Reg update of a 10 million record table from 1 million record table

Question

I have 2 tables
Tabke 1 : 10 millio records
21 indexes --> 1). acct_id , acct_seq_no -- index_1
2). c1 , c2 , c3 -- index_2
Table 2 : 1 .5 million records
1 index on ( acct_id, acct_seq_no) - idx_1
common keys are acct_id and acct_seq_no
I'm updating table1 from table 2
I need to use index ( index_1 from table_1 ) and (idx_1 from table_2)
How can I make my query to use only this particular index.
MY query ia as follows
UPDATE csban_&1 csb
SET (
duns_no,
hdqtrs_duns_no,
us_ultmt_duns_no,
sci_id,
blg_cl_id,
cl_id
) =
( SELECT acct_id,
acct_seq_no,
duns_no,
hdqtrs_duns_no,
us_ultmt_duns_no,
sci_id,
blg_cl_id,
cl_id
FROM csban_abi_temp
WHERE csb.acct_id = temp.acct_id
AND csb.acct_seq_no = temp.acct_seq_no
AND rownum < 2
WHERE
EXISTS
SELECT 1
FROM csban_abi_temp temp1
WHERE csb.acct_id = temp1.acct_id
AND csb.acct_seq_no = temp1.acct_seq_no
DO I need to put and index hint after this
UPDATE csban_&1 csb --???????? /*+ indedx (csb.index_1) */
Thanks in advance

Answer 1

Thanks a lot david and rob for sharing the info.
Please find the details
SQL> EXPLAIN PLAN FOR
UPDATE csban_2 csb
SET (
duns_no,
hdqtrs_duns_no,
us_ultmt_duns_no,
sci_id,
blg_cl_id,
cl_id
) =
( SELECT duns_no,
hdqtrs_duns_no,
us_ultmt_duns_no,
sci_id,
blg_cl_id,
cl_id
FROM csban_abi_temp temp
WHERE csb.acct_id = temp.acct_id
AND csb.acct_seq_no = temp.acct_seq_no
AND rownum < 2
WHERE
EXISTS
SELECT 1
FROM csban_abi_temp temp1
WHERE 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29
Explained.
SQL>
SQL>
SQL> SELECT * FROM TABLE(dbms_xplan.display);
PLAN_TABLE_OUTPUT
Plan hash value: 584770029
| Id | Operation | Name | Rows | Bytes | Cost
| TQ |IN-OUT| PQ Distrib |
PLAN_TABLE_OUTPUT
| 0 | UPDATE STATEMENT | | 530K| 19M| 8213
| | | |
| 1 | UPDATE | CSBAN_2 | | |
| | | |
|* 2 | FILTER | | | |
| | | |
| 3 | PX COORDINATOR | | | |
| | | |
PLAN_TABLE_OUTPUT
| 4 | PX SEND QC (RANDOM) | :TQ10000 | 530K| 19M| 8213
| Q1,00 | P->S | QC (RAND) |
| 5 | PX BLOCK ITERATOR | | 530K| 19M| 8213
| Q1,00 | PCWC | |
| 6 | TABLE ACCESS FULL | CSBAN_2 | 530K| 19M| 8213
| Q1,00 | PCWP | |
|* 7 | INDEX RANGE SCAN | IDX_CSB_ABI_TMP | 1 | 10 | 3
PLAN_TABLE_OUTPUT
| | | |
|* 8 | COUNT STOPKEY | | | |
| | | |
| 9 | TABLE ACCESS BY INDEX ROWID| CSBAN_ABI_TEMP | 1 | 38 | 4
| | | |
|* 10 | INDEX RANGE SCAN | IDX_CSB_ABI_TMP | 1 | | 3
| | | |
PLAN_TABLE_OUTPUT
Predicate Information (identified by operation id):
2 - filter( EXISTS (SELECT 0 FROM "CSBAN_ABI_TEMP" "TEMP1" WHERE "TEMP1"."ACC
T_SEQ_NO"=:B1 AND
"TEMP1"."ACCT_ID"=:B2))
PLAN_TABLE_OUTPUT
7 - access("TEMP1"."ACCT_ID"=:B1 AND "TEMP1"."ACCT_SEQ_NO"=:B2)
8 - filter(ROWNUM<2)
10 - access("TEMP"."ACCT_ID"=:B1 AND "TEMP"."ACCT_SEQ_NO"=:B2)
Note
- cpu costing is off (consider enabling it)
30 rows selected.
The query had completed and it took 1 hr 47 mts.
SQL> SQL> SQL> Updating CSBAN from TEMP table
old 1: UPDATE /*+ INDEX(acct_id,acct_seq_no) */ csban_&1 csb
new 1: UPDATE /*+ INDEX(acct_id,acct_seq_no) */ csban_1 csb
1611807 rows updated.
Elapsed: 01:47:16.40