RE: Btmap Index

David,

  I do not think that this is correct...

Regards
Rajagopal Venkataramany

• David Wagoner <dwagoner_at_arsenaldigital.com> wrote:
  > The SQL query should have the same column order in
  > the select statement as
  > the order in the bitmap index or it will not use the
  > index.
  >
  >
  > david
  >
  >
  >
  > -----Original Message-----
  > Sent: Monday, January 08, 2001 6:50 PM
  > To: Multiple recipients of list ORACLE-L
  >
  >
  > I ran into a similar problem a while back. If the
  > database is set to use
  > the CBO, it might not use the index. Someone on
  > this list gave a great
  > reason why, perhaps the table is just very small and
  > the CBO just decided to
  > do a full table scan instead. You could use a hint
  > and tell it to use rule
  > based on that query and it will use the index on the
  > where clause. That's
  > what I did. The question is, how big is the table
  > and how much data does it
  > have in it? If it is not a lot, there really is
  > nothing to be concerned
  > about. Oh yeah, and almost 100% positive that there
  > is no setting in the
  > init file for the index.
  > Sincerely,
  > Kevin
  >
  > ----- Original Message -----
  > To: Multiple <mailto:ORACLE-L_at_fatcity.com>
  > recipients of list ORACLE-L
  > Sent: Monday, January 08, 2001 5:45 PM
  >
  > Hi,
  >
  > Is there any init.ora parameter that needs to be
  > turned to activate bitmap
  > indexes?
  > I have a bitmap index on one column C1, but when i
  > examine the explain pan
  > of the
  > query: " select C1, b, c from table TT where C1 in
  > ('dd','ff')" , it looks
  > like it is not using
  > the index but doing a full table scan...
  >
  > thanks
  > -krishna
  >
  > -----Original Message-----
  > Kilchoer
  > Sent: Monday, January 08, 2001 2:01 PM
  > To: Multiple recipients of list ORACLE-L
  >
  >
  >
  > > -----Original Message-----
  > > From: Lisa Yates [ mailto:cosnit_at_creighton.edu
  > <mailto:cosnit_at_creighton.edu> ]
  > > Sent: lundi, 8. janvier 2001 11:27
  > >
  > > Why doesn't this query ever return...
  > >
  > > where run_date = to_date('01-03-2001
  > 16:34:59','mm-dd-yyyy
  > > hh24:mi:ss')
  > >
  > > but this query does....
  > >
  > > where to_char(run_date) =
  > to_char(to_date('01-03-2001
  > > 16:34:59','mm-dd-yyyy hh24:mi:ss'))
  > >
  > > and so does this query....
  > >
  > > where to_char(run_date,'mm-dd-yyyy hh24:mi:ss') =
  > '01-03-2001
  > > 16:34:59'
  >
  > Well, I guess my suggestion that run_date may
  > contain a "BCE" (before common
  > era) date was not the answer to your problem. Maybe
  > I misunderstood the
  > issue. When you say "why doesn't the query ever
  > return", do you mean it
  > returns zero rows, or do you mean that the query is
  > taking an abnormally
  > long time? If it's taking an abnormally long time,
  > an explain plan on the
  > two queries may reveal the cause.
  >
  > Jacques R. Kilchoër
  > (949) 754-8816
  > Quest Software, Inc.
  >
  > 8001 Irvine Center Drive
  > Irvine, California 92618
  > U.S.A.
  > http://www.quest.com <http://www.quest.com>
  >
  >
  

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