CREATE TABLE t1 (a int, str varchar(3), b int, c int, z int, y int, x int, r int, s int, t int, d char(4), primary key (a,b), key (z), key(x), key(t));
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 NULL foo foo NULL NULL NULL; Using where; Using index
c r
0 20
2 18
4 16
6 14
8 12
10 10
12 8
14 6
16 4
18 2
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 NULL foo foo NULL NULL NULL; Using where; Using index
c r a b
0 20 10 0
2 18 9 1
4 16 8 2
6 14 7 3
8 12 6 4
10 10 5 5
12 8 4 6
14 6 3 7
16 4 2 8
18 2 1 9
id select_type table type possible_keys key key_len ref rows Extra