an set statement_id = '=' for
select ename from emp e
where mgr = (select empno from emp where ename = 'KING');
explain plan set statement_id = 'JOIN1' for
select e1.ename from emp e1,emp e2
where e1.mgr = e2.empno
and e2.ename = 'KING';
REM -- find employees with greater than average salaries
explain plan set statement_id = '>' for
select ename from emp e where e.sal > (select avg(sal) from emp);
explain plan set statement_id = 'JOIN2' for
select e1.ename from emp e1,(select avg(sal) sal from emp) e2
where e1.页码：[1] [2] [3] [4] [5] [6] [7] [8] 第7页、共8页 |
