Re: Explain Plan Gives 0 Cost.

From: Joe Nardone <joe_at_access4.digex.net>
Date: 1995/09/23
Message-ID: <440435$h30_at_news4.digex.net>#1/1


Charles Dye (PC) (Charles_Dye_at_corp.dialog.com) wrote:
:
: SQL> explain plan
: 2 for
: 3 select a.username, a.user_id, b.profile
: 4 from a, b
: 5 where a.user_id = b.user_id
: 6 and b.created < sysdate
: 7 and b.profile != 'DEFAULT'
: 8 /
:
: Explained.
:
: SQL> select id, parent_id, position
: 2 from plan_table;
:
: ID PARENT_ID POSITION
: ---------- ---------- ----------
: 0 <<<<< Null here corresponds to Cost = 0
: 1 0 0
: 2 1 1
: 3 2 1
: 4 1 2
: 5 4 1

A null cost for the query comes up when running the rule based optimizer. When running cost based, you'd get a cost for the query.

Joe

:
: 6 rows selected.
:
 

-- 
                                   
=------------------------------------------------------------------------=
Joe Nardone               |    
joe_at_access.digex.net      |
Received on Sat Sep 23 1995 - 00:00:00 CEST

Original text of this message