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[PATCH v18 6/8] Row pattern recognition patch (docs). 254+ messages / 4 participants [nested] [flat]
* [PATCH v18 6/8] Row pattern recognition patch (docs). @ 2024-05-11 07:11 Tatsuo Ishii <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Tatsuo Ishii @ 2024-05-11 07:11 UTC (permalink / raw) --- doc/src/sgml/advanced.sgml | 82 ++++++++++++++++++++++++++++++++++++ doc/src/sgml/func.sgml | 54 ++++++++++++++++++++++++ doc/src/sgml/ref/select.sgml | 38 ++++++++++++++++- 3 files changed, 172 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml index 755c9f1485..b0b1d1c51e 100644 --- a/doc/src/sgml/advanced.sgml +++ b/doc/src/sgml/advanced.sgml @@ -537,6 +537,88 @@ WHERE pos < 3; <literal>rank</literal> less than 3. </para> + <para> + Row pattern common syntax can be used to perform row pattern recognition + in a query. The row pattern common syntax includes two sub + clauses: <literal>DEFINE</literal> + and <literal>PATTERN</literal>. <literal>DEFINE</literal> defines + definition variables along with an expression. The expression must be a + logical expression, which means it must + return <literal>TRUE</literal>, <literal>FALSE</literal> + or <literal>NULL</literal>. The expression may comprise column references + and functions. Window functions, aggregate functions and subqueries are + not allowed. An example of <literal>DEFINE</literal> is as follows. + +<programlisting> +DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +</programlisting> + + Note that <function>PREV</function> returns the price column in the + previous row if it's called in a context of row pattern recognition. Thus in + the second line the definition variable "UP" is <literal>TRUE</literal> + when the price column in the current row is greater than the price column + in the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when + the price column in the current row is lower than the price column in the + previous row. + </para> + <para> + Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be + used. <literal>PATTERN</literal> defines a sequence of rows that satisfies + certain conditions. For example following <literal>PATTERN</literal> + defines that a row starts with the condition "LOWPRICE", then one or more + rows satisfy "UP" and finally one or more rows satisfy "DOWN". Note that + "+" means one or more matches. Also you can use "*", which means zero or + more matches. If a sequence of rows which satisfies the PATTERN is found, + in the starting row of the sequence of rows all window functions and + aggregates are shown in the target list. Note that aggregations only look + into the matched rows, rather than whole frame. On the second or + subsequent rows all window functions are NULL. Aggregates are NULL or 0 + (count case) depending on its aggregation definition. For rows that do not + match on the PATTERN, all window functions and aggregates are shown AS + NULL too, except count showing 0. This is because the rows do not match, + thus they are in an empty frame. Example of a <literal>SELECT</literal> + using the <literal>DEFINE</literal> and <literal>PATTERN</literal> clause + is as follows. + +<programlisting> +SELECT company, tdate, price, + first_value(price) OVER w, + max(price) OVER w, + count(price) OVER w +FROM stock + WINDOW w AS ( + PARTITION BY company + ORDER BY tdate + ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING + AFTER MATCH SKIP PAST LAST ROW + INITIAL + PATTERN (LOWPRICE UP+ DOWN+) + DEFINE + LOWPRICE AS price <= 100, + UP AS price > PREV(price), + DOWN AS price < PREV(price) +); +</programlisting> +<screen> + company | tdate | price | first_value | max | count +----------+------------+-------+-------------+-----+------- + company1 | 2023-07-01 | 100 | 100 | 200 | 4 + company1 | 2023-07-02 | 200 | | | 0 + company1 | 2023-07-03 | 150 | | | 0 + company1 | 2023-07-04 | 140 | | | 0 + company1 | 2023-07-05 | 150 | | | 0 + company1 | 2023-07-06 | 90 | 90 | 130 | 4 + company1 | 2023-07-07 | 110 | | | 0 + company1 | 2023-07-08 | 130 | | | 0 + company1 | 2023-07-09 | 120 | | | 0 + company1 | 2023-07-10 | 130 | | | 0 +(10 rows) +</screen> + </para> + <para> When a query involves multiple window functions, it is possible to write out each one with a separate <literal>OVER</literal> clause, but this is diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 17c44bc338..8dbab31300 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -23124,6 +23124,7 @@ SELECT count(*) FROM sometable; returns <literal>NULL</literal> if there is no such row. </para></entry> </row> + </tbody> </tgroup> </table> @@ -23163,6 +23164,59 @@ SELECT count(*) FROM sometable; Other frame specifications can be used to obtain other effects. </para> + <para> + Row pattern recognition navigation functions are listed in + <xref linkend="functions-rpr-navigation-table"/>. These functions + can be used to describe DEFINE clause of Row pattern recognition. + </para> + + <table id="functions-rpr-navigation-table"> + <title>Row Pattern Navigation Functions</title> + <tgroup cols="1"> + <thead> + <row> + <entry role="func_table_entry"><para role="func_signature"> + Function + </para> + <para> + Description + </para></entry> + </row> + </thead> + + <tbody> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>prev</primary> + </indexterm> + <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the previous row; + returns NULL if there is no previous row in the window frame. + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>next</primary> + </indexterm> + <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> ) + <returnvalue>anyelement</returnvalue> + </para> + <para> + Returns the column value at the next row; + returns NULL if there is no next row in the window frame. + </para></entry> + </row> + + </tbody> + </tgroup> + </table> + <note> <para> The SQL standard defines a <literal>RESPECT NULLS</literal> or diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 066aed44e6..8f18718d58 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -969,8 +969,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl The <replaceable class="parameter">frame_clause</replaceable> can be one of <synopsis> -{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] -{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] +{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] +{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax] </synopsis> where <replaceable>frame_start</replaceable> @@ -1077,6 +1077,40 @@ EXCLUDE NO OTHERS a given peer group will be in the frame or excluded from it. </para> + <para> + The + optional <replaceable class="parameter">row_pattern_common_syntax</replaceable> + defines the <firstterm>row pattern recognition condition</firstterm> for + this + window. <replaceable class="parameter">row_pattern_common_syntax</replaceable> + includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST + ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls + how to proceed to next row position after a match + found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the + default) next row position is next to the last row of previous match. On + the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next + row position is always next to the last row of previous + match. <literal>DEFINE</literal> defines definition variables along with a + boolean expression. <literal>PATTERN</literal> defines a sequence of rows + that satisfies certain conditions using variables defined + in <literal>DEFINE</literal> clause. If the variable is not defined in + the <literal>DEFINE</literal> clause, it is implicitly assumed + following is defined in the <literal>DEFINE</literal> clause. + +<synopsis> +<literal>variable_name</literal> AS TRUE +</synopsis> + + Note that the maximu number of variables defined + in <literal>DEFINE</literal> clause is 26. + +<synopsis> +[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ] +PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...] +DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...] +</synopsis> + </para> + <para> The purpose of a <literal>WINDOW</literal> clause is to specify the behavior of <firstterm>window functions</firstterm> appearing in the query's -- 2.25.1 ----Next_Part(Sat_May_11_16_23_07_2024_789)-- Content-Type: Text/X-Patch; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="v18-0007-Row-pattern-recognition-patch-tests.patch" ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-05-29 12:35 Samba Siva <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva @ 2026-05-29 12:35 UTC (permalink / raw) - Introduced AcquireSampleRowsFunc_hook for extensions to override row sampling. - Updated analyze.c to utilize the hook if registered. - Added tests to ensure ANALYZE completes without errors with the new hook. --- doc/src/sgml/xfunc.sgml | 10 ++++++++++ src/backend/commands/analyze.c | 24 ++++++++++++++++++++---- src/include/commands/vacuum.h | 11 +++++++++++ src/test/regress/expected/analyze.out | 20 ++++++++++++++++++++ src/test/regress/parallel_schedule | 1 + src/test/regress/sql/analyze.sql | 24 ++++++++++++++++++++++++ 6 files changed, 86 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/analyze.out