Merge lp:~wgrant/launchpad/bpn-spn-trgm-index into lp:launchpad

[William Grant]

Add trigram indices on BinaryPackageName and SourcePackageName, to satisfy %foo% matches.

My trigram index experiment on the sacrificial DistributionSourcePackageCache table worked fine, so let's expand it to SourcePackageName and BinaryPackageName. This is mostly to optimise the exact_match=False variants of getPublishedSources and getPublishedBinaries, taking a problematic example from ~200ms to 10ms.

[Stuart Bishop (stub)]

Looks good.

We probably want to use __trgm as the index name suffix to avoid colliding with our existing crappy naming conventions.

review: Approve (db)

[Stuart Bishop (stub)]

Applied to production

=== added file 'database/schema/patch-2209-23-1.sql'
--- database/schema/patch-2209-23-1.sql	1970-01-01 00:00:00 +0000
+++ database/schema/patch-2209-23-1.sql	2012-09-07 04:34:22 +0000
@@ -0,0 +1,11 @@
+-- Copyright 2012 Canonical Ltd.  This software is licensed under the
+-- GNU Affero General Public License version 3 (see the file LICENSE).
+
+SET client_min_messages=ERROR;
+
+CREATE INDEX binarypackagename__name__trgm ON binarypackagename
+    USING gin (name trgm.gin_trgm_ops);
+CREATE INDEX sourcepackagename__name__trgm ON sourcepackagename
+    USING gin (name trgm.gin_trgm_ops);
+
+INSERT INTO LaunchpadDatabaseRevision VALUES (2209, 23, 1);