Go to file
Simon Riggs efc16ea520 Allow read only connections during recovery, known as Hot Standby.
Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record.

New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far.

This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required.

Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit.

Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 01:32:45 +00:00
config Python 3 support in PL/Python 2009-12-15 22:59:55 +00:00
contrib Add a hook to let loadable modules get control at ProcessUtility execution, 2009-12-15 20:04:49 +00:00
doc Allow read only connections during recovery, known as Hot Standby. 2009-12-19 01:32:45 +00:00
src Allow read only connections during recovery, known as Hot Standby. 2009-12-19 01:32:45 +00:00
aclocal.m4 Add new auto-detection of thread flags. 2004-04-23 18:15:55 +00:00
configure Python 3 support in PL/Python 2009-12-15 22:59:55 +00:00
configure.in Properly define ENABLE_THREAD_SAFETY in conflgure, per suggestion from Peter. 2009-12-11 02:21:21 +00:00
COPYRIGHT Update copyright for 2009. 2009-01-01 17:24:05 +00:00
GNUmakefile.in Build bzip2 tarball in dist target as well 2009-11-03 21:28:10 +00:00
Makefile Remove remains of old depend target. 2007-01-20 17:16:17 +00:00
README Point to our download URL, rather than listing interface in the README 2008-05-06 22:02:12 +00:00
README.CVS Fix the makefiles to fail cleanly if Perl is needed but not present. This 2009-06-23 03:46:00 +00:00

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/.