Re: About Oracle Bitmap Index...

Stanley wrote:

> Daniel Morgan <damorgan_at_exxesolutions.com> wrote in message news:<3EC074A0.568ABBAE_at_exxesolutions.com>...
> > Stanley wrote:
> >
> > > 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);
> >
> > Please please tell me you did not create a table with a column of type
> > ROWID. Please!
> >
> > Have you invested any time in researching when to use, and when not to
> > indexes? Especially bitmap indexes? What you posted looks like the
> > poster-child for a bad example.

>


> Hi, buddy:

>     The example that I wrote above is just for experiment, not for using actually.


When you experiment do you read documentation first or just hack away until things break?

When you experiment do you do so with a purpose or just to break things?

The table design is non-relational, the number of indexes insane, and the result predictable.

Whack away if you wish but do understand that you have zero chance of creating anything useful in the vein in which you are mining.

--
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)