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Tom Lane b22527f29d Fix incorrect declaration of citext's regexp_matches() functions.
These functions should return SETOF TEXT[], like the core functions they
are wrappers for; but they were incorrectly declared as returning just
TEXT[].  This mistake had two results: first, if there was no match you got
a scalar null result, whereas what you should get is an empty set (zero
rows).  Second, the 'g' flag was effectively ignored, since you would get
only one result array even if there were multiple matches, as reported by
Jeff Certain.

While ignoring 'g' is a clear bug, the behavior for no matches might well
have been thought to be the intended behavior by people who hadn't compared
it carefully to the core regexp_matches() functions.  So we should tread
carefully about introducing this change in the back branches.  Still, it
clearly is a bug and so providing some fix is desirable.

After discussion, the conclusion was to introduce the change in a 1.1
version of the citext extension (as we would need to do anyway); 1.0 still
contains the incorrect behavior.  1.1 is the default and only available
version in HEAD, but it is optional in the back branches, where 1.0 remains
the default version.  People wishing to adopt the fix in back branches will
need to explicitly do ALTER EXTENSION citext UPDATE TO '1.1'.  (I also
provided a downgrade script in the back branches, so people could go back
to 1.0 if necessary.)

This should be called out as an incompatible change in the 9.5 release
notes, although we'll also document it in the next set of back-branch
release notes.  The notes should mention that any views or rules that use
citext's regexp_matches() functions will need to be dropped before
upgrading to 1.1, and then recreated again afterwards.

Back-patch to 9.1.  The bug goes all the way back to citext's introduction
in 8.4, but pre-9.1 there is no extension mechanism with which to manage
the change.  Given the lack of previous complaints it seems unnecessary to
change this behavior in 9.0, anyway.
2015-05-05 15:51:22 -04:00
config fix escaping of brackets for m4 broken in b6b2149e48 2015-05-03 09:37:15 -04:00
contrib Fix incorrect declaration of citext's regexp_matches() functions. 2015-05-05 15:51:22 -04:00
doc doc: Update installation instructions for new shared libperl/libpython handling 2015-05-05 14:41:39 -04:00
src Add geometry/range functions to support BRIN inclusion 2015-05-05 15:22:24 -03:00
.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 Improve speed of make check-world 2015-04-23 08:59:52 -04:00
COPYRIGHT Update copyright for 2015 2015-01-06 11:43:47 -05:00
GNUmakefile.in Fix parallel make risk with new check temp-install setup 2015-04-29 20:34:22 -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 Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
configure fix escaping of brackets for m4 broken in b6b2149e48 2015-05-03 09:37:15 -04:00
configure.in Windows also needs an override of the shared libpython detection 2015-05-02 13:23:16 -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/.