public inbox for [email protected]
help / color / mirror / Atom feedFrom: Antonin Houska <[email protected]>
Subject: [PATCH] Do not push the active snapshot for copy_table_data before it's needed.
Date: Fri, 10 Apr 2026 12:17:36 +0200
make_new_heap() can launch parallel workers when building index on TOAST
relation. If the snapshot for copy_table_data() is already the active
snapshot, the workers can incorrectly consider it their transaction snapshot.
---
src/backend/commands/repack.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/src/backend/commands/repack.c b/src/backend/commands/repack.c
index 58e3867246f..08fd132a4e3 100644
--- a/src/backend/commands/repack.c
+++ b/src/backend/commands/repack.c
@@ -1013,8 +1013,6 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
* Wait until the worker has the initial snapshot and retrieve it.
*/
snapshot = get_initial_snapshot(decoding_worker);
-
- PushActiveSnapshot(snapshot);
}
/* for CLUSTER or REPACK USING INDEX, mark the index as the one to use */
@@ -1038,6 +1036,8 @@ rebuild_relation(Relation OldHeap, Relation index, bool verbose,
NewHeap = table_open(OIDNewHeap, NoLock);
/* Copy the heap data into the new table in the desired order */
+ if (snapshot)
+ PushActiveSnapshot(snapshot);
copy_table_data(NewHeap, OldHeap, index, snapshot, verbose,
&swap_toast_by_content, &frozenXid, &cutoffMulti);
--
2.47.3
--=-=-=--
view thread (599+ messages) latest in thread
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: [email protected]
Cc: [email protected]
Subject: Re: [PATCH] Do not push the active snapshot for copy_table_data before it's needed.
In-Reply-To: <no-message-id-1150102@localhost>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox