T':
objtype = OBJECT_TYPE;
break;
+ case 'V':
+ objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type abbreviation: %c", objtypec);
}
@@ -5016,6 +5026,217 @@ pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode)
return ACLCHECK_NO_PRIV;
}
+/*
+ * has_session_variable_privilege variants
+ * These are all named "has_session_variable_privilege" at the SQL level.
+ * They take various combinations of variable name, variable OID,
+ * user name, user OID, or implicit user = current_user.
+ *
+ * The result is a boolean value: true if user has the indicated
+ * privilege, false if not, or NULL if session variable doesn't
+ * exists.
+ */
+
+/*
+ * has_session_variable_privilege_name_name
+ * Check user privileges on a session variable given
+ * name username, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_name(PG_FUNCTION_ARGS)
+{
+ Name rolename = PG_GETARG_NAME(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*rolename));
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name
+ * Check user privileges on a session variable given
+ * text session variable and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_name(PG_FUNCTION_ARGS)
+{
+ text *varname = PG_GETARG_TEXT_PP(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name_id
+ * Check user privileges on a session variable given
+ * name usename, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_id(PG_FUNCTION_ARGS)
+{
+ Name username = PG_GETARG_NAME(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*username));
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id
+ * Check user privileges on a session variable given
+ * session variable oid, and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_id(PG_FUNCTION_ARGS)
+{
+ Oid varid = PG_GETARG_OID(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_name
+ * Check user privileges on a session variable given
+ * roleid, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_name(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_id
+ * Check user privileges on a session variable given
+ * roleid, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_id(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * Given a session variable name expressed as a string, look it up and return
+ * Oid
+ */
+static Oid
+convert_session_variable_name(text *varname)
+{
+ return LookupVariableFromNameList(textToQualifiedNameList(varname), true);
+}
+
+/*
+ * convert_variable_priv_string
+ * Convert text string to AclMode value.
+ */
+static AclMode
+convert_session_variable_priv_string(text *priv_type_text)
+{
+ static const priv_map session_variable_priv_map[] = {
+ {"SELECT", ACL_SELECT},
+ {"SELECT WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_SELECT)},
+ {"UPDATE", ACL_UPDATE},
+ {"UPDATE WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_UPDATE)},
+ {NULL, 0}
+ };
+
+ return convert_any_priv_string(priv_type_text, session_variable_priv_map);
+}
/*
* initialization function (called by InitPostgres)
diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index 82031c1e8e5..e04bb56ff06 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -39,6 +39,7 @@
#include "catalog/pg_subscription.h"
#include "catalog/pg_transform.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "utils/array.h"
@@ -3797,3 +3798,115 @@ get_subscription_name(Oid subid, bool missing_ok)
return subname;
}
+
+/* ---------- PG_VARIABLE CACHE ---------- */
+
+/*
+ * get_varname_varid
+ * Given name and namespace of variable, look up the OID.
+ */
+Oid
+get_varname_varid(const char *varname, Oid varnamespace)
+{
+ return GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(varnamespace));
+}
+
+/*
+ * get_session_variable_name
+ * Returns a palloc'd copy of the name of a given session variable.
+ */
+char *
+get_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = pstrdup(NameStr(varform->varname));
+
+ ReleaseSysCache(tup);
+
+ return varname;
+}
+
+/*
+ * get_session_variable_namespace
+ * Returns the pg_namespace OID associated with a given session variable.
+ */
+Oid
+get_session_variable_namespace(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varnamespace = varform->varnamespace;
+
+ ReleaseSysCache(tup);
+
+ return varnamespace;
+}
+
+/*
+ * Returns the type of the given session variable.
+ */
+Oid
+get_session_variable_type(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid vartype;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ vartype = varform->vartype;
+
+ ReleaseSysCache(tup);
+
+ return vartype;
+}
+
+/*
+ * Returns the type, typmod and collid of the given session variable.
+ */
+void
+get_session_variable_type_typmod_collid(Oid varid, Oid *typid, int32 *typmod,
+ Oid *collid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ *typid = varform->vartype;
+ *typmod = varform->vartypmod;
+ *collid = varform->varcollation;
+
+ ReleaseSysCache(tup);
+}
diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c
index 56b6c368acf..ba6b19dc9af 100644
--- a/src/bin/pg_dump/common.c
+++ b/src/bin/pg_dump/common.c
@@ -246,6 +246,9 @@ getSchemaData(Archive *fout, int *numTablesPtr)
pg_log_info("reading subscription membership of tables");
getSubscriptionTables(fout);
+ pg_log_info("reading variables");
+ getVariables(fout);
+
free(inhinfo); /* not needed any longer */
*numTablesPtr = numTables;
diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index 5ae77f76367..5161ee780ea 100644
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -511,6 +511,12 @@ do { \
CONVERT_PRIV('r', "SELECT");
CONVERT_PRIV('w', "UPDATE");
}
+ else if (strcmp(type, "VARIABLE") == 0 ||
+ strcmp(type, "VARIABLES") == 0)
+ {
+ CONVERT_PRIV('r', "SELECT");
+ CONVERT_PRIV('w', "UPDATE");
+ }
else
abort();
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index 658986de6f8..4070543d33b 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -134,12 +134,14 @@ typedef struct _restoreOptions
int selFunction;
int selTrigger;
int selTable;
+ int selVariable;
SimpleStringList indexNames;
SimpleStringList functionNames;
SimpleStringList schemaNames;
SimpleStringList schemaExcludeNames;
SimpleStringList triggerNames;
SimpleStringList tableNames;
+ SimpleStringList variableNames;
int useDB;
ConnParams cparams; /* parameters to use if useDB */
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 1d131e5a57d..f6acdf5a5e7 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -3133,6 +3133,14 @@ _tocEntryRequired(TocEntry *te, teSection curSection, ArchiveHandle *AH)
!simple_string_list_member(&ropt->triggerNames, te->tag))
return 0;
}
+ else if (strcmp(te->desc, "VARIABLE") == 0)
+ {
+ if (!ropt->selVariable)
+ return 0;
+ if (ropt->variableNames.head != NULL &&
+ !simple_string_list_member(&ropt->variableNames, te->tag))
+ return 0;
+ }
else
return 0;
}
@@ -3703,6 +3711,7 @@ _getObjectDescription(PQExpBuffer buf, const TocEntry *te)
strcmp(type, "TEXT SEARCH DICTIONARY") == 0 ||
strcmp(type, "TEXT SEARCH CONFIGURATION") == 0 ||
strcmp(type, "TYPE") == 0 ||
+ strcmp(type, "VARIABLE") == 0 ||
strcmp(type, "VIEW") == 0 ||
/* non-schema-specified objects */
strcmp(type, "DATABASE") == 0 ||
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 4ca34be230c..01d44361675 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -365,6 +365,7 @@ static void dumpPublication(Archive *fout, const PublicationInfo *pubinfo);
static void dumpPublicationTable(Archive *fout, const PublicationRelInfo *pubrinfo);
static void dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo);
static void dumpSubscriptionTable(Archive *fout, const SubRelInfo *subrinfo);
+static void dumpVariable(Archive *fout, const VariableInfo *varinfo);
static void dumpDatabase(Archive *fout);
static void dumpDatabaseConfig(Archive *AH, PQExpBuffer outbuf,
const char *dbname, Oid dboid);
@@ -5507,6 +5508,188 @@ get_next_possible_free_pg_type_oid(Archive *fout, PQExpBuffer upgrade_query)
return next_possible_free_oid;
}
+/*
+ * getVariables
+ * get information about variables
+ */
+void
+getVariables(Archive *fout)
+{
+ PQExpBuffer query;
+ PGresult *res;
+ VariableInfo *varinfo;
+ int i_tableoid;
+ int i_oid;
+ int i_varname;
+ int i_varnamespace;
+ int i_vartype;
+ int i_vartypname;
+ int i_varowner;
+ int i_varcollation;
+ int i_varacl;
+ int i_acldefault;
+ int i,
+ ntups;
+
+ if (fout->remoteVersion < 180000)
+ return;
+
+ query = createPQExpBuffer();
+
+ /* get the variables in current database */
+ appendPQExpBuffer(query,
+ "SELECT v.tableoid, v.oid, v.varname,\n"
+ " v.varnamespace, v.vartype,\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n"
+ " CASE WHEN v.varcollation <> t.typcollation "
+ " THEN v.varcollation\n"
+ " ELSE 0\n"
+ " END AS varcollation,\n"
+ " v.varowner, v.varacl,\n"
+ " acldefault('V', v.varowner) AS acldefault\n"
+ "FROM pg_catalog.pg_variable v\n"
+ "JOIN pg_catalog.pg_type t "
+ "ON (v.vartype = t.oid)");
+
+ res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK);
+
+ ntups = PQntuples(res);
+
+ i_tableoid = PQfnumber(res, "tableoid");
+ i_oid = PQfnumber(res, "oid");
+ i_varname = PQfnumber(res, "varname");
+ i_varnamespace = PQfnumber(res, "varnamespace");
+ i_vartype = PQfnumber(res, "vartype");
+ i_vartypname = PQfnumber(res, "vartypname");
+ i_varcollation = PQfnumber(res, "varcollation");
+
+ i_varowner = PQfnumber(res, "varowner");
+ i_varacl = PQfnumber(res, "varacl");
+ i_acldefault = PQfnumber(res, "acldefault");
+
+ varinfo = pg_malloc(ntups * sizeof(VariableInfo));
+
+ for (i = 0; i < ntups; i++)
+ {
+ TypeInfo *vtype;
+
+ varinfo[i].dobj.objType = DO_VARIABLE;
+ varinfo[i].dobj.catId.tableoid =
+ atooid(PQgetvalue(res, i, i_tableoid));
+ varinfo[i].dobj.catId.oid = atooid(PQgetvalue(res, i, i_oid));
+ AssignDumpId(&varinfo[i].dobj);
+ varinfo[i].dobj.name = pg_strdup(PQgetvalue(res, i, i_varname));
+ varinfo[i].dobj.namespace =
+ findNamespace(atooid(PQgetvalue(res, i, i_varnamespace)));
+
+ varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype));
+ varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname));
+ varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
+
+ varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
+ varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
+ varinfo[i].dacl.privtype = 0;
+ varinfo[i].dacl.initprivs = NULL;
+ varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner));
+
+ /* do not try to dump ACL if no ACL exists */
+ if (!PQgetisnull(res, i, i_varacl))
+ varinfo[i].dobj.components |= DUMP_COMPONENT_ACL;
+
+ if (strlen(varinfo[i].rolname) == 0)
+ pg_log_warning("owner of variable \"%s\" appears to be invalid",
+ varinfo[i].dobj.name);
+
+ /* decide whether we want to dump it */
+ selectDumpableObject(&(varinfo[i].dobj), fout);
+
+ vtype = findTypeByOid(varinfo[i].vartype);
+ addObjectDependency(&varinfo[i].dobj, vtype->dobj.dumpId);
+ }
+ PQclear(res);
+
+ destroyPQExpBuffer(query);
+}
+
+/*
+ * dumpVariable
+ * dump the definition of the given session variable
+ */
+static void
+dumpVariable(Archive *fout, const VariableInfo *varinfo)
+{
+ DumpOptions *dopt = fout->dopt;
+
+ PQExpBuffer delq;
+ PQExpBuffer query;
+ char *qualvarname;
+ const char *vartypname;
+ Oid varcollation;
+
+ /* skip if not to be dumped */
+ if (!varinfo->dobj.dump || !dopt->dumpSchema)
+ return;
+
+ delq = createPQExpBuffer();
+ query = createPQExpBuffer();
+
+ qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
+ vartypname = varinfo->vartypname;
+ varcollation = varinfo->varcollation;
+
+ appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
+ qualvarname);
+
+ appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s",
+ qualvarname, vartypname);
+
+ if (OidIsValid(varcollation))
+ {
+ CollInfo *coll;
+
+ coll = findCollationByOid(varcollation);
+ if (coll)
+ appendPQExpBuffer(query, " COLLATE %s",
+ fmtQualifiedDumpable(coll));
+ }
+
+ appendPQExpBuffer(query, ";\n");
+
+ if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
+ ArchiveEntry(fout, varinfo->dobj.catId, varinfo->dobj.dumpId,
+ ARCHIVE_OPTS(.tag = varinfo->dobj.name,
+ .namespace = varinfo->dobj.namespace->dobj.name,
+ .owner = varinfo->rolname,
+ .description = "VARIABLE",
+ .section = SECTION_PRE_DATA,
+ .createStmt = query->data,
+ .dropStmt = delq->data));
+
+ /* dump comment if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_COMMENT)
+ dumpComment(fout, "VARIABLE", qualvarname,
+ NULL, varinfo->rolname,
+ varinfo->dobj.catId, 0, varinfo->dobj.dumpId);
+
+ /* dump ACL if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_ACL)
+ {
+ char *qvarname = pg_strdup(fmtId(varinfo->dobj.name));
+
+ dumpACL(fout, varinfo->dobj.dumpId, InvalidDumpId, "VARIABLE",
+ qvarname, NULL,
+ varinfo->dobj.namespace->dobj.name, NULL, varinfo->rolname,
+ &varinfo->dacl);
+
+ free(qvarname);
+ }
+
+ destroyPQExpBuffer(delq);
+ destroyPQExpBuffer(query);
+
+ free(qualvarname);
+}
+
static void
binary_upgrade_set_type_oids_by_type_oid(Archive *fout,
PQExpBuffer upgrade_buffer,
@@ -11234,6 +11417,9 @@ dumpDumpableObject(Archive *fout, DumpableObject *dobj)
case DO_REL_STATS:
dumpRelationStats(fout, (const RelStatsInfo *) dobj);
break;
+ case DO_VARIABLE:
+ dumpVariable(fout, (VariableInfo *) dobj);
+ break;
case DO_PRE_DATA_BOUNDARY:
case DO_POST_DATA_BOUNDARY:
/* never dumped, nothing to do */
@@ -15685,6 +15871,9 @@ dumpDefaultACL(Archive *fout, const DefaultACLInfo *daclinfo)
case DEFACLOBJ_NAMESPACE:
type = "SCHEMAS";
break;
+ case DEFACLOBJ_VARIABLE:
+ type = "VARIABLES";
+ break;
default:
/* shouldn't get here */
pg_fatal("unrecognized object type in default privileges: %d",
@@ -19407,6 +19596,7 @@ addBoundaryDependencies(DumpableObject **dobjs, int numObjs,
case DO_CONVERSION:
case DO_TABLE:
case DO_TABLE_ATTACH:
+ case DO_VARIABLE:
case DO_ATTRDEF:
case DO_PROCLANG:
case DO_CAST:
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index e6f0f86a459..0821066b3b0 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -53,6 +53,7 @@ typedef enum
DO_TABLE,
DO_TABLE_ATTACH,
DO_ATTRDEF,
+ DO_VARIABLE,
DO_INDEX,
DO_INDEX_ATTACH,
DO_STATSEXT,
@@ -732,6 +733,19 @@ typedef struct _SubRelInfo
char *srsublsn;
} SubRelInfo;
+/*
+ * The VariableInfo struct is used to represent session variables
+ */
+typedef struct _VariableInfo
+{
+ DumpableObject dobj;
+ DumpableAcl dacl;
+ Oid vartype;
+ char *vartypname;
+ Oid varcollation;
+ const char *rolname; /* name of owner, or empty string */
+} VariableInfo;
+
/*
* common utility functions
*/
@@ -815,5 +829,6 @@ extern void getPublicationTables(Archive *fout, TableInfo tblinfo[],
int numTables);
extern void getSubscriptions(Archive *fout);
extern void getSubscriptionTables(Archive *fout);
+extern void getVariables(Archive *fout);
#endif /* PG_DUMP_H */
diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c
index 0b0977788f1..b34f3418f64 100644
--- a/src/bin/pg_dump/pg_dump_sort.c
+++ b/src/bin/pg_dump/pg_dump_sort.c
@@ -77,6 +77,7 @@ enum dbObjectTypePriorities
PRIO_DUMMY_TYPE,
PRIO_ATTRDEF,
PRIO_LARGE_OBJECT,
+ PRIO_VARIABLE,
PRIO_PRE_DATA_BOUNDARY, /* boundary! */
PRIO_TABLE_DATA,
PRIO_SEQUENCE_SET,
@@ -119,6 +120,7 @@ static const int dbObjectTypePriority[] =
[DO_TABLE] = PRIO_TABLE,
[DO_TABLE_ATTACH] = PRIO_TABLE_ATTACH,
[DO_ATTRDEF] = PRIO_ATTRDEF,
+ [DO_VARIABLE] = PRIO_VARIABLE,
[DO_INDEX] = PRIO_INDEX,
[DO_INDEX_ATTACH] = PRIO_INDEX_ATTACH,
[DO_STATSEXT] = PRIO_STATSEXT,
@@ -1533,6 +1535,11 @@ describeDumpableObject(DumpableObject *obj, char *buf, int bufsize)
"RELATION STATISTICS FOR %s (ID %d OID %u)",
obj->name, obj->dumpId, obj->catId.oid);
return;
+ case DO_VARIABLE:
+ snprintf(buf, bufsize,
+ "VARIABLE %s (ID %d OID %u)",
+ obj->name, obj->dumpId, obj->catId.oid);
+ return;
}
/* shouldn't get here */
snprintf(buf, bufsize,
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 576326daec7..1c4e79b6a39 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -901,6 +901,16 @@ my %tests = (
unlike => { no_privs => 1, },
},
+ 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC'
+ => {
+ create_order => 56,
+ create_sql => 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;',
+ regexp => qr/^
+ \QALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;\E/xm,
+ like => { %full_runs, section_post_data => 1, },
+ unlike => { no_privs => 1, },
+ },
+
'ALTER ROLE regress_dump_test_role' => {
regexp => qr/^
\QALTER ROLE regress_dump_test_role WITH \E
@@ -1797,6 +1807,23 @@ my %tests = (
},
},
+ 'COMMENT ON VARIABLE dump_test.variable1' => {
+ create_order => 71,
+ create_sql => 'COMMENT ON VARIABLE dump_test.variable1
+ IS \'comment on variable\';',
+ regexp =>
+ qr/^\QCOMMENT ON VARIABLE dump_test.variable1 IS 'comment on variable';\E/m,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'COPY test_table' => {
create_order => 4,
create_sql => 'INSERT INTO dump_test.test_table (col1) '
@@ -4105,6 +4132,24 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable1 AS integer;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable1 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
@@ -4569,6 +4614,25 @@ my %tests = (
like => {},
},
+ 'GRANT SELECT ON VARIABLE dump_test.variable1' => {
+ create_order => 73,
+ create_sql =>
+ 'GRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;',
+ regexp => qr/^
+ \QGRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;\E
+ /xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ no_privs => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'REFRESH MATERIALIZED VIEW matview' => {
regexp => qr/^\QREFRESH MATERIALIZED VIEW dump_test.matview;\E/m,
like =>
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index a8a13c2b88b..cfcaa66f57d 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -1246,6 +1246,9 @@ exec_command_d(PsqlScanState scan_state, bool active_branch, const char *cmd)
break;
}
break;
+ case 'V': /* Variables */
+ success = listVariables(pattern, show_verbose);
+ break;
case 'x': /* Extensions */
if (show_verbose)
success = listExtensionContents(pattern);
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index bf565afcc4e..44949497a0b 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -1222,7 +1222,7 @@ listDefaultACLs(const char *pattern)
printfPQExpBuffer(&buf,
"SELECT pg_catalog.pg_get_userbyid(d.defaclrole) AS \"%s\",\n"
" n.nspname AS \"%s\",\n"
- " CASE d.defaclobjtype WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
+ " CASE d.defaclobjtype WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
" ",
gettext_noop("Owner"),
gettext_noop("Schema"),
@@ -1236,6 +1236,8 @@ listDefaultACLs(const char *pattern)
gettext_noop("type"),
DEFACLOBJ_NAMESPACE,
gettext_noop("schema"),
+ DEFACLOBJ_VARIABLE,
+ gettext_noop("session variable"),
gettext_noop("Type"));
printACLColumn(&buf, "d.defaclacl");
@@ -5318,6 +5320,102 @@ error_return:
return false;
}
+/*
+ * \dV
+ *
+ * listVariables()
+ */
+bool
+listVariables(const char *pattern, bool verbose)
+{
+ PQExpBufferData buf;
+ PGresult *res;
+ printQueryOpt myopt = pset.popt;
+ static const bool translate_columns[] = {false, false, false, false, false, false, false};
+
+ if (pset.sversion < 180000)
+ {
+ char sverbuf[32];
+
+ pg_log_error("The server (version %s) does not support session variables.",
+ formatPGVersionNumber(pset.sversion, false,
+ sverbuf, sizeof(sverbuf)));
+ return true;
+ }
+
+ initPQExpBuffer(&buf);
+
+ printfPQExpBuffer(&buf,
+ "SELECT n.nspname as \"%s\",\n"
+ " v.varname as \"%s\",\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n"
+ " (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
+ " WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
+ " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n",
+ gettext_noop("Schema"),
+ gettext_noop("Name"),
+ gettext_noop("Type"),
+ gettext_noop("Collation"),
+ gettext_noop("Owner"));
+
+ if (verbose)
+ {
+ appendPQExpBufferStr(&buf, ",\n ");
+ printACLColumn(&buf, "v.varacl");
+ appendPQExpBuffer(&buf,
+ ",\n pg_catalog.obj_description(v.oid, 'pg_variable') AS \"%s\"",
+ gettext_noop("Description"));
+ }
+
+ appendPQExpBufferStr(&buf,
+ "\nFROM pg_catalog.pg_variable v"
+ "\n LEFT JOIN pg_catalog.pg_namespace n ON n.oid = v.varnamespace");
+
+ appendPQExpBufferStr(&buf, "\nWHERE true\n");
+ if (!pattern)
+ appendPQExpBufferStr(&buf, " AND n.nspname <> 'pg_catalog'\n"
+ " AND n.nspname <> 'information_schema'\n");
+
+ if (!validateSQLNamePattern(&buf, pattern, true, false,
+ "n.nspname", "v.varname", NULL,
+ "pg_catalog.pg_variable_is_visible(v.oid)",
+ NULL, 3))
+ return false;
+
+ appendPQExpBufferStr(&buf, "ORDER BY 1,2;");
+
+ res = PSQLexec(buf.data);
+ termPQExpBuffer(&buf);
+ if (!res)
+ return false;
+
+ /*
+ * Most functions in this file are content to print an empty table when
+ * there are no matching objects. We intentionally deviate from that
+ * here, but only in !quiet mode, for historical reasons.
+ */
+ if (PQntuples(res) == 0 && !pset.quiet)
+ {
+ if (pattern)
+ pg_log_error("Did not find any session variable named \"%s\".",
+ pattern);
+ else
+ pg_log_error("Did not find any session variables.");
+ }
+ else
+ {
+ myopt.nullPrint = NULL;
+ myopt.title = _("List of variables");
+ myopt.translate_header = true;
+ myopt.translate_columns = translate_columns;
+ myopt.n_translate_columns = lengthof(translate_columns);
+
+ printQuery(res, &myopt, pset.queryFout, false, pset.logfile);
+ }
+
+ PQclear(res);
+ return true;
+}
/*
* \dFp
diff --git a/src/bin/psql/describe.h b/src/bin/psql/describe.h
index 18ecaa60949..55ced4aab7b 100644
--- a/src/bin/psql/describe.h
+++ b/src/bin/psql/describe.h
@@ -149,4 +149,7 @@ extern bool listOpFamilyFunctions(const char *access_method_pattern,
/* \dl or \lo_list */
extern bool listLargeObjects(bool verbose);
+/* \dV */
+extern bool listVariables(const char *pattern, bool varbose);
+
#endif /* DESCRIBE_H */
diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index fe96e3e1de9..889f6cb2dc4 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -274,6 +274,7 @@ slashUsage(unsigned short int pager)
HELP0(" \\dT[Sx+] [PATTERN] list data types\n");
HELP0(" \\du[Sx+] [PATTERN] list roles\n");
HELP0(" \\dv[Sx+] [PATTERN] list views\n");
+ HELP0(" \\dV[x+] [PATTERN] list session variables\n");
HELP0(" \\dx[x+] [PATTERN] list extensions\n");
HELP0(" \\dX[x] [PATTERN] list extended statistics\n");
HELP0(" \\dy[x+] [PATTERN] list event triggers\n");
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 98951aef82c..78c0544e516 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -970,6 +970,13 @@ static const SchemaQuery Query_for_trigger_of_table = {
.refnamespace = "c1.relnamespace",
};
+static const SchemaQuery Query_for_list_of_variables = {
+ .min_server_version = 180000,
+ .catname = "pg_catalog.pg_variable v",
+ .viscondition = "pg_catalog.pg_variable_is_visible(v.oid)",
+ .namespace = "v.varnamespace",
+ .result = "v.varname",
+};
/*
* Queries to get lists of names of various kinds of things, possibly
@@ -1318,6 +1325,7 @@ static const pgsql_thing_t words_after_create[] = {
* TABLE ... */
{"USER", Query_for_list_of_roles, NULL, NULL, Keywords_for_user_thing},
{"USER MAPPING FOR", NULL, NULL, NULL},
+ {"VARIABLE", NULL, NULL, &Query_for_list_of_variables},
{"VIEW", NULL, NULL, &Query_for_list_of_views},
{NULL} /* end of list */
};
@@ -1883,7 +1891,7 @@ psql_completion(const char *text, int start, int end)
"\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL",
"\\dm", "\\dn", "\\do", "\\dO", "\\dp", "\\dP", "\\dPi", "\\dPt",
"\\drds", "\\drg", "\\dRs", "\\dRp", "\\ds",
- "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy",
+ "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy", "\\dV",
"\\echo", "\\edit", "\\ef", "\\elif", "\\else", "\\encoding",
"\\endif", "\\endpipeline", "\\errverbose", "\\ev",
"\\f", "\\flush", "\\flushrequest",
@@ -2586,6 +2594,9 @@ match_previous_words(int pattern_id,
"ALL");
else if (Matches("ALTER", "SYSTEM", "SET", MatchAny))
COMPLETE_WITH("TO");
+ /* ALTER VARIABLE <name> */
+ else if (Matches("ALTER", "VARIABLE", MatchAny))
+ COMPLETE_WITH("OWNER TO", "RENAME TO", "SET SCHEMA");
/* ALTER VIEW <name> */
else if (Matches("ALTER", "VIEW", MatchAny))
COMPLETE_WITH("ALTER COLUMN", "OWNER TO", "RENAME", "RESET", "SET");
@@ -3169,7 +3180,7 @@ match_previous_words(int pattern_id,
"ROUTINE", "RULE", "SCHEMA", "SEQUENCE", "SERVER",
"STATISTICS", "SUBSCRIPTION", "TABLE",
"TABLESPACE", "TEXT SEARCH", "TRANSFORM FOR",
- "TRIGGER", "TYPE", "VIEW");
+ "TRIGGER", "TYPE", "VARIABLE", "VIEW");
else if (Matches("COMMENT", "ON", "ACCESS", "METHOD"))
COMPLETE_WITH_QUERY(Query_for_list_of_access_methods);
else if (Matches("COMMENT", "ON", "CONSTRAINT"))
@@ -3979,6 +3990,13 @@ match_previous_words(int pattern_id,
else if (TailMatches("=", MatchAnyExcept("*)")))
COMPLETE_WITH(",", ")");
}
+/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
+ /* Complete CREATE VARIABLE <name> with AS */
+ else if (TailMatches("CREATE", "VARIABLE", MatchAny))
+ COMPLETE_WITH("AS");
+ else if (TailMatches("VARIABLE", MatchAny, "AS"))
+ /* Complete CREATE VARIABLE <name> with AS types */
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
/* CREATE VIEW --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE [ OR REPLACE ] VIEW <name> with AS or WITH */
@@ -4256,6 +4274,12 @@ match_previous_words(int pattern_id,
else if (Matches("DROP", "TRANSFORM", "FOR", MatchAny, "LANGUAGE", MatchAny))
COMPLETE_WITH("CASCADE", "RESTRICT");
+ /* DROP VARIABLE */
+ else if (Matches("DROP", "VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ else if (Matches("DROP", "VARIABLE", MatchAny))
+ COMPLETE_WITH("CASCADE", "RESTRICT");
+
/* EXECUTE */
else if (Matches("EXECUTE"))
COMPLETE_WITH_QUERY(Query_for_list_of_prepared_statements);
@@ -4457,7 +4481,7 @@ match_previous_words(int pattern_id,
* objects supported.
*/
if (HeadMatches("ALTER", "DEFAULT", "PRIVILEGES"))
- COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS");
+ COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS", "VARIABLES");
else
COMPLETE_WITH_SCHEMA_QUERY_PLUS(Query_for_list_of_grantables,
"ALL FUNCTIONS IN SCHEMA",
@@ -4465,6 +4489,7 @@ match_previous_words(int pattern_id,
"ALL ROUTINES IN SCHEMA",
"ALL SEQUENCES IN SCHEMA",
"ALL TABLES IN SCHEMA",
+ "ALL VARIABLES IN SCHEMA",
"DATABASE",
"DOMAIN",
"FOREIGN DATA WRAPPER",
@@ -4479,7 +4504,8 @@ match_previous_words(int pattern_id,
"SEQUENCE",
"TABLE",
"TABLESPACE",
- "TYPE");
+ "TYPE",
+ "VARIABLE");
}
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "ALL") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "ALL"))
@@ -4487,7 +4513,8 @@ match_previous_words(int pattern_id,
"PROCEDURES IN SCHEMA",
"ROUTINES IN SCHEMA",
"SEQUENCES IN SCHEMA",
- "TABLES IN SCHEMA");
+ "TABLES IN SCHEMA",
+ "VARIABLES IN SCHEMA");
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "FOREIGN") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "FOREIGN"))
COMPLETE_WITH("DATA WRAPPER", "SERVER");
@@ -4523,6 +4550,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_tablespaces);
else if (TailMatches("TYPE"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
+ else if (TailMatches("VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatches("GRANT", MatchAny, MatchAny, MatchAny))
COMPLETE_WITH("TO");
else
@@ -4825,7 +4854,7 @@ match_previous_words(int pattern_id,
/* PREPARE xx AS */
else if (Matches("PREPARE", MatchAny, "AS"))
- COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM");
+ COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM", "LET");
/*
* PREPARE TRANSACTION is missing on purpose. It's intended for transaction
@@ -5314,6 +5343,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_roles);
else if (TailMatchesCS("\\dv*"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_views);
+ else if (TailMatchesCS("\\dV*"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatchesCS("\\dx*"))
COMPLETE_WITH_QUERY(Query_for_list_of_extensions);
else if (TailMatchesCS("\\dX*"))
diff --git a/src/include/catalog/Makefile b/src/include/catalog/Makefile
index 2bbc7805fe3..f98760de635 100644
--- a/src/include/catalog/Makefile
+++ b/src/include/catalog/Makefile
@@ -81,7 +81,8 @@ CATALOG_HEADERS := \
pg_publication_namespace.h \
pg_publication_rel.h \
pg_subscription.h \
- pg_subscription_rel.h
+ pg_subscription_rel.h \
+ pg_variable.h
GENERATED_HEADERS := $(CATALOG_HEADERS:%.h=%_d.h)
diff --git a/src/include/catalog/meson.build b/src/include/catalog/meson.build
index ec1cf467f6f..81398efa7c9 100644
--- a/src/include/catalog/meson.build
+++ b/src/include/catalog/meson.build
@@ -69,6 +69,7 @@ catalog_headers = [
'pg_publication_rel.h',
'pg_subscription.h',
'pg_subscription_rel.h',
+ 'pg_variable.h',
]
# The .dat files we need can just be listed alphabetically.
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index 8c7ccc69a3c..bdac0c13bec 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -97,6 +97,8 @@ extern Oid TypenameGetTypid(const char *typname);
extern Oid TypenameGetTypidExtended(const char *typname, bool temp_ok);
extern bool TypeIsVisible(Oid typid);
+extern bool VariableIsVisible(Oid varid);
+
extern FuncCandidateList FuncnameGetCandidates(List *names,
int nargs, List *argnames,
bool expand_variadic,
@@ -169,6 +171,10 @@ extern SearchPathMatcher *GetSearchPathMatcher(MemoryContext context);
extern SearchPathMatcher *CopySearchPathMatcher(SearchPathMatcher *path);
extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
+extern List *NamesFromList(List *names);
+extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
+extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
extern Oid FindDefaultConversionProc(int32 for_encoding, int32 to_encoding);
diff --git a/src/include/catalog/pg_default_acl.h b/src/include/catalog/pg_default_acl.h
index 728024b1fa7..5f94424a684 100644
--- a/src/include/catalog/pg_default_acl.h
+++ b/src/include/catalog/pg_default_acl.h
@@ -68,6 +68,7 @@ MAKE_SYSCACHE(DEFACLROLENSPOBJ, pg_default_acl_role_nsp_obj_index, 8);
#define DEFACLOBJ_FUNCTION 'f' /* function */
#define DEFACLOBJ_TYPE 'T' /* type */
#define DEFACLOBJ_NAMESPACE 'n' /* namespace */
+#define DEFACLOBJ_VARIABLE 'V' /* variable */
#endif /* EXPOSE_TO_CLIENT_CODE */
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 6b57b7e18d9..fa29734138f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5445,6 +5445,26 @@
prorettype => 'bool', proargtypes => 'oid oid text',
prosrc => 'has_largeobject_privilege_id_id' },
+{ oid => '9613', descr => 'user privilege on session variable by username, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name text text',
+ prosrc => 'has_session_variable_privilege_name_name' },
+{ oid => '9614', descr => 'user privilege on session variable by username, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name oid text', prosrc => 'has_session_variable_privilege_name_id' },
+{ oid => '9615', descr => 'user privilege on session variable by user oid, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text text', prosrc => 'has_session_variable_privilege_id_name' },
+{ oid => '9616', descr => 'user privilege on session variable by user oid, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid oid text', prosrc => 'has_session_variable_privilege_id_id' },
+{ oid => '9617', descr => 'current user privilege on session variable by seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'text text', prosrc => 'has_session_variable_privilege_name' },
+{ oid => '9618', descr => 'current user privilege on session variable by seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text', prosrc => 'has_session_variable_privilege_id' },
+
{ oid => '3355', descr => 'I/O',
proname => 'pg_ndistinct_in', prorettype => 'pg_ndistinct',
proargtypes => 'cstring', prosrc => 'pg_ndistinct_in' },
@@ -6652,6 +6672,9 @@
proname => 'pg_collation_is_visible', procost => '10', provolatile => 's',
prorettype => 'bool', proargtypes => 'oid',
prosrc => 'pg_collation_is_visible' },
+{ oid => '9999', descr => 'is session variable visible in search path?',
+ proname => 'pg_variable_is_visible', procost => '10', provolatile => 's',
+ prorettype => 'bool', proargtypes => 'oid', prosrc => 'pg_variable_is_visible' },
{ oid => '2854', descr => 'get OID of current session\'s temp schema, if any',
proname => 'pg_my_temp_schema', provolatile => 's', proparallel => 'r',
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
new file mode 100644
index 00000000000..3d3c6eb24b5
--- /dev/null
+++ b/src/include/catalog/pg_variable.h
@@ -0,0 +1,81 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.h
+ * definition of session variables system catalog (pg_variables)
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/catalog/pg_variable.h
+ *
+ * NOTES
+ * The Catalog.pm module reads this file and derives schema
+ * information.
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_VARIABLE_H
+#define PG_VARIABLE_H
+
+#include "catalog/genbki.h"
+#include "catalog/objectaddress.h"
+#include "catalog/pg_variable_d.h"
+#include "utils/acl.h"
+
+/* ----------------
+ * pg_variable definition. cpp turns this into
+ * typedef struct FormData_pg_variable
+ * ----------------
+ */
+CATALOG(pg_variable,9222,VariableRelationId)
+{
+ Oid oid; /* oid */
+
+ /* OID of entry in pg_type for variable's type */
+ Oid vartype BKI_LOOKUP(pg_type);
+
+ /* variable name */
+ NameData varname;
+
+ /* OID of namespace containing variable class */
+ Oid varnamespace BKI_LOOKUP(pg_namespace);
+
+ /* variable owner */
+ Oid varowner BKI_LOOKUP(pg_authid);
+
+ /* typmod for variable's type */
+ int32 vartypmod BKI_DEFAULT(-1);
+
+ /* variable collation */
+ Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation);
+
+
+#ifdef CATALOG_VARLEN /* variable-length fields start here */
+
+ /* access permissions */
+ aclitem varacl[1] BKI_DEFAULT(_null_);
+
+#endif
+} FormData_pg_variable;
+
+/* ----------------
+ * Form_pg_variable corresponds to a pointer to a tuple with
+ * the format of the pg_variable relation.
+ * ----------------
+ */
+typedef FormData_pg_variable *Form_pg_variable;
+
+DECLARE_TOAST(pg_variable, 9223, 9224);
+
+DECLARE_UNIQUE_INDEX_PKEY(pg_variable_oid_index, 9225, VariableOidIndexId, pg_variable, btree(oid oid_ops));
+DECLARE_UNIQUE_INDEX(pg_variable_varname_nsp_index, 9226, VariableNameNspIndexId, pg_variable, btree(varname name_ops, varnamespace oid_ops));
+
+extern ObjectAddress CreateVariable(ParseState *pstate,
+ CreateSessionVarStmt *stmt);
+extern void DropVariableById(Oid varid);
+
+MAKE_SYSCACHE(VARIABLENAMENSP, pg_variable_varname_nsp_index, 8);
+MAKE_SYSCACHE(VARIABLEOID, pg_variable_oid_index, 8);
+
+#endif /* PG_VARIABLE_H */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index df331b1c0d9..3decee1a98f 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2365,6 +2365,7 @@ typedef enum ObjectType
OBJECT_TSTEMPLATE,
OBJECT_TYPE,
OBJECT_USER_MAPPING,
+ OBJECT_VARIABLE,
OBJECT_VIEW,
} ObjectType;
@@ -3513,6 +3514,21 @@ typedef struct AlterStatsStmt
bool missing_ok; /* skip error if statistics object is missing */
} AlterStatsStmt;
+
+/* ----------------------
+ * {Create|Alter} VARIABLE Statement
+ * ----------------------
+ */
+typedef struct CreateSessionVarStmt
+{
+ NodeTag type;
+ RangeVar *variable; /* the variable to create */
+ TypeName *typeName; /* the type of variable */
+ CollateClause *collClause;
+ bool if_not_exists; /* do nothing if it already exists */
+} CreateSessionVarStmt;
+
+
/* ----------------------
* Create Function Statement
* ----------------------
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 40cf090ce61..793ace526df 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -485,6 +485,8 @@ PG_KEYWORD("validator", VALIDATOR, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("value", VALUE_P, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("values", VALUES, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("varchar", VARCHAR, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variable", VARIABLE, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variables", VARIABLES, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("variadic", VARIADIC, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("varying", VARYING, UNRESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("verbose", VERBOSE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index d250a714d59..ea86954dded 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -68,6 +68,7 @@ PG_CMDTAG(CMDTAG_ALTER_TRANSFORM, "ALTER TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TRIGGER, "ALTER TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TYPE, "ALTER TYPE", true, true, false)
PG_CMDTAG(CMDTAG_ALTER_USER_MAPPING, "ALTER USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_ALTER_VARIABLE, "ALTER VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_VIEW, "ALTER VIEW", true, false, false)
PG_CMDTAG(CMDTAG_ANALYZE, "ANALYZE", false, false, false)
PG_CMDTAG(CMDTAG_BEGIN, "BEGIN", false, false, false)
@@ -123,6 +124,7 @@ PG_CMDTAG(CMDTAG_CREATE_TRANSFORM, "CREATE TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TRIGGER, "CREATE TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TYPE, "CREATE TYPE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_USER_MAPPING, "CREATE USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_CREATE_VARIABLE, "CREATE VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_VIEW, "CREATE VIEW", true, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE, "DEALLOCATE", false, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE_ALL, "DEALLOCATE ALL", false, false, false)
@@ -175,6 +177,7 @@ PG_CMDTAG(CMDTAG_DROP_TRANSFORM, "DROP TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TRIGGER, "DROP TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TYPE, "DROP TYPE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_USER_MAPPING, "DROP USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_DROP_VARIABLE, "DROP VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_VIEW, "DROP VIEW", true, false, false)
PG_CMDTAG(CMDTAG_EXECUTE, "EXECUTE", false, false, false)
PG_CMDTAG(CMDTAG_EXPLAIN, "EXPLAIN", false, false, false)
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index 01ae5b719fd..5e1a8a82e90 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -169,6 +169,7 @@ typedef struct ArrayType Acl;
#define ACL_ALL_RIGHTS_SCHEMA (ACL_USAGE|ACL_CREATE)
#define ACL_ALL_RIGHTS_TABLESPACE (ACL_CREATE)
#define ACL_ALL_RIGHTS_TYPE (ACL_USAGE)
+#define ACL_ALL_RIGHTS_VARIABLE (ACL_SELECT|ACL_UPDATE)
/* operation codes for pg_*_aclmask */
typedef enum
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index d42380a0d46..967d2ac3522 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -139,6 +139,7 @@ extern char get_func_prokind(Oid funcid);
extern bool get_func_leakproof(Oid funcid);
extern RegProcedure get_func_support(Oid funcid);
extern Oid get_relname_relid(const char *relname, Oid relnamespace);
+extern Oid get_varname_varid(const char *varname, Oid varnamespace);
extern char *get_rel_name(Oid relid);
extern Oid get_rel_namespace(Oid relid);
extern Oid get_rel_type_id(Oid relid);
@@ -211,6 +212,14 @@ extern char *get_publication_name(Oid pubid, bool missing_ok);
extern Oid get_subscription_oid(const char *subname, bool missing_ok);
extern char *get_subscription_name(Oid subid, bool missing_ok);
+extern char *get_session_variable_name(Oid varid);
+extern Oid get_session_variable_namespace(Oid varid);
+extern Oid get_session_variable_type(Oid varid);
+extern void get_session_variable_type_typmod_collid(Oid varid,
+ Oid *typid,
+ int32 *typmod,
+ Oid *collid);
+
#define type_is_array(typid) (get_element_type(typid) != InvalidOid)
/* type_is_array_domain accepts both plain arrays and domains over arrays */
#define type_is_array_domain(typid) (get_base_element_type(typid) != InvalidOid)
diff --git a/src/test/regress/expected/dependency.out b/src/test/regress/expected/dependency.out
index 75a078ada9e..cd8e4412fa9 100644
--- a/src/test/regress/expected/dependency.out
+++ b/src/test/regress/expected/dependency.out
@@ -151,3 +151,20 @@ owner of type deptest_t
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+-- should fail
+DROP DOMAIN vardomain;
+ERROR: cannot drop type vardomain because other objects depend on it
+DETAIL: column c of composite type vartype depends on type vardomain
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP TYPE vartype;
+ERROR: cannot drop type vartype because other objects depend on it
+DETAIL: session variable var1 depends on type vartype
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/expected/oidjoins.out b/src/test/regress/expected/oidjoins.out
index 215eb899be3..d9953321402 100644
--- a/src/test/regress/expected/oidjoins.out
+++ b/src/test/regress/expected/oidjoins.out
@@ -266,3 +266,7 @@ NOTICE: checking pg_subscription {subdbid} => pg_database {oid}
NOTICE: checking pg_subscription {subowner} => pg_authid {oid}
NOTICE: checking pg_subscription_rel {srsubid} => pg_subscription {oid}
NOTICE: checking pg_subscription_rel {srrelid} => pg_class {oid}
+NOTICE: checking pg_variable {vartype} => pg_type {oid}
+NOTICE: checking pg_variable {varnamespace} => pg_namespace {oid}
+NOTICE: checking pg_variable {varowner} => pg_authid {oid}
+NOTICE: checking pg_variable {varcollation} => pg_collation {oid}
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index b1d12585eae..aeb23612d2d 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6022,6 +6022,30 @@ COMMIT;
# final ON_ERROR_ROLLBACK: off
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | |
+(1 row)
+
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | =r/regress_variable_owner |
+(1 row)
+
+DROP VARIABLE var1;
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
-- check describing invalid multipart names
\dA regression.heap
improper qualified name (too many dotted names): regression.heap
@@ -6243,6 +6267,12 @@ cross-database references are not implemented: nonesuch.public.func_deps_stat
improper qualified name (too many dotted names): regression.myevt
\dy nonesuch.myevt
improper qualified name (too many dotted names): nonesuch.myevt
+\dV host.regression.public.var
+improper qualified name (too many dotted names): host.regression.public.var
+\dV regression|mydb.public.var
+cross-database references are not implemented: regression|mydb.public.var
+\dV nonesuch.public.var
+cross-database references are not implemented: nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
List of access methods
@@ -6477,6 +6507,12 @@ List of schemas
------+-------+-------+---------+----------+------
(0 rows)
+\dV "no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
improper qualified name (too many dotted names): "no.such.schema"."no.such.access.method"
@@ -6646,6 +6682,12 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
List of tables
@@ -6779,6 +6821,12 @@ List of text search templates
--------+------+------------+-----------+--------------+-----
(0 rows)
+\dV regression."no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -6826,6 +6874,8 @@ cross-database references are not implemented: "no.such.database"."no.such.schem
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
+cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
CREATE ROLE regress_du_role1;
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
new file mode 100644
index 00000000000..c36660ce6d3
--- /dev/null
+++ b/src/test/regress/expected/session_variables.out
@@ -0,0 +1,433 @@
+CREATE ROLE regress_variable_owner;
+SET log_statement TO ddl;
+-- should be ok
+CREATE VARIABLE var1 AS int;
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+ERROR: session variable cannot be pseudo-type anyelement
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+NOTICE: session variable "var2" does not exist, skipping
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+NOTICE: session variable "var1" already exists, skipping
+-- should fail
+CREATE VARIABLE var1 AS int;
+ERROR: session variable "var1" already exists
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TABLE t1;
+ERROR: cannot drop table t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+ERROR: cannot alter table "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TABLE t1;
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TYPE t1;
+ERROR: cannot drop type t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+ERROR: cannot alter type "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TYPE t1;
+SET log_statement TO default;
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+CREATE VARIABLE var1 AS testvar_domain;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter domain "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS testvar_type;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter type "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+NOTICE: NORMAL: orig=t normal=f istemp=f type=session variable identity=public.var1 name={public,var1} args={}
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+ obj_description
+-----------------------
+ some variable comment
+(1 row)
+
+DROP VARIABLE var1;
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+ varname | descr | type | object_names | object_args | ident
+---------------+-----------------------------------------+------------------+--------------------------+-------------+--------------------------------------------------------------------
+ svartest_var1 | session variable vartest1.svartest_var1 | session variable | {vartest1,svartest_var1} | {} | ("session variable",vartest1,svartest_var1,vartest1.svartest_var1)
+ svartest_var1 | session variable vartest2.svartest_var1 | session variable | {vartest2,svartest_var1} | {} | ("session variable",vartest2,svartest_var1,vartest2.svartest_var1)
+(2 rows)
+
+DROP SCHEMA vartest1 CASCADE;
+NOTICE: drop cascades to session variable vartest1.svartest_var1
+DROP SCHEMA vartest2 CASCADE;
+NOTICE: drop cascades to session variable vartest2.svartest_var1
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE ROLE regress_variable_reader;
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+DROP VARIABLE public.varxx;
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE public.var1 AS int;
+SET search_path TO public;
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+SET ROLE TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+--
+-- end of function has_session_variable_privilege tests.
+--
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+DROP VARIABLE public.var1;
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+DROP ROLE regress_variable_owner;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 0a35f2f8f6a..66e5f9f56bd 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -111,7 +111,7 @@ test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath sqljson
# NB: temp.sql does reconnects which transiently use 2 connections,
# so keep this parallel group to at most 19 tests
# ----------
-test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml
+test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml session_variables
# ----------
# Another group of parallel tests
diff --git a/src/test/regress/sql/dependency.sql b/src/test/regress/sql/dependency.sql
index 8d74ed7122c..6c18b7f840a 100644
--- a/src/test/regress/sql/dependency.sql
+++ b/src/test/regress/sql/dependency.sql
@@ -114,3 +114,17 @@ DROP USER regress_dep_user2;
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+
+-- should fail
+DROP DOMAIN vardomain;
+DROP TYPE vartype;
+
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index 1a8a83462f0..b567ee1eee2 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -1643,6 +1643,19 @@ COMMIT;
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+DROP VARIABLE var1;
+
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
+
-- check describing invalid multipart names
\dA regression.heap
\dA nonesuch.heap
@@ -1754,6 +1767,9 @@ DROP FUNCTION psql_error;
\dX nonesuch.public.func_deps_stat
\dy regression.myevt
\dy nonesuch.myevt
+\dV host.regression.public.var
+\dV regression|mydb.public.var
+\dV nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
@@ -1795,6 +1811,8 @@ DROP FUNCTION psql_error;
\dx "no.such.installed.extension"
\dX "no.such.extended.statistics"
\dy "no.such.event.trigger"
+\dV "no.such.variable"
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
@@ -1835,6 +1853,7 @@ DROP FUNCTION psql_error;
\dx "no.such.schema"."no.such.installed.extension"
\dX "no.such.schema"."no.such.extended.statistics"
\dy "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
@@ -1859,6 +1878,7 @@ DROP FUNCTION psql_error;
\dP regression."no.such.schema"."no.such.partitioned.relation"
\dT regression."no.such.schema"."no.such.data.type"
\dX regression."no.such.schema"."no.such.extended.statistics"
+\dV regression."no.such.schema"."no.such.variable"
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -1884,6 +1904,7 @@ DROP FUNCTION psql_error;
\dP "no.such.database"."no.such.schema"."no.such.partitioned.relation"
\dT "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
new file mode 100644
index 00000000000..eeb0f94ca3c
--- /dev/null
+++ b/src/test/regress/sql/session_variables.sql
@@ -0,0 +1,297 @@
+CREATE ROLE regress_variable_owner;
+
+SET log_statement TO ddl;
+
+-- should be ok
+CREATE VARIABLE var1 AS int;
+
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+
+-- should fail
+CREATE VARIABLE var1 AS int;
+
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TABLE t1;
+
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TABLE t1;
+
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TYPE t1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+SET log_statement TO default;
+
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+
+CREATE VARIABLE var1 AS testvar_domain;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+CREATE VARIABLE var1 AS testvar_type;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+
+DROP VARIABLE var1;
+
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+
+DROP SCHEMA vartest1 CASCADE;
+DROP SCHEMA vartest2 CASCADE;
+
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+
+CREATE ROLE regress_variable_reader;
+
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+
+DROP VARIABLE public.varxx;
+
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE public.var1 AS int;
+
+SET search_path TO public;
+
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+
+SET ROLE TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+--
+-- end of function has_session_variable_privilege tests.
+--
+
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+
+DROP VARIABLE public.var1;
+
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+
+DROP ROLE regress_variable_owner;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 449bafc123c..53b414bd982 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -553,6 +553,7 @@ CreateRoleStmt
CreateSchemaStmt
CreateSchemaStmtContext
CreateSeqStmt
+CreateSessionVarStmt
CreateStatsStmt
CreateStmt
CreateStmtContext
@@ -893,6 +894,7 @@ FormData_pg_ts_parser
FormData_pg_ts_template
FormData_pg_type
FormData_pg_user_mapping
+FormData_pg_variable
FormExtraData_pg_attribute
Form_pg_aggregate
Form_pg_am
@@ -952,6 +954,7 @@ Form_pg_ts_parser
Form_pg_ts_template
Form_pg_type
Form_pg_user_mapping
+Form_pg_variable
FormatNode
FreeBlockNumberArray
FreeListData
@@ -3164,6 +3167,7 @@ VarString
VarStringSortSupport
Variable
VariableAssignHook
+VariableInfo
VariableSetKind
VariableSetStmt
VariableShowStmt
--
2.49.0
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-04-05 10:33 ` Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Pavel Stehule @ 2025-04-05 10:33 UTC (permalink / raw)
To: Marcos Pegoraro <[email protected]>; +Cc: jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
Hi
only rebase
Regards
Pavel
Attachments:
[text/x-patch] v20250405-0008-variable-fence-syntax-support-and-variable-fence-usa.patch (19.5K, ../../CAFj8pRAx-Gb9Ux825cxGNm38qQUOrij1GY6erPRaQ=cpqfiX7g@mail.gmail.com/3-v20250405-0008-variable-fence-syntax-support-and-variable-fence-usa.patch)
download | inline diff:
From ce63b7e0c1fc9dd3bf186f9baac59eb9f28ecb60 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 19 Nov 2024 08:14:53 +0100
Subject: [PATCH 08/21] variable fence syntax support and variable fence usage
guard support
this patch introduces a concept of variable fence - syntax for variable
reference `VARIABLE(varname)` that is not in collision with column reference.
When variable fence usage guard warning is active, then usage variable
without variable fence in the case, where there can be column references,
the the warning is raised.
initial implementation of variable fence
---
doc/src/sgml/config.sgml | 65 ++++++++++++++++
doc/src/sgml/ddl.sgml | 15 ++++
src/backend/nodes/nodeFuncs.c | 6 ++
src/backend/parser/gram.y | 28 ++++++-
src/backend/parser/parse_expr.c | 74 ++++++++++++++++++-
src/backend/parser/parse_target.c | 7 ++
src/backend/utils/adt/ruleutils.c | 12 ++-
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/nodes/parsenodes.h | 10 +++
src/include/nodes/primnodes.h | 2 +
src/include/parser/parse_expr.h | 1 +
.../regress/expected/session_variables.out | 59 +++++++++++++++
src/test/regress/sql/session_variables.sql | 41 ++++++++++
14 files changed, 323 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 0069e785c79..ec4a0bc7d05 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11390,6 +11390,71 @@ DETAIL: Session variables can be shadowed by columns, routine's variables and r
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-use-fence-warning-guard" xreflabel="session_variables_use_fence_warning_guard">
+ <term><varname>session_variables_use_fence_warning_guard</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_use_fence_warning_guard</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when a session variable identifier is used
+ inside a query without variable fence. The default is <literal>off</literal>.
+ The warning is raised only when variable is used in places, where an
+ collisions with column names is possible.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE b int;
+LET b = 100;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_use_fence_warning_guard TO on;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "b" is not used inside variable fence
+LINE 1: SELECT a, b FROM foo;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SELECT a, VARIABLE(b) FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+ </para>
+
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. Unless another collision resolution technique is used
+ (dedicated schema or using prefixes like <literal>_</literal>),
+ the use of variable fence syntax is strongly recommended, and this
+ warning should be enabled.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index d73d84d6676..cddecf0301d 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5460,6 +5460,21 @@ SELECT name FROM foo;
<literal>schema.variable</literal>. It is strongly recommended to rename
shadowed variables or use qualified names always.
</para>
+
+ <para><firstterm>Variable fence</firstterm> is special syntax for session
+ variable identifier. Only name or qualified name can be used inside the
+ variable fence, and this name is used as only session variable identifier.
+<programlisting>
+SELECT VARIABLE(current_user_id);
+</programlisting>
+ </para>
+
+ <para>
+ When there is a risk of possible collisions between variable identifiers
+ and column names, then using variable fence syntax can be recommended.
+ Usage session variable without variable fence can be detected by
+ warning <xref linkend="guc-session-variables-use-fence-warning-guard"/>.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d8fc3d9fa69..575365eefcd 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1673,6 +1673,9 @@ exprLocation(const Node *expr)
case T_ParamRef:
loc = ((const ParamRef *) expr)->location;
break;
+ case T_VariableFence:
+ loc = ((const VariableFence *) expr)->location;
+ break;
case T_A_Const:
loc = ((const A_Const *) expr)->location;
break;
@@ -4715,6 +4718,9 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_VariableFence:
+ /* we assume the fields contain nothing interesting */
+ break;
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index f2d3d9ab850..cc15cf2ea43 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -525,7 +525,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <node> def_arg columnElem where_clause where_or_current_clause
a_expr b_expr c_expr AexprConst indirection_el opt_slice_bound
columnref in_expr having_clause func_table xmltable array_expr
- OptWhereClause operator_def_arg
+ OptWhereClause operator_def_arg variable_fence
%type <list> opt_column_and_period_list
%type <list> rowsfrom_item rowsfrom_list opt_col_def_list
%type <boolean> opt_ordinality opt_without_overlaps
@@ -882,7 +882,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
*/
%nonassoc UNBOUNDED NESTED /* ideally would have same precedence as IDENT */
%nonassoc IDENT PARTITION RANGE ROWS GROUPS PRECEDING FOLLOWING CUBE ROLLUP
- SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH
+ SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH VARIABLE
%left Op OPERATOR /* multi-character ops and user-defined operators */
%left '+' '-'
%left '*' '/' '%'
@@ -15692,6 +15692,19 @@ c_expr: columnref { $$ = $1; }
else
$$ = $2;
}
+ | variable_fence opt_indirection
+ {
+ if ($2)
+ {
+ A_Indirection *n = makeNode(A_Indirection);
+
+ n->arg = (Node *) $1;
+ n->indirection = check_indirection($2, yyscanner);
+ $$ = (Node *) n;
+ }
+ else
+ $$ = $1;
+ }
| case_expr
{ $$ = $1; }
| func_expr
@@ -17078,6 +17091,17 @@ case_arg: a_expr { $$ = $1; }
| /*EMPTY*/ { $$ = NULL; }
;
+variable_fence:
+ VARIABLE '(' any_name ')'
+ {
+ VariableFence *vf = makeNode(VariableFence);
+
+ vf->varname = $3;
+ vf->location = @3;
+ $$ = (Node *) vf;
+ }
+ ;
+
columnref: ColId
{
$$ = makeColumnRef($1, NIL, @1, yyscanner);
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index dccc5030438..a439a156216 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -46,6 +46,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
bool session_variables_ambiguity_warning = false;
+bool session_variables_use_fence_warning_guard = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -81,6 +82,7 @@ static Node *transformWholeRowRef(ParseState *pstate,
static Node *transformIndirection(ParseState *pstate, A_Indirection *ind);
static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
static Node *transformCollateClause(ParseState *pstate, CollateClause *c);
+static Node *transformVariableFence(ParseState *pstate, VariableFence *vf);
static Node *transformJsonObjectConstructor(ParseState *pstate,
JsonObjectConstructor *ctor);
static Node *transformJsonArrayConstructor(ParseState *pstate,
@@ -112,7 +114,7 @@ static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
static Node *makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location);
+ char *attrname, bool fenced, int location);
/*
@@ -377,6 +379,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
result = transformJsonFuncExpr(pstate, (JsonFuncExpr *) expr);
break;
+ case T_VariableFence:
+ result = transformVariableFence(pstate, (VariableFence *) expr);
+ break;
+
default:
/* should not reach here */
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
@@ -1028,7 +1034,20 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
node = makeParamSessionVariable(pstate,
varid, typid, typmod, collid,
- attrname, cref->location);
+ attrname, false, cref->location);
+
+ /*
+ * The variable is not inside variable's fence, so raise warning
+ * when variable fence guard is active and the query has FROM
+ * clause.
+ */
+ if (session_variables_use_fence_warning_guard && pstate->p_rtable)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is not used inside variable fence",
+ NameListToString(cref->fields)),
+ errdetail("The collision of session variable' names and column names is possible."),
+ parser_errposition(pstate, cref->location)));
}
}
}
@@ -1071,7 +1090,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
static Node *
makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location)
+ char *attrname, bool fenced, int location)
{
Param *param;
@@ -1079,6 +1098,7 @@ makeParamSessionVariable(ParseState *pstate,
param->paramkind = PARAM_VARIABLE;
param->paramvarid = varid;
+ param->paramvarfenced = fenced;
param->paramtype = typid;
param->paramtypmod = typmod;
param->paramcollid = collid;
@@ -1157,6 +1177,54 @@ transformParamRef(ParseState *pstate, ParamRef *pref)
return result;
}
+static Node *
+transformVariableFence(ParseState *pstate, VariableFence *vf)
+{
+ Node *result;
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* VariableFence can be used only in context when variables are supported */
+ if (!expr_kind_allows_session_variables(pstate->p_expr_kind))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable reference is not supported here"),
+ parser_errposition(pstate, vf->location)));
+
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(vf->varname, &attrname, ¬_unique, false);
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ result = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, true, vf->location);
+ }
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ return result;
+}
+
/* Test whether an a_expr is a plain NULL constant or not */
static bool
exprIsNullConstant(Node *arg)
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d5..cf01bff65a9 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -2034,6 +2034,13 @@ FigureColnameInternal(Node *node, char **name)
(int) ((JsonFuncExpr *) node)->op);
}
break;
+ case T_VariableFence:
+ {
+ /* return last field name */
+ *name = strVal(llast(((VariableFence *) node)->varname));
+ return 2;
+ }
+ break;
default:
break;
}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index d6bdae9af7d..e0e15d1c64c 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8734,8 +8734,16 @@ get_parameter(Param *param, deparse_context *context)
/* translate paramvarid to session variable name */
if (param->paramkind == PARAM_VARIABLE)
{
- appendStringInfo(context->buf, "%s",
- generate_session_variable_name(param->paramvarid));
+ if (param->paramvarfenced)
+ {
+ appendStringInfo(context->buf, "VARIABLE(%s)",
+ generate_session_variable_name(param->paramvarid));
+ }
+ else
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ }
return;
}
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 1ee54cfb69e..94bde564d9b 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1641,6 +1641,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_use_fence_warning_guard", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when variable is not used inside variable fence."),
+ NULL
+ },
+ &session_variables_use_fence_warning_guard,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 5f5296e7b73..9a5df498ebe 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -759,6 +759,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_deferrable = off
#session_replication_role = 'origin'
#session_variables_ambiguity_warning = off
+#session_variables_use_fence_warning_guard = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 321235c6491..f73ec20d665 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -321,6 +321,16 @@ typedef struct ParamRef
ParseLoc location; /* token location, or -1 if unknown */
} ParamRef;
+/*
+ * VariableFence - ensure so fields will be interpretted as a variable
+ */
+typedef struct VariableFence
+{
+ NodeTag type;
+ List *varname; /* variable name (String nodes) */
+ ParseLoc location; /* token location, or -1 if unknown */
+} VariableFence;
+
/*
* A_Expr - infix, prefix, and postfix expressions
*/
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 3cc2f019abb..98bca694480 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -411,6 +411,8 @@ typedef struct Param
* param is used just for execution of UPDATE operation.
*/
bool parambasenode;
+ /* true when variable is used inside an fence */
+ bool paramvarfenced;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index d2209070181..5bde43758d1 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -18,6 +18,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
extern PGDLLIMPORT bool session_variables_ambiguity_warning;
+extern PGDLLIMPORT bool session_variables_use_fence_warning_guard;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7c350ad5ef9..9ac08a14e0b 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1969,3 +1969,62 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
NOTICE: drop cascades to session variable xxtab.avar
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+CREATE SCHEMA testvar;
+SET search_path TO 'testvar';
+CREATE VARIABLE a AS int;
+LET a = 10;
+CREATE TABLE test_table(a int, b int);
+INSERT INTO test_table VALUES(20, 20);
+-- no warning
+SELECT a;
+ a
+----
+ 10
+(1 row)
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a | b
+----+----
+ 20 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a) FROM test_table;
+ a
+----
+ 10
+(1 row)
+
+ALTER TABLE test_table DROP COLUMN a;
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is not used inside variable fence
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+DROP SCHEMA testvar;
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 68be415bf26..c5420183d94 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1360,3 +1360,44 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
+
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+
+CREATE SCHEMA testvar;
+
+SET search_path TO 'testvar';
+
+CREATE VARIABLE a AS int;
+LET a = 10;
+
+CREATE TABLE test_table(a int, b int);
+
+INSERT INTO test_table VALUES(20, 20);
+
+-- no warning
+SELECT a;
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a) FROM test_table;
+
+ALTER TABLE test_table DROP COLUMN a;
+
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+
+DROP SCHEMA testvar;
+
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
--
2.49.0
[text/x-patch] v20250405-0006-plpgsql-tests.patch (16.9K, ../../CAFj8pRAx-Gb9Ux825cxGNm38qQUOrij1GY6erPRaQ=cpqfiX7g@mail.gmail.com/4-v20250405-0006-plpgsql-tests.patch)
download | inline diff:
From fd3451419698cb61a38d712ba4ad33d406c04cfc Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 14:06:06 +0100
Subject: [PATCH 06/21] plpgsql tests
---
src/pl/plpgsql/src/Makefile | 3 +-
.../src/expected/plpgsql_session_variable.out | 382 ++++++++++++++++++
src/pl/plpgsql/src/meson.build | 1 +
.../src/sql/plpgsql_session_variable.sql | 289 +++++++++++++
4 files changed, 674 insertions(+), 1 deletion(-)
create mode 100644 src/pl/plpgsql/src/expected/plpgsql_session_variable.out
create mode 100644 src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile
index 63cb96fae3e..bbcae27d422 100644
--- a/src/pl/plpgsql/src/Makefile
+++ b/src/pl/plpgsql/src/Makefile
@@ -35,7 +35,8 @@ REGRESS_OPTS = --dbname=$(PL_TESTDB)
REGRESS = plpgsql_array plpgsql_cache plpgsql_call plpgsql_control \
plpgsql_copy plpgsql_domain plpgsql_misc \
plpgsql_record plpgsql_simple plpgsql_transaction \
- plpgsql_trap plpgsql_trigger plpgsql_varprops
+ plpgsql_trap plpgsql_trigger plpgsql_varprops \
+ plpgsql_session_variable
# where to find gen_keywordlist.pl and subsidiary files
TOOLSDIR = $(top_srcdir)/src/tools
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
new file mode 100644
index 00000000000..ab779900596
--- /dev/null
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -0,0 +1,382 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+LET plpgsql_sv_var = pi();
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+NOTICE: value of session variable is 3.14159265358979
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+ pi_multiply_2
+------------------
+ 6.28318530717959
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var;
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+END;
+-- execute outside of a transaction
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP FUNCTION test_func();
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+SET ROLE TO regress_var_owner_role;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_reader_role;
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail
+SELECT var_read_func();
+ERROR: permission denied for session variable plpgsql_sv_var1
+CONTEXT: PL/pgSQL expression "plpgsql_sv_var1"
+PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should be ok
+SELECT var_read_func();
+NOTICE: 10
+ var_read_func
+---------------
+
+(1 row)
+
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+DROP VARIABLE plpgsql_sv_var1;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail, but not crash
+SELECT var_read_func();
+ERROR: column "plpgsql_sv_var1" does not exist
+LINE 1: plpgsql_sv_var1
+ ^
+QUERY: plpgsql_sv_var1
+CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+DROP FUNCTION var_read_func;
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+ inc_var_int
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+LET plpgsql_sv_var2 = 0.0;
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+ inc_var_num
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+NOTICE: variable is 1000
+DROP VARIABLE plpgsql_sv_var1;
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+select ffunc();
+ ffunc
+-------
+ abc
+(1 row)
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+DROP VARIABLE plpgsql_sv_v;
diff --git a/src/pl/plpgsql/src/meson.build b/src/pl/plpgsql/src/meson.build
index 33c49ac25d9..1d01d1c2629 100644
--- a/src/pl/plpgsql/src/meson.build
+++ b/src/pl/plpgsql/src/meson.build
@@ -88,6 +88,7 @@ tests += {
'plpgsql_trap',
'plpgsql_trigger',
'plpgsql_varprops',
+ 'plpgsql_session_variable',
],
},
}
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
new file mode 100644
index 00000000000..a3cc264cf38
--- /dev/null
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -0,0 +1,289 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+
+LET plpgsql_sv_var = pi();
+
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+
+DROP VARIABLE plpgsql_sv_var;
+
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+END;
+
+-- execute outside of a transaction
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+SELECT test_func();
+
+DROP FUNCTION test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+SET ROLE TO regress_var_owner_role;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_reader_role;
+
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should be ok
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail, but not crash
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+DROP FUNCTION var_read_func;
+
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+
+LET plpgsql_sv_var2 = 0.0;
+
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+
+select ffunc();
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+
+DROP VARIABLE plpgsql_sv_v;
--
2.49.0
[text/x-patch] v20250405-0007-GUC-session_variables_ambiguity_warning.patch (15.1K, ../../CAFj8pRAx-Gb9Ux825cxGNm38qQUOrij1GY6erPRaQ=cpqfiX7g@mail.gmail.com/5-v20250405-0007-GUC-session_variables_ambiguity_warning.patch)
download | inline diff:
From 66ec8339ddb26f2bc86ac1ac7ef18458fb226943 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 21 May 2024 17:55:24 +0200
Subject: [PATCH 07/21] GUC session_variables_ambiguity_warning
Inside an query the session variables can be shadowed. This behaviour is by design,
because this ensuring so new variables doesn't break existing queries. But this
behaviour can be confusing, because shadowing is quiet.
When new GUC session_variables_ambiguity_warning is on, then the warning
is displayed, when some session variable can be used, but it is not used
due shadowing. This feature should to help with investigation of unexpected
behaviour.
Note: PLpgSQL has an option that controls priority of identifier's spaces
(SQL or PLpgSQL). Default behaviour doesn't allows collisions. I believe
this default is the best. I cannot to implement similar very strict
behaviour to session variables, because one unhappy named session variable
can breaks an applications. The problems related to badly named PLpgSQL's
varible is limitted just to only one routine.
---
doc/src/sgml/config.sgml | 60 +++++++++++++++++++
doc/src/sgml/ddl.sgml | 11 ++++
src/backend/parser/parse_expr.c | 49 +++++++++++++--
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/parser/parse_expr.h | 1 +
.../src/expected/plpgsql_session_variable.out | 33 ++++++++++
.../src/sql/plpgsql_session_variable.sql | 29 +++++++++
.../regress/expected/session_variables.out | 26 ++++++++
src/test/regress/sql/session_variables.sql | 26 ++++++++
10 files changed, 241 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index fea683cb49c..0069e785c79 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11330,6 +11330,66 @@ dynamic_library_path = '/usr/local/lib/postgresql:$libdir'
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-ambiguity-warning" xreflabel="session_variables_ambiguity_warning">
+ <term><varname>session_variables_ambiguity_warning</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_ambiguity_warning</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when any identifier in a query could be
+ used as both a column identifier, routine variable or a session
+ variable identifier. The default is <literal>off</literal>.
+ </para>
+ <para>
+ Session variables can be shadowed by column references in a query, this
+ is an expected behavior. Previously working queries shouldn't error out
+ by creating any session variable, so session variables are always shadowed
+ if an identifier is ambiguous. Variables should be referenced using
+ anunambiguous identifier without any possibility for a collision with
+ identifier of other database objects (column names or record fields names).
+ The warning messages emitted when enabling <varname>session_variables_ambiguity_warning</varname>
+ can help finding such identifier collision.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE a int;
+LET a = 100;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+ a
+----
+ 10
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_ambiguity_warning TO on;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a FROM foo;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a
+----
+ 10
+(1 row)
+</screen>
+ </para>
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. For testing or development environments it's recommended to
+ enable it if you use session variables.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index fce5e72bbf6..d73d84d6676 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5449,6 +5449,17 @@ SELECT name FROM foo;
Alice
</programlisting>
</para>
+
+ <para>
+ When a query contains identifiers or qualified identifiers that could be
+ used as both a session variable identifiers and as column identifier,
+ then the column identifier is preferred every time. Warnings can be
+ emitted when this situation happens by enabling configuration parameter <xref
+ linkend="guc-session-variables-ambiguity-warning"/>. User can explicitly
+ qualify the source object by syntax <literal>table.column</literal> or
+ <literal>schema.variable</literal>. It is strongly recommended to rename
+ shadowed variables or use qualified names always.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 55e4906ad76..dccc5030438 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -45,6 +45,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
+bool session_variables_ambiguity_warning = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -960,11 +961,51 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
*
* SELECT foo.a, foo.b, foo.c FROM foo;
*
- * However, that is very confusing, so we disallow it. We don't try to
- * identify a variable if we know that it would be shadowed.
- * -----
+ * However, that is very confusing, so we disallow it.
+ *
+ * When session_variables_ambiguity_warning is requested, then we
+ * need to identify a variable although we know, so this variable
+ * would be shadowed.
*/
- if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ if (node || (relname && crerr == CRERR_NO_COLUMN))
+ {
+ /*
+ * In this path we just try (if it is wanted) detect if session
+ * variable is shadowed.
+ */
+ if (session_variables_ambiguity_warning)
+ {
+ /*
+ * The AccessShareLock is created on related session variable.
+ * The lock will be kept for the whole transaction.
+ */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, true);
+
+ if (OidIsValid(varid))
+ {
+ /* this path will ending by WARNING. Unlock variable first */
+ UnlockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (node)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is shadowed",
+ NameListToString(cref->fields)),
+ errdetail("Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name."),
+ parser_errposition(pstate, cref->location)));
+ else
+ /* session variable is shadowed by RTE */
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s.%s\" is shadowed",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ errdetail("Session variables can be shadowed by tables or table's aliases with the same name."),
+ parser_errposition(pstate, cref->location)));
+ }
+ }
+ }
+ else
{
/* takes an AccessShareLock on the session variable */
varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 4eaeca89f2c..1ee54cfb69e 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1632,6 +1632,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_ambiguity_warning", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when reference to a session variable is ambiguous."),
+ NULL
+ },
+ &session_variables_ambiguity_warning,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index ff56a1f0732..5f5296e7b73 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -758,6 +758,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_read_only = off
#default_transaction_deferrable = off
#session_replication_role = 'origin'
+#session_variables_ambiguity_warning = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index efbaff8e710..d2209070181 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -17,6 +17,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
+extern PGDLLIMPORT bool session_variables_ambiguity_warning;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index ab779900596..a6523f7afe2 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -354,6 +354,39 @@ $$;
NOTICE: session variable is 100
NOTICE: plpgsql variable is 1000
NOTICE: variable is 1000
+-- againt with session_variables_ambiguity_warning(on)
+SET session_variables_ambiguity_warning TO on;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+WARNING: session variable "plpgsql_sv_var1" is shadowed
+LINE 1: plpgsql_sv_var1
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+QUERY: plpgsql_sv_var1
+NOTICE: variable is 1000
+SET session_variables_ambiguity_warning TO off;
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
CREATE VARIABLE plpgsql_sv_v text;
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
index a3cc264cf38..9b8e90e81fa 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -260,6 +260,35 @@ BEGIN
END;
$$;
+-- againt with session_variables_ambiguity_warning(on)
+
+SET session_variables_ambiguity_warning TO on;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+SET session_variables_ambiguity_warning TO off;
+
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 2783caa8446..7c350ad5ef9 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1524,6 +1524,9 @@ CREATE TABLE vartest_foo(a int, b int);
INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
-- should to fail
SELECT var1.* FROM vartest_foo;
ERROR: missing FROM-clause entry for table "var1"
@@ -1549,6 +1552,7 @@ SELECT count(var1.*) FROM vartest_foo var1;
2
(1 row)
+SET session_variables_ambiguity_warning TO off;
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
NOTICE: drop cascades to 2 other objects
@@ -1943,3 +1947,25 @@ SELECT var1;
(1 row)
DROP VARIABLE var1, var2;
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+CREATE VARIABLE xxtab.avar int;
+CREATE TABLE public.xxtab(avar int);
+INSERT INTO public.xxtab VALUES(1);
+LET xxtab.avar = 20;
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+WARNING: session variable "xxtab.avar" is shadowed
+LINE 1: SELECT xxtab.avar FROM public.xxtab;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ avar
+------
+ 1
+(1 row)
+
+SET session_variables_ambiguity_warning TO off;
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
+NOTICE: drop cascades to session variable xxtab.avar
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index a624ab8b67f..68be415bf26 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1079,6 +1079,10 @@ INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
+
-- should to fail
SELECT var1.* FROM vartest_foo;
@@ -1091,6 +1095,8 @@ SELECT count(var1.*) FROM vartest_foo;
-- should be ok
SELECT count(var1.*) FROM vartest_foo var1;
+SET session_variables_ambiguity_warning TO off;
+
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
@@ -1334,3 +1340,23 @@ BEGIN; DROP VARIABLE var1; ROLLBACK;
SELECT var1;
DROP VARIABLE var1, var2;
+
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+
+CREATE VARIABLE xxtab.avar int;
+
+CREATE TABLE public.xxtab(avar int);
+
+INSERT INTO public.xxtab VALUES(1);
+
+LET xxtab.avar = 20;
+
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+
+SET session_variables_ambiguity_warning TO off;
+
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
--
2.49.0
[text/x-patch] v20250405-0005-memory-cleaning-after-DROP-VARIABLE.patch (20.9K, ../../CAFj8pRAx-Gb9Ux825cxGNm38qQUOrij1GY6erPRaQ=cpqfiX7g@mail.gmail.com/6-v20250405-0005-memory-cleaning-after-DROP-VARIABLE.patch)
download | inline diff:
From f6619c803ef494aef764cf499c84cba4550a27d3 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 09:31:28 +0100
Subject: [PATCH 05/21] memory cleaning after DROP VARIABLE
Accepting a sinval message invalidates entries in the "sessionvars" hash table.
These entries are validated before any read or write operations on session variables.
When the entry cannot be validated, it is removed. Removal will be delayed when
the variable was dropped by the current transaction, which could still be rolled back.
---
src/backend/catalog/pg_variable.c | 7 +-
src/backend/commands/session_variable.c | 153 +++++++++++-
src/include/commands/session_variable.h | 2 +
.../isolation/expected/session-variable.out | 110 +++++++++
src/test/isolation/isolation_schedule | 1 +
.../isolation/specs/session-variable.spec | 50 ++++
.../regress/expected/session_variables.out | 217 ++++++++++++++++++
src/test/regress/sql/session_variables.sql | 120 ++++++++++
8 files changed, 655 insertions(+), 5 deletions(-)
create mode 100644 src/test/isolation/expected/session-variable.out
create mode 100644 src/test/isolation/specs/session-variable.spec
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index bb445e9434b..d672d2a9cb3 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -22,6 +22,7 @@
#include "catalog/pg_collation.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
@@ -230,7 +231,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
}
/*
- * Drop variable by OID
+ * Drop variable by OID, and register the needed session variable
+ * cleanup.
*/
void
DropVariableById(Oid varid)
@@ -250,4 +252,7 @@ DropVariableById(Oid varid)
ReleaseSysCache(tup);
table_close(rel, RowExclusiveLock);
+
+ /* do the necessary cleanup in local memory, if needed */
+ SessionVariableDropPostprocess(varid);
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index e1c86966998..1596d94fb03 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -14,6 +14,7 @@
*/
#include "postgres.h"
+#include "access/xact.h"
#include "catalog/pg_variable.h"
#include "commands/session_variable.h"
#include "executor/svariableReceiver.h"
@@ -67,6 +68,14 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ /*
+ * Top level local transaction id of the last transaction that dropped the
+ * variable, if any. We need this information to avoid freeing memory for
+ * variables dropped by the local backend, in case the operation is rolled
+ * back.
+ */
+ LocalTransactionId drop_lxid;
+
/*
* Stored value and type description can be outdated when we receive a
* sinval message. We then have to check if the stored data are still
@@ -83,6 +92,17 @@ static HTAB *sessionvars = NULL; /* hash table for session variables */
static MemoryContext SVariableMemoryContext = NULL;
+/* becomes true when we receive a sinval message */
+static bool needs_validation = false;
+
+/*
+ * The content of dropped session variables is not removed immediately. We do
+ * that in the next transaction that reads or writes a session variable.
+ * "validated_lxid" stores the transaction that performed said validation, so
+ * that we can avoid repeating the effort.
+ */
+static LocalTransactionId validated_lxid = InvalidLocalTransactionId;
+
/*
* Callback function for session variable invalidation.
*/
@@ -114,6 +134,38 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
if (hashvalue == 0 || svar->hashvalue == hashvalue)
{
svar->is_valid = false;
+ needs_validation = true;
+ }
+ }
+}
+
+/*
+ * Handle the local memory cleanup for a DROP VARIABLE command.
+ *
+ * Caller should take care of removing the pg_variable entry first.
+ */
+void
+SessionVariableDropPostprocess(Oid varid)
+{
+ Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid));
+
+ if (sessionvars)
+ {
+ bool found;
+ SVariable svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_FIND, &found);
+
+ if (found)
+ {
+ /*
+ * Save the current top level local transaction id to make sure we
+ * won't automatically remove the local variable storage in
+ * validate_all_session_variables() when the invalidation message
+ * from DROP VARIABLE arrives. After all, the transaction could
+ * still be rolled back.
+ */
+ svar->is_valid = false;
+ svar->drop_lxid = MyProc->vxid.lxid;
}
}
}
@@ -167,6 +219,67 @@ is_session_variable_valid(SVariable svar)
return result;
}
+/*
+ * Check all potentially invalid session variable data in local memory and free
+ * the memory for all invalid ones. This function is called before any read or
+ * write of a session variable. Freeing of a variable's memory is postponed if
+ * the variable has been dropped by the current transaction, since that
+ * operation could still be rolled back.
+ *
+ * It is possible that we receive a cache invalidation message while
+ * remove_invalid_session_variables() is executing, so we cannot guarantee that
+ * all entries in "sessionvars" will be set to "is_valid" after the function is
+ * done. However, we can guarantee that all entries get checked once.
+ */
+static void
+remove_invalid_session_variables(void)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ /*
+ * The validation requires system catalog access, so the session state
+ * should be "in transaction".
+ */
+ Assert(IsTransactionState());
+
+ if (!needs_validation || !sessionvars)
+ return;
+
+ /*
+ * Reset the flag before we start the validation. It can be set again
+ * by concurrently incoming sinval messages.
+ */
+ needs_validation = false;
+
+ elog(DEBUG1, "effective call of validate_all_session_variables()");
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (!svar->is_valid)
+ {
+ if (svar->drop_lxid == MyProc->vxid.lxid)
+ {
+ /* try again in the next transaction */
+ needs_validation = true;
+ continue;
+ }
+
+ if (!is_session_variable_valid(svar))
+ {
+ Oid varid = svar->varid;
+
+ free_session_variable_value(svar);
+ hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ else
+ svar->is_valid = true;
+ }
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
@@ -196,6 +309,8 @@ setup_session_variable(SVariable svar, Oid varid)
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+ svar->drop_lxid = InvalidTransactionId;
+
svar->isnull = true;
svar->value = (Datum) 0;
@@ -319,22 +434,42 @@ get_session_variable(Oid varid)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
if (found)
{
+ /*
+ * The session variable could have been dropped by a DROP VARIABLE
+ * statement in a subtransaction that was later rolled back, which
+ * means that we may have to work with the data of a variable marked
+ * as invalid.
+ */
if (!svar->is_valid)
{
/*
- * If there was an invalidation message, the variable might still be
- * valid, but we have to check with the system catalog.
+ * We have to check the system catalog to see if the variable is
+ * still valid, even if an invalidation message set it to invalid.
+ *
+ * The variable must be validated before it is accessed. The oid
+ * should be valid, because the related session variable is already
+ * locked, and remove_invalid_session_variables() would remove
+ * variables dropped by other transactions.
*/
if (is_session_variable_valid(svar))
svar->is_valid = true;
else
- /* if the value cannot be validated, we have to discard it */
- free_session_variable_value(svar);
+ elog(ERROR, "unexpected state of session variable %u", varid);
}
}
else
@@ -395,6 +530,16 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index a8ca43c87af..d3cc79b5608 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -21,6 +21,8 @@
#include "tcop/cmdtag.h"
#include "utils/queryenvironment.h"
+extern void SessionVariableDropPostprocess(Oid varid);
+
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
new file mode 100644
index 00000000000..0a5579dc7ce
--- /dev/null
+++ b/src/test/isolation/expected/session-variable.out
@@ -0,0 +1,110 @@
+Parsed test spec with 4 sessions
+
+starting permutation: let val drop val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+
+starting permutation: let val s1 drop val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+step sr1: ROLLBACK;
+
+starting permutation: let val dbg drop create dbg val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name|removed
+------+----+-------
+ | |t
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+
+starting permutation: let val s1 dbg drop create dbg val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+step sr1: ROLLBACK;
+
+starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+step create3: CREATE VARIABLE myvar3 AS text;
+step let3: LET myvar3 = 'test';
+step s3: BEGIN;
+step create4: CREATE VARIABLE myvar4 AS text;
+step let4: LET myvar4 = 'test';
+step drop4: DROP VARIABLE myvar4;
+step drop3: DROP VARIABLE myvar3;
+step inval3: SELECT COUNT(*) >= 0 FROM pg_foreign_table;
+?column?
+--------
+t
+(1 row)
+
+step discard: DISCARD VARIABLES;
+step sc3: COMMIT;
+step state: SELECT varname FROM pg_variable;
+varname
+-------
+myvar
+(1 row)
+
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index e3c669a29c7..8df901fc79c 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -116,3 +116,4 @@ test: serializable-parallel-2
test: serializable-parallel-3
test: matview-write-skew
test: lock-nowait
+test: session-variable
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
new file mode 100644
index 00000000000..c864fee4006
--- /dev/null
+++ b/src/test/isolation/specs/session-variable.spec
@@ -0,0 +1,50 @@
+# Test session variables memory cleanup for sinval
+
+setup
+{
+ CREATE VARIABLE myvar AS text;
+}
+
+teardown
+{
+ DROP VARIABLE IF EXISTS myvar;
+}
+
+session s1
+step s1 { BEGIN; }
+step let { LET myvar = 'test'; }
+step val { SELECT myvar; }
+step dbg { SELECT schema, name, removed FROM pg_session_variables(); }
+step sr1 { ROLLBACK; }
+
+session s2
+step drop { DROP VARIABLE myvar; }
+step create { CREATE VARIABLE myvar AS text; }
+
+session s3
+step s3 { BEGIN; }
+step let3 { LET myvar3 = 'test'; }
+step create4 { CREATE VARIABLE myvar4 AS text; }
+step let4 { LET myvar4 = 'test'; }
+step drop4 { DROP VARIABLE myvar4; }
+step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; }
+step discard { DISCARD VARIABLES; }
+step sc3 { COMMIT; }
+step state { SELECT varname FROM pg_variable; }
+
+session s4
+step create3 { CREATE VARIABLE myvar3 AS text; }
+step drop3 { DROP VARIABLE myvar3; }
+
+# Concurrent drop of a known variable should lead to an error
+permutation let val drop val
+# Same, but with an explicit transaction
+permutation let val s1 drop val sr1
+# Concurrent drop/create of a known variable should lead to empty variable
+permutation let val dbg drop create dbg val
+# Concurrent drop/create of a known variable should lead to empty variable
+# We need a transaction to make sure that we won't accept invalidation when
+# calling the dbg step after the concurrent drop
+permutation let val s1 dbg drop create dbg val sr1
+# test for DISCARD ALL when all internal queues have actions registered
+permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 79ac40768f8..2783caa8446 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1726,3 +1726,220 @@ SELECT count(*) FROM pg_session_variables();
0
(1 row)
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+-- should fail
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1, var2;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 2954759aaed..a624ab8b67f 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1214,3 +1214,123 @@ DISCARD VARIABLES;
-- should be zero again
SELECT count(*) FROM pg_session_variables();
+
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+
+-- should fail
+SELECT var1;
+
+ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ROLLBACK;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+DROP VARIABLE var1, var2;
--
2.49.0
[text/x-patch] v20250405-0004-DISCARD-VARIABLES.patch (9.6K, ../../CAFj8pRAx-Gb9Ux825cxGNm38qQUOrij1GY6erPRaQ=cpqfiX7g@mail.gmail.com/7-v20250405-0004-DISCARD-VARIABLES.patch)
download | inline diff:
From 6982e0bb0d857055acf5bcb42b2e603b0a203338 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sun, 28 Jan 2024 20:54:20 +0100
Subject: [PATCH 04/21] DISCARD VARIABLES
Implementation of DISCARD VARIABLES commands by removing hash table with session variables
and resetting related memory context.
