Re: Performance estimation

<kal121_at_my-deja.com> wrote in message news:8rdls3$iho$1_at_nnrp1.deja.com...

> Yes, these are two very different subjects. But getting back to the
> original question, you can't use an excel spreadsheet to determine
> query performance. However, you can use tools, such as OEM's
> Performance Pack, Quest's SQL Expert, Lecco, TKPROF, set autotrace on,
> etc to determine query performance. I've used Performance Pack's Tuning
> Pack and I find it very useful. TKPROF has better accuracy however but
> it's harder to use. Pick your tradeoffs.

I'm not sure that this *exactly* answers the original question. Things like Oracle Expert, TKPROF our old friend explain plan etc are helpful but they are mostly after the fact. I.E they tell you how a query is performing and point you at optimisations. They don't do things like estimated execution time etc and like Brian I can't really see how they could. I can't answer for SQL Expert and Lecco because I've never used them. Then of course there is the way the CBO will change its mind as statistics change. Mind you it looks like we are buying a product whose suppliers 'guarantee' a response time under 5 seconds - even for ad-hoc & free text queries by end users.This I can't wait to see.

--
Niall Litchfield
Oracle DBA
Audit Commission UK