Go to file
Kevin Grittner 7c3e8039f4 Add a few entries to the tail of time mapping, to see old values.
Without a few entries beyond old_snapshot_threshold, the lookup
would often fail, resulting in the more aggressive pruning or
vacuum being skipped often enough to matter.  This was very clearly
shown by a python test script posted by Ants Aasma, and was likely
a factor in an earlier but somewhat less clear-cut test case posted
by Jeff Janes.

This patch makes no change to the logic, per se -- it just makes
the array of mapping entries big enough to make lookup misses based
on timing much less likely.  An occasional miss is still possible
if a thread stalls for more than 10 minutes, but that does not
create any problem with correctness of behavior.  Besides, if
things are so busy that a thread is stalling for more than 10
minutes, it is probably OK to skip the more aggressive cleanup at
that particular point in time.
2016-04-29 16:46:08 -05:00
config Copyedit comments and documentation. 2016-04-01 21:53:10 -04:00
contrib Revert "Convert contrib/seg's bool-returning SQL functions to V1 call convention." 2016-04-28 11:46:07 -04:00
doc doc: Minor wording changes 2016-04-29 13:03:58 -04:00
src Add a few entries to the tail of time mapping, to see old values. 2016-04-29 16:46:08 -05:00
.dir-locals.el emacs: Set indent-tabs-mode in perl-mode 2015-04-12 23:53:23 -04:00
.gitattributes Fix whitespace and remove obsolete gitattributes entry 2016-03-13 16:03:13 -04:00
.gitignore Add .gitignore entries for AIX-specific intermediate build artifacts. 2015-07-08 20:44:22 -04:00
COPYRIGHT Update copyright for 2016 2016-01-02 13:33:40 -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
aclocal.m4 Replace our hacked version of ax_pthread.m4 with latest upstream version. 2015-07-08 20:36:06 +03:00
configure Add BSD authentication method. 2016-04-08 13:52:06 -04:00
configure.in Add BSD authentication method. 2016-04-08 13:52:06 -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:

	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/.