agora inbox for [email protected]  

help / color / mirror / Atom feed

[PATCH 2/9] rename setup_logical_decoding to repack_setup_logical_decoding
109+ messages / 2 participants
[nested] [flat]

* [PATCH 2/9] rename setup_logical_decoding to repack_setup_logical_decoding
@ 2026-03-12 15:05  Álvaro Herrera <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Álvaro Herrera @ 2026-03-12 15:05 UTC (permalink / raw)

---
 src/backend/commands/cluster.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index da4919e497a..db3980b84f5 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -274,7 +274,7 @@ static List *get_tables_to_repack_partitioned(RepackCommand cmd,
 static bool repack_is_permitted_for_relation(RepackCommand cmd,
 											 Oid relid, Oid userid);
 
-static LogicalDecodingContext *setup_logical_decoding(Oid relid);
+static LogicalDecodingContext *repack_setup_logical_decoding(Oid relid);
 static bool decode_concurrent_changes(LogicalDecodingContext *ctx,
 									  DecodingWorkerShared *shared);
 static void apply_concurrent_changes(BufFile *file, ChangeDest *dest);
@@ -612,7 +612,7 @@ cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
 	{
 		/*
 		 * Make sure we have no XID assigned, otherwise call of
-		 * setup_logical_decoding() can cause a deadlock.
+		 * repack_setup_logical_decoding() can cause a deadlock.
 		 *
 		 * The existence of transaction block actually does not imply that XID
 		 * was already assigned, but it very likely is. We might want to check
@@ -2620,7 +2620,7 @@ change_useless_for_repack(XLogRecordBuffer *buf)
  * crash by restarting all the work from scratch).
  */
 static LogicalDecodingContext *
-setup_logical_decoding(Oid relid)
+repack_setup_logical_decoding(Oid relid)
 {
 	Relation	rel;
 	Oid			toastrelid;
@@ -4044,7 +4044,7 @@ repack_worker_internal(dsm_segment *seg)
 	/*
 	 * Prepare to capture the concurrent data changes ourselves.
 	 */
-	decoding_ctx = setup_logical_decoding(shared->relid);
+	decoding_ctx = repack_setup_logical_decoding(shared->relid);
 
 	/* Announce that we're ready. */
 	SpinLockAcquire(&shared->mutex);
-- 
2.47.3


--pnppmxqkefjd4hu2
Content-Type: text/plain; charset=utf-8
Content-Disposition: attachment;
	filename="0003-remove-excess-parens-around-ereport.nocfbot.txt"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 3/4] Add invalidation-based retry loop for Alter/Drop Subscription
@ 2026-07-03 14:03  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:03 UTC (permalink / raw)

Following the approach of RangeVarGetRelidExtended() for relations, add a
retry loop that includes name resolution, ownership check, and lock
acquisition in AlterSubscription() and DropSubscription().

The loop records SharedInvalidMessageCounter, resolves the subscription name
to an OID, checks ownership, then locks the subscription. If the invalidation
counter changed (indicating concurrent DDL), we save the current OID and
retry. On the next iteration, if the name still resolves to the same OID,
we're done (already holding the correct lock). If it resolves to a different
OID, we release the old lock and acquire the new one.

This mirrors RangeVarGetRelidExtended()'s behavior: the lock is kept across
retries to avoid a window where another session could have committed concurrent
DDL modifying the ownership and/or the name resolution.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/subscriptioncmds.c | 167 +++++++++++++++++-------
 1 file changed, 118 insertions(+), 49 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index e23b366a87d..866341c2cfb 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -50,6 +50,7 @@
 #include "replication/walsender.h"
 #include "replication/worker_internal.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/guc.h"
@@ -1592,23 +1593,67 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 
 	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
 
-	/* Fetch the existing tuple. */
-	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, ObjectIdGetDatum(MyDatabaseId),
-							  CStringGetDatum(stmt->subname));
+	/*
+	 * Lock the subscription so nobody else can do anything with it.
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
+	 */
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-	subid = form->oid;
+			tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME,
+									  ObjectIdGetDatum(MyDatabaseId),
+									  CStringGetDatum(stmt->subname));
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer. So we're done. If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			heap_freetuple(tup);
+		}
+	}
 
 	/* parse and check options */
 	switch (stmt->kind)
@@ -1686,25 +1731,6 @@ AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
 			orig_conninfo_needed = false;
 	}
 
-	heap_freetuple(tup);
-
-	/* Lock the subscription so nobody else can do anything with it. */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
-
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * DROP or ALTER may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
-
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
-
-	form = (Form_pg_subscription) GETSTRUCT(tup);
-
 	/*
 	 * Skip ACL checks on the subscription's foreign server, if any. If
 	 * changing the server (or replacing it with a raw connection), then the
@@ -2570,11 +2596,6 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subid = form->oid;
 
-	/* must be owner */
-	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
-					   stmt->subname);
-
 	/* DROP hook for the subscription being removed */
 	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
 
@@ -2583,20 +2604,68 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	/*
 	 * Lock the subscription so nobody else can do anything with it (including
 	 * the replication workers).
+	 *
+	 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+	 * name, check ownership, and lock inside a loop. If invalidation messages
+	 * arrive (indicating concurrent DDL), we retry. We keep the lock held
+	 * across retries and only release it if the name resolves to a different
+	 * OID on the next iteration.
 	 */
-	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+	{
+		Oid			oldSubId = InvalidOid;
+		bool		retry = false;
 
-	/*
-	 * Re-read the subscription tuple after acquiring the lock. A concurrent
-	 * ALTER or DROP may have committed before we acquired the lock.
-	 */
-	tup = SearchSysCache1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+		for (;;)
+		{
+			uint64		inval_count = SharedInvalidMessageCounter;
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("subscription \"%s\" does not exist",
-						stmt->subname)));
+			tup = SearchSysCache2(SUBSCRIPTIONNAME,
+								  ObjectIdGetDatum(MyDatabaseId),
+								  CStringGetDatum(stmt->subname));
+
+			if (!HeapTupleIsValid(tup))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_OBJECT),
+						 errmsg("subscription \"%s\" does not exist",
+								stmt->subname)));
+
+			form = (Form_pg_subscription) GETSTRUCT(tup);
+			subid = form->oid;
+
+			if (!object_ownercheck(SubscriptionRelationId, subid,
+								   GetUserId()))
+			{
+				ReleaseSysCache(tup);
+				aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+							   stmt->subname);
+			}
+
+			/*
+			 * If upon retry we get the same OID, the invalidation messages
+			 * did not change the final answer.  So we're done.  If we got a
+			 * different OID, unlock the old one and lock the new one below.
+			 */
+			if (retry)
+			{
+				if (subid == oldSubId)
+					break;
+				UnlockSharedObject(SubscriptionRelationId, oldSubId, 0,
+								   AccessExclusiveLock);
+			}
+
+			LockSharedObject(SubscriptionRelationId, subid, 0,
+							 AccessExclusiveLock);
+
+			/* If no invalidation messages, we're done. */
+			if (inval_count == SharedInvalidMessageCounter)
+				break;
+
+			/* Something may have changed, retry. */
+			retry = true;
+			oldSubId = subid;
+			ReleaseSysCache(tup);
+		}
+	}
 
 	form = (Form_pg_subscription) GETSTRUCT(tup);
 	subowner = form->subowner;
-- 
2.34.1


--3eAVwo4vDNlHc8RC
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
	filename="v3-0004-Add-invalidation-based-retry-loop-for-AlterPublic.patch"



