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Tom Lane 0816fad6ee Undo 8.4-era lobotomization of subquery pullup rules.
After the planner was fixed to convert some IN/EXISTS subqueries into
semijoins or antijoins, we had to prevent it from doing that in some
cases where the plans risked getting much worse.  The reason the plans
got worse was that in the unoptimized implementation, subqueries could
reference parameters from the outer query at any join level, and so
full table scans could be avoided even if they were one or more levels
of join below where the semi/anti join would be.  Now that we have
sufficient mechanism in the planner to handle such cases properly,
it should no longer be necessary to play dumb here.

This reverts commits 07b9936a0f and
cd1f0d04bf.  The latter was a stopgap
fix that wasn't really sufficiently analyzed at the time.  Rather
than just restricting ourselves to cases where the new join can be
stacked on the right-hand input, we should also consider whether it
can be stacked on the left-hand input.
2012-01-27 19:46:41 -05:00
config Enable compiling with the mingw-w64 32 bit compiler. 2011-12-10 15:35:41 -05:00
contrib Fix pg_upgrade --help text for --user to not use a plural cluster name. 2012-01-26 22:18:58 -05:00
doc Use parameterized paths to generate inner indexscans more flexibly. 2012-01-27 19:26:38 -05:00
src Undo 8.4-era lobotomization of subquery pullup rules. 2012-01-27 19:46:41 -05:00
.gitignore Add gitignore for mingw/cygwin build outputs 2011-06-09 18:11:47 +02:00
aclocal.m4 Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
configure Use __sync_lock_test_and_set() for spinlocks on ARM, if available. 2012-01-07 15:38:52 -05:00
configure.in Use __sync_lock_test_and_set() for spinlocks on ARM, if available. 2012-01-07 15:38:52 -05:00
COPYRIGHT Update copyright notices for year 2012. 2012-01-01 18:01:58 -05:00
GNUmakefile.in Build src/ before contrib/ in make world 2011-08-24 21:34:49 +03:00
Makefile Allow make check in PL directories 2011-02-15 06:52:12 +02:00
README Remove useless whitespace at end of lines 2010-11-23 22:34:55 +02:00
README.git Trivial typo fix. 2010-09-21 14:16:00 -04:00

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:

	http://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.  Changes between all PostgreSQL releases are recorded in the
file HISTORY.  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
http://www.postgresql.org/download/.  For more information look at our
web site located at http://www.postgresql.org/.