About Oracle Bitmap Index...

From: Stanley <chiujen.lin_at_msa.hinet.net>
Date: 12 May 2003 20:59:04 -0700
Message-ID: <ebf3513d.0305121959.3bc5d527@posting.google.com>

I create many Bitmap Indices on all attributes of a table which has about 100 attributes(A1~A100). I query data and use hint on it, when the Where clause including some of attributes of A1 to A50, it is good to work, but when the Where clause including some of attributes of A51 to A100, it's performance will
be very poor, why ???

Oracle version : 9.0.1.0.0
O.S : Windows XP
RAM : 1G
HD : 10G

Create table sample :

CREATE TABLE "FUZZY"."FEMALE_BI" (
"RID" ROWID NOT NULL,
"AB1_1" NUMBER(1, 0) NOT NULL,

:
"AB1_100" NUMBER(1, 0) NOT NULL)
Create Bitmap Index sample :

  Create Bitmap Index B11 on Female_BI (AB1_1) TABLESPACE FB_INDEX STORAGE ( INITIAL 1000K);
     :
  Create Bitmap Index B1100 on Female_BI(AB1_100) TABLESPACE FB_INDEX STORAGE ( INITIAL 1000K); Received on Mon May 12 2003 - 22:59:04 CDT