Re: explain plan changes if using bind vars

On Wed, 03 Aug 2005 04:16:51 GMT, Mladen Gogala <gogala_at_sbcglobal.net> wrote:

>On Tue, 02 Aug 2005 16:40:57 +0000, NetComrade wrote:
>
>> I have a query that changes explain plan for the worse if I change
>> non-bind vars to bind vars. Discovered this yesterday, when was trying
>> to figure out extra dblink chatter (see reduce dblink (database link)
>> chatter thread)
>
>Things usually develop from bad to worse, as is clearly explained here:
>http://www.cpuidle.de/murphy.shtml
>If everything looks good, you overlooked something.
>
>For bad cases like your query, there are hints which will probably do the
>trick. CBO is not bulletproof and there are cases when you must use hints
>to get the desired results. That's what they're here for.

I wish there was a hint to make the query execute subquery remotedly, and don't bother trying to figure out the explain plan.. I couldn't figure out how to do that..

We did find a solution (as Frank suggested) where we both simplified a query, and hid it with a view on the remote site.

.......
We use Oracle 8.1.7.4 and 9.2.0.5 on Solaris 2.7 boxes remove NSPAM to email Received on Wed Aug 03 2005 - 15:34:09 CDT