---
doc/src/sgml/ref/discard.sgml | 13 +++-
src/backend/commands/discard.c | 6 ++
src/backend/commands/session_variable.c | 28 ++++++++-
src/backend/parser/gram.y | 6 ++
src/backend/tcop/utility.c | 3 +
src/bin/psql/tab-complete.in.c | 2 +-
src/include/commands/session_variable.h | 2 +
src/include/nodes/parsenodes.h | 1 +
src/include/tcop/cmdtaglist.h | 1 +
.../regress/expected/session_variables.out | 63 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 36 +++++++++++
11 files changed, 158 insertions(+), 3 deletions(-)
diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
index bf44c523cac..61b967f9c9b 100644
--- a/doc/src/sgml/ref/discard.sgml
+++ b/doc/src/sgml/ref/discard.sgml
@@ -21,7 +21,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
+DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES }
</synopsis>
</refsynopsisdiv>
@@ -66,6 +66,16 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>VARIABLES</literal></term>
+ <listitem>
+ <para>
+ Resets the value of all session variables. If a variable
+ is later reused, it is re-initialized to <literal>NULL</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><literal>TEMPORARY</literal> or <literal>TEMP</literal></term>
<listitem>
@@ -93,6 +103,7 @@ SELECT pg_advisory_unlock_all();
DISCARD PLANS;
DISCARD TEMP;
DISCARD SEQUENCES;
+DISCARD VARIABLES;
</programlisting></para>
</listitem>
</varlistentry>
diff --git a/src/backend/commands/discard.c b/src/backend/commands/discard.c
index 81339a75a52..5904a6c4917 100644
--- a/src/backend/commands/discard.c
+++ b/src/backend/commands/discard.c
@@ -18,6 +18,7 @@
#include "commands/async.h"
#include "commands/discard.h"
#include "commands/prepare.h"
+#include "commands/session_variable.h"
#include "commands/sequence.h"
#include "utils/guc.h"
#include "utils/portal.h"
@@ -48,6 +49,10 @@ DiscardCommand(DiscardStmt *stmt, bool isTopLevel)
ResetTempTableNamespace();
break;
+ case DISCARD_VARIABLES:
+ ResetSessionVariables();
+ break;
+
default:
elog(ERROR, "unrecognized DISCARD target: %d", stmt->target);
}
@@ -75,4 +80,5 @@ DiscardAll(bool isTopLevel)
ResetPlanCache();
ResetTempTableNamespace();
ResetSequenceCaches();
+ ResetSessionVariables();
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index fa16f47072e..e1c86966998 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -94,7 +94,13 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
- Assert(sessionvars);
+ /*
+ * There is no guarantee of session variables being initialized, even when
+ * receiving an invalidation callback, as DISCARD [ ALL | VARIABLES ]
+ * destroys the hash table entirely.
+ */
+ if (!sessionvars)
+ return;
/*
* If the hashvalue is not specified, we have to recheck all currently
@@ -619,3 +625,23 @@ pg_session_variables(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+
+/*
+ * Fast drop of the complete content of the session variables hash table, and
+ * cleanup of any list that wouldn't be relevant anymore.
+ * This is used by the DISCARD VARIABLES (and DISCARD ALL) command.
+ */
+void
+ResetSessionVariables(void)
+{
+ /* destroy hash table and reset related memory context */
+ if (sessionvars)
+ {
+ hash_destroy(sessionvars);
+ sessionvars = NULL;
+ }
+
+ /* release memory allocated by session variables */
+ if (SVariableMemoryContext != NULL)
+ MemoryContextReset(SVariableMemoryContext);
+}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 9d10f812120..f2d3d9ab850 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -2084,7 +2084,13 @@ DiscardStmt:
n->target = DISCARD_SEQUENCES;
$$ = (Node *) n;
}
+ | DISCARD VARIABLES
+ {
+ DiscardStmt *n = makeNode(DiscardStmt);
+ n->target = DISCARD_VARIABLES;
+ $$ = (Node *) n;
+ }
;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 7a508a3644f..6e4d2310f5c 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -2962,6 +2962,9 @@ CreateCommandTag(Node *parsetree)
case DISCARD_SEQUENCES:
tag = CMDTAG_DISCARD_SEQUENCES;
break;
+ case DISCARD_VARIABLES:
+ tag = CMDTAG_DISCARD_VARIABLES;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 78b130c04b0..9a6d3248f1c 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4146,7 +4146,7 @@ match_previous_words(int pattern_id,
/* DISCARD */
else if (Matches("DISCARD"))
- COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP");
+ COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP", "VARIABLES");
/* DO */
else if (Matches("DO"))
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index 2391b9ad443..a8ca43c87af 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -27,4 +27,6 @@ extern Datum GetSessionVariable(Oid varid, bool *isNull);
extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
QueryEnvironment *queryEnv, QueryCompletion *qc);
+extern void ResetSessionVariables(void);
+
#endif
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 8f874a08d29..321235c6491 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -4056,6 +4056,7 @@ typedef enum DiscardMode
DISCARD_PLANS,
DISCARD_SEQUENCES,
DISCARD_TEMP,
+ DISCARD_VARIABLES,
} DiscardMode;
typedef struct DiscardStmt
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index 22082c30008..bef0ac25331 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -135,6 +135,7 @@ PG_CMDTAG(CMDTAG_DISCARD_ALL, "DISCARD ALL", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_PLANS, "DISCARD PLANS", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_SEQUENCES, "DISCARD SEQUENCES", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_TEMP, "DISCARD TEMP", false, false, false)
+PG_CMDTAG(CMDTAG_DISCARD_VARIABLES, "DISCARD VARIABLES", false, false, false)
PG_CMDTAG(CMDTAG_DO, "DO", false, false, false)
PG_CMDTAG(CMDTAG_DROP_ACCESS_METHOD, "DROP ACCESS METHOD", true, false, false)
PG_CMDTAG(CMDTAG_DROP_AGGREGATE, "DROP AGGREGATE", true, false, false)
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index f22467186e3..79ac40768f8 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1663,3 +1663,66 @@ DROP VARIABLE :"DBNAME".:"DBNAME".b;
DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+ var1
+-------
+ Hello
+(1 row)
+
+DISCARD ALL;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT var1;
+ var1
+------
+ AHOJ
+(1 row)
+
+DISCARD VARIABLES;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+DROP VARIABLE var1;
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS varchar;
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DISCARD VARIABLES;
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index e72360d5254..2954759aaed 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1178,3 +1178,39 @@ DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+
+DISCARD ALL;
+SELECT var1;
+
+LET var1 = 'AHOJ';
+SELECT var1;
+
+DISCARD VARIABLES;
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+
+SELECT count(*) FROM pg_session_variables();
+
+CREATE VARIABLE var1 AS varchar;
+
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+
+LET var1 = 'AHOJ';
+
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+
+DISCARD VARIABLES;
+
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
--
2.49.0
[text/x-patch] v20250405-0003-function-pg_session_variables-for-cleaning-tests.patch (4.4K, ../../CAFj8pRAx-Gb9Ux825cxGNm38qQUOrij1GY6erPRaQ=cpqfiX7g@mail.gmail.com/8-v20250405-0003-function-pg_session_variables-for-cleaning-tests.patch)
download | inline diff:
From 39c44fa3d50d1b2f635e2de92d74170b4232da9a Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 20:01:56 +0100
Subject: [PATCH 03/21] function pg_session_variables for cleaning tests
This is a function designed for testing and debugging. It returns the
content of sessionvars as-is, and can therefore display entries about
session variables that were dropped but for which this backend didn't
process the shared invalidations yet.
---
src/backend/commands/session_variable.c | 92 +++++++++++++++++++++++++
src/include/catalog/pg_proc.dat | 8 +++
2 files changed, 100 insertions(+)
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index d2891a1dcb7..fa16f47072e 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -527,3 +527,95 @@ ExecuteLetStmt(ParseState *pstate,
PopActiveSnapshot();
}
+
+/*
+ * pg_session_variables - designed for testing
+ *
+ * This is a function designed for testing and debugging. It returns the
+ * content of session variables as-is, and can therefore display data about
+ * session variables that were dropped, but for which this backend didn't
+ * process the shared invalidations yet.
+ */
+Datum
+pg_session_variables(PG_FUNCTION_ARGS)
+{
+#define NUM_PG_SESSION_VARIABLES_ATTS 8
+
+ InitMaterializedSRF(fcinfo, 0);
+
+ if (sessionvars)
+ {
+ ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ Datum values[NUM_PG_SESSION_VARIABLES_ATTS];
+ bool nulls[NUM_PG_SESSION_VARIABLES_ATTS];
+ HeapTuple tp;
+ bool var_is_valid = false;
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, 0, sizeof(nulls));
+
+ values[0] = ObjectIdGetDatum(svar->varid);
+ values[3] = ObjectIdGetDatum(svar->typid);
+
+ /*
+ * It is possible that the variable has been dropped from the
+ * catalog, but not yet purged from the hash table.
+ */
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ Form_pg_variable varform = (Form_pg_variable) GETSTRUCT(tp);
+
+ /*
+ * It is also possible that a variable has been dropped and
+ * someone created a new variable with the same object ID. Use
+ * the catalog information only if that is not the case.
+ */
+ if (svar->create_lsn == varform->varcreate_lsn)
+ {
+ values[1] = CStringGetTextDatum(
+ get_namespace_name(varform->varnamespace));
+
+ values[2] = CStringGetTextDatum(NameStr(varform->varname));
+ values[4] = CStringGetTextDatum(format_type_be(svar->typid));
+ values[5] = BoolGetDatum(false);
+
+ values[6] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_SELECT) == ACLCHECK_OK);
+
+ values[7] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_UPDATE) == ACLCHECK_OK);
+
+ var_is_valid = true;
+ }
+
+ ReleaseSysCache(tp);
+ }
+
+ /* if there is no matching catalog entry, return null values */
+ if (!var_is_valid)
+ {
+ nulls[1] = true;
+ nulls[2] = true;
+ nulls[4] = true;
+ values[5] = BoolGetDatum(true);
+ nulls[6] = true;
+ nulls[7] = true;
+ }
+
+ tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
+ }
+ }
+
+ return (Datum) 0;
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index e27a127ba59..06ed5a3de63 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -12567,4 +12567,12 @@
proargnames => '{pid,io_id,io_generation,state,operation,off,length,target,handle_data_len,raw_result,result,target_desc,f_sync,f_localmem,f_buffered}',
prosrc => 'pg_get_aios' },
+# Session variables support
+{ oid => '8488', descr => 'list of used session variables',
+ proname => 'pg_session_variables', prorows => '1000', proretset => 't',
+ provolatile => 's', proparallel => 'r', prorettype => 'record',
+ proargtypes => '', proallargtypes => '{oid,text,text,oid,text,bool,bool,bool}',
+ proargmodes => '{o,o,o,o,o,o,o,o}',
+ proargnames => '{varid,schema,name,typid,typname,removed,can_select,can_update}',
+ prosrc => 'pg_session_variables' },
]
--
2.49.0
[text/x-patch] v20250405-0002-Storage-for-session-variables-and-SQL-interface.patch (159.6K, ../../CAFj8pRAx-Gb9Ux825cxGNm38qQUOrij1GY6erPRaQ=cpqfiX7g@mail.gmail.com/9-v20250405-0002-Storage-for-session-variables-and-SQL-interface.patch)
download | inline diff:
From b1ac3cd50ff6a8b565cfa6dd0b72a5c0ee2396fe Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Thu, 6 Jul 2023 08:29:21 +0200
Subject: [PATCH 02/21] Storage for session variables and SQL interface
Session variables are stored in session memory in a dedicated hash table.
They are set by the LET command and read by the SELECT command.
The access rights should be checked.
The identifiers of session variables should always be shadowed by possible
column identifiers: we don't want to break an application by creating some
badly named session variable.
The limits of this patch (solved by other patches):
- session variables block parallel execution
- session variables blocks simple expression evaluation (in plpgsql)
- SQL functions with session variables are not inlined
- CALL statement is not supported (usage of direct access to express executor)
- EXECUTE statement is not supported (usage of direct access to express executor)
- memory used by dropped session variables is not released
Implementations of EXPLAIN LET and PREPARE LET statements
are in separate patches (for better readability)
---
doc/src/sgml/catalogs.sgml | 13 +
doc/src/sgml/ddl.sgml | 61 +
doc/src/sgml/func.sgml | 4 +-
doc/src/sgml/glossary.sgml | 5 +-
doc/src/sgml/parallel.sgml | 6 +
doc/src/sgml/plpgsql.sgml | 14 +
doc/src/sgml/ref/allfiles.sgml | 1 +
doc/src/sgml/ref/alter_variable.sgml | 1 +
doc/src/sgml/ref/create_variable.sgml | 5 +-
doc/src/sgml/ref/drop_variable.sgml | 1 +
doc/src/sgml/ref/let.sgml | 96 ++
doc/src/sgml/reference.sgml | 1 +
src/backend/catalog/dependency.c | 5 +
src/backend/catalog/namespace.c | 289 ++++
src/backend/catalog/pg_variable.c | 2 +
src/backend/commands/Makefile | 1 +
src/backend/commands/meson.build | 1 +
src/backend/commands/prepare.c | 10 +
src/backend/commands/session_variable.c | 529 +++++++
src/backend/executor/Makefile | 1 +
src/backend/executor/execExpr.c | 32 +
src/backend/executor/execMain.c | 66 +
src/backend/executor/meson.build | 1 +
src/backend/executor/svariableReceiver.c | 172 +++
src/backend/nodes/nodeFuncs.c | 10 +
src/backend/optimizer/plan/planner.c | 36 +
src/backend/optimizer/plan/setrefs.c | 156 ++-
src/backend/optimizer/prep/prepjointree.c | 3 +
src/backend/optimizer/util/clauses.c | 33 +-
src/backend/parser/analyze.c | 272 +++-
src/backend/parser/gram.y | 39 +-
src/backend/parser/parse_agg.c | 9 +
src/backend/parser/parse_expr.c | 223 ++-
src/backend/parser/parse_func.c | 2 +
src/backend/parser/parse_merge.c | 1 +
src/backend/tcop/dest.c | 7 +
src/backend/tcop/utility.c | 16 +
src/backend/utils/adt/ruleutils.c | 46 +
src/backend/utils/cache/plancache.c | 41 +-
src/backend/utils/fmgr/fmgr.c | 10 +-
src/bin/psql/tab-complete.in.c | 12 +-
src/include/catalog/namespace.h | 1 +
src/include/catalog/pg_variable.h | 9 +
src/include/commands/session_variable.h | 30 +
src/include/executor/svariableReceiver.h | 22 +
src/include/nodes/execnodes.h | 14 +
src/include/nodes/parsenodes.h | 17 +
src/include/nodes/pathnodes.h | 14 +
src/include/nodes/plannodes.h | 9 +
src/include/nodes/primnodes.h | 14 +
src/include/optimizer/planmain.h | 2 +
src/include/parser/kwlist.h | 1 +
src/include/parser/parse_node.h | 3 +
src/include/tcop/cmdtaglist.h | 1 +
src/include/tcop/dest.h | 1 +
src/pl/plpgsql/src/pl_exec.c | 3 +-
.../regress/expected/session_variables.out | 1232 +++++++++++++++++
src/test/regress/sql/session_variables.sql | 883 ++++++++++++
src/tools/pgindent/typedefs.list | 5 +
59 files changed, 4467 insertions(+), 27 deletions(-)
create mode 100644 doc/src/sgml/ref/let.sgml
create mode 100644 src/backend/commands/session_variable.c
create mode 100644 src/backend/executor/svariableReceiver.c
create mode 100644 src/include/commands/session_variable.h
create mode 100644 src/include/executor/svariableReceiver.h
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 2bc8de3e28b..5dea8ca531b 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9831,6 +9831,19 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcreate_lsn</structfield> <type>pg_lsn</type>
+ </para>
+ <para>
+ LSN of the transaction where the variable was created.
+ <structfield>varcreate_lsn</structfield> and
+ <structfield>oid</structfield> together form the all-time unique
+ identifier (<structfield>oid</structfield> alone is not enough, since
+ object identifiers can get reused).
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>varname</structfield> <type>name</type>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 6a493c2f561..fce5e72bbf6 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5388,6 +5388,67 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
The session variable holds value in session memory. This value is private
to each session and is released when the session ends.
</para>
+
+ <para>
+ The value of a session variable is set with the SQL statement
+ <command>LET</command>. The value of a session variable can be retrieved
+ with the SQL statement <command>SELECT</command>.
+<programlisting>
+CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
+</programlisting>
+
+ or
+
+<programlisting>
+CREATE VARIABLE public.current_user_id AS integer;
+GRANT SELECT ON VARIABLE public.current_user_id TO PUBLIC;
+LET current_user_id = (SELECT id FROM users WHERE usename = session_user);
+SELECT current_user_id;
+</programlisting>
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a variable's value returns a <literal>NULL</literal>, unless its value has
+ been set to something else in the current session using the
+ <command>LET</command> command. Session variables are not transactional:
+ any changes made to the value of a session variable in a transaction won't
+ be undone if the transaction is rolled back (just like variables in
+ procedural languages). Session variables themselves are persistent, but
+ their values are neither persistent nor shared (like the content of
+ temporary tables).
+ </para>
+
+ <para>
+ Inside a query or an expression, a session variable can be
+ <quote>shadowed</quote> by a column with the same name. Similarly, the
+ name of a function or procedure argument or a PL/pgSQL variable (see
+ <xref linkend="plpgsql-declarations"/>) can shadow a session variable
+ in the routine's body. Such collisions of identifiers can be resolved
+ by using qualified identifiers: Session variables can be qualified with
+ the schema name, columns can use table aliases, routine variables can use
+ block labels, and routine arguments can use the routine name.
+<programlisting>
+CREATE VARIABLE name AS text;
+LET name = 'John';
+
+CREATE TABLE foo(name text);
+INSERT INTO foo VALUES('Alice');
+
+-- variable name is shadowed
+SELECT name FROM foo;
+</programlisting>
+
+ which returns:
+
+<programlisting>
+ name
+-------
+ Alice
+</programlisting>
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 988a772e82d..fb99aa75d56 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25847,8 +25847,8 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
't' for <literal>TABLESPACE</literal>,
'F' for <literal>FOREIGN DATA WRAPPER</literal>,
'S' for <literal>FOREIGN SERVER</literal>,
- or
- 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal>.
+ 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal> or
+ 'V' for <literal>SESSION VARIABLE</literal>.
</para></entry>
</row>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index 83b13f98f28..2d13dcea4ef 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1714,8 +1714,9 @@
<para>
A persistent database object that holds a value in session memory. This
value is private to each session and is released when the session ends.
- Read or write access to session variables is controlled by privileges,
- similar to other database objects.
+ The default value of the session variable is null. Read or write access
+ to session variables is controlled by privileges, similar to other database
+ objects.
</para>
<para>
For more information, see <xref linkend="ddl-session-variables"/>.
diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index 1ce9abf86f5..683dede6adc 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -515,6 +515,12 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
Plan nodes that reference a correlated <literal>SubPlan</literal>.
</para>
</listitem>
+
+ <listitem>
+ <para>
+ Plan nodes that use a session variable.
+ </para>
+ </listitem>
</itemizedlist>
<sect2 id="parallel-labeling">
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index e937491e6b8..1e4c43b8b61 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -6036,6 +6036,20 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE;
</programlisting>
</para>
</sect3>
+
+ <sect3 id="plpgsql-porting-package-variables">
+ <title><command>Packages and package variables</command></title>
+
+ <para>
+ The <application>PL/pgSQL</application> language has no packages, and
+ therefore no package variables or package constants.
+ You can consider translating an Oracle package into a schema in
+ <productname>PostgreSQL</productname>. Package functions and procedures
+ would then become functions and procedures in that schema, and package
+ variables could be translated to session variables in that schema.
+ (see <xref linkend="ddl-session-variables"/>).
+ </para>
+ </sect3>
</sect2>
<sect2 id="plpgsql-porting-appendix">
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index 2f67de3e21b..cc3bd5ab540 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -158,6 +158,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY grant SYSTEM "grant.sgml">
<!ENTITY importForeignSchema SYSTEM "import_foreign_schema.sgml">
<!ENTITY insert SYSTEM "insert.sgml">
+<!ENTITY let SYSTEM "let.sgml">
<!ENTITY listen SYSTEM "listen.sgml">
<!ENTITY load SYSTEM "load.sgml">
<!ENTITY lock SYSTEM "lock.sgml">
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
index 96d2586423e..221a699469b 100644
--- a/doc/src/sgml/ref/alter_variable.sgml
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -173,6 +173,7 @@ ALTER VARIABLE boo SET SCHEMA private;
<simplelist type="inline">
<member><xref linkend="sql-createvariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
</refentry>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index 6e988f2e472..cd9ff63975a 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -120,9 +120,11 @@ CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceab
<title>Examples</title>
<para>
- Create an date session variable <literal>var1</literal>:
+ Create a session variable <literal>var1</literal> of data type date:
<programlisting>
CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
</programlisting>
</para>
@@ -143,6 +145,7 @@ CREATE VARIABLE var1 AS date;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
index 5bdb3560f0b..67988b5fcd8 100644
--- a/doc/src/sgml/ref/drop_variable.sgml
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -111,6 +111,7 @@ DROP VARIABLE var1;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/let.sgml b/doc/src/sgml/ref/let.sgml
new file mode 100644
index 00000000000..00f9bea91fe
--- /dev/null
+++ b/doc/src/sgml/ref/let.sgml
@@ -0,0 +1,96 @@
+<!--
+doc/src/sgml/ref/let.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-let">
+ <indexterm zone="sql-let">
+ <primary>LET</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>changing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>LET</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>LET</refname>
+ <refpurpose>change a session variable's value</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+LET <replaceable class="parameter">session_variable</replaceable> = <replaceable class="parameter">sql_expression</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>LET</command> command assigns a value to the specified session
+ variable.
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">session_variable</replaceable></term>
+ <listitem>
+ <para>
+ The name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">sql_expression</replaceable></term>
+ <listitem>
+ <para>
+ An arbitrary SQL expression. The result must be of a data type that can
+ be cast to the type of the session variable in an assignment.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+<programlisting>
+CREATE VARIABLE myvar AS integer;
+LET myvar = 10;
+LET myvar = (SELECT sum(val) FROM tab);
+</programlisting>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>LET</command> is a <productname>PostgreSQL</productname>
+ extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index 25578f3946c..13e4adc5df3 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -186,6 +186,7 @@
&grant;
&importForeignSchema;
&insert;
+ &let;
&listen;
&load;
&lock;
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 9e0f648b74f..90c9e8bb254 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1864,6 +1864,11 @@ find_expr_references_walker(Node *node,
{
Param *param = (Param *) node;
+ /* a variable parameter depends on the session variable */
+ if (param->paramkind == PARAM_VARIABLE)
+ add_object_address(VariableRelationId, param->paramvarid, 0,
+ context->addrs);
+
/* A parameter must depend on the parameter's datatype */
add_object_address(TypeRelationId, param->paramtype, 0,
context->addrs);
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 4307cad15c7..beafee2a341 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -3497,6 +3497,295 @@ NamesFromList(List *names)
return result;
}
+/* -----
+ * IdentifyVariable - try to find a variable from a list of identifiers
+ *
+ * Returns the OID of the variable found, or InvalidOid.
+ *
+ * "names" is a list of up to four identifiers; possible meanings are:
+ * - variable (searched on the search_path)
+ * - schema.variable
+ * - variable.attribute (searched on the search_path)
+ * - schema.variable.attribute
+ * - database.schema.variable
+ * - database.schema.variable.attribute
+ *
+ * If there is more than one way to identify a variable, "not_unique" will be
+ * set to true.
+ *
+ * Unless "noerror" is true, an error is raised if there are more than four
+ * identifiers in the list, or if the named database is not the current one.
+ * This is useful if we want to identify a shadowed variable.
+ *
+ * If an attribute is identified, it is stored in "attrname", otherwise the
+ * parameter is set to NULL.
+ *
+ * The identified session variable will be locked with an AccessShareLock.
+ * -----
+ */
+Oid
+IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror)
+{
+ Oid varid = InvalidOid;
+ Oid old_varid = InvalidOid;
+ uint64 inval_count;
+ bool retry = false;
+
+ /*
+ * DDL operations can change the results of a name lookup. Since all such
+ * operations will generate invalidation messages, we keep track of
+ * whether any such messages show up while we're performing the operation,
+ * and retry until either (1) no more invalidation messages show up or (2)
+ * the answer doesn't change.
+ */
+ for (;;)
+ {
+ Node *field1 = NULL;
+ Node *field2 = NULL;
+ Node *field3 = NULL;
+ Node *field4 = NULL;
+ char *a = NULL;
+ char *b = NULL;
+ char *c = NULL;
+ char *d = NULL;
+ Oid varoid_without_attr = InvalidOid;
+ Oid varoid_with_attr = InvalidOid;
+
+ *not_unique = false;
+ *attrname = NULL;
+ varid = InvalidOid;
+
+ inval_count = SharedInvalidMessageCounter;
+
+ switch (list_length(names))
+ {
+ case 1:
+ field1 = linitial(names);
+
+ Assert(IsA(field1, String));
+
+ varid = LookupVariable(NULL, strVal(field1), true);
+ break;
+
+ case 2:
+ field1 = linitial(names);
+ field2 = lsecond(names);
+
+ Assert(IsA(field1, String));
+ a = strVal(field1);
+
+ if (IsA(field2, String))
+ {
+ /* when both fields are of string type */
+ b = strVal(field2);
+
+ /*
+ * a.b can mean "schema"."variable" or
+ * "variable"."attribute". Check both variants, and
+ * returns InvalidOid with not_unique flag, when both
+ * interpretations are possible.
+ */
+ varoid_without_attr = LookupVariable(a, b, true);
+ varoid_with_attr = LookupVariable(NULL, a, true);
+ }
+ else
+ {
+ /* the last field of list can be star too */
+ Assert(IsA(field2, A_Star));
+
+ /*
+ * The syntax ident.* is used only by relation aliases,
+ * and then this identifier cannot be a reference to
+ * session variable.
+ */
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = b;
+ varid = varoid_with_attr;
+ }
+ break;
+
+ case 3:
+ {
+ bool field1_is_catalog = false;
+
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+
+ if (IsA(field3, String))
+ {
+ c = strVal(field3);
+
+ /*
+ * a.b.c can mean catalog.schema.variable or
+ * schema.variable.attribute.
+ *
+ * Check both variants, and set not_unique flag, when
+ * both interpretations are possible.
+ *
+ * When third node is star, only possible
+ * interpretation is schema.variable.*, but this
+ * pattern is not supported now.
+ */
+ varoid_with_attr = LookupVariable(a, b, true);
+
+ /*
+ * check pattern catalog.schema.variable only when
+ * there is possibility to success.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) == 0)
+ {
+ field1_is_catalog = true;
+ varoid_without_attr = LookupVariable(b, c, true);
+ }
+ }
+ else
+ {
+ Assert(IsA(field3, A_Star));
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = c;
+ varid = varoid_with_attr;
+ }
+
+ /*
+ * When we didn't find variable, we can (when it is
+ * allowed) raise cross-database reference error.
+ */
+ if (!OidIsValid(varid) && !noerror && !field1_is_catalog)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+ break;
+
+ case 4:
+ {
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+ field4 = lfourth(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+ Assert(IsA(field3, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+ c = strVal(field3);
+
+ /*
+ * In this case, "a" is used as catalog name - check it.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) != 0)
+ {
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+
+ if (IsA(field4, String))
+ {
+ d = strVal(field4);
+ }
+ else
+ {
+ Assert(IsA(field4, A_Star));
+ return InvalidOid;
+ }
+
+ *attrname = d;
+ varid = LookupVariable(b, c, true);
+ }
+ break;
+
+ default:
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper qualified name (too many dotted names): %s",
+ NameListToString(names))));
+ return InvalidOid;
+ }
+
+ /*
+ * If, upon retry, we get back the same OID we did last time, then the
+ * invalidation messages we processed did not change the final answer.
+ * So we're done.
+ *
+ * If we got a different OID, we've locked the variable that used to
+ * have this name rather than the one that does now. So release the
+ * lock.
+ */
+ if (retry)
+ {
+ if (old_varid == varid)
+ break;
+
+ if (OidIsValid(old_varid))
+ UnlockDatabaseObject(VariableRelationId, old_varid, 0, AccessShareLock);
+ }
+
+ /*
+ * Lock the variable. This will also accept any pending invalidation
+ * messages. If we got back InvalidOid, indicating not found, then
+ * there's nothing to lock, but we accept invalidation messages
+ * anyway, to flush any negative catcache entries that may be
+ * lingering.
+ */
+ if (!OidIsValid(varid))
+ AcceptInvalidationMessages();
+ else
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ /*
+ * If no invalidation message were processed, we're done!
+ */
+ if (inval_count == SharedInvalidMessageCounter)
+ break;
+
+ retry = true;
+ old_varid = varid;
+ varid = InvalidOid;
+ }
+
+ return varid;
+}
+
/*
* DeconstructQualifiedName
* Given a possibly-qualified name expressed as a list of String nodes,
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 29d967a2d5b..bb445e9434b 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -26,6 +26,7 @@
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
+#include "utils/pg_lsn.h"
#include "utils/syscache.h"
static ObjectAddress create_variable(const char *varName,
@@ -101,6 +102,7 @@ create_variable(const char *varName,
varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varcreate_lsn - 1] = LSNGetDatum(GetXLogInsertRecPtr());
values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile
index cb2fbdc7c60..aee40e7bd59 100644
--- a/src/backend/commands/Makefile
+++ b/src/backend/commands/Makefile
@@ -53,6 +53,7 @@ OBJS = \
schemacmds.o \
seclabel.o \
sequence.o \
+ session_variable.o \
statscmds.o \
subscriptioncmds.o \
tablecmds.o \
diff --git a/src/backend/commands/meson.build b/src/backend/commands/meson.build
index dd4cde41d32..101c8d75dd1 100644
--- a/src/backend/commands/meson.build
+++ b/src/backend/commands/meson.build
@@ -41,6 +41,7 @@ backend_sources += files(
'schemacmds.c',
'seclabel.c',
'sequence.c',
+ 'session_variable.c',
'statscmds.c',
'subscriptioncmds.c',
'tablecmds.c',
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index bf7d2b2309f..56b3d8cb91d 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -342,6 +342,16 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
i++;
}
+ /*
+ * The arguments of EXECUTE are evaluated by a direct expression
+ * executor call. This mode doesn't support session variables yet.
+ * It will be enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
/* Prepare the expressions for execution */
exprstates = ExecPrepareExprList(params, estate);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
new file mode 100644
index 00000000000..d2891a1dcb7
--- /dev/null
+++ b/src/backend/commands/session_variable.c
@@ -0,0 +1,529 @@
+/*-------------------------------------------------------------------------
+ *
+ * session_variable.c
+ * session variable creation/manipulation commands
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/commands/session_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "rewrite/rewriteHandler.h"
+#include "storage/lmgr.h"
+#include "storage/proc.h"
+#include "tcop/tcopprot.h"
+#include "utils/builtins.h"
+#include "utils/datum.h"
+#include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/snapmgr.h"
+#include "utils/syscache.h"
+
+/*
+ * The values of session variables are stored in the backend's private memory
+ * in the dedicated memory context SVariableMemoryContext in binary format.
+ * They are stored in the "sessionvars" hash table, whose key is the OID of the
+ * variable. However, the OID is not good enough to identify a session
+ * variable: concurrent sessions could drop the session variable and create a
+ * new one, which could be assigned the same OID. To ensure that the values
+ * stored in memory and the catalog definition match, we also keep track of
+ * the "create_lsn". Before any access to the variable values, we need to
+ * check if the LSN stored in memory matches the LSN in the catalog. If there
+ * is a mismatch between the LSNs, or if the OID is not present in pg_variable
+ * at all, the value stored in memory is released.
+ */
+typedef struct SVariableData
+{
+ Oid varid; /* pg_variable OID of the variable (hash key) */
+ XLogRecPtr create_lsn;
+
+ bool isnull;
+ Datum value;
+
+ Oid typid;
+ int16 typlen;
+ bool typbyval;
+
+ bool is_domain;
+
+ /*
+ * domain_check_extra holds cached domain metadata. This "extra" is
+ * usually stored in fn_mcxt. We do not have access to that memory context
+ * for session variables, but we can use TopTransactionContext instead.
+ * A fresh value is forced when we detect we are in a different transaction
+ * (the local transaction ID differs from domain_check_extra_lxid).
+ */
+ void *domain_check_extra;
+ LocalTransactionId domain_check_extra_lxid;
+
+ /*
+ * Stored value and type description can be outdated when we receive a
+ * sinval message. We then have to check if the stored data are still
+ * trustworthy.
+ */
+ bool is_valid;
+
+ uint32 hashvalue; /* used for pairing sinval message */
+} SVariableData;
+
+typedef SVariableData *SVariable;
+
+static HTAB *sessionvars = NULL; /* hash table for session variables */
+
+static MemoryContext SVariableMemoryContext = NULL;
+
+/*
+ * Callback function for session variable invalidation.
+ */
+static void
+pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
+
+ Assert(sessionvars);
+
+ /*
+ * If the hashvalue is not specified, we have to recheck all currently
+ * used session variables. Since we can't tell the exact session variable
+ * from its hashvalue, we have to iterate over all items in the hash bucket.
+ */
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (hashvalue == 0 || svar->hashvalue == hashvalue)
+ {
+ svar->is_valid = false;
+ }
+ }
+}
+
+/*
+ * Release stored value, free memory
+ */
+static void
+free_session_variable_value(SVariable svar)
+{
+ /* clean the current value */
+ if (!svar->isnull)
+ {
+ if (!svar->typbyval)
+ pfree(DatumGetPointer(svar->value));
+
+ svar->isnull = true;
+ }
+
+ svar->value = (Datum) 0;
+}
+
+/*
+ * Returns true when the entry in pg_variable is consistent with the given
+ * session variable.
+ */
+static bool
+is_session_variable_valid(SVariable svar)
+{
+ HeapTuple tp;
+ bool result = false;
+
+ Assert(OidIsValid(svar->varid));
+
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ /*
+ * The OID alone is not enough as an unique identifier, because OID
+ * values get recycled, and a new session variable could have got
+ * the same OID. We do a second check against the 64-bit LSN when
+ * the variable was created.
+ */
+ if (svar->create_lsn == ((Form_pg_variable) GETSTRUCT(tp))->varcreate_lsn)
+ result = true;
+
+ ReleaseSysCache(tp);
+ }
+
+ return result;
+}
+
+/*
+ * Initialize attributes cached in "svar"
+ */
+static void
+setup_session_variable(SVariable svar, Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ Assert(OidIsValid(varid));
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ svar->varid = varid;
+ svar->create_lsn = varform->varcreate_lsn;
+
+ svar->typid = varform->vartype;
+
+ get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval);
+
+ svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
+ svar->domain_check_extra = NULL;
+ svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+
+ svar->isnull = true;
+ svar->value = (Datum) 0;
+
+ svar->is_valid = true;
+
+ svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ ReleaseSysCache(tup);
+}
+
+/*
+ * Assign a new value to the session variable. It is copied to
+ * SVariableMemoryContext if necessary.
+ *
+ * If any error happens, the existing value won't be modified.
+ */
+static void
+set_session_variable(SVariable svar, Datum value, bool isnull)
+{
+ Datum newval;
+ SVariableData locsvar,
+ *_svar;
+
+ Assert(svar);
+ Assert(!isnull || value == (Datum) 0);
+
+ /*
+ * Use typbyval, typbylen from session variable only when they are
+ * trustworthy (the invalidation message was not accepted for this
+ * variable). If the variable might be invalid, force setup.
+ *
+ * Do not overwrite the passed session variable until we can be certain
+ * that no error can be thrown.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(&locsvar, svar->varid);
+ _svar = &locsvar;
+ }
+ else
+ _svar = svar;
+
+ if (!isnull)
+ {
+ MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
+
+ newval = datumCopy(value, _svar->typbyval, _svar->typlen);
+
+ MemoryContextSwitchTo(oldcxt);
+ }
+ else
+ newval = value;
+
+ free_session_variable_value(svar);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ svar->varid);
+
+ /* no more error expected, so we can overwrite the old variable now */
+ if (svar != _svar)
+ memcpy(svar, _svar, sizeof(SVariableData));
+
+ svar->value = newval;
+ svar->isnull = isnull;
+}
+
+/*
+ * Create the hash table for storing session variables.
+ */
+static void
+create_sessionvars_hashtables(void)
+{
+ HASHCTL vars_ctl;
+
+ Assert(!sessionvars);
+
+ if (!SVariableMemoryContext)
+ {
+ /* read sinval messages */
+ CacheRegisterSyscacheCallback(VARIABLEOID,
+ pg_variable_cache_callback,
+ (Datum) 0);
+
+ /* we need our own long-lived memory context */
+ SVariableMemoryContext =
+ AllocSetContextCreate(TopMemoryContext,
+ "session variables",
+ ALLOCSET_START_SMALL_SIZES);
+ }
+
+ memset(&vars_ctl, 0, sizeof(vars_ctl));
+ vars_ctl.keysize = sizeof(Oid);
+ vars_ctl.entrysize = sizeof(SVariableData);
+ vars_ctl.hcxt = SVariableMemoryContext;
+
+ sessionvars = hash_create("Session variables", 64, &vars_ctl,
+ HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+}
+
+/*
+ * Search a session variable in the hash table given its OID. If it
+ * doesn't exist, then insert it there.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the
+ * session variable until the end of the transaction.
+ */
+static SVariable
+get_session_variable(Oid varid)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect the used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (found)
+ {
+ if (!svar->is_valid)
+ {
+ /*
+ * If there was an invalidation message, the variable might still be
+ * valid, but we have to check with the system catalog.
+ */
+ if (is_session_variable_valid(svar))
+ svar->is_valid = true;
+ else
+ /* if the value cannot be validated, we have to discard it */
+ free_session_variable_value(svar);
+ }
+ }
+ else
+ svar->is_valid = false;
+
+ /*
+ * Force setup for not yet initialized variables or variables that cannot
+ * be validated.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ varid);
+ }
+
+ /* ensure the returned data is still of the correct domain */
+ if (svar->is_domain)
+ {
+ /*
+ * Store "extra" for domain_check() in TopTransactionContext. When we
+ * are in a new transaction, domain_check_extra cache is not valid any
+ * more.
+ */
+ if (svar->domain_check_extra_lxid != MyProc->vxid.lxid)
+ svar->domain_check_extra = NULL;
+
+ domain_check(svar->value, svar->isnull,
+ svar->typid, &svar->domain_check_extra,
+ TopTransactionContext);
+
+ svar->domain_check_extra_lxid = MyProc->vxid.lxid;
+ }
+
+ return svar;
+}
+
+/*
+ * Store the given value in a session variable in the cache.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the session
+ * variable until the end of the transaction.
+ */
+void
+SetSessionVariable(Oid varid, Datum value, bool isNull)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (!found)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ varid);
+ }
+
+ /* if this fails, it won't change the stored value */
+ set_session_variable(svar, value, isNull);
+}
+
+/*
+ * Returns a copy of the value stored in a variable.
+ */
+static inline Datum
+copy_session_variable_value(SVariable svar, bool *isNull)
+{
+ Datum value;
+
+ /* force copy of non NULL value */
+ if (!svar->isnull)
+ {
+ value = datumCopy(svar->value, svar->typbyval, svar->typlen);
+ *isNull = false;
+ }
+ else
+ {
+ value = (Datum) 0;
+ *isNull = true;
+ }
+
+ return value;
+}
+
+/*
+ * Returns a copy of the value of the session variable (in the current memory
+ * context). The caller is responsible for permission checks.
+ */
+Datum
+GetSessionVariable(Oid varid, bool *isNull)
+{
+ SVariable svar;
+
+ svar = get_session_variable(varid);
+
+ /*
+ * Although "svar" is freshly validated in this point, svar->is_valid can
+ * be false, if an invalidation message was processed during the domain check.
+ * But the variable and all its dependencies are locked now, so we don't need
+ * to repeat the validation.
+ */
+ return copy_session_variable_value(svar, isNull);
+}
+
+/*
+ * Assign the result of the evaluated expression to the session variable
+ */
+void
+ExecuteLetStmt(ParseState *pstate,
+ LetStmt *stmt,
+ ParamListInfo params,
+ QueryEnvironment *queryEnv,
+ QueryCompletion *qc)
+{
+ Query *query = castNode(Query, stmt->query);
+ List *rewritten;
+ DestReceiver *dest;
+ AclResult aclresult;
+ PlannedStmt *plan;
+ QueryDesc *queryDesc;
+ Oid varid = query->resultVariable;
+
+ Assert(OidIsValid(varid));
+
+ /* do we have permission to write to the session variable? */
+ aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid));
+
+ /* create a dest receiver for LET */
+ dest = CreateVariableDestReceiver(varid);
+
+ /* run the query rewriter */
+ query = copyObject(query);
+
+ rewritten = QueryRewrite(query);
+
+ Assert(list_length(rewritten) == 1);
+
+ query = linitial_node(Query, rewritten);
+ Assert(query->commandType == CMD_SELECT);
+
+ /* plan the query */
+ plan = pg_plan_query(query, pstate->p_sourcetext,
+ CURSOR_OPT_PARALLEL_OK, params);
+
+ /*
+ * Use a snapshot with an updated command ID to ensure this query sees the
+ * results of any previously executed queries. (This could only matter if
+ * the planner executed an allegedly-stable function that changed the
+ * database contents, but let's do it anyway to be parallel to the EXPLAIN
+ * code path.)
+ */
+ PushCopiedSnapshot(GetActiveSnapshot());
+ UpdateActiveSnapshotCommandId();
+
+ /* create a QueryDesc, redirecting output to our tuple receiver */
+ queryDesc = CreateQueryDesc(plan, NULL, pstate->p_sourcetext,
+ GetActiveSnapshot(), InvalidSnapshot,
+ dest, params, queryEnv, 0);
+
+ /* call ExecutorStart to prepare the plan for execution */
+ ExecutorStart(queryDesc, 0);
+
+ /*
+ * Run the plan to completion. The result should be only one row. To
+ * check if there are too many result rows, we try to fetch two.
+ */
+ ExecutorRun(queryDesc, ForwardScanDirection, 2L);
+
+ /* save the rowcount if we're given a QueryCompletion to fill */
+ if (qc)
+ SetQueryCompletion(qc, CMDTAG_LET, queryDesc->estate->es_processed);
+
+ /* and clean up */
+ ExecutorFinish(queryDesc);
+ ExecutorEnd(queryDesc);
+
+ FreeQueryDesc(queryDesc);
+
+ PopActiveSnapshot();
+}
diff --git a/src/backend/executor/Makefile b/src/backend/executor/Makefile
index 11118d0ce02..71248a34f26 100644
--- a/src/backend/executor/Makefile
+++ b/src/backend/executor/Makefile
@@ -76,6 +76,7 @@ OBJS = \
nodeWindowAgg.o \
nodeWorktablescan.o \
spi.o \
+ svariableReceiver.o \
tqueue.o \
tstoreReceiver.o
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index f1569879b52..e4e9de335b5 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -1041,6 +1041,38 @@ ExecInitExprRec(Expr *node, ExprState *state,
scratch.d.param.paramtype = param->paramtype;
ExprEvalPushStep(state, &scratch);
break;
+
+ case PARAM_VARIABLE:
+ {
+ int es_num_session_variables = 0;
+ SessionVariableValue *es_session_variables = NULL;
+ SessionVariableValue *var;
+
+ if (state->parent && state->parent->state)
+ {
+ es_session_variables = state->parent->state->es_session_variables;
+ es_num_session_variables = state->parent->state->es_num_session_variables;
+ }
+
+ Assert(es_session_variables);
+
+ /* parameter sanity checks */
+ if (param->paramid >= es_num_session_variables)
+ elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
+
+ var = &es_session_variables[param->paramid];
+
+ /*
+ * In this case, pass the value like a
+ * constant.
+ */
+ scratch.opcode = EEOP_CONST;
+ scratch.d.constval.value = var->value;
+ scratch.d.constval.isnull = var->isnull;
+ ExprEvalPushStep(state, &scratch);
+ }
+ break;
+
case PARAM_EXTERN:
/*
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 2da848970be..3161ac9f5f7 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -43,7 +43,9 @@
#include "access/xact.h"
#include "catalog/namespace.h"
#include "catalog/partition.h"
+#include "catalog/pg_variable.h"
#include "commands/matview.h"
+#include "commands/session_variable.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/execPartition.h"
@@ -206,6 +208,70 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
Assert(queryDesc->sourceText != NULL);
estate->es_sourceText = queryDesc->sourceText;
+ /*
+ * The executor doesn't work with session variables directly. Values of
+ * related session variables are copied to a dedicated array, and this array
+ * is passed to the executor. This array is stable "snapshot" of values of
+ * used session variables. There are three benefits of this strategy:
+ *
+ * - consistency with external parameters and plpgsql variables,
+ *
+ * - session variables can be parallel safe,
+ *
+ * - we don't need make fresh copy for any read of session variable
+ * (this is necessary because the internally the session variable can
+ * be changed inside query execution time, and then a reference to
+ * previously returned value can be corrupted).
+ */
+ if (queryDesc->plannedstmt->sessionVariables)
+ {
+ int nSessionVariables;
+ int i = 0;
+
+ /*
+ * In this case, the query uses session variables, but we have to
+ * prepare the array with passed values (of used session variables)
+ * first.
+ */
+ Assert(!IsParallelWorker());
+ nSessionVariables = list_length(queryDesc->plannedstmt->sessionVariables);
+
+ /* create the array used for passing values of used session variables */
+ estate->es_session_variables = (SessionVariableValue *)
+ palloc(nSessionVariables * sizeof(SessionVariableValue));
+
+ /* fill the array */
+ foreach_oid(varid, queryDesc->plannedstmt->sessionVariables)
+ {
+ /*
+ * Permission check should be executed on all explicitly used
+ * variables in the query. For implicitly used variable
+ * (like base node of assignment indirect) we cannot do permission
+ * check, because we need read the value (and user can have
+ * only UPDATE variable). In this case the permission check
+ * is executed in write time.
+ */
+ if (varid != queryDesc->plannedstmt->exclSelectPermCheckVarid)
+ {
+ AclResult aclresult;
+
+ aclresult = object_aclcheck(VariableRelationId, varid,
+ GetUserId(), ACL_SELECT);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE,
+ get_session_variable_name(varid));
+ }
+
+ estate->es_session_variables[i].value =
+ GetSessionVariable(varid,
+ &estate->es_session_variables[i].isnull);
+
+ i++;
+ }
+
+ estate->es_num_session_variables = nSessionVariables;
+ }
+
/*
* Fill in the query environment, if any, from queryDesc.
*/
diff --git a/src/backend/executor/meson.build b/src/backend/executor/meson.build
index 2cea41f8771..491092fcc4c 100644
--- a/src/backend/executor/meson.build
+++ b/src/backend/executor/meson.build
@@ -64,6 +64,7 @@ backend_sources += files(
'nodeWindowAgg.c',
'nodeWorktablescan.c',
'spi.c',
+ 'svariableReceiver.c',
'tqueue.c',
'tstoreReceiver.c',
)
diff --git a/src/backend/executor/svariableReceiver.c b/src/backend/executor/svariableReceiver.c
new file mode 100644
index 00000000000..c6163fb36f6
--- /dev/null
+++ b/src/backend/executor/svariableReceiver.c
@@ -0,0 +1,172 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.c
+ * An implementation of DestReceiver that stores the result value in
+ * a session variable.
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/executor/svariableReceiver.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "miscadmin.h"
+
+#include "access/detoast.h"
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "storage/lock.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+/*
+ * This DestReceiver is used by the LET command for storing the result to a
+ * session variable. The result has to have only one tuple with only one
+ * non-deleted attribute. The row counter (field "rows") is incremented
+ * after receiving a row, and an error is raised when there are no rows or
+ * there are more than one received rows. A received tuple cannot to have
+ * deleted attributes. The value is detoasted before storing it in the
+ * session variable.
+ */
+typedef struct
+{
+ DestReceiver pub;
+ Oid varid;
+ bool need_detoast; /* do we need to detoast the attribute? */
+ int rows; /* row counter */
+} SVariableState;
+
+/*
+ * Prepare to receive tuples from executor.
+ */
+static void
+svariableStartupReceiver(DestReceiver *self, int operation, TupleDesc typeinfo)
+{
+ SVariableState *myState = (SVariableState *) self;
+ LOCKTAG locktag PG_USED_FOR_ASSERTS_ONLY;
+ Form_pg_attribute attr;
+ Oid typid PG_USED_FOR_ASSERTS_ONLY;
+ Oid collid PG_USED_FOR_ASSERTS_ONLY;
+ int32 typmod PG_USED_FOR_ASSERTS_ONLY;
+
+ Assert(myState->pub.mydest == DestVariable);
+ Assert(OidIsValid(myState->varid));
+ Assert(SearchSysCacheExists1(VARIABLEOID, myState->varid));
+ Assert(typeinfo->natts == 1);
+
+#ifdef USE_ASSERT_CHECKING
+
+ SET_LOCKTAG_OBJECT(locktag,
+ MyDatabaseId,
+ VariableRelationId,
+ myState->varid,
+ 0);
+
+ Assert(LockHeldByMe(&locktag, AccessShareLock, false));
+
+#endif
+
+ attr = TupleDescAttr(typeinfo, 0);
+
+ Assert(!attr->attisdropped);
+
+#ifdef USE_ASSERT_CHECKING
+
+ get_session_variable_type_typmod_collid(myState->varid,
+ &typid,
+ &typmod,
+ &collid);
+
+ Assert(attr->atttypid == typid);
+ Assert(attr->atttypmod < 0 || attr->atttypmod == typmod);
+
+#endif
+
+ myState->need_detoast = attr->attlen == -1;
+ myState->rows = 0;
+}
+
+/*
+ * Receive a tuple from the executor and store it in the session variable.
+ */
+static bool
+svariableReceiveSlot(TupleTableSlot *slot, DestReceiver *self)
+{
+ SVariableState *myState = (SVariableState *) self;
+ Datum value;
+ bool isnull;
+ bool freeval = false;
+
+ /* make sure the tuple is fully deconstructed */
+ slot_getallattrs(slot);
+
+ value = slot->tts_values[0];
+ isnull = slot->tts_isnull[0];
+
+ if (myState->need_detoast && !isnull && VARATT_IS_EXTERNAL(DatumGetPointer(value)))
+ {
+ value = PointerGetDatum(detoast_external_attr((struct varlena *)
+ DatumGetPointer(value)));
+ freeval = true;
+ }
+
+ myState->rows += 1;
+
+ if (myState->rows > 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_TOO_MANY_ROWS),
+ errmsg("expression returned more than one row")));
+
+ SetSessionVariable(myState->varid, value, isnull);
+
+ if (freeval)
+ pfree(DatumGetPointer(value));
+
+ return true;
+}
+
+/*
+ * Clean up at end of the executor run
+ */
+static void
+svariableShutdownReceiver(DestReceiver *self)
+{
+ if (((SVariableState *) self)->rows == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_NO_DATA_FOUND),
+ errmsg("expression returned no rows")));
+}
+
+/*
+ * Destroy the receiver when we are done with it
+ */
+static void
+svariableDestroyReceiver(DestReceiver *self)
+{
+ pfree(self);
+}
+
+/*
+ * Initially create a DestReceiver object.
+ */
+DestReceiver *
+CreateVariableDestReceiver(Oid varid)
+{
+ SVariableState *self = (SVariableState *) palloc0(sizeof(SVariableState));
+
+ self->pub.receiveSlot = svariableReceiveSlot;
+ self->pub.rStartup = svariableStartupReceiver;
+ self->pub.rShutdown = svariableShutdownReceiver;
+ self->pub.rDestroy = svariableDestroyReceiver;
+ self->pub.mydest = DestVariable;
+
+ self->varid = varid;
+
+ return (DestReceiver *) self;
+}
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f1..d8fc3d9fa69 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4375,6 +4375,16 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_LetStmt:
+ {
+ LetStmt *stmt = (LetStmt *) node;
+
+ if (WALK(stmt->target))
+ return true;
+ if (WALK(stmt->query))
+ return true;
+ }
+ break;
case T_PLAssignStmt:
{
PLAssignStmt *stmt = (PLAssignStmt *) node;
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 566ce5b3cb4..4a92888308a 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -338,6 +338,21 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
glob->lastPlanNodeId = 0;
glob->transientPlan = false;
glob->dependsOnRole = false;
+ glob->sessionVariables = NIL;
+
+ /*
+ * The (session) result variable should be stored to global, because
+ * it is not set in subquery. When this variable is used other than
+ * in base node of assignment indirection, we need to check the access
+ * rights (and then we need to detect this situation). The variable used
+ * like base node cannot be different than target (result) variable.
+ * Because we know the result variable before planner invocation, we
+ * can simply search of usage just this variable, and we don't need to
+ * to wait until the end of planning when we know basenodeSessionVarid.
+ */
+ glob->resultVariable = parse->resultVariable;
+ glob->basenodeSessionVarid = InvalidOid;
+ glob->basenodeSessionVarSelectCheck = false;
/*
* Assess whether it's feasible to use parallel mode for this query. We
@@ -576,6 +591,20 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
result->paramExecTypes = glob->paramExecTypes;
/* utilityStmt should be null, but we might as well copy it */
result->utilityStmt = parse->utilityStmt;
+
+ result->sessionVariables = glob->sessionVariables;
+
+ /*
+ * The session variable used (and only used) like base node
+ * for assignemnt indirection should be excluded from permission
+ * check.
+ */
+ if (OidIsValid(glob->basenodeSessionVarid) &&
+ (!glob->basenodeSessionVarSelectCheck))
+ result->exclSelectPermCheckVarid = glob->basenodeSessionVarid;
+ else
+ result->exclSelectPermCheckVarid = InvalidOid;
+
result->stmt_location = parse->stmt_location;
result->stmt_len = parse->stmt_len;
@@ -754,6 +783,13 @@ subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root,
*/
pull_up_subqueries(root);
+ /*
+ * Check if some subquery uses a session variable. The flag
+ * hasSessionVariables should be true if the query or some subquery uses a
+ * session variable.
+ */
+ pull_up_has_session_variables(root);
+
/*
* If this is a simple UNION ALL query, flatten it into an appendrel. We
* do this now because it requires applying pull_up_subqueries to the leaf
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 150e9f060ee..d071bd0c559 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -210,6 +210,9 @@ static List *set_returning_clause_references(PlannerInfo *root,
static List *set_windowagg_runcondition_references(PlannerInfo *root,
List *runcondition,
Plan *plan);
+static bool pull_up_has_session_variables_walker(Node *node,
+ PlannerInfo *root);
+static void record_plan_variable_dependency(PlannerInfo *root, Oid varid);
/*****************************************************************************
@@ -1318,6 +1321,50 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
return plan;
}
+/*
+ * Search usage of session variables in subqueries
+ */
+void
+pull_up_has_session_variables(PlannerInfo *root)
+{
+ Query *query = root->parse;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ }
+ else
+ {
+ (void) query_tree_walker(query,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+}
+
+static bool
+pull_up_has_session_variables_walker(Node *node, PlannerInfo *root)
+{
+ if (node == NULL)
+ return false;
+ if (IsA(node, Query))
+ {
+ Query *query = (Query *) node;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ return false;
+ }
+
+ /* recurse into subselects */
+ return query_tree_walker((Query *) node,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+ return expression_tree_walker(node, pull_up_has_session_variables_walker,
+ (void *) root);
+}
+
/*
* set_indexonlyscan_references
* Do set_plan_references processing on an IndexOnlyScan
@@ -2018,8 +2065,9 @@ copyVar(Var *var)
* This is code that is common to all variants of expression-fixing.
* We must look up operator opcode info for OpExpr and related nodes,
* add OIDs from regclass Const nodes into root->glob->relationOids, and
- * add PlanInvalItems for user-defined functions into root->glob->invalItems.
- * We also fill in column index lists for GROUPING() expressions.
+ * add PlanInvalItems for user-defined functions and session variables into
+ * root->glob->invalItems. We also fill in column index lists for GROUPING()
+ * expressions.
*
* We assume it's okay to update opcode info in-place. So this could possibly
* scribble on the planner's input data structures, but it's OK.
@@ -2109,6 +2157,13 @@ fix_expr_common(PlannerInfo *root, Node *node)
g->cols = cols;
}
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ record_plan_variable_dependency(root, p->paramvarid);
+ }
}
/*
@@ -2118,6 +2173,10 @@ fix_expr_common(PlannerInfo *root, Node *node)
* If it's a PARAM_MULTIEXPR, replace it with the appropriate Param from
* root->multiexpr_params; otherwise no change is needed.
* Just for paranoia's sake, we make a copy of the node in either case.
+ *
+ * If it's a PARAM_VARIABLE, then we collect used session variables in
+ * the list root->glob->sessionVariable. Also, assign the parameter's
+ * "paramid" to the parameter's position in that list.
*/
static Node *
fix_param_node(PlannerInfo *root, Param *p)
@@ -2136,6 +2195,62 @@ fix_param_node(PlannerInfo *root, Param *p)
elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid);
return copyObject(list_nth(params, colno - 1));
}
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ int n = 0;
+ bool found = false;
+
+ /* we will modify object */
+ p = (Param *) copyObject(p);
+
+ /*
+ * Now, we can actualize list of session variables, and we can
+ * complete paramid parameter.
+ */
+ foreach_oid(varid, root->glob->sessionVariables)
+ {
+ if (varid == p->paramvarid)
+ {
+ p->paramid = n;
+ found = true;
+ break;
+ }
+ n += 1;
+ }
+
+ if (!found)
+ {
+ root->glob->sessionVariables = lappend_oid(root->glob->sessionVariables,
+ p->paramvarid);
+ p->paramid = n;
+ }
+
+ /*
+ * We do SELECT permission check of all variables used by
+ * the query excluding the variable that is used only as base node
+ * of assignment indirection. The variable id assigned to this param
+ * should be same like resultVariable id, and this param should be
+ * used only once in query. When the variable is referenced by any
+ * other param, we should to do SELECT permission check for this variable
+ * too.
+ */
+ if (p->parambasenode)
+ {
+ Assert(!OidIsValid(root->glob->basenodeSessionVarid));
+ Assert(root->glob->resultVariable == p->paramvarid);
+
+ root->glob->basenodeSessionVarid = p->paramvarid;
+ }
+ else
+ {
+ if (p->paramvarid == root->glob->resultVariable)
+ root->glob->basenodeSessionVarSelectCheck = true;
+ }
+
+ return (Node *) p;
+ }
+
return (Node *) copyObject(p);
}
@@ -2197,7 +2312,10 @@ fix_alternative_subplan(PlannerInfo *root, AlternativeSubPlan *asplan,
* replacing Aggref nodes that should be replaced by initplan output Params,
* choosing the best implementation for AlternativeSubPlans,
* looking up operator opcode info for OpExpr and related nodes,
- * and adding OIDs from regclass Const nodes into root->glob->relationOids.
+ * adding OIDs from regclass Const nodes into root->glob->relationOids,
+ * assigning paramvarid to PARAM_VARIABLE params, and collecting the
+ * OIDs of session variables in the root->glob->sessionVariables list
+ * (paramvarid is the position of the session variable in this list).
*
* 'node': the expression to be modified
* 'rtoffset': how much to increment varnos by
@@ -2219,7 +2337,8 @@ fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec)
root->multiexpr_params != NIL ||
root->glob->lastPHId != 0 ||
root->minmax_aggs != NIL ||
- root->hasAlternativeSubPlans)
+ root->hasAlternativeSubPlans ||
+ root->hasSessionVariables)
{
return fix_scan_expr_mutator(node, &context);
}
@@ -3612,6 +3731,25 @@ record_plan_type_dependency(PlannerInfo *root, Oid typid)
}
}
+/*
+ * Record dependency on a session variable. The variable can be used as a
+ * session variable in an expression list, or as the target of a LET statement.
+ */
+static void
+record_plan_variable_dependency(PlannerInfo *root, Oid varid)
+{
+ PlanInvalItem *inval_item = makeNode(PlanInvalItem);
+
+ /* paramid is still session variable id */
+ inval_item->cacheId = VARIABLEOID;
+ inval_item->hashValue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ /* append this variable to global, register dependency */
+ root->glob->invalItems = lappend(root->glob->invalItems,
+ inval_item);
+}
+
/*
* extract_query_dependencies
* Given a rewritten, but not yet planned, query or queries
@@ -3697,9 +3835,9 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
}
/*
- * Ignore other utility statements, except those (such as EXPLAIN)
- * that contain a parsed-but-not-planned query. For those, we
- * just need to transfer our attention to the contained query.
+ * Ignore other utility statements, except those (such as EXPLAIN
+ * or LET) that contain a parsed-but-not-planned query. For those,
+ * we just need to transfer our attention to the contained query.
*/
query = UtilityContainsQuery(query->utilityStmt);
if (query == NULL)
@@ -3722,6 +3860,10 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
lappend_oid(context->glob->relationOids, rte->relid);
}
+ /* record dependency on the target variable of a LET command */
+ if (OidIsValid(query->resultVariable))
+ record_plan_variable_dependency(context, query->resultVariable);
+
/* And recurse into the query's subexpressions */
return query_tree_walker(query, extract_query_dependencies_walker,
context, 0);
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index 87dc6f56b57..1ebc808a5e6 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -1585,6 +1585,9 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
/* If subquery had any RLS conditions, now main query does too */
parse->hasRowSecurity |= subquery->hasRowSecurity;
+ /* if the subquery had session variables, the main query does too */
+ parse->hasSessionVariables |= subquery->hasSessionVariables;
+
/*
* subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
* hasTargetSRFs, so no work needed on those flags
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 26a3e050086..23cafc73c3b 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -24,6 +24,7 @@
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "commands/session_variable.h"
#include "executor/executor.h"
#include "executor/functions.h"
#include "funcapi.h"
@@ -936,6 +937,13 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
if (param->paramkind == PARAM_EXTERN)
return false;
+ /* we don't support passing session variables to workers */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
+ return true;
+ }
+
if (param->paramkind != PARAM_EXEC ||
!list_member_int(context->safe_param_ids, param->paramid))
{
@@ -2391,6 +2399,7 @@ convert_saop_to_hashed_saop_walker(Node *node, void *context)
* value of the Param.
* 2. Fold stable, as well as immutable, functions to constants.
* 3. Reduce PlaceHolderVar nodes to their contained expressions.
+ * 4. Current value of session variable can be used for estimation too.
*--------------------
*/
Node *
@@ -2517,6 +2526,27 @@ eval_const_expressions_mutator(Node *node,
}
}
}
+ else if (param->paramkind == PARAM_VARIABLE &&
+ context->estimate)
+ {
+ int16 typLen;
+ bool typByVal;
+ Datum pval;
+ bool isnull;
+
+ get_typlenbyval(param->paramtype,
+ &typLen, &typByVal);
+
+ pval = GetSessionVariable(param->paramvarid, &isnull);
+
+ return (Node *) makeConst(param->paramtype,
+ param->paramtypmod,
+ param->paramcollid,
+ (int) typLen,
+ pval,
+ isnull,
+ typByVal);
+ }
/*
* Not replaceable, so just copy the Param (no need to
@@ -4722,7 +4752,8 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
querytree->limitOffset ||
querytree->limitCount ||
querytree->setOperations ||
- list_length(querytree->targetList) != 1)
+ (list_length(querytree->targetList) != 1) ||
+ querytree->hasSessionVariables)
goto fail;
/* If the function result is composite, resolve it */
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 1f4d6adda52..3df219f98d2 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -25,9 +25,12 @@
#include "postgres.h"
#include "access/sysattr.h"
+#include "catalog/namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
@@ -51,6 +54,7 @@
#include "utils/backend_status.h"
#include "utils/builtins.h"
#include "utils/guc.h"
+#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
@@ -83,6 +87,8 @@ static Query *transformCreateTableAsStmt(ParseState *pstate,
CreateTableAsStmt *stmt);
static Query *transformCallStmt(ParseState *pstate,
CallStmt *stmt);
+static Query *transformLetStmt(ParseState *pstate,
+ LetStmt *stmt);
static void transformLockingClause(ParseState *pstate, Query *qry,
LockingClause *lc, bool pushedDown);
#ifdef DEBUG_NODE_TESTS_ENABLED
@@ -414,6 +420,7 @@ transformStmt(ParseState *pstate, Node *parseTree)
case T_UpdateStmt:
case T_DeleteStmt:
case T_MergeStmt:
+ case T_LetStmt:
(void) test_raw_expression_coverage(parseTree, NULL);
break;
default:
@@ -493,6 +500,11 @@ transformStmt(ParseState *pstate, Node *parseTree)
(CallStmt *) parseTree);
break;
+ case T_LetStmt:
+ result = transformLetStmt(pstate,
+ (LetStmt *) parseTree);
+ break;
+
default:
/*
@@ -545,6 +557,7 @@ stmt_requires_parse_analysis(RawStmt *parseTree)
case T_SelectStmt:
case T_ReturnStmt:
case T_PLAssignStmt:
+ case T_LetStmt:
result = true;
break;
@@ -692,6 +705,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1117,6 +1131,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1582,6 +1597,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, stmt->lockingClause)
{
@@ -1808,12 +1824,241 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
return qry;
}
+/*
+ * transformLetStmt -
+ * transform an Let Statement
+ */
+static Query *
+transformLetStmt(ParseState *pstate, LetStmt *stmt)
+{
+ Query *query;
+ Query *result;
+ List *exprList = NIL;
+ List *exprListCoer = NIL;
+ ListCell *lc;
+ ListCell *indirection_head = NULL;
+ Query *selectQuery;
+ Oid varid;
+ char *attrname = NULL;
+ bool not_unique;
+ bool is_rowtype;
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+ List *names = NULL;
+ int indirection_start;
+ int i = 0;
+
+ /* there can't be any outer WITH to worry about */
+ Assert(pstate->p_ctenamespace == NIL);
+
+ names = NamesFromList(stmt->target);
+
+ /* locks the variable with an AccessShareLock */
+ varid = IdentifyVariable(names, &attrname, ¬_unique, false);
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("target \"%s\" of LET command is ambiguous",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ if (!OidIsValid(varid))
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ /*
+ * Calculate start of possible position of an indirection in list, and
+ * when it is inside the list, store pointer on first node of indirection.
+ */
+ indirection_start = list_length(names) - (attrname ? 1 : 0);
+ if (list_length(stmt->target) > indirection_start)
+ indirection_head = list_nth_cell(stmt->target, indirection_start);
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod, &collid);
+
+ is_rowtype = type_is_rowtype(typid);
+
+ if (attrname && !is_rowtype)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("cannot assign to field \"%s\" of session variable \"%s.%s\" because its type %s is not a composite type",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->location)));
+
+ pstate->p_expr_kind = EXPR_KIND_LET_TARGET;
+
+ /* we need to postpone conversion of "unknown" to text */
+ pstate->p_resolve_unknowns = false;
+
+ selectQuery = transformStmt(pstate, stmt->query);
+
+ /* the grammar should have produced a SELECT */
+ Assert(IsA(selectQuery, Query) && selectQuery->commandType == CMD_SELECT);
+
+ /*
+ * Generate an expression list for the LET that selects all the non-resjunk
+ * columns from the subquery.
+ */
+ exprList = NIL;
+ foreach_node(TargetEntry, tle, selectQuery->targetList)
+ {
+ if (tle->resjunk)
+ continue;
+
+ exprList = lappend(exprList, tle->expr);
+ }
+
+ /* don't allow multicolumn result */
+ if (list_length(exprList) != 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg_plural("assignment expression returned %d column",
+ "assignment expression returned %d columns",
+ list_length(exprList),
+ list_length(exprList)),
+ parser_errposition(pstate,
+ exprLocation((Node *) exprList))));
+
+ exprListCoer = NIL;
+
+ foreach(lc, exprList)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ Expr *coerced_expr;
+ Oid exprtypid;
+
+ /* now we can read the type of the expression */
+ exprtypid = exprType((Node *) expr);
+
+ if (indirection_head)
+ {
+ bool targetIsArray;
+ char *targetName;
+ Param *param;
+
+ targetName = get_session_variable_name(varid);
+ targetIsArray = OidIsValid(get_element_type(typid));
+
+ pstate->p_hasSessionVariables = true;
+
+ param = makeNode(Param);
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+
+ /*
+ * The parameter used as basenode has to have special
+ * mark, because requires special access when we do
+ * SELECT access check.
+ */
+ param->parambasenode = true;
+
+ coerced_expr = (Expr *)
+ transformAssignmentIndirection(pstate,
+ (Node *) param,
+ targetName,
+ targetIsArray,
+ typid,
+ typmod,
+ InvalidOid,
+ stmt->target,
+ indirection_head,
+ (Node *) expr,
+ COERCION_ASSIGNMENT,
+ stmt->location);
+ }
+ else
+ coerced_expr = (Expr *)
+ coerce_to_target_type(pstate,
+ (Node *) expr,
+ exprtypid,
+ typid, typmod,
+ COERCION_ASSIGNMENT,
+ COERCE_IMPLICIT_CAST,
+ stmt->location);
+
+ if (coerced_expr == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("variable \"%s.%s\" is of type %s, but expression is of type %s",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid),
+ format_type_be(exprtypid)),
+ errhint("You will need to rewrite or cast the expression."),
+ parser_errposition(pstate, exprLocation((Node *) expr))));
+
+ exprListCoer = lappend(exprListCoer, coerced_expr);
+ }
+
+ /* generate query's target list using the computed list of expressions */
+ query = makeNode(Query);
+ query->commandType = CMD_SELECT;
+
+ foreach(lc, exprListCoer)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ TargetEntry *tle;
+
+ tle = makeTargetEntry(expr,
+ i + 1,
+ FigureColname((Node *) expr),
+ false);
+ query->targetList = lappend(query->targetList, tle);
+ }
+
+ /* done building the range table and jointree */
+ query->rtable = pstate->p_rtable;
+ query->jointree = makeFromExpr(pstate->p_joinlist, NULL);
+
+ query->hasTargetSRFs = pstate->p_hasTargetSRFs;
+ query->hasSubLinks = pstate->p_hasSubLinks;
+ query->hasSessionVariables = pstate->p_hasSessionVariables;
+
+ /* this is top-level query */
+ query->canSetTag = true;
+
+ /*
+ * Save target session variable ID. It is used later for
+ * acquiring an AccessShareLock on target variable, setting
+ * plan dependency and finally for creating VariableDestReceiver.
+ */
+ query->resultVariable = varid;
+
+ assign_query_collations(pstate, query);
+
+ /*
+ * The query is executed as utility command by nested executor call.
+ * Assigned queryId is required in this case.
+ */
+ if (IsQueryIdEnabled())
+ JumbleQuery(query);
+
+ stmt->query = (Node *) query;
+
+ /* represent the command as a utility Query */
+ result = makeNode(Query);
+ result->commandType = CMD_UTILITY;
+ result->utilityStmt = (Node *) stmt;
+
+ return result;
+}
+
/*
* transformSetOperationStmt -
* transforms a set-operations tree
@@ -2059,6 +2304,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, lockingClause)
{
@@ -2534,6 +2780,7 @@ transformReturnStmt(ParseState *pstate, ReturnStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2601,6 +2848,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2891,9 +3139,15 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
/*
* Transform the target reference. Typically we will get back a Param
* node, but there's no reason to be too picky about its type.
+ *
+ * Session variables should not be used as target of a PL/pgSQL assign
+ * statement. So we should use a dedicated expression kind and disallow
+ * session variables there. The dedicated context allows to eliminate
+ * undesirable warnings about the possibility of a target PL/pgSQL variable
+ * shadowing a session variable.
*/
target = transformExpr(pstate, (Node *) cref,
- EXPR_KIND_UPDATE_TARGET);
+ EXPR_KIND_ASSIGN_TARGET);
targettype = exprType(target);
targettypmod = exprTypmod(target);
targetcollation = exprCollation(target);
@@ -2935,6 +3189,10 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
*/
type_id = exprType((Node *) tle->expr);
+ /*
+ * For indirection processing and additional casts we can use expr_kind
+ * EXPR_KIND_UPDATE_TARGET.
+ */
pstate->p_expr_kind = EXPR_KIND_UPDATE_TARGET;
if (indirection)
@@ -3077,6 +3335,8 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
(LockingClause *) lfirst(l), false);
}
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
+
assign_query_collations(pstate, qry);
/* this must be done after collations, for reliable comparison of exprs */
@@ -3350,6 +3610,16 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt)
true,
stmt->funccall->location);
+ /*
+ * The arguments of CALL statement are evaluated by a direct expression
+ * executor call. This path is unsupported yet, so block it. It will be
+ * enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
assign_expr_collations(pstate, node);
fexpr = castNode(FuncExpr, node);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 2efe42b82a6..9d10f812120 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -297,7 +297,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
DropTransformStmt
DropUserMappingStmt ExplainStmt FetchStmt
GrantStmt GrantRoleStmt ImportForeignSchemaStmt IndexStmt InsertStmt
- ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
+ LetStmt ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
CreateFunctionStmt AlterFunctionStmt ReindexStmt RemoveAggrStmt
RemoveFuncStmt RemoveOperStmt RenameStmt ReturnStmt RevokeStmt RevokeRoleStmt
RuleActionStmt RuleActionStmtOrEmpty RuleStmt
@@ -742,7 +742,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
KEEP KEY KEYS
LABEL LANGUAGE LARGE_P LAST_P LATERAL_P
- LEADING LEAKPROOF LEAST LEFT LEVEL LIKE LIMIT LISTEN LOAD LOCAL
+ LEADING LEAKPROOF LEAST LEFT LET LEVEL LIKE LIMIT LISTEN LOAD LOCAL
LOCALTIME LOCALTIMESTAMP LOCATION LOCK_P LOCKED LOGGED
MAPPING MATCH MATCHED MATERIALIZED MAXVALUE MERGE MERGE_ACTION METHOD
@@ -1089,6 +1089,7 @@ stmt:
| ImportForeignSchemaStmt
| IndexStmt
| InsertStmt
+ | LetStmt
| ListenStmt
| RefreshMatViewStmt
| LoadStmt
@@ -12869,6 +12870,38 @@ opt_hold: /* EMPTY */ { $$ = 0; }
| WITHOUT HOLD { $$ = 0; }
;
+/*****************************************************************************
+ *
+ * QUERY:
+ * LET STATEMENT
+ *
+ *****************************************************************************/
+LetStmt: LET ColId opt_indirection '=' a_expr
+ {
+ LetStmt *n = makeNode(LetStmt);
+ SelectStmt *select;
+ ResTarget *res;
+
+ n->target = lcons(makeString($2),
+ check_indirection($3, yyscanner));
+
+ select = makeNode(SelectStmt);
+ res = makeNode(ResTarget);
+
+ /* create target list for implicit query */
+ res->name = NULL;
+ res->indirection = NIL;
+ res->val = (Node *) $5;
+ res->location = @5;
+
+ select->targetList = list_make1(res);
+ n->query = (Node *) select;
+
+ n->location = @2;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* QUERY:
@@ -17940,6 +17973,7 @@ unreserved_keyword:
| LARGE_P
| LAST_P
| LEAKPROOF
+ | LET
| LEVEL
| LISTEN
| LOAD
@@ -18554,6 +18588,7 @@ bare_label_keyword:
| LEAKPROOF
| LEAST
| LEFT
+ | LET
| LEVEL
| LIKE
| LISTEN
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 0ac8966e30f..de0a4a5653a 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -580,6 +580,11 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
+
/*
* There is intentionally no default: case here, so that the
* compiler will warn if we add a new ParseExprKind without
@@ -970,6 +975,10 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
case EXPR_KIND_CYCLE_MARK:
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 9caf1e481a2..55e4906ad76 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -17,6 +17,7 @@
#include "catalog/pg_aggregate.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
@@ -33,11 +34,13 @@
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "parser/parse_type.h"
+#include "storage/lmgr.h"
#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/timestamp.h"
+#include "utils/typcache.h"
#include "utils/xml.h"
/* GUC parameters */
@@ -106,6 +109,9 @@ static Expr *make_distinct_op(ParseState *pstate, List *opname,
Node *ltree, Node *rtree, int location);
static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
+static Node *makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location);
/*
@@ -499,6 +505,89 @@ transformIndirection(ParseState *pstate, A_Indirection *ind)
return result;
}
+/*
+ * Returns true if the given expression kind is valid for session variables.
+ * Session variables can be used everywhere where external parameters can be
+ * used. Session variables are not allowed in DDL commands or in constraints.
+ *
+ * An identifier can be parsed as a session variable only for expression kinds
+ * where session variables are allowed. This is the primary usage of this
+ * function.
+ *
+ * The second usage of this function is to decide whether a "column does not
+ * exist" or a "column or variable does not exist" error message should be
+ * printed. When we are in an expression where session variables cannot be
+ * used, we raise the first form of error message.
+ */
+static bool
+expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
+{
+ bool result = false;
+
+ switch (p_expr_kind)
+ {
+ case EXPR_KIND_NONE:
+ Assert(false); /* can't happen */
+ return false;
+
+ /* session variables allowed */
+ case EXPR_KIND_OTHER:
+ case EXPR_KIND_JOIN_ON:
+ case EXPR_KIND_FROM_SUBSELECT:
+ case EXPR_KIND_FROM_FUNCTION:
+ case EXPR_KIND_WHERE:
+ case EXPR_KIND_HAVING:
+ case EXPR_KIND_FILTER:
+ case EXPR_KIND_WINDOW_PARTITION:
+ case EXPR_KIND_WINDOW_ORDER:
+ case EXPR_KIND_WINDOW_FRAME_RANGE:
+ case EXPR_KIND_WINDOW_FRAME_ROWS:
+ case EXPR_KIND_WINDOW_FRAME_GROUPS:
+ case EXPR_KIND_SELECT_TARGET:
+ case EXPR_KIND_INSERT_TARGET:
+ case EXPR_KIND_UPDATE_SOURCE:
+ case EXPR_KIND_UPDATE_TARGET:
+ case EXPR_KIND_MERGE_WHEN:
+ case EXPR_KIND_MERGE_RETURNING:
+ case EXPR_KIND_GROUP_BY:
+ case EXPR_KIND_ORDER_BY:
+ case EXPR_KIND_DISTINCT_ON:
+ case EXPR_KIND_LIMIT:
+ case EXPR_KIND_OFFSET:
+ case EXPR_KIND_RETURNING:
+ case EXPR_KIND_VALUES:
+ case EXPR_KIND_VALUES_SINGLE:
+ case EXPR_KIND_ALTER_COL_TRANSFORM:
+ case EXPR_KIND_EXECUTE_PARAMETER:
+ case EXPR_KIND_POLICY:
+ case EXPR_KIND_CALL_ARGUMENT:
+ case EXPR_KIND_COPY_WHERE:
+ case EXPR_KIND_LET_TARGET:
+ result = true;
+ break;
+
+ /* session variables not allowed */
+ case EXPR_KIND_CHECK_CONSTRAINT:
+ case EXPR_KIND_DOMAIN_CHECK:
+ case EXPR_KIND_COLUMN_DEFAULT:
+ case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_INDEX_EXPRESSION:
+ case EXPR_KIND_INDEX_PREDICATE:
+ case EXPR_KIND_STATS_EXPRESSION:
+ case EXPR_KIND_TRIGGER_WHEN:
+ case EXPR_KIND_PARTITION_BOUND:
+ case EXPR_KIND_PARTITION_EXPRESSION:
+ case EXPR_KIND_GENERATED_COLUMN:
+ case EXPR_KIND_JOIN_USING:
+ case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ result = false;
+ break;
+ }
+
+ return result;
+}
+
/*
* Transform a ColumnRef.
*
@@ -575,6 +664,8 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
case EXPR_KIND_COPY_WHERE:
case EXPR_KIND_GENERATED_COLUMN:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
@@ -847,8 +938,61 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
}
/*
- * Throw error if no translation found.
+ * There are contexts where session variables are not allowed. We don't
+ * need to identify session variables in such a context, but identifying
+ * them allows us to raise meaningful error messages like "you cannot use
+ * session variables here".
*/
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind))
+ {
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* -----
+ * Session variables are shadowed by columns, routine variables or
+ * routine arguments. We certainly don't want to use a session variable
+ * when it is exactly shadowed, but a RTE like this is conceivable:
+ *
+ * CREATE TYPE t AS (c int);
+ * CREATE VARIABLE foo AS t;
+ * CREATE TABLE foo(a int, b int);
+ *
+ * SELECT foo.a, foo.b, foo.c FROM foo;
+ *
+ * However, that is very confusing, so we disallow it. We don't try to
+ * identify a variable if we know that it would be shadowed.
+ * -----
+ */
+ if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ {
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(cref->fields)),
+ parser_errposition(pstate, cref->location)));
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ node = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, cref->location);
+ }
+ }
+ }
+
+ /* throw an error if no translation was found */
if (node == NULL)
{
switch (crerr)
@@ -880,6 +1024,75 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
return node;
}
+/*
+ * Generate param variable for reference to session variable
+ */
+static Node *
+makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location)
+{
+ Param *param;
+
+ param = makeNode(Param);
+
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+ param->paramcollid = collid;
+
+ pstate->p_hasSessionVariables = true;
+
+ if (attrname != NULL)
+ {
+ TupleDesc tupdesc;
+ int i;
+
+ tupdesc = lookup_rowtype_tupdesc_noerror(typid, typmod, true);
+ if (!tupdesc)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("variable \"%s.%s\" is of type \"%s\", which is not a composite type",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, location)));
+
+ for (i = 0; i < tupdesc->natts; i++)
+ {
+ Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+ if (strcmp(attrname, NameStr(att->attname)) == 0 &&
+ !att->attisdropped)
+ {
+ /* success, so generate a FieldSelect expression */
+ FieldSelect *fselect = makeNode(FieldSelect);
+
+ fselect->arg = (Expr *) param;
+ fselect->fieldnum = i + 1;
+ fselect->resulttype = att->atttypid;
+ fselect->resulttypmod = att->atttypmod;
+ /* save attribute's collation for parse_collate.c */
+ fselect->resultcollid = att->attcollation;
+
+ ReleaseTupleDesc(tupdesc);
+ return (Node *) fselect;
+ }
+ }
+
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_COLUMN),
+ errmsg("could not identify column \"%s\" in variable \"%s.%s\"",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ parser_errposition(pstate, location)));
+ }
+
+ return (Node *) param;
+}
+
static Node *
transformParamRef(ParseState *pstate, ParamRef *pref)
{
@@ -1815,6 +2028,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_VALUES:
case EXPR_KIND_VALUES_SINGLE:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
case EXPR_KIND_CHECK_CONSTRAINT:
@@ -1858,6 +2072,9 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_GENERATED_COLUMN:
err = _("cannot use subquery in column generation expression");
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ err = _("cannot use subquery as target of assign statement");
+ break;
/*
* There is intentionally no default: case here, so that the
@@ -3215,6 +3432,10 @@ ParseExprKindName(ParseExprKind exprKind)
return "GENERATED AS";
case EXPR_KIND_CYCLE_MARK:
return "CYCLE";
+ case EXPR_KIND_ASSIGN_TARGET:
+ return "ASSIGN";
+ case EXPR_KIND_LET_TARGET:
+ return "LET";
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index 583bbbf232f..dc25f6dcd0e 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2656,6 +2656,8 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location)
err = _("set-returning functions are not allowed in column generation expressions");
break;
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
errkind = true;
break;
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
index 51d7703eff7..244efcddf32 100644
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -405,6 +405,7 @@ transformMergeStmt(ParseState *pstate, MergeStmt *stmt)
qry->hasTargetSRFs = false;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c
index b620766c938..b2f764b657f 100644
--- a/src/backend/tcop/dest.c
+++ b/src/backend/tcop/dest.c
@@ -38,6 +38,7 @@
#include "executor/functions.h"
#include "executor/tqueue.h"
#include "executor/tstoreReceiver.h"
+#include "executor/svariableReceiver.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
@@ -155,6 +156,9 @@ CreateDestReceiver(CommandDest dest)
case DestExplainSerialize:
return CreateExplainSerializeDestReceiver(NULL);
+
+ case DestVariable:
+ return CreateVariableDestReceiver(InvalidOid);
}
/* should never get here */
@@ -191,6 +195,7 @@ EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_o
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -237,6 +242,7 @@ NullCommand(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -281,6 +287,7 @@ ReadyForQuery(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 99a51877d34..7a508a3644f 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -49,6 +49,7 @@
#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
+#include "commands/session_variable.h"
#include "commands/subscriptioncmds.h"
#include "commands/tablecmds.h"
#include "commands/tablespace.h"
@@ -235,6 +236,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CallStmt:
case T_DoStmt:
+ case T_LetStmt:
{
/*
* Commands inside the DO block or the called procedure might
@@ -1067,6 +1069,11 @@ standard_ProcessUtility(PlannedStmt *pstmt,
break;
}
+ case T_LetStmt:
+ ExecuteLetStmt(pstate, (LetStmt *) parsetree, params,
+ queryEnv, qc);
+ break;
+
default:
/* All other statement types have event trigger support */
ProcessUtilitySlow(pstate, pstmt, queryString,
@@ -2206,6 +2213,10 @@ UtilityContainsQuery(Node *parsetree)
return UtilityContainsQuery(qry->utilityStmt);
return qry;
+ case T_LetStmt:
+ qry = castNode(Query, ((LetStmt *) parsetree)->query);
+ return qry;
+
default:
return NULL;
}
@@ -2404,6 +2415,10 @@ CreateCommandTag(Node *parsetree)
tag = CMDTAG_SELECT;
break;
+ case T_LetStmt:
+ tag = CMDTAG_LET;
+ break;
+
/* utility statements --- same whether raw or cooked */
case T_TransactionStmt:
{
@@ -3289,6 +3304,7 @@ GetCommandLogLevel(Node *parsetree)
break;
case T_PLAssignStmt:
+ case T_LetStmt:
lev = LOGSTMT_ALL;
break;
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 9e90acedb91..d6bdae9af7d 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -37,6 +37,7 @@
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablespace.h"
#include "common/keywords.h"
@@ -534,6 +535,7 @@ static char *generate_function_name(Oid funcid, int nargs,
static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2);
static void add_cast_to(StringInfo buf, Oid typid);
static char *generate_qualified_type_name(Oid typid);
+static char *generate_session_variable_name(Oid varid);
static text *string_to_text(char *str);
static char *flatten_reloptions(Oid relid);
static void get_reloptions(StringInfo buf, Datum reloptions);
@@ -8729,6 +8731,14 @@ get_parameter(Param *param, deparse_context *context)
return;
}
+ /* translate paramvarid to session variable name */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ return;
+ }
+
/*
* Alternatively, maybe it's a subplan output, which we print as a
* reference to the subplan. (We could drill down into the subplan and
@@ -13556,6 +13566,42 @@ generate_collation_name(Oid collid)
return result;
}
+/*
+ * generate_session_variable_name
+ * Compute the name to display for a session variable specified by OID
+ *
+ * The result includes all necessary quoting and schema-prefixing.
