https://bugzilla.wikimedia.org/show_bug.cgi?id=57175
Web browser: --- Bug ID: 57175 Summary: SpecialRecentChanges::doMainQuery query needs tuning Product: MediaWiki Version: 1.21.3 Hardware: All OS: All Status: NEW Severity: major Priority: Unprioritized Component: Database Assignee: wikibugs-l@lists.wikimedia.org Reporter: sprin...@wikimedia.org Classification: Unclassified Mobile Platform: --- The following query is much slower on MariaDB enwiki with the FORCE INDEX than without it: SELECT /* SpecialRecentChanges::doMainQuery */ rc_id,rc_timestamp,rc_cur_time,rc_user,rc_user_text,rc_namespace,rc_title,rc_comment,rc_minor,rc_bot,rc_new,rc_cur_id,rc_this_oldid,rc_last_oldid,rc_type,rc_source,rc_patrolled,rc_ip,rc_old_len,rc_new_len,rc_deleted,rc_logid,rc_log_type,rc_log_action,rc_params,wl_user,wl_notificationtimestamp,ts_tags,fp_stable,fp_pending_since FROM `recentchanges` FORCE INDEX (rc_timestamp) LEFT JOIN `watchlist` ON (wl_user = '12744321' AND (wl_title=rc_title) AND (wl_namespace=rc_namespace)) LEFT JOIN `tag_summary` ON ((ts_rc_id=rc_id)) LEFT JOIN `flaggedpages` ON ((fp_page_id = rc_cur_id)) WHERE (rc_timestamp >= '20131018000000') AND rc_bot = '0' AND (rc_namespace = '828') AND (rc_type != 5) AND rc_new IN ('0','1') ORDER BY rc_timestamp DESC LIMIT 500 With force: > 1 minute, a slow range scan on rc_timestamp, ~2 million rows. Without force: < 3 seconds, a fast ref lookup on rc_namespace_title with cheap filesort, ~1000 rows. -- You are receiving this mail because: You are the assignee for the bug. You are on the CC list for the bug. _______________________________________________ Wikibugs-l mailing list Wikibugs-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikibugs-l