Re: Performance With Multiple Users

There is one cpu, and all users query the same table.

We've tried with a multi-processor machine, and found that each additional user's processing time is spread across the processors. So the result is something like:

# users, time per user

1, 1s
2, 1s
3, 1s
4, 1s
5, 1.25s
6, 1.5s
7, 1.75s
8, 1.8s

Salaam

In article <9015r9$deq$1_at_nnrp1.deja.com>,   Alex Filonov <afilonov_at_pro-ns.net> wrote:
> In article <8vmn64$gpc$1_at_nnrp1.deja.com>,
> yitbsal_at_statcan.ca wrote:
> > Server Specs:
> > Sun Sparc Ultra-450
> > 3072MB RAM
> > 8207MB virtual memory
> > Oracle 8i
> >
> > The performance of our Oracle database seems to degrade abnormally
 as
> > the number of concurrent users increases. For example, the following
> > query:
> >
> > SELECT *
> > FROM MYTABLE
> > WHERE MYCOL1 = 10010;
> >
> > runs in 1 second with 1 user, 2 seconds each for 2 users, 3 seconds
> > each for 3 users, etc. (These are rough figures). The query is
 tuned to
> > run in the most optimal manner, using an index.
> >
> > Table MYTABLE has 50,000,000 rows.
> > It's primary key is (MYCOL1,MYCOL2).
> > It has about a hundred partitions by MYCOL1.
> >
> > I realize I haven't given detailed information, but I'm not looking
 for
> > precise answers. Can anyone speculate about why performance might
> > degrade so rapidly with increasing number of users?
> >
> > Can you please also give me some idea of how your systems fare as
 the
> > number of concurrent users increases?
> >
> > Thanks,
> > Salaam Yitbarek
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
> >
>
> Couple of questions:
>
> 1. How many CPUs on the machine?
> 2. Do all users query the same table when performance degrades?
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>

Sent via Deja.com http://www.deja.com/
Before you buy. Received on Wed Nov 29 2000 - 15:21:04 CST