+ */
+static char *
+generate_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+ char *nspname;
+ char *result;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = NameStr(varform->varname);
+
+ if (!VariableIsVisible(varid))
+ nspname = get_namespace_name_or_temp(varform->varnamespace);
+ else
+ nspname = NULL;
+
+ result = quote_qualified_identifier(nspname, varname);
+
+ ReleaseSysCache(tup);
+
+ return result;
+}
+
/*
* Given a C string, produce a TEXT datum.
*
diff --git a/src/backend/utils/cache/plancache.c b/src/backend/utils/cache/plancache.c
index 3b681647060..886a9240ad5 100644
--- a/src/backend/utils/cache/plancache.c
+++ b/src/backend/utils/cache/plancache.c
@@ -58,6 +58,7 @@
#include "access/transam.h"
#include "catalog/namespace.h"
+#include "catalog/pg_variable.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
@@ -154,6 +155,7 @@ InitPlanCache(void)
CacheRegisterSyscacheCallback(AMOPOPID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNSERVEROID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNDATAWRAPPEROID, PlanCacheSysCallback, (Datum) 0);
+ CacheRegisterSyscacheCallback(VARIABLEOID, PlanCacheObjectCallback, (Datum) 0);
}
/*
@@ -2165,17 +2167,32 @@ ScanQueryForLocks(Query *parsetree, bool acquire)
/*
* Recurse into sublink subqueries, too. But we already did the ones in
- * the rtable and cteList.
+ * the rtable and cteList. We need to force a recursive call for session
+ * variables too, to find and lock variables used in the query (see
+ * ScanQueryWalker).
*/
- if (parsetree->hasSubLinks)
+ if (parsetree->hasSubLinks ||
+ parsetree->hasSessionVariables)
{
query_tree_walker(parsetree, ScanQueryWalker, &acquire,
QTW_IGNORE_RC_SUBQUERIES);
}
+
+ /* process session variables */
+ if (OidIsValid(parsetree->resultVariable))
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ }
}
/*
- * Walker to find sublink subqueries for ScanQueryForLocks
+ * Walker to find sublink subqueries or referenced session variables
+ * for ScanQueryForLocks
*/
static bool
ScanQueryWalker(Node *node, bool *acquire)
@@ -2190,6 +2207,20 @@ ScanQueryWalker(Node *node, bool *acquire)
ScanQueryForLocks(castNode(Query, sub->subselect), *acquire);
/* Fall through to process lefthand args of SubLink */
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ }
+ }
/*
* Do NOT recurse into Query nodes, because ScanQueryForLocks already
@@ -2320,7 +2351,9 @@ PlanCacheRelCallback(Datum arg, Oid relid)
/*
* PlanCacheObjectCallback
- * Syscache inval callback function for PROCOID and TYPEOID caches
+ * Syscache inval callback function for TYPEOID, PROCOID, NAMESPACEOID,
+ * OPEROID, AMOPOPID, FOREIGNSERVEROID, FOREIGNDATAWRAPPEROID and
+ * VARIABLEOID caches.
*
* Invalidate all plans mentioning the object with the specified hash value,
* or all plans mentioning any member of this cache if hashvalue == 0.
diff --git a/src/backend/utils/fmgr/fmgr.c b/src/backend/utils/fmgr/fmgr.c
index 782291d9998..093622fbdc4 100644
--- a/src/backend/utils/fmgr/fmgr.c
+++ b/src/backend/utils/fmgr/fmgr.c
@@ -2026,9 +2026,13 @@ get_call_expr_arg_stable(Node *expr, int argnum)
*/
if (IsA(arg, Const))
return true;
- if (IsA(arg, Param) &&
- ((Param *) arg)->paramkind == PARAM_EXTERN)
- return true;
+ if (IsA(arg, Param))
+ {
+ Param *p = (Param *) arg;
+
+ if (p->paramkind == PARAM_EXTERN || p->paramkind == PARAM_VARIABLE)
+ return true;
+ }
return false;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 94bd86c01b9..78b130c04b0 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1228,8 +1228,8 @@ static const char *const sql_commands[] = {
"ABORT", "ALTER", "ANALYZE", "BEGIN", "CALL", "CHECKPOINT", "CLOSE", "CLUSTER",
"COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE",
"DELETE FROM", "DISCARD", "DO", "DROP", "END", "EXECUTE", "EXPLAIN",
- "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LISTEN", "LOAD", "LOCK",
- "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
+ "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LET",
+ "LISTEN", "LOAD", "LOCK", "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
"REASSIGN", "REFRESH MATERIALIZED VIEW", "REINDEX", "RELEASE",
"RESET", "REVOKE", "ROLLBACK",
"SAVEPOINT", "SECURITY LABEL", "SELECT", "SET", "SHOW", "START",
@@ -4695,6 +4695,14 @@ match_previous_words(int pattern_id,
else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES"))
COMPLETE_WITH("(");
+/* LET */
+ /* If prev. word is LET suggest a list of variables */
+ else if (Matches("LET"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ /* Complete LET <variable> with "=" */
+ else if (TailMatches("LET", MatchAny))
+ COMPLETE_WITH("=");
+
/* LOCK */
/* Complete LOCK [TABLE] [ONLY] with a list of tables */
else if (Matches("LOCK"))
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index bdac0c13bec..5060b8c9490 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -174,6 +174,7 @@ extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
extern List *NamesFromList(List *names);
extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+extern Oid IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror);
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 3d3c6eb24b5..5b45be5afaf 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -18,6 +18,7 @@
#ifndef PG_VARIABLE_H
#define PG_VARIABLE_H
+#include "access/xlogdefs.h"
#include "catalog/genbki.h"
#include "catalog/objectaddress.h"
#include "catalog/pg_variable_d.h"
@@ -35,6 +36,14 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* OID of entry in pg_type for variable's type */
Oid vartype BKI_LOOKUP(pg_type);
+ /*
+ * Used for identity check [oid, create_lsn].
+ *
+ * This column of the 8-byte XlogRecPtr type should be at an address that
+ * is divisible by 8, but before any column of type NameData.
+ */
+ XLogRecPtr varcreate_lsn;
+
/* variable name */
NameData varname;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
new file mode 100644
index 00000000000..2391b9ad443
--- /dev/null
+++ b/src/include/commands/session_variable.h
@@ -0,0 +1,30 @@
+/*-------------------------------------------------------------------------
+ *
+ * sessionvariable.h
+ * prototypes for sessionvariable.c.
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/commands/session_variable.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SESSIONVARIABLE_H
+#define SESSIONVARIABLE_H
+
+#include "nodes/params.h"
+#include "nodes/parsenodes.h"
+#include "parser/parse_node.h"
+#include "tcop/cmdtag.h"
+#include "utils/queryenvironment.h"
+
+extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
+extern Datum GetSessionVariable(Oid varid, bool *isNull);
+
+extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
+ QueryEnvironment *queryEnv, QueryCompletion *qc);
+
+#endif
diff --git a/src/include/executor/svariableReceiver.h b/src/include/executor/svariableReceiver.h
new file mode 100644
index 00000000000..db44d8b94c6
--- /dev/null
+++ b/src/include/executor/svariableReceiver.h
@@ -0,0 +1,22 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.h
+ * prototypes for svariableReceiver.c
+ *
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/executor/svariableReceiver.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SVARIABLE_RECEIVER_H
+#define SVARIABLE_RECEIVER_H
+
+#include "tcop/dest.h"
+
+extern DestReceiver *CreateVariableDestReceiver(Oid varid);
+
+#endif /* SVARIABLE_RECEIVER_H */
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 5b6cadb5a6c..79c0732aad5 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -642,6 +642,16 @@ typedef struct AsyncRequest
* tuples) */
} AsyncRequest;
+/* ----------------
+ * SessionVariableValue
+ * ----------------
+ */
+typedef struct SessionVariableValue
+{
+ bool isnull;
+ Datum value;
+} SessionVariableValue;
+
/* ----------------
* EState information
*
@@ -702,6 +712,10 @@ typedef struct EState
ParamListInfo es_param_list_info; /* values of external params */
ParamExecData *es_param_exec_vals; /* values of internal params */
+ /* Session variables info: */
+ int es_num_session_variables; /* number of used variables */
+ SessionVariableValue *es_session_variables; /* array of copies of values */
+
QueryEnvironment *es_queryEnv; /* query environment */
/* Other working state: */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index ae4b6a3862c..8f874a08d29 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -142,6 +142,9 @@ typedef struct Query
*/
int resultRelation pg_node_attr(query_jumble_ignore);
+ /* target variable of LET statement */
+ Oid resultVariable;
+
/* has aggregates in tlist or havingQual */
bool hasAggs pg_node_attr(query_jumble_ignore);
/* has window functions in tlist */
@@ -162,6 +165,8 @@ typedef struct Query
bool hasRowSecurity pg_node_attr(query_jumble_ignore);
/* parser has added an RTE_GROUP RTE */
bool hasGroupRTE pg_node_attr(query_jumble_ignore);
+ /* uses session variables */
+ bool hasSessionVariables pg_node_attr(query_jumble_ignore);
/* is a RETURN statement */
bool isReturn pg_node_attr(query_jumble_ignore);
@@ -2149,6 +2154,18 @@ typedef struct MergeStmt
ParseLoc stmt_len; /* length in bytes; 0 means "rest of string" */
} MergeStmt;
+/* ----------------------
+ * Let Statement
+ * ----------------------
+ */
+typedef struct LetStmt
+{
+ NodeTag type;
+ List *target; /* target variable */
+ Node *query; /* source expression */
+ ParseLoc location;
+} LetStmt;
+
/* ----------------------
* Select Statement
*
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index 4c466f76778..3f8a4691a36 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -182,6 +182,18 @@ typedef struct PlannerGlobal
/* partition descriptors */
PartitionDirectory partition_directory pg_node_attr(read_write_ignore);
+
+ /* list of used session variables */
+ List *sessionVariables;
+
+ /* Oid of session variable used like target of LET command */
+ Oid resultVariable;
+
+ /* oid of session variable used like base node for assignment indirection */
+ Oid basenodeSessionVarid;
+
+ /* true, if we do SELECT permission check on basenodeSessionVarid */
+ bool basenodeSessionVarSelectCheck;
} PlannerGlobal;
/* macro for fetching the Plan associated with a SubPlan node */
@@ -532,6 +544,8 @@ struct PlannerInfo
bool placeholdersFrozen;
/* true if planning a recursive WITH item */
bool hasRecursion;
+ /* true if session variables were used */
+ bool hasSessionVariables;
/*
* The rangetable index for the RTE_GROUP RTE, or 0 if there is no
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index 658d76225e4..492b9d97e5c 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -138,6 +138,15 @@ typedef struct PlannedStmt
/* non-null if this is utility stmt */
Node *utilityStmt;
+ List *sessionVariables; /* OIDs for PARAM_VARIABLE Params */
+
+ /*
+ * The oid of session variable execluded from permission check.
+ * This session variable is used as base node of assignment indirection
+ * (and it is used only there).
+ */
+ int exclSelectPermCheckVarid;
+
/* statement location in source string (copied from Query) */
/* start location, or -1 if unknown */
ParseLoc stmt_location;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 7d3b4198f26..3cc2f019abb 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -378,6 +378,9 @@ typedef struct Const
* of the `paramid' field contain the SubLink's subLinkId, and
* the low-order 16 bits contain the column number. (This type
* of Param is also converted to PARAM_EXEC during planning.)
+ *
+ * PARAM_VARIABLE: The parameter is a reference to a session variable
+ * (paramvarid holds the variable's OID).
*/
typedef enum ParamKind
{
@@ -385,6 +388,7 @@ typedef enum ParamKind
PARAM_EXEC,
PARAM_SUBLINK,
PARAM_MULTIEXPR,
+ PARAM_VARIABLE,
} ParamKind;
typedef struct Param
@@ -397,6 +401,16 @@ typedef struct Param
int32 paramtypmod pg_node_attr(query_jumble_ignore);
/* OID of collation, or InvalidOid if none */
Oid paramcollid pg_node_attr(query_jumble_ignore);
+ /* OID of session variable if it is used */
+ Oid paramvarid pg_node_attr(query_jumble_ignore);
+
+ /*
+ * true if param is used as base node of assignment indirection
+ * (when target of LET statement is an array field or an record field).
+ * For this param we do not check SELECT access right, because this
+ * param is used just for execution of UPDATE operation.
+ */
+ bool parambasenode;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index 5a930199611..7a3b522b5ff 100644
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -131,4 +131,6 @@ extern void record_plan_function_dependency(PlannerInfo *root, Oid funcid);
extern void record_plan_type_dependency(PlannerInfo *root, Oid typid);
extern bool extract_query_dependencies_walker(Node *node, PlannerInfo *context);
+extern void pull_up_has_session_variables(PlannerInfo *root);
+
#endif /* PLANMAIN_H */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 0ea0265de7c..8c0affba13b 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -257,6 +257,7 @@ PG_KEYWORD("leading", LEADING, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("leakproof", LEAKPROOF, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("least", LEAST, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("left", LEFT, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("let", LET, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("level", LEVEL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("like", LIKE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("limit", LIMIT, RESERVED_KEYWORD, AS_LABEL)
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 994284019fb..0b7b69a4159 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -82,6 +82,8 @@ typedef enum ParseExprKind
EXPR_KIND_COPY_WHERE, /* WHERE condition in COPY FROM */
EXPR_KIND_GENERATED_COLUMN, /* generation expression for a column */
EXPR_KIND_CYCLE_MARK, /* cycle mark value */
+ EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */
+ EXPR_KIND_LET_TARGET, /* LET target */
} ParseExprKind;
@@ -244,6 +246,7 @@ struct ParseState
bool p_hasTargetSRFs;
bool p_hasSubLinks;
bool p_hasModifyingCTE;
+ bool p_hasSessionVariables;
Node *p_last_srf; /* most recent set-returning func/op found */
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index ea86954dded..22082c30008 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -186,6 +186,7 @@ PG_CMDTAG(CMDTAG_GRANT, "GRANT", true, false, false)
PG_CMDTAG(CMDTAG_GRANT_ROLE, "GRANT ROLE", false, false, false)
PG_CMDTAG(CMDTAG_IMPORT_FOREIGN_SCHEMA, "IMPORT FOREIGN SCHEMA", true, false, false)
PG_CMDTAG(CMDTAG_INSERT, "INSERT", false, false, true)
+PG_CMDTAG(CMDTAG_LET, "LET", false, false, false)
PG_CMDTAG(CMDTAG_LISTEN, "LISTEN", false, false, false)
PG_CMDTAG(CMDTAG_LOAD, "LOAD", false, false, false)
PG_CMDTAG(CMDTAG_LOCK_TABLE, "LOCK TABLE", false, false, false)
diff --git a/src/include/tcop/dest.h b/src/include/tcop/dest.h
index 00c092e3d7c..6ce3ea0e617 100644
--- a/src/include/tcop/dest.h
+++ b/src/include/tcop/dest.h
@@ -97,6 +97,7 @@ typedef enum
DestTransientRel, /* results sent to transient relation */
DestTupleQueue, /* results sent to tuple queue */
DestExplainSerialize, /* results are serialized and discarded */
+ DestVariable, /* results sent to session variable */
} CommandDest;
/* ----------------
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index bb99781c56e..1cff5efa6f7 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8264,7 +8264,8 @@ exec_is_simple_query(PLpgSQL_expr *expr)
query->sortClause ||
query->limitOffset ||
query->limitCount ||
- query->setOperations)
+ query->setOperations ||
+ query->hasSessionVariables)
return false;
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index c36660ce6d3..f22467186e3 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -431,3 +431,1235 @@ DROP VARIABLE public.var1;
DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+-- check access rights
+CREATE ROLE regress_noowner;
+CREATE VARIABLE var1 AS int;
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+-- should fail
+SET ROLE TO regress_noowner;
+SELECT var1;
+ERROR: permission denied for session variable var1
+SELECT sqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: SQL function "sqlfx" statement 1
+SELECT plpgsqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "$1 + var1"
+PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
+-- should be ok
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+-- should be ok
+SET ROLE TO regress_noowner;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+DROP ROLE regress_noowner;
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- start a new session
+\c
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- should fail, dependency
+DROP VARIABLE var1;
+ERROR: cannot drop session variable var1 because other objects depend on it
+DETAIL: view test_view depends on session variable var1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+NOTICE: drop cascades to view test_view
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+LET var1 = 'str1';
+LET var2 = 'str2';
+SELECT sqlfx1(sqlfx2('Hello'));
+ sqlfx1
+-------------------
+ str1, str2, Hello
+(1 row)
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+ QUERY PLAN
+------------------------------------------------------
+ Result
+ Output: sqlfx1(sqlfx2('Hello'::character varying))
+(2 rows)
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+SET plan_cache_mode TO force_generic_plan;
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 3.14
+(1 row)
+
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 6.28
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 9.42
+(1 row)
+
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 12.56
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+ERROR: function plpgsqlfx2() does not exist
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+SET plan_cache_mode TO DEFAULT;
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 1
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 55
+DROP VARIABLE var1;
+DROP TABLE testvar;
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+NOTICE: result array: {1,2,3,4,5,6,7,8,9,10}
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+-- should not crash (but is not supported yet)
+CALL p(v);
+ERROR: session variable cannot be used as an argument
+DO $$ BEGIN CALL p(v); END $$;
+ERROR: session variable cannot be used as an argument
+CONTEXT: SQL statement "CALL p(v)"
+PL/pgSQL function inline_code_block line 1 at CALL
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+-- should fail
+EXECUTE ptest(v);
+ERROR: session variable cannot be used as an argument
+DEALLOCATE ptest;
+DROP VARIABLE v;
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+-- should fail
+LET var1 = pi();
+ERROR: session variable "var1" doesn't exist
+LINE 1: LET var1 = pi();
+ ^
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+ var1
+------------------
+ 3.14159265358979
+(1 row)
+
+SET search_path TO svartest;
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+ var1
+------------------
+ 13.1415926535898
+(1 row)
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to session variable svartest.var1
+CREATE VARIABLE var1 AS text;
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+SELECT var1;
+ var1
+-------
+ hello
+(1 row)
+
+DROP VARIABLE var1;
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+-- should fail
+SELECT var1;
+ERROR: domain int_domain does not allow null values
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+ var1
+------
+ 1000
+(1 row)
+
+-- should fail
+LET var1 = 10;
+ERROR: value for domain int_domain violates check constraint "int_domain_check"
+-- should fail
+LET var1 = NULL;
+ERROR: domain int_domain does not allow null values
+-- note - domain defaults are not supported yet (like PLpgSQL)
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+ var1
+----------------------------------------
+ {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+(1 row)
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+DROP VARIABLE var1;
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+ var1
+------
+ 100
+(1 row)
+
+SET search_path to public, svartest;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table foo
+drop cascades to session variable var1
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+LET var2[var1] = 0;
+SELECT var2;
+ var2
+-----------
+ [2:2]={0}
+(1 row)
+
+DROP VARIABLE var1, var2;
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+SELECT var2;
+ var2
+------
+ {}
+(1 row)
+
+DROP VARIABLE var1, var2;
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+ERROR: syntax error at or near "LET"
+LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x;
+ ^
+-- should be ok
+LET var1 = generate_series(1, 1);
+-- should fail
+LET var1 = generate_series(1, 2);
+ERROR: expression returned more than one row
+LET var1 = generate_series(1, 0);
+ERROR: expression returned no rows
+DROP VARIABLE var1;
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+SELECT v1;
+ v1
+------------
+ (1,2,3.00)
+(1 row)
+
+SELECT v2;
+ v2
+---------------
+ (10,20,31.40)
+(1 row)
+
+SELECT (v1).*;
+ x | y | z
+---+---+------
+ 1 | 2 | 3.00
+(1 row)
+
+SELECT (v2).*;
+ x | y | z
+----+----+-------
+ 10 | 20 | 31.40
+(1 row)
+
+SELECT v1.x + v1.z;
+ ?column?
+----------
+ 4.00
+(1 row)
+
+SELECT v2.x + v2.z;
+ ?column?
+----------
+ 41.40
+(1 row)
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail
+SELECT v2.x;
+ERROR: permission denied for session variable v2
+SET ROLE TO DEFAULT;
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+ERROR: improper qualified name (too many dotted names): nodb.noschema.novar.nofield.nosubfield
+LET nodb.noschema.novar.nofield = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar.nofield
+LET nodb.noschema.novar = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar
+CREATE TYPE t1 AS (a int, b numeric, c text);
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+ v1
+----------------------------
+ (1,3.14159265358979,hello)
+(1 row)
+
+LET v1.b = 10.2222;
+SELECT v1;
+ v1
+-------------------
+ (1,10.2222,hello)
+(1 row)
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1
+LINE 1: LET v1.x = 10;
+ ^
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+ERROR: assignment expression returned 3 columns
+LINE 1: LET v1 = (NULL::t1).*;
+ ^
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+ v1
+-------------
+ (1,10.2222)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+ v1
+--------------
+ (1,10.2222,)
+(1 row)
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+ v1
+--------------
+ (10,10.3,20)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+ v1
+---------
+ (10,20)
+(1 row)
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+ERROR: cannot alter type "t1" because session variable "public.v1" uses it
+DROP VARIABLE v1;
+DROP TYPE t1;
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+ var1
+----------------------------------
+ (10,3.14159265358979,05-26-2023)
+(1 row)
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+ERROR: cannot alter table "svar_test" because session variable "public.var1" uses it
+-- should fail
+DROP TABLE svar_test;
+ERROR: cannot drop table svar_test because other objects depend on it
+DETAIL: session variable var1 depends on type svar_test
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+CREATE ROLE regress_var_test_role;
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+-- should fail
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+SELECT var1.a;
+ a
+------
+ 1000
+(1 row)
+
+SELECT var1;
+ var1
+------------
+ (1000,100)
+(1 row)
+
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+NOTICE: (0,100)
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+NOTICE: 0
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail again
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+-- should fail
+SELECT var1.a;
+ERROR: variable "public.var1" is of type "text", which is not a composite type
+LINE 1: SELECT var1.a;
+ ^
+SELECT var2.c;
+ERROR: could not identify column "c" in variable "public.var2"
+LINE 1: SELECT var2.c;
+ ^
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+-- should fail
+LET var1 = '1'::jsonb;
+ERROR: variable "public.var1" is of type integer, but expression is of type jsonb
+LINE 1: LET var1 = '1'::jsonb;
+ ^
+HINT: You will need to rewrite or cast the expression.
+-- should be ok
+LET var1 = '1'::jsonb::int;
+-- should fail
+LET var1.x = 10;
+ERROR: cannot assign to field "x" of session variable "public.var1" because its type integer is not a composite type
+LINE 1: LET var1.x = 10;
+ ^
+DROP VARIABLE var1;
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+-- should fail
+LET vartest.vartest = 1;
+ERROR: target "vartest.vartest" of LET command is ambiguous
+LINE 1: LET vartest.vartest = 1;
+ ^
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+ERROR: type "vartesttype" does not exist
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+ var1
+------------
+ {10.1,2.1}
+(1 row)
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+ERROR: set-returning functions are not allowed in LET
+LINE 1: LET var1[generate_series(1,3)] = 100;
+ ^
+DROP VARIABLE var1;
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+ var1
+--------------------
+ (10.2,"{0.0,0.0}")
+(1 row)
+
+LET var1.b[1] = 10.3;
+SELECT var1;
+ var1
+---------------------
+ (10.2,"{10.3,0.0}")
+(1 row)
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ count
+-------
+ 100
+(1 row)
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ QUERY PLAN
+-----------------------------------
+ Aggregate
+ -> Seq Scan on svar_test
+ Filter: ((a % 10) = zero)
+(3 rows)
+
+LET zero = (SELECT count(*) FROM svar_test);
+-- result should be 1000
+SELECT zero;
+ zero
+------
+ 1000
+(1 row)
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO on;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO off;
+DROP VIEW var1view;
+DROP VARIABLE var1;
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 100
+(1 row)
+
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 200
+(1 row)
+
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+---
+(0 rows)
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+ relname
+----------
+ pg_class
+(1 row)
+
+DROP VARIABLE var1;
+CREATE TABLE xxtab(avar int);
+INSERT INTO xxtab VALUES(333);
+CREATE TYPE xxtype AS (avar int);
+CREATE VARIABLE xxtab AS xxtype;
+INSERT INTO xxtab VALUES(10);
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+CREATE VARIABLE public.avar AS int;
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+ avar
+------
+
+
+(2 rows)
+
+DROP VARIABLE xxtab;
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+DROP VARIABLE public.avar;
+DROP TYPE xxtype;
+DROP TABLE xxtab;
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+CREATE TABLE public.svar(a int, b int);
+INSERT INTO public.svar VALUES(10, 20);
+LET public.svar = (100, 200, 300);
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT var1.* FROM vartest_foo;
+ ^
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+ a | b
+----+----
+ 10 | 20
+ 30 | 40
+(2 rows)
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT count(var1.*) FROM vartest_foo;
+ ^
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+ count
+-------
+ 2
+(1 row)
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table vartest.vartest_foo
+drop cascades to session variable vartest.var1
+CREATE TYPE ab AS (a integer, b integer);
+CREATE VARIABLE v_ab AS ab;
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+CREATE SCHEMA v_ab;
+CREATE VARIABLE v_ab.a AS integer;
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+SET search_path TO public;
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+-- should be ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+-- should be still ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+ERROR: session variable reference "xxx_am.b" is ambiguous
+LINE 1: SELECT xxx_am.b;
+ ^
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+ b
+----
+ 10
+(1 row)
+
+SELECT :"DBNAME".xxx_am.b;
+ b
+----
+ 20
+(1 row)
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+ b
+----
+ 10
+(1 row)
+
+SELECT x.b FROM xxx_am x;
+ b
+----
+ 10
+(1 row)
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+CREATE SCHEMA :"DBNAME";
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+SET search_path TO :"DBNAME";
+-- should be ambiguous
+SELECT :"DBNAME".b;
+ERROR: session variable reference "regression.b" is ambiguous
+LINE 1: SELECT "regression".b;
+ ^
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+ERROR: session variable reference "regression.regression.b" is ambiguous
+LINE 1: SELECT "regression"."regression".b;
+ ^
+CREATE TABLE :"DBNAME"(b int);
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+ b
+---
+(0 rows)
+
+DROP TABLE :"DBNAME";
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+RESET search_path;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index eeb0f94ca3c..e72360d5254 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -295,3 +295,886 @@ DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+
+-- check access rights
+CREATE ROLE regress_noowner;
+
+CREATE VARIABLE var1 AS int;
+
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+SELECT sqlfx(20);
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx(20);
+SELECT plpgsqlfx_sd(20);
+
+-- should fail
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+-- should be ok
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx_sd(20);
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+
+-- should be ok
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+
+DROP ROLE regress_noowner;
+
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- start a new session
+\c
+
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- should fail, dependency
+DROP VARIABLE var1;
+
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+
+LET var1 = 'str1';
+LET var2 = 'str2';
+
+SELECT sqlfx1(sqlfx2('Hello'));
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+
+SET plan_cache_mode TO force_generic_plan;
+
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+
+SET plan_cache_mode TO DEFAULT;
+
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP TABLE testvar;
+
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+
+-- should not crash (but is not supported yet)
+CALL p(v);
+
+DO $$ BEGIN CALL p(v); END $$;
+
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+
+-- should fail
+EXECUTE ptest(v);
+
+DEALLOCATE ptest;
+DROP VARIABLE v;
+
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+
+-- should fail
+LET var1 = pi();
+SELECT var1;
+
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+
+SET search_path TO svartest;
+
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS text;
+
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+
+-- should fail
+SELECT var1;
+
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+
+-- should fail
+LET var1 = 10;
+
+-- should fail
+LET var1 = NULL;
+
+-- note - domain defaults are not supported yet (like PLpgSQL)
+
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+
+SET search_path to public, svartest;
+
+SELECT var1;
+
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+LET var2[var1] = 0;
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+
+-- should be ok
+LET var1 = generate_series(1, 1);
+
+-- should fail
+LET var1 = generate_series(1, 2);
+LET var1 = generate_series(1, 0);
+
+DROP VARIABLE var1;
+
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+
+SELECT v1;
+SELECT v2;
+SELECT (v1).*;
+SELECT (v2).*;
+
+SELECT v1.x + v1.z;
+SELECT v2.x + v2.z;
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should fail
+SELECT v2.x;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+LET nodb.noschema.novar.nofield = 10;
+LET nodb.noschema.novar = 10;
+
+CREATE TYPE t1 AS (a int, b numeric, c text);
+
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+LET v1.b = 10.2222;
+SELECT v1;
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+
+DROP VARIABLE v1;
+DROP TYPE t1;
+
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+
+-- should fail
+DROP TABLE svar_test;
+
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+
+CREATE ROLE regress_var_test_role;
+
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+
+-- should fail
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should fail again
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+
+-- should fail
+SELECT var1.a;
+SELECT var2.c;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+
+CREATE VARIABLE var1 AS int;
+
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+
+-- should fail
+LET var1 = '1'::jsonb;
+
+-- should be ok
+LET var1 = '1'::jsonb::int;
+
+-- should fail
+LET var1.x = 10;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+
+-- should fail
+LET vartest.vartest = 1;
+
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+
+DROP VARIABLE var1;
+
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+LET var1.b[1] = 10.3;
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+LET zero = (SELECT count(*) FROM svar_test);
+
+-- result should be 1000
+SELECT zero;
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO on;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO off;
+
+DROP VIEW var1view;
+DROP VARIABLE var1;
+
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+
+DROP VARIABLE var1;
+
+CREATE TABLE xxtab(avar int);
+
+INSERT INTO xxtab VALUES(333);
+
+CREATE TYPE xxtype AS (avar int);
+
+CREATE VARIABLE xxtab AS xxtype;
+
+INSERT INTO xxtab VALUES(10);
+
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+
+-- should be ok
+SELECT avar FROM xxtab;
+
+CREATE VARIABLE public.avar AS int;
+
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+
+DROP VARIABLE xxtab;
+
+SELECT xxtab.avar FROM xxtab;
+
+DROP VARIABLE public.avar;
+
+DROP TYPE xxtype;
+
+DROP TABLE xxtab;
+
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+
+CREATE TABLE public.svar(a int, b int);
+
+INSERT INTO public.svar VALUES(10, 20);
+
+LET public.svar = (100, 200, 300);
+
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+
+CREATE TYPE ab AS (a integer, b integer);
+
+CREATE VARIABLE v_ab AS ab;
+
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+CREATE SCHEMA v_ab;
+
+CREATE VARIABLE v_ab.a AS integer;
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+
+SET search_path TO public;
+
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+
+-- should be ok
+SELECT xxx_am;
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+
+-- should be still ok
+SELECT xxx_am;
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+SELECT :"DBNAME".xxx_am.b;
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+SELECT x.b FROM xxx_am x;
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+
+CREATE SCHEMA :"DBNAME";
+
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+
+SET search_path TO :"DBNAME";
+
+-- should be ambiguous
+SELECT :"DBNAME".b;
+
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+
+CREATE TABLE :"DBNAME"(b int);
+
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+
+DROP TABLE :"DBNAME";
+
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+
+RESET search_path;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index f18ace1be15..5a3727a6cce 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1536,6 +1536,7 @@ LargeObjectDesc
Latch
LauncherLastStartTimesEntry
LerpFunc
+LetStmt
LexDescr
LexemeEntry
LexemeHashKey
@@ -2688,6 +2689,7 @@ SerializedTransactionState
Session
SessionBackupState
SessionEndType
+SessionVariableValue
SetConstraintState
SetConstraintStateData
SetConstraintTriggerData
@@ -2888,6 +2890,9 @@ SupportRequestRows
SupportRequestSelectivity
SupportRequestSimplify
SupportRequestWFuncMonotonic
+SVariable
+SVariableData
+SVariableState
Syn
SyncOps
SyncRepConfigData
--
2.49.0
[text/x-patch] v20250405-0001-Enhancing-catalog-for-support-session-variables-and-.patch (169.5K, ../../CAFj8pRAx-Gb9Ux825cxGNm38qQUOrij1GY6erPRaQ=cpqfiX7g@mail.gmail.com/10-v20250405-0001-Enhancing-catalog-for-support-session-variables-and-.patch)
download | inline diff:
From 175b9df184c4f7f545d13b3e866ecc929f11c1df Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 15:41:55 +0100
Subject: [PATCH 01/21] Enhancing catalog for support session variables and
related support
This patch introduces new system catalog table pg_variable. This table holds metadata about
session variables created by command CREATE VARIABLE, and dropped by command DROP VARIABLE.
Both commands are implemented by this patch. Possibility to change owner, schema or rename.
Access to session variables can be controlled by SELECT or UPDATE rights. Both rights are
introduced by this patch too.
This patch enhancing pg_dump and psql to support session variables. The changes are related
to system catalog.
This patch is not short, but the code is simple.
---
doc/src/sgml/catalogs.sgml | 121 +++++
doc/src/sgml/ddl.sgml | 40 +-
doc/src/sgml/func.sgml | 32 ++
doc/src/sgml/glossary.sgml | 15 +
doc/src/sgml/ref/allfiles.sgml | 3 +
.../sgml/ref/alter_default_privileges.sgml | 29 +-
doc/src/sgml/ref/alter_variable.sgml | 178 +++++++
doc/src/sgml/ref/comment.sgml | 1 +
doc/src/sgml/ref/create_schema.sgml | 12 +-
doc/src/sgml/ref/create_variable.sgml | 149 ++++++
doc/src/sgml/ref/drop_variable.sgml | 117 +++++
doc/src/sgml/ref/grant.sgml | 20 +-
doc/src/sgml/ref/psql-ref.sgml | 13 +
doc/src/sgml/ref/revoke.sgml | 8 +
doc/src/sgml/reference.sgml | 3 +
src/backend/catalog/Makefile | 1 +
src/backend/catalog/aclchk.c | 76 +++
src/backend/catalog/dependency.c | 6 +
src/backend/catalog/meson.build | 1 +
src/backend/catalog/namespace.c | 221 +++++++++
src/backend/catalog/objectaddress.c | 121 ++++-
src/backend/catalog/pg_shdepend.c | 2 +
src/backend/catalog/pg_variable.c | 251 ++++++++++
src/backend/commands/alter.c | 9 +
src/backend/commands/dropcmds.c | 4 +
src/backend/commands/event_trigger.c | 4 +
src/backend/commands/seclabel.c | 1 +
src/backend/commands/tablecmds.c | 41 ++
src/backend/commands/typecmds.c | 15 +
src/backend/parser/gram.y | 105 ++++-
src/backend/parser/parse_utilcmd.c | 12 +
src/backend/tcop/utility.c | 20 +
src/backend/utils/adt/acl.c | 221 +++++++++
src/backend/utils/cache/lsyscache.c | 113 +++++
src/bin/pg_dump/common.c | 3 +
src/bin/pg_dump/dumputils.c | 6 +
src/bin/pg_dump/pg_backup.h | 2 +
src/bin/pg_dump/pg_backup_archiver.c | 9 +
src/bin/pg_dump/pg_dump.c | 190 ++++++++
src/bin/pg_dump/pg_dump.h | 15 +
src/bin/pg_dump/pg_dump_sort.c | 7 +
src/bin/pg_dump/t/002_pg_dump.pl | 64 +++
src/bin/psql/command.c | 3 +
src/bin/psql/describe.c | 100 +++-
src/bin/psql/describe.h | 3 +
src/bin/psql/help.c | 1 +
src/bin/psql/tab-complete.in.c | 45 +-
src/include/catalog/Makefile | 3 +-
src/include/catalog/meson.build | 1 +
src/include/catalog/namespace.h | 6 +
src/include/catalog/pg_default_acl.h | 1 +
src/include/catalog/pg_proc.dat | 23 +
src/include/catalog/pg_variable.h | 81 ++++
src/include/nodes/parsenodes.h | 16 +
src/include/parser/kwlist.h | 2 +
src/include/tcop/cmdtaglist.h | 3 +
src/include/utils/acl.h | 1 +
src/include/utils/lsyscache.h | 9 +
src/test/regress/expected/dependency.out | 17 +
src/test/regress/expected/oidjoins.out | 4 +
src/test/regress/expected/psql.out | 50 ++
.../regress/expected/session_variables.out | 433 ++++++++++++++++++
src/test/regress/parallel_schedule | 2 +-
src/test/regress/sql/dependency.sql | 14 +
src/test/regress/sql/psql.sql | 21 +
src/test/regress/sql/session_variables.sql | 297 ++++++++++++
src/tools/pgindent/typedefs.list | 4 +
67 files changed, 3366 insertions(+), 35 deletions(-)
create mode 100644 doc/src/sgml/ref/alter_variable.sgml
create mode 100644 doc/src/sgml/ref/create_variable.sgml
create mode 100644 doc/src/sgml/ref/drop_variable.sgml
create mode 100644 src/backend/catalog/pg_variable.c
create mode 100644 src/include/catalog/pg_variable.h
create mode 100644 src/test/regress/expected/session_variables.out
create mode 100644 src/test/regress/sql/session_variables.sql
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 45ba9c5118f..2bc8de3e28b 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -369,6 +369,11 @@
<entry><link linkend="catalog-pg-user-mapping"><structname>pg_user_mapping</structname></link></entry>
<entry>mappings of users to foreign servers</entry>
</row>
+
+ <row>
+ <entry><link linkend="catalog-pg-variable"><structname>pg_variable</structname></link></entry>
+ <entry>session variables</entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -3362,6 +3367,7 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
<literal>T</literal> = type,
<literal>n</literal> = schema,
<literal>L</literal> = large object
+ <literal>V</literal> = session variable
</para></entry>
</row>
@@ -9779,4 +9785,119 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</table>
</sect1>
+ <sect1 id="catalog-pg-variable">
+ <title><structname>pg_variable</structname></title>
+
+ <indexterm zone="catalog-pg-variable">
+ <primary>pg_variable</primary>
+ </indexterm>
+
+ <para>
+ The catalog <structname>pg_variable</structname> stores information about
+ session variables.
+ </para>
+
+ <table>
+ <title><structname>pg_variable</structname> Columns</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ Column Type
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>oid</structfield> <type>oid</type>
+ </para>
+ <para>
+ Row identifier
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartype</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-type"><structname>pg_type</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the variable's data type
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varname</structfield> <type>name</type>
+ </para>
+ <para>
+ Name of the session variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varnamespace</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the namespace that contains this variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varowner</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ Owner of the variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartypmod</structfield> <type>int4</type>
+ </para>
+ <para>
+ <structfield>vartypmod</structfield> records type-specific data
+ supplied at variable creation time (for example, the maximum
+ length of a <type>varchar</type> column). It is passed to
+ type-specific input functions and length coercion functions.
+ The value will generally be -1 for types that do not need <structfield>vartypmod</structfield>.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcollation</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-collation"><structname>pg_collation</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The defined collation of the variable, or zero if the variable is
+ not of a collatable data type.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varacl</structfield> <type>aclitem[]</type>
+ </para>
+ <para>
+ Access privileges; see
+ <xref linkend="sql-grant"/> and
+ <xref linkend="sql-revoke"/>
+ for details
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+ </sect1>
</chapter>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index d2082b7e88e..6a493c2f561 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -2018,6 +2018,7 @@ REVOKE ALL ON accounts FROM PUBLIC;
For sequences, this privilege also allows use of the
<function>currval</function> function.
For large objects, this privilege allows the object to be read.
+ For session variables, this privilege allows the object to be read.
</para>
</listitem>
</varlistentry>
@@ -2053,6 +2054,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<function>setval</function> functions.
For large objects, this privilege allows writing or truncating the
object.
+ For session variables, this privilege allows to set a value to the
+ object.
</para>
</listitem>
</varlistentry>
@@ -2296,7 +2299,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal> (and table-like objects),
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2311,7 +2315,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal>,
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2498,6 +2503,12 @@ REVOKE ALL ON accounts FROM PUBLIC;
<entry><literal>U</literal></entry>
<entry><literal>\dT+</literal></entry>
</row>
+ <row>
+ <entry><literal>SESSION VARIABLE</literal></entry>
+ <entry><literal>rw</literal></entry>
+ <entry><literal>none</literal></entry>
+ <entry><literal>\dV+</literal></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -5354,6 +5365,31 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
</para>
</sect1>
+ <sect1 id="ddl-session-variables">
+ <title>Session Variables</title>
+
+ <indexterm zone="ddl-session-variables">
+ <primary>Session variables</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ </indexterm>
+
+ <para>
+ Session variables are database objects that can hold a value.
+ Session variables, like relations, exist within a schema and their access
+ is controlled via <command>GRANT</command> and <command>REVOKE</command>
+ commands. A session variable can be created by the <command>CREATE
+ VARIABLE</command> command.
+ </para>
+
+ <para>
+ The session variable holds value in session memory. This value is private
+ to each session and is released when the session ends.
+ </para>
+ </sect1>
+
<sect1 id="ddl-others">
<title>Other Database Objects</title>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 0224f93733d..988a772e82d 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25589,6 +25589,25 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
</para></entry>
</row>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>has_session_variable_privilege</primary>
+ </indexterm>
+ <function>has_session_variable_privilege</function> (
+ <optional> <parameter>user</parameter> <type>name</type> or <type>oid</type>, </optional>
+ <parameter>session_variable</parameter> <type>text</type> or <type>oid</type>,
+ <parameter>privilege</parameter> <type>text</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Does user have privilege for session variable?
+ Allowable privilege types are
+ <literal>SELECT</literal>, and
+ <literal>UPDATE</literal>.
+ </para></entry>
+ </row>
+
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
@@ -26097,6 +26116,19 @@ SELECT relname FROM pg_class WHERE pg_table_is_visible(oid);
Is type (or domain) visible in search path?
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_variable_is_visible</primary>
+ </indexterm>
+ <function>pg_variable_is_visible</function> ( <parameter>variable</parameter> <type>oid</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Is session variable visible in search path?
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index b88cac598e9..83b13f98f28 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1708,6 +1708,21 @@
</glossdef>
</glossentry>
+ <glossentry id="glossary-session-variable">
+ <glossterm>Session variable</glossterm>
+ <glossdef>
+ <para>
+ A persistent database object that holds a value in session memory. This
+ value is private to each session and is released when the session ends.
+ Read or write access to session variables is controlled by privileges,
+ similar to other database objects.
+ </para>
+ <para>
+ For more information, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </glossdef>
+ </glossentry>
+
<glossentry id="glossary-shared-memory">
<glossterm>Shared memory</glossterm>
<glossdef>
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index f5be638867a..2f67de3e21b 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -47,6 +47,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY alterType SYSTEM "alter_type.sgml">
<!ENTITY alterUser SYSTEM "alter_user.sgml">
<!ENTITY alterUserMapping SYSTEM "alter_user_mapping.sgml">
+<!ENTITY alterVariable SYSTEM "alter_variable.sgml">
<!ENTITY alterView SYSTEM "alter_view.sgml">
<!ENTITY analyze SYSTEM "analyze.sgml">
<!ENTITY begin SYSTEM "begin.sgml">
@@ -99,6 +100,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY createType SYSTEM "create_type.sgml">
<!ENTITY createUser SYSTEM "create_user.sgml">
<!ENTITY createUserMapping SYSTEM "create_user_mapping.sgml">
+<!ENTITY createVariable SYSTEM "create_variable.sgml">
<!ENTITY createView SYSTEM "create_view.sgml">
<!ENTITY deallocate SYSTEM "deallocate.sgml">
<!ENTITY declare SYSTEM "declare.sgml">
@@ -147,6 +149,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY dropType SYSTEM "drop_type.sgml">
<!ENTITY dropUser SYSTEM "drop_user.sgml">
<!ENTITY dropUserMapping SYSTEM "drop_user_mapping.sgml">
+<!ENTITY dropVariable SYSTEM "drop_variable.sgml">
<!ENTITY dropView SYSTEM "drop_view.sgml">
<!ENTITY end SYSTEM "end.sgml">
<!ENTITY execute SYSTEM "execute.sgml">
diff --git a/doc/src/sgml/ref/alter_default_privileges.sgml b/doc/src/sgml/ref/alter_default_privileges.sgml
index 6acd0f1df91..bc73817061f 100644
--- a/doc/src/sgml/ref/alter_default_privileges.sgml
+++ b/doc/src/sgml/ref/alter_default_privileges.sgml
@@ -56,6 +56,11 @@ GRANT { { SELECT | UPDATE }
ON LARGE OBJECTS
TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+GRANT { { SELECT | UPDATE }
+ [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+
REVOKE [ GRANT OPTION FOR ]
{ { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER | MAINTAIN }
[, ...] | ALL [ PRIVILEGES ] }
@@ -95,6 +100,14 @@ REVOKE [ GRANT OPTION FOR ]
ON LARGE OBJECTS
FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
[ CASCADE | RESTRICT ]
+
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE }
+ [, ...] | ALL [ PRIVILEGES ] }
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
+ [ CASCADE | RESTRICT ]
</synopsis>
</refsynopsisdiv>
@@ -129,14 +142,14 @@ REVOKE [ GRANT OPTION FOR ]
<para>
Currently,
only the privileges for schemas, tables (including views and foreign
- tables), sequences, functions, types (including domains), and large objects
- can be altered. For this command, functions include aggregates and procedures.
- The words <literal>FUNCTIONS</literal> and <literal>ROUTINES</literal> are
- equivalent in this command. (<literal>ROUTINES</literal> is preferred
- going forward as the standard term for functions and procedures taken
- together. In earlier PostgreSQL releases, only the
- word <literal>FUNCTIONS</literal> was allowed. It is not possible to set
- default privileges for functions and procedures separately.)
+ tables), sequences, functions, types (including domains), large objects
+ and session variables can be altered. For this command, functions include
+ aggregates and procedures. The words <literal>FUNCTIONS</literal> and
+ <literal>ROUTINES</literal> are equivalent in this command.
+ (<literal>ROUTINES</literal> is preferred going forward as the standard term
+ for functions and procedures taken together. In earlier PostgreSQL releases,
+ only the word <literal>FUNCTIONS</literal> was allowed. It is not possible
+ to set default privileges for functions and procedures separately.)
</para>
<para>
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
new file mode 100644
index 00000000000..96d2586423e
--- /dev/null
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -0,0 +1,178 @@
+<!--
+doc/src/sgml/ref/alter_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-altervariable">
+ <indexterm zone="sql-altervariable">
+ <primary>ALTER VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>altering</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>ALTER VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>ALTER VARIABLE</refname>
+ <refpurpose>
+ change the definition of a session variable
+ </refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable class="parameter">new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable class="parameter">new_name</replaceable>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> SET SCHEMA <replaceable class="parameter">new_schema</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>ALTER VARIABLE</command> command changes the definition of an
+ existing session variable. There are several subforms:
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>OWNER</literal></term>
+ <listitem>
+ <para>
+ This form changes the owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RENAME</literal></term>
+ <listitem>
+ <para>
+ This form changes the name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>SET SCHEMA</literal></term>
+ <listitem>
+ <para>
+ This form moves the session variable into another schema.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </para>
+
+ <para>
+ Only the owner or a superuser is allowed to alter a session variable.
+ In order to move a session variable from one schema to another, the user
+ must also have the <literal>CREATE</literal> privilege on the new schema (or
+ be a superuser).
+
+ In order to move the session variable ownership from one role to another,
+ the user must also be a direct or indirect member of the new
+ owning role, and that role must have the <literal>CREATE</literal> privilege
+ on the session variable's schema (or be a superuser). These restrictions
+ enforce that altering the owner doesn't do anything you couldn't do by
+ dropping and recreating the session variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <para>
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name (possibly schema-qualified) of the existing session variable
+ to alter.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_owner</replaceable></term>
+ <listitem>
+ <para>
+ The user name of the new owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_name</replaceable></term>
+ <listitem>
+ <para>
+ The new name for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_schema</replaceable></term>
+ <listitem>
+ <para>
+ The new schema for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To rename a session variable:
+<programlisting>
+ALTER VARIABLE foo RENAME TO boo;
+</programlisting>
+ </para>
+
+ <para>
+ To change the owner of the session variable <literal>boo</literal> to
+ <literal>joe</literal>:
+<programlisting>
+ALTER VARIABLE boo OWNER TO joe;
+</programlisting>
+ </para>
+
+ <para>
+ To change the schema of the session variable <literal>boo</literal> to
+ <literal>private</literal>:
+<programlisting>
+ALTER VARIABLE boo SET SCHEMA private;
+</programlisting>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ Session variables and this command in particular are a PostgreSQL extension.
+ </para>
+ </refsect1>
+
+ <refsect1 id="sql-altervariable-see-also">
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index 5b43c56b133..21cd80818fb 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -65,6 +65,7 @@ COMMENT ON
TRANSFORM FOR <replaceable>type_name</replaceable> LANGUAGE <replaceable>lang_name</replaceable> |
TRIGGER <replaceable class="parameter">trigger_name</replaceable> ON <replaceable class="parameter">table_name</replaceable> |
TYPE <replaceable class="parameter">object_name</replaceable> |
+ VARIABLE <replaceable class="parameter">object_name</replaceable> |
VIEW <replaceable class="parameter">object_name</replaceable>
} IS { <replaceable class="parameter">string_literal</replaceable> | NULL }
diff --git a/doc/src/sgml/ref/create_schema.sgml b/doc/src/sgml/ref/create_schema.sgml
index ed69298ccc6..d2bb265209b 100644
--- a/doc/src/sgml/ref/create_schema.sgml
+++ b/doc/src/sgml/ref/create_schema.sgml
@@ -103,9 +103,10 @@ CREATE SCHEMA IF NOT EXISTS AUTHORIZATION <replaceable class="parameter">role_sp
schema. Currently, only <command>CREATE
TABLE</command>, <command>CREATE VIEW</command>, <command>CREATE
INDEX</command>, <command>CREATE SEQUENCE</command>, <command>CREATE
- TRIGGER</command> and <command>GRANT</command> are accepted as clauses
- within <command>CREATE SCHEMA</command>. Other kinds of objects may
- be created in separate commands after the schema is created.
+ TRIGGER</command>, <command>GRANT</command> and <command>CREATE
+ VARIABLE</command> are accepted as clauses within <command>CREATE
+ SCHEMA</command>. Other kinds of objects may be created in separate
+ commands after the schema is created.
</para>
</listitem>
</varlistentry>
@@ -214,6 +215,11 @@ CREATE VIEW hollywood.winners AS
The <literal>IF NOT EXISTS</literal> option is a
<productname>PostgreSQL</productname> extension.
</para>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
</refsect1>
<refsect1>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
new file mode 100644
index 00000000000..6e988f2e472
--- /dev/null
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -0,0 +1,149 @@
+<!--
+doc/src/sgml/ref/create_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-createvariable">
+ <indexterm zone="sql-createvariable">
+ <primary>CREATE VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>defining</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>CREATE VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>CREATE VARIABLE</refname>
+ <refpurpose>define a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+</synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command creates a session variable.
+ Session variables, like relations, exist within a schema and their access is
+ controlled via the commands <command>GRANT</command> and <command>REVOKE</command>.
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a session variable's value returns NULL, unless its value is set to
+ something else in the current session with a <command>LET</command> command.
+ The content of a session variable is not transactional. This is the same as
+ regular variables in procedural languages.
+ </para>
+
+ <para>
+ Session variables are retrieved by the <command>SELECT</command>
+ command. Their value is set with the <command>LET</command> command.
+ </para>
+
+ <note>
+ <para>
+ Session variables can be <quote>shadowed</quote> by other identifiers.
+ For details, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </note>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+
+ <varlistentry id="sql-createvariable-if-not-exists">
+ <term><literal>IF NOT EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the name already exists. A notice is issued in
+ this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-name">
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-data_type">
+ <term><replaceable class="parameter">data_type</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the data type of the session
+ variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-collate">
+ <term><literal>COLLATE <replaceable>collation</replaceable></literal></term>
+ <listitem>
+ <para>
+ The <literal>COLLATE</literal> clause assigns a collation to the session
+ variable (which must be of a collatable data type). If not specified,
+ the data type's default collation is used.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para>
+ Use the <command>DROP VARIABLE</command> command to remove a session
+ variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ Create an date session variable <literal>var1</literal>:
+<programlisting>
+CREATE VARIABLE var1 AS date;
+</programlisting>
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
new file mode 100644
index 00000000000..5bdb3560f0b
--- /dev/null
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -0,0 +1,117 @@
+<!--
+doc/src/sgml/ref/drop_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-dropvariable">
+ <indexterm zone="sql-dropvariable">
+ <primary>DROP VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>removing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>DROP VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>DROP VARIABLE</refname>
+ <refpurpose>remove a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+DROP VARIABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ <command>DROP VARIABLE</command> removes a session variable.
+ A session variable can only be removed by its owner or a superuser.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>IF EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the session variable does not exist. A notice is
+ issued in this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of a session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>CASCADE</literal></term>
+ <listitem>
+ <para>
+ Automatically drop objects that depend on the session variable (such as
+ views), and in turn all objects that depend on those objects
+ (see <xref linkend="ddl-depend"/>).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RESTRICT</literal></term>
+ <listitem>
+ <para>
+ Refuse to drop the session variable if any objects depend on it. This is
+ the default.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To remove the session variable <literal>var1</literal>:
+
+<programlisting>
+DROP VARIABLE var1;
+</programlisting></para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>DROP VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index 999f657d5c0..c11860fa200 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -101,6 +101,12 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
[ WITH { ADMIN | INHERIT | SET } { OPTION | TRUE | FALSE } ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+GRANT { SELECT | UPDATE | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
@@ -119,8 +125,8 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
that grants privileges on a database object (table, column, view,
foreign table, sequence, database, foreign-data wrapper, foreign server,
function, procedure, procedural language, large object, configuration
- parameter, schema, tablespace, or type), and one that grants
- membership in a role. These variants are similar in many ways, but
+ parameter, schema, session variable, tablespace, or type), and one that
+ grants membership in a role. These variants are similar in many ways, but
they are different enough to be described separately.
</para>
@@ -236,9 +242,9 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
<para>
There is also an option to grant privileges on all objects of the same
type within one or more schemas. This functionality is currently supported
- only for tables, sequences, functions, and procedures. <literal>ALL
- TABLES</literal> also affects views and foreign tables, just like the
- specific-object <command>GRANT</command> command. <literal>ALL
+ only for tables, sequences, functions, procedures and variables.
+ <literal>ALL TABLES</literal> also affects views and foreign tables, just
+ like the specific-object <command>GRANT</command> command. <literal>ALL
FUNCTIONS</literal> also affects aggregate and window functions, but not
procedures, again just like the specific-object <command>GRANT</command>
command. Use <literal>ALL ROUTINES</literal> to include procedures.
@@ -518,8 +524,8 @@ GRANT admins TO joe;
</para>
<para>
- Privileges on databases, tablespaces, schemas, languages, and
- configuration parameters are
+ Privileges on databases, tablespaces, schemas, languages, session variables
+ and configuration parameters are
<productname>PostgreSQL</productname> extensions.
</para>
</refsect1>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index f7c8bc16a7f..4989cdc7ddb 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -2135,6 +2135,19 @@ SELECT $1 \parse stmt1
</listitem>
</varlistentry>
+ <varlistentry id="app-psql-meta-command-dv">
+ <term><literal>\dV[+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
+ <listitem>
+ <para>
+ Lists session variables.
+ If <replaceable class="parameter">pattern</replaceable> is
+ specified, only session variables whose names match the pattern are listed.
+ If the form <literal>\dV+</literal> is used, additional information
+ about each variable is shown, like access privileges and description.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="app-psql-meta-command-du">
<term><literal>\du[Sx+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
<listitem>
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index 8df492281a1..760fddb7c20 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -130,6 +130,14 @@ REVOKE [ { ADMIN | INHERIT | SET } OPTION FOR ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
[ CASCADE | RESTRICT ]
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ FROM { <replaceable class="parameter">role_specification</replaceable> | PUBLIC } [, ...]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+ [ CASCADE | RESTRICT ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index ff85ace83fc..25578f3946c 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -75,6 +75,7 @@
&alterType;
&alterUser;
&alterUserMapping;
+ &alterVariable;
&alterView;
&analyze;
&begin;
@@ -127,6 +128,7 @@
&createType;
&createUser;
&createUserMapping;
+ &createVariable;
&createView;
&deallocate;
&declare;
@@ -175,6 +177,7 @@
&dropType;
&dropUser;
&dropUserMapping;
+ &dropVariable;
&dropView;
&end;
&execute;
diff --git a/src/backend/catalog/Makefile b/src/backend/catalog/Makefile
index c090094ed08..2c20d60db19 100644
--- a/src/backend/catalog/Makefile
+++ b/src/backend/catalog/Makefile
@@ -45,6 +45,7 @@ OBJS = \
pg_shdepend.o \
pg_subscription.o \
pg_type.o \
+ pg_variable.o \
storage.o \
toasting.o
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 9ca8a88dc91..587be8c70c8 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -64,6 +64,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -291,6 +292,9 @@ restrict_and_check_grant(bool is_grant, AclMode avail_goptions, bool all_privs,
case OBJECT_PARAMETER_ACL:
whole_mask = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ whole_mask = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", objtype);
/* not reached, but keep compiler quiet */
@@ -535,6 +539,10 @@ ExecuteGrantStmt(GrantStmt *stmt)
all_privileges = ACL_ALL_RIGHTS_PARAMETER_ACL;
errormsg = gettext_noop("invalid privilege type %s for parameter");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) stmt->objtype);
@@ -640,6 +648,9 @@ ExecGrantStmt_oids(InternalGrant *istmt)
case OBJECT_PARAMETER_ACL:
ExecGrant_Parameter(istmt);
break;
+ case OBJECT_VARIABLE:
+ ExecGrant_common(istmt, VariableRelationId, ACL_ALL_RIGHTS_VARIABLE, NULL);
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) istmt->objtype);
@@ -760,6 +771,18 @@ objectNamesToOids(ObjectType objtype, List *objnames, bool is_grant)
objects = lappend_oid(objects, parameterId);
}
break;
+
+ case OBJECT_VARIABLE:
+ foreach_node(RangeVar, varvar, objnames)
+ {
+ Oid relOid;
+
+ relOid = LookupVariable(varvar->schemaname,
+ varvar->relname,
+ false);
+ objects = lappend_oid(objects, relOid);
+ }
+ break;
}
return objects;
@@ -846,6 +869,32 @@ objectsInSchemaToOids(ObjectType objtype, List *nspnames)
table_close(rel, AccessShareLock);
}
break;
+ case OBJECT_VARIABLE:
+ {
+ ScanKeyData key;
+ Relation rel;
+ TableScanDesc scan;
+ HeapTuple tuple;
+
+ ScanKeyInit(&key,
+ Anum_pg_variable_varnamespace,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(namespaceId));
+
+ rel = table_open(VariableRelationId, AccessShareLock);
+ scan = table_beginscan_catalog(rel, 1, &key);
+
+ while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+ {
+ Oid oid = ((Form_pg_proc) GETSTRUCT(tuple))->oid;
+
+ objects = lappend_oid(objects, oid);
+ }
+
+ table_endscan(scan);
+ table_close(rel, AccessShareLock);
+ }
+ break;
default:
/* should not happen */
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
@@ -1009,6 +1058,10 @@ ExecAlterDefaultPrivilegesStmt(ParseState *pstate, AlterDefaultPrivilegesStmt *s
all_privileges = ACL_ALL_RIGHTS_LARGEOBJECT;
errormsg = gettext_noop("invalid privilege type %s for large object");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) action->objtype);
@@ -1209,6 +1262,11 @@ SetDefaultACL(InternalDefaultACL *iacls)
if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
this_privileges = ACL_ALL_RIGHTS_LARGEOBJECT;
break;
+ case OBJECT_VARIABLE:
+ objtype = DEFACLOBJ_VARIABLE;
+ if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
+ this_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d",
@@ -1456,6 +1514,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case DEFACLOBJ_LARGEOBJECT:
iacls.objtype = OBJECT_LARGEOBJECT;
break;
+ case DEFACLOBJ_VARIABLE:
+ iacls.objtype = OBJECT_VARIABLE;
+ break;
default:
/* Shouldn't get here */
elog(ERROR, "unexpected default ACL type: %d",
@@ -1516,6 +1577,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case ParameterAclRelationId:
istmt.objtype = OBJECT_PARAMETER_ACL;
break;
+ case VariableRelationId:
+ istmt.objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unexpected object class %u", classid);
break;
@@ -2749,6 +2813,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("permission denied for type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("permission denied for session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("permission denied for view %s");
break;
@@ -2860,6 +2927,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("must be owner of type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("must be owner of session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("must be owner of view %s");
break;
@@ -3008,6 +3078,8 @@ pg_aclmask(ObjectType objtype, Oid object_oid, AttrNumber attnum, Oid roleid,
return ACL_NO_RIGHTS;
case OBJECT_TYPE:
return object_aclmask(TypeRelationId, object_oid, roleid, mask, how);
+ case OBJECT_VARIABLE:
+ return object_aclmask(VariableRelationId, object_oid, roleid, mask, how);
default:
elog(ERROR, "unrecognized object type: %d",
(int) objtype);
@@ -4271,6 +4343,10 @@ get_user_default_acl(ObjectType objtype, Oid ownerId, Oid nsp_oid)
defaclobjtype = DEFACLOBJ_LARGEOBJECT;
break;
+ case OBJECT_VARIABLE:
+ defaclobjtype = DEFACLOBJ_VARIABLE;
+ break;
+
default:
return NULL;
}
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 18316a3968b..9e0f648b74f 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -65,12 +65,14 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/comment.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "commands/extension.h"
#include "commands/policy.h"
#include "commands/publicationcmds.h"
+#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
#include "commands/trigger.h"
@@ -1444,6 +1446,10 @@ doDeletion(const ObjectAddress *object, int flags)
RemovePublicationById(object->objectId);
break;
+ case VariableRelationId:
+ DropVariableById(object->objectId);
+ break;
+
case CastRelationId:
case CollationRelationId:
case ConversionRelationId:
diff --git a/src/backend/catalog/meson.build b/src/backend/catalog/meson.build
index 1958ea9238a..ed44c877fca 100644
--- a/src/backend/catalog/meson.build
+++ b/src/backend/catalog/meson.build
@@ -32,6 +32,7 @@ backend_sources += files(
'pg_shdepend.c',
'pg_subscription.c',
'pg_type.c',
+ 'pg_variable.c',
'storage.c',
'toasting.c',
)
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index d97d632a7ef..4307cad15c7 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "common/hashfn_unstable.h"
#include "funcapi.h"
@@ -225,6 +226,7 @@ static bool TSParserIsVisibleExt(Oid prsId, bool *is_missing);
static bool TSDictionaryIsVisibleExt(Oid dictId, bool *is_missing);
static bool TSTemplateIsVisibleExt(Oid tmplId, bool *is_missing);
static bool TSConfigIsVisibleExt(Oid cfgid, bool *is_missing);
+static bool VariableIsVisibleExt(Oid varid, bool *is_missing);
static void recomputeNamespacePath(void);
static void AccessTempTableNamespace(bool force);
static void InitTempTableNamespace(void);
@@ -986,6 +988,84 @@ RelationIsVisibleExt(Oid relid, bool *is_missing)
return visible;
}
+/*
+ * VariableIsVisible
+ * Determine whether a variable (identified by OID) is visible in the
+ * current search path. Visible means "would be found by searching
+ * for the unqualified variable name".
+ */
+bool
+VariableIsVisible(Oid varid)
+{
+ return VariableIsVisibleExt(varid, NULL);
+}
+
+/*
+ * VariableIsVisibleExt
+ * As above, but if the variable isn't found and is_missing is not NULL,
+ * then set *is_missing = true and return false, instead of throwing
+ * an error. (Caller must initialize *is_missing = false.)
+ */
+static bool
+VariableIsVisibleExt(Oid varid, bool *is_missing)
+{
+ HeapTuple vartup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+ bool visible;
+
+ vartup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+ if (!HeapTupleIsValid(vartup))
+ {
+ if (is_missing != NULL)
+ {
+ *is_missing = true;
+ return false;
+ }
+
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+ }
+ varform = (Form_pg_variable) GETSTRUCT(vartup);
+
+ recomputeNamespacePath();
+
+ /*
+ * Quick check: if it ain't in the path at all, it ain't visible. We
+ * don't expect usage of session variables in the system namespace.
+ */
+ varnamespace = varform->varnamespace;
+ if (!list_member_oid(activeSearchPath, varnamespace))
+ visible = false;
+ else
+ {
+ /*
+ * If it is in the path, it might still not be visible; it could be
+ * hidden by another variable of the same name earlier in the path. So
+ * we must do a slow check for conflicting relations.
+ */
+ char *varname = NameStr(varform->varname);
+
+ visible = false;
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ if (namespaceId == varnamespace)
+ {
+ /* found it first in path */
+ visible = true;
+ break;
+ }
+ if (OidIsValid(get_varname_varid(varname, namespaceId)))
+ {
+ /* found something else first in path */
+ break;
+ }
+ }
+ }
+
+ ReleaseSysCache(vartup);
+
+ return visible;
+}
/*
* TypenameGetTypid
@@ -3289,6 +3369,133 @@ TSConfigIsVisibleExt(Oid cfgid, bool *is_missing)
return visible;
}
+/*
+ * Returns oid of session variable specified by possibly qualified identifier.
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariable(const char *nspname,
+ const char *varname,
+ bool missing_ok)
+{
+ Oid varoid = InvalidOid;
+
+ if (nspname)
+ {
+ Oid namespaceId = LookupExplicitNamespace(nspname, missing_ok);
+
+ /* if nspname is a known namespace, the variable must be there */
+ if (OidIsValid(namespaceId))
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+ }
+ }
+ else
+ {
+ /* iterate over the schemas on the search_path */
+ recomputeNamespacePath();
+
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+
+ if (OidIsValid(varoid))
+ break;
+ }
+ }
+
+ if (!OidIsValid(varoid) && !missing_ok)
+ {
+ if (nspname)
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s.%s\" does not exist",
+ nspname, varname)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" does not exist",
+ varname)));
+ }
+
+ return varoid;
+}
+
+/*
+ * Returns oid of session variable specified by possibly qualified identifier
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariableFromNameList(List *names,
+ bool missing_ok)
+{
+ char *catname = NULL;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ switch (list_length(names))
+ {
+ case 1:
+ varname = strVal(linitial(names));
+ break;
+ case 2:
+ nspname = strVal(linitial(names));
+ varname = strVal(lsecond(names));
+ break;
+ case 3:
+ catname = strVal(linitial(names));
+ nspname = strVal(lsecond(names));
+ varname = strVal(lthird(names));
+
+ /* check catalog name */
+ if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ break;
+ default:
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper session variable name (too many dotted names): %s",
+ NameListToString(names))));
+ break;
+ }
+
+ return LookupVariable(nspname, varname, missing_ok);
+}
+
+/*
+ * The input list contains names with indirection expressions used as the left
+ * part of LET statement. The following routine returns a new list with only
+ * initial strings (names) - without indirection expressions.
+ */
+List *
+NamesFromList(List *names)
+{
+ ListCell *l;
+ List *result = NIL;
+
+ foreach(l, names)
+ {
+ Node *n = lfirst(l);
+
+ if (IsA(n, String))
+ {
+ result = lappend(result, n);
+ }
+ else
+ break;
+ }
+
+ return result;
+}
/*
* DeconstructQualifiedName
@@ -5085,3 +5292,17 @@ pg_is_other_temp_schema(PG_FUNCTION_ARGS)
PG_RETURN_BOOL(isOtherTempNamespace(oid));
}
+
+Datum
+pg_variable_is_visible(PG_FUNCTION_ARGS)
+{
+ Oid oid = PG_GETARG_OID(0);
+ bool result;
+ bool is_missing = false;
+
+ result = VariableIsVisibleExt(oid, &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+ PG_RETURN_BOOL(result);
+}
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index b63fd57dc04..444892ad6ba 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -62,6 +62,7 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -636,6 +637,20 @@ static const ObjectPropertyType ObjectProperty[] =
OBJECT_USER_MAPPING,
false
},
+ {
+ "session variable",
+ VariableRelationId,
+ VariableOidIndexId,
+ VARIABLEOID,
+ VARIABLENAMENSP,
+ Anum_pg_variable_oid,
+ Anum_pg_variable_varname,
+ Anum_pg_variable_varnamespace,
+ Anum_pg_variable_varowner,
+ Anum_pg_variable_varacl,
+ OBJECT_VARIABLE,
+ true
+ }
};
/*
@@ -831,6 +846,9 @@ static const struct object_type_map
},
{
"statistics object", OBJECT_STATISTIC_EXT
+ },
+ {
+ "session variable", OBJECT_VARIABLE
}
};
@@ -856,6 +874,7 @@ static ObjectAddress get_object_address_attrdef(ObjectType objtype,
bool missing_ok);
static ObjectAddress get_object_address_type(ObjectType objtype,
TypeName *typename, bool missing_ok);
+static ObjectAddress get_object_address_variable(List *object, bool missing_ok);
static ObjectAddress get_object_address_opcf(ObjectType objtype, List *object,
bool missing_ok);
static ObjectAddress get_object_address_opf_member(ObjectType objtype,
@@ -1127,6 +1146,9 @@ get_object_address(ObjectType objtype, Node *object,
missing_ok);
address.objectSubId = 0;
break;
+ case OBJECT_VARIABLE:
+ address = get_object_address_variable(castNode(List, object), missing_ok);
+ break;
/* no default, to let compiler warn about missing case */
}
@@ -2008,17 +2030,21 @@ get_object_address_defacl(List *object, bool missing_ok)
case DEFACLOBJ_LARGEOBJECT:
objtype_str = "large objects";
break;
+ case DEFACLOBJ_VARIABLE:
+ objtype_str = "variables";
+ break;
default:
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized default ACL object type \"%c\"", objtype),
- errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
+ errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
DEFACLOBJ_RELATION,
DEFACLOBJ_SEQUENCE,
DEFACLOBJ_FUNCTION,
DEFACLOBJ_TYPE,
DEFACLOBJ_NAMESPACE,
- DEFACLOBJ_LARGEOBJECT)));
+ DEFACLOBJ_LARGEOBJECT,
+ DEFACLOBJ_VARIABLE)));
}
/*
@@ -2102,6 +2128,24 @@ textarray_to_strvaluelist(ArrayType *arr)
return list;
}
+/*
+ * Find the ObjectAddress for a session variable
+ */
+static ObjectAddress
+get_object_address_variable(List *object, bool missing_ok)
+{
+ ObjectAddress address;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ ObjectAddressSet(address, VariableRelationId, InvalidOid);
+
+ DeconstructQualifiedName(object, &nspname, &varname);
+ address.objectId = LookupVariable(nspname, varname, missing_ok);
+
+ return address;
+}
+
/*
* SQL-callable version of get_object_address
*/
@@ -2296,6 +2340,7 @@ pg_get_object_address(PG_FUNCTION_ARGS)
case OBJECT_TABCONSTRAINT:
case OBJECT_OPCLASS:
case OBJECT_OPFAMILY:
+ case OBJECT_VARIABLE:
objnode = (Node *) name;
break;
case OBJECT_ACCESS_METHOD:
@@ -2467,6 +2512,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
case OBJECT_STATISTIC_EXT:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
if (!object_ownercheck(address.classId, address.objectId, roleid))
aclcheck_error(ACLCHECK_NOT_OWNER, objtype,
NameListToString(castNode(List, object)));
@@ -3496,6 +3542,32 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
break;
}
+ case VariableRelationId:
+ {
+ char *nspname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ if (VariableIsVisible(object->objectId))
+ nspname = NULL;
+ else
+ nspname = get_namespace_name(varform->varnamespace);
+
+ appendStringInfo(&buffer, _("session variable %s"),
+ quote_qualified_identifier(nspname,
+ NameStr(varform->varname)));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
case TSParserRelationId:
{
HeapTuple tup;
@@ -3854,6 +3926,16 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
_("default privileges on new large objects belonging to role %s"),
rolename);
break;
+ case DEFACLOBJ_VARIABLE:
+ if (nspname)
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s in schema %s"),
+ rolename, nspname);
+ else
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s"),
+ rolename);
+ break;
default:
/* shouldn't get here */
if (nspname)
@@ -4670,6 +4752,10 @@ getObjectTypeDescription(const ObjectAddress *object, bool missing_ok)
appendStringInfoString(&buffer, "transform");
break;
+ case VariableRelationId:
+ appendStringInfoString(&buffer, "session variable");
+ break;
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
@@ -5780,6 +5866,10 @@ getObjectIdentityParts(const ObjectAddress *object,
appendStringInfoString(&buffer,
" on large objects");
break;
+ case DEFACLOBJ_VARIABLE:
+ appendStringInfoString(&buffer,
+ " on session variables");
+ break;
}
if (objname)
@@ -6020,6 +6110,33 @@ getObjectIdentityParts(const ObjectAddress *object,
}
break;
+ case VariableRelationId:
+ {
+ char *schema;
+ char *varname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ schema = get_namespace_name_or_temp(varform->varnamespace);
+ varname = NameStr(varform->varname);
+
+ appendStringInfo(&buffer, "%s",
+ quote_qualified_identifier(schema, varname));
+
+ if (objname)
+ *objname = list_make2(schema, pstrdup(varname));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
diff --git a/src/backend/catalog/pg_shdepend.c b/src/backend/catalog/pg_shdepend.c
index 536191284e8..c6fd1fa074f 100644
--- a/src/backend/catalog/pg_shdepend.c
+++ b/src/backend/catalog/pg_shdepend.c
@@ -46,6 +46,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
@@ -1714,6 +1715,7 @@ shdepReassignOwned_Owner(Form_pg_shdepend sdepForm, Oid newrole)
case DatabaseRelationId:
case TSConfigRelationId:
case TSDictionaryRelationId:
+ case VariableRelationId:
AlterObjectOwner_internal(sdepForm->classid,
sdepForm->objid,
newrole);
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
new file mode 100644
index 00000000000..29d967a2d5b
--- /dev/null
+++ b/src/backend/catalog/pg_variable.c
@@ -0,0 +1,251 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.c
+ * session variables
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/catalog/pg_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "catalog/dependency.h"
+#include "catalog/indexing.h"
+#include "catalog/namespace.h"
+#include "catalog/objectaccess.h"
+#include "catalog/pg_collation.h"
+#include "catalog/pg_namespace.h"
+#include "catalog/pg_variable.h"
+#include "miscadmin.h"
+#include "parser/parse_type.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+static ObjectAddress create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists);
+
+
+/*
+ * Creates entry in pg_variable table
+ */
+static ObjectAddress
+create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists)
+{
+ Acl *varacl;
+ NameData varname;
+ bool nulls[Natts_pg_variable];
+ Datum values[Natts_pg_variable];
+ Relation rel;
+ HeapTuple tup;
+ TupleDesc tupdesc;
+ ObjectAddress myself,
+ referenced;
+ ObjectAddresses *addrs;
+ Oid varid;
+
+ Assert(varName);
+ Assert(OidIsValid(varNamespace));
+ Assert(OidIsValid(varType));
+ Assert(OidIsValid(varOwner));
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ /*
+ * Check for duplicates. Note that this does not really prevent
+ * duplicates, it's here just to provide nicer error message in common
+ * case. The real protection is the unique key on the catalog.
+ */
+ if (SearchSysCacheExists2(VARIABLENAMENSP,
+ PointerGetDatum(varName),
+ ObjectIdGetDatum(varNamespace)))
+ {
+ if (if_not_exists)
+ ereport(NOTICE,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists, skipping",
+ varName)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists",
+ varName)));
+
+ table_close(rel, RowExclusiveLock);
+
+ return InvalidObjectAddress;
+ }
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, false, sizeof(nulls));
+
+ namestrcpy(&varname, varName);
+
+ varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
+
+ values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
+ values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
+ values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
+ values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
+ values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
+ values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+
+ varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
+ varNamespace);
+ if (varacl != NULL)
+ values[Anum_pg_variable_varacl - 1] = PointerGetDatum(varacl);
+ else
+ nulls[Anum_pg_variable_varacl - 1] = true;
+
+ tupdesc = RelationGetDescr(rel);
+
+ tup = heap_form_tuple(tupdesc, values, nulls);
+ CatalogTupleInsert(rel, tup);
+ Assert(OidIsValid(varid));
+
+ addrs = new_object_addresses();
+
+ ObjectAddressSet(myself, VariableRelationId, varid);
+
+ /* dependency on namespace */
+ ObjectAddressSet(referenced, NamespaceRelationId, varNamespace);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on used type */
+ ObjectAddressSet(referenced, TypeRelationId, varType);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on collation */
+ if (OidIsValid(varCollation) &&
+ varCollation != DEFAULT_COLLATION_OID)
+ {
+ ObjectAddressSet(referenced, CollationRelationId, varCollation);
+ add_exact_object_address(&referenced, addrs);
+ }
+
+ record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
+ free_object_addresses(addrs);
+
+ /* dependency on owner */
+ recordDependencyOnOwner(VariableRelationId, varid, varOwner);
+
+ /* dependencies on roles mentioned in default ACL */
+ recordDependencyOnNewAcl(VariableRelationId, varid, 0, varOwner, varacl);
+
+ /* dependency on extension */
+ recordDependencyOnCurrentExtension(&myself, false);
+
+ heap_freetuple(tup);
+
+ /* post creation hook for new function */
+ InvokeObjectPostCreateHook(VariableRelationId, varid, 0);
+
+ table_close(rel, RowExclusiveLock);
+
+ return myself;
+}
+
+/*
+ * Creates a new variable
+ *
+ * Used by CREATE VARIABLE command
+ */
+ObjectAddress
+CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
+{
+ Oid namespaceid;
+ AclResult aclresult;
+ Oid typid;
+ int32 typmod;
+ Oid varowner = GetUserId();
+ Oid collation;
+ Oid typcollation;
+ ObjectAddress variable;
+
+ namespaceid =
+ RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL);
+
+ typenameTypeIdAndMod(pstate, stmt->typeName, &typid, &typmod);
+
+ /* disallow pseudotypes */
+ if (get_typtype(typid) == TYPTYPE_PSEUDO)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("session variable cannot be pseudo-type %s",
+ format_type_be(typid))));
+
+ aclresult = object_aclcheck(TypeRelationId, typid, GetUserId(), ACL_USAGE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error_type(aclresult, typid);
+
+ typcollation = get_typcollation(typid);
+
+ if (stmt->collClause)
+ collation = LookupCollation(pstate,
+ stmt->collClause->collname,
+ stmt->collClause->location);
+ else
+ collation = typcollation;
+
+ /* complain if COLLATE is applied to an uncollatable type */
+ if (OidIsValid(collation) && !OidIsValid(typcollation))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("collations are not supported by type %s",
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->collClause->location)));
+
+ variable = create_variable(stmt->variable->relname,
+ namespaceid,
+ typid,
+ typmod,
+ varowner,
+ collation,
+ stmt->if_not_exists);
+
+ elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
+ stmt->variable->relname, variable.objectId);
+
+ return variable;
+}
+
+/*
+ * Drop variable by OID
+ */
+void
+DropVariableById(Oid varid)
+{
+ Relation rel;
+ HeapTuple tup;
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ CatalogTupleDelete(rel, &tup->t_self);
+
+ ReleaseSysCache(tup);
+
+ table_close(rel, RowExclusiveLock);
+}
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index c801c869c1c..c72a4adb07b 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/collationcmds.h"
#include "commands/dbcommands.h"
@@ -140,6 +141,10 @@ report_namespace_conflict(Oid classId, const char *name, Oid nspOid)
Assert(OidIsValid(nspOid));
msgfmt = gettext_noop("text search configuration \"%s\" already exists in schema \"%s\"");
break;
+ case VariableRelationId:
+ Assert(OidIsValid(nspOid));
+ msgfmt = gettext_noop("session variable \"%s\" already exists in schema \"%s\"");
+ break;
default:
elog(ERROR, "unsupported object class: %u", classId);
break;
@@ -435,6 +440,7 @@ ExecRenameStmt(RenameStmt *stmt)
case OBJECT_TSTEMPLATE:
case OBJECT_PUBLICATION:
case OBJECT_SUBSCRIPTION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
Relation catalog;
@@ -575,6 +581,7 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt,
case OBJECT_TSDICTIONARY:
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
+ case OBJECT_VARIABLE:
{
Relation catalog;
Oid classId;
@@ -657,6 +664,7 @@ AlterObjectNamespace_oid(Oid classId, Oid objid, Oid nspOid,
case TSDictionaryRelationId:
case TSTemplateRelationId:
case TSConfigRelationId:
+ case VariableRelationId:
{
Relation catalog;
@@ -887,6 +895,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
case OBJECT_TABLESPACE:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
diff --git a/src/backend/commands/dropcmds.c b/src/backend/commands/dropcmds.c
index ceb9a229b63..ebb585dc4a1 100644
--- a/src/backend/commands/dropcmds.c
+++ b/src/backend/commands/dropcmds.c
@@ -476,6 +476,10 @@ does_not_exist_skipping(ObjectType objtype, Node *object)
msg = gettext_noop("publication \"%s\" does not exist, skipping");
name = strVal(object);
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("session variable \"%s\" does not exist, skipping");
+ name = NameListToString(castNode(List, object));
+ break;
case OBJECT_COLUMN:
case OBJECT_DATABASE:
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index edc2c988e29..1839c1f82c5 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -2149,6 +2149,8 @@ stringify_grant_objtype(ObjectType objtype)
return "TABLESPACE";
case OBJECT_TYPE:
return "TYPE";
+ case OBJECT_VARIABLE:
+ return "VARIABLE";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
@@ -2232,6 +2234,8 @@ stringify_adefprivs_objtype(ObjectType objtype)
return "TABLESPACES";
case OBJECT_TYPE:
return "TYPES";
+ case OBJECT_VARIABLE:
+ return "VARIABLES";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
diff --git a/src/backend/commands/seclabel.c b/src/backend/commands/seclabel.c
index cee5d7bbb9c..57b4e6719c2 100644
--- a/src/backend/commands/seclabel.c
+++ b/src/backend/commands/seclabel.c
@@ -92,6 +92,7 @@ SecLabelSupportsObjectType(ObjectType objtype)
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
case OBJECT_USER_MAPPING:
+ case OBJECT_VARIABLE:
return false;
/*
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 4397123398e..dcdf2d9a520 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -52,6 +52,7 @@
#include "catalog/pg_tablespace.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "catalog/storage.h"
#include "catalog/storage_xlog.h"
#include "catalog/toasting.h"
@@ -6902,6 +6903,7 @@ ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
* (possibly nested several levels deep in composite types, arrays, etc!).
* Eventually, we'd like to propagate the check or rewrite operation
* into such tables, but for now, just error out if we find any.
+ * Also, check if "typeOid" is used as type of some session variable.
*
* Caller should provide either the associated relation of a rowtype,
* or a type name (not both) for use in the error message, if any.
@@ -6965,6 +6967,45 @@ find_composite_type_dependencies(Oid typeOid, Relation origRelation,
continue;
}
+ /* check if the type is used as type of some session variable */
+ if (pg_depend->classid == VariableRelationId)
+ {
+ Oid varid = pg_depend->objid;
+
+ if (origTypeName)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ origTypeName,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter foreign table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_RELATION ||
+ origRelation->rd_rel->relkind == RELKIND_MATVIEW ||
+ origRelation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+
+ continue;
+ }
+
/* Else, ignore dependees that aren't relations */
if (pg_depend->classid != RelationRelationId)
continue;
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 3cb3ca1cca1..473d98ff062 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -53,6 +53,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_range.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablecmds.h"
#include "commands/typecmds.h"
@@ -3369,6 +3370,20 @@ get_rels_with_domain(Oid domainOid, LOCKMODE lockmode)
}
continue;
}
+ else if (pg_depend->classid == VariableRelationId)
+ {
+ /*
+ * We cannot to validate constraint inside session variables
+ * from other sessions, so better to fail if there are any
+ * session variable, that use this domain.
