12 Replies Latest reply: May 16, 2008 2:47 PM by Amit_DBA RSS

    How to read a Explain Plan

    Saaz Ena
      I work with Oracle 10g and New to Explain plan. I am using PL/SQL Developer 7 to connect to DB.

      I have a SQL statements

      SQL> Select * from emp where sal > 15000

      When I see the plan table I find column COST , CARDINATILY, and BYTES.
      with some values.

      Please I would be greatful if someone would explain me HOW can One judge the performance for the query looking at these Columns.

      What these column tell us.

      Thanks and Regards
      Saaz