Index on date field

Question

Please see my table
create table DATE_TEST
  ID         VARCHAR2(6) not null,
  ID_DESC    VARCHAR2(250),
  START_DATE DATE,
  END_DATE   DATE
-- Create/Recreate primary, unique and foreign key constraints
alter table DATE_TEST
  add constraint DATE_TEST_PK primary key (ID);
-- Create/Recreate indexes
create index DATE_TEST_IDX1 on DATE_TEST (END_DATE));
create index DATE_TEST_IDX2 on DATE_TEST (START_DATE);No I added some data into table.My problem is it is not taking index for between query.
EXPLAIN PLAN FOR SELECT * FROM       DATE_TEST WHERE           start_date between to_date('01/01/2012','DD/MM/YYYY') AND to_date('31/12/2012','DD/MM/YYYY')           OR  end_date between to_date('01/01/2012','DD/MM/YYYY') AND to_date('31/12/2012','DD/MM/YYYY')
  2  /
Explained
SQL>      SELECT * FROM  TABLE( DBMS_XPLAN.display);
PLAN_TABLE_OUTPUT
Plan hash value: 4189439861
| Id  | Operation         | Name      | Rows  | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT  |           |   954 |   139K|     7   (0)| 00:00:01 |
|*  1 |  TABLE ACCESS FULL| DATE_TEST |   954 |   139K|     7   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   1 - filter("START_DATE">=TO_DATE(' 2012-01-01 00:00:00',
              'syyyy-mm-dd hh24:mi:ss') AND "START_DATE"<=TO_DATE(' 2012-12-31
              00:00:00', 'syyyy-mm-dd hh24:mi:ss') OR "END_DATE">=TO_DATE('
              2012-01-01 00:00:00', 'syyyy-mm-dd hh24:mi:ss') AND
              "END_DATE"<=TO_DATE(' 2012-12-31 00:00:00', 'syyyy-mm-dd hh24:mi:s
Note
PLAN_TABLE_OUTPUT
   - dynamic sampling used for this statement (level=2)
21 rows selectedWhy it is not taking index and what are the other solutions for this

Answer 1

Full Table Scan is not evil..
Is your table stats up to date?
The number of rows in the table is shown as 954. Index scan wont be much useful..
How many records are expected in the output?
If it is a major percentage of the total records, Index scan will be more costly..
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