Oracle8 Reverse Indexes Problem

Hi all,

We did the follow test in Oracle 8.0.5:

create table t3 (
col1 varchar2(10) primary key,
col2 varchar2(10));

insert into t3 values ('1','12134');
insert into t3 values ('2','14123');
insert into t3 values ('3','19769');

create index ind_col2_t3 on t3(col2);

truncate table plan_table;
explain plan for select * from t3 where col2='22222'; select operation,options,object_name from plan_table;

OPERATION OPTIONS OBJECT_NAME
-------------------- -------------------- ------------------------------
SELECT STATEMENT

TABLE ACCESS         BY INDEX ROWID       T3
INDEX                RANGE SCAN           IND_COL2_T3

Ok!!!

drop index ind_col2_t3;
create index ind_col2_t3 on t3(col2) reverse;

truncate table plan_table;
explain plan for select * from t3 where col2='22222'; select operation,options,object_name from plan_table; OPERATION OPTIONS OBJECT_NAME
-------------------- -------------------- ------------------------------
SELECT STATEMENT

TABLE ACCESS         FULL                 T3

Why the Oracle RDBMS didn't use "ind_col2_t3" reverse index? My select statment uses an equality expression in where clause.

Thanks in advance,

Alexandre Leite
leite_alexandre_at_hotmail.com Received on Sat Mar 27 1999 - 18:14:17 CST