+ */
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter domain \"%s\" because session variable \"%s.%s\" uses it",
+ domainTypeName,
+ get_namespace_name(get_session_variable_namespace(pg_depend->objid)),
+ get_session_variable_name(pg_depend->objid))));
+ }
/* Else, ignore dependees that aren't user columns of relations */
/* (we assume system columns are never of domain types) */
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index f1156e2fca3..2efe42b82a6 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -52,6 +52,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_am.h"
#include "catalog/pg_trigger.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/trigger.h"
#include "gramparse.h"
@@ -285,8 +286,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
ConstraintsSetStmt CopyStmt CreateAsStmt CreateCastStmt
CreateDomainStmt CreateExtensionStmt CreateGroupStmt CreateOpClassStmt
CreateOpFamilyStmt AlterOpFamilyStmt CreatePLangStmt
- CreateSchemaStmt CreateSeqStmt CreateStmt CreateStatsStmt CreateTableSpaceStmt
- CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
+ CreateSchemaStmt CreateSeqStmt CreateSessionVarStmt CreateStmt CreateStatsStmt
+ CreateTableSpaceStmt CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
CreateAssertionStmt CreateTransformStmt CreateTrigStmt CreateEventTrigStmt
CreateUserStmt CreateUserMappingStmt CreateRoleStmt CreatePolicyStmt
CreatedbStmt DeclareCursorStmt DefineStmt DeleteStmt DiscardStmt DoStmt
@@ -783,8 +784,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
UESCAPE UNBOUNDED UNCONDITIONAL UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN
UNLISTEN UNLOGGED UNTIL UPDATE USER USING
- VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
- VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
+ VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARIABLE
+ VARIABLES VARYING VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
@@ -1050,6 +1051,7 @@ stmt:
| CreatePolicyStmt
| CreatePLangStmt
| CreateSchemaStmt
+ | CreateSessionVarStmt
| CreateSeqStmt
| CreateStmt
| CreateSubscriptionStmt
@@ -1592,6 +1594,7 @@ schema_stmt:
| CreateTrigStmt
| GrantStmt
| ViewStmt
+ | CreateSessionVarStmt
;
@@ -5268,6 +5271,34 @@ create_extension_opt_item:
}
;
+/*****************************************************************************
+ *
+ * QUERY :
+ * CREATE VARIABLE varname [AS] type
+ *
+ *****************************************************************************/
+
+CreateSessionVarStmt:
+ CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $3;
+ n->typeName = $5;
+ n->collClause = (CollateClause *) $6;
+ n->if_not_exists = false;
+ $$ = (Node *) n;
+ }
+ | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $6;
+ n->typeName = $8;
+ n->collClause = (CollateClause *) $9;
+ n->if_not_exists = true;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
@@ -7059,6 +7090,7 @@ object_type_any_name:
| TEXT_P SEARCH DICTIONARY { $$ = OBJECT_TSDICTIONARY; }
| TEXT_P SEARCH TEMPLATE { $$ = OBJECT_TSTEMPLATE; }
| TEXT_P SEARCH CONFIGURATION { $$ = OBJECT_TSCONFIGURATION; }
+ | VARIABLE { $$ = OBJECT_VARIABLE; }
;
/*
@@ -7935,6 +7967,14 @@ privilege_target:
n->objs = $2;
$$ = n;
}
+ | VARIABLE qualified_name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_OBJECT;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $2;
+ $$ = n;
+ }
| ALL TABLES IN_P SCHEMA name_list
{
PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
@@ -7980,6 +8020,14 @@ privilege_target:
n->objs = $5;
$$ = n;
}
+ | ALL VARIABLES IN_P SCHEMA name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_ALL_IN_SCHEMA;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $5;
+ $$ = n;
+ }
;
@@ -8178,6 +8226,7 @@ defacl_privilege_target:
| TYPES_P { $$ = OBJECT_TYPE; }
| SCHEMAS { $$ = OBJECT_SCHEMA; }
| LARGE_P OBJECTS_P { $$ = OBJECT_LARGEOBJECT; }
+ | VARIABLES { $$ = OBJECT_VARIABLE; }
;
@@ -9966,6 +10015,24 @@ RenameStmt: ALTER AGGREGATE aggregate_with_argtypes RENAME TO name
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newname = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newname = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
opt_column: COLUMN
@@ -10327,6 +10394,24 @@ AlterObjectSchemaStmt:
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newschema = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newschema = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
/*****************************************************************************
@@ -10608,6 +10693,14 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec
n->newowner = $6;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name OWNER TO RoleSpec
+ {
+ AlterOwnerStmt *n = makeNode(AlterOwnerStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newowner = $6;
+ $$ = (Node *)n;
+ }
;
@@ -18018,6 +18111,8 @@ unreserved_keyword:
| VALIDATE
| VALIDATOR
| VALUE_P
+ | VARIABLE
+ | VARIABLES
| VARYING
| VERSION_P
| VIEW
@@ -18674,6 +18769,8 @@ bare_label_keyword:
| VALUE_P
| VALUES
| VARCHAR
+ | VARIABLE
+ | VARIABLES
| VARIADIC
| VERBOSE
| VERSION_P
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index 62015431fdf..b6cbe354c51 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -105,6 +105,7 @@ typedef struct
List *indexes; /* CREATE INDEX items */
List *triggers; /* CREATE TRIGGER items */
List *grants; /* GRANT items */
+ List *variables; /* CREATE VARIABLE items */
} CreateSchemaStmtContext;
@@ -4091,6 +4092,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.indexes = NIL;
cxt.triggers = NIL;
cxt.grants = NIL;
+ cxt.variables = NIL;
/*
* Run through each schema element in the schema element list. Separate
@@ -4159,6 +4161,15 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.grants = lappend(cxt.grants, element);
break;
+ case T_CreateSessionVarStmt:
+ {
+ CreateSessionVarStmt *elp = (CreateSessionVarStmt *) element;
+
+ setSchemaName(cxt.schemaname, &elp->variable->schemaname);
+ cxt.variables = lappend(cxt.variables, element);
+ }
+ break;
+
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(element));
@@ -4172,6 +4183,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
result = list_concat(result, cxt.indexes);
result = list_concat(result, cxt.triggers);
result = list_concat(result, cxt.grants);
+ result = list_concat(result, cxt.variables);
return result;
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 25fe3d58016..99a51877d34 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -23,6 +23,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_inherits.h"
+#include "catalog/pg_variable.h"
#include "catalog/toasting.h"
#include "commands/alter.h"
#include "commands/async.h"
@@ -182,6 +183,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CreateRangeStmt:
case T_CreateRoleStmt:
case T_CreateSchemaStmt:
+ case T_CreateSessionVarStmt:
case T_CreateSeqStmt:
case T_CreateStatsStmt:
case T_CreateStmt:
@@ -1389,6 +1391,10 @@ ProcessUtilitySlow(ParseState *pstate,
}
break;
+ case T_CreateSessionVarStmt:
+ address = CreateVariable(pstate, (CreateSessionVarStmt *) parsetree);
+ break;
+
/*
* ************* object creation / destruction **************
*/
@@ -2341,6 +2347,9 @@ AlterObjectTypeCommandTag(ObjectType objtype)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_ALTER_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_ALTER_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
break;
@@ -2649,6 +2658,9 @@ CreateCommandTag(Node *parsetree)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_DROP_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_DROP_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
@@ -3225,6 +3237,10 @@ CreateCommandTag(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ tag = CMDTAG_CREATE_VARIABLE;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
@@ -3759,6 +3775,10 @@ GetCommandLogLevel(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ lev = LOGSTMT_DDL;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index ba14713fef2..6ce3b937dae 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -31,6 +31,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/proclang.h"
#include "commands/tablespace.h"
@@ -129,6 +130,8 @@ static AclMode convert_type_priv_string(text *priv_type_text);
static AclMode convert_parameter_priv_string(text *priv_text);
static AclMode convert_largeobject_priv_string(text *priv_text);
static AclMode convert_role_priv_string(text *priv_type_text);
+static Oid convert_session_variable_name(text *varname);
+static AclMode convert_session_variable_priv_string(text *priv_type_text);
static AclResult pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode);
static void RoleMembershipCacheCallback(Datum arg, int cacheid, uint32 hashvalue);
@@ -851,6 +854,10 @@ acldefault(ObjectType objtype, Oid ownerId)
world_default = ACL_NO_RIGHTS;
owner_default = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ world_default = ACL_NO_RIGHTS;
+ owner_default = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", (int) objtype);
world_default = ACL_NO_RIGHTS; /* keep compiler quiet */
@@ -948,6 +955,9 @@ acldefault_sql(PG_FUNCTION_ARGS)
case 'T':
objtype = OBJECT_TYPE;
break;
+ case 'V':
+ objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type abbreviation: %c", objtypec);
}
@@ -5016,6 +5026,217 @@ pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode)
return ACLCHECK_NO_PRIV;
}
+/*
+ * has_session_variable_privilege variants
+ * These are all named "has_session_variable_privilege" at the SQL level.
+ * They take various combinations of variable name, variable OID,
+ * user name, user OID, or implicit user = current_user.
+ *
+ * The result is a boolean value: true if user has the indicated
+ * privilege, false if not, or NULL if session variable doesn't
+ * exists.
+ */
+
+/*
+ * has_session_variable_privilege_name_name
+ * Check user privileges on a session variable given
+ * name username, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_name(PG_FUNCTION_ARGS)
+{
+ Name rolename = PG_GETARG_NAME(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*rolename));
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name
+ * Check user privileges on a session variable given
+ * text session variable and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_name(PG_FUNCTION_ARGS)
+{
+ text *varname = PG_GETARG_TEXT_PP(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name_id
+ * Check user privileges on a session variable given
+ * name usename, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_id(PG_FUNCTION_ARGS)
+{
+ Name username = PG_GETARG_NAME(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*username));
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id
+ * Check user privileges on a session variable given
+ * session variable oid, and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_id(PG_FUNCTION_ARGS)
+{
+ Oid varid = PG_GETARG_OID(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_name
+ * Check user privileges on a session variable given
+ * roleid, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_name(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_id
+ * Check user privileges on a session variable given
+ * roleid, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_id(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * Given a session variable name expressed as a string, look it up and return
+ * Oid
+ */
+static Oid
+convert_session_variable_name(text *varname)
+{
+ return LookupVariableFromNameList(textToQualifiedNameList(varname), true);
+}
+
+/*
+ * convert_variable_priv_string
+ * Convert text string to AclMode value.
+ */
+static AclMode
+convert_session_variable_priv_string(text *priv_type_text)
+{
+ static const priv_map session_variable_priv_map[] = {
+ {"SELECT", ACL_SELECT},
+ {"SELECT WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_SELECT)},
+ {"UPDATE", ACL_UPDATE},
+ {"UPDATE WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_UPDATE)},
+ {NULL, 0}
+ };
+
+ return convert_any_priv_string(priv_type_text, session_variable_priv_map);
+}
/*
* initialization function (called by InitPostgres)
diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index 82031c1e8e5..e04bb56ff06 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -39,6 +39,7 @@
#include "catalog/pg_subscription.h"
#include "catalog/pg_transform.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "utils/array.h"
@@ -3797,3 +3798,115 @@ get_subscription_name(Oid subid, bool missing_ok)
return subname;
}
+
+/* ---------- PG_VARIABLE CACHE ---------- */
+
+/*
+ * get_varname_varid
+ * Given name and namespace of variable, look up the OID.
+ */
+Oid
+get_varname_varid(const char *varname, Oid varnamespace)
+{
+ return GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(varnamespace));
+}
+
+/*
+ * get_session_variable_name
+ * Returns a palloc'd copy of the name of a given session variable.
+ */
+char *
+get_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = pstrdup(NameStr(varform->varname));
+
+ ReleaseSysCache(tup);
+
+ return varname;
+}
+
+/*
+ * get_session_variable_namespace
+ * Returns the pg_namespace OID associated with a given session variable.
+ */
+Oid
+get_session_variable_namespace(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varnamespace = varform->varnamespace;
+
+ ReleaseSysCache(tup);
+
+ return varnamespace;
+}
+
+/*
+ * Returns the type of the given session variable.
+ */
+Oid
+get_session_variable_type(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid vartype;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ vartype = varform->vartype;
+
+ ReleaseSysCache(tup);
+
+ return vartype;
+}
+
+/*
+ * Returns the type, typmod and collid of the given session variable.
+ */
+void
+get_session_variable_type_typmod_collid(Oid varid, Oid *typid, int32 *typmod,
+ Oid *collid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ *typid = varform->vartype;
+ *typmod = varform->vartypmod;
+ *collid = varform->varcollation;
+
+ ReleaseSysCache(tup);
+}
diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c
index 56b6c368acf..ba6b19dc9af 100644
--- a/src/bin/pg_dump/common.c
+++ b/src/bin/pg_dump/common.c
@@ -246,6 +246,9 @@ getSchemaData(Archive *fout, int *numTablesPtr)
pg_log_info("reading subscription membership of tables");
getSubscriptionTables(fout);
+ pg_log_info("reading variables");
+ getVariables(fout);
+
free(inhinfo); /* not needed any longer */
*numTablesPtr = numTables;
diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index ab0e9e6da3c..1ffc6549012 100644
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -512,6 +512,12 @@ do { \
CONVERT_PRIV('r', "SELECT");
CONVERT_PRIV('w', "UPDATE");
}
+ else if (strcmp(type, "VARIABLE") == 0 ||
+ strcmp(type, "VARIABLES") == 0)
+ {
+ CONVERT_PRIV('r', "SELECT");
+ CONVERT_PRIV('w', "UPDATE");
+ }
else
abort();
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index 8586cdaf541..8009845f0bb 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -134,12 +134,14 @@ typedef struct _restoreOptions
int selFunction;
int selTrigger;
int selTable;
+ int selVariable;
SimpleStringList indexNames;
SimpleStringList functionNames;
SimpleStringList schemaNames;
SimpleStringList schemaExcludeNames;
SimpleStringList triggerNames;
SimpleStringList tableNames;
+ SimpleStringList variableNames;
int useDB;
ConnParams cparams; /* parameters to use if useDB */
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index f961162f365..4f319571459 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -3179,6 +3179,14 @@ _tocEntryRequired(TocEntry *te, teSection curSection, ArchiveHandle *AH)
!simple_string_list_member(&ropt->triggerNames, te->tag))
return 0;
}
+ else if (strcmp(te->desc, "VARIABLE") == 0)
+ {
+ if (!ropt->selVariable)
+ return 0;
+ if (ropt->variableNames.head != NULL &&
+ !simple_string_list_member(&ropt->variableNames, te->tag))
+ return 0;
+ }
else
return 0;
}
@@ -3742,6 +3750,7 @@ _getObjectDescription(PQExpBuffer buf, const TocEntry *te)
strcmp(type, "TEXT SEARCH DICTIONARY") == 0 ||
strcmp(type, "TEXT SEARCH CONFIGURATION") == 0 ||
strcmp(type, "TYPE") == 0 ||
+ strcmp(type, "VARIABLE") == 0 ||
strcmp(type, "VIEW") == 0 ||
/* non-schema-specified objects */
strcmp(type, "DATABASE") == 0 ||
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 8e6364d32d7..3e013a688ce 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -368,6 +368,7 @@ static void dumpPublication(Archive *fout, const PublicationInfo *pubinfo);
static void dumpPublicationTable(Archive *fout, const PublicationRelInfo *pubrinfo);
static void dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo);
static void dumpSubscriptionTable(Archive *fout, const SubRelInfo *subrinfo);
+static void dumpVariable(Archive *fout, const VariableInfo *varinfo);
static void dumpDatabase(Archive *fout);
static void dumpDatabaseConfig(Archive *AH, PQExpBuffer outbuf,
const char *dbname, Oid dboid);
@@ -5510,6 +5511,188 @@ get_next_possible_free_pg_type_oid(Archive *fout, PQExpBuffer upgrade_query)
return next_possible_free_oid;
}
+/*
+ * getVariables
+ * get information about variables
+ */
+void
+getVariables(Archive *fout)
+{
+ PQExpBuffer query;
+ PGresult *res;
+ VariableInfo *varinfo;
+ int i_tableoid;
+ int i_oid;
+ int i_varname;
+ int i_varnamespace;
+ int i_vartype;
+ int i_vartypname;
+ int i_varowner;
+ int i_varcollation;
+ int i_varacl;
+ int i_acldefault;
+ int i,
+ ntups;
+
+ if (fout->remoteVersion < 180000)
+ return;
+
+ query = createPQExpBuffer();
+
+ /* get the variables in current database */
+ appendPQExpBuffer(query,
+ "SELECT v.tableoid, v.oid, v.varname,\n"
+ " v.varnamespace, v.vartype,\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n"
+ " CASE WHEN v.varcollation <> t.typcollation "
+ " THEN v.varcollation\n"
+ " ELSE 0\n"
+ " END AS varcollation,\n"
+ " v.varowner, v.varacl,\n"
+ " acldefault('V', v.varowner) AS acldefault\n"
+ "FROM pg_catalog.pg_variable v\n"
+ "JOIN pg_catalog.pg_type t "
+ "ON (v.vartype = t.oid)");
+
+ res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK);
+
+ ntups = PQntuples(res);
+
+ i_tableoid = PQfnumber(res, "tableoid");
+ i_oid = PQfnumber(res, "oid");
+ i_varname = PQfnumber(res, "varname");
+ i_varnamespace = PQfnumber(res, "varnamespace");
+ i_vartype = PQfnumber(res, "vartype");
+ i_vartypname = PQfnumber(res, "vartypname");
+ i_varcollation = PQfnumber(res, "varcollation");
+
+ i_varowner = PQfnumber(res, "varowner");
+ i_varacl = PQfnumber(res, "varacl");
+ i_acldefault = PQfnumber(res, "acldefault");
+
+ varinfo = pg_malloc(ntups * sizeof(VariableInfo));
+
+ for (i = 0; i < ntups; i++)
+ {
+ TypeInfo *vtype;
+
+ varinfo[i].dobj.objType = DO_VARIABLE;
+ varinfo[i].dobj.catId.tableoid =
+ atooid(PQgetvalue(res, i, i_tableoid));
+ varinfo[i].dobj.catId.oid = atooid(PQgetvalue(res, i, i_oid));
+ AssignDumpId(&varinfo[i].dobj);
+ varinfo[i].dobj.name = pg_strdup(PQgetvalue(res, i, i_varname));
+ varinfo[i].dobj.namespace =
+ findNamespace(atooid(PQgetvalue(res, i, i_varnamespace)));
+
+ varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype));
+ varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname));
+ varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
+
+ varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
+ varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
+ varinfo[i].dacl.privtype = 0;
+ varinfo[i].dacl.initprivs = NULL;
+ varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner));
+
+ /* do not try to dump ACL if no ACL exists */
+ if (!PQgetisnull(res, i, i_varacl))
+ varinfo[i].dobj.components |= DUMP_COMPONENT_ACL;
+
+ if (strlen(varinfo[i].rolname) == 0)
+ pg_log_warning("owner of variable \"%s\" appears to be invalid",
+ varinfo[i].dobj.name);
+
+ /* decide whether we want to dump it */
+ selectDumpableObject(&(varinfo[i].dobj), fout);
+
+ vtype = findTypeByOid(varinfo[i].vartype);
+ addObjectDependency(&varinfo[i].dobj, vtype->dobj.dumpId);
+ }
+ PQclear(res);
+
+ destroyPQExpBuffer(query);
+}
+
+/*
+ * dumpVariable
+ * dump the definition of the given session variable
+ */
+static void
+dumpVariable(Archive *fout, const VariableInfo *varinfo)
+{
+ DumpOptions *dopt = fout->dopt;
+
+ PQExpBuffer delq;
+ PQExpBuffer query;
+ char *qualvarname;
+ const char *vartypname;
+ Oid varcollation;
+
+ /* skip if not to be dumped */
+ if (!varinfo->dobj.dump || !dopt->dumpSchema)
+ return;
+
+ delq = createPQExpBuffer();
+ query = createPQExpBuffer();
+
+ qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
+ vartypname = varinfo->vartypname;
+ varcollation = varinfo->varcollation;
+
+ appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
+ qualvarname);
+
+ appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s",
+ qualvarname, vartypname);
+
+ if (OidIsValid(varcollation))
+ {
+ CollInfo *coll;
+
+ coll = findCollationByOid(varcollation);
+ if (coll)
+ appendPQExpBuffer(query, " COLLATE %s",
+ fmtQualifiedDumpable(coll));
+ }
+
+ appendPQExpBuffer(query, ";\n");
+
+ if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
+ ArchiveEntry(fout, varinfo->dobj.catId, varinfo->dobj.dumpId,
+ ARCHIVE_OPTS(.tag = varinfo->dobj.name,
+ .namespace = varinfo->dobj.namespace->dobj.name,
+ .owner = varinfo->rolname,
+ .description = "VARIABLE",
+ .section = SECTION_PRE_DATA,
+ .createStmt = query->data,
+ .dropStmt = delq->data));
+
+ /* dump comment if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_COMMENT)
+ dumpComment(fout, "VARIABLE", qualvarname,
+ NULL, varinfo->rolname,
+ varinfo->dobj.catId, 0, varinfo->dobj.dumpId);
+
+ /* dump ACL if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_ACL)
+ {
+ char *qvarname = pg_strdup(fmtId(varinfo->dobj.name));
+
+ dumpACL(fout, varinfo->dobj.dumpId, InvalidDumpId, "VARIABLE",
+ qvarname, NULL,
+ varinfo->dobj.namespace->dobj.name, NULL, varinfo->rolname,
+ &varinfo->dacl);
+
+ free(qvarname);
+ }
+
+ destroyPQExpBuffer(delq);
+ destroyPQExpBuffer(query);
+
+ free(qualvarname);
+}
+
static void
binary_upgrade_set_type_oids_by_type_oid(Archive *fout,
PQExpBuffer upgrade_buffer,
@@ -11375,6 +11558,9 @@ dumpDumpableObject(Archive *fout, DumpableObject *dobj)
case DO_REL_STATS:
dumpRelationStats(fout, (const RelStatsInfo *) dobj);
break;
+ case DO_VARIABLE:
+ dumpVariable(fout, (VariableInfo *) dobj);
+ break;
case DO_PRE_DATA_BOUNDARY:
case DO_POST_DATA_BOUNDARY:
/* never dumped, nothing to do */
@@ -15829,6 +16015,9 @@ dumpDefaultACL(Archive *fout, const DefaultACLInfo *daclinfo)
case DEFACLOBJ_LARGEOBJECT:
type = "LARGE OBJECTS";
break;
+ case DEFACLOBJ_VARIABLE:
+ type = "VARIABLES";
+ break;
default:
/* shouldn't get here */
pg_fatal("unrecognized object type in default privileges: %d",
@@ -19546,6 +19735,7 @@ addBoundaryDependencies(DumpableObject **dobjs, int numObjs,
case DO_CONVERSION:
case DO_TABLE:
case DO_TABLE_ATTACH:
+ case DO_VARIABLE:
case DO_ATTRDEF:
case DO_PROCLANG:
case DO_CAST:
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index e6f0f86a459..0821066b3b0 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -53,6 +53,7 @@ typedef enum
DO_TABLE,
DO_TABLE_ATTACH,
DO_ATTRDEF,
+ DO_VARIABLE,
DO_INDEX,
DO_INDEX_ATTACH,
DO_STATSEXT,
@@ -732,6 +733,19 @@ typedef struct _SubRelInfo
char *srsublsn;
} SubRelInfo;
+/*
+ * The VariableInfo struct is used to represent session variables
+ */
+typedef struct _VariableInfo
+{
+ DumpableObject dobj;
+ DumpableAcl dacl;
+ Oid vartype;
+ char *vartypname;
+ Oid varcollation;
+ const char *rolname; /* name of owner, or empty string */
+} VariableInfo;
+
/*
* common utility functions
*/
@@ -815,5 +829,6 @@ extern void getPublicationTables(Archive *fout, TableInfo tblinfo[],
int numTables);
extern void getSubscriptions(Archive *fout);
extern void getSubscriptionTables(Archive *fout);
+extern void getVariables(Archive *fout);
#endif /* PG_DUMP_H */
diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c
index 0b0977788f1..b34f3418f64 100644
--- a/src/bin/pg_dump/pg_dump_sort.c
+++ b/src/bin/pg_dump/pg_dump_sort.c
@@ -77,6 +77,7 @@ enum dbObjectTypePriorities
PRIO_DUMMY_TYPE,
PRIO_ATTRDEF,
PRIO_LARGE_OBJECT,
+ PRIO_VARIABLE,
PRIO_PRE_DATA_BOUNDARY, /* boundary! */
PRIO_TABLE_DATA,
PRIO_SEQUENCE_SET,
@@ -119,6 +120,7 @@ static const int dbObjectTypePriority[] =
[DO_TABLE] = PRIO_TABLE,
[DO_TABLE_ATTACH] = PRIO_TABLE_ATTACH,
[DO_ATTRDEF] = PRIO_ATTRDEF,
+ [DO_VARIABLE] = PRIO_VARIABLE,
[DO_INDEX] = PRIO_INDEX,
[DO_INDEX_ATTACH] = PRIO_INDEX_ATTACH,
[DO_STATSEXT] = PRIO_STATSEXT,
@@ -1533,6 +1535,11 @@ describeDumpableObject(DumpableObject *obj, char *buf, int bufsize)
"RELATION STATISTICS FOR %s (ID %d OID %u)",
obj->name, obj->dumpId, obj->catId.oid);
return;
+ case DO_VARIABLE:
+ snprintf(buf, bufsize,
+ "VARIABLE %s (ID %d OID %u)",
+ obj->name, obj->dumpId, obj->catId.oid);
+ return;
}
/* shouldn't get here */
snprintf(buf, bufsize,
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 576326daec7..1c4e79b6a39 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -901,6 +901,16 @@ my %tests = (
unlike => { no_privs => 1, },
},
+ 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC'
+ => {
+ create_order => 56,
+ create_sql => 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;',
+ regexp => qr/^
+ \QALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;\E/xm,
+ like => { %full_runs, section_post_data => 1, },
+ unlike => { no_privs => 1, },
+ },
+
'ALTER ROLE regress_dump_test_role' => {
regexp => qr/^
\QALTER ROLE regress_dump_test_role WITH \E
@@ -1797,6 +1807,23 @@ my %tests = (
},
},
+ 'COMMENT ON VARIABLE dump_test.variable1' => {
+ create_order => 71,
+ create_sql => 'COMMENT ON VARIABLE dump_test.variable1
+ IS \'comment on variable\';',
+ regexp =>
+ qr/^\QCOMMENT ON VARIABLE dump_test.variable1 IS 'comment on variable';\E/m,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'COPY test_table' => {
create_order => 4,
create_sql => 'INSERT INTO dump_test.test_table (col1) '
@@ -4105,6 +4132,24 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable1 AS integer;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable1 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
@@ -4569,6 +4614,25 @@ my %tests = (
like => {},
},
+ 'GRANT SELECT ON VARIABLE dump_test.variable1' => {
+ create_order => 73,
+ create_sql =>
+ 'GRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;',
+ regexp => qr/^
+ \QGRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;\E
+ /xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ no_privs => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'REFRESH MATERIALIZED VIEW matview' => {
regexp => qr/^\QREFRESH MATERIALIZED VIEW dump_test.matview;\E/m,
like =>
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index a8a13c2b88b..cfcaa66f57d 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -1246,6 +1246,9 @@ exec_command_d(PsqlScanState scan_state, bool active_branch, const char *cmd)
break;
}
break;
+ case 'V': /* Variables */
+ success = listVariables(pattern, show_verbose);
+ break;
case 'x': /* Extensions */
if (show_verbose)
success = listExtensionContents(pattern);
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 8970677ac64..8d5f63322b8 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -1223,7 +1223,7 @@ listDefaultACLs(const char *pattern)
"SELECT pg_catalog.pg_get_userbyid(d.defaclrole) AS \"%s\",\n"
" n.nspname AS \"%s\",\n"
" CASE d.defaclobjtype "
- " WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s'"
+ " WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s'"
" WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
" ",
gettext_noop("Owner"),
@@ -1240,6 +1240,8 @@ listDefaultACLs(const char *pattern)
gettext_noop("schema"),
DEFACLOBJ_LARGEOBJECT,
gettext_noop("large object"),
+ DEFACLOBJ_VARIABLE,
+ gettext_noop("session variable"),
gettext_noop("Type"));
printACLColumn(&buf, "d.defaclacl");
@@ -5310,6 +5312,102 @@ error_return:
return false;
}
+/*
+ * \dV
+ *
+ * listVariables()
+ */
+bool
+listVariables(const char *pattern, bool verbose)
+{
+ PQExpBufferData buf;
+ PGresult *res;
+ printQueryOpt myopt = pset.popt;
+ static const bool translate_columns[] = {false, false, false, false, false, false, false};
+
+ if (pset.sversion < 180000)
+ {
+ char sverbuf[32];
+
+ pg_log_error("The server (version %s) does not support session variables.",
+ formatPGVersionNumber(pset.sversion, false,
+ sverbuf, sizeof(sverbuf)));
+ return true;
+ }
+
+ initPQExpBuffer(&buf);
+
+ printfPQExpBuffer(&buf,
+ "SELECT n.nspname as \"%s\",\n"
+ " v.varname as \"%s\",\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n"
+ " (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
+ " WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
+ " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n",
+ gettext_noop("Schema"),
+ gettext_noop("Name"),
+ gettext_noop("Type"),
+ gettext_noop("Collation"),
+ gettext_noop("Owner"));
+
+ if (verbose)
+ {
+ appendPQExpBufferStr(&buf, ",\n ");
+ printACLColumn(&buf, "v.varacl");
+ appendPQExpBuffer(&buf,
+ ",\n pg_catalog.obj_description(v.oid, 'pg_variable') AS \"%s\"",
+ gettext_noop("Description"));
+ }
+
+ appendPQExpBufferStr(&buf,
+ "\nFROM pg_catalog.pg_variable v"
+ "\n LEFT JOIN pg_catalog.pg_namespace n ON n.oid = v.varnamespace");
+
+ appendPQExpBufferStr(&buf, "\nWHERE true\n");
+ if (!pattern)
+ appendPQExpBufferStr(&buf, " AND n.nspname <> 'pg_catalog'\n"
+ " AND n.nspname <> 'information_schema'\n");
+
+ if (!validateSQLNamePattern(&buf, pattern, true, false,
+ "n.nspname", "v.varname", NULL,
+ "pg_catalog.pg_variable_is_visible(v.oid)",
+ NULL, 3))
+ return false;
+
+ appendPQExpBufferStr(&buf, "ORDER BY 1,2;");
+
+ res = PSQLexec(buf.data);
+ termPQExpBuffer(&buf);
+ if (!res)
+ return false;
+
+ /*
+ * Most functions in this file are content to print an empty table when
+ * there are no matching objects. We intentionally deviate from that
+ * here, but only in !quiet mode, for historical reasons.
+ */
+ if (PQntuples(res) == 0 && !pset.quiet)
+ {
+ if (pattern)
+ pg_log_error("Did not find any session variable named \"%s\".",
+ pattern);
+ else
+ pg_log_error("Did not find any session variables.");
+ }
+ else
+ {
+ myopt.nullPrint = NULL;
+ myopt.title = _("List of variables");
+ myopt.translate_header = true;
+ myopt.translate_columns = translate_columns;
+ myopt.n_translate_columns = lengthof(translate_columns);
+
+ printQuery(res, &myopt, pset.queryFout, false, pset.logfile);
+ }
+
+ PQclear(res);
+ return true;
+}
/*
* \dFp
diff --git a/src/bin/psql/describe.h b/src/bin/psql/describe.h
index 18ecaa60949..55ced4aab7b 100644
--- a/src/bin/psql/describe.h
+++ b/src/bin/psql/describe.h
@@ -149,4 +149,7 @@ extern bool listOpFamilyFunctions(const char *access_method_pattern,
/* \dl or \lo_list */
extern bool listLargeObjects(bool verbose);
+/* \dV */
+extern bool listVariables(const char *pattern, bool varbose);
+
#endif /* DESCRIBE_H */
diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index fe96e3e1de9..889f6cb2dc4 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -274,6 +274,7 @@ slashUsage(unsigned short int pager)
HELP0(" \\dT[Sx+] [PATTERN] list data types\n");
HELP0(" \\du[Sx+] [PATTERN] list roles\n");
HELP0(" \\dv[Sx+] [PATTERN] list views\n");
+ HELP0(" \\dV[x+] [PATTERN] list session variables\n");
HELP0(" \\dx[x+] [PATTERN] list extensions\n");
HELP0(" \\dX[x] [PATTERN] list extended statistics\n");
HELP0(" \\dy[x+] [PATTERN] list event triggers\n");
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index c916b9299a8..94bd86c01b9 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -970,6 +970,13 @@ static const SchemaQuery Query_for_trigger_of_table = {
.refnamespace = "c1.relnamespace",
};
+static const SchemaQuery Query_for_list_of_variables = {
+ .min_server_version = 180000,
+ .catname = "pg_catalog.pg_variable v",
+ .viscondition = "pg_catalog.pg_variable_is_visible(v.oid)",
+ .namespace = "v.varnamespace",
+ .result = "v.varname",
+};
/*
* Queries to get lists of names of various kinds of things, possibly
@@ -1318,6 +1325,7 @@ static const pgsql_thing_t words_after_create[] = {
* TABLE ... */
{"USER", Query_for_list_of_roles, NULL, NULL, Keywords_for_user_thing},
{"USER MAPPING FOR", NULL, NULL, NULL},
+ {"VARIABLE", NULL, NULL, &Query_for_list_of_variables},
{"VIEW", NULL, NULL, &Query_for_list_of_views},
{NULL} /* end of list */
};
@@ -1883,7 +1891,7 @@ psql_completion(const char *text, int start, int end)
"\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL",
"\\dm", "\\dn", "\\do", "\\dO", "\\dp", "\\dP", "\\dPi", "\\dPt",
"\\drds", "\\drg", "\\dRs", "\\dRp", "\\ds",
- "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy",
+ "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy", "\\dV",
"\\echo", "\\edit", "\\ef", "\\elif", "\\else", "\\encoding",
"\\endif", "\\endpipeline", "\\errverbose", "\\ev",
"\\f", "\\flush", "\\flushrequest",
@@ -2586,6 +2594,9 @@ match_previous_words(int pattern_id,
"ALL");
else if (Matches("ALTER", "SYSTEM", "SET", MatchAny))
COMPLETE_WITH("TO");
+ /* ALTER VARIABLE <name> */
+ else if (Matches("ALTER", "VARIABLE", MatchAny))
+ COMPLETE_WITH("OWNER TO", "RENAME TO", "SET SCHEMA");
/* ALTER VIEW <name> */
else if (Matches("ALTER", "VIEW", MatchAny))
COMPLETE_WITH("ALTER COLUMN", "OWNER TO", "RENAME", "RESET", "SET");
@@ -3169,7 +3180,7 @@ match_previous_words(int pattern_id,
"ROUTINE", "RULE", "SCHEMA", "SEQUENCE", "SERVER",
"STATISTICS", "SUBSCRIPTION", "TABLE",
"TABLESPACE", "TEXT SEARCH", "TRANSFORM FOR",
- "TRIGGER", "TYPE", "VIEW");
+ "TRIGGER", "TYPE", "VARIABLE", "VIEW");
else if (Matches("COMMENT", "ON", "ACCESS", "METHOD"))
COMPLETE_WITH_QUERY(Query_for_list_of_access_methods);
else if (Matches("COMMENT", "ON", "CONSTRAINT"))
@@ -3979,6 +3990,13 @@ match_previous_words(int pattern_id,
else if (TailMatches("=", MatchAnyExcept("*)")))
COMPLETE_WITH(",", ")");
}
+/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
+ /* Complete CREATE VARIABLE <name> with AS */
+ else if (TailMatches("CREATE", "VARIABLE", MatchAny))
+ COMPLETE_WITH("AS");
+ else if (TailMatches("VARIABLE", MatchAny, "AS"))
+ /* Complete CREATE VARIABLE <name> with AS types */
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
/* CREATE VIEW --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE [ OR REPLACE ] VIEW <name> with AS or WITH */
@@ -4256,6 +4274,12 @@ match_previous_words(int pattern_id,
else if (Matches("DROP", "TRANSFORM", "FOR", MatchAny, "LANGUAGE", MatchAny))
COMPLETE_WITH("CASCADE", "RESTRICT");
+ /* DROP VARIABLE */
+ else if (Matches("DROP", "VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ else if (Matches("DROP", "VARIABLE", MatchAny))
+ COMPLETE_WITH("CASCADE", "RESTRICT");
+
/* EXECUTE */
else if (Matches("EXECUTE"))
COMPLETE_WITH_QUERY(Query_for_list_of_prepared_statements);
@@ -4457,7 +4481,9 @@ match_previous_words(int pattern_id,
* objects supported.
*/
if (HeadMatches("ALTER", "DEFAULT", "PRIVILEGES"))
- COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS", "LARGE OBJECTS");
+ COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES",
+ "ROUTINES", "TYPES", "SCHEMAS", "LARGE OBJECTS",
+ "VARIABLES");
else
COMPLETE_WITH_SCHEMA_QUERY_PLUS(Query_for_list_of_grantables,
"ALL FUNCTIONS IN SCHEMA",
@@ -4465,6 +4491,7 @@ match_previous_words(int pattern_id,
"ALL ROUTINES IN SCHEMA",
"ALL SEQUENCES IN SCHEMA",
"ALL TABLES IN SCHEMA",
+ "ALL VARIABLES IN SCHEMA",
"DATABASE",
"DOMAIN",
"FOREIGN DATA WRAPPER",
@@ -4479,7 +4506,8 @@ match_previous_words(int pattern_id,
"SEQUENCE",
"TABLE",
"TABLESPACE",
- "TYPE");
+ "TYPE",
+ "VARIABLE");
}
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "ALL") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "ALL"))
@@ -4487,7 +4515,8 @@ match_previous_words(int pattern_id,
"PROCEDURES IN SCHEMA",
"ROUTINES IN SCHEMA",
"SEQUENCES IN SCHEMA",
- "TABLES IN SCHEMA");
+ "TABLES IN SCHEMA",
+ "VARIABLES IN SCHEMA");
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "FOREIGN") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "FOREIGN"))
COMPLETE_WITH("DATA WRAPPER", "SERVER");
@@ -4523,6 +4552,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_tablespaces);
else if (TailMatches("TYPE"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
+ else if (TailMatches("VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatches("GRANT", MatchAny, MatchAny, MatchAny))
COMPLETE_WITH("TO");
else
@@ -4825,7 +4856,7 @@ match_previous_words(int pattern_id,
/* PREPARE xx AS */
else if (Matches("PREPARE", MatchAny, "AS"))
- COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM");
+ COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM", "LET");
/*
* PREPARE TRANSACTION is missing on purpose. It's intended for transaction
@@ -5314,6 +5345,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_roles);
else if (TailMatchesCS("\\dv*"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_views);
+ else if (TailMatchesCS("\\dV*"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatchesCS("\\dx*"))
COMPLETE_WITH_QUERY(Query_for_list_of_extensions);
else if (TailMatchesCS("\\dX*"))
diff --git a/src/include/catalog/Makefile b/src/include/catalog/Makefile
index 2bbc7805fe3..f98760de635 100644
--- a/src/include/catalog/Makefile
+++ b/src/include/catalog/Makefile
@@ -81,7 +81,8 @@ CATALOG_HEADERS := \
pg_publication_namespace.h \
pg_publication_rel.h \
pg_subscription.h \
- pg_subscription_rel.h
+ pg_subscription_rel.h \
+ pg_variable.h
GENERATED_HEADERS := $(CATALOG_HEADERS:%.h=%_d.h)
diff --git a/src/include/catalog/meson.build b/src/include/catalog/meson.build
index ec1cf467f6f..81398efa7c9 100644
--- a/src/include/catalog/meson.build
+++ b/src/include/catalog/meson.build
@@ -69,6 +69,7 @@ catalog_headers = [
'pg_publication_rel.h',
'pg_subscription.h',
'pg_subscription_rel.h',
+ 'pg_variable.h',
]
# The .dat files we need can just be listed alphabetically.
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index 8c7ccc69a3c..bdac0c13bec 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -97,6 +97,8 @@ extern Oid TypenameGetTypid(const char *typname);
extern Oid TypenameGetTypidExtended(const char *typname, bool temp_ok);
extern bool TypeIsVisible(Oid typid);
+extern bool VariableIsVisible(Oid varid);
+
extern FuncCandidateList FuncnameGetCandidates(List *names,
int nargs, List *argnames,
bool expand_variadic,
@@ -169,6 +171,10 @@ extern SearchPathMatcher *GetSearchPathMatcher(MemoryContext context);
extern SearchPathMatcher *CopySearchPathMatcher(SearchPathMatcher *path);
extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
+extern List *NamesFromList(List *names);
+extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
+extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
extern Oid FindDefaultConversionProc(int32 for_encoding, int32 to_encoding);
diff --git a/src/include/catalog/pg_default_acl.h b/src/include/catalog/pg_default_acl.h
index ce6e5098eaf..087d35b943d 100644
--- a/src/include/catalog/pg_default_acl.h
+++ b/src/include/catalog/pg_default_acl.h
@@ -69,6 +69,7 @@ MAKE_SYSCACHE(DEFACLROLENSPOBJ, pg_default_acl_role_nsp_obj_index, 8);
#define DEFACLOBJ_TYPE 'T' /* type */
#define DEFACLOBJ_NAMESPACE 'n' /* namespace */
#define DEFACLOBJ_LARGEOBJECT 'L' /* large object */
+#define DEFACLOBJ_VARIABLE 'V' /* variable */
#endif /* EXPOSE_TO_CLIENT_CODE */
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 5d5be8ba4e1..e27a127ba59 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5466,6 +5466,26 @@
prorettype => 'bool', proargtypes => 'oid oid text',
prosrc => 'has_largeobject_privilege_id_id' },
+{ oid => '9613', descr => 'user privilege on session variable by username, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name text text',
+ prosrc => 'has_session_variable_privilege_name_name' },
+{ oid => '9614', descr => 'user privilege on session variable by username, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name oid text', prosrc => 'has_session_variable_privilege_name_id' },
+{ oid => '9615', descr => 'user privilege on session variable by user oid, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text text', prosrc => 'has_session_variable_privilege_id_name' },
+{ oid => '9616', descr => 'user privilege on session variable by user oid, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid oid text', prosrc => 'has_session_variable_privilege_id_id' },
+{ oid => '9617', descr => 'current user privilege on session variable by seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'text text', prosrc => 'has_session_variable_privilege_name' },
+{ oid => '9618', descr => 'current user privilege on session variable by seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text', prosrc => 'has_session_variable_privilege_id' },
+
{ oid => '3355', descr => 'I/O',
proname => 'pg_ndistinct_in', prorettype => 'pg_ndistinct',
proargtypes => 'cstring', prosrc => 'pg_ndistinct_in' },
@@ -6676,6 +6696,9 @@
proname => 'pg_collation_is_visible', procost => '10', provolatile => 's',
prorettype => 'bool', proargtypes => 'oid',
prosrc => 'pg_collation_is_visible' },
+{ oid => '9999', descr => 'is session variable visible in search path?',
+ proname => 'pg_variable_is_visible', procost => '10', provolatile => 's',
+ prorettype => 'bool', proargtypes => 'oid', prosrc => 'pg_variable_is_visible' },
{ oid => '2854', descr => 'get OID of current session\'s temp schema, if any',
proname => 'pg_my_temp_schema', provolatile => 's', proparallel => 'r',
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
new file mode 100644
index 00000000000..3d3c6eb24b5
--- /dev/null
+++ b/src/include/catalog/pg_variable.h
@@ -0,0 +1,81 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.h
+ * definition of session variables system catalog (pg_variables)
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/catalog/pg_variable.h
+ *
+ * NOTES
+ * The Catalog.pm module reads this file and derives schema
+ * information.
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_VARIABLE_H
+#define PG_VARIABLE_H
+
+#include "catalog/genbki.h"
+#include "catalog/objectaddress.h"
+#include "catalog/pg_variable_d.h"
+#include "utils/acl.h"
+
+/* ----------------
+ * pg_variable definition. cpp turns this into
+ * typedef struct FormData_pg_variable
+ * ----------------
+ */
+CATALOG(pg_variable,9222,VariableRelationId)
+{
+ Oid oid; /* oid */
+
+ /* OID of entry in pg_type for variable's type */
+ Oid vartype BKI_LOOKUP(pg_type);
+
+ /* variable name */
+ NameData varname;
+
+ /* OID of namespace containing variable class */
+ Oid varnamespace BKI_LOOKUP(pg_namespace);
+
+ /* variable owner */
+ Oid varowner BKI_LOOKUP(pg_authid);
+
+ /* typmod for variable's type */
+ int32 vartypmod BKI_DEFAULT(-1);
+
+ /* variable collation */
+ Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation);
+
+
+#ifdef CATALOG_VARLEN /* variable-length fields start here */
+
+ /* access permissions */
+ aclitem varacl[1] BKI_DEFAULT(_null_);
+
+#endif
+} FormData_pg_variable;
+
+/* ----------------
+ * Form_pg_variable corresponds to a pointer to a tuple with
+ * the format of the pg_variable relation.
+ * ----------------
+ */
+typedef FormData_pg_variable *Form_pg_variable;
+
+DECLARE_TOAST(pg_variable, 9223, 9224);
+
+DECLARE_UNIQUE_INDEX_PKEY(pg_variable_oid_index, 9225, VariableOidIndexId, pg_variable, btree(oid oid_ops));
+DECLARE_UNIQUE_INDEX(pg_variable_varname_nsp_index, 9226, VariableNameNspIndexId, pg_variable, btree(varname name_ops, varnamespace oid_ops));
+
+extern ObjectAddress CreateVariable(ParseState *pstate,
+ CreateSessionVarStmt *stmt);
+extern void DropVariableById(Oid varid);
+
+MAKE_SYSCACHE(VARIABLENAMENSP, pg_variable_varname_nsp_index, 8);
+MAKE_SYSCACHE(VARIABLEOID, pg_variable_oid_index, 8);
+
+#endif /* PG_VARIABLE_H */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 4610fc61293..ae4b6a3862c 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2365,6 +2365,7 @@ typedef enum ObjectType
OBJECT_TSTEMPLATE,
OBJECT_TYPE,
OBJECT_USER_MAPPING,
+ OBJECT_VARIABLE,
OBJECT_VIEW,
} ObjectType;
@@ -3515,6 +3516,21 @@ typedef struct AlterStatsStmt
bool missing_ok; /* skip error if statistics object is missing */
} AlterStatsStmt;
+
+/* ----------------------
+ * {Create|Alter} VARIABLE Statement
+ * ----------------------
+ */
+typedef struct CreateSessionVarStmt
+{
+ NodeTag type;
+ RangeVar *variable; /* the variable to create */
+ TypeName *typeName; /* the type of variable */
+ CollateClause *collClause;
+ bool if_not_exists; /* do nothing if it already exists */
+} CreateSessionVarStmt;
+
+
/* ----------------------
* Create Function Statement
* ----------------------
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index a4af3f717a1..0ea0265de7c 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -486,6 +486,8 @@ PG_KEYWORD("validator", VALIDATOR, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("value", VALUE_P, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("values", VALUES, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("varchar", VARCHAR, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variable", VARIABLE, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variables", VARIABLES, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("variadic", VARIADIC, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("varying", VARYING, UNRESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("verbose", VERBOSE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index d250a714d59..ea86954dded 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -68,6 +68,7 @@ PG_CMDTAG(CMDTAG_ALTER_TRANSFORM, "ALTER TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TRIGGER, "ALTER TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TYPE, "ALTER TYPE", true, true, false)
PG_CMDTAG(CMDTAG_ALTER_USER_MAPPING, "ALTER USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_ALTER_VARIABLE, "ALTER VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_VIEW, "ALTER VIEW", true, false, false)
PG_CMDTAG(CMDTAG_ANALYZE, "ANALYZE", false, false, false)
PG_CMDTAG(CMDTAG_BEGIN, "BEGIN", false, false, false)
@@ -123,6 +124,7 @@ PG_CMDTAG(CMDTAG_CREATE_TRANSFORM, "CREATE TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TRIGGER, "CREATE TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TYPE, "CREATE TYPE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_USER_MAPPING, "CREATE USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_CREATE_VARIABLE, "CREATE VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_VIEW, "CREATE VIEW", true, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE, "DEALLOCATE", false, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE_ALL, "DEALLOCATE ALL", false, false, false)
@@ -175,6 +177,7 @@ PG_CMDTAG(CMDTAG_DROP_TRANSFORM, "DROP TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TRIGGER, "DROP TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TYPE, "DROP TYPE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_USER_MAPPING, "DROP USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_DROP_VARIABLE, "DROP VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_VIEW, "DROP VIEW", true, false, false)
PG_CMDTAG(CMDTAG_EXECUTE, "EXECUTE", false, false, false)
PG_CMDTAG(CMDTAG_EXPLAIN, "EXPLAIN", false, false, false)
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index 01ae5b719fd..5e1a8a82e90 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -169,6 +169,7 @@ typedef struct ArrayType Acl;
#define ACL_ALL_RIGHTS_SCHEMA (ACL_USAGE|ACL_CREATE)
#define ACL_ALL_RIGHTS_TABLESPACE (ACL_CREATE)
#define ACL_ALL_RIGHTS_TYPE (ACL_USAGE)
+#define ACL_ALL_RIGHTS_VARIABLE (ACL_SELECT|ACL_UPDATE)
/* operation codes for pg_*_aclmask */
typedef enum
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index d42380a0d46..967d2ac3522 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -139,6 +139,7 @@ extern char get_func_prokind(Oid funcid);
extern bool get_func_leakproof(Oid funcid);
extern RegProcedure get_func_support(Oid funcid);
extern Oid get_relname_relid(const char *relname, Oid relnamespace);
+extern Oid get_varname_varid(const char *varname, Oid varnamespace);
extern char *get_rel_name(Oid relid);
extern Oid get_rel_namespace(Oid relid);
extern Oid get_rel_type_id(Oid relid);
@@ -211,6 +212,14 @@ extern char *get_publication_name(Oid pubid, bool missing_ok);
extern Oid get_subscription_oid(const char *subname, bool missing_ok);
extern char *get_subscription_name(Oid subid, bool missing_ok);
+extern char *get_session_variable_name(Oid varid);
+extern Oid get_session_variable_namespace(Oid varid);
+extern Oid get_session_variable_type(Oid varid);
+extern void get_session_variable_type_typmod_collid(Oid varid,
+ Oid *typid,
+ int32 *typmod,
+ Oid *collid);
+
#define type_is_array(typid) (get_element_type(typid) != InvalidOid)
/* type_is_array_domain accepts both plain arrays and domains over arrays */
#define type_is_array_domain(typid) (get_base_element_type(typid) != InvalidOid)
diff --git a/src/test/regress/expected/dependency.out b/src/test/regress/expected/dependency.out
index 75a078ada9e..cd8e4412fa9 100644
--- a/src/test/regress/expected/dependency.out
+++ b/src/test/regress/expected/dependency.out
@@ -151,3 +151,20 @@ owner of type deptest_t
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+-- should fail
+DROP DOMAIN vardomain;
+ERROR: cannot drop type vardomain because other objects depend on it
+DETAIL: column c of composite type vartype depends on type vardomain
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP TYPE vartype;
+ERROR: cannot drop type vartype because other objects depend on it
+DETAIL: session variable var1 depends on type vartype
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/expected/oidjoins.out b/src/test/regress/expected/oidjoins.out
index 215eb899be3..d9953321402 100644
--- a/src/test/regress/expected/oidjoins.out
+++ b/src/test/regress/expected/oidjoins.out
@@ -266,3 +266,7 @@ NOTICE: checking pg_subscription {subdbid} => pg_database {oid}
NOTICE: checking pg_subscription {subowner} => pg_authid {oid}
NOTICE: checking pg_subscription_rel {srsubid} => pg_subscription {oid}
NOTICE: checking pg_subscription_rel {srrelid} => pg_class {oid}
+NOTICE: checking pg_variable {vartype} => pg_type {oid}
+NOTICE: checking pg_variable {varnamespace} => pg_namespace {oid}
+NOTICE: checking pg_variable {varowner} => pg_authid {oid}
+NOTICE: checking pg_variable {varcollation} => pg_collation {oid}
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index cf48ae6d0c2..fd6b2a6b8c8 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6023,6 +6023,30 @@ COMMIT;
# final ON_ERROR_ROLLBACK: off
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | |
+(1 row)
+
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | =r/regress_variable_owner |
+(1 row)
+
+DROP VARIABLE var1;
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
-- check describing invalid multipart names
\dA regression.heap
improper qualified name (too many dotted names): regression.heap
@@ -6244,6 +6268,12 @@ cross-database references are not implemented: nonesuch.public.func_deps_stat
improper qualified name (too many dotted names): regression.myevt
\dy nonesuch.myevt
improper qualified name (too many dotted names): nonesuch.myevt
+\dV host.regression.public.var
+improper qualified name (too many dotted names): host.regression.public.var
+\dV regression|mydb.public.var
+cross-database references are not implemented: regression|mydb.public.var
+\dV nonesuch.public.var
+cross-database references are not implemented: nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
List of access methods
@@ -6478,6 +6508,12 @@ List of schemas
------+-------+-------+---------+----------+------
(0 rows)
+\dV "no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
improper qualified name (too many dotted names): "no.such.schema"."no.such.access.method"
@@ -6647,6 +6683,12 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
List of tables
@@ -6780,6 +6822,12 @@ List of text search templates
--------+------+------------+-----------+--------------+-----
(0 rows)
+\dV regression."no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -6827,6 +6875,8 @@ cross-database references are not implemented: "no.such.database"."no.such.schem
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
+cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
CREATE ROLE regress_du_role1;
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
new file mode 100644
index 00000000000..c36660ce6d3
--- /dev/null
+++ b/src/test/regress/expected/session_variables.out
@@ -0,0 +1,433 @@
+CREATE ROLE regress_variable_owner;
+SET log_statement TO ddl;
+-- should be ok
+CREATE VARIABLE var1 AS int;
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+ERROR: session variable cannot be pseudo-type anyelement
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+NOTICE: session variable "var2" does not exist, skipping
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+NOTICE: session variable "var1" already exists, skipping
+-- should fail
+CREATE VARIABLE var1 AS int;
+ERROR: session variable "var1" already exists
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TABLE t1;
+ERROR: cannot drop table t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+ERROR: cannot alter table "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TABLE t1;
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TYPE t1;
+ERROR: cannot drop type t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+ERROR: cannot alter type "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TYPE t1;
+SET log_statement TO default;
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+CREATE VARIABLE var1 AS testvar_domain;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter domain "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS testvar_type;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter type "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+NOTICE: NORMAL: orig=t normal=f istemp=f type=session variable identity=public.var1 name={public,var1} args={}
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+ obj_description
+-----------------------
+ some variable comment
+(1 row)
+
+DROP VARIABLE var1;
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+ varname | descr | type | object_names | object_args | ident
+---------------+-----------------------------------------+------------------+--------------------------+-------------+--------------------------------------------------------------------
+ svartest_var1 | session variable vartest1.svartest_var1 | session variable | {vartest1,svartest_var1} | {} | ("session variable",vartest1,svartest_var1,vartest1.svartest_var1)
+ svartest_var1 | session variable vartest2.svartest_var1 | session variable | {vartest2,svartest_var1} | {} | ("session variable",vartest2,svartest_var1,vartest2.svartest_var1)
+(2 rows)
+
+DROP SCHEMA vartest1 CASCADE;
+NOTICE: drop cascades to session variable vartest1.svartest_var1
+DROP SCHEMA vartest2 CASCADE;
+NOTICE: drop cascades to session variable vartest2.svartest_var1
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE ROLE regress_variable_reader;
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+DROP VARIABLE public.varxx;
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE public.var1 AS int;
+SET search_path TO public;
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+SET ROLE TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+--
+-- end of function has_session_variable_privilege tests.
+--
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+DROP VARIABLE public.var1;
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+DROP ROLE regress_variable_owner;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 0a35f2f8f6a..66e5f9f56bd 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -111,7 +111,7 @@ test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath sqljson
# NB: temp.sql does reconnects which transiently use 2 connections,
# so keep this parallel group to at most 19 tests
# ----------
-test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml
+test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml session_variables
# ----------
# Another group of parallel tests
diff --git a/src/test/regress/sql/dependency.sql b/src/test/regress/sql/dependency.sql
index 8d74ed7122c..6c18b7f840a 100644
--- a/src/test/regress/sql/dependency.sql
+++ b/src/test/regress/sql/dependency.sql
@@ -114,3 +114,17 @@ DROP USER regress_dep_user2;
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+
+-- should fail
+DROP DOMAIN vardomain;
+DROP TYPE vartype;
+
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index 1a8a83462f0..b567ee1eee2 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -1643,6 +1643,19 @@ COMMIT;
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+DROP VARIABLE var1;
+
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
+
-- check describing invalid multipart names
\dA regression.heap
\dA nonesuch.heap
@@ -1754,6 +1767,9 @@ DROP FUNCTION psql_error;
\dX nonesuch.public.func_deps_stat
\dy regression.myevt
\dy nonesuch.myevt
+\dV host.regression.public.var
+\dV regression|mydb.public.var
+\dV nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
@@ -1795,6 +1811,8 @@ DROP FUNCTION psql_error;
\dx "no.such.installed.extension"
\dX "no.such.extended.statistics"
\dy "no.such.event.trigger"
+\dV "no.such.variable"
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
@@ -1835,6 +1853,7 @@ DROP FUNCTION psql_error;
\dx "no.such.schema"."no.such.installed.extension"
\dX "no.such.schema"."no.such.extended.statistics"
\dy "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
@@ -1859,6 +1878,7 @@ DROP FUNCTION psql_error;
\dP regression."no.such.schema"."no.such.partitioned.relation"
\dT regression."no.such.schema"."no.such.data.type"
\dX regression."no.such.schema"."no.such.extended.statistics"
+\dV regression."no.such.schema"."no.such.variable"
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -1884,6 +1904,7 @@ DROP FUNCTION psql_error;
\dP "no.such.database"."no.such.schema"."no.such.partitioned.relation"
\dT "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
new file mode 100644
index 00000000000..eeb0f94ca3c
--- /dev/null
+++ b/src/test/regress/sql/session_variables.sql
@@ -0,0 +1,297 @@
+CREATE ROLE regress_variable_owner;
+
+SET log_statement TO ddl;
+
+-- should be ok
+CREATE VARIABLE var1 AS int;
+
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+
+-- should fail
+CREATE VARIABLE var1 AS int;
+
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TABLE t1;
+
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TABLE t1;
+
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TYPE t1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+SET log_statement TO default;
+
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+
+CREATE VARIABLE var1 AS testvar_domain;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+CREATE VARIABLE var1 AS testvar_type;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+
+DROP VARIABLE var1;
+
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+
+DROP SCHEMA vartest1 CASCADE;
+DROP SCHEMA vartest2 CASCADE;
+
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+
+CREATE ROLE regress_variable_reader;
+
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+
+DROP VARIABLE public.varxx;
+
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE public.var1 AS int;
+
+SET search_path TO public;
+
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+
+SET ROLE TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+--
+-- end of function has_session_variable_privilege tests.
+--
+
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+
+DROP VARIABLE public.var1;
+
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+
+DROP ROLE regress_variable_owner;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 0c81d03950d..f18ace1be15 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -559,6 +559,7 @@ CreateRoleStmt
CreateSchemaStmt
CreateSchemaStmtContext
CreateSeqStmt
+CreateSessionVarStmt
CreateStatsStmt
CreateStmt
CreateStmtContext
@@ -901,6 +902,7 @@ FormData_pg_ts_parser
FormData_pg_ts_template
FormData_pg_type
FormData_pg_user_mapping
+FormData_pg_variable
FormExtraData_pg_attribute
Form_pg_aggregate
Form_pg_am
@@ -960,6 +962,7 @@ Form_pg_ts_parser
Form_pg_ts_template
Form_pg_type
Form_pg_user_mapping
+Form_pg_variable
FormatNode
FreeBlockNumberArray
FreeListData
@@ -3179,6 +3182,7 @@ VarString
VarStringSortSupport
Variable
VariableAssignHook
+VariableInfo
VariableSetKind
VariableSetStmt
VariableShowStmt
--
2.49.0
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-05-15 06:48 ` Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Pavel Stehule @ 2025-05-15 06:48 UTC (permalink / raw)
To: Marcos Pegoraro <[email protected]>; +Cc: jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
Hi
fresh rebase
Regards
Pavel
Attachments:
[text/x-patch] v20250515-0008-variable-fence-syntax-support-and-variable-fence-usa.patch (19.5K, ../../CAFj8pRCEjG005L=1vGbir-odYdcYxByOAeFVJ_K9eRcRF=MbNQ@mail.gmail.com/3-v20250515-0008-variable-fence-syntax-support-and-variable-fence-usa.patch)
download | inline diff:
From 8f8ea17366a5659b8e82347986839f64b26312c6 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 19 Nov 2024 08:14:53 +0100
Subject: [PATCH 08/21] variable fence syntax support and variable fence usage
guard support
this patch introduces a concept of variable fence - syntax for variable
reference `VARIABLE(varname)` that is not in collision with column reference.
When variable fence usage guard warning is active, then usage variable
without variable fence in the case, where there can be column references,
the the warning is raised.
initial implementation of variable fence
---
doc/src/sgml/config.sgml | 65 ++++++++++++++++
doc/src/sgml/ddl.sgml | 15 ++++
src/backend/nodes/nodeFuncs.c | 6 ++
src/backend/parser/gram.y | 28 ++++++-
src/backend/parser/parse_expr.c | 74 ++++++++++++++++++-
src/backend/parser/parse_target.c | 7 ++
src/backend/utils/adt/ruleutils.c | 12 ++-
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/nodes/parsenodes.h | 10 +++
src/include/nodes/primnodes.h | 2 +
src/include/parser/parse_expr.h | 1 +
.../regress/expected/session_variables.out | 59 +++++++++++++++
src/test/regress/sql/session_variables.sql | 41 ++++++++++
14 files changed, 323 insertions(+), 7 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index e34da8ab9d6..be4b76ebe31 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11434,6 +11434,71 @@ DETAIL: Session variables can be shadowed by columns, routine's variables and r
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-use-fence-warning-guard" xreflabel="session_variables_use_fence_warning_guard">
+ <term><varname>session_variables_use_fence_warning_guard</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_use_fence_warning_guard</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when a session variable identifier is used
+ inside a query without variable fence. The default is <literal>off</literal>.
+ The warning is raised only when variable is used in places, where an
+ collisions with column names is possible.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE b int;
+LET b = 100;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_use_fence_warning_guard TO on;
+SELECT a, b FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "b" is not used inside variable fence
+LINE 1: SELECT a, b FROM foo;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+
+<programlisting>
+SELECT a, VARIABLE(b) FROM foo;
+</programlisting>
+
+<screen>
+ a | b
+----+-----
+ 10 | 100
+(1 row)
+</screen>
+ </para>
+
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. Unless another collision resolution technique is used
+ (dedicated schema or using prefixes like <literal>_</literal>),
+ the use of variable fence syntax is strongly recommended, and this
+ warning should be enabled.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 3a3f6be79f2..2a25d5ce758 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5457,6 +5457,21 @@ SELECT name FROM foo;
<literal>schema.variable</literal>. It is strongly recommended to rename
shadowed variables or use qualified names always.
</para>
+
+ <para><firstterm>Variable fence</firstterm> is special syntax for session
+ variable identifier. Only name or qualified name can be used inside the
+ variable fence, and this name is used as only session variable identifier.
+<programlisting>
+SELECT VARIABLE(current_user_id);
+</programlisting>
+ </para>
+
+ <para>
+ When there is a risk of possible collisions between variable identifiers
+ and column names, then using variable fence syntax can be recommended.
+ Usage session variable without variable fence can be detected by
+ warning <xref linkend="guc-session-variables-use-fence-warning-guard"/>.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d8fc3d9fa69..575365eefcd 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -1673,6 +1673,9 @@ exprLocation(const Node *expr)
case T_ParamRef:
loc = ((const ParamRef *) expr)->location;
break;
+ case T_VariableFence:
+ loc = ((const VariableFence *) expr)->location;
+ break;
case T_A_Const:
loc = ((const A_Const *) expr)->location;
break;
@@ -4715,6 +4718,9 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_VariableFence:
+ /* we assume the fields contain nothing interesting */
+ break;
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 1074d62b7db..72bb33aed61 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -525,7 +525,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <node> def_arg columnElem where_clause where_or_current_clause
a_expr b_expr c_expr AexprConst indirection_el opt_slice_bound
columnref in_expr having_clause func_table xmltable array_expr
- OptWhereClause operator_def_arg
+ OptWhereClause operator_def_arg variable_fence
%type <list> opt_column_and_period_list
%type <list> rowsfrom_item rowsfrom_list opt_col_def_list
%type <boolean> opt_ordinality opt_without_overlaps
@@ -882,7 +882,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
*/
%nonassoc UNBOUNDED NESTED /* ideally would have same precedence as IDENT */
%nonassoc IDENT PARTITION RANGE ROWS GROUPS PRECEDING FOLLOWING CUBE ROLLUP
- SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH
+ SET KEYS OBJECT_P SCALAR VALUE_P WITH WITHOUT PATH VARIABLE
%left Op OPERATOR /* multi-character ops and user-defined operators */
%left '+' '-'
%left '*' '/' '%'
@@ -15691,6 +15691,19 @@ c_expr: columnref { $$ = $1; }
else
$$ = $2;
}
+ | variable_fence opt_indirection
+ {
+ if ($2)
+ {
+ A_Indirection *n = makeNode(A_Indirection);
+
+ n->arg = (Node *) $1;
+ n->indirection = check_indirection($2, yyscanner);
+ $$ = (Node *) n;
+ }
+ else
+ $$ = $1;
+ }
| case_expr
{ $$ = $1; }
| func_expr
@@ -17077,6 +17090,17 @@ case_arg: a_expr { $$ = $1; }
| /*EMPTY*/ { $$ = NULL; }
;
+variable_fence:
+ VARIABLE '(' any_name ')'
+ {
+ VariableFence *vf = makeNode(VariableFence);
+
+ vf->varname = $3;
+ vf->location = @3;
+ $$ = (Node *) vf;
+ }
+ ;
+
columnref: ColId
{
$$ = makeColumnRef($1, NIL, @1, yyscanner);
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index b10e1bca308..fba2eb2de84 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -46,6 +46,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
bool session_variables_ambiguity_warning = false;
+bool session_variables_use_fence_warning_guard = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -81,6 +82,7 @@ static Node *transformWholeRowRef(ParseState *pstate,
static Node *transformIndirection(ParseState *pstate, A_Indirection *ind);
static Node *transformTypeCast(ParseState *pstate, TypeCast *tc);
static Node *transformCollateClause(ParseState *pstate, CollateClause *c);
+static Node *transformVariableFence(ParseState *pstate, VariableFence *vf);
static Node *transformJsonObjectConstructor(ParseState *pstate,
JsonObjectConstructor *ctor);
static Node *transformJsonArrayConstructor(ParseState *pstate,
@@ -112,7 +114,7 @@ static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
static Node *makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location);
+ char *attrname, bool fenced, int location);
/*
@@ -377,6 +379,10 @@ transformExprRecurse(ParseState *pstate, Node *expr)
result = transformJsonFuncExpr(pstate, (JsonFuncExpr *) expr);
break;
+ case T_VariableFence:
+ result = transformVariableFence(pstate, (VariableFence *) expr);
+ break;
+
default:
/* should not reach here */
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(expr));
@@ -1028,7 +1034,20 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
node = makeParamSessionVariable(pstate,
varid, typid, typmod, collid,
- attrname, cref->location);
+ attrname, false, cref->location);
+
+ /*
+ * The variable is not inside variable's fence, so raise warning
+ * when variable fence guard is active and the query has FROM
+ * clause.
+ */
+ if (session_variables_use_fence_warning_guard && pstate->p_rtable)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is not used inside variable fence",
+ NameListToString(cref->fields)),
+ errdetail("The collision of session variable' names and column names is possible."),
+ parser_errposition(pstate, cref->location)));
}
}
}
@@ -1071,7 +1090,7 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
static Node *
makeParamSessionVariable(ParseState *pstate,
Oid varid, Oid typid, int32 typmod, Oid collid,
- char *attrname, int location)
+ char *attrname, bool fenced, int location)
{
Param *param;
@@ -1079,6 +1098,7 @@ makeParamSessionVariable(ParseState *pstate,
param->paramkind = PARAM_VARIABLE;
param->paramvarid = varid;
+ param->paramvarfenced = fenced;
param->paramtype = typid;
param->paramtypmod = typmod;
param->paramcollid = collid;
@@ -1157,6 +1177,54 @@ transformParamRef(ParseState *pstate, ParamRef *pref)
return result;
}
+static Node *
+transformVariableFence(ParseState *pstate, VariableFence *vf)
+{
+ Node *result;
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* VariableFence can be used only in context when variables are supported */
+ if (!expr_kind_allows_session_variables(pstate->p_expr_kind))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable reference is not supported here"),
+ parser_errposition(pstate, vf->location)));
+
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(vf->varname, &attrname, ¬_unique, false);
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ result = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, true, vf->location);
+ }
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(vf->varname)),
+ parser_errposition(pstate, vf->location)));
+
+ return result;
+}
+
/* Test whether an a_expr is a plain NULL constant or not */
static bool
exprIsNullConstant(Node *arg)
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 4aba0d9d4d5..cf01bff65a9 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -2034,6 +2034,13 @@ FigureColnameInternal(Node *node, char **name)
(int) ((JsonFuncExpr *) node)->op);
}
break;
+ case T_VariableFence:
+ {
+ /* return last field name */
+ *name = strVal(llast(((VariableFence *) node)->varname));
+ return 2;
+ }
+ break;
default:
break;
}
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index f23f511cd56..c347991d16a 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8734,8 +8734,16 @@ get_parameter(Param *param, deparse_context *context)
/* translate paramvarid to session variable name */
if (param->paramkind == PARAM_VARIABLE)
{
- appendStringInfo(context->buf, "%s",
- generate_session_variable_name(param->paramvarid));
+ if (param->paramvarfenced)
+ {
+ appendStringInfo(context->buf, "VARIABLE(%s)",
+ generate_session_variable_name(param->paramvarid));
+ }
+ else
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ }
return;
}
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 31d70785b14..c8c28d769bb 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1653,6 +1653,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_use_fence_warning_guard", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when variable is not used inside variable fence."),
+ NULL
+ },
+ &session_variables_use_fence_warning_guard,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 66c6577eceb..3113e243bce 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -765,6 +765,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_deferrable = off
#session_replication_role = 'origin'
#session_variables_ambiguity_warning = off
+#session_variables_use_fence_warning_guard = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 321235c6491..f73ec20d665 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -321,6 +321,16 @@ typedef struct ParamRef
ParseLoc location; /* token location, or -1 if unknown */
} ParamRef;
+/*
+ * VariableFence - ensure so fields will be interpretted as a variable
+ */
+typedef struct VariableFence
+{
+ NodeTag type;
+ List *varname; /* variable name (String nodes) */
+ ParseLoc location; /* token location, or -1 if unknown */
+} VariableFence;
+
/*
* A_Expr - infix, prefix, and postfix expressions
*/
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 3cc2f019abb..98bca694480 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -411,6 +411,8 @@ typedef struct Param
* param is used just for execution of UPDATE operation.
*/
bool parambasenode;
+ /* true when variable is used inside an fence */
+ bool paramvarfenced;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index d2209070181..5bde43758d1 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -18,6 +18,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
extern PGDLLIMPORT bool session_variables_ambiguity_warning;
+extern PGDLLIMPORT bool session_variables_use_fence_warning_guard;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 7c350ad5ef9..9ac08a14e0b 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1969,3 +1969,62 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
NOTICE: drop cascades to session variable xxtab.avar
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+CREATE SCHEMA testvar;
+SET search_path TO 'testvar';
+CREATE VARIABLE a AS int;
+LET a = 10;
+CREATE TABLE test_table(a int, b int);
+INSERT INTO test_table VALUES(20, 20);
+-- no warning
+SELECT a;
+ a
+----
+ 10
+(1 row)
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a | b
+----+----
+ 20 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a) FROM test_table;
+ a
+----
+ 10
+(1 row)
+
+ALTER TABLE test_table DROP COLUMN a;
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+WARNING: session variable "a" is not used inside variable fence
+LINE 1: SELECT a, b FROM test_table;
+ ^
+DETAIL: The collision of session variable' names and column names is possible.
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+DROP SCHEMA testvar;
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 68be415bf26..c5420183d94 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1360,3 +1360,44 @@ SET session_variables_ambiguity_warning TO off;
DROP TABLE public.xxtab;
DROP SCHEMA xxtab CASCADE;
+
+-- test session_variables_use_fence_warning_guard
+SET session_variables_ambiguity_warning TO on;
+SET session_variables_use_fence_warning_guard TO on;
+
+CREATE SCHEMA testvar;
+
+SET search_path TO 'testvar';
+
+CREATE VARIABLE a AS int;
+LET a = 10;
+
+CREATE TABLE test_table(a int, b int);
+
+INSERT INTO test_table VALUES(20, 20);
+
+-- no warning
+SELECT a;
+
+-- warning variable is shadowed
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a) FROM test_table;
+
+ALTER TABLE test_table DROP COLUMN a;
+
+-- warning - variable fence is not used
+SELECT a, b FROM test_table;
+
+-- no warning
+SELECT variable(a), b FROM test_table;
+
+DROP VARIABLE a;
+DROP TABLE test_table;
+
+DROP SCHEMA testvar;
+
+SET session_variables_ambiguity_warning TO DEFAULT;
+SET session_variables_use_fence_warning_guard TO DEFAULT;
+SET search_path TO DEFAULT;
--
2.49.0
[text/x-patch] v20250515-0004-DISCARD-VARIABLES.patch (9.6K, ../../CAFj8pRCEjG005L=1vGbir-odYdcYxByOAeFVJ_K9eRcRF=MbNQ@mail.gmail.com/4-v20250515-0004-DISCARD-VARIABLES.patch)
download | inline diff:
From ad9a17c414a2e817a9737f75e91d7cae1394b02a Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Sun, 28 Jan 2024 20:54:20 +0100
Subject: [PATCH 04/21] DISCARD VARIABLES
Implementation of DISCARD VARIABLES commands by removing hash table with session variables
and resetting related memory context.
---
doc/src/sgml/ref/discard.sgml | 13 +++-
src/backend/commands/discard.c | 6 ++
src/backend/commands/session_variable.c | 28 ++++++++-
src/backend/parser/gram.y | 6 ++
src/backend/tcop/utility.c | 3 +
src/bin/psql/tab-complete.in.c | 2 +-
src/include/commands/session_variable.h | 2 +
src/include/nodes/parsenodes.h | 1 +
src/include/tcop/cmdtaglist.h | 1 +
.../regress/expected/session_variables.out | 63 +++++++++++++++++++
src/test/regress/sql/session_variables.sql | 36 +++++++++++
11 files changed, 158 insertions(+), 3 deletions(-)
diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
index bf44c523cac..61b967f9c9b 100644
--- a/doc/src/sgml/ref/discard.sgml
+++ b/doc/src/sgml/ref/discard.sgml
@@ -21,7 +21,7 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
-DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
+DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP | VARIABLES }
</synopsis>
</refsynopsisdiv>
@@ -66,6 +66,16 @@ DISCARD { ALL | PLANS | SEQUENCES | TEMPORARY | TEMP }
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>VARIABLES</literal></term>
+ <listitem>
+ <para>
+ Resets the value of all session variables. If a variable
+ is later reused, it is re-initialized to <literal>NULL</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><literal>TEMPORARY</literal> or <literal>TEMP</literal></term>
<listitem>
@@ -93,6 +103,7 @@ SELECT pg_advisory_unlock_all();
DISCARD PLANS;
DISCARD TEMP;
DISCARD SEQUENCES;
+DISCARD VARIABLES;
</programlisting></para>
</listitem>
</varlistentry>
diff --git a/src/backend/commands/discard.c b/src/backend/commands/discard.c
index 81339a75a52..5904a6c4917 100644
--- a/src/backend/commands/discard.c
+++ b/src/backend/commands/discard.c
@@ -18,6 +18,7 @@
#include "commands/async.h"
#include "commands/discard.h"
#include "commands/prepare.h"
+#include "commands/session_variable.h"
#include "commands/sequence.h"
#include "utils/guc.h"
#include "utils/portal.h"
@@ -48,6 +49,10 @@ DiscardCommand(DiscardStmt *stmt, bool isTopLevel)
ResetTempTableNamespace();
break;
+ case DISCARD_VARIABLES:
+ ResetSessionVariables();
+ break;
+
default:
elog(ERROR, "unrecognized DISCARD target: %d", stmt->target);
}
@@ -75,4 +80,5 @@ DiscardAll(bool isTopLevel)
ResetPlanCache();
ResetTempTableNamespace();
ResetSequenceCaches();
+ ResetSessionVariables();
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index fa16f47072e..e1c86966998 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -94,7 +94,13 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
- Assert(sessionvars);
+ /*
+ * There is no guarantee of session variables being initialized, even when
+ * receiving an invalidation callback, as DISCARD [ ALL | VARIABLES ]
+ * destroys the hash table entirely.
+ */
+ if (!sessionvars)
+ return;
/*
* If the hashvalue is not specified, we have to recheck all currently
@@ -619,3 +625,23 @@ pg_session_variables(PG_FUNCTION_ARGS)
return (Datum) 0;
}
+
+/*
+ * Fast drop of the complete content of the session variables hash table, and
+ * cleanup of any list that wouldn't be relevant anymore.
+ * This is used by the DISCARD VARIABLES (and DISCARD ALL) command.
+ */
+void
+ResetSessionVariables(void)
+{
+ /* destroy hash table and reset related memory context */
+ if (sessionvars)
+ {
+ hash_destroy(sessionvars);
+ sessionvars = NULL;
+ }
+
+ /* release memory allocated by session variables */
+ if (SVariableMemoryContext != NULL)
+ MemoryContextReset(SVariableMemoryContext);
+}
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 99fac3411da..1074d62b7db 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -2084,7 +2084,13 @@ DiscardStmt:
n->target = DISCARD_SEQUENCES;
$$ = (Node *) n;
}
+ | DISCARD VARIABLES
+ {
+ DiscardStmt *n = makeNode(DiscardStmt);
+ n->target = DISCARD_VARIABLES;
+ $$ = (Node *) n;
+ }
;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 7a508a3644f..6e4d2310f5c 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -2962,6 +2962,9 @@ CreateCommandTag(Node *parsetree)
case DISCARD_SEQUENCES:
tag = CMDTAG_DISCARD_SEQUENCES;
break;
+ case DISCARD_VARIABLES:
+ tag = CMDTAG_DISCARD_VARIABLES;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 39d1b6aa610..06cbac40ca0 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -4152,7 +4152,7 @@ match_previous_words(int pattern_id,
/* DISCARD */
else if (Matches("DISCARD"))
- COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP");
+ COMPLETE_WITH("ALL", "PLANS", "SEQUENCES", "TEMP", "VARIABLES");
/* DO */
else if (Matches("DO"))
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index 2391b9ad443..a8ca43c87af 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -27,4 +27,6 @@ extern Datum GetSessionVariable(Oid varid, bool *isNull);
extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
QueryEnvironment *queryEnv, QueryCompletion *qc);
+extern void ResetSessionVariables(void);
+
#endif
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 8f874a08d29..321235c6491 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -4056,6 +4056,7 @@ typedef enum DiscardMode
DISCARD_PLANS,
DISCARD_SEQUENCES,
DISCARD_TEMP,
+ DISCARD_VARIABLES,
} DiscardMode;
typedef struct DiscardStmt
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index 22082c30008..bef0ac25331 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -135,6 +135,7 @@ PG_CMDTAG(CMDTAG_DISCARD_ALL, "DISCARD ALL", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_PLANS, "DISCARD PLANS", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_SEQUENCES, "DISCARD SEQUENCES", false, false, false)
PG_CMDTAG(CMDTAG_DISCARD_TEMP, "DISCARD TEMP", false, false, false)
+PG_CMDTAG(CMDTAG_DISCARD_VARIABLES, "DISCARD VARIABLES", false, false, false)
PG_CMDTAG(CMDTAG_DO, "DO", false, false, false)
PG_CMDTAG(CMDTAG_DROP_ACCESS_METHOD, "DROP ACCESS METHOD", true, false, false)
PG_CMDTAG(CMDTAG_DROP_AGGREGATE, "DROP AGGREGATE", true, false, false)
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index f22467186e3..79ac40768f8 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1663,3 +1663,66 @@ DROP VARIABLE :"DBNAME".:"DBNAME".b;
DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+ var1
+-------
+ Hello
+(1 row)
+
+DISCARD ALL;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT var1;
+ var1
+------
+ AHOJ
+(1 row)
+
+DISCARD VARIABLES;
+SELECT var1;
+ var1
+------
+
+(1 row)
+
+DROP VARIABLE var1;
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS varchar;
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
+LET var1 = 'AHOJ';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DISCARD VARIABLES;
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
+ count
+-------
+ 0
+(1 row)
+
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index e72360d5254..2954759aaed 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1178,3 +1178,39 @@ DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
DROP SCHEMA :"DBNAME";
RESET search_path;
+
+-- memory cleaning by DISCARD command
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Hello';
+SELECT var1;
+
+DISCARD ALL;
+SELECT var1;
+
+LET var1 = 'AHOJ';
+SELECT var1;
+
+DISCARD VARIABLES;
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- initial test of debug pg_session_variables function
+-- should be zero now
+DISCARD VARIABLES;
+
+SELECT count(*) FROM pg_session_variables();
+
+CREATE VARIABLE var1 AS varchar;
+
+-- should be zero still
+SELECT count(*) FROM pg_session_variables();
+
+LET var1 = 'AHOJ';
+
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+
+DISCARD VARIABLES;
+
+-- should be zero again
+SELECT count(*) FROM pg_session_variables();
--
2.49.0
[text/x-patch] v20250515-0006-plpgsql-tests.patch (16.9K, ../../CAFj8pRCEjG005L=1vGbir-odYdcYxByOAeFVJ_K9eRcRF=MbNQ@mail.gmail.com/5-v20250515-0006-plpgsql-tests.patch)
download | inline diff:
From 517003cf360f643cfc9a2ed22c0894641038e5ca Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 14:06:06 +0100
Subject: [PATCH 06/21] plpgsql tests
---
src/pl/plpgsql/src/Makefile | 3 +-
.../src/expected/plpgsql_session_variable.out | 382 ++++++++++++++++++
src/pl/plpgsql/src/meson.build | 1 +
.../src/sql/plpgsql_session_variable.sql | 289 +++++++++++++
4 files changed, 674 insertions(+), 1 deletion(-)
create mode 100644 src/pl/plpgsql/src/expected/plpgsql_session_variable.out
create mode 100644 src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
diff --git a/src/pl/plpgsql/src/Makefile b/src/pl/plpgsql/src/Makefile
index 63cb96fae3e..bbcae27d422 100644
--- a/src/pl/plpgsql/src/Makefile
+++ b/src/pl/plpgsql/src/Makefile
@@ -35,7 +35,8 @@ REGRESS_OPTS = --dbname=$(PL_TESTDB)
REGRESS = plpgsql_array plpgsql_cache plpgsql_call plpgsql_control \
plpgsql_copy plpgsql_domain plpgsql_misc \
plpgsql_record plpgsql_simple plpgsql_transaction \
- plpgsql_trap plpgsql_trigger plpgsql_varprops
+ plpgsql_trap plpgsql_trigger plpgsql_varprops \
+ plpgsql_session_variable
# where to find gen_keywordlist.pl and subsidiary files
TOOLSDIR = $(top_srcdir)/src/tools
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
new file mode 100644
index 00000000000..ab779900596
--- /dev/null
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -0,0 +1,382 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+LET plpgsql_sv_var = pi();
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+NOTICE: value of session variable is 3.14159265358979
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+ pi_multiply_2
+------------------
+ 6.28318530717959
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var;
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+END;
+-- execute outside of a transaction
+SELECT writer_func();
+ writer_func
+-------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+ reader_func
+-------------
+
+(1 row)
+
+SELECT updater_func();
+ updater_func
+--------------
+
+(1 row)
+
+SELECT reader_func();
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+ reader_func
+-------------
+
+(1 row)
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+NOTICE: var1 = 10
+NOTICE: var2 = 3.14159265358979
+NOTICE: length of var3 = 10002
+NOTICE: var1 = 110
+NOTICE: var2 = 100000000003.14159265358979
+NOTICE: length of var3 = 20004
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+SELECT test_func();
+NOTICE: {100}
+NOTICE: {-1}
+ test_func
+-----------
+
+(1 row)
+
+DROP FUNCTION test_func();
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+SET ROLE TO regress_var_owner_role;
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_reader_role;
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail
+SELECT var_read_func();
+ERROR: permission denied for session variable plpgsql_sv_var1
+CONTEXT: PL/pgSQL expression "plpgsql_sv_var1"
+PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should be ok
+SELECT var_read_func();
+NOTICE: 10
+ var_read_func
+---------------
+
+(1 row)
+
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_owner_role;
+DROP VARIABLE plpgsql_sv_var1;
+SET ROLE TO DEFAULT;
+SET ROLE TO regress_var_exec_role;
+-- should fail, but not crash
+SELECT var_read_func();
+ERROR: column "plpgsql_sv_var1" does not exist
+LINE 1: plpgsql_sv_var1
+ ^
+QUERY: plpgsql_sv_var1
+CONTEXT: PL/pgSQL function var_read_func() line 3 at RAISE
+SET ROLE TO DEFAULT;
+DROP FUNCTION var_read_func;
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_int(1);
+ inc_var_int
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+ inc_var_int
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+LET plpgsql_sv_var2 = 0.0;
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 1
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 2
+(1 row)
+
+SELECT inc_var_num(1.0);
+ inc_var_num
+-------------
+ 3
+(1 row)
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+ inc_var_num
+-------------
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+ 11
+ 12
+ 13
+(10 rows)
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+NOTICE: variable is 1000
+DROP VARIABLE plpgsql_sv_var1;
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+select ffunc();
+ ffunc
+-------
+ abc
+(1 row)
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+DROP VARIABLE plpgsql_sv_v;
diff --git a/src/pl/plpgsql/src/meson.build b/src/pl/plpgsql/src/meson.build
index 33c49ac25d9..1d01d1c2629 100644
--- a/src/pl/plpgsql/src/meson.build
+++ b/src/pl/plpgsql/src/meson.build
@@ -88,6 +88,7 @@ tests += {
'plpgsql_trap',
'plpgsql_trigger',
'plpgsql_varprops',
+ 'plpgsql_session_variable',
],
},
}
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
new file mode 100644
index 00000000000..a3cc264cf38
--- /dev/null
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -0,0 +1,289 @@
+-- test of session variables
+CREATE VARIABLE plpgsql_sv_var AS numeric;
+
+LET plpgsql_sv_var = pi();
+
+-- passing parameters to DO block
+DO $$
+BEGIN
+ RAISE NOTICE 'value of session variable is %', plpgsql_sv_var;
+END;
+$$;
+
+-- passing output from DO block;
+DO $$
+BEGIN
+ LET plpgsql_sv_var = 2 * pi();
+END
+$$;
+
+SELECT plpgsql_sv_var AS "pi_multiply_2";
+
+DROP VARIABLE plpgsql_sv_var;
+
+-- test access from PL/pgSQL
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+CREATE OR REPLACE FUNCTION writer_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = 10;
+ LET plpgsql_sv_var2 = pi();
+ -- very long value
+ LET plpgsql_sv_var3 = format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION updater_func()
+RETURNS void AS $$
+BEGIN
+ LET plpgsql_sv_var1 = plpgsql_sv_var1 + 100;
+ LET plpgsql_sv_var2 = plpgsql_sv_var2 + 100000000000;
+ -- very long value
+ LET plpgsql_sv_var3 = plpgsql_sv_var3 || format('(%s)', repeat('*', 10000));
+END;
+$$ LANGUAGE plpgsql;
+
+
+CREATE OR REPLACE FUNCTION reader_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE 'var1 = %', plpgsql_sv_var1;
+ RAISE NOTICE 'var2 = %', plpgsql_sv_var2;
+ RAISE NOTICE 'length of var3 = %', length(plpgsql_sv_var3);
+END;
+$$ LANGUAGE plpgsql;
+
+-- execute in a transaction
+BEGIN;
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+END;
+
+-- execute outside of a transaction
+SELECT writer_func();
+SELECT reader_func();
+SELECT updater_func();
+SELECT reader_func();
+
+-- execute inside a PL/pgSQL block
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+-- plan caches should be correctly invalidated
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+CREATE VARIABLE plpgsql_sv_var3 AS varchar;
+
+-- should work again
+DO $$
+BEGIN
+ PERFORM writer_func();
+ PERFORM reader_func();
+ PERFORM updater_func();
+ PERFORM reader_func();
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2, plpgsql_sv_var3;
+
+DROP FUNCTION writer_func;
+DROP FUNCTION reader_func;
+DROP FUNCTION updater_func;
+
+-- another check of correct plan cache invalidation
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+CREATE OR REPLACE FUNCTION test_func()
+RETURNS void AS $$
+DECLARE v int[] DEFAULT '{}';
+BEGIN
+ LET plpgsql_sv_var1 = 1;
+ v[plpgsql_sv_var1] = 100;
+ RAISE NOTICE '%', v;
+ LET plpgsql_sv_var2 = v;
+ LET plpgsql_sv_var2[plpgsql_sv_var1] = -1;
+ RAISE NOTICE '%', plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+CREATE VARIABLE plpgsql_sv_var2 AS int[];
+
+SELECT test_func();
+
+DROP FUNCTION test_func();
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+-- check secure access
+CREATE ROLE regress_var_owner_role;
+CREATE ROLE regress_var_reader_role;
+CREATE ROLE regress_var_exec_role;
+
+GRANT ALL ON SCHEMA public TO regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+SET ROLE TO regress_var_owner_role;
+
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+LET plpgsql_sv_var1 = 10;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_reader_role;
+
+CREATE OR REPLACE FUNCTION var_read_func()
+RETURNS void AS $$
+BEGIN
+ RAISE NOTICE '%', plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql SECURITY DEFINER;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+GRANT SELECT ON VARIABLE plpgsql_sv_var1 TO regress_var_reader_role;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should be ok
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_owner_role;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+SET ROLE TO DEFAULT;
+
+SET ROLE TO regress_var_exec_role;
+
+-- should fail, but not crash
+SELECT var_read_func();
+
+SET ROLE TO DEFAULT;
+
+DROP FUNCTION var_read_func;
+
+REVOKE ALL ON SCHEMA public FROM regress_var_owner_role, regress_var_reader_role, regress_var_exec_role;
+
+DROP ROLE regress_var_owner_role;
+DROP ROLE regress_var_reader_role;
+DROP ROLE regress_var_exec_role;
+
+-- returns updated value
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+CREATE OR REPLACE FUNCTION inc_var_int(int)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var1 = COALESCE(plpgsql_sv_var1 + $1, $1);
+ RETURN plpgsql_sv_var1;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+SELECT inc_var_int(1);
+
+SELECT inc_var_int(1) FROM generate_series(1,10);
+
+CREATE VARIABLE plpgsql_sv_var2 AS numeric;
+
+LET plpgsql_sv_var2 = 0.0;
+
+CREATE OR REPLACE FUNCTION inc_var_num(numeric)
+RETURNS int AS $$
+BEGIN
+ LET plpgsql_sv_var2 = COALESCE(plpgsql_sv_var2 + $1, $1);
+ RETURN plpgsql_sv_var2;
+END;
+$$ LANGUAGE plpgsql;
+
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+SELECT inc_var_num(1.0);
+
+SELECT inc_var_num(1.0) FROM generate_series(1,10);
+
+DROP VARIABLE plpgsql_sv_var1, plpgsql_sv_var2;
+
+DROP FUNCTION inc_var_int;
+DROP FUNCTION inc_var_num;
+
+-- plpgsql variables are preferred against session variables
+CREATE VARIABLE plpgsql_sv_var1 AS int;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ plpgsql_sv_var1 := 1000;
+
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+DROP VARIABLE plpgsql_sv_var1;
+
+-- the value should not be corrupted
+CREATE VARIABLE plpgsql_sv_v text;
+LET plpgsql_sv_v = 'abc';
+
+CREATE FUNCTION ffunc()
+RETURNS text AS $$
+BEGIN
+ RETURN gfunc(plpgsql_sv_v);
+END
+$$ LANGUAGE plpgsql;
+
+CREATE FUNCTION gfunc(t text)
+RETURNS text AS $$
+BEGIN
+ LET plpgsql_sv_v = 'BOOM!';
+ RETURN t;
+END;
+$$ LANGUAGE plpgsql;
+
+select ffunc();
+
+DROP FUNCTION ffunc();
+DROP FUNCTION gfunc(text);
+
+DROP VARIABLE plpgsql_sv_v;
--
2.49.0
[text/x-patch] v20250515-0007-GUC-session_variables_ambiguity_warning.patch (15.1K, ../../CAFj8pRCEjG005L=1vGbir-odYdcYxByOAeFVJ_K9eRcRF=MbNQ@mail.gmail.com/6-v20250515-0007-GUC-session_variables_ambiguity_warning.patch)
download | inline diff:
From b345c17dbd8b7707b5c4e00b4003136962485037 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Tue, 21 May 2024 17:55:24 +0200
Subject: [PATCH 07/21] GUC session_variables_ambiguity_warning
Inside an query the session variables can be shadowed. This behaviour is by design,
because this ensuring so new variables doesn't break existing queries. But this
behaviour can be confusing, because shadowing is quiet.
