Bitmap index and perfomance

From: Alexander <Alexander_Ryabikov_at_dialogbank.com>
Date: 1998/03/23
Message-ID: <351688C0.BF36A855@dialogbank.com>#1/1

Hi,
I have performance problem with tables that have at least one bitmap index.

Example (very simple):
TABLE 1
CREATE TABLE table1 (

    id NUMBER PRIMARY KEY,
    status CHAR(1)
);
CREATE BITMAP INDEX i_table1_status ON table1 ( status );

Queries like "SELECT * FROM table1 WHERE status 'A' " work propertly, but if I want

    "SELECT * FROM table1 ORDER BY id" oracle choose :

            SELECT STATEMENT
                SORT (Order By)
                TABLE ACCESS BY ROWID
table1
                    BITMAP CONVERSION (TO ROWIDS)
                        BITMAP INDEX (FULL SCAN)

i_table1_status

and select works 5-6 min ( 60000 rows).

Oracle: 7.3.3.4. I tried on SUN and HP. Optimizer mode : first_rows
v733_plans_enabled = true

Someone knows what the problem might be?

Thanks in advance.

Alexander
aryabikov_at_dialogbank.com Received on Mon Mar 23 1998 - 00:00:00 CST