Re: Indexes on temp tables

From: Andrew Kerber <andrew.kerber_at_gmail.com>
Date: Tue, 15 Jan 2008 12:30:36 -0600
Message-ID: <ad3aa4c90801151030k138f6014qc0a6d79157b369d3@mail.gmail.com>


You might try gathering statistics on the table when it is at its largest size and see if it will use the index without a hint then. If it does, lock the statistics so they do not get changed.

If the query uses bind variables, you might be able to create a sql profile with the appropriate plan.

On Jan 15, 2008 12:07 PM, Ram Raman <veeeraman_at_gmail.com> wrote:

> Hi,
>
> Oracle: 10.2.
>
> We have a query that has been running slow. After researching on the query
> I found out that that it was not using an index on one of the temporary
> tables involved. I used a hint to force the query to use the index, and the
> query's perfomance improved very well. But now I learn from the developers
> that the query may use any of a range of temp tables when it runs - there
> seem to be about 24 of them. I have the option of adding hints with the
> names of all indexes for all the temp tables. I tested the query in this way
> and it works fine. This solution works, but is there a better way.
>
> PS. Even though they are called temporary tables, they are in permanent
> tablespace.
>
>
> Qry:
>
> SELECT /*+ INDEX(D PS_CM_ITEM_MTH_T7) INDEX(D PS_CM_ITEM_MTH_T4) INDEX(D
> PS_CM_ITEM_MTH_T7) */
> X.PROCESS_INSTANCE
> , A.BUSINESS_UNIT
> , A.INV_ITEM_ID, A.CM_BOOK, A.DT_TIMESTAMP, A.SEQ_NBR, A.CM_DT_TIMESTAMP,
> A.CM_SEQ_NBR, B.CM_SEQ_COST
> , B.COST_ELEMENT, 0, 0 , 0 , B.CM_UNIT_COST_VO , 0 , 0
> FROM PS_CM_DEPLETE A, PS_CM_RMATCH_S_VW B, PS_TRANSACTION_INV C,
> PS_CM_ITEM_MTH_T4 D, PS_CM_CSTACCTG X
> WHERE X.PROCESS_INSTANCE = 2981824
> AND X.REQUEST_ID = 'AB301'
> AND X.BUSINESS_UNIT = A.BUSINESS_UNIT
> AND X.CM_BOOK = A.CM_BOOK
> AND B.BUSINESS_UNIT_RECV = C.BUSINESS_UNIT_PO
> AND B.RTV_ID = C.RTV_ID
> AND B.RTV_LN_NBR = C.RTV_LN_NBR
> AND B.RTV_DISTRIB_NUM = C.RTV_DISTRIB_NUM
> AND C.BUSINESS_UNIT = A.BUSINESS_UNIT
> AND C.INV_ITEM_ID = A.INV_ITEM_ID
> AND C.DT_TIMESTAMP = A.DT_TIMESTAMP
> AND C.SEQ_NBR = A.SEQ_NBR
> AND A.POSTED_FLAG = 'N'
> AND A.CM_DUMMY_FLG ='N'
> AND D.PROCESS_INSTANCE = X.PROCESS_INSTANCE
> AND D.BUSINESS_UNIT = A.BUSINESS_UNIT
> AND D.INV_ITEM_ID = A.INV_ITEM_ID
> AND D.CM_BOOK = A.CM_BOOK
> AND (D.CM_METHOD NOT IN ('6','9') OR D.CM_COST_ELEMNT_OPT <> '1')
> AND EXISTS (
> SELECT 'X'
> FROM PS_SET_CNTRL_REC
> , PS_CM_ELEMENT
> WHERE A.BUSINESS_UNIT = PS_SET_CNTRL_REC.SETCNTRLVALUE
> AND PS_SET_CNTRL_REC.RECNAME = 'CM_ELEMENT'
> AND PS_CM_ELEMENT.SETID = PS_SET_CNTRL_REC.SETID
> AND PS_CM_ELEMENT.COST_ELEMENT = B.COST_ELEMENT
> AND PS_CM_ELEMENT.COST_CATEGORY = 'MAT' )
> Plan:
>
>
> 17:14:47 SQL> select * from table(dbms_xplan.display);
> more..
>
> PLAN_TABLE_OUTPUT
>
> ------------------------------------------------------------------------------------------------------------------------
>
>
> --------------------------------------------------------------------------------------------------------
> | Id | Operation | Name | Rows |
> Bytes | Cost (%CPU)| Time |
> --------------------------------------------------------------------------------------------------------
>
> | 0 | SELECT STATEMENT | |
> | | 21 (100)| |
> | 1 | HASH GROUP BY | | 1 |
> 259 | 21 (20)| 00:00:01 |
> | 2 | NESTED LOOPS | | 1 |
> 259 | 18 (17)| 00:00:01 |
> | 3 | NESTED LOOPS | | 1 |
> 206 | 17 (18)| 00:00:01 |
> | 4 | MERGE JOIN CARTESIAN | | 1 |
> 139 | 14 (22)| 00:00:01 |
> | 5 | MERGE JOIN CARTESIAN | | 1
> | 78 | 11 (28)| 00:00:01 |
> |* 6 | TABLE ACCESS FULL | PS_CM_ITEM_MTH_T4 | 1
> | 38 | 10 (30)| 00:00:01 |
> | 7 | BUFFER SORT | | 1
> | 40 | 1 (0)| 00:00:01 |
> |* 8 | INDEX RANGE SCAN | PSBCM_CSTACCTG | 1
> | 40 | 1 (0)| 00:00:01 |
> | 9 | BUFFER SORT | | 93 |
> 5673 | 13 (24)| 00:00:01 |
> |* 10 | TABLE ACCESS FULL | PS_CM_RMATCH_COST | 93 |
> 5673 | 3 (0)| 00:00:01 |
> |* 11 | TABLE ACCESS BY INDEX ROWID | PS_CM_DEPLETE | 1
> | 67 | 3 (0)| 00:00:01 |
> |* 12 | INDEX RANGE SCAN | PSACM_DEPLETE | 18
> | | 2 (0)| 00:00:01 |
> | 13 | NESTED LOOPS | | 1
> | 40 | 2 (0)| 00:00:01 |
> |* 14 | TABLE ACCESS BY INDEX ROWID| PS_CM_ELEMENT | 1
> | 13 | 1 (0)| 00:00:01 |
> |* 15 | INDEX SKIP SCAN | PS_CM_ELEMENT | 1
> | | 1 (0)| 00:00:01 |
> |* 16 | INDEX UNIQUE SCAN | PSASET_CNTRL_REC | 1
> | 27 | 1 (0)| 00:00:01 |
> |* 17 | TABLE ACCESS BY INDEX ROWID | PS_TRANSACTION_INV | 1
> | 53 | 1 (0)| 00:00:01 |
> |* 18 | INDEX UNIQUE SCAN | PS_TRANSACTION_INV | 1
> | | 1 (0)| 00:00:01 |
>
> --------------------------------------------------------------------------------------------------------
> Thanks.
>
>
>

-- 
Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'

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Received on Tue Jan 15 2008 - 12:30:36 CST

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