When new GUC session_variables_ambiguity_warning is on, then the warning
is displayed, when some session variable can be used, but it is not used
due shadowing. This feature should to help with investigation of unexpected
behaviour.
Note: PLpgSQL has an option that controls priority of identifier's spaces
(SQL or PLpgSQL). Default behaviour doesn't allows collisions. I believe
this default is the best. I cannot to implement similar very strict
behaviour to session variables, because one unhappy named session variable
can breaks an applications. The problems related to badly named PLpgSQL's
varible is limitted just to only one routine.
---
doc/src/sgml/config.sgml | 60 +++++++++++++++++++
doc/src/sgml/ddl.sgml | 11 ++++
src/backend/parser/parse_expr.c | 49 +++++++++++++--
src/backend/utils/misc/guc_tables.c | 9 +++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/parser/parse_expr.h | 1 +
.../src/expected/plpgsql_session_variable.out | 33 ++++++++++
.../src/sql/plpgsql_session_variable.sql | 29 +++++++++
.../regress/expected/session_variables.out | 26 ++++++++
src/test/regress/sql/session_variables.sql | 26 ++++++++
10 files changed, 241 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 23d2b1be424..e34da8ab9d6 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -11374,6 +11374,66 @@ dynamic_library_path = '/usr/local/lib/postgresql:$libdir'
</listitem>
</varlistentry>
+ <varlistentry id="guc-session-variables-ambiguity-warning" xreflabel="session_variables_ambiguity_warning">
+ <term><varname>session_variables_ambiguity_warning</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>session_variables_ambiguity_warning</varname> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ When on, a warning is raised when any identifier in a query could be
+ used as both a column identifier, routine variable or a session
+ variable identifier. The default is <literal>off</literal>.
+ </para>
+ <para>
+ Session variables can be shadowed by column references in a query, this
+ is an expected behavior. Previously working queries shouldn't error out
+ by creating any session variable, so session variables are always shadowed
+ if an identifier is ambiguous. Variables should be referenced using
+ anunambiguous identifier without any possibility for a collision with
+ identifier of other database objects (column names or record fields names).
+ The warning messages emitted when enabling <varname>session_variables_ambiguity_warning</varname>
+ can help finding such identifier collision.
+<programlisting>
+CREATE TABLE foo(a int);
+INSERT INTO foo VALUES(10);
+CREATE VARIABLE a int;
+LET a = 100;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+ a
+----
+ 10
+(1 row)
+</screen>
+
+<programlisting>
+SET session_variables_ambiguity_warning TO on;
+SELECT a FROM foo;
+</programlisting>
+
+<screen>
+WARNING: session variable "a" is shadowed
+LINE 1: SELECT a FROM foo;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ a
+----
+ 10
+(1 row)
+</screen>
+ </para>
+ <para>
+ This feature can significantly increase log size, so it's disabled by
+ default. For testing or development environments it's recommended to
+ enable it if you use session variables.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-standard-conforming-strings" xreflabel="standard_conforming_strings">
<term><varname>standard_conforming_strings</varname> (<type>boolean</type>)
<indexterm><primary>strings</primary><secondary>standard conforming</secondary></indexterm>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index b3fc62056e9..3a3f6be79f2 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5446,6 +5446,17 @@ SELECT name FROM foo;
Alice
</programlisting>
</para>
+
+ <para>
+ When a query contains identifiers or qualified identifiers that could be
+ used as both a session variable identifiers and as column identifier,
+ then the column identifier is preferred every time. Warnings can be
+ emitted when this situation happens by enabling configuration parameter <xref
+ linkend="guc-session-variables-ambiguity-warning"/>. User can explicitly
+ qualify the source object by syntax <literal>table.column</literal> or
+ <literal>schema.variable</literal>. It is strongly recommended to rename
+ shadowed variables or use qualified names always.
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 988d1c66f56..b10e1bca308 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -45,6 +45,7 @@
/* GUC parameters */
bool Transform_null_equals = false;
+bool session_variables_ambiguity_warning = false;
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
@@ -960,11 +961,51 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
*
* SELECT foo.a, foo.b, foo.c FROM foo;
*
- * However, that is very confusing, so we disallow it. We don't try to
- * identify a variable if we know that it would be shadowed.
- * -----
+ * However, that is very confusing, so we disallow it.
+ *
+ * When session_variables_ambiguity_warning is requested, then we
+ * need to identify a variable although we know, so this variable
+ * would be shadowed.
*/
- if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ if (node || (relname && crerr == CRERR_NO_COLUMN))
+ {
+ /*
+ * In this path we just try (if it is wanted) detect if session
+ * variable is shadowed.
+ */
+ if (session_variables_ambiguity_warning)
+ {
+ /*
+ * The AccessShareLock is created on related session variable.
+ * The lock will be kept for the whole transaction.
+ */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, true);
+
+ if (OidIsValid(varid))
+ {
+ /* this path will ending by WARNING. Unlock variable first */
+ UnlockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (node)
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s\" is shadowed",
+ NameListToString(cref->fields)),
+ errdetail("Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name."),
+ parser_errposition(pstate, cref->location)));
+ else
+ /* session variable is shadowed by RTE */
+ ereport(WARNING,
+ (errcode(ERRCODE_AMBIGUOUS_COLUMN),
+ errmsg("session variable \"%s.%s\" is shadowed",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ errdetail("Session variables can be shadowed by tables or table's aliases with the same name."),
+ parser_errposition(pstate, cref->location)));
+ }
+ }
+ }
+ else
{
/* takes an AccessShareLock on the session variable */
varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 2f8cbd86759..31d70785b14 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1644,6 +1644,15 @@ struct config_bool ConfigureNamesBool[] =
false,
NULL, NULL, NULL
},
+ {
+ {"session_variables_ambiguity_warning", PGC_USERSET, CLIENT_CONN_STATEMENT,
+ gettext_noop("Raise a warning when reference to a session variable is ambiguous."),
+ NULL
+ },
+ &session_variables_ambiguity_warning,
+ false,
+ NULL, NULL, NULL
+ },
{
{"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
gettext_noop("Sets the default read-only status of new transactions."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 34826d01380..66c6577eceb 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -764,6 +764,7 @@ autovacuum_worker_slots = 16 # autovacuum worker slots to allocate
#default_transaction_read_only = off
#default_transaction_deferrable = off
#session_replication_role = 'origin'
+#session_variables_ambiguity_warning = off
#statement_timeout = 0 # in milliseconds, 0 is disabled
#transaction_timeout = 0 # in milliseconds, 0 is disabled
#lock_timeout = 0 # in milliseconds, 0 is disabled
diff --git a/src/include/parser/parse_expr.h b/src/include/parser/parse_expr.h
index efbaff8e710..d2209070181 100644
--- a/src/include/parser/parse_expr.h
+++ b/src/include/parser/parse_expr.h
@@ -17,6 +17,7 @@
/* GUC parameters */
extern PGDLLIMPORT bool Transform_null_equals;
+extern PGDLLIMPORT bool session_variables_ambiguity_warning;
extern Node *transformExpr(ParseState *pstate, Node *expr, ParseExprKind exprKind);
diff --git a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
index ab779900596..a6523f7afe2 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_session_variable.out
@@ -354,6 +354,39 @@ $$;
NOTICE: session variable is 100
NOTICE: plpgsql variable is 1000
NOTICE: variable is 1000
+-- againt with session_variables_ambiguity_warning(on)
+SET session_variables_ambiguity_warning TO on;
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+NOTICE: session variable is 100
+NOTICE: plpgsql variable is 1000
+WARNING: session variable "plpgsql_sv_var1" is shadowed
+LINE 1: plpgsql_sv_var1
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+QUERY: plpgsql_sv_var1
+NOTICE: variable is 1000
+SET session_variables_ambiguity_warning TO off;
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
CREATE VARIABLE plpgsql_sv_v text;
diff --git a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
index a3cc264cf38..9b8e90e81fa 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_session_variable.sql
@@ -260,6 +260,35 @@ BEGIN
END;
$$;
+-- againt with session_variables_ambiguity_warning(on)
+
+SET session_variables_ambiguity_warning TO on;
+
+DO $$
+<<myblock>>
+DECLARE plpgsql_sv_var1 int;
+BEGIN
+ LET plpgsql_sv_var1 = 100;
+
+ -- should be ok without warning
+ plpgsql_sv_var1 := 1000;
+
+ -- should be ok without warning
+ -- print 100;
+ RAISE NOTICE 'session variable is %', public.plpgsql_sv_var1;
+
+ -- should be ok without warning
+ -- print 1000
+ RAISE NOTICE 'plpgsql variable is %', myblock.plpgsql_sv_var1;
+
+ -- should to print plpgsql variable with warning
+ -- print 1000
+ RAISE NOTICE 'variable is %', plpgsql_sv_var1;
+END;
+$$;
+
+SET session_variables_ambiguity_warning TO off;
+
DROP VARIABLE plpgsql_sv_var1;
-- the value should not be corrupted
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 2783caa8446..7c350ad5ef9 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1524,6 +1524,9 @@ CREATE TABLE vartest_foo(a int, b int);
INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
-- should to fail
SELECT var1.* FROM vartest_foo;
ERROR: missing FROM-clause entry for table "var1"
@@ -1549,6 +1552,7 @@ SELECT count(var1.*) FROM vartest_foo var1;
2
(1 row)
+SET session_variables_ambiguity_warning TO off;
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
NOTICE: drop cascades to 2 other objects
@@ -1943,3 +1947,25 @@ SELECT var1;
(1 row)
DROP VARIABLE var1, var2;
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+CREATE VARIABLE xxtab.avar int;
+CREATE TABLE public.xxtab(avar int);
+INSERT INTO public.xxtab VALUES(1);
+LET xxtab.avar = 20;
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+WARNING: session variable "xxtab.avar" is shadowed
+LINE 1: SELECT xxtab.avar FROM public.xxtab;
+ ^
+DETAIL: Session variables can be shadowed by columns, routine's variables and routine's arguments with the same name.
+ avar
+------
+ 1
+(1 row)
+
+SET session_variables_ambiguity_warning TO off;
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
+NOTICE: drop cascades to session variable xxtab.avar
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index a624ab8b67f..68be415bf26 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1079,6 +1079,10 @@ INSERT INTO vartest_foo VALUES(10,20), (30,40);
CREATE VARIABLE var1 AS vartest_foo;
LET var1 = (100,200);
+-- no variable is shadowed here
+-- no warning expected
+SET session_variables_ambiguity_warning TO on;
+
-- should to fail
SELECT var1.* FROM vartest_foo;
@@ -1091,6 +1095,8 @@ SELECT count(var1.*) FROM vartest_foo;
-- should be ok
SELECT count(var1.*) FROM vartest_foo var1;
+SET session_variables_ambiguity_warning TO off;
+
SET SEARCH_PATH TO DEFAULT;
DROP SCHEMA vartest CASCADE;
@@ -1334,3 +1340,23 @@ BEGIN; DROP VARIABLE var1; ROLLBACK;
SELECT var1;
DROP VARIABLE var1, var2;
+
+-- test session_variables_ambiguity_warning
+CREATE SCHEMA xxtab;
+
+CREATE VARIABLE xxtab.avar int;
+
+CREATE TABLE public.xxtab(avar int);
+
+INSERT INTO public.xxtab VALUES(1);
+
+LET xxtab.avar = 20;
+
+SET session_variables_ambiguity_warning TO on;
+--- should to raise warning, show 1
+SELECT xxtab.avar FROM public.xxtab;
+
+SET session_variables_ambiguity_warning TO off;
+
+DROP TABLE public.xxtab;
+DROP SCHEMA xxtab CASCADE;
--
2.49.0
[text/x-patch] v20250515-0005-memory-cleaning-after-DROP-VARIABLE.patch (20.9K, ../../CAFj8pRCEjG005L=1vGbir-odYdcYxByOAeFVJ_K9eRcRF=MbNQ@mail.gmail.com/7-v20250515-0005-memory-cleaning-after-DROP-VARIABLE.patch)
download | inline diff:
From eee081259be8660dbda899bd94a183adbc57fa58 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <[email protected]>
Date: Wed, 13 Nov 2024 09:31:28 +0100
Subject: [PATCH 05/21] memory cleaning after DROP VARIABLE
Accepting a sinval message invalidates entries in the "sessionvars" hash table.
These entries are validated before any read or write operations on session variables.
When the entry cannot be validated, it is removed. Removal will be delayed when
the variable was dropped by the current transaction, which could still be rolled back.
---
src/backend/catalog/pg_variable.c | 7 +-
src/backend/commands/session_variable.c | 153 +++++++++++-
src/include/commands/session_variable.h | 2 +
.../isolation/expected/session-variable.out | 110 +++++++++
src/test/isolation/isolation_schedule | 1 +
.../isolation/specs/session-variable.spec | 50 ++++
.../regress/expected/session_variables.out | 217 ++++++++++++++++++
src/test/regress/sql/session_variables.sql | 120 ++++++++++
8 files changed, 655 insertions(+), 5 deletions(-)
create mode 100644 src/test/isolation/expected/session-variable.out
create mode 100644 src/test/isolation/specs/session-variable.spec
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index bb445e9434b..d672d2a9cb3 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -22,6 +22,7 @@
#include "catalog/pg_collation.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
@@ -230,7 +231,8 @@ CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
}
/*
- * Drop variable by OID
+ * Drop variable by OID, and register the needed session variable
+ * cleanup.
*/
void
DropVariableById(Oid varid)
@@ -250,4 +252,7 @@ DropVariableById(Oid varid)
ReleaseSysCache(tup);
table_close(rel, RowExclusiveLock);
+
+ /* do the necessary cleanup in local memory, if needed */
+ SessionVariableDropPostprocess(varid);
}
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index e1c86966998..1596d94fb03 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -14,6 +14,7 @@
*/
#include "postgres.h"
+#include "access/xact.h"
#include "catalog/pg_variable.h"
#include "commands/session_variable.h"
#include "executor/svariableReceiver.h"
@@ -67,6 +68,14 @@ typedef struct SVariableData
void *domain_check_extra;
LocalTransactionId domain_check_extra_lxid;
+ /*
+ * Top level local transaction id of the last transaction that dropped the
+ * variable, if any. We need this information to avoid freeing memory for
+ * variables dropped by the local backend, in case the operation is rolled
+ * back.
+ */
+ LocalTransactionId drop_lxid;
+
/*
* Stored value and type description can be outdated when we receive a
* sinval message. We then have to check if the stored data are still
@@ -83,6 +92,17 @@ static HTAB *sessionvars = NULL; /* hash table for session variables */
static MemoryContext SVariableMemoryContext = NULL;
+/* becomes true when we receive a sinval message */
+static bool needs_validation = false;
+
+/*
+ * The content of dropped session variables is not removed immediately. We do
+ * that in the next transaction that reads or writes a session variable.
+ * "validated_lxid" stores the transaction that performed said validation, so
+ * that we can avoid repeating the effort.
+ */
+static LocalTransactionId validated_lxid = InvalidLocalTransactionId;
+
/*
* Callback function for session variable invalidation.
*/
@@ -114,6 +134,38 @@ pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
if (hashvalue == 0 || svar->hashvalue == hashvalue)
{
svar->is_valid = false;
+ needs_validation = true;
+ }
+ }
+}
+
+/*
+ * Handle the local memory cleanup for a DROP VARIABLE command.
+ *
+ * Caller should take care of removing the pg_variable entry first.
+ */
+void
+SessionVariableDropPostprocess(Oid varid)
+{
+ Assert(LocalTransactionIdIsValid(MyProc->vxid.lxid));
+
+ if (sessionvars)
+ {
+ bool found;
+ SVariable svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_FIND, &found);
+
+ if (found)
+ {
+ /*
+ * Save the current top level local transaction id to make sure we
+ * won't automatically remove the local variable storage in
+ * validate_all_session_variables() when the invalidation message
+ * from DROP VARIABLE arrives. After all, the transaction could
+ * still be rolled back.
+ */
+ svar->is_valid = false;
+ svar->drop_lxid = MyProc->vxid.lxid;
}
}
}
@@ -167,6 +219,67 @@ is_session_variable_valid(SVariable svar)
return result;
}
+/*
+ * Check all potentially invalid session variable data in local memory and free
+ * the memory for all invalid ones. This function is called before any read or
+ * write of a session variable. Freeing of a variable's memory is postponed if
+ * the variable has been dropped by the current transaction, since that
+ * operation could still be rolled back.
+ *
+ * It is possible that we receive a cache invalidation message while
+ * remove_invalid_session_variables() is executing, so we cannot guarantee that
+ * all entries in "sessionvars" will be set to "is_valid" after the function is
+ * done. However, we can guarantee that all entries get checked once.
+ */
+static void
+remove_invalid_session_variables(void)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ /*
+ * The validation requires system catalog access, so the session state
+ * should be "in transaction".
+ */
+ Assert(IsTransactionState());
+
+ if (!needs_validation || !sessionvars)
+ return;
+
+ /*
+ * Reset the flag before we start the validation. It can be set again
+ * by concurrently incoming sinval messages.
+ */
+ needs_validation = false;
+
+ elog(DEBUG1, "effective call of validate_all_session_variables()");
+
+ hash_seq_init(&status, sessionvars);
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (!svar->is_valid)
+ {
+ if (svar->drop_lxid == MyProc->vxid.lxid)
+ {
+ /* try again in the next transaction */
+ needs_validation = true;
+ continue;
+ }
+
+ if (!is_session_variable_valid(svar))
+ {
+ Oid varid = svar->varid;
+
+ free_session_variable_value(svar);
+ hash_search(sessionvars, &varid, HASH_REMOVE, NULL);
+ svar = NULL;
+ }
+ else
+ svar->is_valid = true;
+ }
+ }
+}
+
/*
* Initialize attributes cached in "svar"
*/
@@ -196,6 +309,8 @@ setup_session_variable(SVariable svar, Oid varid)
svar->domain_check_extra = NULL;
svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+ svar->drop_lxid = InvalidTransactionId;
+
svar->isnull = true;
svar->value = (Datum) 0;
@@ -319,22 +434,42 @@ get_session_variable(Oid varid)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
if (found)
{
+ /*
+ * The session variable could have been dropped by a DROP VARIABLE
+ * statement in a subtransaction that was later rolled back, which
+ * means that we may have to work with the data of a variable marked
+ * as invalid.
+ */
if (!svar->is_valid)
{
/*
- * If there was an invalidation message, the variable might still be
- * valid, but we have to check with the system catalog.
+ * We have to check the system catalog to see if the variable is
+ * still valid, even if an invalidation message set it to invalid.
+ *
+ * The variable must be validated before it is accessed. The oid
+ * should be valid, because the related session variable is already
+ * locked, and remove_invalid_session_variables() would remove
+ * variables dropped by other transactions.
*/
if (is_session_variable_valid(svar))
svar->is_valid = true;
else
- /* if the value cannot be validated, we have to discard it */
- free_session_variable_value(svar);
+ elog(ERROR, "unexpected state of session variable %u", varid);
}
}
else
@@ -395,6 +530,16 @@ SetSessionVariable(Oid varid, Datum value, bool isNull)
if (!sessionvars)
create_sessionvars_hashtables();
+ if (validated_lxid == InvalidLocalTransactionId ||
+ validated_lxid != MyProc->vxid.lxid)
+ {
+ /* free the memory from dropped session variables */
+ remove_invalid_session_variables();
+
+ /* don't repeat the above step in the same transaction */
+ validated_lxid = MyProc->vxid.lxid;
+ }
+
svar = (SVariable) hash_search(sessionvars, &varid,
HASH_ENTER, &found);
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
index a8ca43c87af..d3cc79b5608 100644
--- a/src/include/commands/session_variable.h
+++ b/src/include/commands/session_variable.h
@@ -21,6 +21,8 @@
#include "tcop/cmdtag.h"
#include "utils/queryenvironment.h"
+extern void SessionVariableDropPostprocess(Oid varid);
+
extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
extern Datum GetSessionVariable(Oid varid, bool *isNull);
diff --git a/src/test/isolation/expected/session-variable.out b/src/test/isolation/expected/session-variable.out
new file mode 100644
index 00000000000..0a5579dc7ce
--- /dev/null
+++ b/src/test/isolation/expected/session-variable.out
@@ -0,0 +1,110 @@
+Parsed test spec with 4 sessions
+
+starting permutation: let val drop val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+
+starting permutation: let val s1 drop val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step drop: DROP VARIABLE myvar;
+step val: SELECT myvar;
+ERROR: column "myvar" does not exist
+step sr1: ROLLBACK;
+
+starting permutation: let val dbg drop create dbg val
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name|removed
+------+----+-------
+ | |t
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+
+starting permutation: let val s1 dbg drop create dbg val sr1
+step let: LET myvar = 'test';
+step val: SELECT myvar;
+myvar
+-----
+test
+(1 row)
+
+step s1: BEGIN;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step drop: DROP VARIABLE myvar;
+step create: CREATE VARIABLE myvar AS text;
+step dbg: SELECT schema, name, removed FROM pg_session_variables();
+schema|name |removed
+------+-----+-------
+public|myvar|f
+(1 row)
+
+step val: SELECT myvar;
+myvar
+-----
+
+(1 row)
+
+step sr1: ROLLBACK;
+
+starting permutation: create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
+step create3: CREATE VARIABLE myvar3 AS text;
+step let3: LET myvar3 = 'test';
+step s3: BEGIN;
+step create4: CREATE VARIABLE myvar4 AS text;
+step let4: LET myvar4 = 'test';
+step drop4: DROP VARIABLE myvar4;
+step drop3: DROP VARIABLE myvar3;
+step inval3: SELECT COUNT(*) >= 0 FROM pg_foreign_table;
+?column?
+--------
+t
+(1 row)
+
+step discard: DISCARD VARIABLES;
+step sc3: COMMIT;
+step state: SELECT varname FROM pg_variable;
+varname
+-------
+myvar
+(1 row)
+
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index e3c669a29c7..8df901fc79c 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -116,3 +116,4 @@ test: serializable-parallel-2
test: serializable-parallel-3
test: matview-write-skew
test: lock-nowait
+test: session-variable
diff --git a/src/test/isolation/specs/session-variable.spec b/src/test/isolation/specs/session-variable.spec
new file mode 100644
index 00000000000..c864fee4006
--- /dev/null
+++ b/src/test/isolation/specs/session-variable.spec
@@ -0,0 +1,50 @@
+# Test session variables memory cleanup for sinval
+
+setup
+{
+ CREATE VARIABLE myvar AS text;
+}
+
+teardown
+{
+ DROP VARIABLE IF EXISTS myvar;
+}
+
+session s1
+step s1 { BEGIN; }
+step let { LET myvar = 'test'; }
+step val { SELECT myvar; }
+step dbg { SELECT schema, name, removed FROM pg_session_variables(); }
+step sr1 { ROLLBACK; }
+
+session s2
+step drop { DROP VARIABLE myvar; }
+step create { CREATE VARIABLE myvar AS text; }
+
+session s3
+step s3 { BEGIN; }
+step let3 { LET myvar3 = 'test'; }
+step create4 { CREATE VARIABLE myvar4 AS text; }
+step let4 { LET myvar4 = 'test'; }
+step drop4 { DROP VARIABLE myvar4; }
+step inval3 { SELECT COUNT(*) >= 0 FROM pg_foreign_table; }
+step discard { DISCARD VARIABLES; }
+step sc3 { COMMIT; }
+step state { SELECT varname FROM pg_variable; }
+
+session s4
+step create3 { CREATE VARIABLE myvar3 AS text; }
+step drop3 { DROP VARIABLE myvar3; }
+
+# Concurrent drop of a known variable should lead to an error
+permutation let val drop val
+# Same, but with an explicit transaction
+permutation let val s1 drop val sr1
+# Concurrent drop/create of a known variable should lead to empty variable
+permutation let val dbg drop create dbg val
+# Concurrent drop/create of a known variable should lead to empty variable
+# We need a transaction to make sure that we won't accept invalidation when
+# calling the dbg step after the concurrent drop
+permutation let val s1 dbg drop create dbg val sr1
+# test for DISCARD ALL when all internal queues have actions registered
+permutation create3 let3 s3 create4 let4 drop4 drop3 inval3 discard sc3 state
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index 79ac40768f8..2783caa8446 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -1726,3 +1726,220 @@ SELECT count(*) FROM pg_session_variables();
0
(1 row)
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+-------------------+------------+------------
+ var1 | character varying | t | t
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+-- should fail
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+ var1
+------
+ Ahoj
+(1 row)
+
+DROP VARIABLE var1;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ name | typname | can_select | can_update
+------+---------+------------+------------
+ var1 | integer | t | t
+(1 row)
+
+ DROP VARIABLE var1;
+COMMIT;
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+ count
+-------
+ 0
+(1 row)
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ var2
+------
+ 0
+(1 row)
+
+COMMIT;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+DROP VARIABLE var1, var2;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index 2954759aaed..a624ab8b67f 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -1214,3 +1214,123 @@ DISCARD VARIABLES;
-- should be zero again
SELECT count(*) FROM pg_session_variables();
+
+-- dropped variables should be removed from memory before the next usage
+-- of any session variable in the next transaction
+
+LET var1 = 'Ahoj';
+SELECT name, typname, can_select, can_update FROM pg_session_variables();
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+-- the content of the value should be preserved when a variable is dropped
+-- by an aborted transaction
+CREATE VARIABLE var1 AS varchar;
+LET var1 = 'Ahoj';
+BEGIN;
+DROP VARIABLE var1;
+
+-- should fail
+SELECT var1;
+
+ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+-- another test
+BEGIN;
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 100;
+-- should be ok, result 100
+SELECT var1;
+ROLLBACK;
+-- should be ok, result 'Ahoj'
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+BEGIN;
+ CREATE VARIABLE var1 AS int;
+ LET var1 = 100;
+ SELECT var1;
+ SELECT name, typname, can_select, can_update FROM pg_session_variables();
+ DROP VARIABLE var1;
+COMMIT;
+
+-- should be zero
+SELECT count(*) FROM pg_session_variables() WHERE NOT removed;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int;
+LET var1 = 10;
+LET var2 = 0;
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ ROLLBACK TO s2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ SAVEPOINT s2;
+ DROP VARIABLE var1;
+ SELECT var2;
+ROLLBACK;
+-- should be ok
+SELECT var1;
+
+BEGIN;
+ SAVEPOINT s1;
+ DROP VARIABLE var1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+
+ SAVEPOINT s2;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+ ROLLBACK TO s1;
+ -- force cleaning by touching another session variable
+ SELECT var2;
+COMMIT;
+-- should be ok
+SELECT var1;
+
+-- repeated aborted transaction
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+BEGIN; DROP VARIABLE var1; ROLLBACK;
+
+-- should be ok
+SELECT var1;
+
+DROP VARIABLE var1, var2;
--
2.49.0
[text/x-patch] v20250515-0003-function-pg_session_variables-for-cleaning-tests.patch (4.4K, ../../CAFj8pRCEjG005L=1vGbir-odYdcYxByOAeFVJ_K9eRcRF=MbNQ@mail.gmail.com/8-v20250515-0003-function-pg_session_variables-for-cleaning-tests.patch)
download | inline diff:
From 4965c6e99a82930074b319c1762cd3ff6a41ed07 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 20:01:56 +0100
Subject: [PATCH 03/21] function pg_session_variables for cleaning tests
This is a function designed for testing and debugging. It returns the
content of sessionvars as-is, and can therefore display entries about
session variables that were dropped but for which this backend didn't
process the shared invalidations yet.
---
src/backend/commands/session_variable.c | 92 +++++++++++++++++++++++++
src/include/catalog/pg_proc.dat | 8 +++
2 files changed, 100 insertions(+)
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
index d2891a1dcb7..fa16f47072e 100644
--- a/src/backend/commands/session_variable.c
+++ b/src/backend/commands/session_variable.c
@@ -527,3 +527,95 @@ ExecuteLetStmt(ParseState *pstate,
PopActiveSnapshot();
}
+
+/*
+ * pg_session_variables - designed for testing
+ *
+ * This is a function designed for testing and debugging. It returns the
+ * content of session variables as-is, and can therefore display data about
+ * session variables that were dropped, but for which this backend didn't
+ * process the shared invalidations yet.
+ */
+Datum
+pg_session_variables(PG_FUNCTION_ARGS)
+{
+#define NUM_PG_SESSION_VARIABLES_ATTS 8
+
+ InitMaterializedSRF(fcinfo, 0);
+
+ if (sessionvars)
+ {
+ ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ Datum values[NUM_PG_SESSION_VARIABLES_ATTS];
+ bool nulls[NUM_PG_SESSION_VARIABLES_ATTS];
+ HeapTuple tp;
+ bool var_is_valid = false;
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, 0, sizeof(nulls));
+
+ values[0] = ObjectIdGetDatum(svar->varid);
+ values[3] = ObjectIdGetDatum(svar->typid);
+
+ /*
+ * It is possible that the variable has been dropped from the
+ * catalog, but not yet purged from the hash table.
+ */
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ Form_pg_variable varform = (Form_pg_variable) GETSTRUCT(tp);
+
+ /*
+ * It is also possible that a variable has been dropped and
+ * someone created a new variable with the same object ID. Use
+ * the catalog information only if that is not the case.
+ */
+ if (svar->create_lsn == varform->varcreate_lsn)
+ {
+ values[1] = CStringGetTextDatum(
+ get_namespace_name(varform->varnamespace));
+
+ values[2] = CStringGetTextDatum(NameStr(varform->varname));
+ values[4] = CStringGetTextDatum(format_type_be(svar->typid));
+ values[5] = BoolGetDatum(false);
+
+ values[6] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_SELECT) == ACLCHECK_OK);
+
+ values[7] = BoolGetDatum(
+ object_aclcheck(VariableRelationId, svar->varid,
+ GetUserId(), ACL_UPDATE) == ACLCHECK_OK);
+
+ var_is_valid = true;
+ }
+
+ ReleaseSysCache(tp);
+ }
+
+ /* if there is no matching catalog entry, return null values */
+ if (!var_is_valid)
+ {
+ nulls[1] = true;
+ nulls[2] = true;
+ nulls[4] = true;
+ values[5] = BoolGetDatum(true);
+ nulls[6] = true;
+ nulls[7] = true;
+ }
+
+ tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls);
+ }
+ }
+
+ return (Datum) 0;
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index da772ff9e17..0662f0d6891 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -12589,4 +12589,12 @@
proargnames => '{pid,io_id,io_generation,state,operation,off,length,target,handle_data_len,raw_result,result,target_desc,f_sync,f_localmem,f_buffered}',
prosrc => 'pg_get_aios' },
+# Session variables support
+{ oid => '8488', descr => 'list of used session variables',
+ proname => 'pg_session_variables', prorows => '1000', proretset => 't',
+ provolatile => 's', proparallel => 'r', prorettype => 'record',
+ proargtypes => '', proallargtypes => '{oid,text,text,oid,text,bool,bool,bool}',
+ proargmodes => '{o,o,o,o,o,o,o,o}',
+ proargnames => '{varid,schema,name,typid,typname,removed,can_select,can_update}',
+ prosrc => 'pg_session_variables' },
]
--
2.49.0
[text/x-patch] v20250515-0002-Storage-for-session-variables-and-SQL-interface.patch (159.7K, ../../CAFj8pRCEjG005L=1vGbir-odYdcYxByOAeFVJ_K9eRcRF=MbNQ@mail.gmail.com/9-v20250515-0002-Storage-for-session-variables-and-SQL-interface.patch)
download | inline diff:
From 0a16e825e50bb0bb432448fa294efd88fc46bae7 Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Thu, 6 Jul 2023 08:29:21 +0200
Subject: [PATCH 02/21] Storage for session variables and SQL interface
Session variables are stored in session memory in a dedicated hash table.
They are set by the LET command and read by the SELECT command.
The access rights should be checked.
The identifiers of session variables should always be shadowed by possible
column identifiers: we don't want to break an application by creating some
badly named session variable.
The limits of this patch (solved by other patches):
- session variables block parallel execution
- session variables blocks simple expression evaluation (in plpgsql)
- SQL functions with session variables are not inlined
- CALL statement is not supported (usage of direct access to express executor)
- EXECUTE statement is not supported (usage of direct access to express executor)
- memory used by dropped session variables is not released
Implementations of EXPLAIN LET and PREPARE LET statements
are in separate patches (for better readability)
---
doc/src/sgml/catalogs.sgml | 13 +
doc/src/sgml/ddl.sgml | 61 +
doc/src/sgml/func.sgml | 4 +-
doc/src/sgml/glossary.sgml | 5 +-
doc/src/sgml/parallel.sgml | 6 +
doc/src/sgml/plpgsql.sgml | 14 +
doc/src/sgml/ref/allfiles.sgml | 1 +
doc/src/sgml/ref/alter_variable.sgml | 1 +
doc/src/sgml/ref/create_variable.sgml | 5 +-
doc/src/sgml/ref/drop_variable.sgml | 1 +
doc/src/sgml/ref/let.sgml | 96 ++
doc/src/sgml/reference.sgml | 1 +
src/backend/catalog/dependency.c | 5 +
src/backend/catalog/namespace.c | 289 ++++
src/backend/catalog/pg_variable.c | 2 +
src/backend/commands/Makefile | 1 +
src/backend/commands/meson.build | 1 +
src/backend/commands/prepare.c | 10 +
src/backend/commands/session_variable.c | 529 +++++++
src/backend/executor/Makefile | 1 +
src/backend/executor/execExpr.c | 32 +
src/backend/executor/execMain.c | 66 +
src/backend/executor/meson.build | 1 +
src/backend/executor/svariableReceiver.c | 172 +++
src/backend/nodes/nodeFuncs.c | 10 +
src/backend/optimizer/plan/planner.c | 36 +
src/backend/optimizer/plan/setrefs.c | 156 ++-
src/backend/optimizer/prep/prepjointree.c | 3 +
src/backend/optimizer/util/clauses.c | 33 +-
src/backend/parser/analyze.c | 272 +++-
src/backend/parser/gram.y | 39 +-
src/backend/parser/parse_agg.c | 9 +
src/backend/parser/parse_expr.c | 223 ++-
src/backend/parser/parse_func.c | 2 +
src/backend/parser/parse_merge.c | 1 +
src/backend/tcop/dest.c | 7 +
src/backend/tcop/utility.c | 16 +
src/backend/utils/adt/ruleutils.c | 46 +
src/backend/utils/cache/plancache.c | 41 +-
src/backend/utils/fmgr/fmgr.c | 10 +-
src/bin/psql/tab-complete.in.c | 12 +-
src/include/catalog/namespace.h | 1 +
src/include/catalog/pg_variable.h | 9 +
src/include/commands/session_variable.h | 30 +
src/include/executor/svariableReceiver.h | 22 +
src/include/nodes/execnodes.h | 14 +
src/include/nodes/parsenodes.h | 17 +
src/include/nodes/pathnodes.h | 14 +
src/include/nodes/plannodes.h | 9 +
src/include/nodes/primnodes.h | 14 +
src/include/optimizer/planmain.h | 2 +
src/include/parser/kwlist.h | 1 +
src/include/parser/parse_node.h | 3 +
src/include/tcop/cmdtaglist.h | 1 +
src/include/tcop/dest.h | 1 +
src/pl/plpgsql/src/pl_exec.c | 3 +-
.../regress/expected/session_variables.out | 1232 +++++++++++++++++
src/test/regress/sql/session_variables.sql | 883 ++++++++++++
src/tools/pgindent/typedefs.list | 5 +
59 files changed, 4467 insertions(+), 27 deletions(-)
create mode 100644 doc/src/sgml/ref/let.sgml
create mode 100644 src/backend/commands/session_variable.c
create mode 100644 src/backend/executor/svariableReceiver.c
create mode 100644 src/include/commands/session_variable.h
create mode 100644 src/include/executor/svariableReceiver.h
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index fc562361792..0041e61dddd 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -9831,6 +9831,19 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcreate_lsn</structfield> <type>pg_lsn</type>
+ </para>
+ <para>
+ LSN of the transaction where the variable was created.
+ <structfield>varcreate_lsn</structfield> and
+ <structfield>oid</structfield> together form the all-time unique
+ identifier (<structfield>oid</structfield> alone is not enough, since
+ object identifiers can get reused).
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>varname</structfield> <type>name</type>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 66fa267facc..b3fc62056e9 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -5385,6 +5385,67 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
The session variable holds value in session memory. This value is private
to each session and is released when the session ends.
</para>
+
+ <para>
+ The value of a session variable is set with the SQL statement
+ <command>LET</command>. The value of a session variable can be retrieved
+ with the SQL statement <command>SELECT</command>.
+<programlisting>
+CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
+</programlisting>
+
+ or
+
+<programlisting>
+CREATE VARIABLE public.current_user_id AS integer;
+GRANT SELECT ON VARIABLE public.current_user_id TO PUBLIC;
+LET current_user_id = (SELECT id FROM users WHERE usename = session_user);
+SELECT current_user_id;
+</programlisting>
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a variable's value returns a <literal>NULL</literal>, unless its value has
+ been set to something else in the current session using the
+ <command>LET</command> command. Session variables are not transactional:
+ any changes made to the value of a session variable in a transaction won't
+ be undone if the transaction is rolled back (just like variables in
+ procedural languages). Session variables themselves are persistent, but
+ their values are neither persistent nor shared (like the content of
+ temporary tables).
+ </para>
+
+ <para>
+ Inside a query or an expression, a session variable can be
+ <quote>shadowed</quote> by a column with the same name. Similarly, the
+ name of a function or procedure argument or a PL/pgSQL variable (see
+ <xref linkend="plpgsql-declarations"/>) can shadow a session variable
+ in the routine's body. Such collisions of identifiers can be resolved
+ by using qualified identifiers: Session variables can be qualified with
+ the schema name, columns can use table aliases, routine variables can use
+ block labels, and routine arguments can use the routine name.
+<programlisting>
+CREATE VARIABLE name AS text;
+LET name = 'John';
+
+CREATE TABLE foo(name text);
+INSERT INTO foo VALUES('Alice');
+
+-- variable name is shadowed
+SELECT name FROM foo;
+</programlisting>
+
+ which returns:
+
+<programlisting>
+ name
+-------
+ Alice
+</programlisting>
+ </para>
</sect1>
<sect1 id="ddl-others">
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 0fdf613dc5e..e51007fdd6a 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25860,8 +25860,8 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
't' for <literal>TABLESPACE</literal>,
'F' for <literal>FOREIGN DATA WRAPPER</literal>,
'S' for <literal>FOREIGN SERVER</literal>,
- or
- 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal>.
+ 'T' for <literal>TYPE</literal> or <literal>DOMAIN</literal> or
+ 'V' for <literal>SESSION VARIABLE</literal>.
</para></entry>
</row>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index 83b13f98f28..2d13dcea4ef 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1714,8 +1714,9 @@
<para>
A persistent database object that holds a value in session memory. This
value is private to each session and is released when the session ends.
- Read or write access to session variables is controlled by privileges,
- similar to other database objects.
+ The default value of the session variable is null. Read or write access
+ to session variables is controlled by privileges, similar to other database
+ objects.
</para>
<para>
For more information, see <xref linkend="ddl-session-variables"/>.
diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index 1ce9abf86f5..683dede6adc 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -515,6 +515,12 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
Plan nodes that reference a correlated <literal>SubPlan</literal>.
</para>
</listitem>
+
+ <listitem>
+ <para>
+ Plan nodes that use a session variable.
+ </para>
+ </listitem>
</itemizedlist>
<sect2 id="parallel-labeling">
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index e937491e6b8..1e4c43b8b61 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -6036,6 +6036,20 @@ $$ LANGUAGE plpgsql STRICT IMMUTABLE;
</programlisting>
</para>
</sect3>
+
+ <sect3 id="plpgsql-porting-package-variables">
+ <title><command>Packages and package variables</command></title>
+
+ <para>
+ The <application>PL/pgSQL</application> language has no packages, and
+ therefore no package variables or package constants.
+ You can consider translating an Oracle package into a schema in
+ <productname>PostgreSQL</productname>. Package functions and procedures
+ would then become functions and procedures in that schema, and package
+ variables could be translated to session variables in that schema.
+ (see <xref linkend="ddl-session-variables"/>).
+ </para>
+ </sect3>
</sect2>
<sect2 id="plpgsql-porting-appendix">
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index 2f67de3e21b..cc3bd5ab540 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -158,6 +158,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY grant SYSTEM "grant.sgml">
<!ENTITY importForeignSchema SYSTEM "import_foreign_schema.sgml">
<!ENTITY insert SYSTEM "insert.sgml">
+<!ENTITY let SYSTEM "let.sgml">
<!ENTITY listen SYSTEM "listen.sgml">
<!ENTITY load SYSTEM "load.sgml">
<!ENTITY lock SYSTEM "lock.sgml">
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
index 96d2586423e..221a699469b 100644
--- a/doc/src/sgml/ref/alter_variable.sgml
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -173,6 +173,7 @@ ALTER VARIABLE boo SET SCHEMA private;
<simplelist type="inline">
<member><xref linkend="sql-createvariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
</refentry>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
index 6e988f2e472..cd9ff63975a 100644
--- a/doc/src/sgml/ref/create_variable.sgml
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -120,9 +120,11 @@ CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceab
<title>Examples</title>
<para>
- Create an date session variable <literal>var1</literal>:
+ Create a session variable <literal>var1</literal> of data type date:
<programlisting>
CREATE VARIABLE var1 AS date;
+LET var1 = current_date;
+SELECT var1;
</programlisting>
</para>
@@ -143,6 +145,7 @@ CREATE VARIABLE var1 AS date;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-dropvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
index 5bdb3560f0b..67988b5fcd8 100644
--- a/doc/src/sgml/ref/drop_variable.sgml
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -111,6 +111,7 @@ DROP VARIABLE var1;
<simplelist type="inline">
<member><xref linkend="sql-altervariable"/></member>
<member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-let"/></member>
</simplelist>
</refsect1>
diff --git a/doc/src/sgml/ref/let.sgml b/doc/src/sgml/ref/let.sgml
new file mode 100644
index 00000000000..00f9bea91fe
--- /dev/null
+++ b/doc/src/sgml/ref/let.sgml
@@ -0,0 +1,96 @@
+<!--
+doc/src/sgml/ref/let.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-let">
+ <indexterm zone="sql-let">
+ <primary>LET</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>changing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>LET</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>LET</refname>
+ <refpurpose>change a session variable's value</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+LET <replaceable class="parameter">session_variable</replaceable> = <replaceable class="parameter">sql_expression</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>LET</command> command assigns a value to the specified session
+ variable.
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">session_variable</replaceable></term>
+ <listitem>
+ <para>
+ The name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">sql_expression</replaceable></term>
+ <listitem>
+ <para>
+ An arbitrary SQL expression. The result must be of a data type that can
+ be cast to the type of the session variable in an assignment.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+<programlisting>
+CREATE VARIABLE myvar AS integer;
+LET myvar = 10;
+LET myvar = (SELECT sum(val) FROM tab);
+</programlisting>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>LET</command> is a <productname>PostgreSQL</productname>
+ extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index 25578f3946c..13e4adc5df3 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -186,6 +186,7 @@
&grant;
&importForeignSchema;
&insert;
+ &let;
&listen;
&load;
&lock;
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 9e0f648b74f..90c9e8bb254 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1864,6 +1864,11 @@ find_expr_references_walker(Node *node,
{
Param *param = (Param *) node;
+ /* a variable parameter depends on the session variable */
+ if (param->paramkind == PARAM_VARIABLE)
+ add_object_address(VariableRelationId, param->paramvarid, 0,
+ context->addrs);
+
/* A parameter must depend on the parameter's datatype */
add_object_address(TypeRelationId, param->paramtype, 0,
context->addrs);
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 4307cad15c7..beafee2a341 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -3497,6 +3497,295 @@ NamesFromList(List *names)
return result;
}
+/* -----
+ * IdentifyVariable - try to find a variable from a list of identifiers
+ *
+ * Returns the OID of the variable found, or InvalidOid.
+ *
+ * "names" is a list of up to four identifiers; possible meanings are:
+ * - variable (searched on the search_path)
+ * - schema.variable
+ * - variable.attribute (searched on the search_path)
+ * - schema.variable.attribute
+ * - database.schema.variable
+ * - database.schema.variable.attribute
+ *
+ * If there is more than one way to identify a variable, "not_unique" will be
+ * set to true.
+ *
+ * Unless "noerror" is true, an error is raised if there are more than four
+ * identifiers in the list, or if the named database is not the current one.
+ * This is useful if we want to identify a shadowed variable.
+ *
+ * If an attribute is identified, it is stored in "attrname", otherwise the
+ * parameter is set to NULL.
+ *
+ * The identified session variable will be locked with an AccessShareLock.
+ * -----
+ */
+Oid
+IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror)
+{
+ Oid varid = InvalidOid;
+ Oid old_varid = InvalidOid;
+ uint64 inval_count;
+ bool retry = false;
+
+ /*
+ * DDL operations can change the results of a name lookup. Since all such
+ * operations will generate invalidation messages, we keep track of
+ * whether any such messages show up while we're performing the operation,
+ * and retry until either (1) no more invalidation messages show up or (2)
+ * the answer doesn't change.
+ */
+ for (;;)
+ {
+ Node *field1 = NULL;
+ Node *field2 = NULL;
+ Node *field3 = NULL;
+ Node *field4 = NULL;
+ char *a = NULL;
+ char *b = NULL;
+ char *c = NULL;
+ char *d = NULL;
+ Oid varoid_without_attr = InvalidOid;
+ Oid varoid_with_attr = InvalidOid;
+
+ *not_unique = false;
+ *attrname = NULL;
+ varid = InvalidOid;
+
+ inval_count = SharedInvalidMessageCounter;
+
+ switch (list_length(names))
+ {
+ case 1:
+ field1 = linitial(names);
+
+ Assert(IsA(field1, String));
+
+ varid = LookupVariable(NULL, strVal(field1), true);
+ break;
+
+ case 2:
+ field1 = linitial(names);
+ field2 = lsecond(names);
+
+ Assert(IsA(field1, String));
+ a = strVal(field1);
+
+ if (IsA(field2, String))
+ {
+ /* when both fields are of string type */
+ b = strVal(field2);
+
+ /*
+ * a.b can mean "schema"."variable" or
+ * "variable"."attribute". Check both variants, and
+ * returns InvalidOid with not_unique flag, when both
+ * interpretations are possible.
+ */
+ varoid_without_attr = LookupVariable(a, b, true);
+ varoid_with_attr = LookupVariable(NULL, a, true);
+ }
+ else
+ {
+ /* the last field of list can be star too */
+ Assert(IsA(field2, A_Star));
+
+ /*
+ * The syntax ident.* is used only by relation aliases,
+ * and then this identifier cannot be a reference to
+ * session variable.
+ */
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = b;
+ varid = varoid_with_attr;
+ }
+ break;
+
+ case 3:
+ {
+ bool field1_is_catalog = false;
+
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+
+ if (IsA(field3, String))
+ {
+ c = strVal(field3);
+
+ /*
+ * a.b.c can mean catalog.schema.variable or
+ * schema.variable.attribute.
+ *
+ * Check both variants, and set not_unique flag, when
+ * both interpretations are possible.
+ *
+ * When third node is star, only possible
+ * interpretation is schema.variable.*, but this
+ * pattern is not supported now.
+ */
+ varoid_with_attr = LookupVariable(a, b, true);
+
+ /*
+ * check pattern catalog.schema.variable only when
+ * there is possibility to success.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) == 0)
+ {
+ field1_is_catalog = true;
+ varoid_without_attr = LookupVariable(b, c, true);
+ }
+ }
+ else
+ {
+ Assert(IsA(field3, A_Star));
+ return InvalidOid;
+ }
+
+ if (OidIsValid(varoid_without_attr) && OidIsValid(varoid_with_attr))
+ {
+ *not_unique = true;
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_without_attr))
+ {
+ varid = varoid_without_attr;
+ }
+ else if (OidIsValid(varoid_with_attr))
+ {
+ *attrname = c;
+ varid = varoid_with_attr;
+ }
+
+ /*
+ * When we didn't find variable, we can (when it is
+ * allowed) raise cross-database reference error.
+ */
+ if (!OidIsValid(varid) && !noerror && !field1_is_catalog)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+ break;
+
+ case 4:
+ {
+ field1 = linitial(names);
+ field2 = lsecond(names);
+ field3 = lthird(names);
+ field4 = lfourth(names);
+
+ Assert(IsA(field1, String));
+ Assert(IsA(field2, String));
+ Assert(IsA(field3, String));
+
+ a = strVal(field1);
+ b = strVal(field2);
+ c = strVal(field3);
+
+ /*
+ * In this case, "a" is used as catalog name - check it.
+ */
+ if (strcmp(a, get_database_name(MyDatabaseId)) != 0)
+ {
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ }
+
+ if (IsA(field4, String))
+ {
+ d = strVal(field4);
+ }
+ else
+ {
+ Assert(IsA(field4, A_Star));
+ return InvalidOid;
+ }
+
+ *attrname = d;
+ varid = LookupVariable(b, c, true);
+ }
+ break;
+
+ default:
+ if (!noerror)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper qualified name (too many dotted names): %s",
+ NameListToString(names))));
+ return InvalidOid;
+ }
+
+ /*
+ * If, upon retry, we get back the same OID we did last time, then the
+ * invalidation messages we processed did not change the final answer.
+ * So we're done.
+ *
+ * If we got a different OID, we've locked the variable that used to
+ * have this name rather than the one that does now. So release the
+ * lock.
+ */
+ if (retry)
+ {
+ if (old_varid == varid)
+ break;
+
+ if (OidIsValid(old_varid))
+ UnlockDatabaseObject(VariableRelationId, old_varid, 0, AccessShareLock);
+ }
+
+ /*
+ * Lock the variable. This will also accept any pending invalidation
+ * messages. If we got back InvalidOid, indicating not found, then
+ * there's nothing to lock, but we accept invalidation messages
+ * anyway, to flush any negative catcache entries that may be
+ * lingering.
+ */
+ if (!OidIsValid(varid))
+ AcceptInvalidationMessages();
+ else
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ /*
+ * If no invalidation message were processed, we're done!
+ */
+ if (inval_count == SharedInvalidMessageCounter)
+ break;
+
+ retry = true;
+ old_varid = varid;
+ varid = InvalidOid;
+ }
+
+ return varid;
+}
+
/*
* DeconstructQualifiedName
* Given a possibly-qualified name expressed as a list of String nodes,
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
index 29d967a2d5b..bb445e9434b 100644
--- a/src/backend/catalog/pg_variable.c
+++ b/src/backend/catalog/pg_variable.c
@@ -26,6 +26,7 @@
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
+#include "utils/pg_lsn.h"
#include "utils/syscache.h"
static ObjectAddress create_variable(const char *varName,
@@ -101,6 +102,7 @@ create_variable(const char *varName,
varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varcreate_lsn - 1] = LSNGetDatum(GetXLogInsertRecPtr());
values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile
index cb2fbdc7c60..aee40e7bd59 100644
--- a/src/backend/commands/Makefile
+++ b/src/backend/commands/Makefile
@@ -53,6 +53,7 @@ OBJS = \
schemacmds.o \
seclabel.o \
sequence.o \
+ session_variable.o \
statscmds.o \
subscriptioncmds.o \
tablecmds.o \
diff --git a/src/backend/commands/meson.build b/src/backend/commands/meson.build
index dd4cde41d32..101c8d75dd1 100644
--- a/src/backend/commands/meson.build
+++ b/src/backend/commands/meson.build
@@ -41,6 +41,7 @@ backend_sources += files(
'schemacmds.c',
'seclabel.c',
'sequence.c',
+ 'session_variable.c',
'statscmds.c',
'subscriptioncmds.c',
'tablecmds.c',
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index bf7d2b2309f..56b3d8cb91d 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -342,6 +342,16 @@ EvaluateParams(ParseState *pstate, PreparedStatement *pstmt, List *params,
i++;
}
+ /*
+ * The arguments of EXECUTE are evaluated by a direct expression
+ * executor call. This mode doesn't support session variables yet.
+ * It will be enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
/* Prepare the expressions for execution */
exprstates = ExecPrepareExprList(params, estate);
diff --git a/src/backend/commands/session_variable.c b/src/backend/commands/session_variable.c
new file mode 100644
index 00000000000..d2891a1dcb7
--- /dev/null
+++ b/src/backend/commands/session_variable.c
@@ -0,0 +1,529 @@
+/*-------------------------------------------------------------------------
+ *
+ * session_variable.c
+ * session variable creation/manipulation commands
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/commands/session_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "rewrite/rewriteHandler.h"
+#include "storage/lmgr.h"
+#include "storage/proc.h"
+#include "tcop/tcopprot.h"
+#include "utils/builtins.h"
+#include "utils/datum.h"
+#include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/snapmgr.h"
+#include "utils/syscache.h"
+
+/*
+ * The values of session variables are stored in the backend's private memory
+ * in the dedicated memory context SVariableMemoryContext in binary format.
+ * They are stored in the "sessionvars" hash table, whose key is the OID of the
+ * variable. However, the OID is not good enough to identify a session
+ * variable: concurrent sessions could drop the session variable and create a
+ * new one, which could be assigned the same OID. To ensure that the values
+ * stored in memory and the catalog definition match, we also keep track of
+ * the "create_lsn". Before any access to the variable values, we need to
+ * check if the LSN stored in memory matches the LSN in the catalog. If there
+ * is a mismatch between the LSNs, or if the OID is not present in pg_variable
+ * at all, the value stored in memory is released.
+ */
+typedef struct SVariableData
+{
+ Oid varid; /* pg_variable OID of the variable (hash key) */
+ XLogRecPtr create_lsn;
+
+ bool isnull;
+ Datum value;
+
+ Oid typid;
+ int16 typlen;
+ bool typbyval;
+
+ bool is_domain;
+
+ /*
+ * domain_check_extra holds cached domain metadata. This "extra" is
+ * usually stored in fn_mcxt. We do not have access to that memory context
+ * for session variables, but we can use TopTransactionContext instead.
+ * A fresh value is forced when we detect we are in a different transaction
+ * (the local transaction ID differs from domain_check_extra_lxid).
+ */
+ void *domain_check_extra;
+ LocalTransactionId domain_check_extra_lxid;
+
+ /*
+ * Stored value and type description can be outdated when we receive a
+ * sinval message. We then have to check if the stored data are still
+ * trustworthy.
+ */
+ bool is_valid;
+
+ uint32 hashvalue; /* used for pairing sinval message */
+} SVariableData;
+
+typedef SVariableData *SVariable;
+
+static HTAB *sessionvars = NULL; /* hash table for session variables */
+
+static MemoryContext SVariableMemoryContext = NULL;
+
+/*
+ * Callback function for session variable invalidation.
+ */
+static void
+pg_variable_cache_callback(Datum arg, int cacheid, uint32 hashvalue)
+{
+ HASH_SEQ_STATUS status;
+ SVariable svar;
+
+ elog(DEBUG1, "pg_variable_cache_callback %u %u", cacheid, hashvalue);
+
+ Assert(sessionvars);
+
+ /*
+ * If the hashvalue is not specified, we have to recheck all currently
+ * used session variables. Since we can't tell the exact session variable
+ * from its hashvalue, we have to iterate over all items in the hash bucket.
+ */
+ hash_seq_init(&status, sessionvars);
+
+ while ((svar = (SVariable) hash_seq_search(&status)) != NULL)
+ {
+ if (hashvalue == 0 || svar->hashvalue == hashvalue)
+ {
+ svar->is_valid = false;
+ }
+ }
+}
+
+/*
+ * Release stored value, free memory
+ */
+static void
+free_session_variable_value(SVariable svar)
+{
+ /* clean the current value */
+ if (!svar->isnull)
+ {
+ if (!svar->typbyval)
+ pfree(DatumGetPointer(svar->value));
+
+ svar->isnull = true;
+ }
+
+ svar->value = (Datum) 0;
+}
+
+/*
+ * Returns true when the entry in pg_variable is consistent with the given
+ * session variable.
+ */
+static bool
+is_session_variable_valid(SVariable svar)
+{
+ HeapTuple tp;
+ bool result = false;
+
+ Assert(OidIsValid(svar->varid));
+
+ tp = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(svar->varid));
+
+ if (HeapTupleIsValid(tp))
+ {
+ /*
+ * The OID alone is not enough as an unique identifier, because OID
+ * values get recycled, and a new session variable could have got
+ * the same OID. We do a second check against the 64-bit LSN when
+ * the variable was created.
+ */
+ if (svar->create_lsn == ((Form_pg_variable) GETSTRUCT(tp))->varcreate_lsn)
+ result = true;
+
+ ReleaseSysCache(tp);
+ }
+
+ return result;
+}
+
+/*
+ * Initialize attributes cached in "svar"
+ */
+static void
+setup_session_variable(SVariable svar, Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ Assert(OidIsValid(varid));
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ svar->varid = varid;
+ svar->create_lsn = varform->varcreate_lsn;
+
+ svar->typid = varform->vartype;
+
+ get_typlenbyval(svar->typid, &svar->typlen, &svar->typbyval);
+
+ svar->is_domain = (get_typtype(varform->vartype) == TYPTYPE_DOMAIN);
+ svar->domain_check_extra = NULL;
+ svar->domain_check_extra_lxid = InvalidLocalTransactionId;
+
+ svar->isnull = true;
+ svar->value = (Datum) 0;
+
+ svar->is_valid = true;
+
+ svar->hashvalue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ ReleaseSysCache(tup);
+}
+
+/*
+ * Assign a new value to the session variable. It is copied to
+ * SVariableMemoryContext if necessary.
+ *
+ * If any error happens, the existing value won't be modified.
+ */
+static void
+set_session_variable(SVariable svar, Datum value, bool isnull)
+{
+ Datum newval;
+ SVariableData locsvar,
+ *_svar;
+
+ Assert(svar);
+ Assert(!isnull || value == (Datum) 0);
+
+ /*
+ * Use typbyval, typbylen from session variable only when they are
+ * trustworthy (the invalidation message was not accepted for this
+ * variable). If the variable might be invalid, force setup.
+ *
+ * Do not overwrite the passed session variable until we can be certain
+ * that no error can be thrown.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(&locsvar, svar->varid);
+ _svar = &locsvar;
+ }
+ else
+ _svar = svar;
+
+ if (!isnull)
+ {
+ MemoryContext oldcxt = MemoryContextSwitchTo(SVariableMemoryContext);
+
+ newval = datumCopy(value, _svar->typbyval, _svar->typlen);
+
+ MemoryContextSwitchTo(oldcxt);
+ }
+ else
+ newval = value;
+
+ free_session_variable_value(svar);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has new value",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ svar->varid);
+
+ /* no more error expected, so we can overwrite the old variable now */
+ if (svar != _svar)
+ memcpy(svar, _svar, sizeof(SVariableData));
+
+ svar->value = newval;
+ svar->isnull = isnull;
+}
+
+/*
+ * Create the hash table for storing session variables.
+ */
+static void
+create_sessionvars_hashtables(void)
+{
+ HASHCTL vars_ctl;
+
+ Assert(!sessionvars);
+
+ if (!SVariableMemoryContext)
+ {
+ /* read sinval messages */
+ CacheRegisterSyscacheCallback(VARIABLEOID,
+ pg_variable_cache_callback,
+ (Datum) 0);
+
+ /* we need our own long-lived memory context */
+ SVariableMemoryContext =
+ AllocSetContextCreate(TopMemoryContext,
+ "session variables",
+ ALLOCSET_START_SMALL_SIZES);
+ }
+
+ memset(&vars_ctl, 0, sizeof(vars_ctl));
+ vars_ctl.keysize = sizeof(Oid);
+ vars_ctl.entrysize = sizeof(SVariableData);
+ vars_ctl.hcxt = SVariableMemoryContext;
+
+ sessionvars = hash_create("Session variables", 64, &vars_ctl,
+ HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+}
+
+/*
+ * Search a session variable in the hash table given its OID. If it
+ * doesn't exist, then insert it there.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the
+ * session variable until the end of the transaction.
+ */
+static SVariable
+get_session_variable(Oid varid)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect the used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (found)
+ {
+ if (!svar->is_valid)
+ {
+ /*
+ * If there was an invalidation message, the variable might still be
+ * valid, but we have to check with the system catalog.
+ */
+ if (is_session_variable_valid(svar))
+ svar->is_valid = true;
+ else
+ /* if the value cannot be validated, we have to discard it */
+ free_session_variable_value(svar);
+ }
+ }
+ else
+ svar->is_valid = false;
+
+ /*
+ * Force setup for not yet initialized variables or variables that cannot
+ * be validated.
+ */
+ if (!svar->is_valid)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by READ)",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ varid);
+ }
+
+ /* ensure the returned data is still of the correct domain */
+ if (svar->is_domain)
+ {
+ /*
+ * Store "extra" for domain_check() in TopTransactionContext. When we
+ * are in a new transaction, domain_check_extra cache is not valid any
+ * more.
+ */
+ if (svar->domain_check_extra_lxid != MyProc->vxid.lxid)
+ svar->domain_check_extra = NULL;
+
+ domain_check(svar->value, svar->isnull,
+ svar->typid, &svar->domain_check_extra,
+ TopTransactionContext);
+
+ svar->domain_check_extra_lxid = MyProc->vxid.lxid;
+ }
+
+ return svar;
+}
+
+/*
+ * Store the given value in a session variable in the cache.
+ *
+ * The caller is responsible for doing permission checks.
+ *
+ * As a side effect, this function acquires a AccessShareLock on the session
+ * variable until the end of the transaction.
+ */
+void
+SetSessionVariable(Oid varid, Datum value, bool isNull)
+{
+ SVariable svar;
+ bool found;
+
+ /* protect used session variable against DROP */
+ LockDatabaseObject(VariableRelationId, varid, 0, AccessShareLock);
+
+ if (!sessionvars)
+ create_sessionvars_hashtables();
+
+ svar = (SVariable) hash_search(sessionvars, &varid,
+ HASH_ENTER, &found);
+
+ if (!found)
+ {
+ setup_session_variable(svar, varid);
+
+ elog(DEBUG1, "session variable \"%s.%s\" (oid:%u) has assigned entry in memory (emitted by WRITE)",
+ get_namespace_name(get_session_variable_namespace(svar->varid)),
+ get_session_variable_name(svar->varid),
+ varid);
+ }
+
+ /* if this fails, it won't change the stored value */
+ set_session_variable(svar, value, isNull);
+}
+
+/*
+ * Returns a copy of the value stored in a variable.
+ */
+static inline Datum
+copy_session_variable_value(SVariable svar, bool *isNull)
+{
+ Datum value;
+
+ /* force copy of non NULL value */
+ if (!svar->isnull)
+ {
+ value = datumCopy(svar->value, svar->typbyval, svar->typlen);
+ *isNull = false;
+ }
+ else
+ {
+ value = (Datum) 0;
+ *isNull = true;
+ }
+
+ return value;
+}
+
+/*
+ * Returns a copy of the value of the session variable (in the current memory
+ * context). The caller is responsible for permission checks.
+ */
+Datum
+GetSessionVariable(Oid varid, bool *isNull)
+{
+ SVariable svar;
+
+ svar = get_session_variable(varid);
+
+ /*
+ * Although "svar" is freshly validated in this point, svar->is_valid can
+ * be false, if an invalidation message was processed during the domain check.
+ * But the variable and all its dependencies are locked now, so we don't need
+ * to repeat the validation.
+ */
+ return copy_session_variable_value(svar, isNull);
+}
+
+/*
+ * Assign the result of the evaluated expression to the session variable
+ */
+void
+ExecuteLetStmt(ParseState *pstate,
+ LetStmt *stmt,
+ ParamListInfo params,
+ QueryEnvironment *queryEnv,
+ QueryCompletion *qc)
+{
+ Query *query = castNode(Query, stmt->query);
+ List *rewritten;
+ DestReceiver *dest;
+ AclResult aclresult;
+ PlannedStmt *plan;
+ QueryDesc *queryDesc;
+ Oid varid = query->resultVariable;
+
+ Assert(OidIsValid(varid));
+
+ /* do we have permission to write to the session variable? */
+ aclresult = object_aclcheck(VariableRelationId, varid, GetUserId(), ACL_UPDATE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE, get_session_variable_name(varid));
+
+ /* create a dest receiver for LET */
+ dest = CreateVariableDestReceiver(varid);
+
+ /* run the query rewriter */
+ query = copyObject(query);
+
+ rewritten = QueryRewrite(query);
+
+ Assert(list_length(rewritten) == 1);
+
+ query = linitial_node(Query, rewritten);
+ Assert(query->commandType == CMD_SELECT);
+
+ /* plan the query */
+ plan = pg_plan_query(query, pstate->p_sourcetext,
+ CURSOR_OPT_PARALLEL_OK, params);
+
+ /*
+ * Use a snapshot with an updated command ID to ensure this query sees the
+ * results of any previously executed queries. (This could only matter if
+ * the planner executed an allegedly-stable function that changed the
+ * database contents, but let's do it anyway to be parallel to the EXPLAIN
+ * code path.)
+ */
+ PushCopiedSnapshot(GetActiveSnapshot());
+ UpdateActiveSnapshotCommandId();
+
+ /* create a QueryDesc, redirecting output to our tuple receiver */
+ queryDesc = CreateQueryDesc(plan, NULL, pstate->p_sourcetext,
+ GetActiveSnapshot(), InvalidSnapshot,
+ dest, params, queryEnv, 0);
+
+ /* call ExecutorStart to prepare the plan for execution */
+ ExecutorStart(queryDesc, 0);
+
+ /*
+ * Run the plan to completion. The result should be only one row. To
+ * check if there are too many result rows, we try to fetch two.
+ */
+ ExecutorRun(queryDesc, ForwardScanDirection, 2L);
+
+ /* save the rowcount if we're given a QueryCompletion to fill */
+ if (qc)
+ SetQueryCompletion(qc, CMDTAG_LET, queryDesc->estate->es_processed);
+
+ /* and clean up */
+ ExecutorFinish(queryDesc);
+ ExecutorEnd(queryDesc);
+
+ FreeQueryDesc(queryDesc);
+
+ PopActiveSnapshot();
+}
diff --git a/src/backend/executor/Makefile b/src/backend/executor/Makefile
index 11118d0ce02..71248a34f26 100644
--- a/src/backend/executor/Makefile
+++ b/src/backend/executor/Makefile
@@ -76,6 +76,7 @@ OBJS = \
nodeWindowAgg.o \
nodeWorktablescan.o \
spi.o \
+ svariableReceiver.o \
tqueue.o \
tstoreReceiver.o
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index f1569879b52..e4e9de335b5 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -1041,6 +1041,38 @@ ExecInitExprRec(Expr *node, ExprState *state,
scratch.d.param.paramtype = param->paramtype;
ExprEvalPushStep(state, &scratch);
break;
+
+ case PARAM_VARIABLE:
+ {
+ int es_num_session_variables = 0;
+ SessionVariableValue *es_session_variables = NULL;
+ SessionVariableValue *var;
+
+ if (state->parent && state->parent->state)
+ {
+ es_session_variables = state->parent->state->es_session_variables;
+ es_num_session_variables = state->parent->state->es_num_session_variables;
+ }
+
+ Assert(es_session_variables);
+
+ /* parameter sanity checks */
+ if (param->paramid >= es_num_session_variables)
+ elog(ERROR, "paramid of PARAM_VARIABLE param is out of range");
+
+ var = &es_session_variables[param->paramid];
+
+ /*
+ * In this case, pass the value like a
+ * constant.
+ */
+ scratch.opcode = EEOP_CONST;
+ scratch.d.constval.value = var->value;
+ scratch.d.constval.isnull = var->isnull;
+ ExprEvalPushStep(state, &scratch);
+ }
+ break;
+
case PARAM_EXTERN:
/*
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 7230f968101..a9d31b085fd 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -43,7 +43,9 @@
#include "access/xact.h"
#include "catalog/namespace.h"
#include "catalog/partition.h"
+#include "catalog/pg_variable.h"
#include "commands/matview.h"
+#include "commands/session_variable.h"
#include "commands/trigger.h"
#include "executor/executor.h"
#include "executor/execPartition.h"
@@ -206,6 +208,70 @@ standard_ExecutorStart(QueryDesc *queryDesc, int eflags)
Assert(queryDesc->sourceText != NULL);
estate->es_sourceText = queryDesc->sourceText;
+ /*
+ * The executor doesn't work with session variables directly. Values of
+ * related session variables are copied to a dedicated array, and this array
+ * is passed to the executor. This array is stable "snapshot" of values of
+ * used session variables. There are three benefits of this strategy:
+ *
+ * - consistency with external parameters and plpgsql variables,
+ *
+ * - session variables can be parallel safe,
+ *
+ * - we don't need make fresh copy for any read of session variable
+ * (this is necessary because the internally the session variable can
+ * be changed inside query execution time, and then a reference to
+ * previously returned value can be corrupted).
+ */
+ if (queryDesc->plannedstmt->sessionVariables)
+ {
+ int nSessionVariables;
+ int i = 0;
+
+ /*
+ * In this case, the query uses session variables, but we have to
+ * prepare the array with passed values (of used session variables)
+ * first.
+ */
+ Assert(!IsParallelWorker());
+ nSessionVariables = list_length(queryDesc->plannedstmt->sessionVariables);
+
+ /* create the array used for passing values of used session variables */
+ estate->es_session_variables = (SessionVariableValue *)
+ palloc(nSessionVariables * sizeof(SessionVariableValue));
+
+ /* fill the array */
+ foreach_oid(varid, queryDesc->plannedstmt->sessionVariables)
+ {
+ /*
+ * Permission check should be executed on all explicitly used
+ * variables in the query. For implicitly used variable
+ * (like base node of assignment indirect) we cannot do permission
+ * check, because we need read the value (and user can have
+ * only UPDATE variable). In this case the permission check
+ * is executed in write time.
+ */
+ if (varid != queryDesc->plannedstmt->exclSelectPermCheckVarid)
+ {
+ AclResult aclresult;
+
+ aclresult = object_aclcheck(VariableRelationId, varid,
+ GetUserId(), ACL_SELECT);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error(aclresult, OBJECT_VARIABLE,
+ get_session_variable_name(varid));
+ }
+
+ estate->es_session_variables[i].value =
+ GetSessionVariable(varid,
+ &estate->es_session_variables[i].isnull);
+
+ i++;
+ }
+
+ estate->es_num_session_variables = nSessionVariables;
+ }
+
/*
* Fill in the query environment, if any, from queryDesc.
*/
diff --git a/src/backend/executor/meson.build b/src/backend/executor/meson.build
index 2cea41f8771..491092fcc4c 100644
--- a/src/backend/executor/meson.build
+++ b/src/backend/executor/meson.build
@@ -64,6 +64,7 @@ backend_sources += files(
'nodeWindowAgg.c',
'nodeWorktablescan.c',
'spi.c',
+ 'svariableReceiver.c',
'tqueue.c',
'tstoreReceiver.c',
)
diff --git a/src/backend/executor/svariableReceiver.c b/src/backend/executor/svariableReceiver.c
new file mode 100644
index 00000000000..c6163fb36f6
--- /dev/null
+++ b/src/backend/executor/svariableReceiver.c
@@ -0,0 +1,172 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.c
+ * An implementation of DestReceiver that stores the result value in
+ * a session variable.
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/executor/svariableReceiver.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+#include "miscadmin.h"
+
+#include "access/detoast.h"
+#include "catalog/pg_variable.h"
+#include "commands/session_variable.h"
+#include "executor/svariableReceiver.h"
+#include "storage/lock.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+/*
+ * This DestReceiver is used by the LET command for storing the result to a
+ * session variable. The result has to have only one tuple with only one
+ * non-deleted attribute. The row counter (field "rows") is incremented
+ * after receiving a row, and an error is raised when there are no rows or
+ * there are more than one received rows. A received tuple cannot to have
+ * deleted attributes. The value is detoasted before storing it in the
+ * session variable.
+ */
+typedef struct
+{
+ DestReceiver pub;
+ Oid varid;
+ bool need_detoast; /* do we need to detoast the attribute? */
+ int rows; /* row counter */
+} SVariableState;
+
+/*
+ * Prepare to receive tuples from executor.
+ */
+static void
+svariableStartupReceiver(DestReceiver *self, int operation, TupleDesc typeinfo)
+{
+ SVariableState *myState = (SVariableState *) self;
+ LOCKTAG locktag PG_USED_FOR_ASSERTS_ONLY;
+ Form_pg_attribute attr;
+ Oid typid PG_USED_FOR_ASSERTS_ONLY;
+ Oid collid PG_USED_FOR_ASSERTS_ONLY;
+ int32 typmod PG_USED_FOR_ASSERTS_ONLY;
+
+ Assert(myState->pub.mydest == DestVariable);
+ Assert(OidIsValid(myState->varid));
+ Assert(SearchSysCacheExists1(VARIABLEOID, myState->varid));
+ Assert(typeinfo->natts == 1);
+
+#ifdef USE_ASSERT_CHECKING
+
+ SET_LOCKTAG_OBJECT(locktag,
+ MyDatabaseId,
+ VariableRelationId,
+ myState->varid,
+ 0);
+
+ Assert(LockHeldByMe(&locktag, AccessShareLock, false));
+
+#endif
+
+ attr = TupleDescAttr(typeinfo, 0);
+
+ Assert(!attr->attisdropped);
+
+#ifdef USE_ASSERT_CHECKING
+
+ get_session_variable_type_typmod_collid(myState->varid,
+ &typid,
+ &typmod,
+ &collid);
+
+ Assert(attr->atttypid == typid);
+ Assert(attr->atttypmod < 0 || attr->atttypmod == typmod);
+
+#endif
+
+ myState->need_detoast = attr->attlen == -1;
+ myState->rows = 0;
+}
+
+/*
+ * Receive a tuple from the executor and store it in the session variable.
+ */
+static bool
+svariableReceiveSlot(TupleTableSlot *slot, DestReceiver *self)
+{
+ SVariableState *myState = (SVariableState *) self;
+ Datum value;
+ bool isnull;
+ bool freeval = false;
+
+ /* make sure the tuple is fully deconstructed */
+ slot_getallattrs(slot);
+
+ value = slot->tts_values[0];
+ isnull = slot->tts_isnull[0];
+
+ if (myState->need_detoast && !isnull && VARATT_IS_EXTERNAL(DatumGetPointer(value)))
+ {
+ value = PointerGetDatum(detoast_external_attr((struct varlena *)
+ DatumGetPointer(value)));
+ freeval = true;
+ }
+
+ myState->rows += 1;
+
+ if (myState->rows > 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_TOO_MANY_ROWS),
+ errmsg("expression returned more than one row")));
+
+ SetSessionVariable(myState->varid, value, isnull);
+
+ if (freeval)
+ pfree(DatumGetPointer(value));
+
+ return true;
+}
+
+/*
+ * Clean up at end of the executor run
+ */
+static void
+svariableShutdownReceiver(DestReceiver *self)
+{
+ if (((SVariableState *) self)->rows == 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_NO_DATA_FOUND),
+ errmsg("expression returned no rows")));
+}
+
+/*
+ * Destroy the receiver when we are done with it
+ */
+static void
+svariableDestroyReceiver(DestReceiver *self)
+{
+ pfree(self);
+}
+
+/*
+ * Initially create a DestReceiver object.
+ */
+DestReceiver *
+CreateVariableDestReceiver(Oid varid)
+{
+ SVariableState *self = (SVariableState *) palloc0(sizeof(SVariableState));
+
+ self->pub.receiveSlot = svariableReceiveSlot;
+ self->pub.rStartup = svariableStartupReceiver;
+ self->pub.rShutdown = svariableShutdownReceiver;
+ self->pub.rDestroy = svariableDestroyReceiver;
+ self->pub.mydest = DestVariable;
+
+ self->varid = varid;
+
+ return (DestReceiver *) self;
+}
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 7bc823507f1..d8fc3d9fa69 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4375,6 +4375,16 @@ raw_expression_tree_walker_impl(Node *node,
return true;
}
break;
+ case T_LetStmt:
+ {
+ LetStmt *stmt = (LetStmt *) node;
+
+ if (WALK(stmt->target))
+ return true;
+ if (WALK(stmt->query))
+ return true;
+ }
+ break;
case T_PLAssignStmt:
{
PLAssignStmt *stmt = (PLAssignStmt *) node;
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 49ad6e83578..c8ca43afa71 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -343,6 +343,21 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
glob->transientPlan = false;
glob->dependsOnRole = false;
glob->partition_directory = NULL;
+ glob->sessionVariables = NIL;
+
+ /*
+ * The (session) result variable should be stored to global, because
+ * it is not set in subquery. When this variable is used other than
+ * in base node of assignment indirection, we need to check the access
+ * rights (and then we need to detect this situation). The variable used
+ * like base node cannot be different than target (result) variable.
+ * Because we know the result variable before planner invocation, we
+ * can simply search of usage just this variable, and we don't need to
+ * to wait until the end of planning when we know basenodeSessionVarid.
+ */
+ glob->resultVariable = parse->resultVariable;
+ glob->basenodeSessionVarid = InvalidOid;
+ glob->basenodeSessionVarSelectCheck = false;
/*
* Assess whether it's feasible to use parallel mode for this query. We
@@ -581,6 +596,20 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
result->paramExecTypes = glob->paramExecTypes;
/* utilityStmt should be null, but we might as well copy it */
result->utilityStmt = parse->utilityStmt;
+
+ result->sessionVariables = glob->sessionVariables;
+
+ /*
+ * The session variable used (and only used) like base node
+ * for assignemnt indirection should be excluded from permission
+ * check.
+ */
+ if (OidIsValid(glob->basenodeSessionVarid) &&
+ (!glob->basenodeSessionVarSelectCheck))
+ result->exclSelectPermCheckVarid = glob->basenodeSessionVarid;
+ else
+ result->exclSelectPermCheckVarid = InvalidOid;
+
result->stmt_location = parse->stmt_location;
result->stmt_len = parse->stmt_len;
@@ -759,6 +788,13 @@ subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root,
*/
pull_up_subqueries(root);
+ /*
+ * Check if some subquery uses a session variable. The flag
+ * hasSessionVariables should be true if the query or some subquery uses a
+ * session variable.
+ */
+ pull_up_has_session_variables(root);
+
/*
* If this is a simple UNION ALL query, flatten it into an appendrel. We
* do this now because it requires applying pull_up_subqueries to the leaf
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 150e9f060ee..d071bd0c559 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -210,6 +210,9 @@ static List *set_returning_clause_references(PlannerInfo *root,
static List *set_windowagg_runcondition_references(PlannerInfo *root,
List *runcondition,
Plan *plan);
+static bool pull_up_has_session_variables_walker(Node *node,
+ PlannerInfo *root);
+static void record_plan_variable_dependency(PlannerInfo *root, Oid varid);
/*****************************************************************************
@@ -1318,6 +1321,50 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
return plan;
}
+/*
+ * Search usage of session variables in subqueries
+ */
+void
+pull_up_has_session_variables(PlannerInfo *root)
+{
+ Query *query = root->parse;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ }
+ else
+ {
+ (void) query_tree_walker(query,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+}
+
+static bool
+pull_up_has_session_variables_walker(Node *node, PlannerInfo *root)
+{
+ if (node == NULL)
+ return false;
+ if (IsA(node, Query))
+ {
+ Query *query = (Query *) node;
+
+ if (query->hasSessionVariables)
+ {
+ root->hasSessionVariables = true;
+ return false;
+ }
+
+ /* recurse into subselects */
+ return query_tree_walker((Query *) node,
+ pull_up_has_session_variables_walker,
+ (void *) root, 0);
+ }
+ return expression_tree_walker(node, pull_up_has_session_variables_walker,
+ (void *) root);
+}
+
/*
* set_indexonlyscan_references
* Do set_plan_references processing on an IndexOnlyScan
@@ -2018,8 +2065,9 @@ copyVar(Var *var)
* This is code that is common to all variants of expression-fixing.
* We must look up operator opcode info for OpExpr and related nodes,
* add OIDs from regclass Const nodes into root->glob->relationOids, and
- * add PlanInvalItems for user-defined functions into root->glob->invalItems.
- * We also fill in column index lists for GROUPING() expressions.
+ * add PlanInvalItems for user-defined functions and session variables into
+ * root->glob->invalItems. We also fill in column index lists for GROUPING()
+ * expressions.
*
* We assume it's okay to update opcode info in-place. So this could possibly
* scribble on the planner's input data structures, but it's OK.
@@ -2109,6 +2157,13 @@ fix_expr_common(PlannerInfo *root, Node *node)
g->cols = cols;
}
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ record_plan_variable_dependency(root, p->paramvarid);
+ }
}
/*
@@ -2118,6 +2173,10 @@ fix_expr_common(PlannerInfo *root, Node *node)
* If it's a PARAM_MULTIEXPR, replace it with the appropriate Param from
* root->multiexpr_params; otherwise no change is needed.
* Just for paranoia's sake, we make a copy of the node in either case.
+ *
+ * If it's a PARAM_VARIABLE, then we collect used session variables in
+ * the list root->glob->sessionVariable. Also, assign the parameter's
+ * "paramid" to the parameter's position in that list.
*/
static Node *
fix_param_node(PlannerInfo *root, Param *p)
@@ -2136,6 +2195,62 @@ fix_param_node(PlannerInfo *root, Param *p)
elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid);
return copyObject(list_nth(params, colno - 1));
}
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ int n = 0;
+ bool found = false;
+
+ /* we will modify object */
+ p = (Param *) copyObject(p);
+
+ /*
+ * Now, we can actualize list of session variables, and we can
+ * complete paramid parameter.
+ */
+ foreach_oid(varid, root->glob->sessionVariables)
+ {
+ if (varid == p->paramvarid)
+ {
+ p->paramid = n;
+ found = true;
+ break;
+ }
+ n += 1;
+ }
+
+ if (!found)
+ {
+ root->glob->sessionVariables = lappend_oid(root->glob->sessionVariables,
+ p->paramvarid);
+ p->paramid = n;
+ }
+
+ /*
+ * We do SELECT permission check of all variables used by
+ * the query excluding the variable that is used only as base node
+ * of assignment indirection. The variable id assigned to this param
+ * should be same like resultVariable id, and this param should be
+ * used only once in query. When the variable is referenced by any
+ * other param, we should to do SELECT permission check for this variable
+ * too.
+ */
+ if (p->parambasenode)
+ {
+ Assert(!OidIsValid(root->glob->basenodeSessionVarid));
+ Assert(root->glob->resultVariable == p->paramvarid);
+
+ root->glob->basenodeSessionVarid = p->paramvarid;
+ }
+ else
+ {
+ if (p->paramvarid == root->glob->resultVariable)
+ root->glob->basenodeSessionVarSelectCheck = true;
+ }
+
+ return (Node *) p;
+ }
+
return (Node *) copyObject(p);
}
@@ -2197,7 +2312,10 @@ fix_alternative_subplan(PlannerInfo *root, AlternativeSubPlan *asplan,
* replacing Aggref nodes that should be replaced by initplan output Params,
* choosing the best implementation for AlternativeSubPlans,
* looking up operator opcode info for OpExpr and related nodes,
- * and adding OIDs from regclass Const nodes into root->glob->relationOids.
