3409b4db63
This test case turns out to depend on the assumption that a non-Var subquery output that's underneath an outer join will always get wrapped in a PlaceHolderVar. But that behavior causes performance regressions in some cases compared to what happened before v16. The next commit will avoid inserting a PHV in the same cases where pre-v16 did, and that causes get_memoized_path to not detect that a memoize plan could be used. Commit this separately, in hopes that we can restore the test after making get_memoized_path smarter. (It's failing to find memoize plans in adjacent cases where no PHV was ever inserted, so there is definitely room for improvement there.) Discussion: https://postgr.es/m/CAG1ps1xvnTZceKK24OUfMKLPvDP2vjT-d+F2AOCWbw_v3KeEgg@mail.gmail.com
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/.