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help / color / mirror / Atom feedFrom: Tatsuo Ishii <[email protected]>
To: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Subject: Re: Add RESPECT/IGNORE NULLS and FROM FIRST/LAST options
Date: Thu, 02 Oct 2025 21:15:50 +0900 (JST)
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
<CAGMVOdtM_Ur=DO2MbddNKRMsN5+BbFqTs679rt7hfiWzjMo0ag@mail.gmail.com>
<[email protected]>
> Thank you for the patch. (I noticed int8 is also missing).
>
> I have looked into the commit 964d01ae90c3 which was made by Peter. I
> have quick read through the discussion to know why uint8/uint16 (and
> int8) are missing in gen_node_support.pl. Unfortunately I have no
> clear idea why these data types are missing in the script.
>
> Peter,
> Maybe you wanted to limit the data types that are actually used at
> that point? If so, probably we should only add uint8 support this time
> (uint8 is only needed to implement $Subject for now). What do you
> think?
I decided not to include the fix to gen_node_support.pl for now and
commit the patch without it. We could revisit it later on.
So here is the commit message I would like to propose.
For the technical part please look at the message.
Non technical part:
First of all the author is Oliver (no doubt). I would like to be
listed as a co-author since I wrote the not null cache part.
Next is reviewers. Actually the first effor to implement null
treatment clause was back to 9.3 era (2013) at least. After that
multiple trials to implemnt the feature happend but they had faded
away. I think we don't need to include all of those who joined the old
discussions as reviewers. So I started to check from the discussion:
https://postgr.es/m/flat/CAGMVOdsbtRwE_4+v8zjH1d9xfovDeQAGLkP_B6k69_VoFEgX-A@mail.gmail.com
because it's refered to by the commit fest entry.
Oliver and others, I love to hear your comment!
BTW, Oliver's last patch made the CF bot to misunderstand the patch
contents, which was not actually the main patch. So I attach the same
patch as v20.
----------------------------------------------------------------------
Add IGNORE NULLS/RESPECT NULLS option to Window functions.
Add IGNORE NULLS/RESPECT NULLS option (null treatment clause) to lead,
lag, first_value, last_value and nth_value window functions. If
unspecified, the default is RESPECT NULLS which includes NULL values
in any result calculation. IGNORE NULLS ignores NULL values.
Built-in window functions are modified to call new API
WinCheckAndInitializeNullTreatment() to indicate whether they accept
IGNORE NULLS/RESPECT NULLS option or not (the API can be called by
user defined window functions as well). If WinGetFuncArgInPartition's
allowNullTreatment argument is true and IGNORE NULLS option is given,
WinGetFuncArgInPartition() or WinGetFuncArgInFrame() will return
evaluated function's argument expression on specified non NULL row (if
it exists) in the partition or the frame.
When IGNORE NULLS option is given, window functions need to visit and
evaluate same rows over and over again to look for non null rows. To
mitigate the issue, 2-bit not null information array is created while
executing window functions to remember whether the row has been
already evaluated to NULL or NOT NULL. If already evaluated, we could
skip some the evaluation work, thus we could get better performance.
Author: Oliver Ford <[email protected]>
Co-authored-by: Tatsuo Ishii <[email protected]>
Reviewed-by: Andrew Gierth <[email protected]>
Reviewed-by: Tom Lane <[email protected]>
Reviewed-by: David Fetter <[email protected]>
Reviewed-by: Vik Fearing <[email protected]>
Reviewed-by: "David G. Johnston" <[email protected]>
Reviewed-by: Krasiyan Andreev <[email protected]>
Reviewed-by: Chao Li <[email protected]>
Discussion: https://postgr.es/m/flat/CAGMVOdsbtRwE_4+v8zjH1d9xfovDeQAGLkP_B6k69_VoFEgX-A@mail.gmail.com
----------------------------------------------------------------------
Best regards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp
Attachments:
[application/octet-stream] v20-0001-Modify-parse-analysis-modules-to-accept-RESPECT-.patch (8.3K, ../[email protected]/2-v20-0001-Modify-parse-analysis-modules-to-accept-RESPECT-.patch)
download | inline diff:
From cb9575f920fae82e2a0e7b40f243fb6980054244 Mon Sep 17 00:00:00 2001
From: Tatsuo Ishii <[email protected]>
Date: Thu, 2 Oct 2025 21:06:40 +0900
Subject: [PATCH v20 1/6] Modify parse/analysis modules to accept
RESPECT/IGNORE NULLS option.
Following changes have been made to parse//analysis modules.
- add IGNORE_P RESPECT_P keywords
- add "null_treatment" to func_expr after filter_clause and before
over_clause as the SQL standard requries. null_treatment is resolved
to either PARSER_IGNORE_NULLS, PARSER_RESPECT_NULLS or
NO_NULLTREATMENT
- add "ignore_nulls" to WindowFunc and FuncCall
---
src/backend/parser/gram.y | 19 ++++++++++++++-----
src/backend/parser/parse_func.c | 9 +++++++++
src/include/nodes/parsenodes.h | 1 +
src/include/nodes/primnodes.h | 13 +++++++++++++
src/include/parser/kwlist.h | 2 ++
5 files changed, 39 insertions(+), 5 deletions(-)
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index f1def67ac7c..57bf7a7c7f2 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -632,7 +632,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
%type <list> window_clause window_definition_list opt_partition_clause
%type <windef> window_definition over_clause window_specification
opt_frame_clause frame_extent frame_bound
-%type <ival> opt_window_exclusion_clause
+%type <ival> null_treatment opt_window_exclusion_clause
%type <str> opt_existing_window_name
%type <boolean> opt_if_not_exists
%type <boolean> opt_unique_null_treatment
@@ -730,7 +730,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
HANDLER HAVING HEADER_P HOLD HOUR_P
- IDENTITY_P IF_P ILIKE IMMEDIATE IMMUTABLE IMPLICIT_P IMPORT_P IN_P INCLUDE
+ IDENTITY_P IF_P IGNORE_P ILIKE IMMEDIATE IMMUTABLE IMPLICIT_P IMPORT_P IN_P INCLUDE
INCLUDING INCREMENT INDENT INDEX INDEXES INHERIT INHERITS INITIALLY INLINE_P
INNER_P INOUT INPUT_P INSENSITIVE INSERT INSTEAD INT_P INTEGER
INTERSECT INTERVAL INTO INVOKER IS ISNULL ISOLATION
@@ -765,7 +765,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
RANGE READ REAL REASSIGN RECURSIVE REF_P REFERENCES REFERENCING
REFRESH REINDEX RELATIVE_P RELEASE RENAME REPEATABLE REPLACE REPLICA
- RESET RESTART RESTRICT RETURN RETURNING RETURNS REVOKE RIGHT ROLE ROLLBACK ROLLUP
+ RESET RESPECT_P RESTART RESTRICT RETURN RETURNING RETURNS REVOKE RIGHT ROLE ROLLBACK ROLLUP
ROUTINE ROUTINES ROW ROWS RULE
SAVEPOINT SCALAR SCHEMA SCHEMAS SCROLL SEARCH SECOND_P SECURITY SELECT
@@ -15805,7 +15805,7 @@ func_application: func_name '(' ')'
* (Note that many of the special SQL functions wouldn't actually make any
* sense as functional index entries, but we ignore that consideration here.)
