345
342
INSERT INTO t1 VALUES (1,1), (2,1), (3,1);
346
343
EXPLAIN SELECT DISTINCT a FROM t1;
347
344
EXPLAIN SELECT DISTINCT a,b FROM t1;
349
345
EXPLAIN SELECT DISTINCT t1_1.a, t1_1.b FROM t1 t1_1, t1 t1_2;
351
346
EXPLAIN SELECT DISTINCT t1_1.a, t1_1.b FROM t1 t1_1, t1 t1_2
353
348
EXPLAIN SELECT a FROM t1 GROUP BY a;