Re: Performance degradation

Holger,

What do you want to know about my application? It is known application (I just can't say here it's name). It has 600MB of sources? So it is pretty difficult for me to explain here what does it does:-) And I don't think it will help.
The information that I provided here is very simple and should be enough I think, you have 2 inputs:
1. select field1, field2 from mytable where upper(field3)='MYVALUE';

    on start it takes 2-3 seconds and after 2-3 hours it takes 2-3 minutes.
2. after building function based index like following:

   create index my_idx on mytable(upper(field3));    it takes 2-3 seconds on start and also after 2,3,5,10...hours.    No more degradations.

Again I don't looking for solution for my problem, I already solved it.

All I'm asking is why full table scan on large table can cause performance degradation in Oracle.
This is very general question and I don't think it connected to specifically my application.

Thanks,
Maxim. Received on Thu Apr 14 2005 - 07:51:23 CDT