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[PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
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* [PATCH] Test to demonstrate bug in commit 0d3dba38c7 and to verify a fix.
@ 2026-05-12 10:27 Antonin Houska <[email protected]>
  0 siblings, 0 replies; 213+ messages in thread

From: Antonin Houska @ 2026-05-12 10:27 UTC (permalink / raw)

The fix: https://www.postgresql.org/message-id/77611.1778055944%40localhost
---
 src/backend/access/transam/xact.c             |   2 +
 src/backend/commands/repack_worker.c          |   2 +
 src/test/isolation/isolationtester.c          |   9 +-
 .../expected/repack_running_xacts.out         |  81 ++++++++++++
 .../specs/repack_running_xacts.spec           | 119 ++++++++++++++++++
 5 files changed, 212 insertions(+), 1 deletion(-)
 create mode 100644 src/test/modules/injection_points/expected/repack_running_xacts.out
 create mode 100644 src/test/modules/injection_points/specs/repack_running_xacts.spec

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 5586fbe5b07..b63ee166028 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -65,6 +65,7 @@
 #include "utils/builtins.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
+#include "utils/injection_point.h"
 #include "utils/inval.h"
 #include "utils/memutils.h"
 #include "utils/relmapper.h"
@@ -2428,6 +2429,7 @@ CommitTransaction(void)
 	 * must be done _before_ releasing locks we hold and _after_
 	 * RecordTransactionCommit.
 	 */
+	INJECTION_POINT("before-end-transaction", NULL);
 	ProcArrayEndTransaction(MyProc, latestXid);
 
 	/*
diff --git a/src/backend/commands/repack_worker.c b/src/backend/commands/repack_worker.c
index c40f8c98e06..6835626d677 100644
--- a/src/backend/commands/repack_worker.c
+++ b/src/backend/commands/repack_worker.c
@@ -26,6 +26,7 @@
 #include "storage/ipc.h"
 #include "storage/proc.h"
 #include "tcop/tcopprot.h"
+#include "utils/injection_point.h"
 #include "utils/memutils.h"
 
 #define REPL_PLUGIN_NAME   "pgrepack"
@@ -233,6 +234,7 @@ repack_setup_logical_decoding(Oid relid)
 	 * Neither prepare_write nor do_write callback nor update_progress is
 	 * useful for us.
 	 */
+	INJECTION_POINT("before-create-decoding-context", NULL);
 	ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
 									NIL,
 									true,
diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index 440c875b8ac..8f17ee412c9 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -216,15 +216,22 @@ main(int argc, char **argv)
 	 * exactly expect concurrent use of test tables.  However, autovacuum will
 	 * occasionally take AccessExclusiveLock to truncate a table, and we must
 	 * ignore that transient wait.
+	 *
+	 * If the session's backend is blocked, and if its background worker is
+	 * waiting on an injection point, we assume that the injection point is
+	 * the reason for the backend to be blocked. That's what we check in the
+	 * second query of the UNION. XXX Should we use a separate query for that?
 	 */
 	initPQExpBuffer(&wait_query);
 	appendPQExpBufferStr(&wait_query,
+						 "WITH blocking(res) AS ("
 						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked($1, '{");
 	/* The spec syntax requires at least one session; assume that here. */
 	appendPQExpBufferStr(&wait_query, conns[1].backend_pid_str);
 	for (i = 2; i < nconns; i++)
 		appendPQExpBuffer(&wait_query, ",%s", conns[i].backend_pid_str);
-	appendPQExpBufferStr(&wait_query, "}')");
+	appendPQExpBufferStr(&wait_query, "}') UNION "
+						 "SELECT pg_catalog.pg_isolation_test_session_is_blocked(pid, '{}') FROM pg_stat_activity WHERE leader_pid=$1) SELECT bool_or(res) FROM blocking");
 
