Base de données relationnelle
Find a file
Robert Haas 806f9b3d76 Avoid useless respawining the autovacuum launcher at high speed.
When (1) autovacuum = off and (2) there's at least one database with
an XID age greater than autovacuum_freeze_max_age and (3) all tables
in that database that need vacuuming are already being processed by a
worker and (4) the autovacuum launcher is started, a kind of infinite
loop occurs.  The launcher starts a worker and immediately exits.  The
worker, finding no worker to do, immediately starts the launcher,
supposedly so that the next database can be processed.  But because
datfrozenxid for that database hasn't been advanced yet, the new
worker gets put right back into the same database as the old one,
where it once again starts the launcher and exits.  High-speed ping
pong ensues.

There are several possible ways to break the cycle; this seems like
the safest one.

Amit Khandekar (code) and Robert Haas (comments), reviewed by
Álvaro Herrera.

Discussion: http://postgr.es/m/CAJ3gD9eWejf72HKquKSzax0r+epS=nAbQKNnykkMA0E8c+rMDg@mail.gmail.com
2017-01-20 16:16:46 -05:00
config Fix configure's incorrect version tests for flex and perl. 2016-05-02 11:18:11 -04:00
contrib Invalidate cached plans on FDW option changes. 2017-01-06 14:12:52 -05:00
doc Update copyright for 2017 2017-01-03 12:37:53 -05:00
src Avoid useless respawining the autovacuum launcher at high speed. 2017-01-20 16:16:46 -05:00
.dir-locals.el Update Emacs configuration 2013-08-13 20:08:44 -04:00
.gitattributes gitattributes: Ignore time zone data files for whitespace checks 2014-07-22 00:12:28 -04:00
.gitignore Add *.pot to .gitignore 2013-10-19 10:56:52 -04:00
aclocal.m4 Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
configure Stamp 9.4.10. 2016-10-24 16:12:53 -04:00
configure.in Stamp 9.4.10. 2016-10-24 16:12:53 -04:00
COPYRIGHT Update copyright for 2017 2017-01-03 12:37:53 -05:00
GNUmakefile.in Add TAP tests for client programs 2014-04-14 21:33:46 -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

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/.