Go to file
Tom Lane 529ebb20aa Generate EquivalenceClass members for partitionwise child join rels.
Commit d25ea0127 got rid of what I thought were entirely unnecessary
derived child expressions in EquivalenceClasses for EC members that
mention multiple baserels.  But it turns out that some of the child
expressions that code created are necessary for partitionwise joins,
else we fail to find matching pathkeys for Sort nodes.  (This happens
only for certain shapes of the resulting plan; it may be that
partitionwise aggregation is also necessary to show the failure,
though I'm not sure of that.)

Reverting that commit entirely would be quite painful performance-wise
for large partition sets.  So instead, add code that explicitly
generates child expressions that match only partitionwise child join
rels we have actually generated.

Per report from Justin Pryzby.  (Amit Langote noticed the problem
earlier, though it's not clear if he recognized then that it could
result in a planner error, not merely failure to exploit partitionwise
join, in the code as-committed.)  Back-patch to v12 where commit
d25ea0127 came in.

Amit Langote, with lots of kibitzing from me

Discussion: https://postgr.es/m/CA+HiwqG2WVUGmLJqtR0tPFhniO=H=9qQ+Z3L_ZC+Y3-EVQHFGg@mail.gmail.com
Discussion: https://postgr.es/m/20191011143703.GN10470@telsasoft.com
2019-11-05 11:42:24 -05:00
config Simplify PGAC_STRUCT_TIMEZONE Autoconf macro 2019-10-07 16:47:23 +02:00
contrib Refactor code building relation options 2019-11-05 09:17:05 +09:00
doc Doc: Clarify locks taken when using ALTER TABLE ATTACH PARTITION 2019-11-05 10:32:38 +09:00
src Generate EquivalenceClass members for partitionwise child join rels. 2019-11-05 11:42:24 -05:00
.dir-locals.el Make Emacs perl-mode indent more like perltidy. 2019-01-13 11:32:31 -08:00
.gitattributes Add XSL stylesheet to fix up SVG files 2019-06-19 21:26:42 +02:00
.gitignore Support for optimizing and emitting code in LLVM JIT provider. 2018-03-22 11:05:22 -07:00
COPYRIGHT Update copyright for 2019 2019-01-02 12:44:25 -05:00
GNUmakefile.in Add "headerscheck" script to test header-file compilability under C. 2019-08-19 14:22:56 -04:00
HISTORY Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
Makefile Don't unset MAKEFLAGS in non-GNU Makefile. 2019-06-25 09:36:21 +12:00
README Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
README.git Change documentation references to PG website to use https: not http: 2017-05-20 21:50:47 -04:00
aclocal.m4 Fix configure's AC_CHECK_DECLS tests to work correctly with clang. 2018-11-19 12:01:47 -05:00
configure Use CFLAGS_SL while probing linkability of libperl. 2019-10-21 13:52:25 -04:00
configure.in Use CFLAGS_SL while probing linkability of libperl. 2019-10-21 13:52:25 -04:00

README

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.

PostgreSQL has many language interfaces, many of which are listed here:

	https://www.postgresql.org/download

See the file INSTALL for instructions on how to build and install
PostgreSQL.  That file also lists supported operating systems and
hardware platforms and contains information regarding any other
software packages that are required to build or run the PostgreSQL
system.  Copyright and license information can be found in the
file COPYRIGHT.  A comprehensive documentation set is included in this
distribution; it can be read as described in the installation
instructions.

The latest version of this software may be obtained at
https://www.postgresql.org/download/.  For more information look at our
web site located at https://www.postgresql.org/.