Re: Cost based optimizer

From: <markp7832_at_my-deja.com>
Date: Mon, 01 Nov 1999 17:39:42 GMT
Message-ID: <7vkj8t$avv$1@nnrp1.deja.com>

In article <7vkflp$860$1_at_nnrp1.deja.com>, Stanislav Benda <si_bendovi_at_hotmail.com> wrote:
> Does anybody use cost based optimizer, hints, table statistics and
> histograms? It is at least 7 years old technology and seems to be
> ignored. I will appereciate any feedback.
> Please reply to me ( sender) as well,
>
> Stan
>

We have been relying on the cost based optimizer since version 7.0. It works reasonably well, but you still have to tune. The tuning rules just changed. Many vendor packages were and still are not coded properly for the optimizer. We however have recently purchased a system where it appears every SQL statement is hinted to run as the vendor thinks it should run.

I would recommend you always use a sample size to analyze your objects, and to determine the proper frequency for re-analyzing each of your tables.

--
Mark D. Powell -- The only advice that counts is the advice that you follow so follow your own advice --

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Before you buy. Received on Mon Nov 01 1999 - 11:39:42 CST