This chapter explains some key logic rewrites to help you understand how TiDB generates the final query plan. For example, when you execute the
select * from t where t.a in (select t1.a from t1 where t1.b=t.b) query in TiDB, you will find that the
t.a in (select t1.a from t1 where t1.b=t.b) does not exist because TiDB has made some rewrites here.
This chapter introduces the following key rewrites: