agora inbox for pgsql-committers@postgresql.org  
help / color / mirror / Atom feed
pgsql: Update FSM in COPY FREEZE replay
2+ messages / 1 participants
[nested] [flat]

* pgsql: Update FSM in COPY FREEZE replay
@ 2026-09-14 15:59  Melanie Plageman <melanieplageman@gmail.com>
  0 siblings, 0 replies; 2+ messages in thread

From: Melanie Plageman @ 2026-09-14 15:59 UTC (permalink / raw)
  To: pgsql-committers@lists.postgresql.org

Update FSM in COPY FREEZE replay

d96f87332b3 folded COPY FREEZE visibility map updates into
XLOG_HEAP2_MULTI_INSERT records. Unlike the former XLOG_HEAP2_VISIBLE
redo path, multi-insert redo only updated the FSM when the record did
not contain a heap page FPI and the heap page had less than 20% free
space.

This can leave all-frozen pages with missing or stale FSM entries on a
standby. After promotion, vacuum will skip those pages, preventing
their free space from being discovered.

When a multi-insert record sets the page all-frozen, record the heap
page's free space unconditionally.

Reported-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/CAAKRu_bS3nfMJCF2fjE%2Bceb5-t%3D2p_VPMk2PWuVomrOFxg5DGQ%40mail.gmail.com
Backpatch-through: 19

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/f7700080dc4c9226dd0fd81795214c02635e474d

Modified Files
--------------
src/backend/access/heap/heapam_xlog.c | 46 ++++++++++++++++++++++++-----------
1 file changed, 32 insertions(+), 14 deletions(-)



^ permalink  raw  reply  [nested|flat] 2+ messages in thread

* pgsql: Update FSM in COPY FREEZE replay
@ 2026-09-14 16:00  Melanie Plageman <melanieplageman@gmail.com>
  0 siblings, 0 replies; 2+ messages in thread

From: Melanie Plageman @ 2026-09-14 16:00 UTC (permalink / raw)
  To: pgsql-committers@lists.postgresql.org

Update FSM in COPY FREEZE replay

d96f87332b3 folded COPY FREEZE visibility map updates into
XLOG_HEAP2_MULTI_INSERT records. Unlike the former XLOG_HEAP2_VISIBLE
redo path, multi-insert redo only updated the FSM when the record did
not contain a heap page FPI and the heap page had less than 20% free
space.

This can leave all-frozen pages with missing or stale FSM entries on a
standby. After promotion, vacuum will skip those pages, preventing
their free space from being discovered.

When a multi-insert record sets the page all-frozen, record the heap
page's free space unconditionally.

Reported-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/CAAKRu_bS3nfMJCF2fjE%2Bceb5-t%3D2p_VPMk2PWuVomrOFxg5DGQ%40mail.gmail.com
Backpatch-through: 19

Branch
------
REL_19_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/f4b511ae93a587982ac025c7a2512586fe87489d

Modified Files
--------------
src/backend/access/heap/heapam_xlog.c | 46 ++++++++++++++++++++++++-----------
1 file changed, 32 insertions(+), 14 deletions(-)



^ permalink  raw  reply  [nested|flat] 2+ messages in thread


end of thread, other threads:[~2026-09-14 16:00 UTC | newest]

Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2026-09-14 15:59 pgsql: Update FSM in COPY FREEZE replay Melanie Plageman <melanieplageman@gmail.com>
2026-09-14 16:00 pgsql: Update FSM in COPY FREEZE replay Melanie Plageman <melanieplageman@gmail.com>

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox