67a54b9e83
In some cases, we may want to transfer a HAVING clause into WHERE in hopes of eliminating tuples before aggregation instead of after. Previously, we couldn't do this if there were any nonempty grouping sets, because we didn't have a way to tell if the HAVING clause referenced any columns that were nullable by the grouping sets, and moving such a clause into WHERE could potentially change the results. Now, with expressions marked nullable by grouping sets with the RT index of the RTE_GROUP RTE, it is much easier to identify those clauses that reference any nullable-by-grouping-sets columns: we just need to check if the RT index of the RTE_GROUP RTE is present in the clause. For other HAVING clauses, they can be safely pushed down. Author: Richard Guo Discussion: https://postgr.es/m/CAMbWs4-NpzPgtKU=hgnvyn+J-GanxQCjrUi7piNzZ=upiCV=2Q@mail.gmail.com |
||
|---|---|---|
| .github | ||
| config | ||
| contrib | ||
| doc | ||
| src | ||
| .cirrus.star | ||
| .cirrus.tasks.yml | ||
| .cirrus.yml | ||
| .dir-locals.el | ||
| .editorconfig | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| 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/.