Re: performance problem

You created an index on a varchar2 field. If this field is the field "number" you use in your query it's possible that Oracle converts your select in

    .... where to_number(number) = 100 ... and so oracle doesn't uses the index.

GDN Klaus Hümmeler <khuemmeler_at_delphinsys.de> wrote in article <35696D47.AA701111_at_delphinsys.de>...
> Hi,
>
> I'm testing the performance of an Oracle8 evaluating version. Therefor I
> created a table with nearly 20000 rows containing 180 MB of data (number
> and varchar2).
> I made an primary index of one Column (varchar2) wich contains the
> entry-number.
>
> Every question like e.g. "select * from MaschDat where number = 100"
> takes
> nearly 2 Minutes until I get the selected row(s).
>
> Is Oracle really so slow, or what is my mistake??? The System, where
> Oracle is running, is an NT-Server with 200 MHz Pentium an 64 MB Ram.
>
> Please give me a hint for solving this problem!
>
> Regards Klaus
>
> ---
> Dipl.-Ing. Klaus Huemmeler
> Delphin Prozesstechnik
> 51515 Kürten / Germany
> EMail: khuemmeler_at_delphinsys.de
>
>
>
Received on Mon May 25 1998 - 15:03:38 CDT