| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
 |
 | |||
| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
|
| |||
Home -> Community -> Mailing Lists -> Oracle-L -> RE: Why does this query need a table access by rowid?
Thanks to Jonathan, Karen, and Tanel.
Tanel, that was my first thought when I read the explanation. I'm = already building the suggested index, and I'm confident it will solve = the problem.
Thanks again, all.
-Mark
Mark J. Bobak
Oracle DBA
ProQuest Company
Ann Arbor, MI
"Post Hoc Ergo Propter Hoc"
-----Original Message-----
From: oracle-l-bounce_at_freelists.org =
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Tanel P=F5der
Sent: Friday, July 23, 2004 2:17 PM
To: oracle-l_at_freelists.org
Subject: Re: Why does this query need a table access by rowid?
> So, the index is recognized, and that's great. My question is, why is
> the TABLE ACCESS BY ROWID required?
> Since only the DOC_ID is in the select list, why the table access?
Since in the index you don't have the DOC_ID column, you have only the function of DOC_ID in your index and Oracle isn't smart enough to look inside the function to see whether the funcion leaves the value = unaltered...
Try to do a composite index on f(doc_id), doc_id.
Tanel.
-- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html ----------------------------------------------------------------- ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request_at_freelists.org put 'unsubscribe' in the subject line. -- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------Received on Fri Jul 23 2004 - 13:18:14 CDT
 |
 |