Bitmap indexes

From: Janek A. <anisimowicz_at_poczta.onet.pl>
Date: Thu, 15 Mar 2001 12:01:59 +0100
Message-ID: <98q7f5$odb$1@sunsite.icm.edu.pl>

I have big (40 mln records) partitioned table (about 40 partitions). I added 2 bitmap indexes for fields with low cardinality (5 to 10 different values). When I try to load next volume of data to this table my loading process takes longer time. Of course, I know that when I add new indexes loading process takes more time, but I show an example. Example:
- Without 2 bitmap indexes: a portion of data (100.000 records) takes: 6
minuts
- With 2 bitmap indexes: a portion of data (100.000 records) takes: 10
hours!!!

When I remove this indexes loading process takes 6 minuts again

I check this situations on servers: 8.0.5, 8.0.6, 8.1.6 and the problem occurs.

Create index example:
CREATE BITMAP INDEX IDX_BI1_I ON MY_TABLE (MY_FIELD)
PCTFREE 1
STORAGE
(
INITIAL 10M
NEXT 10M
PCTINCREASE 0
MINEXTENTS 1
MAXEXTENTS 5000
)
TABLESPACE IDX1
LOCAL
NOLOGGING
/

Thanx,

Janek A. Received on Thu Mar 15 2001 - 05:01:59 CST