797e9ea6e5
Previous commit fixed a bug where VACUUM would truncate the CLOG that's still needed to check the commit status of XIDs in the async notify queue, but as mentioned in the commit message, it wasn't a full fix. If a backend is executing asyncQueueReadAllNotifications() and has just made a local copy of an async SLRU page which contains old XIDs, vacuum can concurrently truncate the CLOG covering those XIDs, and the backend still gets an error when it calls TransactionIdDidCommit() on those XIDs in the local copy. This commit fixes that race condition. To fix, hold the SLRU bank lock across the TransactionIdDidCommit() calls in NOTIFY processing. Per Tom Lane's idea. Backpatch to all supported versions. Reviewed-by: Joel Jacobson <joel@compiler.org> Reviewed-by: Arseniy Mukhin <arseniy.mukhin.dev@gmail.com> Discussion: https://www.postgresql.org/message-id/2759499.1761756503@sss.pgh.pa.us Backpatch-through: 14
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/devel/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/devel/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/.