Re: Grumble - is this really the best they can do?

Hi Jared

> where largeTab_id+1 = 13536978456
> Obviously this is what you are referring to.

Yes.

> What is not obvious is why you care.

From a technical perspective: I am surprised that the CBO didn't explore rewriting the predicates to something that could make use of an existing index, with a substantially different cost. It really isn't much to ask. Even in the most trivial didactic code I used to demonstrate the issue, this algebraic reduction did not occur.

From a business perspective: it comes down to response time for a query that is executed many times a day in a data warehousing requirement. It is a response time difference of 'instant' vs. around 90 seconds.

> Is this a canned app written in a sub-optimal manner?
> Sub-optimally generated code?

No and yes. The middleware generating the code ultimately executed is an ERP from .... Oracle Corp.

Mike
http://www.strychnine.co.uk <http://www.strychnine.co.uk/>

> On 16 Jul 2016, at 20:55, Jared Still <jkstill_at_gmail.com> wrote:
>

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