Re: Performance like against = (equal sign)

Hi Sybrand ,

meanwhile did I find the reason (because of your hint). The problem has been a not valid or existing primary key. Additionally there existed duplicate records.
After deleting the record and creating the primary index any problems has been aware.

The only thing what I do not understand, how could it happen that the primary key did not exists? I created the database using the Data-Export/Import facilities of Oracle 7.3.3 Ent.Mgr. For the time being it looks, that the imporrt or the export did not handled this primary key

Regards
Nicolas Bronke

> Please post the explain plan results and we may be able to find out what
> happened.
>
> > Normally I thought, Oracle optimize the select statements, so that
oracle
> > replace the like statement with the equal sign if possible. But now I
> > mentioned on a database 8.04 how slow it could be.
> >
> > It was a view (not very complex) where the master table has around 7000
> rows
> > and the detail around 130 rows).
> > a select count(*) from this view was unbelieveable slow.
> >
> > The same view on my other database (Ora 7.3.3) and with more than 16000
> rows
> > returns the answer immediatly.
> >
> > Then I replaced the like statement with the equal sign. Now Oracle 8.04
> runs
> > quickly too.
> >
> > Did I misunderstand something?
> >
> > Regards
> > Nicolas Bronke
> >
> >
> >
>
>
Received on Tue Oct 19 1999 - 10:01:56 CDT