 	res = PQprepare(conns[0].conn, PREP_WAITING, wait_query.data, 0, NULL);
 	if (PQresultStatus(res) != PGRES_COMMAND_OK)
diff --git a/src/test/modules/injection_points/expected/repack_running_xacts.out b/src/test/modules/injection_points/expected/repack_running_xacts.out
new file mode 100644
index 00000000000..271fe2b97cb
--- /dev/null
+++ b/src/test/modules/injection_points/expected/repack_running_xacts.out
@@ -0,0 +1,81 @@
+Parsed test spec with 5 sessions
+
+starting permutation: repack s3_assign_xid wakeup_bcdc s4_changes s4_attach s4_commit s3_commit s5_assign_xid wakeup_bet s5_commit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step repack: 
+	REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step s3_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+
+step wakeup_bcdc: 
+	SELECT injection_points_wakeup('before-create-decoding-context');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step s4_changes: 
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+
+step s4_attach: 
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+
+injection_points_set_local
+--------------------------
+                          
+(1 row)
+
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step s4_commit: 
+	COMMIT;
+ <waiting ...>
+step s3_commit: 
+	COMMIT;
+
+step s5_assign_xid: 
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+
+step wakeup_bet: 
+	SELECT injection_points_wakeup('before-end-transaction');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+step repack: <... completed>
+step s4_commit: <... completed>
+step s5_commit: 
+	COMMIT;
+
+step check: 
+	TABLE repack_test;
+
+i|j
+-+-
+(0 rows)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
diff --git a/src/test/modules/injection_points/specs/repack_running_xacts.spec b/src/test/modules/injection_points/specs/repack_running_xacts.spec
new file mode 100644
index 00000000000..1f878514046
--- /dev/null
+++ b/src/test/modules/injection_points/specs/repack_running_xacts.spec
@@ -0,0 +1,119 @@
+setup
+{
+	CREATE EXTENSION injection_points;
+	CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+	CREATE TABLE aux(i int);
+}
+
+teardown
+{
+	DROP TABLE repack_test;
+	DROP TABLE aux;
+	DROP EXTENSION injection_points;
+}
+
+session s1
+setup
+{
+	SELECT injection_points_attach('before-create-decoding-context', 'wait');
+}
+step repack
+{
+	REPACK (CONCURRENTLY) repack_test;
+}
+step check
+{
+	TABLE repack_test;
+}
+teardown
+{
+	SELECT injection_points_detach('before-create-decoding-context');
+}
+
+session s2
+step wakeup_bcdc
+{
+	SELECT injection_points_wakeup('before-create-decoding-context');
+}
+step wakeup_bet
+{
+	SELECT injection_points_wakeup('before-end-transaction');
+}
+
+session s3
+step s3_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (1);
+}
+step s3_commit
+{
+	COMMIT;
+}
+
+session s4
+step s4_changes
+{
+	BEGIN;
+	INSERT INTO repack_test(i, j) VALUES (1, 1);
+}
+# Do not attach in the setup section, that would be too soon.
+step s4_attach
+{
+	SELECT injection_points_set_local();
+	SELECT injection_points_attach('before-end-transaction', 'wait');
+}
+step s4_commit
+{
+	COMMIT;
+}
+teardown
+{
+	SELECT injection_points_detach('before-end-transaction');
+}
+
+session s5
+step s5_assign_xid
+{
+	BEGIN;
+	INSERT INTO aux VALUES (2);
+}
+step s5_commit
+{
+	COMMIT;
+}
+
+permutation
+repack
+# Assign XID so that a running transaction prevents the snapshot builder from
+# reaching CONSISTENT state immediately. It will wait for this to complete
+# after having reached BUILDING_SNAPSHOT.
+s3_assign_xid
+# Let the decoding setup start.
+wakeup_bcdc
+# Likewise, the snapshot builder will wait for the s4's xact to complete after
+# having reached FULL_SNAPSHOT. This is the problematic transaction, so let it
+# do some changes.
+s4_changes
+# Attach to the 'before-end-transaction' injection point that s4 will need
+# during commit.
+s4_attach
+# Only write commit record for s4, but do not remove the xact from procarray
+# yet. Thus the snapshot builder still needs to wait.
+s4_commit
+# Let the snapshot builder proceed to FULL_SNAPSHOT.
+s3_commit
+# Start another transaction so that CONSISTENT is not reached "directly",
+# i.e. due to no running transaction. It's important here that builder->xmin
+# does not advance.
+s5_assign_xid
+# Remove s4 xact from procarray, and thus reach the CONSISTENT state. Since
+# the COMMIT appeared in WAL too early (i.e. when the snapshot builder state
+# did not allow decoding of COMMIT records yet), the snapshot builder will
+# consider s4 running. This is also due to returning from
+# SnapBuildProcessRunningXacts() too early, w/o advancing builder->xmin.
+wakeup_bet
+# s5 is not needed anymore
+s5_commit
+# Show that the data changes performed by s4 are lost.
+check
-- 
2.47.3


--=-=-=--





^ permalink  raw  reply  [nested|flat] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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] 213+ 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; 213+ 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--






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