+ * adding OIDs from regclass Const nodes into root->glob->relationOids,
+ * assigning paramvarid to PARAM_VARIABLE params, and collecting the
+ * OIDs of session variables in the root->glob->sessionVariables list
+ * (paramvarid is the position of the session variable in this list).
*
* 'node': the expression to be modified
* 'rtoffset': how much to increment varnos by
@@ -2219,7 +2337,8 @@ fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec)
root->multiexpr_params != NIL ||
root->glob->lastPHId != 0 ||
root->minmax_aggs != NIL ||
- root->hasAlternativeSubPlans)
+ root->hasAlternativeSubPlans ||
+ root->hasSessionVariables)
{
return fix_scan_expr_mutator(node, &context);
}
@@ -3612,6 +3731,25 @@ record_plan_type_dependency(PlannerInfo *root, Oid typid)
}
}
+/*
+ * Record dependency on a session variable. The variable can be used as a
+ * session variable in an expression list, or as the target of a LET statement.
+ */
+static void
+record_plan_variable_dependency(PlannerInfo *root, Oid varid)
+{
+ PlanInvalItem *inval_item = makeNode(PlanInvalItem);
+
+ /* paramid is still session variable id */
+ inval_item->cacheId = VARIABLEOID;
+ inval_item->hashValue = GetSysCacheHashValue1(VARIABLEOID,
+ ObjectIdGetDatum(varid));
+
+ /* append this variable to global, register dependency */
+ root->glob->invalItems = lappend(root->glob->invalItems,
+ inval_item);
+}
+
/*
* extract_query_dependencies
* Given a rewritten, but not yet planned, query or queries
@@ -3697,9 +3835,9 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
}
/*
- * Ignore other utility statements, except those (such as EXPLAIN)
- * that contain a parsed-but-not-planned query. For those, we
- * just need to transfer our attention to the contained query.
+ * Ignore other utility statements, except those (such as EXPLAIN
+ * or LET) that contain a parsed-but-not-planned query. For those,
+ * we just need to transfer our attention to the contained query.
*/
query = UtilityContainsQuery(query->utilityStmt);
if (query == NULL)
@@ -3722,6 +3860,10 @@ extract_query_dependencies_walker(Node *node, PlannerInfo *context)
lappend_oid(context->glob->relationOids, rte->relid);
}
+ /* record dependency on the target variable of a LET command */
+ if (OidIsValid(query->resultVariable))
+ record_plan_variable_dependency(context, query->resultVariable);
+
/* And recurse into the query's subexpressions */
return query_tree_walker(query, extract_query_dependencies_walker,
context, 0);
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index 87dc6f56b57..1ebc808a5e6 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -1585,6 +1585,9 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
/* If subquery had any RLS conditions, now main query does too */
parse->hasRowSecurity |= subquery->hasRowSecurity;
+ /* if the subquery had session variables, the main query does too */
+ parse->hasSessionVariables |= subquery->hasSessionVariables;
+
/*
* subquery won't be pulled up if it hasAggs, hasWindowFuncs, or
* hasTargetSRFs, so no work needed on those flags
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 26a3e050086..23cafc73c3b 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -24,6 +24,7 @@
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "commands/session_variable.h"
#include "executor/executor.h"
#include "executor/functions.h"
#include "funcapi.h"
@@ -936,6 +937,13 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context)
if (param->paramkind == PARAM_EXTERN)
return false;
+ /* we don't support passing session variables to workers */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
+ return true;
+ }
+
if (param->paramkind != PARAM_EXEC ||
!list_member_int(context->safe_param_ids, param->paramid))
{
@@ -2391,6 +2399,7 @@ convert_saop_to_hashed_saop_walker(Node *node, void *context)
* value of the Param.
* 2. Fold stable, as well as immutable, functions to constants.
* 3. Reduce PlaceHolderVar nodes to their contained expressions.
+ * 4. Current value of session variable can be used for estimation too.
*--------------------
*/
Node *
@@ -2517,6 +2526,27 @@ eval_const_expressions_mutator(Node *node,
}
}
}
+ else if (param->paramkind == PARAM_VARIABLE &&
+ context->estimate)
+ {
+ int16 typLen;
+ bool typByVal;
+ Datum pval;
+ bool isnull;
+
+ get_typlenbyval(param->paramtype,
+ &typLen, &typByVal);
+
+ pval = GetSessionVariable(param->paramvarid, &isnull);
+
+ return (Node *) makeConst(param->paramtype,
+ param->paramtypmod,
+ param->paramcollid,
+ (int) typLen,
+ pval,
+ isnull,
+ typByVal);
+ }
/*
* Not replaceable, so just copy the Param (no need to
@@ -4722,7 +4752,8 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
querytree->limitOffset ||
querytree->limitCount ||
querytree->setOperations ||
- list_length(querytree->targetList) != 1)
+ (list_length(querytree->targetList) != 1) ||
+ querytree->hasSessionVariables)
goto fail;
/* If the function result is composite, resolve it */
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 1f4d6adda52..3df219f98d2 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -25,9 +25,12 @@
#include "postgres.h"
#include "access/sysattr.h"
+#include "catalog/namespace.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
+#include "commands/session_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
@@ -51,6 +54,7 @@
#include "utils/backend_status.h"
#include "utils/builtins.h"
#include "utils/guc.h"
+#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/syscache.h"
@@ -83,6 +87,8 @@ static Query *transformCreateTableAsStmt(ParseState *pstate,
CreateTableAsStmt *stmt);
static Query *transformCallStmt(ParseState *pstate,
CallStmt *stmt);
+static Query *transformLetStmt(ParseState *pstate,
+ LetStmt *stmt);
static void transformLockingClause(ParseState *pstate, Query *qry,
LockingClause *lc, bool pushedDown);
#ifdef DEBUG_NODE_TESTS_ENABLED
@@ -414,6 +420,7 @@ transformStmt(ParseState *pstate, Node *parseTree)
case T_UpdateStmt:
case T_DeleteStmt:
case T_MergeStmt:
+ case T_LetStmt:
(void) test_raw_expression_coverage(parseTree, NULL);
break;
default:
@@ -493,6 +500,11 @@ transformStmt(ParseState *pstate, Node *parseTree)
(CallStmt *) parseTree);
break;
+ case T_LetStmt:
+ result = transformLetStmt(pstate,
+ (LetStmt *) parseTree);
+ break;
+
default:
/*
@@ -545,6 +557,7 @@ stmt_requires_parse_analysis(RawStmt *parseTree)
case T_SelectStmt:
case T_ReturnStmt:
case T_PLAssignStmt:
+ case T_LetStmt:
result = true;
break;
@@ -692,6 +705,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1117,6 +1131,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -1582,6 +1597,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, stmt->lockingClause)
{
@@ -1808,12 +1824,241 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
return qry;
}
+/*
+ * transformLetStmt -
+ * transform an Let Statement
+ */
+static Query *
+transformLetStmt(ParseState *pstate, LetStmt *stmt)
+{
+ Query *query;
+ Query *result;
+ List *exprList = NIL;
+ List *exprListCoer = NIL;
+ ListCell *lc;
+ ListCell *indirection_head = NULL;
+ Query *selectQuery;
+ Oid varid;
+ char *attrname = NULL;
+ bool not_unique;
+ bool is_rowtype;
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+ List *names = NULL;
+ int indirection_start;
+ int i = 0;
+
+ /* there can't be any outer WITH to worry about */
+ Assert(pstate->p_ctenamespace == NIL);
+
+ names = NamesFromList(stmt->target);
+
+ /* locks the variable with an AccessShareLock */
+ varid = IdentifyVariable(names, &attrname, ¬_unique, false);
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("target \"%s\" of LET command is ambiguous",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ if (!OidIsValid(varid))
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" doesn't exist",
+ NameListToString(names)),
+ parser_errposition(pstate, stmt->location)));
+
+ /*
+ * Calculate start of possible position of an indirection in list, and
+ * when it is inside the list, store pointer on first node of indirection.
+ */
+ indirection_start = list_length(names) - (attrname ? 1 : 0);
+ if (list_length(stmt->target) > indirection_start)
+ indirection_head = list_nth_cell(stmt->target, indirection_start);
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod, &collid);
+
+ is_rowtype = type_is_rowtype(typid);
+
+ if (attrname && !is_rowtype)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("cannot assign to field \"%s\" of session variable \"%s.%s\" because its type %s is not a composite type",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->location)));
+
+ pstate->p_expr_kind = EXPR_KIND_LET_TARGET;
+
+ /* we need to postpone conversion of "unknown" to text */
+ pstate->p_resolve_unknowns = false;
+
+ selectQuery = transformStmt(pstate, stmt->query);
+
+ /* the grammar should have produced a SELECT */
+ Assert(IsA(selectQuery, Query) && selectQuery->commandType == CMD_SELECT);
+
+ /*
+ * Generate an expression list for the LET that selects all the non-resjunk
+ * columns from the subquery.
+ */
+ exprList = NIL;
+ foreach_node(TargetEntry, tle, selectQuery->targetList)
+ {
+ if (tle->resjunk)
+ continue;
+
+ exprList = lappend(exprList, tle->expr);
+ }
+
+ /* don't allow multicolumn result */
+ if (list_length(exprList) != 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg_plural("assignment expression returned %d column",
+ "assignment expression returned %d columns",
+ list_length(exprList),
+ list_length(exprList)),
+ parser_errposition(pstate,
+ exprLocation((Node *) exprList))));
+
+ exprListCoer = NIL;
+
+ foreach(lc, exprList)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ Expr *coerced_expr;
+ Oid exprtypid;
+
+ /* now we can read the type of the expression */
+ exprtypid = exprType((Node *) expr);
+
+ if (indirection_head)
+ {
+ bool targetIsArray;
+ char *targetName;
+ Param *param;
+
+ targetName = get_session_variable_name(varid);
+ targetIsArray = OidIsValid(get_element_type(typid));
+
+ pstate->p_hasSessionVariables = true;
+
+ param = makeNode(Param);
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+
+ /*
+ * The parameter used as basenode has to have special
+ * mark, because requires special access when we do
+ * SELECT access check.
+ */
+ param->parambasenode = true;
+
+ coerced_expr = (Expr *)
+ transformAssignmentIndirection(pstate,
+ (Node *) param,
+ targetName,
+ targetIsArray,
+ typid,
+ typmod,
+ InvalidOid,
+ stmt->target,
+ indirection_head,
+ (Node *) expr,
+ COERCION_ASSIGNMENT,
+ stmt->location);
+ }
+ else
+ coerced_expr = (Expr *)
+ coerce_to_target_type(pstate,
+ (Node *) expr,
+ exprtypid,
+ typid, typmod,
+ COERCION_ASSIGNMENT,
+ COERCE_IMPLICIT_CAST,
+ stmt->location);
+
+ if (coerced_expr == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("variable \"%s.%s\" is of type %s, but expression is of type %s",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid),
+ format_type_be(exprtypid)),
+ errhint("You will need to rewrite or cast the expression."),
+ parser_errposition(pstate, exprLocation((Node *) expr))));
+
+ exprListCoer = lappend(exprListCoer, coerced_expr);
+ }
+
+ /* generate query's target list using the computed list of expressions */
+ query = makeNode(Query);
+ query->commandType = CMD_SELECT;
+
+ foreach(lc, exprListCoer)
+ {
+ Expr *expr = (Expr *) lfirst(lc);
+ TargetEntry *tle;
+
+ tle = makeTargetEntry(expr,
+ i + 1,
+ FigureColname((Node *) expr),
+ false);
+ query->targetList = lappend(query->targetList, tle);
+ }
+
+ /* done building the range table and jointree */
+ query->rtable = pstate->p_rtable;
+ query->jointree = makeFromExpr(pstate->p_joinlist, NULL);
+
+ query->hasTargetSRFs = pstate->p_hasTargetSRFs;
+ query->hasSubLinks = pstate->p_hasSubLinks;
+ query->hasSessionVariables = pstate->p_hasSessionVariables;
+
+ /* this is top-level query */
+ query->canSetTag = true;
+
+ /*
+ * Save target session variable ID. It is used later for
+ * acquiring an AccessShareLock on target variable, setting
+ * plan dependency and finally for creating VariableDestReceiver.
+ */
+ query->resultVariable = varid;
+
+ assign_query_collations(pstate, query);
+
+ /*
+ * The query is executed as utility command by nested executor call.
+ * Assigned queryId is required in this case.
+ */
+ if (IsQueryIdEnabled())
+ JumbleQuery(query);
+
+ stmt->query = (Node *) query;
+
+ /* represent the command as a utility Query */
+ result = makeNode(Query);
+ result->commandType = CMD_UTILITY;
+ result->utilityStmt = (Node *) stmt;
+
+ return result;
+}
+
/*
* transformSetOperationStmt -
* transforms a set-operations tree
@@ -2059,6 +2304,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
foreach(l, lockingClause)
{
@@ -2534,6 +2780,7 @@ transformReturnStmt(ParseState *pstate, ReturnStmt *stmt)
qry->hasWindowFuncs = pstate->p_hasWindowFuncs;
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasAggs = pstate->p_hasAggs;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2601,6 +2848,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
qry->hasTargetSRFs = pstate->p_hasTargetSRFs;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
@@ -2891,9 +3139,15 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
/*
* Transform the target reference. Typically we will get back a Param
* node, but there's no reason to be too picky about its type.
+ *
+ * Session variables should not be used as target of a PL/pgSQL assign
+ * statement. So we should use a dedicated expression kind and disallow
+ * session variables there. The dedicated context allows to eliminate
+ * undesirable warnings about the possibility of a target PL/pgSQL variable
+ * shadowing a session variable.
*/
target = transformExpr(pstate, (Node *) cref,
- EXPR_KIND_UPDATE_TARGET);
+ EXPR_KIND_ASSIGN_TARGET);
targettype = exprType(target);
targettypmod = exprTypmod(target);
targetcollation = exprCollation(target);
@@ -2935,6 +3189,10 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
*/
type_id = exprType((Node *) tle->expr);
+ /*
+ * For indirection processing and additional casts we can use expr_kind
+ * EXPR_KIND_UPDATE_TARGET.
+ */
pstate->p_expr_kind = EXPR_KIND_UPDATE_TARGET;
if (indirection)
@@ -3077,6 +3335,8 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
(LockingClause *) lfirst(l), false);
}
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
+
assign_query_collations(pstate, qry);
/* this must be done after collations, for reliable comparison of exprs */
@@ -3350,6 +3610,16 @@ transformCallStmt(ParseState *pstate, CallStmt *stmt)
true,
stmt->funccall->location);
+ /*
+ * The arguments of CALL statement are evaluated by a direct expression
+ * executor call. This path is unsupported yet, so block it. It will be
+ * enabled later.
+ */
+ if (pstate->p_hasSessionVariables)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("session variable cannot be used as an argument")));
+
assign_expr_collations(pstate, node);
fexpr = castNode(FuncExpr, node);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 71c71272958..99fac3411da 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -297,7 +297,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
DropTransformStmt
DropUserMappingStmt ExplainStmt FetchStmt
GrantStmt GrantRoleStmt ImportForeignSchemaStmt IndexStmt InsertStmt
- ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
+ LetStmt ListenStmt LoadStmt LockStmt MergeStmt NotifyStmt ExplainableStmt PreparableStmt
CreateFunctionStmt AlterFunctionStmt ReindexStmt RemoveAggrStmt
RemoveFuncStmt RemoveOperStmt RenameStmt ReturnStmt RevokeStmt RevokeRoleStmt
RuleActionStmt RuleActionStmtOrEmpty RuleStmt
@@ -742,7 +742,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
KEEP KEY KEYS
LABEL LANGUAGE LARGE_P LAST_P LATERAL_P
- LEADING LEAKPROOF LEAST LEFT LEVEL LIKE LIMIT LISTEN LOAD LOCAL
+ LEADING LEAKPROOF LEAST LEFT LET LEVEL LIKE LIMIT LISTEN LOAD LOCAL
LOCALTIME LOCALTIMESTAMP LOCATION LOCK_P LOCKED LOGGED
MAPPING MATCH MATCHED MATERIALIZED MAXVALUE MERGE MERGE_ACTION METHOD
@@ -1089,6 +1089,7 @@ stmt:
| ImportForeignSchemaStmt
| IndexStmt
| InsertStmt
+ | LetStmt
| ListenStmt
| RefreshMatViewStmt
| LoadStmt
@@ -12868,6 +12869,38 @@ opt_hold: /* EMPTY */ { $$ = 0; }
| WITHOUT HOLD { $$ = 0; }
;
+/*****************************************************************************
+ *
+ * QUERY:
+ * LET STATEMENT
+ *
+ *****************************************************************************/
+LetStmt: LET ColId opt_indirection '=' a_expr
+ {
+ LetStmt *n = makeNode(LetStmt);
+ SelectStmt *select;
+ ResTarget *res;
+
+ n->target = lcons(makeString($2),
+ check_indirection($3, yyscanner));
+
+ select = makeNode(SelectStmt);
+ res = makeNode(ResTarget);
+
+ /* create target list for implicit query */
+ res->name = NULL;
+ res->indirection = NIL;
+ res->val = (Node *) $5;
+ res->location = @5;
+
+ select->targetList = list_make1(res);
+ n->query = (Node *) select;
+
+ n->location = @2;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* QUERY:
@@ -17939,6 +17972,7 @@ unreserved_keyword:
| LARGE_P
| LAST_P
| LEAKPROOF
+ | LET
| LEVEL
| LISTEN
| LOAD
@@ -18553,6 +18587,7 @@ bare_label_keyword:
| LEAKPROOF
| LEAST
| LEFT
+ | LET
| LEVEL
| LIKE
| LISTEN
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 0ac8966e30f..de0a4a5653a 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -580,6 +580,11 @@ check_agglevels_and_constraints(ParseState *pstate, Node *expr)
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
+
/*
* There is intentionally no default: case here, so that the
* compiler will warn if we add a new ParseExprKind without
@@ -970,6 +975,10 @@ transformWindowFuncCall(ParseState *pstate, WindowFunc *wfunc,
case EXPR_KIND_CYCLE_MARK:
errkind = true;
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
+ errkind = true;
+ break;
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 1f8e2d54673..988d1c66f56 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -17,6 +17,7 @@
#include "catalog/pg_aggregate.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
@@ -33,11 +34,13 @@
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "parser/parse_type.h"
+#include "storage/lmgr.h"
#include "utils/builtins.h"
#include "utils/date.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/timestamp.h"
+#include "utils/typcache.h"
#include "utils/xml.h"
/* GUC parameters */
@@ -106,6 +109,9 @@ static Expr *make_distinct_op(ParseState *pstate, List *opname,
Node *ltree, Node *rtree, int location);
static Node *make_nulltest_from_distinct(ParseState *pstate,
A_Expr *distincta, Node *arg);
+static Node *makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location);
/*
@@ -499,6 +505,89 @@ transformIndirection(ParseState *pstate, A_Indirection *ind)
return result;
}
+/*
+ * Returns true if the given expression kind is valid for session variables.
+ * Session variables can be used everywhere where external parameters can be
+ * used. Session variables are not allowed in DDL commands or in constraints.
+ *
+ * An identifier can be parsed as a session variable only for expression kinds
+ * where session variables are allowed. This is the primary usage of this
+ * function.
+ *
+ * The second usage of this function is to decide whether a "column does not
+ * exist" or a "column or variable does not exist" error message should be
+ * printed. When we are in an expression where session variables cannot be
+ * used, we raise the first form of error message.
+ */
+static bool
+expr_kind_allows_session_variables(ParseExprKind p_expr_kind)
+{
+ bool result = false;
+
+ switch (p_expr_kind)
+ {
+ case EXPR_KIND_NONE:
+ Assert(false); /* can't happen */
+ return false;
+
+ /* session variables allowed */
+ case EXPR_KIND_OTHER:
+ case EXPR_KIND_JOIN_ON:
+ case EXPR_KIND_FROM_SUBSELECT:
+ case EXPR_KIND_FROM_FUNCTION:
+ case EXPR_KIND_WHERE:
+ case EXPR_KIND_HAVING:
+ case EXPR_KIND_FILTER:
+ case EXPR_KIND_WINDOW_PARTITION:
+ case EXPR_KIND_WINDOW_ORDER:
+ case EXPR_KIND_WINDOW_FRAME_RANGE:
+ case EXPR_KIND_WINDOW_FRAME_ROWS:
+ case EXPR_KIND_WINDOW_FRAME_GROUPS:
+ case EXPR_KIND_SELECT_TARGET:
+ case EXPR_KIND_INSERT_TARGET:
+ case EXPR_KIND_UPDATE_SOURCE:
+ case EXPR_KIND_UPDATE_TARGET:
+ case EXPR_KIND_MERGE_WHEN:
+ case EXPR_KIND_MERGE_RETURNING:
+ case EXPR_KIND_GROUP_BY:
+ case EXPR_KIND_ORDER_BY:
+ case EXPR_KIND_DISTINCT_ON:
+ case EXPR_KIND_LIMIT:
+ case EXPR_KIND_OFFSET:
+ case EXPR_KIND_RETURNING:
+ case EXPR_KIND_VALUES:
+ case EXPR_KIND_VALUES_SINGLE:
+ case EXPR_KIND_ALTER_COL_TRANSFORM:
+ case EXPR_KIND_EXECUTE_PARAMETER:
+ case EXPR_KIND_POLICY:
+ case EXPR_KIND_CALL_ARGUMENT:
+ case EXPR_KIND_COPY_WHERE:
+ case EXPR_KIND_LET_TARGET:
+ result = true;
+ break;
+
+ /* session variables not allowed */
+ case EXPR_KIND_CHECK_CONSTRAINT:
+ case EXPR_KIND_DOMAIN_CHECK:
+ case EXPR_KIND_COLUMN_DEFAULT:
+ case EXPR_KIND_FUNCTION_DEFAULT:
+ case EXPR_KIND_INDEX_EXPRESSION:
+ case EXPR_KIND_INDEX_PREDICATE:
+ case EXPR_KIND_STATS_EXPRESSION:
+ case EXPR_KIND_TRIGGER_WHEN:
+ case EXPR_KIND_PARTITION_BOUND:
+ case EXPR_KIND_PARTITION_EXPRESSION:
+ case EXPR_KIND_GENERATED_COLUMN:
+ case EXPR_KIND_JOIN_USING:
+ case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ result = false;
+ break;
+ }
+
+ return result;
+}
+
/*
* Transform a ColumnRef.
*
@@ -575,6 +664,8 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
case EXPR_KIND_COPY_WHERE:
case EXPR_KIND_GENERATED_COLUMN:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
@@ -847,8 +938,61 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
}
/*
- * Throw error if no translation found.
+ * There are contexts where session variables are not allowed. We don't
+ * need to identify session variables in such a context, but identifying
+ * them allows us to raise meaningful error messages like "you cannot use
+ * session variables here".
*/
+ if (expr_kind_allows_session_variables(pstate->p_expr_kind))
+ {
+ Oid varid = InvalidOid;
+ char *attrname = NULL;
+ bool not_unique;
+
+ /* -----
+ * Session variables are shadowed by columns, routine variables or
+ * routine arguments. We certainly don't want to use a session variable
+ * when it is exactly shadowed, but a RTE like this is conceivable:
+ *
+ * CREATE TYPE t AS (c int);
+ * CREATE VARIABLE foo AS t;
+ * CREATE TABLE foo(a int, b int);
+ *
+ * SELECT foo.a, foo.b, foo.c FROM foo;
+ *
+ * However, that is very confusing, so we disallow it. We don't try to
+ * identify a variable if we know that it would be shadowed.
+ * -----
+ */
+ if (!node && !(relname && crerr == CRERR_NO_COLUMN))
+ {
+ /* takes an AccessShareLock on the session variable */
+ varid = IdentifyVariable(cref->fields, &attrname, ¬_unique, false);
+
+ if (OidIsValid(varid))
+ {
+ Oid typid;
+ int32 typmod;
+ Oid collid;
+
+ if (not_unique)
+ ereport(ERROR,
+ (errcode(ERRCODE_AMBIGUOUS_PARAMETER),
+ errmsg("session variable reference \"%s\" is ambiguous",
+ NameListToString(cref->fields)),
+ parser_errposition(pstate, cref->location)));
+
+ get_session_variable_type_typmod_collid(varid, &typid, &typmod,
+ &collid);
+
+ node = makeParamSessionVariable(pstate,
+ varid, typid, typmod, collid,
+ attrname, cref->location);
+ }
+ }
+ }
+
+ /* throw an error if no translation was found */
if (node == NULL)
{
switch (crerr)
@@ -880,6 +1024,75 @@ transformColumnRef(ParseState *pstate, ColumnRef *cref)
return node;
}
+/*
+ * Generate param variable for reference to session variable
+ */
+static Node *
+makeParamSessionVariable(ParseState *pstate,
+ Oid varid, Oid typid, int32 typmod, Oid collid,
+ char *attrname, int location)
+{
+ Param *param;
+
+ param = makeNode(Param);
+
+ param->paramkind = PARAM_VARIABLE;
+ param->paramvarid = varid;
+ param->paramtype = typid;
+ param->paramtypmod = typmod;
+ param->paramcollid = collid;
+
+ pstate->p_hasSessionVariables = true;
+
+ if (attrname != NULL)
+ {
+ TupleDesc tupdesc;
+ int i;
+
+ tupdesc = lookup_rowtype_tupdesc_noerror(typid, typmod, true);
+ if (!tupdesc)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("variable \"%s.%s\" is of type \"%s\", which is not a composite type",
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid),
+ format_type_be(typid)),
+ parser_errposition(pstate, location)));
+
+ for (i = 0; i < tupdesc->natts; i++)
+ {
+ Form_pg_attribute att = TupleDescAttr(tupdesc, i);
+
+ if (strcmp(attrname, NameStr(att->attname)) == 0 &&
+ !att->attisdropped)
+ {
+ /* success, so generate a FieldSelect expression */
+ FieldSelect *fselect = makeNode(FieldSelect);
+
+ fselect->arg = (Expr *) param;
+ fselect->fieldnum = i + 1;
+ fselect->resulttype = att->atttypid;
+ fselect->resulttypmod = att->atttypmod;
+ /* save attribute's collation for parse_collate.c */
+ fselect->resultcollid = att->attcollation;
+
+ ReleaseTupleDesc(tupdesc);
+ return (Node *) fselect;
+ }
+ }
+
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_COLUMN),
+ errmsg("could not identify column \"%s\" in variable \"%s.%s\"",
+ attrname,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid)),
+ parser_errposition(pstate, location)));
+ }
+
+ return (Node *) param;
+}
+
static Node *
transformParamRef(ParseState *pstate, ParamRef *pref)
{
@@ -1815,6 +2028,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_VALUES:
case EXPR_KIND_VALUES_SINGLE:
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_LET_TARGET:
/* okay */
break;
case EXPR_KIND_CHECK_CONSTRAINT:
@@ -1858,6 +2072,9 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
case EXPR_KIND_GENERATED_COLUMN:
err = _("cannot use subquery in column generation expression");
break;
+ case EXPR_KIND_ASSIGN_TARGET:
+ err = _("cannot use subquery as target of assign statement");
+ break;
/*
* There is intentionally no default: case here, so that the
@@ -3215,6 +3432,10 @@ ParseExprKindName(ParseExprKind exprKind)
return "GENERATED AS";
case EXPR_KIND_CYCLE_MARK:
return "CYCLE";
+ case EXPR_KIND_ASSIGN_TARGET:
+ return "ASSIGN";
+ case EXPR_KIND_LET_TARGET:
+ return "LET";
/*
* There is intentionally no default: case here, so that the
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index 583bbbf232f..dc25f6dcd0e 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -2656,6 +2656,8 @@ check_srf_call_placement(ParseState *pstate, Node *last_srf, int location)
err = _("set-returning functions are not allowed in column generation expressions");
break;
case EXPR_KIND_CYCLE_MARK:
+ case EXPR_KIND_ASSIGN_TARGET:
+ case EXPR_KIND_LET_TARGET:
errkind = true;
break;
diff --git a/src/backend/parser/parse_merge.c b/src/backend/parser/parse_merge.c
index 51d7703eff7..244efcddf32 100644
--- a/src/backend/parser/parse_merge.c
+++ b/src/backend/parser/parse_merge.c
@@ -405,6 +405,7 @@ transformMergeStmt(ParseState *pstate, MergeStmt *stmt)
qry->hasTargetSRFs = false;
qry->hasSubLinks = pstate->p_hasSubLinks;
+ qry->hasSessionVariables = pstate->p_hasSessionVariables;
assign_query_collations(pstate, qry);
diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c
index b620766c938..b2f764b657f 100644
--- a/src/backend/tcop/dest.c
+++ b/src/backend/tcop/dest.c
@@ -38,6 +38,7 @@
#include "executor/functions.h"
#include "executor/tqueue.h"
#include "executor/tstoreReceiver.h"
+#include "executor/svariableReceiver.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
@@ -155,6 +156,9 @@ CreateDestReceiver(CommandDest dest)
case DestExplainSerialize:
return CreateExplainSerializeDestReceiver(NULL);
+
+ case DestVariable:
+ return CreateVariableDestReceiver(InvalidOid);
}
/* should never get here */
@@ -191,6 +195,7 @@ EndCommand(const QueryCompletion *qc, CommandDest dest, bool force_undecorated_o
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -237,6 +242,7 @@ NullCommand(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
@@ -281,6 +287,7 @@ ReadyForQuery(CommandDest dest)
case DestTransientRel:
case DestTupleQueue:
case DestExplainSerialize:
+ case DestVariable:
break;
}
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 99a51877d34..7a508a3644f 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -49,6 +49,7 @@
#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
+#include "commands/session_variable.h"
#include "commands/subscriptioncmds.h"
#include "commands/tablecmds.h"
#include "commands/tablespace.h"
@@ -235,6 +236,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CallStmt:
case T_DoStmt:
+ case T_LetStmt:
{
/*
* Commands inside the DO block or the called procedure might
@@ -1067,6 +1069,11 @@ standard_ProcessUtility(PlannedStmt *pstmt,
break;
}
+ case T_LetStmt:
+ ExecuteLetStmt(pstate, (LetStmt *) parsetree, params,
+ queryEnv, qc);
+ break;
+
default:
/* All other statement types have event trigger support */
ProcessUtilitySlow(pstate, pstmt, queryString,
@@ -2206,6 +2213,10 @@ UtilityContainsQuery(Node *parsetree)
return UtilityContainsQuery(qry->utilityStmt);
return qry;
+ case T_LetStmt:
+ qry = castNode(Query, ((LetStmt *) parsetree)->query);
+ return qry;
+
default:
return NULL;
}
@@ -2404,6 +2415,10 @@ CreateCommandTag(Node *parsetree)
tag = CMDTAG_SELECT;
break;
+ case T_LetStmt:
+ tag = CMDTAG_LET;
+ break;
+
/* utility statements --- same whether raw or cooked */
case T_TransactionStmt:
{
@@ -3289,6 +3304,7 @@ GetCommandLogLevel(Node *parsetree)
break;
case T_PLAssignStmt:
+ case T_LetStmt:
lev = LOGSTMT_ALL;
break;
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 467b08198b8..f23f511cd56 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -37,6 +37,7 @@
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablespace.h"
#include "common/keywords.h"
@@ -534,6 +535,7 @@ static char *generate_function_name(Oid funcid, int nargs,
static char *generate_operator_name(Oid operid, Oid arg1, Oid arg2);
static void add_cast_to(StringInfo buf, Oid typid);
static char *generate_qualified_type_name(Oid typid);
+static char *generate_session_variable_name(Oid varid);
static text *string_to_text(char *str);
static char *flatten_reloptions(Oid relid);
static void get_reloptions(StringInfo buf, Datum reloptions);
@@ -8729,6 +8731,14 @@ get_parameter(Param *param, deparse_context *context)
return;
}
+ /* translate paramvarid to session variable name */
+ if (param->paramkind == PARAM_VARIABLE)
+ {
+ appendStringInfo(context->buf, "%s",
+ generate_session_variable_name(param->paramvarid));
+ return;
+ }
+
/*
* Alternatively, maybe it's a subplan output, which we print as a
* reference to the subplan. (We could drill down into the subplan and
@@ -13556,6 +13566,42 @@ generate_collation_name(Oid collid)
return result;
}
+/*
+ * generate_session_variable_name
+ * Compute the name to display for a session variable specified by OID
+ *
+ * The result includes all necessary quoting and schema-prefixing.
+ */
+static char *
+generate_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+ char *nspname;
+ char *result;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = NameStr(varform->varname);
+
+ if (!VariableIsVisible(varid))
+ nspname = get_namespace_name_or_temp(varform->varnamespace);
+ else
+ nspname = NULL;
+
+ result = quote_qualified_identifier(nspname, varname);
+
+ ReleaseSysCache(tup);
+
+ return result;
+}
+
/*
* Given a C string, produce a TEXT datum.
*
diff --git a/src/backend/utils/cache/plancache.c b/src/backend/utils/cache/plancache.c
index 9bcbc4c3e97..7c93b9a49b4 100644
--- a/src/backend/utils/cache/plancache.c
+++ b/src/backend/utils/cache/plancache.c
@@ -58,6 +58,7 @@
#include "access/transam.h"
#include "catalog/namespace.h"
+#include "catalog/pg_variable.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
@@ -154,6 +155,7 @@ InitPlanCache(void)
CacheRegisterSyscacheCallback(AMOPOPID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNSERVEROID, PlanCacheSysCallback, (Datum) 0);
CacheRegisterSyscacheCallback(FOREIGNDATAWRAPPEROID, PlanCacheSysCallback, (Datum) 0);
+ CacheRegisterSyscacheCallback(VARIABLEOID, PlanCacheObjectCallback, (Datum) 0);
}
/*
@@ -2165,17 +2167,32 @@ ScanQueryForLocks(Query *parsetree, bool acquire)
/*
* Recurse into sublink subqueries, too. But we already did the ones in
- * the rtable and cteList.
+ * the rtable and cteList. We need to force a recursive call for session
+ * variables too, to find and lock variables used in the query (see
+ * ScanQueryWalker).
*/
- if (parsetree->hasSubLinks)
+ if (parsetree->hasSubLinks ||
+ parsetree->hasSessionVariables)
{
query_tree_walker(parsetree, ScanQueryWalker, &acquire,
QTW_IGNORE_RC_SUBQUERIES);
}
+
+ /* process session variables */
+ if (OidIsValid(parsetree->resultVariable))
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, parsetree->resultVariable,
+ 0, AccessShareLock);
+ }
}
/*
- * Walker to find sublink subqueries for ScanQueryForLocks
+ * Walker to find sublink subqueries or referenced session variables
+ * for ScanQueryForLocks
*/
static bool
ScanQueryWalker(Node *node, bool *acquire)
@@ -2190,6 +2207,20 @@ ScanQueryWalker(Node *node, bool *acquire)
ScanQueryForLocks(castNode(Query, sub->subselect), *acquire);
/* Fall through to process lefthand args of SubLink */
}
+ else if (IsA(node, Param))
+ {
+ Param *p = (Param *) node;
+
+ if (p->paramkind == PARAM_VARIABLE)
+ {
+ if (acquire)
+ LockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ else
+ UnlockDatabaseObject(VariableRelationId, p->paramvarid,
+ 0, AccessShareLock);
+ }
+ }
/*
* Do NOT recurse into Query nodes, because ScanQueryForLocks already
@@ -2320,7 +2351,9 @@ PlanCacheRelCallback(Datum arg, Oid relid)
/*
* PlanCacheObjectCallback
- * Syscache inval callback function for PROCOID and TYPEOID caches
+ * Syscache inval callback function for TYPEOID, PROCOID, NAMESPACEOID,
+ * OPEROID, AMOPOPID, FOREIGNSERVEROID, FOREIGNDATAWRAPPEROID and
+ * VARIABLEOID caches.
*
* Invalidate all plans mentioning the object with the specified hash value,
* or all plans mentioning any member of this cache if hashvalue == 0.
diff --git a/src/backend/utils/fmgr/fmgr.c b/src/backend/utils/fmgr/fmgr.c
index 782291d9998..093622fbdc4 100644
--- a/src/backend/utils/fmgr/fmgr.c
+++ b/src/backend/utils/fmgr/fmgr.c
@@ -2026,9 +2026,13 @@ get_call_expr_arg_stable(Node *expr, int argnum)
*/
if (IsA(arg, Const))
return true;
- if (IsA(arg, Param) &&
- ((Param *) arg)->paramkind == PARAM_EXTERN)
- return true;
+ if (IsA(arg, Param))
+ {
+ Param *p = (Param *) arg;
+
+ if (p->paramkind == PARAM_EXTERN || p->paramkind == PARAM_VARIABLE)
+ return true;
+ }
return false;
}
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 7fe19a568f1..39d1b6aa610 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -1228,8 +1228,8 @@ static const char *const sql_commands[] = {
"ABORT", "ALTER", "ANALYZE", "BEGIN", "CALL", "CHECKPOINT", "CLOSE", "CLUSTER",
"COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE",
"DELETE FROM", "DISCARD", "DO", "DROP", "END", "EXECUTE", "EXPLAIN",
- "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LISTEN", "LOAD", "LOCK",
- "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
+ "FETCH", "GRANT", "IMPORT FOREIGN SCHEMA", "INSERT INTO", "LET",
+ "LISTEN", "LOAD", "LOCK", "MERGE INTO", "MOVE", "NOTIFY", "PREPARE",
"REASSIGN", "REFRESH MATERIALIZED VIEW", "REINDEX", "RELEASE",
"RESET", "REVOKE", "ROLLBACK",
"SAVEPOINT", "SECURITY LABEL", "SELECT", "SET", "SHOW", "START",
@@ -4701,6 +4701,14 @@ match_previous_words(int pattern_id,
else if (TailMatches("VALUES") && !TailMatches("DEFAULT", "VALUES"))
COMPLETE_WITH("(");
+/* LET */
+ /* If prev. word is LET suggest a list of variables */
+ else if (Matches("LET"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ /* Complete LET <variable> with "=" */
+ else if (TailMatches("LET", MatchAny))
+ COMPLETE_WITH("=");
+
/* LOCK */
/* Complete LOCK [TABLE] [ONLY] with a list of tables */
else if (Matches("LOCK"))
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index bdac0c13bec..5060b8c9490 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -174,6 +174,7 @@ extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
extern List *NamesFromList(List *names);
extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+extern Oid IdentifyVariable(List *names, char **attrname, bool *not_unique, bool noerror);
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
index 3d3c6eb24b5..5b45be5afaf 100644
--- a/src/include/catalog/pg_variable.h
+++ b/src/include/catalog/pg_variable.h
@@ -18,6 +18,7 @@
#ifndef PG_VARIABLE_H
#define PG_VARIABLE_H
+#include "access/xlogdefs.h"
#include "catalog/genbki.h"
#include "catalog/objectaddress.h"
#include "catalog/pg_variable_d.h"
@@ -35,6 +36,14 @@ CATALOG(pg_variable,9222,VariableRelationId)
/* OID of entry in pg_type for variable's type */
Oid vartype BKI_LOOKUP(pg_type);
+ /*
+ * Used for identity check [oid, create_lsn].
+ *
+ * This column of the 8-byte XlogRecPtr type should be at an address that
+ * is divisible by 8, but before any column of type NameData.
+ */
+ XLogRecPtr varcreate_lsn;
+
/* variable name */
NameData varname;
diff --git a/src/include/commands/session_variable.h b/src/include/commands/session_variable.h
new file mode 100644
index 00000000000..2391b9ad443
--- /dev/null
+++ b/src/include/commands/session_variable.h
@@ -0,0 +1,30 @@
+/*-------------------------------------------------------------------------
+ *
+ * sessionvariable.h
+ * prototypes for sessionvariable.c.
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/commands/session_variable.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SESSIONVARIABLE_H
+#define SESSIONVARIABLE_H
+
+#include "nodes/params.h"
+#include "nodes/parsenodes.h"
+#include "parser/parse_node.h"
+#include "tcop/cmdtag.h"
+#include "utils/queryenvironment.h"
+
+extern void SetSessionVariable(Oid varid, Datum value, bool isNull);
+extern Datum GetSessionVariable(Oid varid, bool *isNull);
+
+extern void ExecuteLetStmt(ParseState *pstate, LetStmt *stmt, ParamListInfo params,
+ QueryEnvironment *queryEnv, QueryCompletion *qc);
+
+#endif
diff --git a/src/include/executor/svariableReceiver.h b/src/include/executor/svariableReceiver.h
new file mode 100644
index 00000000000..db44d8b94c6
--- /dev/null
+++ b/src/include/executor/svariableReceiver.h
@@ -0,0 +1,22 @@
+/*-------------------------------------------------------------------------
+ *
+ * svariableReceiver.h
+ * prototypes for svariableReceiver.c
+ *
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/executor/svariableReceiver.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef SVARIABLE_RECEIVER_H
+#define SVARIABLE_RECEIVER_H
+
+#include "tcop/dest.h"
+
+extern DestReceiver *CreateVariableDestReceiver(Oid varid);
+
+#endif /* SVARIABLE_RECEIVER_H */
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 5b6cadb5a6c..79c0732aad5 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -642,6 +642,16 @@ typedef struct AsyncRequest
* tuples) */
} AsyncRequest;
+/* ----------------
+ * SessionVariableValue
+ * ----------------
+ */
+typedef struct SessionVariableValue
+{
+ bool isnull;
+ Datum value;
+} SessionVariableValue;
+
/* ----------------
* EState information
*
@@ -702,6 +712,10 @@ typedef struct EState
ParamListInfo es_param_list_info; /* values of external params */
ParamExecData *es_param_exec_vals; /* values of internal params */
+ /* Session variables info: */
+ int es_num_session_variables; /* number of used variables */
+ SessionVariableValue *es_session_variables; /* array of copies of values */
+
QueryEnvironment *es_queryEnv; /* query environment */
/* Other working state: */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index ae4b6a3862c..8f874a08d29 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -142,6 +142,9 @@ typedef struct Query
*/
int resultRelation pg_node_attr(query_jumble_ignore);
+ /* target variable of LET statement */
+ Oid resultVariable;
+
/* has aggregates in tlist or havingQual */
bool hasAggs pg_node_attr(query_jumble_ignore);
/* has window functions in tlist */
@@ -162,6 +165,8 @@ typedef struct Query
bool hasRowSecurity pg_node_attr(query_jumble_ignore);
/* parser has added an RTE_GROUP RTE */
bool hasGroupRTE pg_node_attr(query_jumble_ignore);
+ /* uses session variables */
+ bool hasSessionVariables pg_node_attr(query_jumble_ignore);
/* is a RETURN statement */
bool isReturn pg_node_attr(query_jumble_ignore);
@@ -2149,6 +2154,18 @@ typedef struct MergeStmt
ParseLoc stmt_len; /* length in bytes; 0 means "rest of string" */
} MergeStmt;
+/* ----------------------
+ * Let Statement
+ * ----------------------
+ */
+typedef struct LetStmt
+{
+ NodeTag type;
+ List *target; /* target variable */
+ Node *query; /* source expression */
+ ParseLoc location;
+} LetStmt;
+
/* ----------------------
* Select Statement
*
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index 1dd2d1560cb..bec087cb915 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -182,6 +182,18 @@ typedef struct PlannerGlobal
/* partition descriptors */
PartitionDirectory partition_directory pg_node_attr(read_write_ignore);
+
+ /* list of used session variables */
+ List *sessionVariables;
+
+ /* Oid of session variable used like target of LET command */
+ Oid resultVariable;
+
+ /* oid of session variable used like base node for assignment indirection */
+ Oid basenodeSessionVarid;
+
+ /* true, if we do SELECT permission check on basenodeSessionVarid */
+ bool basenodeSessionVarSelectCheck;
} PlannerGlobal;
/* macro for fetching the Plan associated with a SubPlan node */
@@ -532,6 +544,8 @@ struct PlannerInfo
bool placeholdersFrozen;
/* true if planning a recursive WITH item */
bool hasRecursion;
+ /* true if session variables were used */
+ bool hasSessionVariables;
/*
* The rangetable index for the RTE_GROUP RTE, or 0 if there is no
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index 658d76225e4..492b9d97e5c 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -138,6 +138,15 @@ typedef struct PlannedStmt
/* non-null if this is utility stmt */
Node *utilityStmt;
+ List *sessionVariables; /* OIDs for PARAM_VARIABLE Params */
+
+ /*
+ * The oid of session variable execluded from permission check.
+ * This session variable is used as base node of assignment indirection
+ * (and it is used only there).
+ */
+ int exclSelectPermCheckVarid;
+
/* statement location in source string (copied from Query) */
/* start location, or -1 if unknown */
ParseLoc stmt_location;
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 7d3b4198f26..3cc2f019abb 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -378,6 +378,9 @@ typedef struct Const
* of the `paramid' field contain the SubLink's subLinkId, and
* the low-order 16 bits contain the column number. (This type
* of Param is also converted to PARAM_EXEC during planning.)
+ *
+ * PARAM_VARIABLE: The parameter is a reference to a session variable
+ * (paramvarid holds the variable's OID).
*/
typedef enum ParamKind
{
@@ -385,6 +388,7 @@ typedef enum ParamKind
PARAM_EXEC,
PARAM_SUBLINK,
PARAM_MULTIEXPR,
+ PARAM_VARIABLE,
} ParamKind;
typedef struct Param
@@ -397,6 +401,16 @@ typedef struct Param
int32 paramtypmod pg_node_attr(query_jumble_ignore);
/* OID of collation, or InvalidOid if none */
Oid paramcollid pg_node_attr(query_jumble_ignore);
+ /* OID of session variable if it is used */
+ Oid paramvarid pg_node_attr(query_jumble_ignore);
+
+ /*
+ * true if param is used as base node of assignment indirection
+ * (when target of LET statement is an array field or an record field).
+ * For this param we do not check SELECT access right, because this
+ * param is used just for execution of UPDATE operation.
+ */
+ bool parambasenode;
/* token location, or -1 if unknown */
ParseLoc location;
} Param;
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index 9d3debcab28..ba4305d61a7 100644
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -131,4 +131,6 @@ extern void record_plan_function_dependency(PlannerInfo *root, Oid funcid);
extern void record_plan_type_dependency(PlannerInfo *root, Oid typid);
extern bool extract_query_dependencies_walker(Node *node, PlannerInfo *context);
+extern void pull_up_has_session_variables(PlannerInfo *root);
+
#endif /* PLANMAIN_H */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index 0ea0265de7c..8c0affba13b 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -257,6 +257,7 @@ PG_KEYWORD("leading", LEADING, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("leakproof", LEAKPROOF, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("least", LEAST, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("left", LEFT, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("let", LET, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("level", LEVEL, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("like", LIKE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("limit", LIMIT, RESERVED_KEYWORD, AS_LABEL)
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 994284019fb..0b7b69a4159 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -82,6 +82,8 @@ typedef enum ParseExprKind
EXPR_KIND_COPY_WHERE, /* WHERE condition in COPY FROM */
EXPR_KIND_GENERATED_COLUMN, /* generation expression for a column */
EXPR_KIND_CYCLE_MARK, /* cycle mark value */
+ EXPR_KIND_ASSIGN_TARGET, /* PL/pgSQL assignment target */
+ EXPR_KIND_LET_TARGET, /* LET target */
} ParseExprKind;
@@ -244,6 +246,7 @@ struct ParseState
bool p_hasTargetSRFs;
bool p_hasSubLinks;
bool p_hasModifyingCTE;
+ bool p_hasSessionVariables;
Node *p_last_srf; /* most recent set-returning func/op found */
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index ea86954dded..22082c30008 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -186,6 +186,7 @@ PG_CMDTAG(CMDTAG_GRANT, "GRANT", true, false, false)
PG_CMDTAG(CMDTAG_GRANT_ROLE, "GRANT ROLE", false, false, false)
PG_CMDTAG(CMDTAG_IMPORT_FOREIGN_SCHEMA, "IMPORT FOREIGN SCHEMA", true, false, false)
PG_CMDTAG(CMDTAG_INSERT, "INSERT", false, false, true)
+PG_CMDTAG(CMDTAG_LET, "LET", false, false, false)
PG_CMDTAG(CMDTAG_LISTEN, "LISTEN", false, false, false)
PG_CMDTAG(CMDTAG_LOAD, "LOAD", false, false, false)
PG_CMDTAG(CMDTAG_LOCK_TABLE, "LOCK TABLE", false, false, false)
diff --git a/src/include/tcop/dest.h b/src/include/tcop/dest.h
index 00c092e3d7c..6ce3ea0e617 100644
--- a/src/include/tcop/dest.h
+++ b/src/include/tcop/dest.h
@@ -97,6 +97,7 @@ typedef enum
DestTransientRel, /* results sent to transient relation */
DestTupleQueue, /* results sent to tuple queue */
DestExplainSerialize, /* results are serialized and discarded */
+ DestVariable, /* results sent to session variable */
} CommandDest;
/* ----------------
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index bb99781c56e..1cff5efa6f7 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8264,7 +8264,8 @@ exec_is_simple_query(PLpgSQL_expr *expr)
query->sortClause ||
query->limitOffset ||
query->limitCount ||
- query->setOperations)
+ query->setOperations ||
+ query->hasSessionVariables)
return false;
/*
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
index c36660ce6d3..f22467186e3 100644
--- a/src/test/regress/expected/session_variables.out
+++ b/src/test/regress/expected/session_variables.out
@@ -431,3 +431,1235 @@ DROP VARIABLE public.var1;
DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+-- check access rights
+CREATE ROLE regress_noowner;
+CREATE VARIABLE var1 AS int;
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+-- should fail
+SET ROLE TO regress_noowner;
+SELECT var1;
+ERROR: permission denied for session variable var1
+SELECT sqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: SQL function "sqlfx" statement 1
+SELECT plpgsqlfx(20);
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "$1 + var1"
+PL/pgSQL function plpgsqlfx(integer) line 1 at RETURN
+-- should be ok
+SELECT sqlfx_sd(20);
+ sqlfx_sd
+----------
+ 30
+(1 row)
+
+SELECT plpgsqlfx_sd(20);
+ plpgsqlfx_sd
+--------------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+-- should be ok
+SET ROLE TO regress_noowner;
+SELECT var1;
+ var1
+------
+ 10
+(1 row)
+
+SELECT sqlfx(20);
+ sqlfx
+-------
+ 30
+(1 row)
+
+SELECT plpgsqlfx(20);
+ plpgsqlfx
+-----------
+ 30
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+DROP ROLE regress_noowner;
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- start a new session
+\c
+SELECT * FROM test_view;
+ result
+--------
+ 0
+ 0
+(2 rows)
+
+LET var1 = 3.14;
+SELECT * FROM test_view;
+ result
+--------
+ 4.14
+ 5.14
+(2 rows)
+
+-- should fail, dependency
+DROP VARIABLE var1;
+ERROR: cannot drop session variable var1 because other objects depend on it
+DETAIL: view test_view depends on session variable var1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+NOTICE: drop cascades to view test_view
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+LET var1 = 'str1';
+LET var2 = 'str2';
+SELECT sqlfx1(sqlfx2('Hello'));
+ sqlfx1
+-------------------
+ str1, str2, Hello
+(1 row)
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+ QUERY PLAN
+------------------------------------------------------
+ Result
+ Output: sqlfx1(sqlfx2('Hello'::character varying))
+(2 rows)
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+SET plan_cache_mode TO force_generic_plan;
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 3.14
+(1 row)
+
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 6.28
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 9.42
+(1 row)
+
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+ plpgsqlfx
+-----------
+ 12.56
+(1 row)
+
+SELECT plpgsqlfx2(10.0);
+ plpgsqlfx2
+------------
+
+(1 row)
+
+SELECT var2;
+ var2
+------
+ 10.0
+(1 row)
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+ERROR: function plpgsqlfx2() does not exist
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+-- should be ok
+SELECT plpgsqlfx3();
+NOTICE: 30
+ plpgsqlfx3
+------------
+
+(1 row)
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+SET plan_cache_mode TO DEFAULT;
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 1
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 10
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: 55
+DROP VARIABLE var1;
+DROP TABLE testvar;
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+NOTICE: result array: {1,2,3,4,5,6,7,8,9,10}
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+-- should not crash (but is not supported yet)
+CALL p(v);
+ERROR: session variable cannot be used as an argument
+DO $$ BEGIN CALL p(v); END $$;
+ERROR: session variable cannot be used as an argument
+CONTEXT: SQL statement "CALL p(v)"
+PL/pgSQL function inline_code_block line 1 at CALL
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+-- should fail
+EXECUTE ptest(v);
+ERROR: session variable cannot be used as an argument
+DEALLOCATE ptest;
+DROP VARIABLE v;
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+-- should fail
+LET var1 = pi();
+ERROR: session variable "var1" doesn't exist
+LINE 1: LET var1 = pi();
+ ^
+SELECT var1;
+ERROR: column "var1" does not exist
+LINE 1: SELECT var1;
+ ^
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+ var1
+------------------
+ 3.14159265358979
+(1 row)
+
+SET search_path TO svartest;
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+ var1
+------------------
+ 13.1415926535898
+(1 row)
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to session variable svartest.var1
+CREATE VARIABLE var1 AS text;
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+SELECT var1;
+ var1
+-------
+ hello
+(1 row)
+
+DROP VARIABLE var1;
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+-- should fail
+SELECT var1;
+ERROR: domain int_domain does not allow null values
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+ var1
+------
+ 1000
+(1 row)
+
+-- should fail
+LET var1 = 10;
+ERROR: value for domain int_domain violates check constraint "int_domain_check"
+-- should fail
+LET var1 = NULL;
+ERROR: domain int_domain does not allow null values
+-- note - domain defaults are not supported yet (like PLpgSQL)
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+ var1
+----------------------------------------
+ {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+(1 row)
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+NOTICE: {"{[2,8),[11,14)}","{[5,8),[12,100)}"}
+DROP VARIABLE var1;
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+ var1
+------
+ 100
+(1 row)
+
+SET search_path to public, svartest;
+SELECT var1;
+ var1
+------
+ 100
+(1 row)
+
+DROP SCHEMA svartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table foo
+drop cascades to session variable var1
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+LET var2[var1] = 0;
+SELECT var2;
+ var2
+-----------
+ [2:2]={0}
+(1 row)
+
+DROP VARIABLE var1, var2;
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+LET var1 = 2;
+LET var2 = '{}'::int[];
+SELECT var2;
+ var2
+------
+ {}
+(1 row)
+
+DROP VARIABLE var1, var2;
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+ERROR: syntax error at or near "LET"
+LINE 1: WITH x AS (LET var1 = 100) SELECT * FROM x;
+ ^
+-- should be ok
+LET var1 = generate_series(1, 1);
+-- should fail
+LET var1 = generate_series(1, 2);
+ERROR: expression returned more than one row
+LET var1 = generate_series(1, 0);
+ERROR: expression returned no rows
+DROP VARIABLE var1;
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+SELECT v1;
+ v1
+------------
+ (1,2,3.00)
+(1 row)
+
+SELECT v2;
+ v2
+---------------
+ (10,20,31.40)
+(1 row)
+
+SELECT (v1).*;
+ x | y | z
+---+---+------
+ 1 | 2 | 3.00
+(1 row)
+
+SELECT (v2).*;
+ x | y | z
+----+----+-------
+ 10 | 20 | 31.40
+(1 row)
+
+SELECT v1.x + v1.z;
+ ?column?
+----------
+ 4.00
+(1 row)
+
+SELECT v2.x + v2.z;
+ ?column?
+----------
+ 41.40
+(1 row)
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail
+SELECT v2.x;
+ERROR: permission denied for session variable v2
+SET ROLE TO DEFAULT;
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+ERROR: improper qualified name (too many dotted names): nodb.noschema.novar.nofield.nosubfield
+LET nodb.noschema.novar.nofield = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar.nofield
+LET nodb.noschema.novar = 10;
+ERROR: cross-database references are not implemented: nodb.noschema.novar
+CREATE TYPE t1 AS (a int, b numeric, c text);
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+ v1
+----------------------------
+ (1,3.14159265358979,hello)
+(1 row)
+
+LET v1.b = 10.2222;
+SELECT v1;
+ v1
+-------------------
+ (1,10.2222,hello)
+(1 row)
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+ERROR: cannot assign to field "x" of column "v1" because there is no such column in data type t1
+LINE 1: LET v1.x = 10;
+ ^
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+ERROR: assignment expression returned 3 columns
+LINE 1: LET v1 = (NULL::t1).*;
+ ^
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+ v1
+-------------
+ (1,10.2222)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+ v1
+--------------
+ (1,10.2222,)
+(1 row)
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+ v1
+--------------
+ (10,10.3,20)
+(1 row)
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+ v1
+---------
+ (10,20)
+(1 row)
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+ERROR: cannot alter type "t1" because session variable "public.v1" uses it
+DROP VARIABLE v1;
+DROP TYPE t1;
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+ var1
+----------------------------------
+ (10,3.14159265358979,05-26-2023)
+(1 row)
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+ERROR: cannot alter table "svar_test" because session variable "public.var1" uses it
+-- should fail
+DROP TABLE svar_test;
+ERROR: cannot drop table svar_test because other objects depend on it
+DETAIL: session variable var1 depends on type svar_test
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+CREATE ROLE regress_var_test_role;
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+-- should fail
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should be ok
+SELECT var1.a;
+ a
+------
+ 1000
+(1 row)
+
+SELECT var1;
+ var1
+------------
+ (1000,100)
+(1 row)
+
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+NOTICE: (0,100)
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+NOTICE: 0
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+-- should fail again
+SELECT var1.a;
+ERROR: permission denied for session variable var1
+SELECT var1;
+ERROR: permission denied for session variable var1
+LET var1.a = var1.a + 10;
+ERROR: permission denied for session variable var1
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+ERROR: permission denied for session variable var1
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: PL/pgSQL expression "var1.a"
+PL/pgSQL function inline_code_block line 1 at RAISE
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+ERROR: permission denied for session variable var1
+CONTEXT: SQL statement "LET var1.a = var1.a + 10"
+PL/pgSQL function inline_code_block line 1 at SQL statement
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+-- should fail
+SELECT var1.a;
+ERROR: variable "public.var1" is of type "text", which is not a composite type
+LINE 1: SELECT var1.a;
+ ^
+SELECT var2.c;
+ERROR: could not identify column "c" in variable "public.var2"
+LINE 1: SELECT var2.c;
+ ^
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+CREATE VARIABLE var1 AS int;
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+-- should fail
+LET var1 = '1'::jsonb;
+ERROR: variable "public.var1" is of type integer, but expression is of type jsonb
+LINE 1: LET var1 = '1'::jsonb;
+ ^
+HINT: You will need to rewrite or cast the expression.
+-- should be ok
+LET var1 = '1'::jsonb::int;
+-- should fail
+LET var1.x = 10;
+ERROR: cannot assign to field "x" of session variable "public.var1" because its type integer is not a composite type
+LINE 1: LET var1.x = 10;
+ ^
+DROP VARIABLE var1;
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+-- should fail
+LET vartest.vartest = 1;
+ERROR: target "vartest.vartest" of LET command is ambiguous
+LINE 1: LET vartest.vartest = 1;
+ ^
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+ERROR: type "vartesttype" does not exist
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+ var1
+------------
+ {10.1,2.1}
+(1 row)
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+ERROR: set-returning functions are not allowed in LET
+LINE 1: LET var1[generate_series(1,3)] = 100;
+ ^
+DROP VARIABLE var1;
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+ var1
+--------------------
+ (10.2,"{0.0,0.0}")
+(1 row)
+
+LET var1.b[1] = 10.3;
+SELECT var1;
+ var1
+---------------------
+ (10.2,"{10.3,0.0}")
+(1 row)
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ count
+-------
+ 100
+(1 row)
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+ QUERY PLAN
+-----------------------------------
+ Aggregate
+ -> Seq Scan on svar_test
+ Filter: ((a % 10) = zero)
+(3 rows)
+
+LET zero = (SELECT count(*) FROM svar_test);
+-- result should be 1000
+SELECT zero;
+ zero
+------
+ 1000
+(1 row)
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO on;
+SELECT * FROM var1view;
+ result
+--------
+ 10
+(1 row)
+
+SET debug_parallel_query TO off;
+DROP VIEW var1view;
+DROP VARIABLE var1;
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 100
+(1 row)
+
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+-----
+ 1 | 200
+(1 row)
+
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+ id | v
+----+---
+(0 rows)
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+ relname
+----------
+ pg_class
+(1 row)
+
+DROP VARIABLE var1;
+CREATE TABLE xxtab(avar int);
+INSERT INTO xxtab VALUES(333);
+CREATE TYPE xxtype AS (avar int);
+CREATE VARIABLE xxtab AS xxtype;
+INSERT INTO xxtab VALUES(10);
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+CREATE VARIABLE public.avar AS int;
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+ avar
+------
+
+
+(2 rows)
+
+DROP VARIABLE xxtab;
+SELECT xxtab.avar FROM xxtab;
+ avar
+------
+ 333
+ 10
+(2 rows)
+
+DROP VARIABLE public.avar;
+DROP TYPE xxtype;
+DROP TABLE xxtab;
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+CREATE TABLE public.svar(a int, b int);
+INSERT INTO public.svar VALUES(10, 20);
+LET public.svar = (100, 200, 300);
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+SELECT svar.a FROM public.svar;
+ a
+----
+ 10
+(1 row)
+
+SELECT svar.* FROM public.svar;
+ a | b
+----+----
+ 10 | 20
+(1 row)
+
+-- show variable
+SELECT public.svar;
+ svar
+---------------
+ (100,200,300)
+(1 row)
+
+SELECT public.svar.c;
+ c
+-----
+ 300
+(1 row)
+
+SELECT (public.svar).*;
+ a | b | c
+-----+-----+-----
+ 100 | 200 | 300
+(1 row)
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+ERROR: column svar.c does not exist
+LINE 1: SELECT public.svar.c FROM public.svar;
+ ^
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+ c
+-----
+ 300
+(1 row)
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT var1.* FROM vartest_foo;
+ ^
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+ a | b
+----+----
+ 10 | 20
+ 30 | 40
+(2 rows)
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+ERROR: missing FROM-clause entry for table "var1"
+LINE 1: SELECT count(var1.*) FROM vartest_foo;
+ ^
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+ count
+-------
+ 2
+(1 row)
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+NOTICE: drop cascades to 2 other objects
+DETAIL: drop cascades to table vartest.vartest_foo
+drop cascades to session variable vartest.var1
+CREATE TYPE ab AS (a integer, b integer);
+CREATE VARIABLE v_ab AS ab;
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+CREATE SCHEMA v_ab;
+CREATE VARIABLE v_ab.a AS integer;
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+ a
+----
+ 10
+(1 row)
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+SET search_path TO public;
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+-- should be ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+-- should be still ok
+SELECT xxx_am;
+ xxx_am
+--------
+ (10)
+(1 row)
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+ERROR: session variable reference "xxx_am.b" is ambiguous
+LINE 1: SELECT xxx_am.b;
+ ^
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+ b
+----
+ 10
+(1 row)
+
+SELECT :"DBNAME".xxx_am.b;
+ b
+----
+ 20
+(1 row)
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+ b
+----
+ 10
+(1 row)
+
+SELECT x.b FROM xxx_am x;
+ b
+----
+ 10
+(1 row)
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+CREATE SCHEMA :"DBNAME";
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+SET search_path TO :"DBNAME";
+-- should be ambiguous
+SELECT :"DBNAME".b;
+ERROR: session variable reference "regression.b" is ambiguous
+LINE 1: SELECT "regression".b;
+ ^
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+ERROR: session variable reference "regression.regression.b" is ambiguous
+LINE 1: SELECT "regression"."regression".b;
+ ^
+CREATE TABLE :"DBNAME"(b int);
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+ b
+---
+(0 rows)
+
+DROP TABLE :"DBNAME";
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+RESET search_path;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
index eeb0f94ca3c..e72360d5254 100644
--- a/src/test/regress/sql/session_variables.sql
+++ b/src/test/regress/sql/session_variables.sql
@@ -295,3 +295,886 @@ DROP ROLE regress_variable_r1;
DROP ROLE regress_variable_r2;
DROP ROLE regress_variable_owner;
+
+-- check access rights
+CREATE ROLE regress_noowner;
+
+CREATE VARIABLE var1 AS int;
+
+CREATE OR REPLACE FUNCTION sqlfx(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx_sd(int)
+RETURNS int AS $$ SELECT $1 + var1 $$ LANGUAGE sql SECURITY DEFINER;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx_sd(int)
+RETURNS int AS $$ BEGIN RETURN $1 + var1; END $$ LANGUAGE plpgsql SECURITY DEFINER;
+
+LET var1 = 10;
+-- should be ok
+SELECT var1;
+SELECT sqlfx(20);
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx(20);
+SELECT plpgsqlfx_sd(20);
+
+-- should fail
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+-- should be ok
+SELECT sqlfx_sd(20);
+SELECT plpgsqlfx_sd(20);
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_noowner;
+
+-- should be ok
+SET ROLE TO regress_noowner;
+
+SELECT var1;
+SELECT sqlfx(20);
+SELECT plpgsqlfx(20);
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+DROP FUNCTION sqlfx(int);
+DROP FUNCTION plpgsqlfx(int);
+DROP FUNCTION sqlfx_sd(int);
+DROP FUNCTION plpgsqlfx_sd(int);
+
+DROP ROLE regress_noowner;
+
+-- use variables inside views
+CREATE VARIABLE var1 AS numeric;
+
+-- use variables in views
+CREATE VIEW test_view AS SELECT COALESCE(var1 + v, 0) AS result FROM generate_series(1,2) g(v);
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- start a new session
+\c
+
+SELECT * FROM test_view;
+LET var1 = 3.14;
+SELECT * FROM test_view;
+
+-- should fail, dependency
+DROP VARIABLE var1;
+
+-- should be ok
+DROP VARIABLE var1 CASCADE;
+
+CREATE VARIABLE var1 text;
+CREATE VARIABLE var2 text;
+
+-- use variables in SQL functions
+CREATE OR REPLACE FUNCTION sqlfx1(varchar)
+RETURNS varchar AS $$ SELECT var1 || ', ' || $1 $$ LANGUAGE sql;
+
+CREATE OR REPLACE FUNCTION sqlfx2( varchar)
+RETURNS varchar AS $$ SELECT var2 || ', ' || $1 $$ LANGUAGE sql;
+
+LET var1 = 'str1';
+LET var2 = 'str2';
+
+SELECT sqlfx1(sqlfx2('Hello'));
+
+-- inlining is blocked
+EXPLAIN (COSTS OFF, VERBOSE) SELECT sqlfx1(sqlfx2('Hello'));
+
+DROP FUNCTION sqlfx1(varchar);
+DROP FUNCTION sqlfx2(varchar);
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- access from cached plans should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx()
+RETURNS numeric AS $$ BEGIN RETURN var1; END $$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION plpgsqlfx2(numeric)
+RETURNS void AS $$ BEGIN LET var2 = $1; END $$ LANGUAGE plpgsql;
+
+SET plan_cache_mode TO force_generic_plan;
+
+LET var1 = 3.14;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 2;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- dependency (plan invalidation) should work
+CREATE VARIABLE var1 AS numeric;
+CREATE VARIABLE var2 AS numeric;
+
+LET var1 = 3.14 * 3;
+SELECT plpgsqlfx();
+LET var1 = 3.14 * 4;
+SELECT plpgsqlfx();
+
+SELECT plpgsqlfx2(10.0);
+SELECT var2;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP FUNCTION plpgsqlfx();
+DROP FUNCTION plpgsqlfx2();
+
+-- dependency on column type
+CREATE VARIABLE var1 AS int;
+CREATE TABLE testvar(a int, b int, c int);
+INSERT INTO testvar VALUES(10,20,30);
+
+ALTER TABLE testvar DROP COLUMN a;
+ALTER TABLE testvar DROP COLUMN b;
+
+CREATE FUNCTION plpgsqlfx3()
+RETURNS void AS $$
+BEGIN
+ LET var1 = (SELECT * FROM testvar);
+ RAISE NOTICE '%', var1;
+END
+$$ LANGUAGE plpgsql;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+ALTER TABLE testvar ALTER COLUMN c TYPE numeric;
+
+-- should be ok
+SELECT plpgsqlfx3();
+
+DROP FUNCTION plpgsqlfx3();
+DROP TABLE testvar;
+DROP VARIABLE var1;
+
+SET plan_cache_mode TO DEFAULT;
+
+-- repeated execution should not crash
+CREATE VARIABLE var1 int;
+CREATE TABLE testvar(a int);
+INSERT INTO testvar VALUES(1);
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a + var1 FROM testvar);
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = (SELECT a FROM testvar) + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DO $$
+BEGIN
+ LET var1 = 0;
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i + var1;
+ END LOOP;
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP TABLE testvar;
+
+-- usage LET statement in plpgsql should work
+CREATE VARIABLE var1 int;
+CREATE VARIABLE var2 numeric[];
+
+DO $$
+BEGIN
+ LET var2 = '{}'::int[];
+ FOR i IN 1..10
+ LOOP
+ LET var1 = i;
+ LET var2[var1] = i;
+ END LOOP;
+ RAISE NOTICE 'result array: %', var2;
+END;
+$$;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+
+-- CALL statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+
+CREATE PROCEDURE p(arg int) AS $$ BEGIN RAISE NOTICE '%', arg; END $$ LANGUAGE plpgsql;
+
+-- should not crash (but is not supported yet)
+CALL p(v);
+
+DO $$ BEGIN CALL p(v); END $$;
+
+DROP PROCEDURE p(int);
+DROP VARIABLE v;
+
+-- EXECUTE statement is not supported yet
+-- requires direct access to session variable from expression executor
+CREATE VARIABLE v int;
+LET v = 20;
+PREPARE ptest(int) AS SELECT $1;
+
+-- should fail
+EXECUTE ptest(v);
+
+DEALLOCATE ptest;
+DROP VARIABLE v;
+
+-- test search path
+CREATE SCHEMA svartest;
+CREATE VARIABLE svartest.var1 AS numeric;
+
+-- should fail
+LET var1 = pi();
+SELECT var1;
+
+-- should be ok
+LET svartest.var1 = pi();
+SELECT svartest.var1;
+
+SET search_path TO svartest;
+
+-- should be ok
+LET var1 = pi() + 10;
+SELECT var1;
+
+RESET search_path;
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS text;
+
+-- variables can be updated under RO transaction
+BEGIN;
+SET TRANSACTION READ ONLY;
+LET var1 = 'hello';
+COMMIT;
+
+SELECT var1;
+
+DROP VARIABLE var1;
+
+-- test of domains
+CREATE DOMAIN int_domain AS int NOT NULL CHECK (VALUE > 100);
+CREATE VARIABLE var1 AS int_domain;
+
+-- should fail
+SELECT var1;
+
+-- should be ok
+LET var1 = 1000;
+SELECT var1;
+
+-- should fail
+LET var1 = 10;
+
+-- should fail
+LET var1 = NULL;
+
+-- note - domain defaults are not supported yet (like PLpgSQL)
+
+DROP VARIABLE var1;
+DROP DOMAIN int_domain;
+
+-- the expression should remain "unknown"
+CREATE VARIABLE var1 AS int4multirange[];
+-- should be ok
+LET var1 = NULL;
+LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+LET var1[2] = '{[5,8),[12,100)}';
+SELECT var1;
+
+--It should work in plpgsql too
+DO $$
+BEGIN
+ LET var1 = NULL;
+ LET var1 = '{"{[2,8),[11,14)}","{[5,8),[12,14)}"}';
+ LET var1[2] = '{[5,8),[12,100)}';
+
+ RAISE NOTICE '%', var1;
+END;
+$$;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA svartest CREATE VARIABLE var1 AS int CREATE TABLE foo(a int);
+LET svartest.var1 = 100;
+SELECT svartest.var1;
+
+SET search_path to public, svartest;
+
+SELECT var1;
+
+DROP SCHEMA svartest CASCADE;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+LET var2[var1] = 0;
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+CREATE VARIABLE var1 AS int;
+CREATE VARIABLE var2 AS int[];
+
+LET var1 = 2;
+LET var2 = '{}'::int[];
+
+SELECT var2;
+
+DROP VARIABLE var1, var2;
+
+-- the LET statement should be disallowed in CTE
+CREATE VARIABLE var1 AS int;
+WITH x AS (LET var1 = 100) SELECT * FROM x;
+
+-- should be ok
+LET var1 = generate_series(1, 1);
+
+-- should fail
+LET var1 = generate_series(1, 2);
+LET var1 = generate_series(1, 0);
+
+DROP VARIABLE var1;
+
+-- composite variables
+CREATE TYPE sv_xyz AS (x int, y int, z numeric(10,2));
+
+CREATE VARIABLE v1 AS sv_xyz;
+CREATE VARIABLE v2 AS sv_xyz;
+
+LET v1 = (1, 2, 3.14);
+LET v2 = (10, 20, 3.14 * 10);
+
+-- should work too - there are prepared casts
+LET v1 = (1, 2, 3);
+
+SELECT v1;
+SELECT v2;
+SELECT (v1).*;
+SELECT (v2).*;
+
+SELECT v1.x + v1.z;
+SELECT v2.x + v2.z;
+
+-- access to composite fields should be safe too
+CREATE ROLE regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should fail
+SELECT v2.x;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE v1;
+DROP VARIABLE v2;
+DROP TYPE sv_xyz;
+DROP ROLE regress_var_test_role;
+
+-- should fail, wrong identifier
+LET nodb.noschema.novar.nofield.nosubfield = 10;
+LET nodb.noschema.novar.nofield = 10;
+LET nodb.noschema.novar = 10;
+
+CREATE TYPE t1 AS (a int, b numeric, c text);
+
+CREATE VARIABLE v1 AS t1;
+LET v1 = (1, pi(), 'hello');
+SELECT v1;
+LET v1.b = 10.2222;
+SELECT v1;
+
+-- should fail, attribute doesn't exist
+LET v1.x = 10;
+
+-- should fail, don't allow multi column query
+LET v1 = (NULL::t1).*;
+
+-- allow DROP or ADD ATTRIBUTE on composite types
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE c;
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+SELECT v1;
+
+LET v1 = (10, 10.3, 20);
+SELECT v1;
+
+-- should be ok
+ALTER TYPE t1 DROP ATTRIBUTE b;
+SELECT v1;
+
+-- should fail, disallow data type change
+ALTER TYPE t1 ALTER ATTRIBUTE c TYPE int;
+
+DROP VARIABLE v1;
+DROP TYPE t1;
+
+-- the table type can be used as composite type too
+CREATE TABLE svar_test(a int, b numeric, c date);
+CREATE VARIABLE var1 AS svar_test;
+
+LET var1 = (10, pi(), '2023-05-26');
+SELECT var1;
+
+-- should fail due dependency
+ALTER TABLE svar_test ALTER COLUMN a TYPE text;
+
+-- should fail
+DROP TABLE svar_test;
+
+DROP VARIABLE var1;
+DROP TABLE svar_test;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+CREATE VARIABLE var1 AS vartest_t1;
+CREATE TABLE vartesttab (xcol int);
+
+CREATE ROLE regress_var_test_role;
+
+GRANT UPDATE ON VARIABLE var1 TO regress_var_test_role;
+GRANT SELECT ON TABLE vartesttab TO regress_var_test_role;
+
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+LET var1 = (10, 20);
+LET var1.a = 30;
+
+DO $$
+BEGIN
+ LET var1 = (100, 100);
+ LET var1.a = 1000;
+END;
+$$;
+
+-- should fail
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+GRANT SELECT ON VARIABLE var1 TO regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should be ok
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+REVOKE SELECT ON VARIABLE var1 FROM regress_var_test_role;
+SET ROLE TO regress_var_test_role;
+
+-- should fail again
+SELECT var1.a;
+SELECT var1;
+LET var1.a = var1.a + 10;
+LET var1.a = (SELECT * FROM (SELECT count(*) FROM vartesttab WHERE xcol = var1.a + 10));
+
+DO $$ BEGIN RAISE NOTICE '%', var1; END $$;
+DO $$ BEGIN RAISE NOTICE '%', var1.a; END $$;
+DO $$ BEGIN LET var1.a = var1.a + 10; END $$;
+
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+DROP TABLE vartesttab;
+DROP ROLE regress_var_test_role;
+DROP TYPE vartest_t1;
+
+CREATE TYPE vartest_t1 AS (a int, b int);
+
+CREATE VARIABLE var1 AS text;
+CREATE VARIABLE var2 AS vartest_t1;
+
+-- should fail
+SELECT var1.a;
+SELECT var2.c;
+
+DROP VARIABLE var1;
+DROP VARIABLE var2;
+DROP TYPE vartest_t1;
+
+CREATE VARIABLE var1 AS int;
+
+LET var1 = 1;
+LET var1 = '1';
+LET var1 = 10.1;
+
+-- should fail
+LET var1 = '1'::jsonb;
+
+-- should be ok
+LET var1 = '1'::jsonb::int;
+
+-- should fail
+LET var1.x = 10;
+
+DROP VARIABLE var1;
+
+CREATE SCHEMA vartest;
+CREATE TYPE vartesttype AS (vartest int);
+CREATE VARIABLE vartest.vartest AS vartesttype;
+SET SEARCH_PATH TO vartest;
+
+-- should fail
+LET vartest.vartest = 1;
+
+DROP VARIABLE vartest.vartest;
+DROP TYPE vartesttype;
+DROP SCHEMA vartest;
+SET SEARCH_PATH TO DEFAULT;
+
+-- arrays are supported
+CREATE VARIABLE var1 AS numeric[];
+LET var1 = ARRAY[1.1,2.1];
+LET var1[1] = 10.1;
+SELECT var1;
+
+-- LET target doesn't allow srf, should fail
+LET var1[generate_series(1,3)] = 100;
+
+DROP VARIABLE var1;
+
+-- arrays inside composite
+CREATE TYPE t1 AS (a numeric, b numeric[]);
+CREATE VARIABLE var1 AS t1;
+LET var1 = (10.1, ARRAY[0.0, 0.0]);
+LET var1.a = 10.2;
+SELECT var1;
+LET var1.b[1] = 10.3;
+SELECT var1;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+-- Encourage use of parallel plans
+SET parallel_setup_cost = 0;
+SET parallel_tuple_cost = 0;
+SET min_parallel_table_scan_size = 0;
+SET max_parallel_workers_per_gather = 2;
+
+-- test on query with workers
+CREATE TABLE svar_test(a int);
+INSERT INTO svar_test SELECT * FROM generate_series(1,1000);
+ANALYZE svar_test;
+CREATE VARIABLE zero int;
+LET zero = 0;
+
+-- result should be 100
+SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+-- parallel execution is not supported yet
+EXPLAIN (COSTS OFF) SELECT count(*) FROM svar_test WHERE a%10 = zero;
+
+LET zero = (SELECT count(*) FROM svar_test);
+
+-- result should be 1000
+SELECT zero;
+
+DROP VARIABLE zero;
+DROP TABLE svar_test;
+
+RESET parallel_setup_cost;
+RESET parallel_tuple_cost;
+RESET min_parallel_table_scan_size;
+RESET max_parallel_workers_per_gather;
+
+-- the result of view should be same in parallel mode too
+CREATE VARIABLE var1 AS int;
+LET var1 = 10;
+
+CREATE VIEW var1view AS SELECT COALESCE(var1, 0) AS result;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO on;
+
+SELECT * FROM var1view;
+
+SET debug_parallel_query TO off;
+
+DROP VIEW var1view;
+DROP VARIABLE var1;
+
+CREATE VARIABLE varid int;
+CREATE TABLE svar_test(id int, v int);
+
+LET varid = 1;
+INSERT INTO svar_test VALUES(varid, 100);
+SELECT * FROM svar_test;
+UPDATE svar_test SET v = 200 WHERE id = varid;
+SELECT * FROM svar_test;
+DELETE FROM svar_test WHERE id = varid;
+SELECT * FROM svar_test;
+
+DROP TABLE svar_test;
+DROP VARIABLE varid;
+
+-- visibility check
+-- variables should be shadowed always
+CREATE VARIABLE var1 AS text;
+SELECT var1.relname FROM pg_class var1 WHERE var1.relname = 'pg_class';
+
+DROP VARIABLE var1;
+
+CREATE TABLE xxtab(avar int);
+
+INSERT INTO xxtab VALUES(333);
+
+CREATE TYPE xxtype AS (avar int);
+
+CREATE VARIABLE xxtab AS xxtype;
+
+INSERT INTO xxtab VALUES(10);
+
+-- it is ambiguous, but columns are preferred
+SELECT xxtab.avar FROM xxtab;
+
+-- should be ok
+SELECT avar FROM xxtab;
+
+CREATE VARIABLE public.avar AS int;
+
+-- should be ok, see the table
+SELECT avar FROM xxtab;
+
+-- should be ok
+SELECT public.avar FROM xxtab;
+
+DROP VARIABLE xxtab;
+
+SELECT xxtab.avar FROM xxtab;
+
+DROP VARIABLE public.avar;
+
+DROP TYPE xxtype;
+
+DROP TABLE xxtab;
+
+-- The variable can be shadowed by table or by alias
+CREATE TYPE public.svar_type AS (a int, b int, c int);
+CREATE VARIABLE public.svar AS public.svar_type;
+
+CREATE TABLE public.svar(a int, b int);
+
+INSERT INTO public.svar VALUES(10, 20);
+
+LET public.svar = (100, 200, 300);
+
+-- should be ok
+-- show table
+SELECT * FROM public.svar;
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+SELECT svar.a FROM public.svar;
+SELECT svar.* FROM public.svar;
+
+-- show variable
+SELECT public.svar;
+SELECT public.svar.c;
+SELECT (public.svar).*;
+
+-- the variable is shadowed, raise error
+SELECT public.svar.c FROM public.svar;
+
+-- can be fixed by alias
+SELECT public.svar.c FROM public.svar x;
+
+DROP VARIABLE public.svar;
+DROP TABLE public.svar;
+DROP TYPE public.svar_type;
+
+-- The sequence ident.* cannot be used by reference to session variable,
+-- and in this case, there is not collision
+CREATE SCHEMA vartest;
+SET SEARCH_PATH TO vartest;
+CREATE TABLE vartest_foo(a int, b int);
+INSERT INTO vartest_foo VALUES(10,20), (30,40);
+
+CREATE VARIABLE var1 AS vartest_foo;
+LET var1 = (100,200);
+
+-- should to fail
+SELECT var1.* FROM vartest_foo;
+
+-- should be ok
+SELECT var1.* FROM vartest_foo var1;
+
+-- should to fail
+SELECT count(var1.*) FROM vartest_foo;
+
+-- should be ok
+SELECT count(var1.*) FROM vartest_foo var1;
+
+SET SEARCH_PATH TO DEFAULT;
+DROP SCHEMA vartest CASCADE;
+
+CREATE TYPE ab AS (a integer, b integer);
+
+CREATE VARIABLE v_ab AS ab;
+
+CREATE TABLE v_ab (a integer, b integer);
+INSERT INTO v_ab VALUES(10,20);
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+CREATE SCHEMA v_ab;
+
+CREATE VARIABLE v_ab.a AS integer;
+
+-- we should see table
+SELECT v_ab.a FROM v_ab;
+
+DROP VARIABLE v_ab;
+DROP TABLE v_ab;
+DROP TYPE ab;
+DROP VARIABLE v_ab.a;
+DROP SCHEMA v_ab;
+
+CREATE TYPE t_am_type AS (b int);
+CREATE SCHEMA xxx_am;
+
+SET search_path TO public;
+
+CREATE VARIABLE xxx_am AS t_am_type;
+LET xxx_am = ROW(10);
+
+-- should be ok
+SELECT xxx_am;
+
+CREATE VARIABLE xxx_am.b AS int;
+LET :"DBNAME".xxx_am.b = 20;
+
+-- should be still ok
+SELECT xxx_am;
+
+-- should fail, the reference should be ambiguous
+SELECT xxx_am.b;
+
+-- enhanced references should be ok
+SELECT public.xxx_am.b;
+SELECT :"DBNAME".xxx_am.b;
+
+CREATE TABLE xxx_am(b int);
+INSERT INTO xxx_am VALUES(10);
+
+-- we should see table
+SELECT xxx_am.b FROM xxx_am;
+SELECT x.b FROM xxx_am x;
+
+DROP TABLE xxx_am;
+DROP VARIABLE public.xxx_am;
+DROP VARIABLE xxx_am.b;
+DROP SCHEMA xxx_am;
+
+CREATE SCHEMA :"DBNAME";
+
+CREATE VARIABLE :"DBNAME".:"DBNAME".:"DBNAME" AS t_am_type;
+CREATE VARIABLE :"DBNAME".:"DBNAME".b AS int;
+
+SET search_path TO :"DBNAME";
+
+-- should be ambiguous
+SELECT :"DBNAME".b;
+
+-- should be ambiguous too
+SELECT :"DBNAME".:"DBNAME".b;
+
+CREATE TABLE :"DBNAME"(b int);
+
+-- should be ok
+SELECT :"DBNAME".b FROM :"DBNAME";
+
+DROP TABLE :"DBNAME";
+
+DROP VARIABLE :"DBNAME".:"DBNAME".b;
+DROP VARIABLE :"DBNAME".:"DBNAME".:"DBNAME";
+DROP SCHEMA :"DBNAME";
+
+RESET search_path;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 9dc16940b9d..42d18ad0b91 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -1542,6 +1542,7 @@ LargeObjectDesc
Latch
LauncherLastStartTimesEntry
LerpFunc
+LetStmt
LexDescr
LexemeEntry
LexemeHashKey
@@ -2699,6 +2700,7 @@ SerializedTransactionState
Session
SessionBackupState
SessionEndType
+SessionVariableValue
SetConstraintState
SetConstraintStateData
SetConstraintTriggerData
@@ -2897,6 +2899,9 @@ SupportRequestRows
SupportRequestSelectivity
SupportRequestSimplify
SupportRequestWFuncMonotonic
+SVariable
+SVariableData
+SVariableState
Syn
SyncOps
SyncRepConfigData
--
2.49.0
[text/x-patch] v20250515-0001-Enhancing-catalog-for-support-session-variables-and-.patch (169.5K, ../../CAFj8pRCEjG005L=1vGbir-odYdcYxByOAeFVJ_K9eRcRF=MbNQ@mail.gmail.com/10-v20250515-0001-Enhancing-catalog-for-support-session-variables-and-.patch)
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From 9c3402dbb17a96459d46efcd6b552fc1e1b0aecd Mon Sep 17 00:00:00 2001
From: "[email protected]" <[email protected]>
Date: Fri, 19 Jan 2024 15:41:55 +0100
Subject: [PATCH 01/21] Enhancing catalog for support session variables and
related support
This patch introduces new system catalog table pg_variable. This table holds metadata about
session variables created by command CREATE VARIABLE, and dropped by command DROP VARIABLE.
Both commands are implemented by this patch. Possibility to change owner, schema or rename.
Access to session variables can be controlled by SELECT or UPDATE rights. Both rights are
introduced by this patch too.
