Re: Why does this query need a table access by rowid?

From: Tanel Põder <tanel.poder.003_at_mail.ee>
Date: Fri, 23 Jul 2004 21:17:29 +0300
Message-ID: <357001c470e1$55bf9d30$0a879fd9@porgand>

> 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.

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Received on Fri Jul 23 2004 - 13:14:13 CDT