Index not using in select query

Question

Hello All,
I have table CITY with 2 composite primary key CITYCODE, COUNTRYCODE of course they are NOT NULL.
i created an index.
CREATE UNIQUE INDEX CITYKEY ON CITY     (CITYCODE, COUNTRYCODE);
then i run explain plan as follows
explain plan for
select CityCode, CityName, CountryCode, LexiconId, UserId, Status
from City
where CountryCode = 'IR';
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 803 | 57013 | 112 (2)| 00:00:02 |
|* 1 | TABLE ACCESS FULL| CITY | 803 | 57013 | 112 (2)| 00:00:02 |
later i analyze table rebuild indexes but again explain plan gives me the same result.
Could any 1 please guide me to solve this issue.
Thanks
Edited by: mohsin javed on Feb 17, 2011 10:10 AM

Answer 1

Hello All,
Again with one more query which having join:
table SDNMASTER with sdnid pk and SDNMASTER_PK index on SDNID, table SDNALIAS sdnid pk and SDNALIAS_PK index on SDNID.
explain plan for
SELECT a.SourceId,
          a.SourceName,
          b.LastName,
          a.Status
FROM SdnMaster a,
          SdnAlias b
WHERE a.SdnId = b.SdnId
AND a.Status in ('1', '3')
AND b.LastName is not null
ORDER BY b.LastName;
PLAN_TABLE_OUTPUT
Plan hash value: 1153036645
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 2399 | 64773 | 69 (5)| 00:00:01 |
| 1 | SORT ORDER BY | | 2399 | 64773 | 69 (5)| 00:00:01 |
|* 2 | HASH JOIN | | 2399 | 64773 | 68 (3)| 00:00:01 |
|* 3 | TABLE ACCESS FULL| SDNALIAS | 2399 | 21591 | 11 (0)| 00:00:01 |
|* 4 | TABLE ACCESS FULL| SDNMASTER | 4562 | 82116 | 56 (2)| 00:00:01 |
Even after analyzing table and rebuilding index its not using the index..
Thanks