*/
-func_expr: func_application within_group_clause filter_clause over_clause
+func_expr: func_application within_group_clause filter_clause null_treatment over_clause
{
FuncCall *n = (FuncCall *) $1;
@@ -15838,7 +15838,8 @@ func_expr: func_application within_group_clause filter_clause over_clause
n->agg_within_group = true;
}
n->agg_filter = $3;
- n->over = $4;
+ n->ignore_nulls = $4;
+ n->over = $5;
$$ = (Node *) n;
}
| json_aggregate_func filter_clause over_clause
@@ -16434,6 +16435,12 @@ filter_clause:
/*
* Window Definitions
*/
+null_treatment:
+ IGNORE_P NULLS_P { $$ = PARSER_IGNORE_NULLS; }
+ | RESPECT_P NULLS_P { $$ = PARSER_RESPECT_NULLS; }
+ | /*EMPTY*/ { $$ = NO_NULLTREATMENT; }
+ ;
+
window_clause:
WINDOW window_definition_list { $$ = $2; }
| /*EMPTY*/ { $$ = NIL; }
@@ -17861,6 +17868,7 @@ unreserved_keyword:
| HOUR_P
| IDENTITY_P
| IF_P
+ | IGNORE_P
| IMMEDIATE
| IMMUTABLE
| IMPLICIT_P
@@ -17979,6 +17987,7 @@ unreserved_keyword:
| REPLACE
| REPLICA
| RESET
+ | RESPECT_P
| RESTART
| RESTRICT
| RETURN
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index c43020a769d..778d69c6f3c 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -100,6 +100,7 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
bool agg_star = (fn ? fn->agg_star : false);
bool agg_distinct = (fn ? fn->agg_distinct : false);
bool func_variadic = (fn ? fn->func_variadic : false);
+ int ignore_nulls = (fn ? fn->ignore_nulls : NO_NULLTREATMENT);
CoercionForm funcformat = (fn ? fn->funcformat : COERCE_EXPLICIT_CALL);
bool could_be_projection;
Oid rettype;
@@ -518,6 +519,13 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
errmsg("%s is not an ordered-set aggregate, so it cannot have WITHIN GROUP",
NameListToString(funcname)),
parser_errposition(pstate, location)));
+
+ /* It also can't treat nulls as a window function */
+ if (ignore_nulls != NO_NULLTREATMENT)
+ ereport(ERROR,
+ (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+ errmsg("aggregate functions do not accept RESPECT/IGNORE NULLS"),
+ parser_errposition(pstate, location)));
}
}
else if (fdresult == FUNCDETAIL_WINDOWFUNC)
@@ -840,6 +848,7 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
wfunc->winstar = agg_star;
wfunc->winagg = (fdresult == FUNCDETAIL_AGGREGATE);
wfunc->aggfilter = agg_filter;
+ wfunc->ignore_nulls = ignore_nulls;
wfunc->runCondition = NIL;
wfunc->location = location;
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index ac0e02a1db7..87c1086ec99 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -453,6 +453,7 @@ typedef struct FuncCall
List *agg_order; /* ORDER BY (list of SortBy) */
Node *agg_filter; /* FILTER clause, if any */
struct WindowDef *over; /* OVER clause, if any */
+ int ignore_nulls; /* ignore nulls for window function */
bool agg_within_group; /* ORDER BY appeared in WITHIN GROUP */
bool agg_star; /* argument was really '*' */
bool agg_distinct; /* arguments were labeled DISTINCT */
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 6dfca3cb35b..e9d8bf74145 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -579,6 +579,17 @@ typedef struct GroupingFunc
* Collation information is irrelevant for the query jumbling, as is the
* internal state information of the node like "winstar" and "winagg".
*/
+
+/*
+ * Null Treatment options. If specified, initially set to PARSER_IGNORE_NULLS
+ * which is then converted to IGNORE_NULLS if the window function allows the
+ * null treatment clause.
+ */
+#define NO_NULLTREATMENT 0
+#define PARSER_IGNORE_NULLS 1
+#define PARSER_RESPECT_NULLS 2
+#define IGNORE_NULLS 3
+
typedef struct WindowFunc
{
Expr xpr;
@@ -602,6 +613,8 @@ typedef struct WindowFunc
bool winstar pg_node_attr(query_jumble_ignore);
/* is function a simple aggregate? */
bool winagg pg_node_attr(query_jumble_ignore);
+ /* ignore nulls. One of the Null Treatment options */
+ int ignore_nulls;
/* token location, or -1 if unknown */
ParseLoc location;
} WindowFunc;
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index a4af3f717a1..84182eaaae2 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -202,6 +202,7 @@ PG_KEYWORD("hold", HOLD, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("hour", HOUR_P, UNRESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("identity", IDENTITY_P, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("if", IF_P, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("ignore", IGNORE_P, UNRESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("ilike", ILIKE, TYPE_FUNC_NAME_KEYWORD, BARE_LABEL)
PG_KEYWORD("immediate", IMMEDIATE, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("immutable", IMMUTABLE, UNRESERVED_KEYWORD, BARE_LABEL)
@@ -378,6 +379,7 @@ PG_KEYWORD("repeatable", REPEATABLE, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("replace", REPLACE, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("replica", REPLICA, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("reset", RESET, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("respect", RESPECT_P, UNRESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("restart", RESTART, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("restrict", RESTRICT, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("return", RETURN, UNRESERVED_KEYWORD, BARE_LABEL)
--
2.43.0
[application/octet-stream] v20-0002-Modify-get_windowfunc_expr_helper-to-handle-IGNO.patch (976B, ../[email protected]/3-v20-0002-Modify-get_windowfunc_expr_helper-to-handle-IGNO.patch)
download | inline diff:
From 5e6c7b9306211384933b6c22af816c02ca9c5504 Mon Sep 17 00:00:00 2001
From: Tatsuo Ishii <[email protected]>
Date: Thu, 2 Oct 2025 21:06:40 +0900
Subject: [PATCH v20 2/6] Modify get_windowfunc_expr_helper to handle IGNORE
NULLS option.
---
src/backend/utils/adt/ruleutils.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index c6d83d67b87..21663af6979 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -11091,7 +11091,12 @@ get_windowfunc_expr_helper(WindowFunc *wfunc, deparse_context *context,
get_rule_expr((Node *) wfunc->aggfilter, context, false);
}
- appendStringInfoString(buf, ") OVER ");
+ appendStringInfoString(buf, ") ");
+
+ if (wfunc->ignore_nulls == PARSER_IGNORE_NULLS)
+ appendStringInfoString(buf, "IGNORE NULLS ");
+
+ appendStringInfoString(buf, "OVER ");
if (context->windowClause)
{
--
2.43.0
[application/octet-stream] v20-0003-Modify-eval_const_expressions_mutator-to-handle-.patch (852B, ../[email protected]/4-v20-0003-Modify-eval_const_expressions_mutator-to-handle-.patch)
download | inline diff:
From 1ecce664b714f4a03c57990b1be6a72dd6f26103 Mon Sep 17 00:00:00 2001
From: Tatsuo Ishii <[email protected]>
Date: Thu, 2 Oct 2025 21:06:40 +0900
Subject: [PATCH v20 3/6] Modify eval_const_expressions_mutator to handle
IGNORE NULLS option.
---
src/backend/optimizer/util/clauses.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index f49bde7595b..81d768ff2a2 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -2578,6 +2578,7 @@ eval_const_expressions_mutator(Node *node,
newexpr->winref = expr->winref;
newexpr->winstar = expr->winstar;
newexpr->winagg = expr->winagg;
+ newexpr->ignore_nulls = expr->ignore_nulls;
newexpr->location = expr->location;
return (Node *) newexpr;
--
2.43.0
[application/octet-stream] v20-0004-Modify-executor-and-window-functions-to-handle-I.patch (22.1K, ../[email protected]/5-v20-0004-Modify-executor-and-window-functions-to-handle-I.patch)
download | inline diff:
From cb0805b83d612d845a083d75094cddd22464e3dc Mon Sep 17 00:00:00 2001
From: Tatsuo Ishii <[email protected]>
Date: Thu, 2 Oct 2025 21:06:40 +0900
Subject: [PATCH v20 4/6] Modify executor and window functions to handle IGNORE
NULLS.
Following changes have been made to executor and window functions
modules.
- New window function API WinCheckAndInitializeNullTreatment() is
added. Window functions should call this to express if they accept a
null treatment clause or not. If they do not, an error is raised in
this function. Built-in window functions are modified to call it.
- WinGetFuncArgInPartition is modified to handle IGNORE NULLS.
- WinGetFuncArgInFrame is modified to handle IGNORE NULLS. The actual
workhorse for this is ignorenulls_getfuncarginframe.
- While searching not null rows, to not scan tuples over and over
again, "notnull_info" cache module added. This holds 2-bit info for
each tuple, to keep whether the tuple has already been checked if it
is not yet checked, null or not null. The notnull_info is added to
WindowObjectData.
---
src/backend/executor/nodeWindowAgg.c | 467 +++++++++++++++++++++++++--
src/backend/utils/adt/windowfuncs.c | 10 +
src/include/windowapi.h | 6 +
3 files changed, 448 insertions(+), 35 deletions(-)
diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c
index 9a1acce2b5d..b459c980803 100644
--- a/src/backend/executor/nodeWindowAgg.c
+++ b/src/backend/executor/nodeWindowAgg.c
@@ -69,6 +69,14 @@ typedef struct WindowObjectData
int readptr; /* tuplestore read pointer for this fn */
int64 markpos; /* row that markptr is positioned on */
int64 seekpos; /* row that readptr is positioned on */
+ uint8 *notnull_info; /* not null info */
+ int num_notnull_info; /* track size of the notnull_info array */
+
+ /*
+ * Null treatment options. One of: NO_NULLTREATMENT, PARSER_IGNORE_NULLS,
+ * PARSER_RESPECT_NULLS or IGNORE_NULLS.
