diff options
| author | Tom Lane | 2008-04-14 17:05:34 +0000 |
|---|---|---|
| committer | Tom Lane | 2008-04-14 17:05:34 +0000 |
| commit | 9b5c8d45f62bd3d243a40cc84deb93893f2f5122 (patch) | |
| tree | 2d75607f7bdb96cfa1d73a3a36a4b3328118ff08 /doc/src/sgml/gist.sgml | |
| parent | 10be77c173211a75718f50fe6061862f6a0cb4a2 (diff) | |
Push index operator lossiness determination down to GIST/GIN opclass
"consistent" functions, and remove pg_amop.opreqcheck, as per recent
discussion. The main immediate benefit of this is that we no longer need
8.3's ugly hack of requiring @@@ rather than @@ to test weight-using tsquery
searches on GIN indexes. In future it should be possible to optimize some
other queries better than is done now, by detecting at runtime whether the
index match is exact or not.
Tom Lane, after an idea of Heikki's, and with some help from Teodor.
Diffstat (limited to 'doc/src/sgml/gist.sgml')
| -rw-r--r-- | doc/src/sgml/gist.sgml | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/doc/src/sgml/gist.sgml b/doc/src/sgml/gist.sgml index 587517da1d1..f236e6ad614 100644 --- a/doc/src/sgml/gist.sgml +++ b/doc/src/sgml/gist.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/gist.sgml,v 1.29 2007/11/13 23:36:26 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/gist.sgml,v 1.30 2008/04/14 17:05:32 tgl Exp $ --> <chapter id="GiST"> <title>GiST Indexes</title> @@ -103,7 +103,10 @@ Given a predicate <literal>p</literal> on a tree page, and a user query, <literal>q</literal>, this method will return false if it is certain that both <literal>p</literal> and <literal>q</literal> cannot - be true for a given data item. + be true for a given data item. For a true result, a + <literal>recheck</> flag must also be returned; this indicates whether + the predicate implies the query (<literal>recheck</> = false) or + not (<literal>recheck</> = true). </para> </listitem> </varlistentry> |