This patch enhancing pg_dump and psql to support session variables. The changes are related
to system catalog.
This patch is not short, but the code is simple.
---
doc/src/sgml/catalogs.sgml | 121 +++++
doc/src/sgml/ddl.sgml | 40 +-
doc/src/sgml/func.sgml | 32 ++
doc/src/sgml/glossary.sgml | 15 +
doc/src/sgml/ref/allfiles.sgml | 3 +
.../sgml/ref/alter_default_privileges.sgml | 29 +-
doc/src/sgml/ref/alter_variable.sgml | 178 +++++++
doc/src/sgml/ref/comment.sgml | 1 +
doc/src/sgml/ref/create_schema.sgml | 12 +-
doc/src/sgml/ref/create_variable.sgml | 149 ++++++
doc/src/sgml/ref/drop_variable.sgml | 117 +++++
doc/src/sgml/ref/grant.sgml | 20 +-
doc/src/sgml/ref/psql-ref.sgml | 13 +
doc/src/sgml/ref/revoke.sgml | 8 +
doc/src/sgml/reference.sgml | 3 +
src/backend/catalog/Makefile | 1 +
src/backend/catalog/aclchk.c | 76 +++
src/backend/catalog/dependency.c | 6 +
src/backend/catalog/meson.build | 1 +
src/backend/catalog/namespace.c | 221 +++++++++
src/backend/catalog/objectaddress.c | 121 ++++-
src/backend/catalog/pg_shdepend.c | 2 +
src/backend/catalog/pg_variable.c | 251 ++++++++++
src/backend/commands/alter.c | 9 +
src/backend/commands/dropcmds.c | 4 +
src/backend/commands/event_trigger.c | 4 +
src/backend/commands/seclabel.c | 1 +
src/backend/commands/tablecmds.c | 41 ++
src/backend/commands/typecmds.c | 15 +
src/backend/parser/gram.y | 105 ++++-
src/backend/parser/parse_utilcmd.c | 12 +
src/backend/tcop/utility.c | 20 +
src/backend/utils/adt/acl.c | 221 +++++++++
src/backend/utils/cache/lsyscache.c | 113 +++++
src/bin/pg_dump/common.c | 3 +
src/bin/pg_dump/dumputils.c | 6 +
src/bin/pg_dump/pg_backup.h | 2 +
src/bin/pg_dump/pg_backup_archiver.c | 9 +
src/bin/pg_dump/pg_dump.c | 190 ++++++++
src/bin/pg_dump/pg_dump.h | 15 +
src/bin/pg_dump/pg_dump_sort.c | 7 +
src/bin/pg_dump/t/002_pg_dump.pl | 64 +++
src/bin/psql/command.c | 3 +
src/bin/psql/describe.c | 100 +++-
src/bin/psql/describe.h | 3 +
src/bin/psql/help.c | 1 +
src/bin/psql/tab-complete.in.c | 45 +-
src/include/catalog/Makefile | 3 +-
src/include/catalog/meson.build | 1 +
src/include/catalog/namespace.h | 6 +
src/include/catalog/pg_default_acl.h | 1 +
src/include/catalog/pg_proc.dat | 23 +
src/include/catalog/pg_variable.h | 81 ++++
src/include/nodes/parsenodes.h | 16 +
src/include/parser/kwlist.h | 2 +
src/include/tcop/cmdtaglist.h | 3 +
src/include/utils/acl.h | 1 +
src/include/utils/lsyscache.h | 9 +
src/test/regress/expected/dependency.out | 17 +
src/test/regress/expected/oidjoins.out | 4 +
src/test/regress/expected/psql.out | 50 ++
.../regress/expected/session_variables.out | 433 ++++++++++++++++++
src/test/regress/parallel_schedule | 2 +-
src/test/regress/sql/dependency.sql | 14 +
src/test/regress/sql/psql.sql | 21 +
src/test/regress/sql/session_variables.sql | 297 ++++++++++++
src/tools/pgindent/typedefs.list | 4 +
67 files changed, 3366 insertions(+), 35 deletions(-)
create mode 100644 doc/src/sgml/ref/alter_variable.sgml
create mode 100644 doc/src/sgml/ref/create_variable.sgml
create mode 100644 doc/src/sgml/ref/drop_variable.sgml
create mode 100644 src/backend/catalog/pg_variable.c
create mode 100644 src/include/catalog/pg_variable.h
create mode 100644 src/test/regress/expected/session_variables.out
create mode 100644 src/test/regress/sql/session_variables.sql
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index cbd4e40a320..fc562361792 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -369,6 +369,11 @@
<entry><link linkend="catalog-pg-user-mapping"><structname>pg_user_mapping</structname></link></entry>
<entry>mappings of users to foreign servers</entry>
</row>
+
+ <row>
+ <entry><link linkend="catalog-pg-variable"><structname>pg_variable</structname></link></entry>
+ <entry>session variables</entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -3362,6 +3367,7 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
<literal>T</literal> = type,
<literal>n</literal> = schema,
<literal>L</literal> = large object
+ <literal>V</literal> = session variable
</para></entry>
</row>
@@ -9779,4 +9785,119 @@ SCRAM-SHA-256$<replaceable><iteration count></replaceable>:<replaceable>&l
</table>
</sect1>
+ <sect1 id="catalog-pg-variable">
+ <title><structname>pg_variable</structname></title>
+
+ <indexterm zone="catalog-pg-variable">
+ <primary>pg_variable</primary>
+ </indexterm>
+
+ <para>
+ The catalog <structname>pg_variable</structname> stores information about
+ session variables.
+ </para>
+
+ <table>
+ <title><structname>pg_variable</structname> Columns</title>
+ <tgroup cols="1">
+ <thead>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ Column Type
+ </para>
+ <para>
+ Description
+ </para></entry>
+ </row>
+ </thead>
+
+ <tbody>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>oid</structfield> <type>oid</type>
+ </para>
+ <para>
+ Row identifier
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartype</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-type"><structname>pg_type</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the variable's data type
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varname</structfield> <type>name</type>
+ </para>
+ <para>
+ Name of the session variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varnamespace</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The OID of the namespace that contains this variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varowner</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-authid"><structname>pg_authid</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ Owner of the variable
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>vartypmod</structfield> <type>int4</type>
+ </para>
+ <para>
+ <structfield>vartypmod</structfield> records type-specific data
+ supplied at variable creation time (for example, the maximum
+ length of a <type>varchar</type> column). It is passed to
+ type-specific input functions and length coercion functions.
+ The value will generally be -1 for types that do not need <structfield>vartypmod</structfield>.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varcollation</structfield> <type>oid</type>
+ (references <link linkend="catalog-pg-collation"><structname>pg_collation</structname></link>.<structfield>oid</structfield>)
+ </para>
+ <para>
+ The defined collation of the variable, or zero if the variable is
+ not of a collatable data type.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>varacl</structfield> <type>aclitem[]</type>
+ </para>
+ <para>
+ Access privileges; see
+ <xref linkend="sql-grant"/> and
+ <xref linkend="sql-revoke"/>
+ for details
+ </para></entry>
+ </row>
+
+ </tbody>
+ </tgroup>
+ </table>
+ </sect1>
</chapter>
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index fcd1cb85352..66fa267facc 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -2015,6 +2015,7 @@ REVOKE ALL ON accounts FROM PUBLIC;
For sequences, this privilege also allows use of the
<function>currval</function> function.
For large objects, this privilege allows the object to be read.
+ For session variables, this privilege allows the object to be read.
</para>
</listitem>
</varlistentry>
@@ -2050,6 +2051,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<function>setval</function> functions.
For large objects, this privilege allows writing or truncating the
object.
+ For session variables, this privilege allows to set a value to the
+ object.
</para>
</listitem>
</varlistentry>
@@ -2293,7 +2296,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal> (and table-like objects),
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2308,7 +2312,8 @@ REVOKE ALL ON accounts FROM PUBLIC;
<literal>LARGE OBJECT</literal>,
<literal>SEQUENCE</literal>,
<literal>TABLE</literal>,
- table column
+ table column,
+ <literal>SESSION VARIABLE</literal>
</entry>
</row>
<row>
@@ -2495,6 +2500,12 @@ REVOKE ALL ON accounts FROM PUBLIC;
<entry><literal>U</literal></entry>
<entry><literal>\dT+</literal></entry>
</row>
+ <row>
+ <entry><literal>SESSION VARIABLE</literal></entry>
+ <entry><literal>rw</literal></entry>
+ <entry><literal>none</literal></entry>
+ <entry><literal>\dV+</literal></entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -5351,6 +5362,31 @@ EXPLAIN SELECT count(*) FROM measurement WHERE logdate >= DATE '2008-01-01';
</para>
</sect1>
+ <sect1 id="ddl-session-variables">
+ <title>Session Variables</title>
+
+ <indexterm zone="ddl-session-variables">
+ <primary>Session variables</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ </indexterm>
+
+ <para>
+ Session variables are database objects that can hold a value.
+ Session variables, like relations, exist within a schema and their access
+ is controlled via <command>GRANT</command> and <command>REVOKE</command>
+ commands. A session variable can be created by the <command>CREATE
+ VARIABLE</command> command.
+ </para>
+
+ <para>
+ The session variable holds value in session memory. This value is private
+ to each session and is released when the session ends.
+ </para>
+ </sect1>
+
<sect1 id="ddl-others">
<title>Other Database Objects</title>
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index b405525a465..0fdf613dc5e 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25602,6 +25602,25 @@ SELECT has_function_privilege('joeuser', 'myfunc(int, text)', 'execute');
</para></entry>
</row>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>has_session_variable_privilege</primary>
+ </indexterm>
+ <function>has_session_variable_privilege</function> (
+ <optional> <parameter>user</parameter> <type>name</type> or <type>oid</type>, </optional>
+ <parameter>session_variable</parameter> <type>text</type> or <type>oid</type>,
+ <parameter>privilege</parameter> <type>text</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Does user have privilege for session variable?
+ Allowable privilege types are
+ <literal>SELECT</literal>, and
+ <literal>UPDATE</literal>.
+ </para></entry>
+ </row>
+
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
@@ -26110,6 +26129,19 @@ SELECT relname FROM pg_class WHERE pg_table_is_visible(oid);
Is type (or domain) visible in search path?
</para></entry>
</row>
+
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_variable_is_visible</primary>
+ </indexterm>
+ <function>pg_variable_is_visible</function> ( <parameter>variable</parameter> <type>oid</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Is session variable visible in search path?
+ </para></entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml
index b88cac598e9..83b13f98f28 100644
--- a/doc/src/sgml/glossary.sgml
+++ b/doc/src/sgml/glossary.sgml
@@ -1708,6 +1708,21 @@
</glossdef>
</glossentry>
+ <glossentry id="glossary-session-variable">
+ <glossterm>Session variable</glossterm>
+ <glossdef>
+ <para>
+ A persistent database object that holds a value in session memory. This
+ value is private to each session and is released when the session ends.
+ Read or write access to session variables is controlled by privileges,
+ similar to other database objects.
+ </para>
+ <para>
+ For more information, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </glossdef>
+ </glossentry>
+
<glossentry id="glossary-shared-memory">
<glossterm>Shared memory</glossterm>
<glossdef>
diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index f5be638867a..2f67de3e21b 100644
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -47,6 +47,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY alterType SYSTEM "alter_type.sgml">
<!ENTITY alterUser SYSTEM "alter_user.sgml">
<!ENTITY alterUserMapping SYSTEM "alter_user_mapping.sgml">
+<!ENTITY alterVariable SYSTEM "alter_variable.sgml">
<!ENTITY alterView SYSTEM "alter_view.sgml">
<!ENTITY analyze SYSTEM "analyze.sgml">
<!ENTITY begin SYSTEM "begin.sgml">
@@ -99,6 +100,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY createType SYSTEM "create_type.sgml">
<!ENTITY createUser SYSTEM "create_user.sgml">
<!ENTITY createUserMapping SYSTEM "create_user_mapping.sgml">
+<!ENTITY createVariable SYSTEM "create_variable.sgml">
<!ENTITY createView SYSTEM "create_view.sgml">
<!ENTITY deallocate SYSTEM "deallocate.sgml">
<!ENTITY declare SYSTEM "declare.sgml">
@@ -147,6 +149,7 @@ Complete list of usable sgml source files in this directory.
<!ENTITY dropType SYSTEM "drop_type.sgml">
<!ENTITY dropUser SYSTEM "drop_user.sgml">
<!ENTITY dropUserMapping SYSTEM "drop_user_mapping.sgml">
+<!ENTITY dropVariable SYSTEM "drop_variable.sgml">
<!ENTITY dropView SYSTEM "drop_view.sgml">
<!ENTITY end SYSTEM "end.sgml">
<!ENTITY execute SYSTEM "execute.sgml">
diff --git a/doc/src/sgml/ref/alter_default_privileges.sgml b/doc/src/sgml/ref/alter_default_privileges.sgml
index 6acd0f1df91..bc73817061f 100644
--- a/doc/src/sgml/ref/alter_default_privileges.sgml
+++ b/doc/src/sgml/ref/alter_default_privileges.sgml
@@ -56,6 +56,11 @@ GRANT { { SELECT | UPDATE }
ON LARGE OBJECTS
TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+GRANT { { SELECT | UPDATE }
+ [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ TO { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...] [ WITH GRANT OPTION ]
+
REVOKE [ GRANT OPTION FOR ]
{ { SELECT | INSERT | UPDATE | DELETE | TRUNCATE | REFERENCES | TRIGGER | MAINTAIN }
[, ...] | ALL [ PRIVILEGES ] }
@@ -95,6 +100,14 @@ REVOKE [ GRANT OPTION FOR ]
ON LARGE OBJECTS
FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
[ CASCADE | RESTRICT ]
+
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE }
+ [, ...] | ALL [ PRIVILEGES ] }
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON VARIABLES
+ FROM { [ GROUP ] <replaceable class="parameter">role_name</replaceable> | PUBLIC } [, ...]
+ [ CASCADE | RESTRICT ]
</synopsis>
</refsynopsisdiv>
@@ -129,14 +142,14 @@ REVOKE [ GRANT OPTION FOR ]
<para>
Currently,
only the privileges for schemas, tables (including views and foreign
- tables), sequences, functions, types (including domains), and large objects
- can be altered. For this command, functions include aggregates and procedures.
- The words <literal>FUNCTIONS</literal> and <literal>ROUTINES</literal> are
- equivalent in this command. (<literal>ROUTINES</literal> is preferred
- going forward as the standard term for functions and procedures taken
- together. In earlier PostgreSQL releases, only the
- word <literal>FUNCTIONS</literal> was allowed. It is not possible to set
- default privileges for functions and procedures separately.)
+ tables), sequences, functions, types (including domains), large objects
+ and session variables can be altered. For this command, functions include
+ aggregates and procedures. The words <literal>FUNCTIONS</literal> and
+ <literal>ROUTINES</literal> are equivalent in this command.
+ (<literal>ROUTINES</literal> is preferred going forward as the standard term
+ for functions and procedures taken together. In earlier PostgreSQL releases,
+ only the word <literal>FUNCTIONS</literal> was allowed. It is not possible
+ to set default privileges for functions and procedures separately.)
</para>
<para>
diff --git a/doc/src/sgml/ref/alter_variable.sgml b/doc/src/sgml/ref/alter_variable.sgml
new file mode 100644
index 00000000000..96d2586423e
--- /dev/null
+++ b/doc/src/sgml/ref/alter_variable.sgml
@@ -0,0 +1,178 @@
+<!--
+doc/src/sgml/ref/alter_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-altervariable">
+ <indexterm zone="sql-altervariable">
+ <primary>ALTER VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>altering</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>ALTER VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>ALTER VARIABLE</refname>
+ <refpurpose>
+ change the definition of a session variable
+ </refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> OWNER TO { <replaceable class="parameter">new_owner</replaceable> | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> RENAME TO <replaceable class="parameter">new_name</replaceable>
+ALTER VARIABLE <replaceable class="parameter">name</replaceable> SET SCHEMA <replaceable class="parameter">new_schema</replaceable>
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>ALTER VARIABLE</command> command changes the definition of an
+ existing session variable. There are several subforms:
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>OWNER</literal></term>
+ <listitem>
+ <para>
+ This form changes the owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RENAME</literal></term>
+ <listitem>
+ <para>
+ This form changes the name of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>SET SCHEMA</literal></term>
+ <listitem>
+ <para>
+ This form moves the session variable into another schema.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </para>
+
+ <para>
+ Only the owner or a superuser is allowed to alter a session variable.
+ In order to move a session variable from one schema to another, the user
+ must also have the <literal>CREATE</literal> privilege on the new schema (or
+ be a superuser).
+
+ In order to move the session variable ownership from one role to another,
+ the user must also be a direct or indirect member of the new
+ owning role, and that role must have the <literal>CREATE</literal> privilege
+ on the session variable's schema (or be a superuser). These restrictions
+ enforce that altering the owner doesn't do anything you couldn't do by
+ dropping and recreating the session variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <para>
+ <variablelist>
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name (possibly schema-qualified) of the existing session variable
+ to alter.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_owner</replaceable></term>
+ <listitem>
+ <para>
+ The user name of the new owner of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_name</replaceable></term>
+ <listitem>
+ <para>
+ The new name for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">new_schema</replaceable></term>
+ <listitem>
+ <para>
+ The new schema for the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To rename a session variable:
+<programlisting>
+ALTER VARIABLE foo RENAME TO boo;
+</programlisting>
+ </para>
+
+ <para>
+ To change the owner of the session variable <literal>boo</literal> to
+ <literal>joe</literal>:
+<programlisting>
+ALTER VARIABLE boo OWNER TO joe;
+</programlisting>
+ </para>
+
+ <para>
+ To change the schema of the session variable <literal>boo</literal> to
+ <literal>private</literal>:
+<programlisting>
+ALTER VARIABLE boo SET SCHEMA private;
+</programlisting>
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ Session variables and this command in particular are a PostgreSQL extension.
+ </para>
+ </refsect1>
+
+ <refsect1 id="sql-altervariable-see-also">
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-createvariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+</refentry>
diff --git a/doc/src/sgml/ref/comment.sgml b/doc/src/sgml/ref/comment.sgml
index 5b43c56b133..21cd80818fb 100644
--- a/doc/src/sgml/ref/comment.sgml
+++ b/doc/src/sgml/ref/comment.sgml
@@ -65,6 +65,7 @@ COMMENT ON
TRANSFORM FOR <replaceable>type_name</replaceable> LANGUAGE <replaceable>lang_name</replaceable> |
TRIGGER <replaceable class="parameter">trigger_name</replaceable> ON <replaceable class="parameter">table_name</replaceable> |
TYPE <replaceable class="parameter">object_name</replaceable> |
+ VARIABLE <replaceable class="parameter">object_name</replaceable> |
VIEW <replaceable class="parameter">object_name</replaceable>
} IS { <replaceable class="parameter">string_literal</replaceable> | NULL }
diff --git a/doc/src/sgml/ref/create_schema.sgml b/doc/src/sgml/ref/create_schema.sgml
index ed69298ccc6..d2bb265209b 100644
--- a/doc/src/sgml/ref/create_schema.sgml
+++ b/doc/src/sgml/ref/create_schema.sgml
@@ -103,9 +103,10 @@ CREATE SCHEMA IF NOT EXISTS AUTHORIZATION <replaceable class="parameter">role_sp
schema. Currently, only <command>CREATE
TABLE</command>, <command>CREATE VIEW</command>, <command>CREATE
INDEX</command>, <command>CREATE SEQUENCE</command>, <command>CREATE
- TRIGGER</command> and <command>GRANT</command> are accepted as clauses
- within <command>CREATE SCHEMA</command>. Other kinds of objects may
- be created in separate commands after the schema is created.
+ TRIGGER</command>, <command>GRANT</command> and <command>CREATE
+ VARIABLE</command> are accepted as clauses within <command>CREATE
+ SCHEMA</command>. Other kinds of objects may be created in separate
+ commands after the schema is created.
</para>
</listitem>
</varlistentry>
@@ -214,6 +215,11 @@ CREATE VIEW hollywood.winners AS
The <literal>IF NOT EXISTS</literal> option is a
<productname>PostgreSQL</productname> extension.
</para>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
</refsect1>
<refsect1>
diff --git a/doc/src/sgml/ref/create_variable.sgml b/doc/src/sgml/ref/create_variable.sgml
new file mode 100644
index 00000000000..6e988f2e472
--- /dev/null
+++ b/doc/src/sgml/ref/create_variable.sgml
@@ -0,0 +1,149 @@
+<!--
+doc/src/sgml/ref/create_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-createvariable">
+ <indexterm zone="sql-createvariable">
+ <primary>CREATE VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>defining</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>CREATE VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>CREATE VARIABLE</refname>
+ <refpurpose>define a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+CREATE VARIABLE [ IF NOT EXISTS ] <replaceable class="parameter">name</replaceable> [ AS ] <replaceable class="parameter">data_type</replaceable> [ COLLATE <replaceable class="parameter">collation</replaceable> ]
+</synopsis>
+ </refsynopsisdiv>
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command creates a session variable.
+ Session variables, like relations, exist within a schema and their access is
+ controlled via the commands <command>GRANT</command> and <command>REVOKE</command>.
+ </para>
+
+ <para>
+ The value of a session variable is local to the current session. Retrieving
+ a session variable's value returns NULL, unless its value is set to
+ something else in the current session with a <command>LET</command> command.
+ The content of a session variable is not transactional. This is the same as
+ regular variables in procedural languages.
+ </para>
+
+ <para>
+ Session variables are retrieved by the <command>SELECT</command>
+ command. Their value is set with the <command>LET</command> command.
+ </para>
+
+ <note>
+ <para>
+ Session variables can be <quote>shadowed</quote> by other identifiers.
+ For details, see <xref linkend="ddl-session-variables"/>.
+ </para>
+ </note>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+
+ <varlistentry id="sql-createvariable-if-not-exists">
+ <term><literal>IF NOT EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the name already exists. A notice is issued in
+ this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-name">
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-data_type">
+ <term><replaceable class="parameter">data_type</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of the data type of the session
+ variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="sql-createvariable-collate">
+ <term><literal>COLLATE <replaceable>collation</replaceable></literal></term>
+ <listitem>
+ <para>
+ The <literal>COLLATE</literal> clause assigns a collation to the session
+ variable (which must be of a collatable data type). If not specified,
+ the data type's default collation is used.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para>
+ Use the <command>DROP VARIABLE</command> command to remove a session
+ variable.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ Create an date session variable <literal>var1</literal>:
+<programlisting>
+CREATE VARIABLE var1 AS date;
+</programlisting>
+ </para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>CREATE VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-dropvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/drop_variable.sgml b/doc/src/sgml/ref/drop_variable.sgml
new file mode 100644
index 00000000000..5bdb3560f0b
--- /dev/null
+++ b/doc/src/sgml/ref/drop_variable.sgml
@@ -0,0 +1,117 @@
+<!--
+doc/src/sgml/ref/drop_variable.sgml
+PostgreSQL documentation
+-->
+
+<refentry id="sql-dropvariable">
+ <indexterm zone="sql-dropvariable">
+ <primary>DROP VARIABLE</primary>
+ </indexterm>
+
+ <indexterm>
+ <primary>session variable</primary>
+ <secondary>removing</secondary>
+ </indexterm>
+
+ <refmeta>
+ <refentrytitle>DROP VARIABLE</refentrytitle>
+ <manvolnum>7</manvolnum>
+ <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+ <refname>DROP VARIABLE</refname>
+ <refpurpose>remove a session variable</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+<synopsis>
+DROP VARIABLE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [, ...] [ CASCADE | RESTRICT ]
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>
+ <command>DROP VARIABLE</command> removes a session variable.
+ A session variable can only be removed by its owner or a superuser.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Parameters</title>
+
+ <variablelist>
+ <varlistentry>
+ <term><literal>IF EXISTS</literal></term>
+ <listitem>
+ <para>
+ Do not throw an error if the session variable does not exist. A notice is
+ issued in this case.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><replaceable class="parameter">name</replaceable></term>
+ <listitem>
+ <para>
+ The name, optionally schema-qualified, of a session variable.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>CASCADE</literal></term>
+ <listitem>
+ <para>
+ Automatically drop objects that depend on the session variable (such as
+ views), and in turn all objects that depend on those objects
+ (see <xref linkend="ddl-depend"/>).
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><literal>RESTRICT</literal></term>
+ <listitem>
+ <para>
+ Refuse to drop the session variable if any objects depend on it. This is
+ the default.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>
+ To remove the session variable <literal>var1</literal>:
+
+<programlisting>
+DROP VARIABLE var1;
+</programlisting></para>
+ </refsect1>
+
+ <refsect1>
+ <title>Compatibility</title>
+
+ <para>
+ The <command>DROP VARIABLE</command> command is a
+ <productname>PostgreSQL</productname> extension.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <simplelist type="inline">
+ <member><xref linkend="sql-altervariable"/></member>
+ <member><xref linkend="sql-createvariable"/></member>
+ </simplelist>
+ </refsect1>
+
+</refentry>
diff --git a/doc/src/sgml/ref/grant.sgml b/doc/src/sgml/ref/grant.sgml
index 999f657d5c0..c11860fa200 100644
--- a/doc/src/sgml/ref/grant.sgml
+++ b/doc/src/sgml/ref/grant.sgml
@@ -101,6 +101,12 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
[ WITH { ADMIN | INHERIT | SET } { OPTION | TRUE | FALSE } ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+GRANT { SELECT | UPDATE | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ TO <replaceable class="parameter">role_specification</replaceable> [, ...] [ WITH GRANT OPTION ]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
@@ -119,8 +125,8 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
that grants privileges on a database object (table, column, view,
foreign table, sequence, database, foreign-data wrapper, foreign server,
function, procedure, procedural language, large object, configuration
- parameter, schema, tablespace, or type), and one that grants
- membership in a role. These variants are similar in many ways, but
+ parameter, schema, session variable, tablespace, or type), and one that
+ grants membership in a role. These variants are similar in many ways, but
they are different enough to be described separately.
</para>
@@ -236,9 +242,9 @@ GRANT <replaceable class="parameter">role_name</replaceable> [, ...] TO <replace
<para>
There is also an option to grant privileges on all objects of the same
type within one or more schemas. This functionality is currently supported
- only for tables, sequences, functions, and procedures. <literal>ALL
- TABLES</literal> also affects views and foreign tables, just like the
- specific-object <command>GRANT</command> command. <literal>ALL
+ only for tables, sequences, functions, procedures and variables.
+ <literal>ALL TABLES</literal> also affects views and foreign tables, just
+ like the specific-object <command>GRANT</command> command. <literal>ALL
FUNCTIONS</literal> also affects aggregate and window functions, but not
procedures, again just like the specific-object <command>GRANT</command>
command. Use <literal>ALL ROUTINES</literal> to include procedures.
@@ -518,8 +524,8 @@ GRANT admins TO joe;
</para>
<para>
- Privileges on databases, tablespaces, schemas, languages, and
- configuration parameters are
+ Privileges on databases, tablespaces, schemas, languages, session variables
+ and configuration parameters are
<productname>PostgreSQL</productname> extensions.
</para>
</refsect1>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 8f7d8758ca0..f86966f5128 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -2135,6 +2135,19 @@ SELECT $1 \parse stmt1
</listitem>
</varlistentry>
+ <varlistentry id="app-psql-meta-command-dv">
+ <term><literal>\dV[+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
+ <listitem>
+ <para>
+ Lists session variables.
+ If <replaceable class="parameter">pattern</replaceable> is
+ specified, only session variables whose names match the pattern are listed.
+ If the form <literal>\dV+</literal> is used, additional information
+ about each variable is shown, like access privileges and description.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="app-psql-meta-command-du">
<term><literal>\du[Sx+] [ <link linkend="app-psql-patterns"><replaceable class="parameter">pattern</replaceable></link> ]</literal></term>
<listitem>
diff --git a/doc/src/sgml/ref/revoke.sgml b/doc/src/sgml/ref/revoke.sgml
index 8df492281a1..760fddb7c20 100644
--- a/doc/src/sgml/ref/revoke.sgml
+++ b/doc/src/sgml/ref/revoke.sgml
@@ -130,6 +130,14 @@ REVOKE [ { ADMIN | INHERIT | SET } OPTION FOR ]
[ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
[ CASCADE | RESTRICT ]
+REVOKE [ GRANT OPTION FOR ]
+ { { SELECT | UPDATE } [, ...] | ALL [ PRIVILEGES ] }
+ ON { VARIABLE <replaceable>variable_name</replaceable> [, ...]
+ | ALL VARIABLES IN SCHEMA <replaceable class="parameter">schema_name</replaceable> [, ...] }
+ FROM { <replaceable class="parameter">role_specification</replaceable> | PUBLIC } [, ...]
+ [ GRANTED BY <replaceable class="parameter">role_specification</replaceable> ]
+ [ CASCADE | RESTRICT ]
+
<phrase>where <replaceable class="parameter">role_specification</replaceable> can be:</phrase>
[ GROUP ] <replaceable class="parameter">role_name</replaceable>
diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index ff85ace83fc..25578f3946c 100644
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -75,6 +75,7 @@
&alterType;
&alterUser;
&alterUserMapping;
+ &alterVariable;
&alterView;
&analyze;
&begin;
@@ -127,6 +128,7 @@
&createType;
&createUser;
&createUserMapping;
+ &createVariable;
&createView;
&deallocate;
&declare;
@@ -175,6 +177,7 @@
&dropType;
&dropUser;
&dropUserMapping;
+ &dropVariable;
&dropView;
&end;
&execute;
diff --git a/src/backend/catalog/Makefile b/src/backend/catalog/Makefile
index c090094ed08..2c20d60db19 100644
--- a/src/backend/catalog/Makefile
+++ b/src/backend/catalog/Makefile
@@ -45,6 +45,7 @@ OBJS = \
pg_shdepend.o \
pg_subscription.o \
pg_type.o \
+ pg_variable.o \
storage.o \
toasting.o
diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 9ca8a88dc91..587be8c70c8 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -64,6 +64,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -291,6 +292,9 @@ restrict_and_check_grant(bool is_grant, AclMode avail_goptions, bool all_privs,
case OBJECT_PARAMETER_ACL:
whole_mask = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ whole_mask = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", objtype);
/* not reached, but keep compiler quiet */
@@ -535,6 +539,10 @@ ExecuteGrantStmt(GrantStmt *stmt)
all_privileges = ACL_ALL_RIGHTS_PARAMETER_ACL;
errormsg = gettext_noop("invalid privilege type %s for parameter");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) stmt->objtype);
@@ -640,6 +648,9 @@ ExecGrantStmt_oids(InternalGrant *istmt)
case OBJECT_PARAMETER_ACL:
ExecGrant_Parameter(istmt);
break;
+ case OBJECT_VARIABLE:
+ ExecGrant_common(istmt, VariableRelationId, ACL_ALL_RIGHTS_VARIABLE, NULL);
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) istmt->objtype);
@@ -760,6 +771,18 @@ objectNamesToOids(ObjectType objtype, List *objnames, bool is_grant)
objects = lappend_oid(objects, parameterId);
}
break;
+
+ case OBJECT_VARIABLE:
+ foreach_node(RangeVar, varvar, objnames)
+ {
+ Oid relOid;
+
+ relOid = LookupVariable(varvar->schemaname,
+ varvar->relname,
+ false);
+ objects = lappend_oid(objects, relOid);
+ }
+ break;
}
return objects;
@@ -846,6 +869,32 @@ objectsInSchemaToOids(ObjectType objtype, List *nspnames)
table_close(rel, AccessShareLock);
}
break;
+ case OBJECT_VARIABLE:
+ {
+ ScanKeyData key;
+ Relation rel;
+ TableScanDesc scan;
+ HeapTuple tuple;
+
+ ScanKeyInit(&key,
+ Anum_pg_variable_varnamespace,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(namespaceId));
+
+ rel = table_open(VariableRelationId, AccessShareLock);
+ scan = table_beginscan_catalog(rel, 1, &key);
+
+ while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
+ {
+ Oid oid = ((Form_pg_proc) GETSTRUCT(tuple))->oid;
+
+ objects = lappend_oid(objects, oid);
+ }
+
+ table_endscan(scan);
+ table_close(rel, AccessShareLock);
+ }
+ break;
default:
/* should not happen */
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
@@ -1009,6 +1058,10 @@ ExecAlterDefaultPrivilegesStmt(ParseState *pstate, AlterDefaultPrivilegesStmt *s
all_privileges = ACL_ALL_RIGHTS_LARGEOBJECT;
errormsg = gettext_noop("invalid privilege type %s for large object");
break;
+ case OBJECT_VARIABLE:
+ all_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ errormsg = gettext_noop("invalid privilege type %s for session variable");
+ break;
default:
elog(ERROR, "unrecognized GrantStmt.objtype: %d",
(int) action->objtype);
@@ -1209,6 +1262,11 @@ SetDefaultACL(InternalDefaultACL *iacls)
if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
this_privileges = ACL_ALL_RIGHTS_LARGEOBJECT;
break;
+ case OBJECT_VARIABLE:
+ objtype = DEFACLOBJ_VARIABLE;
+ if (iacls->all_privs && this_privileges == ACL_NO_RIGHTS)
+ this_privileges = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d",
@@ -1456,6 +1514,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case DEFACLOBJ_LARGEOBJECT:
iacls.objtype = OBJECT_LARGEOBJECT;
break;
+ case DEFACLOBJ_VARIABLE:
+ iacls.objtype = OBJECT_VARIABLE;
+ break;
default:
/* Shouldn't get here */
elog(ERROR, "unexpected default ACL type: %d",
@@ -1516,6 +1577,9 @@ RemoveRoleFromObjectACL(Oid roleid, Oid classid, Oid objid)
case ParameterAclRelationId:
istmt.objtype = OBJECT_PARAMETER_ACL;
break;
+ case VariableRelationId:
+ istmt.objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unexpected object class %u", classid);
break;
@@ -2749,6 +2813,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("permission denied for type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("permission denied for session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("permission denied for view %s");
break;
@@ -2860,6 +2927,9 @@ aclcheck_error(AclResult aclerr, ObjectType objtype,
case OBJECT_TYPE:
msg = gettext_noop("must be owner of type %s");
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("must be owner of session variable %s");
+ break;
case OBJECT_VIEW:
msg = gettext_noop("must be owner of view %s");
break;
@@ -3008,6 +3078,8 @@ pg_aclmask(ObjectType objtype, Oid object_oid, AttrNumber attnum, Oid roleid,
return ACL_NO_RIGHTS;
case OBJECT_TYPE:
return object_aclmask(TypeRelationId, object_oid, roleid, mask, how);
+ case OBJECT_VARIABLE:
+ return object_aclmask(VariableRelationId, object_oid, roleid, mask, how);
default:
elog(ERROR, "unrecognized object type: %d",
(int) objtype);
@@ -4271,6 +4343,10 @@ get_user_default_acl(ObjectType objtype, Oid ownerId, Oid nsp_oid)
defaclobjtype = DEFACLOBJ_LARGEOBJECT;
break;
+ case OBJECT_VARIABLE:
+ defaclobjtype = DEFACLOBJ_VARIABLE;
+ break;
+
default:
return NULL;
}
diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 18316a3968b..9e0f648b74f 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -65,12 +65,14 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/comment.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "commands/extension.h"
#include "commands/policy.h"
#include "commands/publicationcmds.h"
+#include "commands/schemacmds.h"
#include "commands/seclabel.h"
#include "commands/sequence.h"
#include "commands/trigger.h"
@@ -1444,6 +1446,10 @@ doDeletion(const ObjectAddress *object, int flags)
RemovePublicationById(object->objectId);
break;
+ case VariableRelationId:
+ DropVariableById(object->objectId);
+ break;
+
case CastRelationId:
case CollationRelationId:
case ConversionRelationId:
diff --git a/src/backend/catalog/meson.build b/src/backend/catalog/meson.build
index 1958ea9238a..ed44c877fca 100644
--- a/src/backend/catalog/meson.build
+++ b/src/backend/catalog/meson.build
@@ -32,6 +32,7 @@ backend_sources += files(
'pg_shdepend.c',
'pg_subscription.c',
'pg_type.c',
+ 'pg_variable.c',
'storage.c',
'toasting.c',
)
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index d97d632a7ef..4307cad15c7 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "common/hashfn_unstable.h"
#include "funcapi.h"
@@ -225,6 +226,7 @@ static bool TSParserIsVisibleExt(Oid prsId, bool *is_missing);
static bool TSDictionaryIsVisibleExt(Oid dictId, bool *is_missing);
static bool TSTemplateIsVisibleExt(Oid tmplId, bool *is_missing);
static bool TSConfigIsVisibleExt(Oid cfgid, bool *is_missing);
+static bool VariableIsVisibleExt(Oid varid, bool *is_missing);
static void recomputeNamespacePath(void);
static void AccessTempTableNamespace(bool force);
static void InitTempTableNamespace(void);
@@ -986,6 +988,84 @@ RelationIsVisibleExt(Oid relid, bool *is_missing)
return visible;
}
+/*
+ * VariableIsVisible
+ * Determine whether a variable (identified by OID) is visible in the
+ * current search path. Visible means "would be found by searching
+ * for the unqualified variable name".
+ */
+bool
+VariableIsVisible(Oid varid)
+{
+ return VariableIsVisibleExt(varid, NULL);
+}
+
+/*
+ * VariableIsVisibleExt
+ * As above, but if the variable isn't found and is_missing is not NULL,
+ * then set *is_missing = true and return false, instead of throwing
+ * an error. (Caller must initialize *is_missing = false.)
+ */
+static bool
+VariableIsVisibleExt(Oid varid, bool *is_missing)
+{
+ HeapTuple vartup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+ bool visible;
+
+ vartup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+ if (!HeapTupleIsValid(vartup))
+ {
+ if (is_missing != NULL)
+ {
+ *is_missing = true;
+ return false;
+ }
+
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+ }
+ varform = (Form_pg_variable) GETSTRUCT(vartup);
+
+ recomputeNamespacePath();
+
+ /*
+ * Quick check: if it ain't in the path at all, it ain't visible. We
+ * don't expect usage of session variables in the system namespace.
+ */
+ varnamespace = varform->varnamespace;
+ if (!list_member_oid(activeSearchPath, varnamespace))
+ visible = false;
+ else
+ {
+ /*
+ * If it is in the path, it might still not be visible; it could be
+ * hidden by another variable of the same name earlier in the path. So
+ * we must do a slow check for conflicting relations.
+ */
+ char *varname = NameStr(varform->varname);
+
+ visible = false;
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ if (namespaceId == varnamespace)
+ {
+ /* found it first in path */
+ visible = true;
+ break;
+ }
+ if (OidIsValid(get_varname_varid(varname, namespaceId)))
+ {
+ /* found something else first in path */
+ break;
+ }
+ }
+ }
+
+ ReleaseSysCache(vartup);
+
+ return visible;
+}
/*
* TypenameGetTypid
@@ -3289,6 +3369,133 @@ TSConfigIsVisibleExt(Oid cfgid, bool *is_missing)
return visible;
}
+/*
+ * Returns oid of session variable specified by possibly qualified identifier.
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariable(const char *nspname,
+ const char *varname,
+ bool missing_ok)
+{
+ Oid varoid = InvalidOid;
+
+ if (nspname)
+ {
+ Oid namespaceId = LookupExplicitNamespace(nspname, missing_ok);
+
+ /* if nspname is a known namespace, the variable must be there */
+ if (OidIsValid(namespaceId))
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+ }
+ }
+ else
+ {
+ /* iterate over the schemas on the search_path */
+ recomputeNamespacePath();
+
+ foreach_oid(namespaceId, activeSearchPath)
+ {
+ varoid = GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(namespaceId));
+
+ if (OidIsValid(varoid))
+ break;
+ }
+ }
+
+ if (!OidIsValid(varoid) && !missing_ok)
+ {
+ if (nspname)
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s.%s\" does not exist",
+ nspname, varname)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_UNDEFINED_OBJECT),
+ errmsg("session variable \"%s\" does not exist",
+ varname)));
+ }
+
+ return varoid;
+}
+
+/*
+ * Returns oid of session variable specified by possibly qualified identifier
+ *
+ * If not found, returns InvalidOid if missing_ok, else throws error.
+ */
+Oid
+LookupVariableFromNameList(List *names,
+ bool missing_ok)
+{
+ char *catname = NULL;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ switch (list_length(names))
+ {
+ case 1:
+ varname = strVal(linitial(names));
+ break;
+ case 2:
+ nspname = strVal(linitial(names));
+ varname = strVal(lsecond(names));
+ break;
+ case 3:
+ catname = strVal(linitial(names));
+ nspname = strVal(lsecond(names));
+ varname = strVal(lthird(names));
+
+ /* check catalog name */
+ if (strcmp(catname, get_database_name(MyDatabaseId)) != 0)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cross-database references are not implemented: %s",
+ NameListToString(names))));
+ break;
+ default:
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("improper session variable name (too many dotted names): %s",
+ NameListToString(names))));
+ break;
+ }
+
+ return LookupVariable(nspname, varname, missing_ok);
+}
+
+/*
+ * The input list contains names with indirection expressions used as the left
+ * part of LET statement. The following routine returns a new list with only
+ * initial strings (names) - without indirection expressions.
+ */
+List *
+NamesFromList(List *names)
+{
+ ListCell *l;
+ List *result = NIL;
+
+ foreach(l, names)
+ {
+ Node *n = lfirst(l);
+
+ if (IsA(n, String))
+ {
+ result = lappend(result, n);
+ }
+ else
+ break;
+ }
+
+ return result;
+}
/*
* DeconstructQualifiedName
@@ -5085,3 +5292,17 @@ pg_is_other_temp_schema(PG_FUNCTION_ARGS)
PG_RETURN_BOOL(isOtherTempNamespace(oid));
}
+
+Datum
+pg_variable_is_visible(PG_FUNCTION_ARGS)
+{
+ Oid oid = PG_GETARG_OID(0);
+ bool result;
+ bool is_missing = false;
+
+ result = VariableIsVisibleExt(oid, &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+ PG_RETURN_BOOL(result);
+}
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index b63fd57dc04..444892ad6ba 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -62,6 +62,7 @@
#include "catalog/pg_ts_template.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
@@ -636,6 +637,20 @@ static const ObjectPropertyType ObjectProperty[] =
OBJECT_USER_MAPPING,
false
},
+ {
+ "session variable",
+ VariableRelationId,
+ VariableOidIndexId,
+ VARIABLEOID,
+ VARIABLENAMENSP,
+ Anum_pg_variable_oid,
+ Anum_pg_variable_varname,
+ Anum_pg_variable_varnamespace,
+ Anum_pg_variable_varowner,
+ Anum_pg_variable_varacl,
+ OBJECT_VARIABLE,
+ true
+ }
};
/*
@@ -831,6 +846,9 @@ static const struct object_type_map
},
{
"statistics object", OBJECT_STATISTIC_EXT
+ },
+ {
+ "session variable", OBJECT_VARIABLE
}
};
@@ -856,6 +874,7 @@ static ObjectAddress get_object_address_attrdef(ObjectType objtype,
bool missing_ok);
static ObjectAddress get_object_address_type(ObjectType objtype,
TypeName *typename, bool missing_ok);
+static ObjectAddress get_object_address_variable(List *object, bool missing_ok);
static ObjectAddress get_object_address_opcf(ObjectType objtype, List *object,
bool missing_ok);
static ObjectAddress get_object_address_opf_member(ObjectType objtype,
@@ -1127,6 +1146,9 @@ get_object_address(ObjectType objtype, Node *object,
missing_ok);
address.objectSubId = 0;
break;
+ case OBJECT_VARIABLE:
+ address = get_object_address_variable(castNode(List, object), missing_ok);
+ break;
/* no default, to let compiler warn about missing case */
}
@@ -2008,17 +2030,21 @@ get_object_address_defacl(List *object, bool missing_ok)
case DEFACLOBJ_LARGEOBJECT:
objtype_str = "large objects";
break;
+ case DEFACLOBJ_VARIABLE:
+ objtype_str = "variables";
+ break;
default:
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized default ACL object type \"%c\"", objtype),
- errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
+ errhint("Valid object types are \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\", \"%c\".",
DEFACLOBJ_RELATION,
DEFACLOBJ_SEQUENCE,
DEFACLOBJ_FUNCTION,
DEFACLOBJ_TYPE,
DEFACLOBJ_NAMESPACE,
- DEFACLOBJ_LARGEOBJECT)));
+ DEFACLOBJ_LARGEOBJECT,
+ DEFACLOBJ_VARIABLE)));
}
/*
@@ -2102,6 +2128,24 @@ textarray_to_strvaluelist(ArrayType *arr)
return list;
}
+/*
+ * Find the ObjectAddress for a session variable
+ */
+static ObjectAddress
+get_object_address_variable(List *object, bool missing_ok)
+{
+ ObjectAddress address;
+ char *nspname = NULL;
+ char *varname = NULL;
+
+ ObjectAddressSet(address, VariableRelationId, InvalidOid);
+
+ DeconstructQualifiedName(object, &nspname, &varname);
+ address.objectId = LookupVariable(nspname, varname, missing_ok);
+
+ return address;
+}
+
/*
* SQL-callable version of get_object_address
*/
@@ -2296,6 +2340,7 @@ pg_get_object_address(PG_FUNCTION_ARGS)
case OBJECT_TABCONSTRAINT:
case OBJECT_OPCLASS:
case OBJECT_OPFAMILY:
+ case OBJECT_VARIABLE:
objnode = (Node *) name;
break;
case OBJECT_ACCESS_METHOD:
@@ -2467,6 +2512,7 @@ check_object_ownership(Oid roleid, ObjectType objtype, ObjectAddress address,
case OBJECT_STATISTIC_EXT:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
if (!object_ownercheck(address.classId, address.objectId, roleid))
aclcheck_error(ACLCHECK_NOT_OWNER, objtype,
NameListToString(castNode(List, object)));
@@ -3496,6 +3542,32 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
break;
}
+ case VariableRelationId:
+ {
+ char *nspname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ if (VariableIsVisible(object->objectId))
+ nspname = NULL;
+ else
+ nspname = get_namespace_name(varform->varnamespace);
+
+ appendStringInfo(&buffer, _("session variable %s"),
+ quote_qualified_identifier(nspname,
+ NameStr(varform->varname)));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
case TSParserRelationId:
{
HeapTuple tup;
@@ -3854,6 +3926,16 @@ getObjectDescription(const ObjectAddress *object, bool missing_ok)
_("default privileges on new large objects belonging to role %s"),
rolename);
break;
+ case DEFACLOBJ_VARIABLE:
+ if (nspname)
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s in schema %s"),
+ rolename, nspname);
+ else
+ appendStringInfo(&buffer,
+ _("default privileges on new session variables belonging to role %s"),
+ rolename);
+ break;
default:
/* shouldn't get here */
if (nspname)
@@ -4670,6 +4752,10 @@ getObjectTypeDescription(const ObjectAddress *object, bool missing_ok)
appendStringInfoString(&buffer, "transform");
break;
+ case VariableRelationId:
+ appendStringInfoString(&buffer, "session variable");
+ break;
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
@@ -5780,6 +5866,10 @@ getObjectIdentityParts(const ObjectAddress *object,
appendStringInfoString(&buffer,
" on large objects");
break;
+ case DEFACLOBJ_VARIABLE:
+ appendStringInfoString(&buffer,
+ " on session variables");
+ break;
}
if (objname)
@@ -6020,6 +6110,33 @@ getObjectIdentityParts(const ObjectAddress *object,
}
break;
+ case VariableRelationId:
+ {
+ char *schema;
+ char *varname;
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(object->objectId));
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u",
+ object->objectId);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ schema = get_namespace_name_or_temp(varform->varnamespace);
+ varname = NameStr(varform->varname);
+
+ appendStringInfo(&buffer, "%s",
+ quote_qualified_identifier(schema, varname));
+
+ if (objname)
+ *objname = list_make2(schema, pstrdup(varname));
+
+ ReleaseSysCache(tup);
+ break;
+ }
+
default:
elog(ERROR, "unsupported object class: %u", object->classId);
}
diff --git a/src/backend/catalog/pg_shdepend.c b/src/backend/catalog/pg_shdepend.c
index 536191284e8..c6fd1fa074f 100644
--- a/src/backend/catalog/pg_shdepend.c
+++ b/src/backend/catalog/pg_shdepend.c
@@ -46,6 +46,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_type.h"
#include "catalog/pg_user_mapping.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
@@ -1714,6 +1715,7 @@ shdepReassignOwned_Owner(Form_pg_shdepend sdepForm, Oid newrole)
case DatabaseRelationId:
case TSConfigRelationId:
case TSDictionaryRelationId:
+ case VariableRelationId:
AlterObjectOwner_internal(sdepForm->classid,
sdepForm->objid,
newrole);
diff --git a/src/backend/catalog/pg_variable.c b/src/backend/catalog/pg_variable.c
new file mode 100644
index 00000000000..29d967a2d5b
--- /dev/null
+++ b/src/backend/catalog/pg_variable.c
@@ -0,0 +1,251 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.c
+ * session variables
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/catalog/pg_variable.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "catalog/dependency.h"
+#include "catalog/indexing.h"
+#include "catalog/namespace.h"
+#include "catalog/objectaccess.h"
+#include "catalog/pg_collation.h"
+#include "catalog/pg_namespace.h"
+#include "catalog/pg_variable.h"
+#include "miscadmin.h"
+#include "parser/parse_type.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+static ObjectAddress create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists);
+
+
+/*
+ * Creates entry in pg_variable table
+ */
+static ObjectAddress
+create_variable(const char *varName,
+ Oid varNamespace,
+ Oid varType,
+ int32 varTypmod,
+ Oid varOwner,
+ Oid varCollation,
+ bool if_not_exists)
+{
+ Acl *varacl;
+ NameData varname;
+ bool nulls[Natts_pg_variable];
+ Datum values[Natts_pg_variable];
+ Relation rel;
+ HeapTuple tup;
+ TupleDesc tupdesc;
+ ObjectAddress myself,
+ referenced;
+ ObjectAddresses *addrs;
+ Oid varid;
+
+ Assert(varName);
+ Assert(OidIsValid(varNamespace));
+ Assert(OidIsValid(varType));
+ Assert(OidIsValid(varOwner));
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ /*
+ * Check for duplicates. Note that this does not really prevent
+ * duplicates, it's here just to provide nicer error message in common
+ * case. The real protection is the unique key on the catalog.
+ */
+ if (SearchSysCacheExists2(VARIABLENAMENSP,
+ PointerGetDatum(varName),
+ ObjectIdGetDatum(varNamespace)))
+ {
+ if (if_not_exists)
+ ereport(NOTICE,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists, skipping",
+ varName)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_DUPLICATE_OBJECT),
+ errmsg("session variable \"%s\" already exists",
+ varName)));
+
+ table_close(rel, RowExclusiveLock);
+
+ return InvalidObjectAddress;
+ }
+
+ memset(values, 0, sizeof(values));
+ memset(nulls, false, sizeof(nulls));
+
+ namestrcpy(&varname, varName);
+
+ varid = GetNewOidWithIndex(rel, VariableOidIndexId, Anum_pg_variable_oid);
+
+ values[Anum_pg_variable_oid - 1] = ObjectIdGetDatum(varid);
+ values[Anum_pg_variable_varname - 1] = NameGetDatum(&varname);
+ values[Anum_pg_variable_varnamespace - 1] = ObjectIdGetDatum(varNamespace);
+ values[Anum_pg_variable_vartype - 1] = ObjectIdGetDatum(varType);
+ values[Anum_pg_variable_vartypmod - 1] = Int32GetDatum(varTypmod);
+ values[Anum_pg_variable_varowner - 1] = ObjectIdGetDatum(varOwner);
+ values[Anum_pg_variable_varcollation - 1] = ObjectIdGetDatum(varCollation);
+
+ varacl = get_user_default_acl(OBJECT_VARIABLE, varOwner,
+ varNamespace);
+ if (varacl != NULL)
+ values[Anum_pg_variable_varacl - 1] = PointerGetDatum(varacl);
+ else
+ nulls[Anum_pg_variable_varacl - 1] = true;
+
+ tupdesc = RelationGetDescr(rel);
+
+ tup = heap_form_tuple(tupdesc, values, nulls);
+ CatalogTupleInsert(rel, tup);
+ Assert(OidIsValid(varid));
+
+ addrs = new_object_addresses();
+
+ ObjectAddressSet(myself, VariableRelationId, varid);
+
+ /* dependency on namespace */
+ ObjectAddressSet(referenced, NamespaceRelationId, varNamespace);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on used type */
+ ObjectAddressSet(referenced, TypeRelationId, varType);
+ add_exact_object_address(&referenced, addrs);
+
+ /* dependency on collation */
+ if (OidIsValid(varCollation) &&
+ varCollation != DEFAULT_COLLATION_OID)
+ {
+ ObjectAddressSet(referenced, CollationRelationId, varCollation);
+ add_exact_object_address(&referenced, addrs);
+ }
+
+ record_object_address_dependencies(&myself, addrs, DEPENDENCY_NORMAL);
+ free_object_addresses(addrs);
+
+ /* dependency on owner */
+ recordDependencyOnOwner(VariableRelationId, varid, varOwner);
+
+ /* dependencies on roles mentioned in default ACL */
+ recordDependencyOnNewAcl(VariableRelationId, varid, 0, varOwner, varacl);
+
+ /* dependency on extension */
+ recordDependencyOnCurrentExtension(&myself, false);
+
+ heap_freetuple(tup);
+
+ /* post creation hook for new function */
+ InvokeObjectPostCreateHook(VariableRelationId, varid, 0);
+
+ table_close(rel, RowExclusiveLock);
+
+ return myself;
+}
+
+/*
+ * Creates a new variable
+ *
+ * Used by CREATE VARIABLE command
+ */
+ObjectAddress
+CreateVariable(ParseState *pstate, CreateSessionVarStmt *stmt)
+{
+ Oid namespaceid;
+ AclResult aclresult;
+ Oid typid;
+ int32 typmod;
+ Oid varowner = GetUserId();
+ Oid collation;
+ Oid typcollation;
+ ObjectAddress variable;
+
+ namespaceid =
+ RangeVarGetAndCheckCreationNamespace(stmt->variable, NoLock, NULL);
+
+ typenameTypeIdAndMod(pstate, stmt->typeName, &typid, &typmod);
+
+ /* disallow pseudotypes */
+ if (get_typtype(typid) == TYPTYPE_PSEUDO)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("session variable cannot be pseudo-type %s",
+ format_type_be(typid))));
+
+ aclresult = object_aclcheck(TypeRelationId, typid, GetUserId(), ACL_USAGE);
+ if (aclresult != ACLCHECK_OK)
+ aclcheck_error_type(aclresult, typid);
+
+ typcollation = get_typcollation(typid);
+
+ if (stmt->collClause)
+ collation = LookupCollation(pstate,
+ stmt->collClause->collname,
+ stmt->collClause->location);
+ else
+ collation = typcollation;
+
+ /* complain if COLLATE is applied to an uncollatable type */
+ if (OidIsValid(collation) && !OidIsValid(typcollation))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("collations are not supported by type %s",
+ format_type_be(typid)),
+ parser_errposition(pstate, stmt->collClause->location)));
+
+ variable = create_variable(stmt->variable->relname,
+ namespaceid,
+ typid,
+ typmod,
+ varowner,
+ collation,
+ stmt->if_not_exists);
+
+ elog(DEBUG1, "record for session variable \"%s\" (oid:%d) was created in pg_variable",
+ stmt->variable->relname, variable.objectId);
+
+ return variable;
+}
+
+/*
+ * Drop variable by OID
+ */
+void
+DropVariableById(Oid varid)
+{
+ Relation rel;
+ HeapTuple tup;
+
+ rel = table_open(VariableRelationId, RowExclusiveLock);
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ CatalogTupleDelete(rel, &tup->t_self);
+
+ ReleaseSysCache(tup);
+
+ table_close(rel, RowExclusiveLock);
+}
diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index c801c869c1c..c72a4adb07b 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -41,6 +41,7 @@
#include "catalog/pg_ts_dict.h"
#include "catalog/pg_ts_parser.h"
#include "catalog/pg_ts_template.h"
+#include "catalog/pg_variable.h"
#include "commands/alter.h"
#include "commands/collationcmds.h"
#include "commands/dbcommands.h"
@@ -140,6 +141,10 @@ report_namespace_conflict(Oid classId, const char *name, Oid nspOid)
Assert(OidIsValid(nspOid));
msgfmt = gettext_noop("text search configuration \"%s\" already exists in schema \"%s\"");
break;
+ case VariableRelationId:
+ Assert(OidIsValid(nspOid));
+ msgfmt = gettext_noop("session variable \"%s\" already exists in schema \"%s\"");
+ break;
default:
elog(ERROR, "unsupported object class: %u", classId);
break;
@@ -435,6 +440,7 @@ ExecRenameStmt(RenameStmt *stmt)
case OBJECT_TSTEMPLATE:
case OBJECT_PUBLICATION:
case OBJECT_SUBSCRIPTION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
Relation catalog;
@@ -575,6 +581,7 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt,
case OBJECT_TSDICTIONARY:
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
+ case OBJECT_VARIABLE:
{
Relation catalog;
Oid classId;
@@ -657,6 +664,7 @@ AlterObjectNamespace_oid(Oid classId, Oid objid, Oid nspOid,
case TSDictionaryRelationId:
case TSTemplateRelationId:
case TSConfigRelationId:
+ case VariableRelationId:
{
Relation catalog;
@@ -887,6 +895,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
case OBJECT_TABLESPACE:
case OBJECT_TSDICTIONARY:
case OBJECT_TSCONFIGURATION:
+ case OBJECT_VARIABLE:
{
ObjectAddress address;
diff --git a/src/backend/commands/dropcmds.c b/src/backend/commands/dropcmds.c
index ceb9a229b63..ebb585dc4a1 100644
--- a/src/backend/commands/dropcmds.c
+++ b/src/backend/commands/dropcmds.c
@@ -476,6 +476,10 @@ does_not_exist_skipping(ObjectType objtype, Node *object)
msg = gettext_noop("publication \"%s\" does not exist, skipping");
name = strVal(object);
break;
+ case OBJECT_VARIABLE:
+ msg = gettext_noop("session variable \"%s\" does not exist, skipping");
+ name = NameListToString(castNode(List, object));
+ break;
case OBJECT_COLUMN:
case OBJECT_DATABASE:
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index edc2c988e29..1839c1f82c5 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -2149,6 +2149,8 @@ stringify_grant_objtype(ObjectType objtype)
return "TABLESPACE";
case OBJECT_TYPE:
return "TYPE";
+ case OBJECT_VARIABLE:
+ return "VARIABLE";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
@@ -2232,6 +2234,8 @@ stringify_adefprivs_objtype(ObjectType objtype)
return "TABLESPACES";
case OBJECT_TYPE:
return "TYPES";
+ case OBJECT_VARIABLE:
+ return "VARIABLES";
/* these currently aren't used */
case OBJECT_ACCESS_METHOD:
case OBJECT_AGGREGATE:
diff --git a/src/backend/commands/seclabel.c b/src/backend/commands/seclabel.c
index cee5d7bbb9c..57b4e6719c2 100644
--- a/src/backend/commands/seclabel.c
+++ b/src/backend/commands/seclabel.c
@@ -92,6 +92,7 @@ SecLabelSupportsObjectType(ObjectType objtype)
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
case OBJECT_USER_MAPPING:
+ case OBJECT_VARIABLE:
return false;
/*
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 54ad38247aa..0cc06c1e67b 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -52,6 +52,7 @@
#include "catalog/pg_tablespace.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "catalog/storage.h"
#include "catalog/storage_xlog.h"
#include "catalog/toasting.h"
@@ -6910,6 +6911,7 @@ ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
* (possibly nested several levels deep in composite types, arrays, etc!).
* Eventually, we'd like to propagate the check or rewrite operation
* into such tables, but for now, just error out if we find any.
+ * Also, check if "typeOid" is used as type of some session variable.
*
* Caller should provide either the associated relation of a rowtype,
* or a type name (not both) for use in the error message, if any.
@@ -6973,6 +6975,45 @@ find_composite_type_dependencies(Oid typeOid, Relation origRelation,
continue;
}
+ /* check if the type is used as type of some session variable */
+ if (pg_depend->classid == VariableRelationId)
+ {
+ Oid varid = pg_depend->objid;
+
+ if (origTypeName)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ origTypeName,
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter type \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter foreign table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+ else if (origRelation->rd_rel->relkind == RELKIND_RELATION ||
+ origRelation->rd_rel->relkind == RELKIND_MATVIEW ||
+ origRelation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter table \"%s\" because session variable \"%s.%s\" uses it",
+ RelationGetRelationName(origRelation),
+ get_namespace_name(get_session_variable_namespace(varid)),
+ get_session_variable_name(varid))));
+
+ continue;
+ }
+
/* Else, ignore dependees that aren't relations */
if (pg_depend->classid != RelationRelationId)
continue;
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 45ae7472ab5..f8fefdc2cf8 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -53,6 +53,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_range.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/tablecmds.h"
#include "commands/typecmds.h"
@@ -3373,6 +3374,20 @@ get_rels_with_domain(Oid domainOid, LOCKMODE lockmode)
}
continue;
}
+ else if (pg_depend->classid == VariableRelationId)
+ {
+ /*
+ * We cannot to validate constraint inside session variables
+ * from other sessions, so better to fail if there are any
+ * session variable, that use this domain.
+ */
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot alter domain \"%s\" because session variable \"%s.%s\" uses it",
+ domainTypeName,
+ get_namespace_name(get_session_variable_namespace(pg_depend->objid)),
+ get_session_variable_name(pg_depend->objid))));
+ }
/* Else, ignore dependees that aren't user columns of relations */
/* (we assume system columns are never of domain types) */
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 3c4268b271a..71c71272958 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -52,6 +52,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_am.h"
#include "catalog/pg_trigger.h"
+#include "catalog/pg_variable.h"
#include "commands/defrem.h"
#include "commands/trigger.h"
#include "gramparse.h"
@@ -285,8 +286,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
ConstraintsSetStmt CopyStmt CreateAsStmt CreateCastStmt
CreateDomainStmt CreateExtensionStmt CreateGroupStmt CreateOpClassStmt
CreateOpFamilyStmt AlterOpFamilyStmt CreatePLangStmt
- CreateSchemaStmt CreateSeqStmt CreateStmt CreateStatsStmt CreateTableSpaceStmt
- CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
+ CreateSchemaStmt CreateSeqStmt CreateSessionVarStmt CreateStmt CreateStatsStmt
+ CreateTableSpaceStmt CreateFdwStmt CreateForeignServerStmt CreateForeignTableStmt
CreateAssertionStmt CreateTransformStmt CreateTrigStmt CreateEventTrigStmt
CreateUserStmt CreateUserMappingStmt CreateRoleStmt CreatePolicyStmt
CreatedbStmt DeclareCursorStmt DefineStmt DeleteStmt DiscardStmt DoStmt
@@ -783,8 +784,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
UESCAPE UNBOUNDED UNCONDITIONAL UNCOMMITTED UNENCRYPTED UNION UNIQUE UNKNOWN
UNLISTEN UNLOGGED UNTIL UPDATE USER USING
- VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARYING
- VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
+ VACUUM VALID VALIDATE VALIDATOR VALUE_P VALUES VARCHAR VARIADIC VARIABLE
+ VARIABLES VARYING VERBOSE VERSION_P VIEW VIEWS VIRTUAL VOLATILE
WHEN WHERE WHITESPACE_P WINDOW WITH WITHIN WITHOUT WORK WRAPPER WRITE
@@ -1050,6 +1051,7 @@ stmt:
| CreatePolicyStmt
| CreatePLangStmt
| CreateSchemaStmt
+ | CreateSessionVarStmt
| CreateSeqStmt
| CreateStmt
| CreateSubscriptionStmt
@@ -1592,6 +1594,7 @@ schema_stmt:
| CreateTrigStmt
| GrantStmt
| ViewStmt
+ | CreateSessionVarStmt
;
@@ -5267,6 +5270,34 @@ create_extension_opt_item:
}
;
+/*****************************************************************************
+ *
+ * QUERY :
+ * CREATE VARIABLE varname [AS] type
+ *
+ *****************************************************************************/
+
+CreateSessionVarStmt:
+ CREATE VARIABLE qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $3;
+ n->typeName = $5;
+ n->collClause = (CollateClause *) $6;
+ n->if_not_exists = false;
+ $$ = (Node *) n;
+ }
+ | CREATE VARIABLE IF_P NOT EXISTS qualified_name opt_as Typename opt_collate_clause
+ {
+ CreateSessionVarStmt *n = makeNode(CreateSessionVarStmt);
+ n->variable = $6;
+ n->typeName = $8;
+ n->collClause = (CollateClause *) $9;
+ n->if_not_exists = true;
+ $$ = (Node *) n;
+ }
+ ;
+
/*****************************************************************************
*
* ALTER EXTENSION name UPDATE [ TO version ]
@@ -7058,6 +7089,7 @@ object_type_any_name:
| TEXT_P SEARCH DICTIONARY { $$ = OBJECT_TSDICTIONARY; }
| TEXT_P SEARCH TEMPLATE { $$ = OBJECT_TSTEMPLATE; }
| TEXT_P SEARCH CONFIGURATION { $$ = OBJECT_TSCONFIGURATION; }
+ | VARIABLE { $$ = OBJECT_VARIABLE; }
;
/*
@@ -7934,6 +7966,14 @@ privilege_target:
n->objs = $2;
$$ = n;
}
+ | VARIABLE qualified_name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_OBJECT;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $2;
+ $$ = n;
+ }
| ALL TABLES IN_P SCHEMA name_list
{
PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
@@ -7979,6 +8019,14 @@ privilege_target:
n->objs = $5;
$$ = n;
}
+ | ALL VARIABLES IN_P SCHEMA name_list
+ {
+ PrivTarget *n = (PrivTarget *) palloc(sizeof(PrivTarget));
+ n->targtype = ACL_TARGET_ALL_IN_SCHEMA;
+ n->objtype = OBJECT_VARIABLE;
+ n->objs = $5;
+ $$ = n;
+ }
;
@@ -8177,6 +8225,7 @@ defacl_privilege_target:
| TYPES_P { $$ = OBJECT_TYPE; }
| SCHEMAS { $$ = OBJECT_SCHEMA; }
| LARGE_P OBJECTS_P { $$ = OBJECT_LARGEOBJECT; }
+ | VARIABLES { $$ = OBJECT_VARIABLE; }
;
@@ -9965,6 +10014,24 @@ RenameStmt: ALTER AGGREGATE aggregate_with_argtypes RENAME TO name
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newname = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name RENAME TO name
+ {
+ RenameStmt *n = makeNode(RenameStmt);
+ n->renameType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newname = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
opt_column: COLUMN
@@ -10326,6 +10393,24 @@ AlterObjectSchemaStmt:
n->missing_ok = false;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newschema = $6;
+ n->missing_ok = false;
+ $$ = (Node *)n;
+ }
+ | ALTER VARIABLE IF_P EXISTS any_name SET SCHEMA name
+ {
+ AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $5;
+ n->newschema = $8;
+ n->missing_ok = true;
+ $$ = (Node *)n;
+ }
;
/*****************************************************************************
@@ -10607,6 +10692,14 @@ AlterOwnerStmt: ALTER AGGREGATE aggregate_with_argtypes OWNER TO RoleSpec
n->newowner = $6;
$$ = (Node *) n;
}
+ | ALTER VARIABLE any_name OWNER TO RoleSpec
+ {
+ AlterOwnerStmt *n = makeNode(AlterOwnerStmt);
+ n->objectType = OBJECT_VARIABLE;
+ n->object = (Node *) $3;
+ n->newowner = $6;
+ $$ = (Node *)n;
+ }
;
@@ -18017,6 +18110,8 @@ unreserved_keyword:
| VALIDATE
| VALIDATOR
| VALUE_P
+ | VARIABLE
+ | VARIABLES
| VARYING
| VERSION_P
| VIEW
@@ -18673,6 +18768,8 @@ bare_label_keyword:
| VALUE_P
| VALUES
| VARCHAR
+ | VARIABLE
+ | VARIABLES
| VARIADIC
| VERBOSE
| VERSION_P
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index 62015431fdf..b6cbe354c51 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -105,6 +105,7 @@ typedef struct
List *indexes; /* CREATE INDEX items */
List *triggers; /* CREATE TRIGGER items */
List *grants; /* GRANT items */
+ List *variables; /* CREATE VARIABLE items */
} CreateSchemaStmtContext;
@@ -4091,6 +4092,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.indexes = NIL;
cxt.triggers = NIL;
cxt.grants = NIL;
+ cxt.variables = NIL;
/*
* Run through each schema element in the schema element list. Separate
@@ -4159,6 +4161,15 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
cxt.grants = lappend(cxt.grants, element);
break;
+ case T_CreateSessionVarStmt:
+ {
+ CreateSessionVarStmt *elp = (CreateSessionVarStmt *) element;
+
+ setSchemaName(cxt.schemaname, &elp->variable->schemaname);
+ cxt.variables = lappend(cxt.variables, element);
+ }
+ break;
+
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(element));
@@ -4172,6 +4183,7 @@ transformCreateSchemaStmtElements(List *schemaElts, const char *schemaName)
result = list_concat(result, cxt.indexes);
result = list_concat(result, cxt.triggers);
result = list_concat(result, cxt.grants);
+ result = list_concat(result, cxt.variables);
return result;
}
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 25fe3d58016..99a51877d34 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -23,6 +23,7 @@
#include "catalog/namespace.h"
#include "catalog/pg_authid.h"
#include "catalog/pg_inherits.h"
+#include "catalog/pg_variable.h"
#include "catalog/toasting.h"
#include "commands/alter.h"
#include "commands/async.h"
@@ -182,6 +183,7 @@ ClassifyUtilityCommandAsReadOnly(Node *parsetree)
case T_CreateRangeStmt:
case T_CreateRoleStmt:
case T_CreateSchemaStmt:
+ case T_CreateSessionVarStmt:
case T_CreateSeqStmt:
case T_CreateStatsStmt:
case T_CreateStmt:
@@ -1389,6 +1391,10 @@ ProcessUtilitySlow(ParseState *pstate,
}
break;
+ case T_CreateSessionVarStmt:
+ address = CreateVariable(pstate, (CreateSessionVarStmt *) parsetree);
+ break;
+
/*
* ************* object creation / destruction **************
*/
@@ -2341,6 +2347,9 @@ AlterObjectTypeCommandTag(ObjectType objtype)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_ALTER_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_ALTER_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
break;
@@ -2649,6 +2658,9 @@ CreateCommandTag(Node *parsetree)
case OBJECT_STATISTIC_EXT:
tag = CMDTAG_DROP_STATISTICS;
break;
+ case OBJECT_VARIABLE:
+ tag = CMDTAG_DROP_VARIABLE;
+ break;
default:
tag = CMDTAG_UNKNOWN;
}
@@ -3225,6 +3237,10 @@ CreateCommandTag(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ tag = CMDTAG_CREATE_VARIABLE;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
@@ -3759,6 +3775,10 @@ GetCommandLogLevel(Node *parsetree)
}
break;
+ case T_CreateSessionVarStmt:
+ lev = LOGSTMT_DDL;
+ break;
+
default:
elog(WARNING, "unrecognized node type: %d",
(int) nodeTag(parsetree));
diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index ca3c5ee3df3..07874d4ba39 100644
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -31,6 +31,7 @@
#include "catalog/pg_proc.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "commands/dbcommands.h"
#include "commands/proclang.h"
#include "commands/tablespace.h"
@@ -129,6 +130,8 @@ static AclMode convert_type_priv_string(text *priv_type_text);
static AclMode convert_parameter_priv_string(text *priv_text);
static AclMode convert_largeobject_priv_string(text *priv_type_text);
static AclMode convert_role_priv_string(text *priv_type_text);
+static Oid convert_session_variable_name(text *varname);
+static AclMode convert_session_variable_priv_string(text *priv_type_text);
static AclResult pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode);
static void RoleMembershipCacheCallback(Datum arg, int cacheid, uint32 hashvalue);
@@ -851,6 +854,10 @@ acldefault(ObjectType objtype, Oid ownerId)
world_default = ACL_NO_RIGHTS;
owner_default = ACL_ALL_RIGHTS_PARAMETER_ACL;
break;
+ case OBJECT_VARIABLE:
+ world_default = ACL_NO_RIGHTS;
+ owner_default = ACL_ALL_RIGHTS_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type: %d", (int) objtype);
world_default = ACL_NO_RIGHTS; /* keep compiler quiet */
@@ -948,6 +955,9 @@ acldefault_sql(PG_FUNCTION_ARGS)
case 'T':
objtype = OBJECT_TYPE;
break;
+ case 'V':
+ objtype = OBJECT_VARIABLE;
+ break;
default:
elog(ERROR, "unrecognized object type abbreviation: %c", objtypec);
}
@@ -5016,6 +5026,217 @@ pg_role_aclcheck(Oid role_oid, Oid roleid, AclMode mode)
return ACLCHECK_NO_PRIV;
}
+/*
+ * has_session_variable_privilege variants
+ * These are all named "has_session_variable_privilege" at the SQL level.
+ * They take various combinations of variable name, variable OID,
+ * user name, user OID, or implicit user = current_user.
+ *
+ * The result is a boolean value: true if user has the indicated
+ * privilege, false if not, or NULL if session variable doesn't
+ * exists.
+ */
+
+/*
+ * has_session_variable_privilege_name_name
+ * Check user privileges on a session variable given
+ * name username, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_name(PG_FUNCTION_ARGS)
+{
+ Name rolename = PG_GETARG_NAME(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*rolename));
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name
+ * Check user privileges on a session variable given
+ * text session variable and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_name(PG_FUNCTION_ARGS)
+{
+ text *varname = PG_GETARG_TEXT_PP(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_name_id
+ * Check user privileges on a session variable given
+ * name usename, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_name_id(PG_FUNCTION_ARGS)
+{
+ Name username = PG_GETARG_NAME(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = get_role_oid_or_public(NameStr(*username));
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id
+ * Check user privileges on a session variable given
+ * session variable oid, and text priv name.
+ * current_user is assumed
+ */
+Datum
+has_session_variable_privilege_id(PG_FUNCTION_ARGS)
+{
+ Oid varid = PG_GETARG_OID(0);
+ text *priv_type_text = PG_GETARG_TEXT_PP(1);
+ Oid roleid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ roleid = GetUserId();
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_name
+ * Check user privileges on a session variable given
+ * roleid, text session variable name, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_name(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ text *varname = PG_GETARG_TEXT_PP(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ Oid varid;
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+ varid = convert_session_variable_name(varname);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * has_session_variable_privilege_id_id
+ * Check user privileges on a session variable given
+ * roleid, session variable oid, and text priv name.
+ */
+Datum
+has_session_variable_privilege_id_id(PG_FUNCTION_ARGS)
+{
+ Oid roleid = PG_GETARG_OID(0);
+ Oid varid = PG_GETARG_OID(1);
+ text *priv_type_text = PG_GETARG_TEXT_PP(2);
+ AclMode mode;
+ AclResult aclresult;
+ bool is_missing = false;
+
+ mode = convert_session_variable_priv_string(priv_type_text);
+
+ aclresult = object_aclcheck_ext(VariableRelationId, varid,
+ roleid, mode,
+ &is_missing);
+
+ if (is_missing)
+ PG_RETURN_NULL();
+
+ PG_RETURN_BOOL(aclresult == ACLCHECK_OK);
+}
+
+/*
+ * Given a session variable name expressed as a string, look it up and return
+ * Oid
+ */
+static Oid
+convert_session_variable_name(text *varname)
+{
+ return LookupVariableFromNameList(textToQualifiedNameList(varname), true);
+}
+
+/*
+ * convert_variable_priv_string
+ * Convert text string to AclMode value.
+ */
+static AclMode
+convert_session_variable_priv_string(text *priv_type_text)
+{
+ static const priv_map session_variable_priv_map[] = {
+ {"SELECT", ACL_SELECT},
+ {"SELECT WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_SELECT)},
+ {"UPDATE", ACL_UPDATE},
+ {"UPDATE WITH GRANT OPTION", ACL_GRANT_OPTION_FOR(ACL_UPDATE)},
+ {NULL, 0}
+ };
+
+ return convert_any_priv_string(priv_type_text, session_variable_priv_map);
+}
/*
* initialization function (called by InitPostgres)
diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index c460a72b75d..d77121b63f8 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -39,6 +39,7 @@
#include "catalog/pg_subscription.h"
#include "catalog/pg_transform.h"
#include "catalog/pg_type.h"
+#include "catalog/pg_variable.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "utils/array.h"
@@ -3854,3 +3855,115 @@ get_subscription_name(Oid subid, bool missing_ok)
return subname;
}
+
+/* ---------- PG_VARIABLE CACHE ---------- */
+
+/*
+ * get_varname_varid
+ * Given name and namespace of variable, look up the OID.
+ */
+Oid
+get_varname_varid(const char *varname, Oid varnamespace)
+{
+ return GetSysCacheOid2(VARIABLENAMENSP, Anum_pg_variable_oid,
+ PointerGetDatum(varname),
+ ObjectIdGetDatum(varnamespace));
+}
+
+/*
+ * get_session_variable_name
+ * Returns a palloc'd copy of the name of a given session variable.
+ */
+char *
+get_session_variable_name(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ char *varname;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varname = pstrdup(NameStr(varform->varname));
+
+ ReleaseSysCache(tup);
+
+ return varname;
+}
+
+/*
+ * get_session_variable_namespace
+ * Returns the pg_namespace OID associated with a given session variable.
+ */
+Oid
+get_session_variable_namespace(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid varnamespace;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ varnamespace = varform->varnamespace;
+
+ ReleaseSysCache(tup);
+
+ return varnamespace;
+}
+
+/*
+ * Returns the type of the given session variable.
+ */
+Oid
+get_session_variable_type(Oid varid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+ Oid vartype;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ vartype = varform->vartype;
+
+ ReleaseSysCache(tup);
+
+ return vartype;
+}
+
+/*
+ * Returns the type, typmod and collid of the given session variable.