create mode 100644 src/test/regress/sql/analyze.sql diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml index 1eb5abffd8..f1ef025ae2 100644 --- a/doc/src/sgml/xfunc.sgml +++ b/doc/src/sgml/xfunc.sgml @@ -4203,4 +4203,14 @@ supportfn(internal) returns internal To create such conditions, the support function must implement the <literal>SupportRequestIndexCondition</literal> request type. </para> + + <para> + The hook variable <varname>AcquireSampleRowsFunc_hook</varname> allows extensions + to override the row sampling function during <command>ANALYZE</command> for regular + heap relations. This is useful for extensions/systems which implement distributed + databases and want to sample rows from remote nodes instead of the local heap. + The hook function fills the provided <literal>rows[]</literal> buffer with at most + <literal>targrows</literal> heap tuples and sets <literal>*totalrows</literal> to the + estimated total live row count of the relation. + </para> </sect1> diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c index 4fffb76e55..3560acdff1 100644 --- a/src/backend/commands/analyze.c +++ b/src/backend/commands/analyze.c @@ -74,6 +74,8 @@ int default_statistics_target = 100; static MemoryContext anl_context = NULL; static BufferAccessStrategy vac_strategy; +/* Hook for plugins to acquire sample rows for ANALYZE */ +AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook = NULL; static void do_analyze_rel(Relation onerel, VacuumParams *params, List *va_cols, @@ -188,8 +190,15 @@ analyze_rel(Oid relid, RangeVar *relation, if (onerel->rd_rel->relkind == RELKIND_RELATION || onerel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so we'll use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so we'll use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; /* Also get regular table's size */ relpages = RelationGetNumberOfBlocks(onerel); } @@ -1467,8 +1476,15 @@ acquire_inherited_sample_rows(Relation onerel, int elevel, if (childrel->rd_rel->relkind == RELKIND_RELATION || childrel->rd_rel->relkind == RELKIND_MATVIEW) { - /* Regular table, so use the regular row acquisition function */ - acquirefunc = acquire_sample_rows; + /* + * Regular table, so use the regular row acquisition function. + * If a plugin has registered a hook to acquire sample rows, use it; + * otherwise use the default function. + */ + if (AcquireSampleRowsFunc_hook) + acquirefunc = AcquireSampleRowsFunc_hook; + else + acquirefunc = acquire_sample_rows; relpages = RelationGetNumberOfBlocks(childrel); } else if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h index bc37a80dc7..146f936861 100644 --- a/src/include/commands/vacuum.h +++ b/src/include/commands/vacuum.h @@ -21,6 +21,7 @@ #include "catalog/pg_class.h" #include "catalog/pg_statistic.h" #include "catalog/pg_type.h" +#include "foreign/fdwapi.h" #include "parser/parse_node.h" #include "storage/buf.h" #include "storage/lock.h" @@ -113,6 +114,9 @@ typedef void (*AnalyzeAttrComputeStatsFunc) (VacAttrStatsP stats, int samplerows, double totalrows); +/* Hook type for plugins to acquire sample rows for ANALYZE */ +typedef AcquireSampleRowsFunc AcquireSampleRowsFunc_hook_type; + typedef struct VacAttrStats { /* @@ -334,6 +338,13 @@ extern PGDLLIMPORT int vacuum_cost_limit; extern PGDLLIMPORT int64 parallel_vacuum_worker_delay_ns; +/* + * Hook for plugins to override row sampling during ANALYZE. + * Also applies to child relations of partitioned/inherited tables. + * See acquire_sample_rows() in src/backend/commands/analyze.c. + */ +extern PGDLLIMPORT AcquireSampleRowsFunc_hook_type AcquireSampleRowsFunc_hook; + /* in commands/vacuum.c */ extern void ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel); extern void vacuum(List *relations, VacuumParams *params, diff --git a/src/test/regress/expected/analyze.out b/src/test/regress/expected/analyze.out new file mode 100644 index 0000000000..5bb6bbc45b --- /dev/null +++ b/src/test/regress/expected/analyze.out @@ -0,0 +1,20 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; +-- Should complete without error +ANALYZE employees; +DROP TABLE employees; diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule index e1e0c54019..71978ef858 100644 --- a/src/test/regress/parallel_schedule +++ b/src/test/regress/parallel_schedule @@ -94,6 +94,7 @@ test: vacuum_parallel # Run this alone, because concurrent DROP TABLE would make non-superuser # "ANALYZE;" fail with "relation with OID $n does not exist". test: maintain_every +test: analyze # no relation related tests can be put in this group test: publication subscription diff --git