Alibabacloud, Database, Query Optimization, Sql, Relational Databases.
correlated parts and simplify the query. The following part is a simple example. Select t1.c2 From t1 Where t1.c3 < ( Select min(t2.c3) From t2 Where t1.c1 = t2.c1 group by t1.c1 ) -- Replace t1.ct with t2.c1 in subquery for simplification Select t1.c2 From t1 Where t1.c3 < ( Select min(t2.c3) From