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Re: Optimizer does not follow hint for index forcing (15.7 SP110)

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..Just to add to that.

 

If you specified an index hint on a view it won't work, but it will give you a warning to advise as much.

 

What can happen from time to time is the index hint itself can end up pushing the search engine down a specific path which therefore excludes other indexes at various points of the costing process. I have seen this lead to situations whereby an index hint can lead to plan which uses a non-filtering scan on said index (i.e. a full index scan), whereas without the index hint it uses the very same index but uses a filtering index scan (positioning by key) with an alternate join order.

So I'd say make sure your index hint isn't being used inefficiently, you may be assuming it isn't using it at all.

 

On a related note forceplans can readily be ignored under specific circumstances on versions prior to around 15.5 ESD3/4/5ish (if I recall), but as you are running SP110 that side of things should be OK.


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