Re: Cost based optimizer

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 Mon Nov 08 1999 - 00:00:00 CET