+ */
+void
+get_session_variable_type_typmod_collid(Oid varid, Oid *typid, int32 *typmod,
+ Oid *collid)
+{
+ HeapTuple tup;
+ Form_pg_variable varform;
+
+ tup = SearchSysCache1(VARIABLEOID, ObjectIdGetDatum(varid));
+
+ if (!HeapTupleIsValid(tup))
+ elog(ERROR, "cache lookup failed for session variable %u", varid);
+
+ varform = (Form_pg_variable) GETSTRUCT(tup);
+
+ *typid = varform->vartype;
+ *typmod = varform->vartypmod;
+ *collid = varform->varcollation;
+
+ ReleaseSysCache(tup);
+}
diff --git a/src/bin/pg_dump/common.c b/src/bin/pg_dump/common.c
index aa1589e3331..86360bd6d95 100644
--- a/src/bin/pg_dump/common.c
+++ b/src/bin/pg_dump/common.c
@@ -246,6 +246,9 @@ getSchemaData(Archive *fout, int *numTablesPtr)
pg_log_info("reading subscription membership of tables");
getSubscriptionTables(fout);
+ pg_log_info("reading variables");
+ getVariables(fout);
+
free(inhinfo); /* not needed any longer */
*numTablesPtr = numTables;
diff --git a/src/bin/pg_dump/dumputils.c b/src/bin/pg_dump/dumputils.c
index 73ce34346b2..cbca7c343a1 100644
--- a/src/bin/pg_dump/dumputils.c
+++ b/src/bin/pg_dump/dumputils.c
@@ -514,6 +514,12 @@ do { \
CONVERT_PRIV('r', "SELECT");
CONVERT_PRIV('w', "UPDATE");
}
+ else if (strcmp(type, "VARIABLE") == 0 ||
+ strcmp(type, "VARIABLES") == 0)
+ {
+ CONVERT_PRIV('r', "SELECT");
+ CONVERT_PRIV('w', "UPDATE");
+ }
else
abort();
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index af0007fb6d2..76356524af2 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -134,12 +134,14 @@ typedef struct _restoreOptions
int selFunction;
int selTrigger;
int selTable;
+ int selVariable;
SimpleStringList indexNames;
SimpleStringList functionNames;
SimpleStringList schemaNames;
SimpleStringList schemaExcludeNames;
SimpleStringList triggerNames;
SimpleStringList tableNames;
+ SimpleStringList variableNames;
int useDB;
ConnParams cparams; /* parameters to use if useDB */
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index afa42337b11..e7964131c2e 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -3179,6 +3179,14 @@ _tocEntryRequired(TocEntry *te, teSection curSection, ArchiveHandle *AH)
!simple_string_list_member(&ropt->triggerNames, te->tag))
return 0;
}
+ else if (strcmp(te->desc, "VARIABLE") == 0)
+ {
+ if (!ropt->selVariable)
+ return 0;
+ if (ropt->variableNames.head != NULL &&
+ !simple_string_list_member(&ropt->variableNames, te->tag))
+ return 0;
+ }
else
return 0;
}
@@ -3742,6 +3750,7 @@ _getObjectDescription(PQExpBuffer buf, const TocEntry *te)
strcmp(type, "TEXT SEARCH DICTIONARY") == 0 ||
strcmp(type, "TEXT SEARCH CONFIGURATION") == 0 ||
strcmp(type, "TYPE") == 0 ||
+ strcmp(type, "VARIABLE") == 0 ||
strcmp(type, "VIEW") == 0 ||
/* non-schema-specified objects */
strcmp(type, "DATABASE") == 0 ||
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index e2e7975b34e..255800eca11 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -370,6 +370,7 @@ static void dumpPublication(Archive *fout, const PublicationInfo *pubinfo);
static void dumpPublicationTable(Archive *fout, const PublicationRelInfo *pubrinfo);
static void dumpSubscription(Archive *fout, const SubscriptionInfo *subinfo);
static void dumpSubscriptionTable(Archive *fout, const SubRelInfo *subrinfo);
+static void dumpVariable(Archive *fout, const VariableInfo *varinfo);
static void dumpDatabase(Archive *fout);
static void dumpDatabaseConfig(Archive *AH, PQExpBuffer outbuf,
const char *dbname, Oid dboid);
@@ -5512,6 +5513,188 @@ get_next_possible_free_pg_type_oid(Archive *fout, PQExpBuffer upgrade_query)
return next_possible_free_oid;
}
+/*
+ * getVariables
+ * get information about variables
+ */
+void
+getVariables(Archive *fout)
+{
+ PQExpBuffer query;
+ PGresult *res;
+ VariableInfo *varinfo;
+ int i_tableoid;
+ int i_oid;
+ int i_varname;
+ int i_varnamespace;
+ int i_vartype;
+ int i_vartypname;
+ int i_varowner;
+ int i_varcollation;
+ int i_varacl;
+ int i_acldefault;
+ int i,
+ ntups;
+
+ if (fout->remoteVersion < 180000)
+ return;
+
+ query = createPQExpBuffer();
+
+ /* get the variables in current database */
+ appendPQExpBuffer(query,
+ "SELECT v.tableoid, v.oid, v.varname,\n"
+ " v.varnamespace, v.vartype,\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as vartypname,\n"
+ " CASE WHEN v.varcollation <> t.typcollation "
+ " THEN v.varcollation\n"
+ " ELSE 0\n"
+ " END AS varcollation,\n"
+ " v.varowner, v.varacl,\n"
+ " acldefault('V', v.varowner) AS acldefault\n"
+ "FROM pg_catalog.pg_variable v\n"
+ "JOIN pg_catalog.pg_type t "
+ "ON (v.vartype = t.oid)");
+
+ res = ExecuteSqlQuery(fout, query->data, PGRES_TUPLES_OK);
+
+ ntups = PQntuples(res);
+
+ i_tableoid = PQfnumber(res, "tableoid");
+ i_oid = PQfnumber(res, "oid");
+ i_varname = PQfnumber(res, "varname");
+ i_varnamespace = PQfnumber(res, "varnamespace");
+ i_vartype = PQfnumber(res, "vartype");
+ i_vartypname = PQfnumber(res, "vartypname");
+ i_varcollation = PQfnumber(res, "varcollation");
+
+ i_varowner = PQfnumber(res, "varowner");
+ i_varacl = PQfnumber(res, "varacl");
+ i_acldefault = PQfnumber(res, "acldefault");
+
+ varinfo = pg_malloc(ntups * sizeof(VariableInfo));
+
+ for (i = 0; i < ntups; i++)
+ {
+ TypeInfo *vtype;
+
+ varinfo[i].dobj.objType = DO_VARIABLE;
+ varinfo[i].dobj.catId.tableoid =
+ atooid(PQgetvalue(res, i, i_tableoid));
+ varinfo[i].dobj.catId.oid = atooid(PQgetvalue(res, i, i_oid));
+ AssignDumpId(&varinfo[i].dobj);
+ varinfo[i].dobj.name = pg_strdup(PQgetvalue(res, i, i_varname));
+ varinfo[i].dobj.namespace =
+ findNamespace(atooid(PQgetvalue(res, i, i_varnamespace)));
+
+ varinfo[i].vartype = atooid(PQgetvalue(res, i, i_vartype));
+ varinfo[i].vartypname = pg_strdup(PQgetvalue(res, i, i_vartypname));
+ varinfo[i].varcollation = atooid(PQgetvalue(res, i, i_varcollation));
+
+ varinfo[i].dacl.acl = pg_strdup(PQgetvalue(res, i, i_varacl));
+ varinfo[i].dacl.acldefault = pg_strdup(PQgetvalue(res, i, i_acldefault));
+ varinfo[i].dacl.privtype = 0;
+ varinfo[i].dacl.initprivs = NULL;
+ varinfo[i].rolname = getRoleName(PQgetvalue(res, i, i_varowner));
+
+ /* do not try to dump ACL if no ACL exists */
+ if (!PQgetisnull(res, i, i_varacl))
+ varinfo[i].dobj.components |= DUMP_COMPONENT_ACL;
+
+ if (strlen(varinfo[i].rolname) == 0)
+ pg_log_warning("owner of variable \"%s\" appears to be invalid",
+ varinfo[i].dobj.name);
+
+ /* decide whether we want to dump it */
+ selectDumpableObject(&(varinfo[i].dobj), fout);
+
+ vtype = findTypeByOid(varinfo[i].vartype);
+ addObjectDependency(&varinfo[i].dobj, vtype->dobj.dumpId);
+ }
+ PQclear(res);
+
+ destroyPQExpBuffer(query);
+}
+
+/*
+ * dumpVariable
+ * dump the definition of the given session variable
+ */
+static void
+dumpVariable(Archive *fout, const VariableInfo *varinfo)
+{
+ DumpOptions *dopt = fout->dopt;
+
+ PQExpBuffer delq;
+ PQExpBuffer query;
+ char *qualvarname;
+ const char *vartypname;
+ Oid varcollation;
+
+ /* skip if not to be dumped */
+ if (!varinfo->dobj.dump || !dopt->dumpSchema)
+ return;
+
+ delq = createPQExpBuffer();
+ query = createPQExpBuffer();
+
+ qualvarname = pg_strdup(fmtQualifiedDumpable(varinfo));
+ vartypname = varinfo->vartypname;
+ varcollation = varinfo->varcollation;
+
+ appendPQExpBuffer(delq, "DROP VARIABLE %s;\n",
+ qualvarname);
+
+ appendPQExpBuffer(query, "CREATE VARIABLE %s AS %s",
+ qualvarname, vartypname);
+
+ if (OidIsValid(varcollation))
+ {
+ CollInfo *coll;
+
+ coll = findCollationByOid(varcollation);
+ if (coll)
+ appendPQExpBuffer(query, " COLLATE %s",
+ fmtQualifiedDumpable(coll));
+ }
+
+ appendPQExpBuffer(query, ";\n");
+
+ if (varinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
+ ArchiveEntry(fout, varinfo->dobj.catId, varinfo->dobj.dumpId,
+ ARCHIVE_OPTS(.tag = varinfo->dobj.name,
+ .namespace = varinfo->dobj.namespace->dobj.name,
+ .owner = varinfo->rolname,
+ .description = "VARIABLE",
+ .section = SECTION_PRE_DATA,
+ .createStmt = query->data,
+ .dropStmt = delq->data));
+
+ /* dump comment if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_COMMENT)
+ dumpComment(fout, "VARIABLE", qualvarname,
+ NULL, varinfo->rolname,
+ varinfo->dobj.catId, 0, varinfo->dobj.dumpId);
+
+ /* dump ACL if any */
+ if (varinfo->dobj.dump & DUMP_COMPONENT_ACL)
+ {
+ char *qvarname = pg_strdup(fmtId(varinfo->dobj.name));
+
+ dumpACL(fout, varinfo->dobj.dumpId, InvalidDumpId, "VARIABLE",
+ qvarname, NULL,
+ varinfo->dobj.namespace->dobj.name, NULL, varinfo->rolname,
+ &varinfo->dacl);
+
+ free(qvarname);
+ }
+
+ destroyPQExpBuffer(delq);
+ destroyPQExpBuffer(query);
+
+ free(qualvarname);
+}
+
static void
binary_upgrade_set_type_oids_by_type_oid(Archive *fout,
PQExpBuffer upgrade_buffer,
@@ -11540,6 +11723,9 @@ dumpDumpableObject(Archive *fout, DumpableObject *dobj)
case DO_REL_STATS:
dumpRelationStats(fout, (const RelStatsInfo *) dobj);
break;
+ case DO_VARIABLE:
+ dumpVariable(fout, (VariableInfo *) dobj);
+ break;
case DO_PRE_DATA_BOUNDARY:
case DO_POST_DATA_BOUNDARY:
/* never dumped, nothing to do */
@@ -15994,6 +16180,9 @@ dumpDefaultACL(Archive *fout, const DefaultACLInfo *daclinfo)
case DEFACLOBJ_LARGEOBJECT:
type = "LARGE OBJECTS";
break;
+ case DEFACLOBJ_VARIABLE:
+ type = "VARIABLES";
+ break;
default:
/* shouldn't get here */
pg_fatal("unrecognized object type in default privileges: %d",
@@ -19732,6 +19921,7 @@ addBoundaryDependencies(DumpableObject **dobjs, int numObjs,
case DO_CONVERSION:
case DO_TABLE:
case DO_TABLE_ATTACH:
+ case DO_VARIABLE:
case DO_ATTRDEF:
case DO_PROCLANG:
case DO_CAST:
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index 7417eab6aef..1c722e48de5 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -53,6 +53,7 @@ typedef enum
DO_TABLE,
DO_TABLE_ATTACH,
DO_ATTRDEF,
+ DO_VARIABLE,
DO_INDEX,
DO_INDEX_ATTACH,
DO_STATSEXT,
@@ -735,6 +736,19 @@ typedef struct _SubRelInfo
char *srsublsn;
} SubRelInfo;
+/*
+ * The VariableInfo struct is used to represent session variables
+ */
+typedef struct _VariableInfo
+{
+ DumpableObject dobj;
+ DumpableAcl dacl;
+ Oid vartype;
+ char *vartypname;
+ Oid varcollation;
+ const char *rolname; /* name of owner, or empty string */
+} VariableInfo;
+
/*
* common utility functions
*/
@@ -818,5 +832,6 @@ extern void getPublicationTables(Archive *fout, TableInfo tblinfo[],
int numTables);
extern void getSubscriptions(Archive *fout);
extern void getSubscriptionTables(Archive *fout);
+extern void getVariables(Archive *fout);
#endif /* PG_DUMP_H */
diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c
index 0b0977788f1..b34f3418f64 100644
--- a/src/bin/pg_dump/pg_dump_sort.c
+++ b/src/bin/pg_dump/pg_dump_sort.c
@@ -77,6 +77,7 @@ enum dbObjectTypePriorities
PRIO_DUMMY_TYPE,
PRIO_ATTRDEF,
PRIO_LARGE_OBJECT,
+ PRIO_VARIABLE,
PRIO_PRE_DATA_BOUNDARY, /* boundary! */
PRIO_TABLE_DATA,
PRIO_SEQUENCE_SET,
@@ -119,6 +120,7 @@ static const int dbObjectTypePriority[] =
[DO_TABLE] = PRIO_TABLE,
[DO_TABLE_ATTACH] = PRIO_TABLE_ATTACH,
[DO_ATTRDEF] = PRIO_ATTRDEF,
+ [DO_VARIABLE] = PRIO_VARIABLE,
[DO_INDEX] = PRIO_INDEX,
[DO_INDEX_ATTACH] = PRIO_INDEX_ATTACH,
[DO_STATSEXT] = PRIO_STATSEXT,
@@ -1533,6 +1535,11 @@ describeDumpableObject(DumpableObject *obj, char *buf, int bufsize)
"RELATION STATISTICS FOR %s (ID %d OID %u)",
obj->name, obj->dumpId, obj->catId.oid);
return;
+ case DO_VARIABLE:
+ snprintf(buf, bufsize,
+ "VARIABLE %s (ID %d OID %u)",
+ obj->name, obj->dumpId, obj->catId.oid);
+ return;
}
/* shouldn't get here */
snprintf(buf, bufsize,
diff --git a/src/bin/pg_dump/t/002_pg_dump.pl b/src/bin/pg_dump/t/002_pg_dump.pl
index 55d892d9c16..94eefb7c530 100644
--- a/src/bin/pg_dump/t/002_pg_dump.pl
+++ b/src/bin/pg_dump/t/002_pg_dump.pl
@@ -901,6 +901,16 @@ my %tests = (
unlike => { no_privs => 1, },
},
+ 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC'
+ => {
+ create_order => 56,
+ create_sql => 'ALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;',
+ regexp => qr/^
+ \QALTER DEFAULT PRIVILEGES FOR ROLE regress_dump_test_role GRANT SELECT ON VARIABLES TO PUBLIC;\E/xm,
+ like => { %full_runs, section_post_data => 1, },
+ unlike => { no_privs => 1, },
+ },
+
'ALTER ROLE regress_dump_test_role' => {
regexp => qr/^
\QALTER ROLE regress_dump_test_role WITH \E
@@ -1869,6 +1879,23 @@ my %tests = (
},
},
+ 'COMMENT ON VARIABLE dump_test.variable1' => {
+ create_order => 71,
+ create_sql => 'COMMENT ON VARIABLE dump_test.variable1
+ IS \'comment on variable\';',
+ regexp =>
+ qr/^\QCOMMENT ON VARIABLE dump_test.variable1 IS 'comment on variable';\E/m,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'COPY test_table' => {
create_order => 4,
create_sql => 'INSERT INTO dump_test.test_table (col1) '
@@ -4177,6 +4204,24 @@ my %tests = (
},
},
+ 'CREATE VARIABLE test_variable' => {
+ all_runs => 1,
+ catch_all => 'CREATE ... commands',
+ create_order => 61,
+ create_sql => 'CREATE VARIABLE dump_test.variable1 AS integer;',
+ regexp => qr/^
+ \QCREATE VARIABLE dump_test.variable1 AS integer;\E/xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'CREATE VIEW test_view' => {
create_order => 61,
create_sql => 'CREATE VIEW dump_test.test_view
@@ -4641,6 +4686,25 @@ my %tests = (
like => {},
},
+ 'GRANT SELECT ON VARIABLE dump_test.variable1' => {
+ create_order => 73,
+ create_sql =>
+ 'GRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;',
+ regexp => qr/^
+ \QGRANT SELECT ON VARIABLE dump_test.variable1 TO regress_dump_test_role;\E
+ /xm,
+ like => {
+ %full_runs,
+ %dump_test_schema_runs,
+ section_pre_data => 1,
+ },
+ unlike => {
+ exclude_dump_test_schema => 1,
+ no_privs => 1,
+ only_dump_measurement => 1,
+ },
+ },
+
'REFRESH MATERIALIZED VIEW matview' => {
regexp => qr/^\QREFRESH MATERIALIZED VIEW dump_test.matview;\E/m,
like =>
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 81a5ba844ba..a171bf5f3b4 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -1246,6 +1246,9 @@ exec_command_d(PsqlScanState scan_state, bool active_branch, const char *cmd)
break;
}
break;
+ case 'V': /* Variables */
+ success = listVariables(pattern, show_verbose);
+ break;
case 'x': /* Extensions */
if (show_verbose)
success = listExtensionContents(pattern);
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 1d08268393e..ad46ca4f9be 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -1223,7 +1223,7 @@ listDefaultACLs(const char *pattern)
"SELECT pg_catalog.pg_get_userbyid(d.defaclrole) AS \"%s\",\n"
" n.nspname AS \"%s\",\n"
" CASE d.defaclobjtype "
- " WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s'"
+ " WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s'"
" WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' WHEN '%c' THEN '%s' END AS \"%s\",\n"
" ",
gettext_noop("Owner"),
@@ -1240,6 +1240,8 @@ listDefaultACLs(const char *pattern)
gettext_noop("schema"),
DEFACLOBJ_LARGEOBJECT,
gettext_noop("large object"),
+ DEFACLOBJ_VARIABLE,
+ gettext_noop("session variable"),
gettext_noop("Type"));
printACLColumn(&buf, "d.defaclacl");
@@ -5313,6 +5315,102 @@ error_return:
return false;
}
+/*
+ * \dV
+ *
+ * listVariables()
+ */
+bool
+listVariables(const char *pattern, bool verbose)
+{
+ PQExpBufferData buf;
+ PGresult *res;
+ printQueryOpt myopt = pset.popt;
+ static const bool translate_columns[] = {false, false, false, false, false, false, false};
+
+ if (pset.sversion < 180000)
+ {
+ char sverbuf[32];
+
+ pg_log_error("The server (version %s) does not support session variables.",
+ formatPGVersionNumber(pset.sversion, false,
+ sverbuf, sizeof(sverbuf)));
+ return true;
+ }
+
+ initPQExpBuffer(&buf);
+
+ printfPQExpBuffer(&buf,
+ "SELECT n.nspname as \"%s\",\n"
+ " v.varname as \"%s\",\n"
+ " pg_catalog.format_type(v.vartype, v.vartypmod) as \"%s\",\n"
+ " (SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type bt\n"
+ " WHERE c.oid = v.varcollation AND bt.oid = v.vartype AND v.varcollation <> bt.typcollation) as \"%s\",\n"
+ " pg_catalog.pg_get_userbyid(v.varowner) as \"%s\"\n",
+ gettext_noop("Schema"),
+ gettext_noop("Name"),
+ gettext_noop("Type"),
+ gettext_noop("Collation"),
+ gettext_noop("Owner"));
+
+ if (verbose)
+ {
+ appendPQExpBufferStr(&buf, ",\n ");
+ printACLColumn(&buf, "v.varacl");
+ appendPQExpBuffer(&buf,
+ ",\n pg_catalog.obj_description(v.oid, 'pg_variable') AS \"%s\"",
+ gettext_noop("Description"));
+ }
+
+ appendPQExpBufferStr(&buf,
+ "\nFROM pg_catalog.pg_variable v"
+ "\n LEFT JOIN pg_catalog.pg_namespace n ON n.oid = v.varnamespace");
+
+ appendPQExpBufferStr(&buf, "\nWHERE true\n");
+ if (!pattern)
+ appendPQExpBufferStr(&buf, " AND n.nspname <> 'pg_catalog'\n"
+ " AND n.nspname <> 'information_schema'\n");
+
+ if (!validateSQLNamePattern(&buf, pattern, true, false,
+ "n.nspname", "v.varname", NULL,
+ "pg_catalog.pg_variable_is_visible(v.oid)",
+ NULL, 3))
+ return false;
+
+ appendPQExpBufferStr(&buf, "ORDER BY 1,2;");
+
+ res = PSQLexec(buf.data);
+ termPQExpBuffer(&buf);
+ if (!res)
+ return false;
+
+ /*
+ * Most functions in this file are content to print an empty table when
+ * there are no matching objects. We intentionally deviate from that
+ * here, but only in !quiet mode, for historical reasons.
+ */
+ if (PQntuples(res) == 0 && !pset.quiet)
+ {
+ if (pattern)
+ pg_log_error("Did not find any session variable named \"%s\".",
+ pattern);
+ else
+ pg_log_error("Did not find any session variables.");
+ }
+ else
+ {
+ myopt.nullPrint = NULL;
+ myopt.title = _("List of variables");
+ myopt.translate_header = true;
+ myopt.translate_columns = translate_columns;
+ myopt.n_translate_columns = lengthof(translate_columns);
+
+ printQuery(res, &myopt, pset.queryFout, false, pset.logfile);
+ }
+
+ PQclear(res);
+ return true;
+}
/*
* \dFp
diff --git a/src/bin/psql/describe.h b/src/bin/psql/describe.h
index 18ecaa60949..55ced4aab7b 100644
--- a/src/bin/psql/describe.h
+++ b/src/bin/psql/describe.h
@@ -149,4 +149,7 @@ extern bool listOpFamilyFunctions(const char *access_method_pattern,
/* \dl or \lo_list */
extern bool listLargeObjects(bool verbose);
+/* \dV */
+extern bool listVariables(const char *pattern, bool varbose);
+
#endif /* DESCRIBE_H */
diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index 403b51325a7..81886eb9725 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -261,6 +261,7 @@ slashUsage(unsigned short int pager)
HELP0(" \\dT[Sx+] [PATTERN] list data types\n");
HELP0(" \\du[Sx+] [PATTERN] list roles\n");
HELP0(" \\dv[Sx+] [PATTERN] list views\n");
+ HELP0(" \\dV[x+] [PATTERN] list session variables\n");
HELP0(" \\dx[x+] [PATTERN] list extensions\n");
HELP0(" \\dX[x] [PATTERN] list extended statistics\n");
HELP0(" \\dy[x+] [PATTERN] list event triggers\n");
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index ec65ab79fec..7fe19a568f1 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -970,6 +970,13 @@ static const SchemaQuery Query_for_trigger_of_table = {
.refnamespace = "c1.relnamespace",
};
+static const SchemaQuery Query_for_list_of_variables = {
+ .min_server_version = 180000,
+ .catname = "pg_catalog.pg_variable v",
+ .viscondition = "pg_catalog.pg_variable_is_visible(v.oid)",
+ .namespace = "v.varnamespace",
+ .result = "v.varname",
+};
/*
* Queries to get lists of names of various kinds of things, possibly
@@ -1318,6 +1325,7 @@ static const pgsql_thing_t words_after_create[] = {
* TABLE ... */
{"USER", Query_for_list_of_roles, NULL, NULL, Keywords_for_user_thing},
{"USER MAPPING FOR", NULL, NULL, NULL},
+ {"VARIABLE", NULL, NULL, &Query_for_list_of_variables},
{"VIEW", NULL, NULL, &Query_for_list_of_views},
{NULL} /* end of list */
};
@@ -1883,7 +1891,7 @@ psql_completion(const char *text, int start, int end)
"\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL",
"\\dm", "\\dn", "\\do", "\\dO", "\\dp", "\\dP", "\\dPi", "\\dPt",
"\\drds", "\\drg", "\\dRs", "\\dRp", "\\ds",
- "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy",
+ "\\dt", "\\dT", "\\dv", "\\du", "\\dx", "\\dX", "\\dy", "\\dV",
"\\echo", "\\edit", "\\ef", "\\elif", "\\else", "\\encoding",
"\\endif", "\\endpipeline", "\\errverbose", "\\ev",
"\\f", "\\flush", "\\flushrequest",
@@ -2592,6 +2600,9 @@ match_previous_words(int pattern_id,
"ALL");
else if (Matches("ALTER", "SYSTEM", "SET", MatchAny))
COMPLETE_WITH("TO");
+ /* ALTER VARIABLE <name> */
+ else if (Matches("ALTER", "VARIABLE", MatchAny))
+ COMPLETE_WITH("OWNER TO", "RENAME TO", "SET SCHEMA");
/* ALTER VIEW <name> */
else if (Matches("ALTER", "VIEW", MatchAny))
COMPLETE_WITH("ALTER COLUMN", "OWNER TO", "RENAME", "RESET", "SET");
@@ -3175,7 +3186,7 @@ match_previous_words(int pattern_id,
"ROUTINE", "RULE", "SCHEMA", "SEQUENCE", "SERVER",
"STATISTICS", "SUBSCRIPTION", "TABLE",
"TABLESPACE", "TEXT SEARCH", "TRANSFORM FOR",
- "TRIGGER", "TYPE", "VIEW");
+ "TRIGGER", "TYPE", "VARIABLE", "VIEW");
else if (Matches("COMMENT", "ON", "ACCESS", "METHOD"))
COMPLETE_WITH_QUERY(Query_for_list_of_access_methods);
else if (Matches("COMMENT", "ON", "CONSTRAINT"))
@@ -3985,6 +3996,13 @@ match_previous_words(int pattern_id,
else if (TailMatches("=", MatchAnyExcept("*)")))
COMPLETE_WITH(",", ")");
}
+/* CREATE VARIABLE --- is allowed inside CREATE SCHEMA, so use TailMatches */
+ /* Complete CREATE VARIABLE <name> with AS */
+ else if (TailMatches("CREATE", "VARIABLE", MatchAny))
+ COMPLETE_WITH("AS");
+ else if (TailMatches("VARIABLE", MatchAny, "AS"))
+ /* Complete CREATE VARIABLE <name> with AS types */
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
/* CREATE VIEW --- is allowed inside CREATE SCHEMA, so use TailMatches */
/* Complete CREATE [ OR REPLACE ] VIEW <name> with AS or WITH */
@@ -4262,6 +4280,12 @@ match_previous_words(int pattern_id,
else if (Matches("DROP", "TRANSFORM", "FOR", MatchAny, "LANGUAGE", MatchAny))
COMPLETE_WITH("CASCADE", "RESTRICT");
+ /* DROP VARIABLE */
+ else if (Matches("DROP", "VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
+ else if (Matches("DROP", "VARIABLE", MatchAny))
+ COMPLETE_WITH("CASCADE", "RESTRICT");
+
/* EXECUTE */
else if (Matches("EXECUTE"))
COMPLETE_WITH_QUERY(Query_for_list_of_prepared_statements);
@@ -4463,7 +4487,9 @@ match_previous_words(int pattern_id,
* objects supported.
*/
if (HeadMatches("ALTER", "DEFAULT", "PRIVILEGES"))
- COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES", "ROUTINES", "TYPES", "SCHEMAS", "LARGE OBJECTS");
+ COMPLETE_WITH("TABLES", "SEQUENCES", "FUNCTIONS", "PROCEDURES",
+ "ROUTINES", "TYPES", "SCHEMAS", "LARGE OBJECTS",
+ "VARIABLES");
else
COMPLETE_WITH_SCHEMA_QUERY_PLUS(Query_for_list_of_grantables,
"ALL FUNCTIONS IN SCHEMA",
@@ -4471,6 +4497,7 @@ match_previous_words(int pattern_id,
"ALL ROUTINES IN SCHEMA",
"ALL SEQUENCES IN SCHEMA",
"ALL TABLES IN SCHEMA",
+ "ALL VARIABLES IN SCHEMA",
"DATABASE",
"DOMAIN",
"FOREIGN DATA WRAPPER",
@@ -4485,7 +4512,8 @@ match_previous_words(int pattern_id,
"SEQUENCE",
"TABLE",
"TABLESPACE",
- "TYPE");
+ "TYPE",
+ "VARIABLE");
}
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "ALL") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "ALL"))
@@ -4493,7 +4521,8 @@ match_previous_words(int pattern_id,
"PROCEDURES IN SCHEMA",
"ROUTINES IN SCHEMA",
"SEQUENCES IN SCHEMA",
- "TABLES IN SCHEMA");
+ "TABLES IN SCHEMA",
+ "VARIABLES IN SCHEMA");
else if (TailMatches("GRANT|REVOKE", MatchAny, "ON", "FOREIGN") ||
TailMatches("REVOKE", "GRANT", "OPTION", "FOR", MatchAny, "ON", "FOREIGN"))
COMPLETE_WITH("DATA WRAPPER", "SERVER");
@@ -4529,6 +4558,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_tablespaces);
else if (TailMatches("TYPE"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_datatypes);
+ else if (TailMatches("VARIABLE"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatches("GRANT", MatchAny, MatchAny, MatchAny))
COMPLETE_WITH("TO");
else
@@ -4831,7 +4862,7 @@ match_previous_words(int pattern_id,
/* PREPARE xx AS */
else if (Matches("PREPARE", MatchAny, "AS"))
- COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM");
+ COMPLETE_WITH("SELECT", "UPDATE", "INSERT INTO", "DELETE FROM", "LET");
/*
* PREPARE TRANSACTION is missing on purpose. It's intended for transaction
@@ -5320,6 +5351,8 @@ match_previous_words(int pattern_id,
COMPLETE_WITH_QUERY(Query_for_list_of_roles);
else if (TailMatchesCS("\\dv*"))
COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_views);
+ else if (TailMatchesCS("\\dV*"))
+ COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_variables);
else if (TailMatchesCS("\\dx*"))
COMPLETE_WITH_QUERY(Query_for_list_of_extensions);
else if (TailMatchesCS("\\dX*"))
diff --git a/src/include/catalog/Makefile b/src/include/catalog/Makefile
index 2bbc7805fe3..f98760de635 100644
--- a/src/include/catalog/Makefile
+++ b/src/include/catalog/Makefile
@@ -81,7 +81,8 @@ CATALOG_HEADERS := \
pg_publication_namespace.h \
pg_publication_rel.h \
pg_subscription.h \
- pg_subscription_rel.h
+ pg_subscription_rel.h \
+ pg_variable.h
GENERATED_HEADERS := $(CATALOG_HEADERS:%.h=%_d.h)
diff --git a/src/include/catalog/meson.build b/src/include/catalog/meson.build
index ec1cf467f6f..81398efa7c9 100644
--- a/src/include/catalog/meson.build
+++ b/src/include/catalog/meson.build
@@ -69,6 +69,7 @@ catalog_headers = [
'pg_publication_rel.h',
'pg_subscription.h',
'pg_subscription_rel.h',
+ 'pg_variable.h',
]
# The .dat files we need can just be listed alphabetically.
diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index 8c7ccc69a3c..bdac0c13bec 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -97,6 +97,8 @@ extern Oid TypenameGetTypid(const char *typname);
extern Oid TypenameGetTypidExtended(const char *typname, bool temp_ok);
extern bool TypeIsVisible(Oid typid);
+extern bool VariableIsVisible(Oid varid);
+
extern FuncCandidateList FuncnameGetCandidates(List *names,
int nargs, List *argnames,
bool expand_variadic,
@@ -169,6 +171,10 @@ extern SearchPathMatcher *GetSearchPathMatcher(MemoryContext context);
extern SearchPathMatcher *CopySearchPathMatcher(SearchPathMatcher *path);
extern bool SearchPathMatchesCurrentEnvironment(SearchPathMatcher *path);
+extern List *NamesFromList(List *names);
+extern Oid LookupVariable(const char *nspname, const char *varname, bool missing_ok);
+extern Oid LookupVariableFromNameList(List *names, bool missing_ok);
+
extern Oid get_collation_oid(List *collname, bool missing_ok);
extern Oid get_conversion_oid(List *conname, bool missing_ok);
extern Oid FindDefaultConversionProc(int32 for_encoding, int32 to_encoding);
diff --git a/src/include/catalog/pg_default_acl.h b/src/include/catalog/pg_default_acl.h
index ce6e5098eaf..087d35b943d 100644
--- a/src/include/catalog/pg_default_acl.h
+++ b/src/include/catalog/pg_default_acl.h
@@ -69,6 +69,7 @@ MAKE_SYSCACHE(DEFACLROLENSPOBJ, pg_default_acl_role_nsp_obj_index, 8);
#define DEFACLOBJ_TYPE 'T' /* type */
#define DEFACLOBJ_NAMESPACE 'n' /* namespace */
#define DEFACLOBJ_LARGEOBJECT 'L' /* large object */
+#define DEFACLOBJ_VARIABLE 'V' /* variable */
#endif /* EXPOSE_TO_CLIENT_CODE */
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 62beb71da28..da772ff9e17 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5466,6 +5466,26 @@
prorettype => 'bool', proargtypes => 'oid oid text',
prosrc => 'has_largeobject_privilege_id_id' },
+{ oid => '9613', descr => 'user privilege on session variable by username, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name text text',
+ prosrc => 'has_session_variable_privilege_name_name' },
+{ oid => '9614', descr => 'user privilege on session variable by username, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'name oid text', prosrc => 'has_session_variable_privilege_name_id' },
+{ oid => '9615', descr => 'user privilege on session variable by user oid, seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text text', prosrc => 'has_session_variable_privilege_id_name' },
+{ oid => '9616', descr => 'user privilege on session variable by user oid, seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid oid text', prosrc => 'has_session_variable_privilege_id_id' },
+{ oid => '9617', descr => 'current user privilege on session variable by seq name',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'text text', prosrc => 'has_session_variable_privilege_name' },
+{ oid => '9618', descr => 'current user privilege on session variable by seq oid',
+ proname => 'has_session_variable_privilege', provolatile => 's', prorettype => 'bool',
+ proargtypes => 'oid text', prosrc => 'has_session_variable_privilege_id' },
+
{ oid => '3355', descr => 'I/O',
proname => 'pg_ndistinct_in', prorettype => 'pg_ndistinct',
proargtypes => 'cstring', prosrc => 'pg_ndistinct_in' },
@@ -6676,6 +6696,9 @@
proname => 'pg_collation_is_visible', procost => '10', provolatile => 's',
prorettype => 'bool', proargtypes => 'oid',
prosrc => 'pg_collation_is_visible' },
+{ oid => '9999', descr => 'is session variable visible in search path?',
+ proname => 'pg_variable_is_visible', procost => '10', provolatile => 's',
+ prorettype => 'bool', proargtypes => 'oid', prosrc => 'pg_variable_is_visible' },
{ oid => '2854', descr => 'get OID of current session\'s temp schema, if any',
proname => 'pg_my_temp_schema', provolatile => 's', proparallel => 'r',
diff --git a/src/include/catalog/pg_variable.h b/src/include/catalog/pg_variable.h
new file mode 100644
index 00000000000..3d3c6eb24b5
--- /dev/null
+++ b/src/include/catalog/pg_variable.h
@@ -0,0 +1,81 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_variable.h
+ * definition of session variables system catalog (pg_variables)
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/catalog/pg_variable.h
+ *
+ * NOTES
+ * The Catalog.pm module reads this file and derives schema
+ * information.
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PG_VARIABLE_H
+#define PG_VARIABLE_H
+
+#include "catalog/genbki.h"
+#include "catalog/objectaddress.h"
+#include "catalog/pg_variable_d.h"
+#include "utils/acl.h"
+
+/* ----------------
+ * pg_variable definition. cpp turns this into
+ * typedef struct FormData_pg_variable
+ * ----------------
+ */
+CATALOG(pg_variable,9222,VariableRelationId)
+{
+ Oid oid; /* oid */
+
+ /* OID of entry in pg_type for variable's type */
+ Oid vartype BKI_LOOKUP(pg_type);
+
+ /* variable name */
+ NameData varname;
+
+ /* OID of namespace containing variable class */
+ Oid varnamespace BKI_LOOKUP(pg_namespace);
+
+ /* variable owner */
+ Oid varowner BKI_LOOKUP(pg_authid);
+
+ /* typmod for variable's type */
+ int32 vartypmod BKI_DEFAULT(-1);
+
+ /* variable collation */
+ Oid varcollation BKI_DEFAULT(0) BKI_LOOKUP_OPT(pg_collation);
+
+
+#ifdef CATALOG_VARLEN /* variable-length fields start here */
+
+ /* access permissions */
+ aclitem varacl[1] BKI_DEFAULT(_null_);
+
+#endif
+} FormData_pg_variable;
+
+/* ----------------
+ * Form_pg_variable corresponds to a pointer to a tuple with
+ * the format of the pg_variable relation.
+ * ----------------
+ */
+typedef FormData_pg_variable *Form_pg_variable;
+
+DECLARE_TOAST(pg_variable, 9223, 9224);
+
+DECLARE_UNIQUE_INDEX_PKEY(pg_variable_oid_index, 9225, VariableOidIndexId, pg_variable, btree(oid oid_ops));
+DECLARE_UNIQUE_INDEX(pg_variable_varname_nsp_index, 9226, VariableNameNspIndexId, pg_variable, btree(varname name_ops, varnamespace oid_ops));
+
+extern ObjectAddress CreateVariable(ParseState *pstate,
+ CreateSessionVarStmt *stmt);
+extern void DropVariableById(Oid varid);
+
+MAKE_SYSCACHE(VARIABLENAMENSP, pg_variable_varname_nsp_index, 8);
+MAKE_SYSCACHE(VARIABLEOID, pg_variable_oid_index, 8);
+
+#endif /* PG_VARIABLE_H */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 4610fc61293..ae4b6a3862c 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2365,6 +2365,7 @@ typedef enum ObjectType
OBJECT_TSTEMPLATE,
OBJECT_TYPE,
OBJECT_USER_MAPPING,
+ OBJECT_VARIABLE,
OBJECT_VIEW,
} ObjectType;
@@ -3515,6 +3516,21 @@ typedef struct AlterStatsStmt
bool missing_ok; /* skip error if statistics object is missing */
} AlterStatsStmt;
+
+/* ----------------------
+ * {Create|Alter} VARIABLE Statement
+ * ----------------------
+ */
+typedef struct CreateSessionVarStmt
+{
+ NodeTag type;
+ RangeVar *variable; /* the variable to create */
+ TypeName *typeName; /* the type of variable */
+ CollateClause *collClause;
+ bool if_not_exists; /* do nothing if it already exists */
+} CreateSessionVarStmt;
+
+
/* ----------------------
* Create Function Statement
* ----------------------
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index a4af3f717a1..0ea0265de7c 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -486,6 +486,8 @@ PG_KEYWORD("validator", VALIDATOR, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("value", VALUE_P, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("values", VALUES, COL_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("varchar", VARCHAR, COL_NAME_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variable", VARIABLE, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("variables", VARIABLES, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("variadic", VARIADIC, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("varying", VARYING, UNRESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("verbose", VERBOSE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
diff --git a/src/include/tcop/cmdtaglist.h b/src/include/tcop/cmdtaglist.h
index d250a714d59..ea86954dded 100644
--- a/src/include/tcop/cmdtaglist.h
+++ b/src/include/tcop/cmdtaglist.h
@@ -68,6 +68,7 @@ PG_CMDTAG(CMDTAG_ALTER_TRANSFORM, "ALTER TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TRIGGER, "ALTER TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_TYPE, "ALTER TYPE", true, true, false)
PG_CMDTAG(CMDTAG_ALTER_USER_MAPPING, "ALTER USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_ALTER_VARIABLE, "ALTER VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_ALTER_VIEW, "ALTER VIEW", true, false, false)
PG_CMDTAG(CMDTAG_ANALYZE, "ANALYZE", false, false, false)
PG_CMDTAG(CMDTAG_BEGIN, "BEGIN", false, false, false)
@@ -123,6 +124,7 @@ PG_CMDTAG(CMDTAG_CREATE_TRANSFORM, "CREATE TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TRIGGER, "CREATE TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_TYPE, "CREATE TYPE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_USER_MAPPING, "CREATE USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_CREATE_VARIABLE, "CREATE VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_CREATE_VIEW, "CREATE VIEW", true, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE, "DEALLOCATE", false, false, false)
PG_CMDTAG(CMDTAG_DEALLOCATE_ALL, "DEALLOCATE ALL", false, false, false)
@@ -175,6 +177,7 @@ PG_CMDTAG(CMDTAG_DROP_TRANSFORM, "DROP TRANSFORM", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TRIGGER, "DROP TRIGGER", true, false, false)
PG_CMDTAG(CMDTAG_DROP_TYPE, "DROP TYPE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_USER_MAPPING, "DROP USER MAPPING", true, false, false)
+PG_CMDTAG(CMDTAG_DROP_VARIABLE, "DROP VARIABLE", true, false, false)
PG_CMDTAG(CMDTAG_DROP_VIEW, "DROP VIEW", true, false, false)
PG_CMDTAG(CMDTAG_EXECUTE, "EXECUTE", false, false, false)
PG_CMDTAG(CMDTAG_EXPLAIN, "EXPLAIN", false, false, false)
diff --git a/src/include/utils/acl.h b/src/include/utils/acl.h
index 01ae5b719fd..5e1a8a82e90 100644
--- a/src/include/utils/acl.h
+++ b/src/include/utils/acl.h
@@ -169,6 +169,7 @@ typedef struct ArrayType Acl;
#define ACL_ALL_RIGHTS_SCHEMA (ACL_USAGE|ACL_CREATE)
#define ACL_ALL_RIGHTS_TABLESPACE (ACL_CREATE)
#define ACL_ALL_RIGHTS_TYPE (ACL_USAGE)
+#define ACL_ALL_RIGHTS_VARIABLE (ACL_SELECT|ACL_UPDATE)
/* operation codes for pg_*_aclmask */
typedef enum
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index fa7c7e0323b..f4a851dc232 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -139,6 +139,7 @@ extern char get_func_prokind(Oid funcid);
extern bool get_func_leakproof(Oid funcid);
extern RegProcedure get_func_support(Oid funcid);
extern Oid get_relname_relid(const char *relname, Oid relnamespace);
+extern Oid get_varname_varid(const char *varname, Oid varnamespace);
extern char *get_rel_name(Oid relid);
extern Oid get_rel_namespace(Oid relid);
extern Oid get_rel_type_id(Oid relid);
@@ -211,6 +212,14 @@ extern char *get_publication_name(Oid pubid, bool missing_ok);
extern Oid get_subscription_oid(const char *subname, bool missing_ok);
extern char *get_subscription_name(Oid subid, bool missing_ok);
+extern char *get_session_variable_name(Oid varid);
+extern Oid get_session_variable_namespace(Oid varid);
+extern Oid get_session_variable_type(Oid varid);
+extern void get_session_variable_type_typmod_collid(Oid varid,
+ Oid *typid,
+ int32 *typmod,
+ Oid *collid);
+
#define type_is_array(typid) (get_element_type(typid) != InvalidOid)
/* type_is_array_domain accepts both plain arrays and domains over arrays */
#define type_is_array_domain(typid) (get_base_element_type(typid) != InvalidOid)
diff --git a/src/test/regress/expected/dependency.out b/src/test/regress/expected/dependency.out
index 75a078ada9e..cd8e4412fa9 100644
--- a/src/test/regress/expected/dependency.out
+++ b/src/test/regress/expected/dependency.out
@@ -151,3 +151,20 @@ owner of type deptest_t
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+-- should fail
+DROP DOMAIN vardomain;
+ERROR: cannot drop type vardomain because other objects depend on it
+DETAIL: column c of composite type vartype depends on type vardomain
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+DROP TYPE vartype;
+ERROR: cannot drop type vartype because other objects depend on it
+DETAIL: session variable var1 depends on type vartype
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/expected/oidjoins.out b/src/test/regress/expected/oidjoins.out
index 215eb899be3..d9953321402 100644
--- a/src/test/regress/expected/oidjoins.out
+++ b/src/test/regress/expected/oidjoins.out
@@ -266,3 +266,7 @@ NOTICE: checking pg_subscription {subdbid} => pg_database {oid}
NOTICE: checking pg_subscription {subowner} => pg_authid {oid}
NOTICE: checking pg_subscription_rel {srsubid} => pg_subscription {oid}
NOTICE: checking pg_subscription_rel {srrelid} => pg_class {oid}
+NOTICE: checking pg_variable {vartype} => pg_type {oid}
+NOTICE: checking pg_variable {varnamespace} => pg_namespace {oid}
+NOTICE: checking pg_variable {varowner} => pg_authid {oid}
+NOTICE: checking pg_variable {varcollation} => pg_collation {oid}
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index cf48ae6d0c2..fd6b2a6b8c8 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -6023,6 +6023,30 @@ COMMIT;
# final ON_ERROR_ROLLBACK: off
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+-------------------+-------------
+ public | var1 | character varying | C | regress_variable_owner | |
+(1 row)
+
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+ List of variables
+ Schema | Name | Type | Collation | Owner | Access privileges | Description
+--------+------+-------------------+-----------+------------------------+--------------------------------------------------+------------------
+ public | var1 | character varying | C | regress_variable_owner | regress_variable_owner=rw/regress_variable_owner+| some description
+ | | | | | =r/regress_variable_owner |
+(1 row)
+
+DROP VARIABLE var1;
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
-- check describing invalid multipart names
\dA regression.heap
improper qualified name (too many dotted names): regression.heap
@@ -6244,6 +6268,12 @@ cross-database references are not implemented: nonesuch.public.func_deps_stat
improper qualified name (too many dotted names): regression.myevt
\dy nonesuch.myevt
improper qualified name (too many dotted names): nonesuch.myevt
+\dV host.regression.public.var
+improper qualified name (too many dotted names): host.regression.public.var
+\dV regression|mydb.public.var
+cross-database references are not implemented: regression|mydb.public.var
+\dV nonesuch.public.var
+cross-database references are not implemented: nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
List of access methods
@@ -6478,6 +6508,12 @@ List of schemas
------+-------+-------+---------+----------+------
(0 rows)
+\dV "no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
improper qualified name (too many dotted names): "no.such.schema"."no.such.access.method"
@@ -6647,6 +6683,12 @@ improper qualified name (too many dotted names): "no.such.schema"."no.such.insta
\dy "no.such.schema"."no.such.event.trigger"
improper qualified name (too many dotted names): "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
List of tables
@@ -6780,6 +6822,12 @@ List of text search templates
--------+------+------------+-----------+--------------+-----
(0 rows)
+\dV regression."no.such.schema"."no.such.variable"
+ List of variables
+ Schema | Name | Type | Collation | Owner
+--------+------+------+-----------+-------
+(0 rows)
+
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -6827,6 +6875,8 @@ cross-database references are not implemented: "no.such.database"."no.such.schem
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
+cross-database references are not implemented: "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
CREATE ROLE regress_du_role1;
diff --git a/src/test/regress/expected/session_variables.out b/src/test/regress/expected/session_variables.out
new file mode 100644
index 00000000000..c36660ce6d3
--- /dev/null
+++ b/src/test/regress/expected/session_variables.out
@@ -0,0 +1,433 @@
+CREATE ROLE regress_variable_owner;
+SET log_statement TO ddl;
+-- should be ok
+CREATE VARIABLE var1 AS int;
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+ERROR: session variable cannot be pseudo-type anyelement
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+NOTICE: session variable "var2" does not exist, skipping
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+NOTICE: session variable "var1" already exists, skipping
+-- should fail
+CREATE VARIABLE var1 AS int;
+ERROR: session variable "var1" already exists
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TABLE t1;
+ERROR: cannot drop table t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+ERROR: cannot alter table "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TABLE t1;
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+-- should fail
+DROP TYPE t1;
+ERROR: cannot drop type t1 because other objects depend on it
+DETAIL: session variable var1 depends on type t1
+HINT: Use DROP ... CASCADE to drop the dependent objects too.
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+ERROR: cannot alter type "t1" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+DROP TYPE t1;
+SET log_statement TO default;
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+CREATE VARIABLE var1 AS testvar_domain;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter domain "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+CREATE VARIABLE var1 AS testvar_type;
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+ERROR: cannot alter type "testvar_domain" because session variable "public.var1" uses it
+DROP VARIABLE var1;
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+NOTICE: NORMAL: orig=t normal=f istemp=f type=session variable identity=public.var1 name={public,var1} args={}
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+ obj_description
+-----------------------
+ some variable comment
+(1 row)
+
+DROP VARIABLE var1;
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+ varname | descr | type | object_names | object_args | ident
+---------------+-----------------------------------------+------------------+--------------------------+-------------+--------------------------------------------------------------------
+ svartest_var1 | session variable vartest1.svartest_var1 | session variable | {vartest1,svartest_var1} | {} | ("session variable",vartest1,svartest_var1,vartest1.svartest_var1)
+ svartest_var1 | session variable vartest2.svartest_var1 | session variable | {vartest2,svartest_var1} | {} | ("session variable",vartest2,svartest_var1,vartest2.svartest_var1)
+(2 rows)
+
+DROP SCHEMA vartest1 CASCADE;
+NOTICE: drop cascades to session variable vartest1.svartest_var1
+DROP SCHEMA vartest2 CASCADE;
+NOTICE: drop cascades to session variable vartest2.svartest_var1
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE ROLE regress_variable_reader;
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+DROP VARIABLE public.varxx;
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE public.var1 AS int;
+SET search_path TO public;
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+ ?column?
+----------
+ t
+(1 row)
+
+SET ROLE TO regress_variable_r1;
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+ has_session_variable_privilege
+--------------------------------
+ f
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+ has_session_variable_privilege
+--------------------------------
+ t
+(1 row)
+
+--
+-- end of function has_session_variable_privilege tests.
+--
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+DROP VARIABLE public.var1;
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+DROP ROLE regress_variable_owner;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index a424be2a6bf..b96a8de001d 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -115,7 +115,7 @@ test: json jsonb json_encoding jsonpath jsonpath_encoding jsonb_jsonpath sqljson
# NB: temp.sql does reconnects which transiently use 2 connections,
# so keep this parallel group to at most 19 tests
# ----------
-test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml
+test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion truncate alter_table sequence polymorphism rowtypes returning largeobject with xml session_variables
# ----------
# Another group of parallel tests
diff --git a/src/test/regress/sql/dependency.sql b/src/test/regress/sql/dependency.sql
index 8d74ed7122c..6c18b7f840a 100644
--- a/src/test/regress/sql/dependency.sql
+++ b/src/test/regress/sql/dependency.sql
@@ -114,3 +114,17 @@ DROP USER regress_dep_user2;
DROP OWNED BY regress_dep_user2, regress_dep_user0;
DROP USER regress_dep_user2;
DROP USER regress_dep_user0;
+
+-- dependency on type
+CREATE DOMAIN vardomain AS int;
+CREATE TYPE vartype AS (a int, b int, c vardomain);
+CREATE VARIABLE var1 AS vartype;
+
+-- should fail
+DROP DOMAIN vardomain;
+DROP TYPE vartype;
+
+-- clean up
+DROP VARIABLE var1;
+DROP TYPE vartype;
+DROP DOMAIN vardomain;
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index 1a8a83462f0..b567ee1eee2 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -1643,6 +1643,19 @@ COMMIT;
DROP TABLE bla;
DROP FUNCTION psql_error;
+-- session variable test
+CREATE ROLE regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS varchar COLLATE "C";
+\dV+ var1
+GRANT SELECT ON VARIABLE var1 TO PUBLIC;
+COMMENT ON VARIABLE var1 IS 'some description';
+\dV+ var1
+DROP VARIABLE var1;
+
+SET ROLE TO DEFAULT;
+DROP ROLE regress_variable_owner;
+
-- check describing invalid multipart names
\dA regression.heap
\dA nonesuch.heap
@@ -1754,6 +1767,9 @@ DROP FUNCTION psql_error;
\dX nonesuch.public.func_deps_stat
\dy regression.myevt
\dy nonesuch.myevt
+\dV host.regression.public.var
+\dV regression|mydb.public.var
+\dV nonesuch.public.var
-- check that dots within quoted name segments are not counted
\dA "no.such.access.method"
@@ -1795,6 +1811,8 @@ DROP FUNCTION psql_error;
\dx "no.such.installed.extension"
\dX "no.such.extended.statistics"
\dy "no.such.event.trigger"
+\dV "no.such.variable"
+
-- again, but with dotted schema qualifications.
\dA "no.such.schema"."no.such.access.method"
@@ -1835,6 +1853,7 @@ DROP FUNCTION psql_error;
\dx "no.such.schema"."no.such.installed.extension"
\dX "no.such.schema"."no.such.extended.statistics"
\dy "no.such.schema"."no.such.event.trigger"
+\dV "no.such.schema"."no.such.variable"
-- again, but with current database and dotted schema qualifications.
\dt regression."no.such.schema"."no.such.table.relation"
@@ -1859,6 +1878,7 @@ DROP FUNCTION psql_error;
\dP regression."no.such.schema"."no.such.partitioned.relation"
\dT regression."no.such.schema"."no.such.data.type"
\dX regression."no.such.schema"."no.such.extended.statistics"
+\dV regression."no.such.schema"."no.such.variable"
-- again, but with dotted database and dotted schema qualifications.
\dt "no.such.database"."no.such.schema"."no.such.table.relation"
@@ -1884,6 +1904,7 @@ DROP FUNCTION psql_error;
\dP "no.such.database"."no.such.schema"."no.such.partitioned.relation"
\dT "no.such.database"."no.such.schema"."no.such.data.type"
\dX "no.such.database"."no.such.schema"."no.such.extended.statistics"
+\dV "no.such.database"."no.such.schema"."no.such.variable"
-- check \drg and \du
CREATE ROLE regress_du_role0;
diff --git a/src/test/regress/sql/session_variables.sql b/src/test/regress/sql/session_variables.sql
new file mode 100644
index 00000000000..eeb0f94ca3c
--- /dev/null
+++ b/src/test/regress/sql/session_variables.sql
@@ -0,0 +1,297 @@
+CREATE ROLE regress_variable_owner;
+
+SET log_statement TO ddl;
+
+-- should be ok
+CREATE VARIABLE var1 AS int;
+
+-- should fail, pseudotypes are not allowed
+CREATE VARIABLE var2 AS anyelement;
+
+-- should be ok, do nothing
+DROP VARIABLE IF EXISTS var2;
+
+-- do nothing
+CREATE VARIABLE IF NOT EXISTS var1 AS int;
+
+-- should fail
+CREATE VARIABLE var1 AS int;
+
+-- should be ok
+DROP VARIABLE IF EXISTS var1;
+
+-- the variable can use composite types
+CREATE TABLE t1 (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TABLE t1;
+
+-- should be ok
+ALTER TABLE t1 ADD COLUMN c int;
+
+-- should fail
+ALTER TABLE t1 ALTER COLUMN b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TABLE t1;
+
+CREATE TYPE t1 AS (a int, b int);
+CREATE VARIABLE var1 AS t1;
+
+-- should fail
+DROP TYPE t1;
+
+-- should be ok
+ALTER TYPE t1 ADD ATTRIBUTE c int;
+
+-- should fail
+ALTER TYPE t1 ALTER ATTRIBUTE b TYPE numeric;
+
+DROP VARIABLE var1;
+DROP TYPE t1;
+
+SET log_statement TO default;
+
+CREATE DOMAIN testvar_domain AS int;
+CREATE TYPE testvar_type AS (a testvar_domain);
+
+CREATE VARIABLE var1 AS testvar_domain;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+CREATE VARIABLE var1 AS testvar_type;
+
+-- should fail
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP VARIABLE var1;
+
+-- should be ok
+ALTER DOMAIN testvar_domain ADD CHECK(value <> 100);
+
+DROP TYPE testvar_type;
+DROP TYPE testvar_domain;
+
+-- check event trigger support
+CREATE OR REPLACE FUNCTION svar_event_trigger_report_dropped()
+RETURNS event_trigger
+AS $$
+DECLARE r record;
+BEGIN
+ FOR r IN SELECT * from pg_event_trigger_dropped_objects()
+ LOOP
+ CONTINUE WHEN NOT r.normal AND NOT r.original;
+
+ RAISE NOTICE
+ 'NORMAL: orig=% normal=% istemp=% type=% identity=% name=% args=%',
+ r.original, r.normal, r.is_temporary, r.object_type,
+ r.object_identity, r.address_names, r.address_args;
+ END LOOP;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE EVENT TRIGGER svar_regress_event_trigger_report_dropped ON sql_drop
+ WHEN TAG IN ('DROP VARIABLE')
+ EXECUTE PROCEDURE svar_event_trigger_report_dropped();
+
+CREATE VARIABLE var1 AS int;
+DROP VARIABLE var1;
+
+DROP EVENT TRIGGER svar_regress_event_trigger_report_dropped;
+
+-- check comment on variable
+CREATE VARIABLE var1 AS int;
+COMMENT ON VARIABLE var1 IS 'some variable comment';
+SELECT pg_catalog.obj_description(oid, 'pg_variable') FROM pg_variable WHERE varname = 'var1';
+
+DROP VARIABLE var1;
+
+-- check the object address of all session variables
+CREATE SCHEMA vartest1;
+CREATE SCHEMA vartest2;
+CREATE VARIABLE vartest1.svartest_var1 AS int;
+CREATE VARIABLE vartest2.svartest_var1 AS int;
+
+SELECT
+ e.varname,
+ pg_describe_object('pg_variable'::regclass, e.oid, 0) as descr,
+ b.type, b.object_names, b.object_args,
+ pg_identify_object(a.classid, a.objid, a.objsubid) as ident
+FROM pg_variable as e,
+ LATERAL pg_identify_object_as_address('pg_variable'::regclass, e.oid, 0) as b,
+ LATERAL pg_get_object_address(b.type, b.object_names, b.object_args) as a
+WHERE e.varname LIKE 'svartest_var%';
+
+DROP SCHEMA vartest1 CASCADE;
+DROP SCHEMA vartest2 CASCADE;
+
+-- check access rights and supported ALTER
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+
+CREATE ROLE regress_variable_reader;
+
+GRANT SELECT ON VARIABLE svartest.var1 TO regress_variable_reader;
+REVOKE ALL ON VARIABLE svartest.var1 FROM regress_variable_reader;
+
+ALTER VARIABLE svartest.var1 OWNER TO regress_variable_owner;
+ALTER VARIABLE svartest.var1 RENAME TO varxx;
+ALTER VARIABLE svartest.varxx SET SCHEMA public;
+
+DROP VARIABLE public.varxx;
+
+ALTER DEFAULT PRIVILEGES
+ FOR ROLE regress_variable_owner
+ IN SCHEMA svartest
+ GRANT SELECT ON VARIABLES TO regress_variable_reader;
+
+-- creating variable with default privileges
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE svartest.var1 AS int;
+SET ROLE TO DEFAULT;
+
+-- should be ok. since ALTER DEFAULT PRIVILEGES
+-- allow regress_variable_reader to have SELECT priviledge
+SELECT has_session_variable_privilege('regress_variable_reader', 'svartest.var1', 'SELECT'); -- t
+
+DROP VARIABLE svartest.var1;
+DROP SCHEMA svartest;
+DROP ROLE regress_variable_reader;
+
+--
+-- begin of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+CREATE ROLE regress_variable_r1;
+CREATE ROLE regress_variable_r2;
+
+SET ROLE TO regress_variable_owner;
+CREATE VARIABLE var1 AS int; --var1 will owned by regress_variable_owner
+
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r1 WITH GRANT OPTION;
+SET ROLE TO regress_variable_r1;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2 WITH GRANT OPTION;
+SET ROLE TO DEFAULT;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL PRIVILEGES ON VARIABLE var1 FROM regress_variable_r1 CASCADE;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+
+SET ROLE TO regress_variable_owner;
+GRANT SELECT ON VARIABLE var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- t
+
+REVOKE ALL ON VARIABLE var1 FROM regress_variable_r2 GRANTED BY regress_variable_owner;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'public.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_owner', 'public.var1', 'SELECT'); -- t
+SET ROLE TO DEFAULT;
+
+DROP VARIABLE var1;
+--
+-- end of check GRANT WITH GRANT OPTION and REVOKE GRANTED BY
+--
+
+--
+-- begin of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+CREATE SCHEMA svartest;
+GRANT ALL ON SCHEMA svartest TO regress_variable_owner;
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE svartest.var1 AS int;
+CREATE VARIABLE svartest.var2 AS int;
+
+GRANT SELECT ON ALL VARIABLES IN SCHEMA svartest TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- t
+
+REVOKE SELECT ON ALL VARIABLES IN SCHEMA svartest FROM regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var1', 'SELECT'); -- f
+SELECT has_session_variable_privilege('regress_variable_r1', 'svartest.var2', 'SELECT'); -- f
+
+SET ROLE TO DEFAULT;
+DROP VARIABLE svartest.var1;
+DROP VARIABLE svartest.var2;
+DROP SCHEMA svartest;
+--
+-- end of test: GRANT|REVOKE SELECT|UPDATE ON ALL VARIABLES IN SCHEMA
+--
+
+--
+-- function has_session_variable_privilege have various kind of signature.
+-- the following are extensive test for it.
+--
+SET ROLE TO regress_variable_owner;
+
+CREATE VARIABLE public.var1 AS int;
+
+SET search_path TO public;
+
+GRANT SELECT ON VARIABLE public.var1 TO regress_variable_r1;
+GRANT SELECT, UPDATE ON VARIABLE public.var1 TO regress_variable_r2;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.var1', 'SELECT');
+SELECT has_session_variable_privilege('regress_variable_r1', 'public.notexists', 'SELECT') IS NULL;
+
+SET ROLE TO regress_variable_r1;
+
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT oid AS varid
+ FROM pg_variable
+ WHERE varname = 'var1' AND varnamespace = 'public'::regnamespace \gset
+
+SELECT has_session_variable_privilege('var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('var1', 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1', :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2', :varid, 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege(:varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege(:varid, 'UPDATE'); -- f
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, 'var1', 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, 'var1', 'UPDATE'); -- t
+
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r1'::regrole, :varid, 'UPDATE'); -- f
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'SELECT'); -- t
+SELECT has_session_variable_privilege('regress_variable_r2'::regrole, :varid, 'UPDATE'); -- t
+--
+-- end of function has_session_variable_privilege tests.
+--
+
+SET ROLE TO DEFAULT;
+SET search_path TO DEFAULT;
+
+DROP VARIABLE public.var1;
+
+DROP ROLE regress_variable_r1;
+DROP ROLE regress_variable_r2;
+
+DROP ROLE regress_variable_owner;
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 9ea573fae21..9dc16940b9d 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -562,6 +562,7 @@ CreateRoleStmt
CreateSchemaStmt
CreateSchemaStmtContext
CreateSeqStmt
+CreateSessionVarStmt
CreateStatsStmt
CreateStmt
CreateStmtContext
@@ -907,6 +908,7 @@ FormData_pg_ts_parser
FormData_pg_ts_template
FormData_pg_type
FormData_pg_user_mapping
+FormData_pg_variable
FormExtraData_pg_attribute
Form_pg_aggregate
Form_pg_am
@@ -966,6 +968,7 @@ Form_pg_ts_parser
Form_pg_ts_template
Form_pg_type
Form_pg_user_mapping
+Form_pg_variable
FormatNode
FreeBlockNumberArray
FreeListData
@@ -3188,6 +3191,7 @@ VarString
VarStringSortSupport
Variable
VariableAssignHook
+VariableInfo
VariableSetKind
VariableSetStmt
VariableShowStmt
--
2.49.0
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-05-20 14:56 ` Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Bruce Momjian @ 2025-05-20 14:56 UTC (permalink / raw)
To: Pavel Stehule <[email protected]>; +Cc: Marcos Pegoraro <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
On Thu, May 15, 2025 at 08:48:37AM +0200, Pavel Stehule wrote:
> Hi
>
> fresh rebase
I will again ask why this patch set is being reposted when there is no
plan to apply it to git master?
--
Bruce Momjian <[email protected]> https://momjian.us
EDB https://enterprisedb.com
Do not let urgent matters crowd out time for investment in the future.
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
@ 2025-05-20 16:33 ` Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Marcos Pegoraro @ 2025-05-20 16:33 UTC (permalink / raw)
To: Bruce Momjian <[email protected]>; +Cc: Pavel Stehule <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
Em ter., 20 de mai. de 2025 às 11:56, Bruce Momjian <[email protected]>
escreveu:
> I will again ask why this patch set is being reposted when there is no
> plan to apply it to git master
Too bad. I would love to have this functionality, from the user's point of
view there are problems where it would solve them wonderfully. I don't know
technically of what prevents it from being natively on core, but it would
be great, it would definitely be.
regards
Marcos
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
@ 2025-05-20 16:39 ` Bruce Momjian <[email protected]>
2025-05-20 18:47 ` Re: proposal: schema variables Daniel Gustafsson <[email protected]>
2025-05-20 20:28 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
0 siblings, 2 replies; 32+ messages in thread
From: Bruce Momjian @ 2025-05-20 16:39 UTC (permalink / raw)
To: Marcos Pegoraro <[email protected]>; +Cc: Pavel Stehule <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
On Tue, May 20, 2025 at 01:33:18PM -0300, Marcos Pegoraro wrote:
> Em ter., 20 de mai. de 2025 às 11:56, Bruce Momjian <[email protected]>
> escreveu:
>
> I will again ask why this patch set is being reposted when there is no
> plan to apply it to git master
>
> Too bad. I would love to have this functionality, from the user's point of view
> there are problems where it would solve them wonderfully. I don't know
> technically of what prevents it from being natively on core, but it would be
> great, it would definitely be.
My only point is that we should only be using email lists for work that
is being actively worked on to be added to community Postgres. There
has been talk of a trimmed-down version of this being applied, but I
don't see any work in that direction.
This patch should be moved to a separate location where perhaps people
can subscribe to updates when they are posted, perhaps github.
--
Bruce Momjian <[email protected]> https://momjian.us
EDB https://enterprisedb.com
Do not let urgent matters crowd out time for investment in the future.
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
@ 2025-05-20 18:47 ` Daniel Gustafsson <[email protected]>
2025-05-20 20:28 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
1 sibling, 1 reply; 32+ messages in thread
From: Daniel Gustafsson @ 2025-05-20 18:47 UTC (permalink / raw)
To: Bruce Momjian <[email protected]>; +Cc: Marcos Pegoraro <[email protected]>; Pavel Stehule <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
> On 20 May 2025, at 18:39, Bruce Momjian <[email protected]> wrote:
>
> On Tue, May 20, 2025 at 01:33:18PM -0300, Marcos Pegoraro wrote:
>> Em ter., 20 de mai. de 2025 às 11:56, Bruce Momjian <[email protected]>
>> escreveu:
>>
>> I will again ask why this patch set is being reposted when there is no
>> plan to apply it to git master
>>
>> Too bad. I would love to have this functionality, from the user's point of view
>> there are problems where it would solve them wonderfully. I don't know
>> technically of what prevents it from being natively on core, but it would be
>> great, it would definitely be.
>
> My only point is that we should only be using email lists for work that
> is being actively worked on to be added to community Postgres. There
> has been talk of a trimmed-down version of this being applied, but I
> don't see any work in that direction.
>
> This patch should be moved to a separate location where perhaps people
> can subscribe to updates when they are posted, perhaps github.
As a project with no roadmap governed by open forum consensus I don't think we
have any right to tell community members what they can or cannot work on here,
any technical discussion which conforms with our published policies should be
welcome. If Pavel want's to continue rebasing his patchset here then he has,
IMHO, every right to do so.
Whether or not a committer will show interest at some point is another thing,
but we are seeing a very good role-model for taking responsibility for ones
work here at the very least =)
--
Daniel Gustafsson
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 18:47 ` Re: proposal: schema variables Daniel Gustafsson <[email protected]>
@ 2025-05-20 20:28 ` Bruce Momjian <[email protected]>
2025-05-20 20:36 ` Re: proposal: schema variables Laurenz Albe <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Bruce Momjian @ 2025-05-20 20:28 UTC (permalink / raw)
To: Daniel Gustafsson <[email protected]>; +Cc: Marcos Pegoraro <[email protected]>; Pavel Stehule <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
On Tue, May 20, 2025 at 08:47:36PM +0200, Daniel Gustafsson wrote:
> > On 20 May 2025, at 18:39, Bruce Momjian <[email protected]> wrote:
> > My only point is that we should only be using email lists for work that
> > is being actively worked on to be added to community Postgres. There
> > has been talk of a trimmed-down version of this being applied, but I
> > don't see any work in that direction.
> >
> > This patch should be moved to a separate location where perhaps people
> > can subscribe to updates when they are posted, perhaps github.
>
> As a project with no roadmap governed by open forum consensus I don't think we
> have any right to tell community members what they can or cannot work on here,
> any technical discussion which conforms with our published policies should be
> welcome. If Pavel want's to continue rebasing his patchset here then he has,
> IMHO, every right to do so.
>
> Whether or not a committer will show interest at some point is another thing,
> but we are seeing a very good role-model for taking responsibility for ones
> work here at the very least =)
Well, we do have a right, e.g., we would not allow someone to repeatedly
post patches for a Postgres extension we don't manage, or the jdbc
driver. I also don't think we would allow someone to continue posting
patches for a feature we have decided to reject, and I think we have
decided to reject the patch in in its current form. I think we might
accept a trimmed-down version, but I don't see the patch moving in that
direction.
Now, of course, if I am the only one who feels this way, I can suppress
these emails on my end.
--
Bruce Momjian <[email protected]> https://momjian.us
EDB https://enterprisedb.com
Do not let urgent matters crowd out time for investment in the future.
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 18:47 ` Re: proposal: schema variables Daniel Gustafsson <[email protected]>
2025-05-20 20:28 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
@ 2025-05-20 20:36 ` Laurenz Albe <[email protected]>
2025-05-20 21:06 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Laurenz Albe @ 2025-05-20 20:36 UTC (permalink / raw)
To: Bruce Momjian <[email protected]>; Daniel Gustafsson <[email protected]>; +Cc: Marcos Pegoraro <[email protected]>; Pavel Stehule <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
On Tue, 2025-05-20 at 16:28 -0400, Bruce Momjian wrote:
> On Tue, May 20, 2025 at 08:47:36PM +0200, Daniel Gustafsson wrote:
> > > On 20 May 2025, at 18:39, Bruce Momjian <[email protected]> wrote:
> > > My only point is that we should only be using email lists for work that
> > > is being actively worked on to be added to community Postgres. There
> > > has been talk of a trimmed-down version of this being applied, but I
> > > don't see any work in that direction.
> > >
> > > This patch should be moved to a separate location where perhaps people
> > > can subscribe to updates when they are posted, perhaps github.
> >
> > As a project with no roadmap governed by open forum consensus I don't think we
> > have any right to tell community members what they can or cannot work on here,
> > any technical discussion which conforms with our published policies should be
> > welcome. If Pavel want's to continue rebasing his patchset here then he has,
> > IMHO, every right to do so.
> >
> > Whether or not a committer will show interest at some point is another thing,
> > but we are seeing a very good role-model for taking responsibility for ones
> > work here at the very least =)
>
> Well, we do have a right, e.g., we would not allow someone to repeatedly
> post patches for a Postgres extension we don't manage, or the jdbc
> driver. I also don't think we would allow someone to continue posting
> patches for a feature we have decided to reject, and I think we have
> decided to reject the patch in in its current form. I think we might
> accept a trimmed-down version, but I don't see the patch moving in that
> direction.
>
> Now, of course, if I am the only one who feels this way, I can suppress
> these emails on my end.
In my opinion, this patch set is adding something that would be valuable to
have in core.
If no committer intends to pick it up and commit it, I think the proper
action would be to step up and reject the patch set, not complain about the
insistence of the author.
Yours,
Laurenz Albe
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 18:47 ` Re: proposal: schema variables Daniel Gustafsson <[email protected]>
2025-05-20 20:28 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 20:36 ` Re: proposal: schema variables Laurenz Albe <[email protected]>
@ 2025-05-20 21:06 ` Bruce Momjian <[email protected]>
2025-05-21 05:15 ` Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-21 06:27 ` Re: proposal: schema variables Laurenz Albe <[email protected]>
0 siblings, 2 replies; 32+ messages in thread
From: Bruce Momjian @ 2025-05-20 21:06 UTC (permalink / raw)
To: Laurenz Albe <[email protected]>; +Cc: Daniel Gustafsson <[email protected]>; Marcos Pegoraro <[email protected]>; Pavel Stehule <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
On Tue, May 20, 2025 at 10:36:54PM +0200, Laurenz Albe wrote:
> On Tue, 2025-05-20 at 16:28 -0400, Bruce Momjian wrote:
> > Well, we do have a right, e.g., we would not allow someone to repeatedly
> > post patches for a Postgres extension we don't manage, or the jdbc
> > driver. I also don't think we would allow someone to continue posting
> > patches for a feature we have decided to reject, and I think we have
> > decided to reject the patch in in its current form. I think we might
> > accept a trimmed-down version, but I don't see the patch moving in that
> > direction.
> >
> > Now, of course, if I am the only one who feels this way, I can suppress
> > these emails on my end.
>
> In my opinion, this patch set is adding something that would be valuable to
> have in core.
>
> If no committer intends to pick it up and commit it, I think the proper
> action would be to step up and reject the patch set, not complain about the
> insistence of the author.
Are you saying I should not complain until we have officially rejected
the patch set? If we officially reject it, the patch author would no
longer post it?
--
Bruce Momjian <[email protected]> https://momjian.us
EDB https://enterprisedb.com
Do not let urgent matters crowd out time for investment in the future.
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 18:47 ` Re: proposal: schema variables Daniel Gustafsson <[email protected]>
2025-05-20 20:28 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 20:36 ` Re: proposal: schema variables Laurenz Albe <[email protected]>
2025-05-20 21:06 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
@ 2025-05-21 05:15 ` Pavel Stehule <[email protected]>
2025-05-21 20:41 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
1 sibling, 1 reply; 32+ messages in thread
From: Pavel Stehule @ 2025-05-21 05:15 UTC (permalink / raw)
To: Bruce Momjian <[email protected]>; +Cc: Laurenz Albe <[email protected]>; Daniel Gustafsson <[email protected]>; Marcos Pegoraro <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
út 20. 5. 2025 v 23:07 odesílatel Bruce Momjian <[email protected]> napsal:
> On Tue, May 20, 2025 at 10:36:54PM +0200, Laurenz Albe wrote:
> > On Tue, 2025-05-20 at 16:28 -0400, Bruce Momjian wrote:
> > > Well, we do have a right, e.g., we would not allow someone to
> repeatedly
> > > post patches for a Postgres extension we don't manage, or the jdbc
> > > driver. I also don't think we would allow someone to continue posting
> > > patches for a feature we have decided to reject, and I think we have
> > > decided to reject the patch in in its current form. I think we might
> > > accept a trimmed-down version, but I don't see the patch moving in that
> > > direction.
> > >
> > > Now, of course, if I am the only one who feels this way, I can suppress
> > > these emails on my end.
> >
> > In my opinion, this patch set is adding something that would be valuable
> to
> > have in core.
> >
> > If no committer intends to pick it up and commit it, I think the proper
> > action would be to step up and reject the patch set, not complain about
> the
> > insistence of the author.
>
> Are you saying I should not complain until we have officially rejected
> the patch set? If we officially reject it, the patch author would no
> longer post it?
>
I'll respect committers. I really don't want to worry people in the
community. It is not my way, and I am sorry.
I think this is an important feature - for some group of developers, and
then I push my energy and time for this.
On the other hand, I accept that there is a lot of work that is important
for a wider group of users. So it is. Unfortunately,
without parser's hooks this feature cannot be implemented as an extension.
But parser's hooks was proposed,
and rejected, so there is no other possibility, how to do it. More -
implementation of this feature as an extension is not
best way.
regards
Pavel
>
> --
> Bruce Momjian <[email protected]> https://momjian.us
> EDB https://enterprisedb.com
>
> Do not let urgent matters crowd out time for investment in the future.
>
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 18:47 ` Re: proposal: schema variables Daniel Gustafsson <[email protected]>
2025-05-20 20:28 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 20:36 ` Re: proposal: schema variables Laurenz Albe <[email protected]>
2025-05-20 21:06 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-21 05:15 ` Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-05-21 20:41 ` Bruce Momjian <[email protected]>
0 siblings, 0 replies; 32+ messages in thread
From: Bruce Momjian @ 2025-05-21 20:41 UTC (permalink / raw)
To: Pavel Stehule <[email protected]>; +Cc: Laurenz Albe <[email protected]>; Daniel Gustafsson <[email protected]>; Marcos Pegoraro <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
On Wed, May 21, 2025 at 07:15:27AM +0200, Pavel Stehule wrote:
> út 20. 5. 2025 v 23:07 odesílatel Bruce Momjian <[email protected]> napsal:
> > If no committer intends to pick it up and commit it, I think the proper
> > action would be to step up and reject the patch set, not complain about
> the
> > insistence of the author.
>
> Are you saying I should not complain until we have officially rejected
> the patch set? If we officially reject it, the patch author would no
> longer post it?
>
> I'll respect committers. I really don't want to worry people in the community.
> It is not my way, and I am sorry.
I realize I am being the bad guy by asking these questions, but I don't
think it is good for the project to get distracted with a feature that
isn't progressing, and it is unpleasant for an author to keep working on
something with no clear direction from the community. I am happy to
learn that progress is being made.
I see this feature being first proposed in 2012:
https://www.postgresql.org/message-id/flat/CAFj8pRDdk_4E8HiffbVOfk97iR%2BSLFoZpRT4D2nTE89YU-hQrg%40m...
and the first question was:
I don't really see what we can do with this that we can't do
without this.
Now, I think we have answered that question, and gotten closer to seeing
the complexities of adding this feature.
I am asking that, given its age, we more clearly direct this patch,
either toward completion or rejection.
> I think this is an important feature - for some group of developers, and then I
> push my energy and time for this.
> On the other hand, I accept that there is a lot of work that is important for a
> wider group of users. So it is. Unfortunately,
> without parser's hooks this feature cannot be implemented as an extension. But
> parser's hooks was proposed,
> and rejected, so there is no other possibility, how to do it. More -
> implementation of this feature as an extension is not
> best way.
I will reply to this in my next email.
--
Bruce Momjian <[email protected]> https://momjian.us
EDB https://enterprisedb.com
Do not let urgent matters crowd out time for investment in the future.
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 18:47 ` Re: proposal: schema variables Daniel Gustafsson <[email protected]>
2025-05-20 20:28 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 20:36 ` Re: proposal: schema variables Laurenz Albe <[email protected]>
2025-05-20 21:06 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
@ 2025-05-21 06:27 ` Laurenz Albe <[email protected]>
2025-05-21 06:36 ` Re: proposal: schema variables Pavel Stehule <[email protected]>
1 sibling, 1 reply; 32+ messages in thread
From: Laurenz Albe @ 2025-05-21 06:27 UTC (permalink / raw)
To: Bruce Momjian <[email protected]>; +Cc: Daniel Gustafsson <[email protected]>; Marcos Pegoraro <[email protected]>; Pavel Stehule <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
On Tue, 2025-05-20 at 17:06 -0400, Bruce Momjian wrote:
> f no committer intends to pick it up and commit it, I think the proper
> > action would be to step up and reject the patch set, not complain about the
> > insistence of the author.
>
> Are you saying I should not complain until we have officially rejected
> the patch set? If we officially reject it, the patch author would no
> longer post it?
No, you are free to complain, just as Pavel is free to keep his patch
set from rotting. What I am trying to say is that rejecting the patch
set is the most effective way to complain.
The current state is that Pavel keeps the patch set alive, and occasionally
people review it or parts of it. But no committer is accepting or rejecting
it, so the patch set remains in limbo. This annoys you, and it is certainly
not a happy experience for the author. Rejection is not nice, but at least
it would make it easier for Pavel to move on and spend his energy elsewhere.
Yours,
Laurenz Albe
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 18:47 ` Re: proposal: schema variables Daniel Gustafsson <[email protected]>
2025-05-20 20:28 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 20:36 ` Re: proposal: schema variables Laurenz Albe <[email protected]>
2025-05-20 21:06 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-21 06:27 ` Re: proposal: schema variables Laurenz Albe <[email protected]>
@ 2025-05-21 06:36 ` Pavel Stehule <[email protected]>
0 siblings, 0 replies; 32+ messages in thread
From: Pavel Stehule @ 2025-05-21 06:36 UTC (permalink / raw)
To: Laurenz Albe <[email protected]>; +Cc: Bruce Momjian <[email protected]>; Daniel Gustafsson <[email protected]>; Marcos Pegoraro <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
st 21. 5. 2025 v 8:27 odesílatel Laurenz Albe <[email protected]>
napsal:
> On Tue, 2025-05-20 at 17:06 -0400, Bruce Momjian wrote:
> > f no committer intends to pick it up and commit it, I think the proper
> > > action would be to step up and reject the patch set, not complain
> about the
> > > insistence of the author.
> >
> > Are you saying I should not complain until we have officially rejected
> > the patch set? If we officially reject it, the patch author would no
> > longer post it?
>
> No, you are free to complain, just as Pavel is free to keep his patch
> set from rotting. What I am trying to say is that rejecting the patch
> set is the most effective way to complain.
>
> The current state is that Pavel keeps the patch set alive, and occasionally
> people review it or parts of it. But no committer is accepting or
> rejecting
> it, so the patch set remains in limbo. This annoys you, and it is
> certainly
> not a happy experience for the author. Rejection is not nice, but at least
> it would make it easier for Pavel to move on and spend his energy
> elsewhere.
>
Rejection is not nice, but it can be, and if it will be, I hope, there will
be more cleaner
status if we want this feature or not, and if possibly want this feature,
what we expect.
This feature can be designed differently in respect to some priorities. But
without known
priorities, any patch, proposal can end in the same state.
Regards
Pavel
>
> Yours,
> Laurenz Albe
>
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
@ 2025-05-20 20:28 ` Pavel Stehule <[email protected]>
2025-05-20 21:10 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-21 00:21 ` Re: Re: proposal: schema variables Michael Paquier <[email protected]>
1 sibling, 2 replies; 32+ messages in thread
From: Pavel Stehule @ 2025-05-20 20:28 UTC (permalink / raw)
To: Bruce Momjian <[email protected]>; +Cc: Marcos Pegoraro <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
Hi
út 20. 5. 2025 v 18:39 odesílatel Bruce Momjian <[email protected]> napsal:
> On Tue, May 20, 2025 at 01:33:18PM -0300, Marcos Pegoraro wrote:
> > Em ter., 20 de mai. de 2025 às 11:56, Bruce Momjian <[email protected]>
> > escreveu:
> >
> > I will again ask why this patch set is being reposted when there is
> no
> > plan to apply it to git master
> >
> > Too bad. I would love to have this functionality, from the user's point
> of view
> > there are problems where it would solve them wonderfully. I don't know
> > technically of what prevents it from being natively on core, but it
> would be
> > great, it would definitely be.
>
> My only point is that we should only be using email lists for work that
> is being actively worked on to be added to community Postgres. There
> has been talk of a trimmed-down version of this being applied, but I
> don't see any work in that direction.
>
I sent a reduced version a few months ago - from 21 patches to 8 (and it
can be reduced to six if we postpone tools for detection ambiguity).
The timing was not perfect - the focus was and it is concentrated to finish
pg18.
I am very sorry if this topic and patches bother anyone. I am afraid if I
close it to some personal github, it will not be visible, and I am sure this
feature is missing in Postgres. Today we have few workarounds. Some
workarounds are not available everywhere, some workarounds cannot
be used for security. With integrated solutions some scenarios can be done
more easily, more secure, faster, more comfortable. It is true, so
mentioned scenarios are not "hot" today. Stored procedures or RLS or
migration procedures from other databases are not extra common. But
who uses it, then he misses session variables.
This topic is difficult, because there is no common solution. SQL/PSM is
almost dead. T-SQL (and MySQL) design is weak and cannot be used for
security.
Oracle's design is joined with just one environment. And although almost
all widely used databases have supported session variables for decades, no
one design
is perfect. Proposed design is not perfect too (it introduces possible
ambiguity) , but I think it can support most wanted use cases (can be
enhanced in future),
and it is consistent with Postgres. There are more ways to reduce risk of
unwanted ambiguity to zero. But it increases the size of the patch.
Regards
Pavel
>
> This patch should be moved to a separate location where perhaps people
> can subscribe to updates when they are posted, perhaps github.
>
> --
> Bruce Momjian <[email protected]> https://momjian.us
> EDB https://enterprisedb.com
>
> Do not let urgent matters crowd out time for investment in the future.
>
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 20:28 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-05-20 21:10 ` Bruce Momjian <[email protected]>
1 sibling, 0 replies; 32+ messages in thread
From: Bruce Momjian @ 2025-05-20 21:10 UTC (permalink / raw)
To: Pavel Stehule <[email protected]>; +Cc: Marcos Pegoraro <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Michael Paquier <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
On Tue, May 20, 2025 at 10:28:31PM +0200, Pavel Stehule wrote:
> út 20. 5. 2025 v 18:39 odesílatel Bruce Momjian <[email protected]> napsal:
> I sent a reduced version a few months ago - from 21 patches to 8 (and it can be
> reduced to six if we postpone tools for detection ambiguity).
> The timing was not perfect - the focus was and it is concentrated to finish
> pg18.
It was not clear to me that this patch set was being reduced to make it
more likely it would be accepted? I thought it was the same patch set
since 20??.
> I am very sorry if this topic and patches bother anyone. I am afraid if I close
> it to some personal github, it will not be visible, and I am sure this
> feature is missing in Postgres. Today we have few workarounds. Some workarounds
> are not available everywhere, some workarounds cannot
> be used for security. With integrated solutions some scenarios can be done more
> easily, more secure, faster, more comfortable. It is true, so
> mentioned scenarios are not "hot" today. Stored procedures or RLS or migration
> procedures from other databases are not extra common. But
> who uses it, then he misses session variables.
Understood. If people feel it is progressing toward acceptance, I
certainly withdraw my objection and apologize.
--
Bruce Momjian <[email protected]> https://momjian.us
EDB https://enterprisedb.com
Do not let urgent matters crowd out time for investment in the future.
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 20:28 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-05-21 00:21 ` Michael Paquier <[email protected]>
2025-05-21 05:49 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
1 sibling, 1 reply; 32+ messages in thread
From: Michael Paquier @ 2025-05-21 00:21 UTC (permalink / raw)
To: Pavel Stehule <[email protected]>; +Cc: Bruce Momjian <[email protected]>; Marcos Pegoraro <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
On Tue, May 20, 2025 at 10:28:31PM +0200, Pavel Stehule wrote:
> This topic is difficult, because there is no common solution. SQL/PSM is
> almost dead. T-SQL (and MySQL) design is weak and cannot be used for
> security.
> Oracle's design is joined with just one environment. And although almost
> all widely used databases have supported session variables for decades, no
> one design
> is perfect. Proposed design is not perfect too (it introduces possible
> ambiguity) , but I think it can support most wanted use cases (can be
> enhanced in future),
> and it is consistent with Postgres. There are more ways to reduce risk of
> unwanted ambiguity to zero. But it increases the size of the patch.
One thing that I keep hearing about this feature is that this would be
really helpful for migration from Oracle to PostgreSQL, helping a lot
with rewrites of pl/pgsql functions.
There is one page on the wiki about private variables, dating back to
2016:
https://wiki.postgresql.org/wiki/CREATE_PRIVATE_VARIABLE
Perhaps it would help to summarize a bit the pros and cons of existing
implementations to drive which implementation would be the most suited
on a wiki page? The way standards are defined is by overwriting
existing standards, and we don't have one in the SQL specification.
It's hard to say if there will be one at some point, but if the main
SQL products around the world have one, it pretty much is a point in
favor of having a standard.
Another possible angle that could be taken is to invest in a proposal
for the SQL committee to consider, forcing an actual standard that
PostgreSQL could rely on rather than having one behavior implemented
to have it standard-incompatible a few years after. And luckily, we
have Vik Fearing and Peter Eisentraut in this community who invest
time and resources in this area.
FWIW, I do agree with the opinion that if you want to propose rebased
versions of this patch set on a periodic basis, you are free to do so.
This is the core concept of an open community. In terms of my
committer time, I'm pretty much already booked in terms of features
planned for the next release, so I guess that I won't be able to
invest time on this thread. Just saying.
I know that this patch set has been discussed at FOSDEM at some point,
so others may be able to comment more about that. That's just one
opinion among many others.
--
Michael
Attachments:
[application/pgp-signature] signature.asc (833B, ../../[email protected]/2-signature.asc)
download
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 20:28 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-21 00:21 ` Re: Re: proposal: schema variables Michael Paquier <[email protected]>
@ 2025-05-21 05:49 ` Pavel Stehule <[email protected]>
2025-05-21 21:23 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
0 siblings, 1 reply; 32+ messages in thread
From: Pavel Stehule @ 2025-05-21 05:49 UTC (permalink / raw)
To: Michael Paquier <[email protected]>; Peter Eisentraut <[email protected]>; +Cc: Bruce Momjian <[email protected]>; Marcos Pegoraro <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
st 21. 5. 2025 v 2:21 odesílatel Michael Paquier <[email protected]>
napsal:
> On Tue, May 20, 2025 at 10:28:31PM +0200, Pavel Stehule wrote:
> > This topic is difficult, because there is no common solution. SQL/PSM is
> > almost dead. T-SQL (and MySQL) design is weak and cannot be used for
> > security.
> > Oracle's design is joined with just one environment. And although almost
> > all widely used databases have supported session variables for decades,
> no
> > one design
> > is perfect. Proposed design is not perfect too (it introduces possible
> > ambiguity) , but I think it can support most wanted use cases (can be
> > enhanced in future),
> > and it is consistent with Postgres. There are more ways to reduce risk of
> > unwanted ambiguity to zero. But it increases the size of the patch.
>
> One thing that I keep hearing about this feature is that this would be
> really helpful for migration from Oracle to PostgreSQL, helping a lot
> with rewrites of pl/pgsql functions.
>
> There is one page on the wiki about private variables, dating back to
> 2016:
> https://wiki.postgresql.org/wiki/CREATE_PRIVATE_VARIABLE
>
>
I wrote mail
https://www.postgresql.org/message-id/[email protected]...
and there is another wiki page
https://wiki.postgresql.org/wiki/Variable_Design
> Perhaps it would help to summarize a bit the pros and cons of existing
> implementations to drive which implementation would be the most suited
> on a wiki page? The way standards are defined is by overwriting
> existing standards, and we don't have one in the SQL specification.
> It's hard to say if there will be one at some point, but if the main
> SQL products around the world have one, it pretty much is a point in
> favor of having a standard.
>
Although it is maybe a peccant idea - I can imagine two different
implementations of server side session variables with different syntaxes
(and different advantages and disadvantages, and different use cases). The
implementations are not going against, but we should to accept
fact, so one feature is implemented twice. We should choose just one, that
will be implemented first. Proposed helps with migration from
PL/SQL.
>
> Another possible angle that could be taken is to invest in a proposal
> for the SQL committee to consider, forcing an actual standard that
> PostgreSQL could rely on rather than having one behavior implemented
> to have it standard-incompatible a few years after. And luckily, we
> have Vik Fearing and Peter Eisentraut in this community who invest
> time and resources in this area.
>
Theoretically the proposed design is a subset of implementation from DB2 -
I designed it without knowledge of this DB2 feature. But without
introduction of concept of modules (that is partially redundant to
schemas), this design is very natural and I am very sure, so there is not
another way, how to design it. We can ask Peter or Vik about real
possibilities in this area. I have not any information from this area, just
I haven't seen the changes in SQL/PSM for decades, so I didn't think about
it.
> FWIW, I do agree with the opinion that if you want to propose rebased
> versions of this patch set on a periodic basis, you are free to do so.
> This is the core concept of an open community. In terms of my
> committer time, I'm pretty much already booked in terms of features
> planned for the next release, so I guess that I won't be able to
> invest time on this thread. Just saying.
>
thank you for an info
> I know that this patch set has been discussed at FOSDEM at some point,
> so others may be able to comment more about that. That's just one
> opinion among many others.
> --
> Michael
>
^ permalink raw reply [nested|flat] 32+ messages in thread
* Re: Re: proposal: schema variables
2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 20:28 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-21 00:21 ` Re: Re: proposal: schema variables Michael Paquier <[email protected]>
2025-05-21 05:49 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
@ 2025-05-21 21:23 ` Bruce Momjian <[email protected]>
0 siblings, 0 replies; 32+ messages in thread
From: Bruce Momjian @ 2025-05-21 21:23 UTC (permalink / raw)
To: Pavel Stehule <[email protected]>; +Cc: Michael Paquier <[email protected]>; Peter Eisentraut <[email protected]>; Marcos Pegoraro <[email protected]>; jian he <[email protected]>; Dmitry Dolgov <[email protected]>; Laurenz Albe <[email protected]>; Erik Rijkers <[email protected]>; Amit Kapila <[email protected]>; DUVAL REMI <[email protected]>; PostgreSQL Hackers <[email protected]>
On Wed, May 21, 2025 at 07:49:34AM +0200, Pavel Stehule wrote:
> st 21. 5. 2025 v 2:21 odesílatel Michael Paquier <[email protected]> napsal:
> One thing that I keep hearing about this feature is that this would be
> really helpful for migration from Oracle to PostgreSQL, helping a lot
> with rewrites of pl/pgsql functions.
>
> There is one page on the wiki about private variables, dating back to
> 2016:
> https://wiki.postgresql.org/wiki/CREATE_PRIVATE_VARIABLE
>
> I wrote mail
>
> https://www.postgresql.org/message-id/
> CAFj8pRB8kdWQCdN2X1_63c58+07Oy4Z+ruDK_xPTUP+Pe8R2Pw@mail.gmail.com
>
> and there is another wiki page https://wiki.postgresql.org/wiki/Variable_Design
Yes, these URLs are very helpful, thanks.
--
Bruce Momjian <[email protected]> https://momjian.us
EDB https://enterprisedb.com
Do not let urgent matters crowd out time for investment in the future.
^ permalink raw reply [nested|flat] 32+ messages in thread
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2025-02-12 04:43 Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-16 09:13 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-02-20 20:22 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-01 07:23 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 18:32 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-03-17 20:52 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-03-18 05:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-02 06:46 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-04-05 10:33 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-15 06:48 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 14:56 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 16:33 ` Re: Re: proposal: schema variables Marcos Pegoraro <[email protected]>
2025-05-20 16:39 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 18:47 ` Re: proposal: schema variables Daniel Gustafsson <[email protected]>
2025-05-20 20:28 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-20 20:36 ` Re: proposal: schema variables Laurenz Albe <[email protected]>
2025-05-20 21:06 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-21 05:15 ` Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-21 20:41 ` Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-21 06:27 ` Re: proposal: schema variables Laurenz Albe <[email protected]>
2025-05-21 06:36 ` Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 20:28 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-20 21:10 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
2025-05-21 00:21 ` Re: Re: proposal: schema variables Michael Paquier <[email protected]>
2025-05-21 05:49 ` Re: Re: proposal: schema variables Pavel Stehule <[email protected]>
2025-05-21 21:23 ` Re: Re: proposal: schema variables Bruce Momjian <[email protected]>
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