Thread: pgsql: Reset lastOverflowedXid on standby when needed

pgsql: Reset lastOverflowedXid on standby when needed

From
Alexander Korotkov
Date:
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

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/05e6e78c1840d07154a4b52092178a2d1ad39445

Modified Files
--------------
src/backend/storage/ipc/procarray.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)