"IN" clause making query to run infinite loop

Question

Hello Masters,
I am using Oracle 9i and using one query with "IN" clause. This query takes arnd 5-6 hours of time to get that completed, but when i removed the "IN" clause with "Inner Join" then query starts completing in seconds.
More over looking at the execution plan for the queries i don't see any differences and the costing is also very low.
Query is:
SELECT contact_id FROM scc_case_contact_t WHERE case_id IN (SELECT id FROM temp_data_manager_t WHERE id_info = 'mDependentCaseIds' AND user_id = 1 AND sess_id = '1769F72A8F7A7B1FB98AAAE6676845F6') AND contact_id IN (SELECT id FROM temp_data_manager_t WHERE id_info = 'arrCntIds' AND user_id = 1 AND sess_id = '1769F72A8F7A7B1FB98AAAE6676845F6')
Execution Plan:
| Id | Operation | Name | Rows | Bytes | Cost |
| 0 | SELECT STATEMENT | | 1 | 272 | 5 |
| 1 | NESTED LOOPS SEMI | | 1 | 272 | 5 |
| 2 | NESTED LOOPS SEMI | | 1 | 142 | 5 |
| 3 | INDEX FAST FULL SCAN | CASE_CONTACT_PK | 94729 | 1110K| 5 |
| 4 | TABLE ACCESS BY INDEX ROWID| TEMP_DATA_MANAGER_T | 1 | 130 | |
| 5 | INDEX RANGE SCAN | TEMP_DATA_MANAGER_IX_ID_INFO | 1 | | |
| 6 | TABLE ACCESS BY INDEX ROWID | TEMP_DATA_MANAGER_T | 1 | 130 | |
| 7 | INDEX RANGE SCAN | TEMP_DATA_MANAGER_IX_ID_INFO | 1 | | |
Almost all the queries with "IN" clause are taking astonishingly high time.
The same set of queries are working fine at Oracle 10G.
Any help on this will be highly appreciated.

Answer 1

This is the modified query
SELECT contact_id FROM scc_case_contact_t inner join
(SELECT id FROM temp_data_manager_t WHERE id_info = 'mDependentCaseIds' AND user_id = 1 AND sess_id LIKE '1769F72A8F7A7B1FB98AAAE6676845F6')X
on X.id=case_id
inner join
(SELECT id FROM temp_data_manager_t WHERE id_info = 'arrCntIds' AND user_id = 1 AND sess_id LIKE '1769F72A8F7A7B1FB98AAAE6676845F6')Y
on Y.ID=contact_id
Execution plan is:
| Id | Operation | Name | Rows | Bytes | Cost |
| 0 | SELECT STATEMENT | | 1 | 272 | 1 |
| 1 | NESTED LOOPS | | 1 | 272 | 1 |
| 2 | MERGE JOIN CARTESIAN | | 1 | 260 | 1 |
| 3 | TABLE ACCESS BY INDEX ROWID | TEMP_DATA_MANAGER_T | 1 | 130 | 1 |
| 4 | INDEX RANGE SCAN | TEMP_DATA_MANAGER_IX_ID_INFO | 1 | | 1 |
| 5 | BUFFER SORT | | 1 | 130 | |
| 6 | TABLE ACCESS BY INDEX ROWID| TEMP_DATA_MANAGER_T | 1 | 130 | |
| 7 | INDEX RANGE SCAN | TEMP_DATA_MANAGER_IX_ID_INFO | 1 | | |
| 8 | INDEX UNIQUE SCAN | CASE_CONTACT_PK | 1 | 12 | |
I had tried using Exists but that also not working and taking arnd 4 -5 hrs.
Also the query with Join condition is completing in 4-5 seconds.