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pgstat_drop_entry_internal() generates an ERROR if facing a pgstats entry already marked as dropped. With a workload doing a lot of concurrent CALL and DROP/CREATE PROCEDURE, it could be possible for AtEOXact_PgStat_DroppedStats(), that wants to do transactional drops, to find entries that are already dropped, after a commit record has been written. In this case, ERRORs are upgraded to PANIC, taking down the server. This issue is fixed by making pgstat_drop_entry() optionally more tolerant to concurrent drops, adding to the routine a missing_ok option to make some of its callers more tolerant (spoiler: some of the callers want a strict behavior, like replication slots and backend stats). pgstat_drop_entry_internal() cannot be called anymore for an entry marked as dropped, hence its error is replaced by an assertion. Functions are handled as a special case in core; this problem could also apply to custom stats kinds depending on what an extension does. track_functions is costly when enabled (disabled by default), which is perhaps the main reason why this has not be found yet. A similar version of this patch has been proposed by Sami Imseih on a different thread for a feature in development. This version has tweaked here by me for the sake of fixing this issue. Reported-by: zhanglihui <zlh21343@163.com> Author: Sami Imseih <samimseih@gmail.com> Author: Michael Paquier <michael@paquier.xyz> Reviewed-by: Ayush Tiwari <ayushtiwari.slg01@gmail.com> Discussion: https://postgr.es/m/19520-73873648d44793cf@postgresql.org Backpatch-through: 15
PostgreSQL Database Management System
This directory contains the source code distribution of the PostgreSQL database management system.
PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/17/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/17/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.