EXPLAIN SELECT `test_versions`.* FROM `test_versions` WHERE (`test_versions`.test_id IN (363,534,271,274,365,390,404,405,406,407,409,182,201,1386,1387,1388,1389,1390,1307,1308,1309,1310,1311,424,423,393,361,357,355,353,352,351,350,347,209,339,340,345,223,305,66,307,303,221,227,228,229,230,231,210,214,215,217,218,219,234,235,236,237,238,239,232,233,212,100,59))
Id select_type table type possible_keys key key_len ref row Extra
'1', 'SIMPLE', 'test_versions', 'ALL', 'fk_test_versions_on_test_id', NULL, NULL, NULL, '76', 'Using where; Using filesort'
It's not using indexing which is already specified. I don't want to pass USE INDEX explicitly. What's the problem with this query ?