SQL QUERY TUNING(PARTITONS AND JOIN)

Question

Hello
My below query is taking very long time to execute ..here is the query and explain plan
EXPLAIN PLAN FOR select w.ref_no,a.*
from table1 a left outer join table2 w
on(a.emp_id=w.emp_id)
where a.joining_date=20090205 ;
PLAN_TABLE_OUTPUT
| Id | Operation | Name | Rows | Bytes |TempSpc| Cost (%CPU)| Pstart| Pstop |
| 0 | SELECT STATEMENT | | 2415K| 504M| | 226K (2)| | |
|* 1 | HASH JOIN OUTER | | 2415K| 504M| 488M| 226K (2)| | |
|* 2 | TABLE ACCESS BY INDEX ROWID| table1 | 2415K| 460M| | 77975 (1)| | |
|* 3 | INDEX RANGE SCAN | table1_joining_ DATE | 2441K| | | 6463 (2)| | |
| 4 | PARTITION RANGE ALL | | 39M | 718M| | 64745 (2)| 1 | 4 |
| 5 | TABLE ACCESS FULL | table2 | 39M | 718M| | 64745 (2)| 1 | 4 |
table 2 has 40 million rows
Table2 structure
emp_id
ref_no
Project_id
Partitoned on Project_id, Project_id is nowhere used on the above query
Table1 Structure
emp_id
joining_date
other columns
Is indexed on joining_date, not partitioned
Please advise

Answer 1

The CBO has estimated that you have 2415K table1 rows where joining_date = 20090205. (By the way: is this really a number?!)
Is this estimate accurate?
Please add some more information:
- Which version do you use
- How long is "very long time"?
- How many does your query return
- information as described in this thread: When your query takes too long ...
Regards,
Rob.