oracle优化sql的explain for plan

3.12使用 EXPLAIN PLAN FOR查看执行计划

使用 explain plan for查看执行计划，用法如下explain plan for s0L语句;

select from table(dbms xplan display)，示例( Oraclellgr2，scot账户)如下。SOL＞ explain plan for select ename， deptno

2 from emp

3 where deptno in (select deptno from dept where dname= 'CHICAGO');

explained

SOL> select from table(dbms xplan.display);

PLAN TABLE OUTPUT