Stuart Bishop has proposed merging lp:~stub/launchpad/pending-db-changes into lp:launchpad/db-devel.
Requested reviews: Launchpad code reviewers (launchpad-reviewers) For more details, see: https://code.launchpad.net/~stub/launchpad/pending-db-changes/+merge/93213 = Summary = wgrant identified a query chewing up excessive time in the planner. Approx. 30ms is spent per 100 samples in the planner, adding up since the default was 2500. == Proposed fix == Lowering the collected statistics on one column works around the issue. This should stop these particular timeouts while I assemble a test case to pass upstream. == Pre-implementation notes == == Implementation details == == Tests == == Demo and Q/A == = Launchpad lint = Checking for conflicts and issues in changed files. Linting changed files: database/schema/patch-2209-00-7.sql == Schema == database/sampledata/current.sql database/sampledata/lintdata.sql differs from database/sampledata/current.sql. Patches to the schema, or manual edits to database/sampledata/current.sql do not match the dump of the launchpad_ftest_template database. If database/sampledata/lintdata.sql is correct, copy it to database/sampledata/current.sql. Otherwise update database/sampledata/current.sql and run: make schema make newsampledata cd database/sampledata cp newsampledata.sql database/sampledata/current.sql Run make schema again to update the test/dev database. database/sampledata/current.sql database/sampledata/lintdata-dev.sql differs from database/sampledata/current-dev.sql. Patches to the schema, or manual edits to database/sampledata/current-dev.sql do not match the dump of the launchpad_dev_template database. If database/sampledata/lintdata-dev.sql is correct, copy it to database/sampledata/current-dev.sql. Otherwise update database/sampledata/current-dev.sql and run: make schema make newsampledata cd database/sampledata cp newsampledata-dev.sql database/sampledata/current-dev.sql Run make schema again to update the test/dev database. -- https://code.launchpad.net/~stub/launchpad/pending-db-changes/+merge/93213 Your team Launchpad code reviewers is requested to review the proposed merge of lp:~stub/launchpad/pending-db-changes into lp:launchpad/db-devel.
=== added file 'database/schema/patch-2209-00-7.sql' --- database/schema/patch-2209-00-7.sql 1970-01-01 00:00:00 +0000 +++ database/schema/patch-2209-00-7.sql 2012-02-15 14:42:30 +0000 @@ -0,0 +1,7 @@ +SET client_min_messages=ERROR; + +-- Lower gathered statistics on this column to work around extreme planning +-- times issue being investigated. +ALTER TABLE TeamMembership ALTER person SET STATISTICS 100; + +INSERT INTO LaunchpadDatabaseRevision VALUES (2209, 00, 7);
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