^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v4 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by: Dilip Kumar <[email protected]>
Reviewed-by: Hayato Kuroda (Fujitsu) <[email protected]>
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--b+bwjVhifbzgesmw--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--3eAVwo4vDNlHc8RC--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v4 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by: Dilip Kumar <[email protected]>
Reviewed-by: Hayato Kuroda (Fujitsu) <[email protected]>
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--b+bwjVhifbzgesmw--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--3eAVwo4vDNlHc8RC--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v4 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by: Dilip Kumar <[email protected]>
Reviewed-by: Hayato Kuroda (Fujitsu) <[email protected]>
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--b+bwjVhifbzgesmw--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--3eAVwo4vDNlHc8RC--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v4 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by: Dilip Kumar <[email protected]>
Reviewed-by: Hayato Kuroda (Fujitsu) <[email protected]>
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--b+bwjVhifbzgesmw--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--3eAVwo4vDNlHc8RC--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v4 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by: Dilip Kumar <[email protected]>
Reviewed-by: Hayato Kuroda (Fujitsu) <[email protected]>
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--b+bwjVhifbzgesmw--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--3eAVwo4vDNlHc8RC--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v4 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by: Dilip Kumar <[email protected]>
Reviewed-by: Hayato Kuroda (Fujitsu) <[email protected]>
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--b+bwjVhifbzgesmw--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--3eAVwo4vDNlHc8RC--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v4 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by: Dilip Kumar <[email protected]>
Reviewed-by: Hayato Kuroda (Fujitsu) <[email protected]>
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--b+bwjVhifbzgesmw--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--3eAVwo4vDNlHc8RC--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v4 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by: Dilip Kumar <[email protected]>
Reviewed-by: Hayato Kuroda (Fujitsu) <[email protected]>
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--b+bwjVhifbzgesmw--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--3eAVwo4vDNlHc8RC--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--3eAVwo4vDNlHc8RC--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v4 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by: Dilip Kumar <[email protected]>
Reviewed-by: Hayato Kuroda (Fujitsu) <[email protected]>
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--b+bwjVhifbzgesmw--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--3eAVwo4vDNlHc8RC--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v4 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by: Dilip Kumar <[email protected]>
Reviewed-by: Hayato Kuroda (Fujitsu) <[email protected]>
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--b+bwjVhifbzgesmw--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread

* [PATCH v3 4/4] Add invalidation-based retry loop for AlterPublication
@ 2026-07-03 14:46  Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 109+ messages in thread

From: Bertrand Drouvot @ 2026-07-03 14:46 UTC (permalink / raw)

Apply the same RangeVarGetRelidExtended() style retry loop to
AlterPublication()'s tables/schemas branch that was added for subscriptions
in commit XXXX.

Previously, this branch resolved the publication name and checked ownership
at the top of AlterPublication(), then locked and re-read by OID. This left a
window where concurrent DDL could have modified the ownership and/or the name
resolution

Now the tables/schemas branch has its own complete retry loop: name
resolution, ownership check, and lock acquisition all inside the loop.

Author: Bertrand Drouvot <[email protected]>
Reviewed-by:
Discussion: https://postgr.es/m/akZUpiDa1UfmzYxL%40bdtpg
---
 src/backend/commands/publicationcmds.c | 105 +++++++++++++++++--------
 1 file changed, 72 insertions(+), 33 deletions(-)
 100.0% src/backend/commands/

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 440adb356ad..dfd707bc7d7 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -39,6 +39,7 @@
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/lmgr.h"
+#include "storage/sinval.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/inval.h"
@@ -1662,54 +1663,92 @@ AlterPublication(ParseState *pstate, AlterPublicationStmt *stmt)
 
 	rel = table_open(PublicationRelationId, RowExclusiveLock);
 
-	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
-							  CStringGetDatum(stmt->pubname));
+	if (stmt->options)
+	{
+		tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+								  CStringGetDatum(stmt->pubname));
 
-	if (!HeapTupleIsValid(tup))
-		ereport(ERROR,
-				(errcode(ERRCODE_UNDEFINED_OBJECT),
-				 errmsg("publication \"%s\" does not exist",
-						stmt->pubname)));
+		if (!HeapTupleIsValid(tup))
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("publication \"%s\" does not exist",
+							stmt->pubname)));
 
