哪条语句效率更高
两个表TABLE_A,TABLE_B
TABLE_A(A int,B int) --A为KEY
TABLE_B(A int,C char,D int...)
TABLE_A.A为KEY,TABLE_A中每条记录的A字段值,在TABLE_B表中都有对应值,多条。现要选择TABLE_A.A,TABLE_B.C,TABLE_B.D,以下两条语句哪条效率更高?
1、SELECT TABLE_A.A,TABLE_B.C,TABLE_B.D FROM TABLE_A inner join TABLE_B ON TABLE_A.A=TABLE_B.A
2、SELECT TABLE_A.A,TABLE_B.C,TABLE_B.D FROM TABLE_A left outer join TABLE_B ON TABLE_A.A=TABLE_B.A