+ */
+ int ignore_nulls;
} WindowObjectData;
/*
@@ -96,6 +104,7 @@ typedef struct WindowStatePerFuncData
bool plain_agg; /* is it just a plain aggregate function? */
int aggno; /* if so, index of its WindowStatePerAggData */
+ uint8 ignore_nulls; /* ignore nulls */
WindowObject winobj; /* object used in window function API */
} WindowStatePerFuncData;
@@ -182,8 +191,8 @@ static void begin_partition(WindowAggState *winstate);
static void spool_tuples(WindowAggState *winstate, int64 pos);
static void release_partition(WindowAggState *winstate);
-static int row_is_in_frame(WindowAggState *winstate, int64 pos,
- TupleTableSlot *slot);
+static int row_is_in_frame(WindowObject winobj, int64 pos,
+ TupleTableSlot *slot, bool fetch_tuple);
static void update_frameheadpos(WindowAggState *winstate);
static void update_frametailpos(WindowAggState *winstate);
static void update_grouptailpos(WindowAggState *winstate);
@@ -198,6 +207,34 @@ static bool are_peers(WindowAggState *winstate, TupleTableSlot *slot1,
static bool window_gettupleslot(WindowObject winobj, int64 pos,
TupleTableSlot *slot);
+static Datum ignorenulls_getfuncarginframe(WindowObject winobj, int argno,
+ int relpos, int seektype,
+ bool set_mark, bool *isnull,
+ bool *isout);
+static Datum gettuple_eval_partition(WindowObject winobj, int argno,
+ int64 abs_pos, bool *isnull,
+ bool *isout);
+static void init_notnull_info(WindowObject winobj);
+static void grow_notnull_info(WindowObject winobj, int64 pos);
+static uint8 get_notnull_info(WindowObject winobj, int64 pos);
+static void put_notnull_info(WindowObject winobj, int64 pos, bool isnull);
+
+/*
+ * Not null info bit array consists of 2-bit items
+ */
+#define NN_UNKNOWN 0x00 /* value not calculated yet */
+#define NN_NULL 0x01 /* NULL */
+#define NN_NOTNULL 0x02 /* NOT NULL */
+#define NN_MASK 0x03 /* mask for NOT NULL MAP */
+#define NN_BITS_PER_MEMBER 2 /* number of bit in not null map */
+/* number of items per variable */
+#define NN_ITEM_PER_VAR (BITS_PER_BYTE / NN_BITS_PER_MEMBER)
+/* convert map position to byte offset */
+#define NN_POS_TO_BYTES(pos) ((pos) / NN_ITEM_PER_VAR)
+/* bytes offset to map position */
+#define NN_BYTES_TO_POS(bytes) ((bytes) * NN_ITEM_PER_VAR)
+/* caculate shift bits */
+#define NN_SHIFT(pos) ((pos) % NN_ITEM_PER_VAR) * NN_BITS_PER_MEMBER
/*
* initialize_windowaggregate
@@ -942,7 +979,8 @@ eval_windowaggregates(WindowAggState *winstate)
* Exit loop if no more rows can be in frame. Skip aggregation if
* current row is not in frame but there might be more in the frame.
*/
- ret = row_is_in_frame(winstate, winstate->aggregatedupto, agg_row_slot);
+ ret = row_is_in_frame(agg_winobj, winstate->aggregatedupto,
+ agg_row_slot, false);
if (ret < 0)
break;
if (ret == 0)
@@ -1263,6 +1301,12 @@ begin_partition(WindowAggState *winstate)
winobj->markpos = -1;
winobj->seekpos = -1;
+
+ /* reset null map */
+ if (winobj->ignore_nulls == IGNORE_NULLS)
+ memset(winobj->notnull_info, 0,
+ NN_POS_TO_BYTES(
+ perfuncstate->winobj->num_notnull_info));
}
}
@@ -1412,8 +1456,8 @@ release_partition(WindowAggState *winstate)
* to our window framing rule
*
* The caller must have already determined that the row is in the partition
- * and fetched it into a slot. This function just encapsulates the framing
- * rules.
+ * and fetched it into a slot if fetch_tuple is false.
+.* This function just encapsulates the framing rules.
*
* Returns:
* -1, if the row is out of frame and no succeeding rows can be in frame
@@ -1423,8 +1467,10 @@ release_partition(WindowAggState *winstate)
* May clobber winstate->temp_slot_2.
*/
static int
-row_is_in_frame(WindowAggState *winstate, int64 pos, TupleTableSlot *slot)
+row_is_in_frame(WindowObject winobj, int64 pos, TupleTableSlot *slot,
+ bool fetch_tuple)
{
+ WindowAggState *winstate = winobj->winstate;
int frameOptions = winstate->frameOptions;
Assert(pos >= 0); /* else caller error */
@@ -1453,9 +1499,13 @@ row_is_in_frame(WindowAggState *winstate, int64 pos, TupleTableSlot *slot)
else if (frameOptions & (FRAMEOPTION_RANGE | FRAMEOPTION_GROUPS))
{
/* following row that is not peer is out of frame */
- if (pos > winstate->currentpos &&
- !are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot))
- return -1;
+ if (pos > winstate->currentpos)
+ {
+ if (fetch_tuple)
+ window_gettupleslot(winobj, pos, slot);
+ if (!are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot))
+ return -1;
+ }
}
else
Assert(false);
@@ -2619,14 +2669,17 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
elog(ERROR, "WindowFunc with winref %u assigned to WindowAgg with winref %u",
wfunc->winref, node->winref);
- /* Look for a previous duplicate window function */
+ /*
+ * Look for a previous duplicate window function, which needs the same
+ * ignore_nulls value
+ */
for (i = 0; i <= wfuncno; i++)
{
if (equal(wfunc, perfunc[i].wfunc) &&
!contain_volatile_functions((Node *) wfunc))
break;
}
- if (i <= wfuncno)
+ if (i <= wfuncno && wfunc->ignore_nulls == perfunc[i].ignore_nulls)
{
/* Found a match to an existing entry, so just mark it */
wfuncstate->wfuncno = i;
@@ -2679,6 +2732,8 @@ ExecInitWindowAgg(WindowAgg *node, EState *estate, int eflags)
winobj->argstates = wfuncstate->args;
winobj->localmem = NULL;
perfuncstate->winobj = winobj;
+ winobj->ignore_nulls = wfunc->ignore_nulls;
+ init_notnull_info(winobj);
/* It's a real window function, so set up to call it. */
fmgr_info_cxt(wfunc->winfnoid, &perfuncstate->flinfo,
@@ -3214,12 +3269,294 @@ window_gettupleslot(WindowObject winobj, int64 pos, TupleTableSlot *slot)
return true;
}
+/*
+ * get tupple and evaluate in a partition
+ */
+static Datum
+gettuple_eval_partition(WindowObject winobj, int argno,
+ int64 abs_pos, bool *isnull, bool *isout)
+{
+ WindowAggState *winstate;
+ ExprContext *econtext;
+ TupleTableSlot *slot;
+
+ winstate = winobj->winstate;
+ slot = winstate->temp_slot_1;
+ if (!window_gettupleslot(winobj, abs_pos, slot))
+ {
+ /* out of partition */
+ if (isout)
+ *isout = true;
+ *isnull = true;
+ return (Datum) 0;
+ }
+
+ if (isout)
+ *isout = false;
+ econtext = winstate->ss.ps.ps_ExprContext;
+ econtext->ecxt_outertuple = slot;
+ return ExecEvalExpr((ExprState *) list_nth
+ (winobj->argstates, argno),
+ econtext, isnull);
+}
+
+/*
+ * ignorenulls_getfuncarginframe
+ * For IGNORE NULLS, get the next nonnull value in the frame, moving forward
+ * or backward until we find a value or reach the frame's end.
+ */
+static Datum
+ignorenulls_getfuncarginframe(WindowObject winobj, int argno,
+ int relpos, int seektype, bool set_mark,
+ bool *isnull, bool *isout)
+{
+ WindowAggState *winstate;
+ ExprContext *econtext;
+ TupleTableSlot *slot;
+ Datum datum;
+ int64 abs_pos;
+ int64 mark_pos;
+ int notnull_offset;
+ int notnull_relpos;
+ int forward;
+
+ Assert(WindowObjectIsValid(winobj));
+ winstate = winobj->winstate;
+ econtext = winstate->ss.ps.ps_ExprContext;
+ slot = winstate->temp_slot_1;
+ datum = (Datum) 0;
+ notnull_offset = 0;
+ notnull_relpos = abs(relpos);
+
+ switch (seektype)
+ {
+ case WINDOW_SEEK_CURRENT:
+ elog(ERROR, "WINDOW_SEEK_CURRENT is not supported for WinGetFuncArgInFrame");
+ abs_pos = mark_pos = 0; /* keep compiler quiet */
+ break;
+ case WINDOW_SEEK_HEAD:
+ /* rejecting relpos < 0 is easy and simplifies code below */
+ if (relpos < 0)
+ goto out_of_frame;
+ update_frameheadpos(winstate);
+ abs_pos = winstate->frameheadpos;
+ mark_pos = winstate->frameheadpos;
+ forward = 1;
+ break;
+ case WINDOW_SEEK_TAIL:
+ /* rejecting relpos > 0 is easy and simplifies code below */
+ if (relpos > 0)
+ goto out_of_frame;
+ update_frametailpos(winstate);
+ abs_pos = winstate->frametailpos - 1;
+ mark_pos = 0; /* keep compiler quiet */
+ forward = -1;
+ break;
+ default:
+ elog(ERROR, "unrecognized window seek type: %d", seektype);
+ abs_pos = mark_pos = 0; /* keep compiler quiet */
+ break;
+ }
+
+ /*
+ * Get the next nonnull value in the frame, moving forward or backward
+ * until we find a value or reach the frame's end.
