RE: Bitmap index or no index?
- From: "Brady, Mark" <Mark.Brady@xxxxxxxxxxxxxxxxx>
- To: "topshot.rhit@xxxxxxxxx" <topshot.rhit@xxxxxxxxx>, "oracle-l@xxxxxxxxxxxxx" <oracle-l@xxxxxxxxxxxxx>
- Date: Mon, 6 Apr 2009 18:03:18 -0400
How many processes simultaneously write to mfgunit and/or the other tables?
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On
Behalf Of Michael Ray
Sent: Monday, April 06, 2009 4:24 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: Bitmap index or no index?
For the following query should I bother with a bitmap index on
backflushed or just go without an index?
select replace(p.item_no, '-'), count(*)
from pumpdata pd, part p, mfgunit m
where pd.mfgunitid = m.mfgunitid and m.backflushed IS NULL
and pd.partid = p.partid and pd.pumpdefectsid=0
group by p.item_no
order by 2;
This is 10.2 with a couple million rows in the mfgunit table. The number
of rows where backflushed is null will be very few FOR the records that
match the join condition with the pumpdata table. Once the records that
match this query are processed, backflushed is set for them. A process
will regularly add new records that will match the query. Looking at the
query I may add a bitmap on pumpdefectsid if it doesn't exist already
since that only has 7 values I think.
--
Sincerely,
Michael Ray
--
//www.freelists.org/webpage/oracle-l
>>> This e-mail and any attachments are confidential, may contain legal,
>>> professional or other privileged information, and are intended solely for
>>> the addressee. If you are not the intended recipient, do not use the
>>> information in this e-mail in any way, delete this e-mail and notify the
>>> sender. CEG-IP1
--
//www.freelists.org/webpage/oracle-l
Other related posts:
