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Re: Cost based optimizer

From: GDN <gert.deneve_at_advalvas.be>
Date: Tue, 9 Nov 1999 21:02:01 +0100
Message-ID: <809ukr$q0h$1@news1.skynet.be>


Do not forget to 'analyze' !

Gert

jobrien99_at_my-deja.com wrote in message <80565a$vbn$1_at_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?
>
>Yep, people use'em.
>
>> It is at least 7 years old technology and seems to be
>> ignored. I will appereciate any feedback.
>
>Feedback would be. I run it and then look at tkprof output and tune
>individual statements where the optimizer got it wrong, or the coder
>got it wrong. Hints are a very powerful way to make sql fly.
>I've run in both modes and noted which is better at what statements.
>
>As far as computing the statistics, play with the percentage argument
>in the analyze command. I prefer estimate as I think it accurate enough
>for me and takes way less time. Anybody doubt this then run tests and
>review the values in all_objects.
>
>As far as a text I like Harrisons SQL book by Prentice Hall.
>
>Oracle version can be important.
>
>Regards,
>John
>
>> Please reply to me ( sender) as well,
>>
>> Stan
>>
>> Sent via Deja.com http://www.deja.com/
>> Before you buy.
>>
>
>
>Sent via Deja.com http://www.deja.com/
>Before you buy.
Received on Tue Nov 09 1999 - 14:02:01 CST

Original text of this message

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