+ */
+ do
+ {
+ int inframe;
+ int v;
+
+ /*
+ * Check apparent out of frame case. We need to do this because we
+ * may not call window_gettupleslot before row_is_in_frame, which
+ * supposes abs_pos is never negative.
+ */
+ if (abs_pos < 0)
+ goto out_of_frame;
+
+ /* check whether row is in frame */
+ inframe = row_is_in_frame(winobj, abs_pos, slot, true);
+ if (inframe == -1)
+ goto out_of_frame;
+ else if (inframe == 0)
+ goto advance;
+
+ if (isout)
+ *isout = false;
+
+ v = get_notnull_info(winobj, abs_pos);
+ if (v == NN_NULL) /* this row is known to be NULL */
+ goto advance;
+
+ else if (v == NN_UNKNOWN) /* need to check NULL or not */
+ {
+ if (!window_gettupleslot(winobj, abs_pos, slot))
+ goto out_of_frame;
+
+ econtext->ecxt_outertuple = slot;
+ datum = ExecEvalExpr(
+ (ExprState *) list_nth(winobj->argstates,
+ argno), econtext,
+ isnull);
+ if (!*isnull)
+ notnull_offset++;
+
+ /* record the row status */
+ put_notnull_info(winobj, abs_pos, *isnull);
+ }
+ else /* this row is known to be NOT NULL */
+ {
+ notnull_offset++;
+ if (notnull_offset > notnull_relpos)
+ {
+ /* to prepare exiting this loop, datum needs to be set */
+ if (!window_gettupleslot(winobj, abs_pos, slot))
+ goto out_of_frame;
+
+ econtext->ecxt_outertuple = slot;
+ datum = ExecEvalExpr(
+ (ExprState *) list_nth
+ (winobj->argstates, argno),
+ econtext, isnull);
+ }
+ }
+advance:
+ abs_pos += forward;
+ } while (notnull_offset <= notnull_relpos);
+
+ if (set_mark)
+ WinSetMarkPosition(winobj, mark_pos);
+
+ return datum;
+
+out_of_frame:
+ if (isout)
+ *isout = true;
+ *isnull = true;
+ return (Datum) 0;
+}
+
+
+/*
+ * init_notnull_info
+ * Initialize non null map.
+ */
+static void
+init_notnull_info(WindowObject winobj)
+{
+/* initial number of notnull info members */
+#define INIT_NOT_NULL_INFO_NUM 128
+
+ if (winobj->ignore_nulls == PARSER_IGNORE_NULLS)
+ {
+ Size size = NN_POS_TO_BYTES(INIT_NOT_NULL_INFO_NUM);
+
+ winobj->notnull_info = palloc0(size);
+ winobj->num_notnull_info = INIT_NOT_NULL_INFO_NUM;
+ }
+}
+
+/*
+ * grow_notnull_info
+ * expand notnull_info if necessary.
+ * pos: not null info position
+*/
+static void
+grow_notnull_info(WindowObject winobj, int64 pos)
+{
+ if (pos >= winobj->num_notnull_info)
+ {
+ for (;;)
+ {
+ Size oldsize = NN_POS_TO_BYTES(winobj->num_notnull_info);
+ Size newsize = oldsize * 2;
+
+ winobj->notnull_info =
+ repalloc0(winobj->notnull_info, oldsize, newsize);
+ winobj->num_notnull_info = NN_BYTES_TO_POS(newsize);
+ if (winobj->num_notnull_info > pos)
+ break;
+ }
+ }
+}
+
+/*
+ * get_notnull_info
+ * retrieve a map
+ * pos: map position
+ */
+static uint8
+get_notnull_info(WindowObject winobj, int64 pos)
+{
+ uint8 mb;
+ int64 bpos;
+
+ grow_notnull_info(winobj, pos);
+ bpos = NN_POS_TO_BYTES(pos);
+ mb = winobj->notnull_info[bpos];
+ return (mb >> (NN_SHIFT(pos))) & NN_MASK;
+}
+
+/*
+ * put_notnull_info
+ * update map
+ * pos: map position
+ */
+static void
+put_notnull_info(WindowObject winobj, int64 pos, bool isnull)
+{
+ uint8 mb;
+ int64 bpos;
+ uint8 val = isnull ? NN_NULL : NN_NOTNULL;
+ int shift;
+
+ grow_notnull_info(winobj, pos);
+ bpos = NN_POS_TO_BYTES(pos);
+ mb = winobj->notnull_info[bpos];
+ shift = NN_SHIFT(pos);
+ mb &= ~(NN_MASK << shift); /* clear map */
+ mb |= (val << shift); /* update map */
+ winobj->notnull_info[bpos] = mb;
+}
/***********************************************************************
* API exposed to window functions
***********************************************************************/
+/*
+ * WinCheckAndInitializeNullTreatment
+ * Check null treatment clause and sets ignore_nulls
+ *
+ * Window functions should call this to check if they are being called with
+ * a null treatment clause when they don't allow it, or to set ignore_nulls.
+ */
+void
+WinCheckAndInitializeNullTreatment(WindowObject winobj,
+ bool allowNullTreatment,
+ FunctionCallInfo fcinfo)
+{
+ if (winobj->ignore_nulls != NO_NULLTREATMENT && !allowNullTreatment)
+ {
+ HeapTuple proctup;
+ Form_pg_proc procform;
+ Oid funcid;
+
+ funcid = fcinfo->flinfo->fn_oid;
+ proctup = SearchSysCache1(PROCOID,
+ ObjectIdGetDatum(funcid));
+ if (!HeapTupleIsValid(proctup))
+ elog(ERROR, "cache lookup failed for function %u", funcid);
+ procform = (Form_pg_proc) GETSTRUCT(proctup);
+ elog(ERROR, "function %s does not allow RESPECT/IGNORE NULLS",
+ NameStr(procform->proname));
+ }
+ else if (winobj->ignore_nulls == PARSER_IGNORE_NULLS)
+ winobj->ignore_nulls = IGNORE_NULLS;
+
+}
+
/*
* WinGetPartitionLocalMemory
* Get working memory that lives till end of partition processing
@@ -3378,23 +3715,37 @@ WinGetFuncArgInPartition(WindowObject winobj, int argno,
bool *isnull, bool *isout)
{
WindowAggState *winstate;
- ExprContext *econtext;
- TupleTableSlot *slot;
- bool gottuple;
int64 abs_pos;
+ Datum datum;
+ bool null_treatment = false;
+ int notnull_offset;
+ int notnull_relpos;
+ int forward;
Assert(WindowObjectIsValid(winobj));
winstate = winobj->winstate;
- econtext = winstate->ss.ps.ps_ExprContext;
- slot = winstate->temp_slot_1;
+
+ if (winobj->ignore_nulls == IGNORE_NULLS && relpos != 0)
+ {
+ null_treatment = true;
+ notnull_offset = 0;
+ notnull_relpos = abs(relpos);
+ forward = relpos > 0 ? 1 : -1;
+ }
switch (seektype)
{
case WINDOW_SEEK_CURRENT:
- abs_pos = winstate->currentpos + relpos;
+ if (null_treatment)
+ abs_pos = winstate->currentpos;
+ else
+ abs_pos = winstate->currentpos + relpos;
break;
case WINDOW_SEEK_HEAD:
- abs_pos = relpos;
+ if (null_treatment)
+ abs_pos = 0;
+ else
+ abs_pos = relpos;
break;
case WINDOW_SEEK_TAIL:
spool_tuples(winstate, -1);
@@ -3406,25 +3757,67 @@ WinGetFuncArgInPartition(WindowObject winobj, int argno,
break;
}
- gottuple = window_gettupleslot(winobj, abs_pos, slot);
-
- if (!gottuple)
- {
- if (isout)
- *isout = true;
- *isnull = true;
- return (Datum) 0;
- }
- else
+ if (!null_treatment) /* IGNORE NULLS is not specified */
{
- if (isout)
- *isout = false;
- if (set_mark)
+ datum = gettuple_eval_partition(winobj, argno,
+ abs_pos, isnull, isout);
+ if (!*isout && set_mark)
WinSetMarkPosition(winobj, abs_pos);
- econtext->ecxt_outertuple = slot;
- return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
- econtext, isnull);
+ return datum;
}
+
+ /*
+ * Get the next nonnull value in the partition, moving forward or backward
+ * until we find a value or reach the partition's end.