-	pubform = (Form_pg_publication) GETSTRUCT(tup);
+		pubform = (Form_pg_publication) GETSTRUCT(tup);
 
-	/* must be owner */
-	if (!object_ownercheck(PublicationRelationId, pubform->oid, GetUserId()))
-		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
-					   stmt->pubname);
+		/* must be owner */
+		if (!object_ownercheck(PublicationRelationId, pubform->oid,
+							   GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+						   stmt->pubname);
 
-	if (stmt->options)
 		AlterPublicationOptions(pstate, stmt, rel, tup);
+	}
 	else
 	{
 		List	   *relations = NIL;
 		List	   *exceptrelations = NIL;
 		List	   *schemaidlist = NIL;
-		Oid			pubid = pubform->oid;
+		Oid			pubid;
 
-		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
-								   &exceptrelations, &schemaidlist);
+		/*
+		 * Lock the publication so nobody else can do anything with it.
+		 *
+		 * Like RangeVarGetRelidExtended() does for relations, we resolve the
+		 * name, check ownership, and lock inside a loop. If invalidation
+		 * messages arrive (indicating concurrent DDL), we retry. We keep the
+		 * lock held across retries and only release it if the name resolves
+		 * to a different OID on the next iteration.
+		 */
+		{
+			Oid			oldPubId = InvalidOid;
+			bool		retry = false;
 
-		CheckAlterPublication(stmt, tup, relations, schemaidlist);
+			for (;;)
+			{
+				uint64		inval_count = SharedInvalidMessageCounter;
 
-		heap_freetuple(tup);
+				tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+										  CStringGetDatum(stmt->pubname));
 
-		/* Lock the publication so nobody else can do anything with it. */
-		LockDatabaseObject(PublicationRelationId, pubid, 0,
-						   AccessExclusiveLock);
+				if (!HeapTupleIsValid(tup))
+					ereport(ERROR,
+							(errcode(ERRCODE_UNDEFINED_OBJECT),
+							 errmsg("publication \"%s\" does not exist",
+									stmt->pubname)));
 
-		/*
-		 * It is possible that by the time we acquire the lock on publication,
-		 * concurrent DDL has removed it. We can test this by checking the
-		 * existence of publication. We get the tuple again to avoid the risk
-		 * of any publication option getting changed.
-		 */
-		tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
-		if (!HeapTupleIsValid(tup))
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("publication \"%s\" does not exist",
-						   stmt->pubname));
+				pubform = (Form_pg_publication) GETSTRUCT(tup);
+				pubid = pubform->oid;
+
+				if (!object_ownercheck(PublicationRelationId, pubid,
+									   GetUserId()))
+					aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_PUBLICATION,
+								   stmt->pubname);
+
+				if (retry)
+				{
+					if (pubid == oldPubId)
+						break;
+					UnlockDatabaseObject(PublicationRelationId, oldPubId, 0,
+										 AccessExclusiveLock);
+				}
+
+				LockDatabaseObject(PublicationRelationId, pubid, 0,
+								   AccessExclusiveLock);
+
+				if (inval_count == SharedInvalidMessageCounter)
+					break;
+
+				retry = true;
+				oldPubId = pubid;
+				heap_freetuple(tup);
+			}
+		}
+
+		ObjectsInPublicationToOids(stmt->pubobjects, pstate, &relations,
+								   &exceptrelations, &schemaidlist);
+
+		CheckAlterPublication(stmt, tup, relations, schemaidlist);
 
 		relations = list_concat(relations, exceptrelations);
 		AlterPublicationTables(stmt, tup, relations, pstate->p_sourcetext,
-- 
2.34.1


--3eAVwo4vDNlHc8RC--





^ permalink  raw  reply  [nested|flat] 109+ messages in thread