Merge lp:~wgrant/launchpad/dspc-trgm-indices into lp:launchpad

[William Grant]

Add indices to optimise the new version of Distribution.searchSourcePackageCaches.

This branch adds three indices to SourcePackagePublishingHistory and DistributionSourcePackageCache. They're all to make the new Distribution.searchSourcePackageCaches query in lp:~wgrant/launchpad/package-search-timeouts nice and fast.

The existing GiST FTI index is being replaced with a faster GIN one. name gets a trigram index so LIKE '%foo%' is fast. SPPH gets a new compound index.

[Stuart Bishop (stub)]

review: Approve (db)

[Stuart Bishop (stub)]

Applied to production

=== added file 'database/schema/patch-2209-23-0.sql'
--- database/schema/patch-2209-23-0.sql	1970-01-01 00:00:00 +0000
+++ database/schema/patch-2209-23-0.sql	2012-06-13 11:05:31 +0000
@@ -0,0 +1,14 @@
+-- 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 SCHEMA trgm;
+CREATE EXTENSION pg_trgm WITH SCHEMA trgm;
+
+CREATE INDEX distributionsourcepackagecache__name__idx
+    ON distributionsourcepackagecache USING gin (name trgm.gin_trgm_ops);
+CREATE INDEX sourcepackagepublishinghistory__archive__distroseries__spn__status__idx
+    ON sourcepackagepublishinghistory (archive, distroseries, sourcepackagename, status);
+
+INSERT INTO LaunchpadDatabaseRevision VALUES (2209, 23, 0);