--
"Daniel Morgan" <damorgan_at_exxesolutions.com> wrote in message
news:3EF5E5E0.9C09012A_at_exxesolutions.com...
> Burton Peltier wrote:
>
> > Just looking for opinions... I have my own and another DBA I work with
has
> > his opinion. Looking for some other opinions...
> >
> > Some info on setup first...
> >
> > - SunFire V880 8x900MHz CPUs
> > - 16Gig Memory
> > - 3 databases
> > - db1 - 360M SGA - 5 Gig allocated space
> > - db2 - 1200M SGA - 55Gig allocated space
> > - db3 - 1200M SGA - 60Gig allocated space
> > - all of these SGAs are mostly allocated to db buffers, but all have
over
> > 100 meg for shared pool
> > - all in archive log mode
> > - nothing else runs on this machine except these 3 Oracle databases and
only
> > DBAs login
> > - all version 8.1.7.4
> >
> > Scenario: Suppose you have a small table less than 1Meg (.82) that is
> > queried 140,000 times a day on db2. The table currently has no index,
and
> > the query runs in less than 1 second (100Msecs) when the server is idle
(no
> > other activity).
> >
> > Question: Would you put an index to improve the 1 query to improve
averall
> > system usage?
> >
> > My opinion is the table is so small , if it isn't always cached, then it
> > should be forced to be cached.
> >
> > Other DBA's opinion is to add a combo-index on the 2 columns queried in
this
> > 1 query.
> >
> > Note: I am not sure of other usage of this table. There could be other
> > querys on other columns or a lot of inserts ... not sure right now.
> >
> > --
>
> Not a question that can be answered theoretically.
>
> If you are DBAs (I'm not questioning that you are) ... why didn't you just
test
> it rather than trying to intellectually puzzle out an answer?
>
Basically, the other DBA is asking me to put the index - without testing.
Then, I asked this group a question that as you have pointed out - really
cannot be answered here... requires testing. My mistake for asking.
As others have pointed out (and I was thinking about), it could actually
increase logical I/Os which would not be good and this will have to be
tested.
> --
> Daniel Morgan
> http://www.outreach.washington.edu/extinfo/certprog/oad/oad_crs.asp
> damorgan_at_x.washington.edu
> (replace 'x' with a 'u' to reply)
>
>
Received on Sun Jun 22 2003 - 15:26:26 CDT
