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Tom Lane 647fd9a108 Fix two bugs induced in VACUUM FULL by async-commit patch.
First, we cannot assume that XLogAsyncCommitFlush guarantees hint bits will be
settable, because clog.c's inexact LSN bookkeeping results in windows where a
previously flushed transaction is considered unhintable because it shares an
LSN slot with a later unflushed transaction.  But repair_frag requires
XMIN_COMMITTED to be correct so that it can distinguish tuples moved by the
current vacuum.  Since not being able to set the bit is an uncommon corner
case, the most practical way of dealing with it seems to be to abandon
shrinking (ie, don't invoke repair_frag) when we find a non-dead tuple whose
XMIN_COMMITTED bit couldn't be set.

Second, it is possible for the same reason that a RECENTLY_DEAD tuple does not
get its XMAX_COMMITTED bit set during scan_heap.  But by the time repair_frag
examines the tuple it might be possible to set the bit.  We therefore must
take buffer content lock when calling HeapTupleSatisfiesVacuum a second time,
else we can get an Assert failure in SetBufferCommitInfoNeedsSave.  This
latter bug is latent in existing releases, but I think it cannot actually
occur without async commit, since the first HeapTupleSatisfiesVacuum call
should always have set the bit.  So I'm not going to back-patch it.

In passing, reduce the existing "cannot shrink relation" messages from NOTICE
to LOG level.  The new message must be no higher than LOG if we don't want
unpredictable regression test failures, and consistency seems like a good
idea.  Also arrange that only one such message is reported per VACUUM FULL;
in typical scenarios you could get spammed with many such messages, which
seems a bit useless.
2007-08-13 19:08:26 +00:00
config Fix search for SGML stylesheets to include the place where Gentoo keeps them. 2007-08-09 02:33:58 +00:00
contrib Arrange to put TOAST tables belonging to temporary tables into special schemas 2007-07-25 22:16:18 +00:00
doc Document that the regexp split functions ignore zero-length matches in 2007-08-13 01:18:47 +00:00
src Fix two bugs induced in VACUUM FULL by async-commit patch. 2007-08-13 19:08:26 +00:00
COPYRIGHT Update CVS HEAD for 2007 copyright. Back branches are typically not 2007-01-05 22:20:05 +00:00
GNUmakefile.in Replace useless uses of := by = in makefiles. 2007-02-09 15:56:00 +00:00
Makefile Remove remains of old depend target. 2007-01-20 17:16:17 +00:00
README Fix spectacular misspellings of procedural language names 2006-07-24 16:55:59 +00:00
README.CVS Some further editorializing on README.CVS. 2004-03-28 06:09:08 +00:00
aclocal.m4 Add new auto-detection of thread flags. 2004-04-23 18:15:55 +00:00
configure Fix search for SGML stylesheets to include the place where Gentoo keeps them. 2007-08-09 02:33:58 +00:00
configure.in Adjust configure so that it sets CFLAGS properly for Intel's icc 2007-08-05 15:43:00 +00:00

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 including some of the more
common listed below:

C++ - http://thaiopensource.org/development/libpqxx/
JDBC - http://jdbc.postgresql.org
ODBC - http://odbc.postgresql.org
Perl - http://search.cpan.org/~dbdpg/
PHP - http://www.php.net
Python - http://www.initd.org/
Ruby - http://ruby.scripting.ca/postgres/

Other language binding are available from a variety of contributing
parties.

PostgreSQL also has a great number of procedural languages available,
a short but not complete list is below:

PL/pgSQL - included in PostgreSQL source distribution
PL/Perl - included in PostgreSQL source distribution
PL/PHP - http://projects.commandprompt.com/projects/public/plphp
PL/Python - included in PostgreSQL source distribution
PL/Java - http://gborg.postgresql.org/project/pljava/projdisplay.php
PL/Tcl - included in PostgreSQL source distribution

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/.