+ */
+ do
+ {
+ abs_pos += forward;
+ if (abs_pos < 0)
+ {
+ /* out of partition */
+ if (isout)
+ *isout = true;
+ *isnull = true;
+ datum = 0;
+ break;
+ }
+
+ switch (get_notnull_info(winobj, abs_pos))
+ {
+ case NN_NOTNULL: /* this row is known to be NOT NULL */
+ notnull_offset++;
+ if (notnull_offset >= notnull_relpos)
+ {
+ /* prepare to exit this loop */
+ datum = gettuple_eval_partition(winobj, argno,
+ abs_pos, isnull, isout);
+ }
+ break;
+ case NN_NULL: /* this row is known to be NULL */
+ if (isout)
+ *isout = false;
+ *isnull = true;
+ datum = 0;
+ break;
+ default: /* need to check NULL or not */
+ datum = gettuple_eval_partition(winobj, argno,
+ abs_pos, isnull, isout);
+ if (*isout) /* out of partition? */
+ return datum;
+
+ if (!*isnull)
+ notnull_offset++;
+ /* record the row status */
+ put_notnull_info(winobj, abs_pos, *isnull);
+ break;
+ }
+ } while (notnull_offset < notnull_relpos);
+
+ if (!*isout && set_mark)
+ WinSetMarkPosition(winobj, abs_pos);
+
+ return datum;
}
/*
@@ -3476,6 +3869,10 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno,
econtext = winstate->ss.ps.ps_ExprContext;
slot = winstate->temp_slot_1;
+ if (winobj->ignore_nulls == IGNORE_NULLS)
+ return ignorenulls_getfuncarginframe(winobj, argno, relpos, seektype,
+ set_mark, isnull, isout);
+
switch (seektype)
{
case WINDOW_SEEK_CURRENT:
@@ -3624,7 +4021,7 @@ WinGetFuncArgInFrame(WindowObject winobj, int argno,
goto out_of_frame;
/* The code above does not detect all out-of-frame cases, so check */
- if (row_is_in_frame(winstate, abs_pos, slot) <= 0)
+ if (row_is_in_frame(winobj, abs_pos, slot, false) <= 0)
goto out_of_frame;
if (isout)
diff --git a/src/backend/utils/adt/windowfuncs.c b/src/backend/utils/adt/windowfuncs.c
index bb35f3bc4a9..969f02aa59b 100644
--- a/src/backend/utils/adt/windowfuncs.c
+++ b/src/backend/utils/adt/windowfuncs.c
@@ -86,6 +86,7 @@ window_row_number(PG_FUNCTION_ARGS)
WindowObject winobj = PG_WINDOW_OBJECT();
int64 curpos = WinGetCurrentPosition(winobj);
+ WinCheckAndInitializeNullTreatment(winobj, false, fcinfo);
WinSetMarkPosition(winobj, curpos);
PG_RETURN_INT64(curpos + 1);
}
@@ -141,6 +142,7 @@ window_rank(PG_FUNCTION_ARGS)
rank_context *context;
bool up;
+ WinCheckAndInitializeNullTreatment(winobj, false, fcinfo);
up = rank_up(winobj);
context = (rank_context *)
WinGetPartitionLocalMemory(winobj, sizeof(rank_context));
@@ -203,6 +205,7 @@ window_dense_rank(PG_FUNCTION_ARGS)
rank_context *context;
bool up;
+ WinCheckAndInitializeNullTreatment(winobj, false, fcinfo);
up = rank_up(winobj);
context = (rank_context *)
WinGetPartitionLocalMemory(winobj, sizeof(rank_context));
@@ -266,6 +269,7 @@ window_percent_rank(PG_FUNCTION_ARGS)
int64 totalrows = WinGetPartitionRowCount(winobj);
Assert(totalrows > 0);
+ WinCheckAndInitializeNullTreatment(winobj, false, fcinfo);
up = rank_up(winobj);
context = (rank_context *)
@@ -335,6 +339,7 @@ window_cume_dist(PG_FUNCTION_ARGS)
int64 totalrows = WinGetPartitionRowCount(winobj);
Assert(totalrows > 0);
+ WinCheckAndInitializeNullTreatment(winobj, false, fcinfo);
up = rank_up(winobj);
context = (rank_context *)
@@ -413,6 +418,7 @@ window_ntile(PG_FUNCTION_ARGS)
WindowObject winobj = PG_WINDOW_OBJECT();
ntile_context *context;
+ WinCheckAndInitializeNullTreatment(winobj, false, fcinfo);
context = (ntile_context *)
WinGetPartitionLocalMemory(winobj, sizeof(ntile_context));
@@ -535,6 +541,7 @@ leadlag_common(FunctionCallInfo fcinfo,
bool isnull;
bool isout;
+ WinCheckAndInitializeNullTreatment(winobj, true, fcinfo);
if (withoffset)
{
offset = DatumGetInt32(WinGetFuncArgCurrent(winobj, 1, &isnull));
@@ -652,6 +659,7 @@ window_first_value(PG_FUNCTION_ARGS)
Datum result;
bool isnull;
+ WinCheckAndInitializeNullTreatment(winobj, true, fcinfo);
result = WinGetFuncArgInFrame(winobj, 0,
0, WINDOW_SEEK_HEAD, true,
&isnull, NULL);
@@ -673,6 +681,7 @@ window_last_value(PG_FUNCTION_ARGS)
Datum result;
bool isnull;
+ WinCheckAndInitializeNullTreatment(winobj, true, fcinfo);
result = WinGetFuncArgInFrame(winobj, 0,
0, WINDOW_SEEK_TAIL, true,
&isnull, NULL);
@@ -696,6 +705,7 @@ window_nth_value(PG_FUNCTION_ARGS)
bool isnull;
int32 nth;
+ WinCheckAndInitializeNullTreatment(winobj, true, fcinfo);
nth = DatumGetInt32(WinGetFuncArgCurrent(winobj, 1, &isnull));
if (isnull)
PG_RETURN_NULL();
diff --git a/src/include/windowapi.h b/src/include/windowapi.h
index cb2ece166b6..20cfd9e9dd9 100644
--- a/src/include/windowapi.h
+++ b/src/include/windowapi.h
@@ -28,6 +28,8 @@
#ifndef WINDOWAPI_H
#define WINDOWAPI_H
+#include "fmgr.h"
+
/* values of "seektype" */
#define WINDOW_SEEK_CURRENT 0
#define WINDOW_SEEK_HEAD 1
@@ -41,6 +43,10 @@ typedef struct WindowObjectData *WindowObject;
#define WindowObjectIsValid(winobj) \
((winobj) != NULL && IsA(winobj, WindowObjectData))
+extern void WinCheckAndInitializeNullTreatment(WindowObject winobj,
+ bool allowNullTreatment,
+ FunctionCallInfo fcinfo);
+
extern void *WinGetPartitionLocalMemory(WindowObject winobj, Size sz);
extern int64 WinGetCurrentPosition(WindowObject winobj);
--
2.43.0
[application/octet-stream] v20-0005-Modify-documents-to-add-null-treatment-clause.patch (4.9K, ../[email protected]/6-v20-0005-Modify-documents-to-add-null-treatment-clause.patch)
download | inline diff:
From 112f9cd77e5fdcd78692d12b101dd5b46ea05d84 Mon Sep 17 00:00:00 2001
From: Tatsuo Ishii <[email protected]>
Date: Thu, 2 Oct 2025 21:06:40 +0900
Subject: [PATCH v20 5/6] Modify documents to add null treatment clause.
---
doc/src/sgml/func/func-window.sgml | 38 ++++++++++++++++++------------
1 file changed, 23 insertions(+), 15 deletions(-)
diff --git a/doc/src/sgml/func/func-window.sgml b/doc/src/sgml/func/func-window.sgml
index cce0165b952..bcf755c9ebc 100644
--- a/doc/src/sgml/func/func-window.sgml
+++ b/doc/src/sgml/func/func-window.sgml
@@ -140,7 +140,7 @@
</indexterm>
<function>lag</function> ( <parameter>value</parameter> <type>anycompatible</type>
<optional>, <parameter>offset</parameter> <type>integer</type>
- <optional>, <parameter>default</parameter> <type>anycompatible</type> </optional></optional> )
+ <optional>, <parameter>default</parameter> <type>anycompatible</type> </optional></optional> ) <optional> <parameter>null treatment</parameter> </optional>
<returnvalue>anycompatible</returnvalue>
</para>
<para>
@@ -165,7 +165,7 @@
</indexterm>
<function>lead</function> ( <parameter>value</parameter> <type>anycompatible</type>
<optional>, <parameter>offset</parameter> <type>integer</type>
- <optional>, <parameter>default</parameter> <type>anycompatible</type> </optional></optional> )
+ <optional>, <parameter>default</parameter> <type>anycompatible</type> </optional></optional> ) <optional> <parameter>null treatment</parameter> </optional>
<returnvalue>anycompatible</returnvalue>
</para>
<para>
@@ -188,7 +188,7 @@
<indexterm>
<primary>first_value</primary>
</indexterm>
- <function>first_value</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <function>first_value</function> ( <parameter>value</parameter> <type>anyelement</type> ) <optional> <parameter>null treatment</parameter> </optional>
<returnvalue>anyelement</returnvalue>
</para>
<para>
@@ -202,7 +202,7 @@
<indexterm>
<primary>last_value</primary>
</indexterm>
- <function>last_value</function> ( <parameter>value</parameter> <type>anyelement</type> )
+ <function>last_value</function> ( <parameter>value</parameter> <type>anyelement</type> ) <optional> <parameter>null treatment</parameter> </optional>
<returnvalue>anyelement</returnvalue>
</para>
<para>
@@ -216,7 +216,7 @@
<indexterm>
<primary>nth_value</primary>
</indexterm>
- <function>nth_value</function> ( <parameter>value</parameter> <type>anyelement</type>, <parameter>n</parameter> <type>integer</type> )
+ <function>nth_value</function> ( <parameter>value</parameter> <type>anyelement</type>, <parameter>n</parameter> <type>integer</type> ) <optional> <parameter>null treatment</parameter> </optional>
<returnvalue>anyelement</returnvalue>
</para>
<para>
@@ -265,18 +265,26 @@
Other frame specifications can be used to obtain other effects.
