--
"Daniel Morgan" <damorgan_at_exxesolutions.com> wrote in message
news:3EF6183E.1024DA30_at_exxesolutions.com...
> Burton Peltier wrote:
>
> > --
> >
> > "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)
> > >
> > >
>
> I think the real issue is a "DBA" (quote marks intentional) that would put
> something into production without
> first insisting on testing. This is a potentially dangerous person and I'd
be
> thinking CYA every time I did
> anything that interacted with them.
>
I agree and I have been doing that, usually. I didn't think this one thru as
I should have.
Thanks for pointing out the real issue (production change with no testing).
I will put it back to the other DBA to show me proof of no adverse impact
and "some" improvement. Then I will check the results myself.
Also, he and I need to talk about overall work priorities ! ... It just
occurred to me, I cannot believe I almost sound like a manager now - yikes!
:)
> --
> 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 - 16:50:55 CDT
