EVOLUTION-MANAGER

Edit File: table_elim_debug.result

drop table if exists t1, t2; create table t1 (a int); insert into t1 values (0),(1),(2),(3); create table t2 (a int primary key, b int) as select a, a as b from t1 where a in (1,2); explain select t1.a from t1 left join t2 on t2.a=t1.a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 4 set optimizer_switch='table_elimination=off'; explain select t1.a from t1 left join t2 on t2.a=t1.a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 4 1 SIMPLE t2 eq_ref PRIMARY PRIMARY 4 test.t1.a 1 Using where; Using index set optimizer_switch='table_elimination=on'; explain select t1.a from t1 left join t2 on t2.a=t1.a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 4 set optimizer_switch='table_elimination=default'; explain select t1.a from t1 left join t2 on t2.a=t1.a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 4 drop table t1, t2;