Re: Many tables in a view.

Are your joins simple joins?

If so then if some of the tables being joined are selection and some are control table result joins, then investigate whether the selection/navigation joins can be better served via in clauses and exists/notexists.

Similarly, some of the control table result joins may be removed by embedding in-line views of compound joins to achieve the same results.

If you are able to use in clauses based on highly selective access paths then you should be able to "encourage" the optimiser along the best execution plan.

Rod

-- 
Rod Corderey

Lane Associates
RodCorderey_at_Lane-Associates.com
http://www.Lane-Associates.com

Jack van Zanen wrote:


> 

> 

> 

> Hi All

> 

> I have a question:

> 

> If we join 11 tables in a view the performance of a select on that view will

> drop dramatically compared to 10 tables in the join.

> I have heard something about this being a optimizer issue that does not really

> like this many tables in a join.

> 

> What are the possible solutions to make these querries run better??

> 

> Jack

> 

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> Author: Jack van Zanen

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