a/src/test/regress/sql/analyze.sql b/src/test/regress/sql/analyze.sql new file mode 100644 index 0000000000..e0bc84e9f9 --- /dev/null +++ b/src/test/regress/sql/analyze.sql @@ -0,0 +1,24 @@ +-- Test AcquireSampleRowsFunc_hook +-- Usually this would be tested via a C extension. +-- Here we just confirm this does not break the existing ANALYZE code +-- by verifying that ANALYZE completes without error. + +CREATE TABLE employees ( + id SERIAL PRIMARY KEY, + name TEXT, + department TEXT, + salary NUMERIC +); + +INSERT INTO employees + SELECT + i, + 'Employee ' || i, + 'Department ' || (i % 5), + (i % 100) * 1000 + 50000 + FROM generate_series(1, 1000) i; + +-- Should complete without error +ANALYZE employees; + +DROP TABLE employees; -- 2.50.1 (Apple Git-155) ------=_Part_741589_445982825.1782438414800-- ^ permalink raw reply [nested|flat] 254+ messages in thread
* [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-06-26 01:46 Samba Siva Reddy Chinta <[email protected]> 0 siblings, 1 reply; 254+ messages in thread From: Samba Siva Reddy Chinta @ 2026-06-26 01:46 UTC (permalink / raw) To: pgsql-hackers <[email protected]> Hi all, Attached is a patch that adds a hook, AcquireSampleRowsFunc_hook, allowing extensions to override the row sampling function used during ANALYZE for regular heap relations. Motivation Extensions that implement horizontal scaling of tables currently have no clean way to participate in ANALYZE's row sampling. The default acquire_sample_rows() only knows how to sample the local heap, so a distributed-table extension wanting accurate statistics has to either: maintain its own separate stats-collection machinery outside of ANALYZE entirely, or duplicate/reimplement parts of analyze.c's sampling logic to pull rows from remote nodes. This hook lets such an extension plug into the existing ANALYZE code path and supply its own row acquisition function, without having to reinvent stats collection or duplicate logic that already exists in core. What the patch does Adds AcquireSampleRowsFunc_hook (typed identically to AcquireSampleRowsFunc) in vacuum.h. In analyze.c, both analyze_rel() and acquire_inherited_sample_rows() check the hook and use it in place of acquire_sample_rows() when set. Adds doc text in xfunc.sgml describing the hook's contract (fill rows[] up to targrows, set *totalrows). Adds a regression test confirming ANALYZE still completes normally with the hook unset (the hook itself needs a C extension to exercise meaningfully, so this just guards against regressions in the unset case). ​Regards, Samba Siva Reddy http://sambasivareddy.in ^ permalink raw reply [nested|flat] 254+ messages in thread
* Re: [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-06-26 12:41 Ashutosh Bapat <[email protected]> parent: Samba Siva Reddy Chinta <[email protected]> 0 siblings, 1 reply; 254+ messages in thread From: Ashutosh Bapat @ 2026-06-26 12:41 UTC (permalink / raw) To: Samba Siva Reddy Chinta <[email protected]>; +Cc: pgsql-hackers <[email protected]> Hi Samba Siva, On Fri, Jun 26, 2026 at 7:17 AM Samba Siva Reddy Chinta <[email protected]> wrote: > > Hi all, > > Attached is a patch that adds a hook, AcquireSampleRowsFunc_hook, allowing extensions to override the row sampling function used during ANALYZE for regular heap relations. > > Motivation > > Extensions that implement horizontal scaling of tables currently have no clean way to participate in ANALYZE's row sampling. The default acquire_sample_rows() only knows how to sample the local heap, so a distributed-table extension wanting accurate statistics has to either: > > maintain its own separate stats-collection machinery outside of ANALYZE entirely, or > duplicate/reimplement parts of analyze.c's sampling logic to pull rows from remote nodes. > > This hook lets such an extension plug into the existing ANALYZE code path and supply its own row acquisition function, without having to reinvent stats collection or duplicate logic that already exists in core. > > What the patch does > > Adds AcquireSampleRowsFunc_hook (typed identically to AcquireSampleRowsFunc) in vacuum.h. > In analyze.c, both analyze_rel() and acquire_inherited_sample_rows() check the hook and use it in place of acquire_sample_rows() when set. > Adds doc text in xfunc.sgml describing the hook's contract (fill rows[] up to targrows, set *totalrows). > Adds a regression test confirming ANALYZE still completes normally with the hook unset (the hook itself needs a C extension to exercise meaningfully, so this just guards against regressions in the unset case). > If you have implemented sharding using inheritance or partitioning and FDW, the facility to fetch statistics of foreign tables from foreign server can be useful here. IIUC, there is a limitation on using it for inherited foreign tables, but it's worth exploring and improving for your usecase. -- Best Wishes, Ashutosh Bapat ^ permalink raw reply [nested|flat] 254+ messages in thread
* Re: [PATCH] Add hook for plugins to acquire sample rows during ANALYZE @ 2026-07-05 02:22 Samba Siva Reddy Chinta <[email protected]> parent: Ashutosh Bapat <[email protected]> 0 siblings, 0 replies; 254+ messages in thread From: Samba Siva Reddy Chinta @ 2026-07-05 02:22 UTC (permalink / raw) To: Ashutosh Bapat <[email protected]>; +Cc: pgsql-hackers <[email protected]> Hi Ashutosh, If you have implemented sharding using inheritance or partitioning and FDW, the facility to fetch statistics of foreign tables from foreign server can be useful here. IIUC, there is a limitation on using it for inherited foreign tables, but it's worth exploring and improving for your usecase. Thanks for the suggestion. To clarify, this is not FDW-based sharding. The shards here are plain PostgreSQL tables distributed across the nodes like Citus, when a table is distributed, the base table remains on the coordinator and its shards spread across the workers as regular PostgreSQL heap tables. Since there are no foreign tables involved, the FDW stats-fetching mechanism does not apply here. The base table holds no actual row data, but the shards as the real data - which is precisely the gap AcquireSampleRowsFunc_hook is meant to address. Happy to clarify further if needed. Thanks, Samba Siva Reddy From: Ashutosh Bapat <[email protected]> To: "Samba Siva Reddy Chinta"<[email protected]> Cc: "pgsql-hackers"<[email protected]> Date: Fri, 26 Jun 2026 18:11:50 +0530 Subject: Re: [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Hi Samba Siva, On Fri, Jun 26, 2026 at 7:17 AM Samba Siva Reddy Chinta < mailto:[email protected] > wrote: > > Hi all, > > Attached is a patch that adds a hook, AcquireSampleRowsFunc_hook, allowing extensions to override the row sampling function used during ANALYZE for regular heap relations. > > Motivation > > Extensions that implement horizontal scaling of tables currently have no clean way to participate in ANALYZE's row sampling. The default acquire_sample_rows() only knows how to sample the local heap, so a distributed-table extension wanting accurate statistics has to either: > > maintain its own separate stats-collection machinery outside of ANALYZE entirely, or > duplicate/reimplement parts of analyze.c's sampling logic to pull rows from remote nodes. > > This hook lets such an extension plug into the existing ANALYZE code path and supply its own row acquisition function, without having to reinvent stats collection or duplicate logic that already exists in core. > > What the patch does > > Adds AcquireSampleRowsFunc_hook (typed identically to AcquireSampleRowsFunc) in vacuum.h. > In analyze.c, both analyze_rel() and acquire_inherited_sample_rows() check the hook and use it in place of acquire_sample_rows() when set. > Adds doc text in xfunc.sgml describing the hook's contract (fill rows[] up to targrows, set *totalrows). > Adds a regression test confirming ANALYZE still completes normally with the hook unset (the hook itself needs a C extension to exercise meaningfully, so this just guards against regressions in the unset case). > If you have implemented sharding using inheritance or partitioning and FDW, the facility to fetch statistics of foreign tables from foreign server can be useful here. IIUC, there is a limitation on using it for inherited foreign tables, but it's worth exploring and improving for your usecase. -- Best Wishes, Ashutosh Bapat Regards, Samba Siva Reddy http://sambasivareddy.in ^ permalink raw reply [nested|flat] 254+ messages in thread
end of thread, other threads:[~2026-07-05 02:22 UTC | newest] Thread overview: 254+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2024-05-11 07:11 [PATCH v18 6/8] Row pattern recognition patch (docs). Tatsuo Ishii <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-05-29 12:35 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva <[email protected]> 2026-06-26 01:46 [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva Reddy Chinta <[email protected]> 2026-06-26 12:41 ` Re: [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Ashutosh Bapat <[email protected]> 2026-07-05 02:22 ` Re: [PATCH] Add hook for plugins to acquire sample rows during ANALYZE Samba Siva Reddy Chinta <[email protected]>
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