Horton

Reset lastOverflowedXid on standby when needed

Alexander Korotkov <akorotkov@postgresql.org>

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Commit: 691c0df73a74786b1704b806132006a5754dff32
Author: Alexander Korotkov <akorotkov@postgresql.org>
Date: 2021-11-06T15:34:23Z
Releases: 11.14 
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