</para>
+ <para>
+ The <literal>null treatment</literal> option must be one of:
+<synopsis>
+ RESPECT NULLS
+ IGNORE NULLS
+</synopsis>
+ If unspecified, the default is <literal>RESPECT NULLS</literal> which includes NULL
+ values in any result calculation. <literal>IGNORE NULLS</literal> ignores NULL values.
+ This option is only allowed for the following functions: <function>lag</function>,
+ <function>lead</function>, <function>first_value</function>, <function>last_value</function>,
+ <function>nth_value</function>.
+ </para>
+
<note>
<para>
- The SQL standard defines a <literal>RESPECT NULLS</literal> or
- <literal>IGNORE NULLS</literal> option for <function>lead</function>, <function>lag</function>,
- <function>first_value</function>, <function>last_value</function>, and
- <function>nth_value</function>. This is not implemented in
- <productname>PostgreSQL</productname>: the behavior is always the
- same as the standard's default, namely <literal>RESPECT NULLS</literal>.
- Likewise, the standard's <literal>FROM FIRST</literal> or <literal>FROM LAST</literal>
- option for <function>nth_value</function> is not implemented: only the
- default <literal>FROM FIRST</literal> behavior is supported. (You can achieve
- the result of <literal>FROM LAST</literal> by reversing the <literal>ORDER BY</literal>
+ The SQL standard defines a <literal>FROM FIRST</literal> or <literal>FROM LAST</literal>
+ option for <function>nth_value</function>. This is not implemented in
+ <productname>PostgreSQL</productname>: only the default <literal>FROM FIRST</literal>
+ behavior is supported. (You can achieve the result of <literal>FROM LAST</literal> by
+ reversing the <literal>ORDER BY</literal>
ordering.)
</para>
</note>
--
2.43.0
[application/octet-stream] v20-0006-Modify-window-function-regression-tests-to-test-.patch (21.4K, ../[email protected]/7-v20-0006-Modify-window-function-regression-tests-to-test-.patch)
download | inline diff:
From 041e95f6b11f4c9cfcd88480621aa70b8d1d753e Mon Sep 17 00:00:00 2001
From: Tatsuo Ishii <[email protected]>
Date: Thu, 2 Oct 2025 21:06:40 +0900
Subject: [PATCH v20 6/6] Modify window function regression tests to test null
treatment clause.
---
src/test/regress/expected/window.out | 406 +++++++++++++++++++++++++++
src/test/regress/sql/window.sql | 162 +++++++++++
2 files changed, 568 insertions(+)
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index b86b668f433..a595fa28ce1 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -5453,3 +5453,409 @@ SELECT * FROM pg_temp.f(2);
{5}
(5 rows)
+-- IGNORE NULLS tests
+CREATE TEMPORARY TABLE planets (
+ name text,
+ distance text,
+ orbit integer
+);
+INSERT INTO planets VALUES
+ ('mercury', 'close', 88),
+ ('venus', 'close', 224),
+ ('earth', 'close', NULL),
+ ('mars', 'close', NULL),
+ ('jupiter', 'close', 4332),
+ ('saturn', 'far', 24491),
+ ('uranus', 'far', NULL),
+ ('neptune', 'far', 60182),
+ ('pluto', 'far', 90560),
+ ('xyzzy', 'far', NULL);
+-- test ruleutils
+CREATE VIEW planets_view AS
+SELECT name,
+ orbit,
+ lag(orbit) OVER w AS lag,
+ lag(orbit) RESPECT NULLS OVER w AS lag_respect,
+ lag(orbit) IGNORE NULLS OVER w AS lag_ignore
+FROM planets
+WINDOW w AS (ORDER BY name)
+;
+NOTICE: view "planets_view" will be a temporary view
+SELECT pg_get_viewdef('planets_view');
+ pg_get_viewdef
+--------------------------------------------------
+ SELECT name, +
+ orbit, +
+ lag(orbit) OVER w AS lag, +
+ lag(orbit) OVER w AS lag_respect, +
+ lag(orbit) IGNORE NULLS OVER w AS lag_ignore+
+ FROM planets +
+ WINDOW w AS (ORDER BY name);
+(1 row)
+
+-- lag
+SELECT name,
+ orbit,
+ lag(orbit) OVER w AS lag,
+ lag(orbit) RESPECT NULLS OVER w AS lag_respect,
+ lag(orbit) IGNORE NULLS OVER w AS lag_ignore
+FROM planets
+WINDOW w AS (ORDER BY name)
+;
+ name | orbit | lag | lag_respect | lag_ignore
+---------+-------+-------+-------------+------------
+ earth | | | |
+ jupiter | 4332 | | |
+ mars | | 4332 | 4332 | 4332
+ mercury | 88 | | | 4332
+ neptune | 60182 | 88 | 88 | 88
+ pluto | 90560 | 60182 | 60182 | 60182
+ saturn | 24491 | 90560 | 90560 | 90560
+ uranus | | 24491 | 24491 | 24491
+ venus | 224 | | | 24491
+ xyzzy | | 224 | 224 | 224
+(10 rows)
+
+-- lead
+SELECT name,
+ orbit,
+ lead(orbit) OVER w AS lead,
+ lead(orbit) RESPECT NULLS OVER w AS lead_respect,
+ lead(orbit) IGNORE NULLS OVER w AS lead_ignore
+FROM planets
+WINDOW w AS (ORDER BY name)
+;
+ name | orbit | lead | lead_respect | lead_ignore
+---------+-------+-------+--------------+-------------
+ earth | | 4332 | 4332 | 4332
+ jupiter | 4332 | | | 88
+ mars | | 88 | 88 | 88
+ mercury | 88 | 60182 | 60182 | 60182
+ neptune | 60182 | 90560 | 90560 | 90560
+ pluto | 90560 | 24491 | 24491 | 24491
+ saturn | 24491 | | | 224
+ uranus | | 224 | 224 | 224
+ venus | 224 | | |
+ xyzzy | | | |
+(10 rows)
+
+-- first_value
+SELECT name,
+ orbit,
+ first_value(orbit) RESPECT NULLS OVER w1,
+ first_value(orbit) IGNORE NULLS OVER w1,
+ first_value(orbit) RESPECT NULLS OVER w2,
+ first_value(orbit) IGNORE NULLS OVER w2
+FROM planets
+WINDOW w1 AS (ORDER BY name ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING),
+ w2 AS (ORDER BY name ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING)
+;
+ name | orbit | first_value | first_value | first_value | first_value
+---------+-------+-------------+-------------+-------------+-------------
+ earth | | | 4332 | | 4332
+ jupiter | 4332 | | 4332 | | 4332
+ mars | | | 4332 | | 4332
+ mercury | 88 | | 4332 | 4332 | 4332
+ neptune | 60182 | | 4332 | | 88
+ pluto | 90560 | | 4332 | 88 | 88
+ saturn | 24491 | | 4332 | 60182 | 60182
+ uranus | | | 4332 | 90560 | 90560
+ venus | 224 | | 4332 | 24491 | 24491
+ xyzzy | | | 4332 | | 224
+(10 rows)
+
+-- nth_value
+SELECT name,
+ orbit,
+ nth_value(orbit, 2) RESPECT NULLS OVER w1,
+ nth_value(orbit, 2) IGNORE NULLS OVER w1,
+ nth_value(orbit, 2) RESPECT NULLS OVER w2,
+ nth_value(orbit, 2) IGNORE NULLS OVER w2
+FROM planets
+WINDOW w1 AS (ORDER BY name ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING),
+ w2 AS (ORDER BY name ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING)
+;
+ name | orbit | nth_value | nth_value | nth_value | nth_value
+---------+-------+-----------+-----------+-----------+-----------
+ earth | | 4332 | 88 | 4332 |
+ jupiter | 4332 | 4332 | 88 | 4332 | 88
+ mars | | 4332 | 88 | 4332 | 88
+ mercury | 88 | 4332 | 88 | | 88
+ neptune | 60182 | 4332 | 88 | 88 | 60182
+ pluto | 90560 | 4332 | 88 | 60182 | 60182
+ saturn | 24491 | 4332 | 88 | 90560 | 90560
+ uranus | | 4332 | 88 | 24491 | 24491
+ venus | 224 | 4332 | 88 | | 224
+ xyzzy | | 4332 | 88 | 224 |
+(10 rows)
+
+-- last_value
+SELECT name,
+ orbit,
