Re: Tunning question

From: Adon Keber <adon_at_cool.iskon.local>
Date: 16 Sep 2003 08:19:18 GMT
Message-ID: <slrnbmdhs6.1pc.adon@cool.iskon.local>

On Mon, 15 Sep 2003 20:28:08 +0300, Tanel Poder wrote:
>> Elapsed: 00:03:183.84
>> Elapsed: 00:01:116.47
>
>Hm, since when is there over 60 seconds in a minute?
>Posting your query and execution plans would be helpful.
>

Well, it seems it is a 'feature' in sqlplus. Number of seconds (eg. 183) is total number of seconds elapsed.

Query is quite complex involving views and quite a few tables and execution plan is also large. But the key difference in execution plans is in only one place where there is the choice between two indexes.
Optimizer chooses 'wrong' index and it takes 2 minutes longer than when the 'right' index is choosen.
So my problem isn't query optimization. I just want optimizer to 'realize' the right execution plan.

My key question is how faster query could have so much larger values for execution statistics (especially physical reads) than slower query. Because then I'll probably understand why the optimizer makes the wrong choice.

a. Received on Tue Sep 16 2003 - 03:19:18 CDT