Commit Graph

12 Commits

Author SHA1 Message Date
Tom Lane
6f5b8beb64 Make contrib/pg_trgm also support regex searches with GiST indexes.
This wasn't addressed in the original patch, but it doesn't take very
much additional code to cover the case, so let's get it done.

Since pg_trgm 1.1 hasn't been released yet, I just changed the definition
of what's in it, rather than inventing a 1.2.
2013-04-10 13:31:02 -04:00
Tom Lane
3ccae48f44 Support indexing of regular-expression searches in contrib/pg_trgm.
This works by extracting trigrams from the given regular expression,
in generally the same spirit as the previously-existing support for
LIKE searches, though of course the details are far more complicated.

Currently, only GIN indexes are supported.  We might be able to make
it work with GiST indexes later.

The implementation includes adding API functions to backend/regex/
to provide a view of the search NFA created from a regular expression.
These functions are meant to be generic enough to be supportable in
a standalone version of the regex library, should that ever happen.

Alexander Korotkov, reviewed by Heikki Linnakangas and Tom Lane
2013-04-09 01:06:54 -04:00
Tom Lane
9728eda792 Fix contrib/pg_trgm's similarity() function for trigram-free strings.
Cases such as similarity('', '') produced a NaN result due to computing
0/0.  Per discussion, make it return zero instead.

This appears to be the basic cause of bug #7867 from Michele Baravalle,
although it remains unclear why her installation doesn't think Cyrillic
letters are letters.

Back-patch to all active branches.
2013-02-13 14:07:06 -05:00
Tom Lane
b2a01b9ad1 Fix bugs in contrib/pg_trgm's LIKE pattern analysis code.
Extraction of trigrams did not process LIKE escape sequences properly,
leading to possible misidentification of trigrams near escapes, resulting
in incorrect index search results.

Fujii Masao
2012-08-20 13:25:42 -04:00
Tom Lane
629b3af27d Convert contrib modules to use the extension facility.
This isn't fully tested as yet, in particular I'm not sure that the
"foo--unpackaged--1.0.sql" scripts are OK.  But it's time to get some
buildfarm cycles on it.

sepgsql is not converted to an extension, mainly because it seems to
require a very nonstandard installation process.

Dimitri Fontaine and Tom Lane
2011-02-13 22:54:49 -05:00
Tom Lane
6e2f3ae884 Support LIKE and ILIKE index searches via contrib/pg_trgm indexes.
Unlike Btree-based LIKE optimization, this works for non-left-anchored
search patterns.  The effectiveness of the search depends on how many
trigrams can be extracted from the pattern.  (The worst case, with no
trigrams, degrades to a full-table scan, so this isn't a panacea.  But
it can be very useful.)

Alexander Korotkov, reviewed by Jan Urbanski
2011-01-31 21:34:49 -05:00
Tom Lane
b525bf771e Add KNNGIST support to contrib/pg_trgm.
Teodor Sigaev, with some revision by Tom
2010-12-04 00:16:21 -05:00
Tom Lane
30e2c42e00 Fix a few contrib regression test scripts that hadn't gotten the word
about best practice for including the module creation scripts: to wit
that you should suppress NOTICE messages.  This avoids creating
regression failures by adding or removing comment lines in the module
scripts.
2007-11-13 06:29:04 +00:00
Bruce Momjian
33e2e02493 Add CVS version labels to all install/uninstall scripts. 2007-11-13 04:24:29 +00:00
Bruce Momjian
47fe868831 Adjust pg_trgm expected output for new *.sql file. 2007-11-11 03:57:06 +00:00
Teodor Sigaev
15f91f2789 Add GIN support for pg_trgm. From Guillaume Smet <guillaume.smet@gmail.com>
with minor editorization by me.
2007-03-14 14:15:40 +00:00
Teodor Sigaev
cbfa4092bb trgm - Trigram matching for PostgreSQL
--------------------------------------

	The pg_trgm contrib module provides functions and index classes
	for determining the similarity of text based on trigram
	matching.
2004-05-31 17:18:12 +00:00