+ last_value(orbit) RESPECT NULLS OVER w1,
+ last_value(orbit) IGNORE NULLS OVER w1,
+ last_value(orbit) RESPECT NULLS OVER w2,
+ last_value(orbit) IGNORE NULLS OVER w2
+FROM planets
+WINDOW w1 AS (ORDER BY name ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING),
+ w2 AS (ORDER BY name ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING)
+;
+ name | orbit | last_value | last_value | last_value | last_value
+---------+-------+------------+------------+------------+------------
+ earth | | | 224 | | 4332
+ jupiter | 4332 | | 224 | 88 | 88
+ mars | | | 224 | 60182 | 60182
+ mercury | 88 | | 224 | 90560 | 90560
+ neptune | 60182 | | 224 | 24491 | 24491
+ pluto | 90560 | | 224 | | 24491
+ saturn | 24491 | | 224 | 224 | 224
+ uranus | | | 224 | | 224
+ venus | 224 | | 224 | | 224
+ xyzzy | | | 224 | | 224
+(10 rows)
+
+-- exclude current row
+SELECT name,
+ orbit,
+ first_value(orbit) IGNORE NULLS OVER w,
+ last_value(orbit) IGNORE NULLS OVER w,
+ nth_value(orbit, 2) IGNORE NULLS OVER w,
+ lead(orbit, 1) IGNORE NULLS OVER w AS lead_ignore,
+ lag(orbit, 1) IGNORE NULLS OVER w AS lag_ignore
+FROM planets
+WINDOW w AS (ORDER BY name ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING EXCLUDE CURRENT ROW)
+;
+ name | orbit | first_value | last_value | nth_value | lead_ignore | lag_ignore
+---------+-------+-------------+------------+-----------+-------------+------------
+ earth | | 4332 | 4332 | | 4332 |
+ jupiter | 4332 | 88 | 88 | | 88 |
+ mars | | 4332 | 60182 | 88 | 88 | 4332
+ mercury | 88 | 4332 | 90560 | 60182 | 60182 | 4332
+ neptune | 60182 | 88 | 24491 | 90560 | 90560 | 88
+ pluto | 90560 | 88 | 24491 | 60182 | 24491 | 60182
+ saturn | 24491 | 60182 | 224 | 90560 | 224 | 90560
+ uranus | | 90560 | 224 | 24491 | 224 | 24491
+ venus | 224 | 24491 | 24491 | | | 24491
+ xyzzy | | 224 | 224 | | | 224
+(10 rows)
+
+-- valid and invalid functions
+SELECT sum(orbit) OVER () FROM planets; -- succeeds
+ sum
+--------
+ 179877
+ 179877
+ 179877
+ 179877
+ 179877
+ 179877
+ 179877
+ 179877
+ 179877
+ 179877
+(10 rows)
+
+SELECT sum(orbit) RESPECT NULLS OVER () FROM planets; -- fails
+ERROR: aggregate functions do not accept RESPECT/IGNORE NULLS
+LINE 1: SELECT sum(orbit) RESPECT NULLS OVER () FROM planets;
+ ^
+SELECT sum(orbit) IGNORE NULLS OVER () FROM planets; -- fails
+ERROR: aggregate functions do not accept RESPECT/IGNORE NULLS
+LINE 1: SELECT sum(orbit) IGNORE NULLS OVER () FROM planets;
+ ^
+SELECT row_number() OVER () FROM planets; -- succeeds
+ row_number
+------------
+ 1
+ 2
+ 3
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+ 10
+(10 rows)
+
+SELECT row_number() RESPECT NULLS OVER () FROM planets; -- fails
+ERROR: function row_number does not allow RESPECT/IGNORE NULLS
+SELECT row_number() IGNORE NULLS OVER () FROM planets; -- fails
+ERROR: function row_number does not allow RESPECT/IGNORE NULLS
+SELECT rank() OVER () FROM planets; -- succeeds
+ rank
+------
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+(10 rows)
+
+SELECT rank() RESPECT NULLS OVER () FROM planets; -- fails
+ERROR: function rank does not allow RESPECT/IGNORE NULLS
+SELECT rank() IGNORE NULLS OVER () FROM planets; -- fails
+ERROR: function rank does not allow RESPECT/IGNORE NULLS
+SELECT dense_rank() OVER () FROM planets; -- succeeds
+ dense_rank
+------------
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+(10 rows)
+
+SELECT dense_rank() RESPECT NULLS OVER () FROM planets; -- fails
+ERROR: function dense_rank does not allow RESPECT/IGNORE NULLS
+SELECT dense_rank() IGNORE NULLS OVER () FROM planets; -- fails
+ERROR: function dense_rank does not allow RESPECT/IGNORE NULLS
+SELECT percent_rank() OVER () FROM planets; -- succeeds
+ percent_rank
+--------------
+ 0
+ 0
+ 0
+ 0
+ 0
+ 0
+ 0
+ 0
+ 0
+ 0
+(10 rows)
+
+SELECT percent_rank() RESPECT NULLS OVER () FROM planets; -- fails
+ERROR: function percent_rank does not allow RESPECT/IGNORE NULLS
+SELECT percent_rank() IGNORE NULLS OVER () FROM planets; -- fails
+ERROR: function percent_rank does not allow RESPECT/IGNORE NULLS
+SELECT cume_dist() OVER () FROM planets; -- succeeds
+ cume_dist
+-----------
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+(10 rows)
+
+SELECT cume_dist() RESPECT NULLS OVER () FROM planets; -- fails
+ERROR: function cume_dist does not allow RESPECT/IGNORE NULLS
+SELECT cume_dist() IGNORE NULLS OVER () FROM planets; -- fails
+ERROR: function cume_dist does not allow RESPECT/IGNORE NULLS
+SELECT ntile(1) OVER () FROM planets; -- succeeds
+ ntile
+-------
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+ 1
+(10 rows)
+
+SELECT ntile(1) RESPECT NULLS OVER () FROM planets; -- fails
+ERROR: function ntile does not allow RESPECT/IGNORE NULLS
+SELECT ntile(1) IGNORE NULLS OVER () FROM planets; -- fails
+ERROR: function ntile does not allow RESPECT/IGNORE NULLS
+-- test two consecutive nulls
+update planets set orbit=null where name='jupiter';
+SELECT name,
+ orbit,
+ first_value(orbit) IGNORE NULLS OVER w,
+ last_value(orbit) IGNORE NULLS OVER w,
+ nth_value(orbit, 2) IGNORE NULLS OVER w,
+ lead(orbit, 1) IGNORE NULLS OVER w AS lead_ignore,
+ lag(orbit, 1) IGNORE NULLS OVER w AS lag_ignore
+FROM planets
+WINDOW w AS (ORDER BY name ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING)
+;
+ name | orbit | first_value | last_value | nth_value | lead_ignore | lag_ignore
+---------+-------+-------------+------------+-----------+-------------+------------
+ earth | | | | | 88 |
+ jupiter | | 88 | 88 | | 88 |
+ mars | | 88 | 60182 | 60182 | 88 |
+ mercury | 88 | 88 | 90560 | 60182 | 60182 |
+ neptune | 60182 | 88 | 24491 | 60182 | 90560 | 88
+ pluto | 90560 | 88 | 24491 | 60182 | 24491 | 60182
+ saturn | 24491 | 60182 | 224 | 90560 | 224 | 90560
+ uranus | | 90560 | 224 | 24491 | 224 | 24491
+ venus | 224 | 24491 | 224 | 224 | | 24491
+ xyzzy | | 224 | 224 | | | 224
+(10 rows)
+
+-- test partitions
+SELECT name,
+ distance,
+ orbit,
+ first_value(orbit) IGNORE NULLS OVER w,
+ last_value(orbit) IGNORE NULLS OVER w,
+ nth_value(orbit, 2) IGNORE NULLS OVER w,
+ lead(orbit, 1) IGNORE NULLS OVER w AS lead_ignore,
+ lag(orbit, 1) IGNORE NULLS OVER w AS lag_ignore
+FROM planets
+WINDOW w AS (PARTITION BY distance ORDER BY name ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING)
+;
+ name | distance | orbit | first_value | last_value | nth_value | lead_ignore | lag_ignore
+---------+----------+-------+-------------+------------+-----------+-------------+------------
+ earth | close | | | | | 88 |
+ jupiter | close | | 88 | 88 | | 88 |
+ mars | close | | 88 | 224 | 224 | 88 |
+ mercury | close | 88 | 88 | 224 | 224 | 224 |
+ venus | close | 224 | 88 | 224 | 224 | | 88
+ neptune | far | 60182 | 60182 | 24491 | 90560 | 90560 |
+ pluto | far | 90560 | 60182 | 24491 | 90560 | 24491 | 60182
+ saturn | far | 24491 | 60182 | 24491 | 90560 | | 90560
+ uranus | far | | 90560 | 24491 | 24491 | | 24491
+ xyzzy | far | | 24491 | 24491 | | | 24491
+(10 rows)
+
+-- nth_value without nulls
+SELECT x,
+ nth_value(x,2) IGNORE NULLS OVER w
+FROM generate_series(1,5) g(x)
+WINDOW w AS (ORDER BY x ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING EXCLUDE CURRENT ROW);
+ x | nth_value
+---+-----------
+ 1 | 3
+ 2 | 3
+ 3 | 2
+ 4 | 3
+ 5 | 4
+(5 rows)
+
+SELECT x,
+ nth_value(x,2) IGNORE NULLS OVER w
+FROM generate_series(1,5) g(x)
+WINDOW w AS (ORDER BY x ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING);
+ x | nth_value
+---+-----------
+ 1 | 2
+ 2 | 2
+ 3 | 2
+ 4 | 3
+ 5 | 4
+(5 rows)
+
+--cleanup
+DROP TABLE planets CASCADE;
+NOTICE: drop cascades to view planets_view
diff --git a/src/test/regress/sql/window.sql b/src/test/regress/sql/window.sql
index 02f105f070e..85fc621c8db 100644
--- a/src/test/regress/sql/window.sql
+++ b/src/test/regress/sql/window.sql
@@ -1958,3 +1958,165 @@ $$ LANGUAGE SQL STABLE;
EXPLAIN (costs off) SELECT * FROM pg_temp.f(2);
SELECT * FROM pg_temp.f(2);
+
+-- IGNORE NULLS tests
+
+CREATE TEMPORARY TABLE planets (
+ name text,
+ distance text,
+ orbit integer
+);
+
+INSERT INTO planets VALUES
+ ('mercury', 'close', 88),
+ ('venus', 'close', 224),
+ ('earth', 'close', NULL),
+ ('mars', 'close', NULL),
+ ('jupiter', 'close', 4332),
+ ('saturn', 'far', 24491),
+ ('uranus', 'far', NULL),
+ ('neptune', 'far', 60182),
+ ('pluto', 'far', 90560),
+ ('xyzzy', 'far', NULL);
+
+-- test ruleutils
+CREATE VIEW planets_view AS
+SELECT name,
+ orbit,
+ lag(orbit) OVER w AS lag,
+ lag(orbit) RESPECT NULLS OVER w AS lag_respect,
+ lag(orbit) IGNORE NULLS OVER w AS lag_ignore
+FROM planets
+WINDOW w AS (ORDER BY name)
+;
+SELECT pg_get_viewdef('planets_view');
+
+-- lag
+SELECT name,
+ orbit,
+ lag(orbit) OVER w AS lag,
+ lag(orbit) RESPECT NULLS OVER w AS lag_respect,
+ lag(orbit) IGNORE NULLS OVER w AS lag_ignore
+FROM planets
+WINDOW w AS (ORDER BY name)
+;
+
+-- lead
+SELECT name,
+ orbit,
+ lead(orbit) OVER w AS lead,
+ lead(orbit) RESPECT NULLS OVER w AS lead_respect,
+ lead(orbit) IGNORE NULLS OVER w AS lead_ignore
+FROM planets
+WINDOW w AS (ORDER BY name)
+;
+
+-- first_value
+SELECT name,
+ orbit,
+ first_value(orbit) RESPECT NULLS OVER w1,
+ first_value(orbit) IGNORE NULLS OVER w1,
+ first_value(orbit) RESPECT NULLS OVER w2,
+ first_value(orbit) IGNORE NULLS OVER w2
+FROM planets
+WINDOW w1 AS (ORDER BY name ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING),
+ w2 AS (ORDER BY name ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING)
+;
+
+-- nth_value
+SELECT name,
+ orbit,
+ nth_value(orbit, 2) RESPECT NULLS OVER w1,
+ nth_value(orbit, 2) IGNORE NULLS OVER w1,
+ nth_value(orbit, 2) RESPECT NULLS OVER w2,
+ nth_value(orbit, 2) IGNORE NULLS OVER w2
+FROM planets
+WINDOW w1 AS (ORDER BY name ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING),
+ w2 AS (ORDER BY name ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING)
+;
+
+-- last_value
+SELECT name,
+ orbit,
+ last_value(orbit) RESPECT NULLS OVER w1,
+ last_value(orbit) IGNORE NULLS OVER w1,
+ last_value(orbit) RESPECT NULLS OVER w2,
+ last_value(orbit) IGNORE NULLS OVER w2
+FROM planets
+WINDOW w1 AS (ORDER BY name ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING),
+ w2 AS (ORDER BY name ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING)
+;
+
+-- exclude current row
+SELECT name,
+ orbit,
+ first_value(orbit) IGNORE NULLS OVER w,
+ last_value(orbit) IGNORE NULLS OVER w,
+ nth_value(orbit, 2) IGNORE NULLS OVER w,
+ lead(orbit, 1) IGNORE NULLS OVER w AS lead_ignore,
+ lag(orbit, 1) IGNORE NULLS OVER w AS lag_ignore
+FROM planets
+WINDOW w AS (ORDER BY name ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING EXCLUDE CURRENT ROW)
+;
+
+-- valid and invalid functions
+SELECT sum(orbit) OVER () FROM planets; -- succeeds
+SELECT sum(orbit) RESPECT NULLS OVER () FROM planets; -- fails
+SELECT sum(orbit) IGNORE NULLS OVER () FROM planets; -- fails
+SELECT row_number() OVER () FROM planets; -- succeeds
+SELECT row_number() RESPECT NULLS OVER () FROM planets; -- fails
+SELECT row_number() IGNORE NULLS OVER () FROM planets; -- fails
+SELECT rank() OVER () FROM planets; -- succeeds
+SELECT rank() RESPECT NULLS OVER () FROM planets; -- fails
+SELECT rank() IGNORE NULLS OVER () FROM planets; -- fails
+SELECT dense_rank() OVER () FROM planets; -- succeeds
+SELECT dense_rank() RESPECT NULLS OVER () FROM planets; -- fails
+SELECT dense_rank() IGNORE NULLS OVER () FROM planets; -- fails
+SELECT percent_rank() OVER () FROM planets; -- succeeds
+SELECT percent_rank() RESPECT NULLS OVER () FROM planets; -- fails
+SELECT percent_rank() IGNORE NULLS OVER () FROM planets; -- fails
+SELECT cume_dist() OVER () FROM planets; -- succeeds
+SELECT cume_dist() RESPECT NULLS OVER () FROM planets; -- fails
+SELECT cume_dist() IGNORE NULLS OVER () FROM planets; -- fails
+SELECT ntile(1) OVER () FROM planets; -- succeeds
+SELECT ntile(1) RESPECT NULLS OVER () FROM planets; -- fails
+SELECT ntile(1) IGNORE NULLS OVER () FROM planets; -- fails
+
+-- test two consecutive nulls
+update planets set orbit=null where name='jupiter';
+SELECT name,
+ orbit,
+ first_value(orbit) IGNORE NULLS OVER w,
+ last_value(orbit) IGNORE NULLS OVER w,
+ nth_value(orbit, 2) IGNORE NULLS OVER w,
+ lead(orbit, 1) IGNORE NULLS OVER w AS lead_ignore,
+ lag(orbit, 1) IGNORE NULLS OVER w AS lag_ignore
+FROM planets
+WINDOW w AS (ORDER BY name ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING)
+;
+
+-- test partitions
+SELECT name,
+ distance,
+ orbit,
+ first_value(orbit) IGNORE NULLS OVER w,
+ last_value(orbit) IGNORE NULLS OVER w,
+ nth_value(orbit, 2) IGNORE NULLS OVER w,
+ lead(orbit, 1) IGNORE NULLS OVER w AS lead_ignore,
+ lag(orbit, 1) IGNORE NULLS OVER w AS lag_ignore
+FROM planets
+WINDOW w AS (PARTITION BY distance ORDER BY name ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING)
+;
+
+-- nth_value without nulls
+SELECT x,
+ nth_value(x,2) IGNORE NULLS OVER w
+FROM generate_series(1,5) g(x)
+WINDOW w AS (ORDER BY x ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING EXCLUDE CURRENT ROW);
+SELECT x,
+ nth_value(x,2) IGNORE NULLS OVER w
+FROM generate_series(1,5) g(x)
+WINDOW w AS (ORDER BY x ROWS BETWEEN 2 PRECEDING AND 2 FOLLOWING);
+
+--cleanup
+DROP TABLE planets CASCADE;
--
2.43.0
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Subject: Re: Add RESPECT/IGNORE NULLS and FROM FIRST/LAST options
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