Horton

Reset lastOverflowedXid on standby when needed

Alexander Korotkov <akorotkov@postgresql.org>

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Commit: e1fee28a0441652f021045646808a772314798f9
Author: Alexander Korotkov <akorotkov@postgresql.org>
Date: 2021-11-06T15:34:19Z
Releases: 13.5 
Reset lastOverflowedXid on standby when needed

Currently, lastOverflowedXid is never reset.  It's just adjusted on new
transactions known to be overflowed.  But if there are no overflowed
transactions for a long time, snapshots could be mistakenly marked as
suboverflowed due to wraparound.

This commit fixes this issue by resetting lastOverflowedXid when needed
altogether with KnownAssignedXids.

Backpatch to all supported versions.

Reported-by: Stan Hu
Discussion: https://postgr.es/m/CAMBWrQ%3DFp5UAsU_nATY7EMY7NHczG4-DTDU%3DmCvBQZAQ6wa2xQ%40mail.gmail.com
Author: Kyotaro Horiguchi, Alexander Korotkov
Reviewed-by: Stan Hu, Simon Riggs, Nikolay Samokhvalov, Andrey Borodin, Dmitry Dolgov

Files

PathChange+/−
src/backend/storage/ipc/procarray.c modified +19 −2

Discussion