Re: Do indexes matter on db in memory

I would say that even if everything (i/o) took place in memory, an in memory index lookup would be faster than an in memory full table scan due to a lack of an index...A couple of million extra gets might start to make a difference. This execution plan difference might not show up in the real world though in terms of noticeable performance gain or loss...

Adrian...
...yadba

"Connor McDonald" <connor_mcdonald_at_yahoo.com> wrote in message news:38FB0807.ED5_at_yahoo.com...
> ( wrote:
> >
> > We have a heavily used oracle database that is 100MB in size, the amount
 of
> > memory
> > on the server is 1G. The dba says that since the major queries get run
 so
> > often that the data is all in memory and further indexes won't help the
> > performance.
> >
> > Is the true? Can anyone tell me reasons why this might not be the
 optimal
> > way to run a heavily used database.
> >
> > Thanks.
>
> That is a simplification...
>
> Eg
>
> select *
> from tableX, tableY
>
> if both tables are 100M results could result in a 10,000M result set -
> which won't fit into 1G.
>
> HTH
> --
> ===========================================
> Connor McDonald
> http://www.oracledba.co.uk
>
> We are born naked, wet and hungry...then things get worse
Received on Tue Apr 18 2000 - 00:00:00 CDT