pgsql: Fix incorrect WAL description for PREPARE TRANSACTION record. - Mailing list pgsql-committers

From Fujii Masao
Subject pgsql: Fix incorrect WAL description for PREPARE TRANSACTION record.
Date
Msg-id E1uHZeq-0003YS-1D@gemulon.postgresql.org
Whole thread Raw
List pgsql-committers
Fix incorrect WAL description for PREPARE TRANSACTION record.

Since commit 8b1dccd37c7, the PREPARE TRANSACTION WAL record includes
information about dropped statistics entries. However, the WAL resource
manager description function for PREPARE TRANSACTION record failed to
parse this information correctly and always assumed there were
no such entries.

As a result, for example, pg_waldump could not display the dropped
statistics entries stored in PREPARE TRANSACTION records.

The root cause was that ParsePrepareRecord() did not set the number of
statistics entries to drop on commit or abort. These values remained
zero-initialized and were never updated from the parsed record.

This commit fixes the issue by properly setting those values during parsing.
With this fix, pg_waldump can now correctly report dropped statistics
entries in PREPARE TRANSACTION records.

Back-patch to v15, where commit 8b1dccd37c7 was introduced.

Author: Daniil Davydov <3danissimo@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CAJDiXgh-6Epb2XiJe4uL0zF-cf0_s_7Lw1TfEHDMLzYjEmfGOw@mail.gmail.com
Backpatch-through: 15

Branch
------
REL_15_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/0e0174b4973af2982498c33f7911312250b330ca

Modified Files
--------------
src/backend/access/rmgrdesc/xactdesc.c | 2 ++
1 file changed, 2 insertions(+)


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