SQL TUNING - Explain Plan

EXPLAIN PLAN COMMAND :

SQL> EXPLAIN 
          PLAN FOR

  2  SELECT *

  3  FROM   emp e, dept d

  4  WHERE  e.deptno = d.deptno

  5  AND    e.ename  = 'SMITH';

 Explained

COMMANDS FOR THE RESULTS OF EXPLAIN PLAN  :

Execute this script :

SQL> @$ORACLE_HOME/rdbms/admin/utlxpls.sql

or execute pl/sql command :

SQL> select plan_table_output from table(dbms_xplan.display());

SQL> select plan_table_output from table(dbms_xplan.display('plan_table',null,'basic +predicate +cost'));