elynde 72dec7cd25 Faster Query for Differential Updates ... Summary: The old query was effectively SELECT DISTINCT revision.* FROM `differential_revision` revision JOIN `differential_relationship` relationship ON (relationship.revisionID = revision.id AND relationship.objectPHID in ('PHID-USER-a113b9ae4ee9524d0a20')) OR revision.authorPHID = 'PHID-USER-a113b9ae4ee9524d0a20' LEFT JOIN `differential_viewtime` viewtime ON viewtime.viewerPHID in ('PHID-USER-a113b9ae4ee9524d0a20') AND viewtime.objectPHID = revision.phid AND GREATEST(1304022277, IFNULL(viewtime.viewTime, 0)) < revision.dateModified ORDER BY dateModified DESC; I'm not a db performance expert but it looks like the problem is that we have to scan all revisions mysql> EXPLAIN SELECT DISTINCT revision.* FROM `differential_revision` revision JOIN `differential_relationship` relationship ON (relationship.revisionID = revision.id AND relationship.objectPHID in ('PHID-USER-a113b9ae4ee9524d0a20')) OR revision.authorPHID = 'PHID-USER-a113b9ae4ee9524d0a20' LEFT JOIN `differential_viewtime` viewtime ON viewtime.viewerPHID in ('PHID-USER-a113b9ae4ee9524d0a20') AND viewtime.objectPHID = revision.phid AND GREATEST(1304022277, IFNULL(viewtime.viewTime, 0)) < revision.dateModified ORDER BY dateModified DESC; +----+-------------+--------------+-------+--------------------+------------+---------+-------+--------+------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+--------------+-------+--------------------+------------+---------+-------+--------+------------------------------------+ | 1 | SIMPLE | revision | ALL | PRIMARY,authorPHID | NULL | NULL | NULL | 254127 | Using temporary; Using filesort | | 1 | SIMPLE | viewtime | ref | PRIMARY | PRIMARY | 66 | const | 17 | Distinct | | 1 | SIMPLE | relationship | index | PRIMARY,objectPHID | objectPHID | 72 | NULL | 966900 | Using where; Using index; Distinct | +----+-------------+--------------+-------+--------------------+------------+---------+-------+--------+------------------------------------+ The new query is a lot faster mysql> EXPLAIN SELECT revs.* FROM ( (SELECT revision.* FROM `differential_revision` revision WHERE revision.authorPHID in ('PHID-USER-a113b9ae4ee9524d0a20')) UNION (SELECT revision.* FROM `differential_revision` revision JOIN differential_relationship rel WHERE rel.revisionId = revision.Id AND rel.objectPHID = 'PHID-USER-a113b9ae4ee9524d0a20')) as revs LEFT JOIN `differential_viewtime` viewtime ON viewtime.viewerPHID = 'PHID-USER-a113b9ae4ee9524d0a20' AND viewtime.objectPHID = revs.phid WHERE GREATEST(1304022277, IFNULL(viewtime.viewTime, 0)) < revs.dateModified ORDER BY revs.dateModified; +----+--------------+------------+--------+--------------------+------------+---------+-----------------------------------------+------+--------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+--------------+------------+--------+--------------------+------------+---------+-----------------------------------------+------+--------------------------+ | 1 | PRIMARY | <derived2> | ALL | NULL | NULL | NULL | NULL | 3021 | Using filesort | | 1 | PRIMARY | viewtime | ref | PRIMARY | PRIMARY | 66 | const | 17 | Using where | | 2 | DERIVED | revision | ref | authorPHID | authorPHID | 67 | | 1040 | Using where | | 3 | UNION | rel | ref | PRIMARY,objectPHID | objectPHID | 66 | | 3822 | Using where; Using index | | 3 | UNION | revision | eq_ref | PRIMARY | PRIMARY | 4 | phabricator_differential.rel.revisionID | 1 | | | NULL | UNION RESULT | <union2,3> | ALL | NULL | NULL | NULL | NULL | NULL | | +----+--------------+------------+--------+--------------------+------------+---------+-----------------------------------------+------+--------------------------+ Test Plan: Loaded differential updates with new query, made sure page loaded quickly. Ran the query from the command-line, it took about .4 seconds. Reviewed By: Girish Reviewers: tuomaspelkonen, jungejason, Girish Commenters: btrahan CC: aran, btrahan, elynde, Girish Differential Revision: 181		2011-05-03 15:00:46 -07:00
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__init__.php	Differential Updates View	2011-04-28 14:40:41 -07:00
DifferentialRevisionListData.php	Faster Query for Differential Updates	2011-05-03 15:00:46 -07:00