Re: Performance degradation

<zabutimaxim_at_gmail.com> wrote in message news:1113398176.019624.6030_at_f14g2000cwb.googlegroups.com...
> Hi,
>
> I have a huge performance degradation on Oracle side
> of my Web application. I found that problem come from select
> statement from table with above 1.5 millions records with
> "where condition" that contains function "upper", like following:
>
> select field1, field2 from mytable where upper(field3)='MYVALUE';
>
> I solved this problem by adding function based index for
> field3, but I still don't understand why this cause to
> degradation? I mean why right after restart of Oracle server this
> select runs for 5-10 seconds, but after 2-3 hours the same select
> statement runs for 2-3 minutes?
>
> I have Orcale 9.2.0.6.0 installed on Windows 2003 Server.
> 2 CPU 2.4 GHZ and 2GB RAM.
>
> Thanks,
> Maxim.
>

What is the load on the server ? Memory usage, I/O swapping, CPU load ... If the query runs very fast after a server restart but very slow after several hours, I supect a heavy load on the server at that time.

Matthias Received on Wed Apr 13 2005 - 13:38:26 CDT