303ba0573c
If vacuum fails to prune a tuple killed before OldestXmin, it will decide to freeze its xmax and later error out in pre-freeze checks. Add a test reproducing this scenario to the recovery suite which creates a table on a primary, updates the table to generate dead tuples for vacuum, and then, during the vacuum, uses a replica to force GlobalVisState->maybe_needed on the primary to move backwards and precede the value of OldestXmin set at the beginning of vacuuming the table. This test is coverage for a case fixed in83c39a1f7f. The test was originally committed to master inaa607980aebut later reverted inefcbb76efedue to test instability. The test requires multiple index passes. In Postgres 17+, vacuum uses a TID store for the dead TIDs that is very space efficient. With the old minimum maintenance_work_mem of 1 MB, it required a large number of dead rows to generate enough dead TIDs to force multiple index vacuuming passes. Once the source code changes were made to allow a minimum maintenance_work_mem value of 64kB, the test could be made much faster and more stable. Author: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: John Naylor <johncnaylorls@gmail.com> Reviewed-by: Peter Geoghegan <pg@bowt.ie> Discussion: https://postgr.es/m/CAAKRu_ZJBkidusDut6i%3DbDCiXzJEp93GC1%2BNFaZt4eqanYF3Kw%40mail.gmail.com Backpatch-through: 17
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/.