I'm executing the following query SELECT COUNT(*) FROM table WHERE field1='value' AND (field2 = 1000 OR field3 = 2000) There is one index over field1 and another composited over field2&field3. I see MySQL always selects the field1 index and then makes a join using the other two fields which is quite bad because it needs to join 146.000 rows. Suggestions on how to improve this? Thanks