Re: Optimizer for Dataware house applications

From: Loyal Barber <lbarber_at_ix.netcom.com>
Date: 1997/01/16
Message-ID: <32DE3655.5A2@ix.netcom.com>#1/1

Karkala wrote:
>
> I had problems using both the optimizer modes for a dataware house
> application.
> The problem using cost based optimizer is it requires lot of temp
> tablespace to perform the Hash join/Sort-merger join( for 200 gb database
> it needs 200GB TEMP) . When using rule based optimizer, the query is not
> optmized preoperly like choosing the wrong driving table/or wrong indexes.
> All the queries are adhoc in nature and generated by a middleware based on
> the user request, so I can't give the hints/or tune the query.
>
> I am interested to know how this problem is handled and what is the best
> option.
>
> Thanks in advance
>
> Reddy M.

I have heard that the trick is to create views with imbedded hints. I have not tried it or had the problems myself, but you might give this a limited test.

Loyal Received on Thu Jan 16 1997 - 00:00:00 CST