1975
1975
EXPLAIN SELECT a FROM t1 WHERE a='AA' GROUP BY a;
1976
1976
id select_type table type possible_keys key key_len ref rows Extra
1978
1978
EXPLAIN SELECT a FROM t1 WHERE a='BB' GROUP BY a;
1979
1979
id select_type table type possible_keys key key_len ref rows Extra
1980
1980
1 SIMPLE t1 ref PRIMARY PRIMARY 22 const 1 Using where; Using index