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Tom Lane 2abfd9d5e9 Second try at fixing O(N^2) problem in foreign key references. This replaces ill-fated commit `5ddc72887a`, which was reverted because it broke active uses of FK cache entries. In this patch, we still do nothing more to invalidatable cache entries than mark them as needing revalidation, so we won't break active uses. To keep down the overhead of InvalidateConstraintCacheCallBack(), keep a list of just the currently-valid cache entries. (The entries are large enough that some added space for list links doesn't seem like a big problem.) This would still be O(N^2) when there are many valid entries, though, so when the list gets too long, just force the "sinval reset" behavior to remove everything from the list. I set the threshold at 1000 entries, somewhat arbitrarily. Possibly that could be fine-tuned later. Another item for future study is whether it's worth adding reference counting so that we could safely remove invalidated entries. As-is, problem cases are likely to end up with large and mostly invalid FK caches. Like the previous attempt, backpatch to 9.3. Jan Wieck and Tom Lane		2015-09-25 13:16:30 -04:00
config	Remove support for Unix systems without the POSIX signal APIs.	2015-08-31 12:56:10 -04:00
contrib	Improve handling of collations in contrib/postgres_fdw.	2015-09-24 12:47:29 -04:00
doc	Docs: fix typo in to_char() example.	2015-09-22 10:40:25 -04:00
src	Second try at fixing O(N^2) problem in foreign key references.	2015-09-25 13:16:30 -04:00
.dir-locals.el	emacs: Set indent-tabs-mode in perl-mode	2015-04-12 23:53:23 -04:00
.gitattributes	Add functions for dealing with PGP armor header lines to pgcrypto.	2014-10-01 16:03:39 +03:00
.gitignore	Add .gitignore entries for AIX-specific intermediate build artifacts.	2015-07-08 20:44:22 -04:00
aclocal.m4	Replace our hacked version of ax_pthread.m4 with latest upstream version.	2015-07-08 20:36:06 +03:00
configure	Remove support for Unix systems without the POSIX signal APIs.	2015-08-31 12:56:10 -04:00
configure.in	Remove support for Unix systems without the POSIX signal APIs.	2015-08-31 12:56:10 -04:00
COPYRIGHT	Update copyright for 2015	2015-01-06 11:43:47 -05:00
GNUmakefile.in	Fix distclean/maintainer-clean targets to remove top-level tmp_install dir.	2015-05-13 18:48:05 -04:00
HISTORY	Improve text of stub HISTORY file.	2014-02-12 18:16:17 -05:00
Makefile	Allow make check in PL directories	2011-02-15 06:52:12 +02:00
README	Don't generate plain-text HISTORY and src/test/regress/README anymore.	2014-02-10 20:48:04 -05:00
README.git	Don't generate plain-text HISTORY and src/test/regress/README anymore.	2014-02-10 20:48:04 -05:00

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:

	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.  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/.