One optimization I see quickly is changing the left join to an inner join. You always look for records that exist in tag_ad_map (by checking for tm.is_active) so the left join is not necessary. That should at least speed this query up considerably.
Walter Need MySQL advice? OlinData.com is the place to go! (http://www.olindata.com) SELECT COUNT(*) antal,ad.ad_id FROM ad > > LEFT JOIN tag_ad_map tm ON tm.ad_id=ad.ad_id > > WHERE > > tm.tag_id IN (99, 10807, 20728, 21, 135) > > AND ad.is_removed = 0 AND ad.is_active=1 AND (ad.ant_feedback_alert <= 5 OR > ad.whitelisted = 1) > > AND tm.is_active=1 AND ad.ad_id != 32793 > > GROUP BY tm.ad_id ORDER BY antal DESC LIMIT 10 > >
