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Re: Optimizer not pushing filters down into view

From: <mccmx_at_hotmail.com>
Date: 23 Aug 2006 10:01:06 -0700
Message-ID: <1156352466.493786.314240@b28g2000cwb.googlegroups.com>


>
> General clues:
>
> The predicates you supplied can be propagated
> and moved by transitive closure, but I can't tell
> whether that's relevant because you have to look
> at the dbms_xplan() output to see what predicates
> Oracle is using. Note particularly that your join
> predicate CAN disappear, or be supplemented by
> an extra constant predicate.
>

Jonathan,

I appreciate you taking a look at this, thanks.

I think you've hit the nail on the head.... When you mentioned transitive closure you got me thinking.

I first tried running the query with a join condition which differed from the filter condition. This pushed the filters down into the table.

So I now have a workaround which is to add a ||'' (i.e. a null string) to the end of each joined column.

This fixes the issue (as a workaround).

I'm still waiting for Oracle support to tell me whether this is a bug or a 'feature'.

Thanks very much for your time.

Matt Received on Wed Aug 23 2006 - 12:01:06 CDT

Original text of this message

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