c1408956e3
When pulling up a subquery, its targetlist items may be wrapped in PlaceHolderVars to enforce separate identity or as a result of outer joins. This causes any upper-level WHERE clauses referencing these outputs to contain PlaceHolderVars, which prevents partprune.c from recognizing that they match partition key columns, defeating partition pruning. To fix, strip PlaceHolderVars from operands before comparing them to partition keys. A PlaceHolderVar with empty phnullingrels appearing in a relation-scan-level expression is effectively a no-op, so stripping it is safe. This parallels the existing treatment in indxpath.c for index matching. In passing, rename strip_phvs_in_index_operand() to strip_noop_phvs() and move it from indxpath.c to placeholder.c, since it is now a general-purpose utility used by both index matching and partition pruning code. Back-patch to v18. Although this issue exists before that, changes in that version made it common enough to notice. Given the lack of field reports for older versions, I am not back-patching further. In the v18 back-patch, strip_phvs_in_index_operand() is retained as a thin wrapper around the new strip_noop_phvs() to avoid breaking third-party extensions that may reference it. Reported-by: Cándido Antonio Martínez Descalzo <candido@ninehq.com> Diagnosed-by: David Rowley <dgrowleyml@gmail.com> Author: Richard Guo <guofenglinux@gmail.com> Discussion: https://postgr.es/m/CAH5YaUwVUWETTyVECTnhs7C=CVwi+uMSQH=cOkwAUqMdvXdwWA@mail.gmail.com Backpatch-through: 18 |
||
|---|---|---|
| .github | ||
| config | ||
| contrib | ||
| doc | ||
| src | ||
| .cirrus.star | ||
| .cirrus.tasks.yml | ||
| .cirrus.yml | ||
| .dir-locals.el | ||
| .editorconfig | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| aclocal.m4 | ||
| configure | ||
| configure.ac | ||
| COPYRIGHT | ||
| GNUmakefile.in | ||
| HISTORY | ||
| Makefile | ||
| meson.build | ||
| meson_options.txt | ||
| README.md | ||
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/.