Extreme slowdown of update statement

From: Vladimir Barac <vbarac_at_Alghanim.com>
Date: Sun, 28 Dec 2008 22:30:04 +0300
Message-ID: <C85D70C785B07043A485C8AE85E8F671043AAED558@ALGMB.Alghanim.com>

Hi, listers

Oracle EE 10.2.0.4 64bit, Linux

We have some update statement (part of PL/SQL procedure) that may run for less than a minute if executed from SQL*Plus prompt or may take ~30 minutes if executed as a DBMS_SCHEDULER scheduled job. TKPROF output is pasted below.

What could be the reason for this behaviour? Is there some "slowdown" imposed by DBMS_SCHEDULER?

All insights are welcomed,
Vladimir Barac

---

UPDATE /*+ no_parallel(x) */ ELE_PRODUCT X SET X.FIRST_FOB_PRICE =(SELECT   MAX(D.UNIT_PRICE) FROM ELEC_PO_ORDER_DETAILS D,ELEC_PO E,(SELECT   MIN(B.DATE_CREATED) MIN_DATE,MAX(B.DATE_CREATED) MAX_DATE,A.ITEM_NO FROM   ELEC_PO_ORDER_DETAILS A,ELEC_PO B
WHERE
 A.COMP_CODE=B.COMP_CODE AND A.PO_NO=B.PO_NO GROUP BY ITEM_NO) C WHERE   D.COMP_CODE=E.COMP_CODE AND D.PO_NO=E.PO_NO AND E.DATE_CREATED = C.MIN_DATE   AND D.ITEM_NO = X.ITEM_CODE AND C.ITEM_NO = X.ITEM_CODE) call count cpu elapsed disk query current rows ------- ------ -------- ---------- ---------- ---------- ---------- ----------

Parse        1      0.06       0.07          1        432          0           0
Execute      1   1747.92    1732.64        209     753991     120144       54039
Fetch        0      0.00       0.00          0          0          0           0
------- ------  -------- ---------- ---------- ---------- ----------  ----------
total        2   1747.98    1732.72        210     754423     120144       54039

Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 24 (DM_ELEC_MANAGER) (recursive depth: 2) Rows Execution Plan

-------  ---------------------------------------------------
      0  UPDATE STATEMENT   MODE: ALL_ROWS
      0   UPDATE OF 'ELE_PRODUCT'
      0    TABLE ACCESS   MODE: ANALYZED (FULL) OF 'ELE_PRODUCT' (TABLE)
      0    SORT (AGGREGATE)
      0     HASH JOIN
      0      NESTED LOOPS
      0       VIEW
      0        SORT (GROUP BY)
      0         NESTED LOOPS
      0          INDEX   MODE: ANALYZED (RANGE SCAN) OF


                     'ELEC_PO_ORDER_DETAILS1' (INDEX)

      0          INDEX   MODE: ANALYZED (RANGE SCAN) OF


                     'CUST_ELEC_PO01' (INDEX)

      0       INDEX   MODE: ANALYZED (RANGE SCAN) OF 'ELEC_PO2' (INDEX)
      0      INDEX   MODE: ANALYZED (RANGE SCAN) OF
                 'ELEC_PO_ORDER_DETAILS1' (INDEX)

Elapsed times include waiting on following events:
  Event waited on                             Times   Max. Wait  Total Waited
  ----------------------------------------   Waited  ----------  ------------
  db file sequential read                       209        0.10          1.45
  log file switch completion                      4        0.09          0.18
  log buffer space                                5        0.25          0.74
********************************************************************************


********************************************************************************

UPDATE /*+ no_parallel(x) */ ELE_PRODUCT X SET X.FIRST_FOB_PRICE =(SELECT   MAX(D.UNIT_PRICE) FROM ELEC_PO_ORDER_DETAILS D,ELEC_PO E,(SELECT   MIN(B.DATE_CREATED) MIN_DATE,MAX(B.DATE_CREATED) MAX_DATE,A.ITEM_NO FROM   ELEC_PO_ORDER_DETAILS A,ELEC_PO B
WHERE
 A.COMP_CODE=B.COMP_CODE AND A.PO_NO=B.PO_NO GROUP BY ITEM_NO) C WHERE   D.COMP_CODE=E.COMP_CODE AND D.PO_NO=E.PO_NO AND E.DATE_CREATED = C.MIN_DATE   AND D.ITEM_NO = X.ITEM_CODE AND C.ITEM_NO = X.ITEM_CODE) call count cpu elapsed disk query current rows ------- ------ -------- ---------- ---------- ---------- ---------- ----------

Parse        1      0.05       0.22          2        432          0           0
Execute      1     28.68      28.62          0     743780     119906       54039
Fetch        0      0.00       0.00          0          0          0           0
------- ------  -------- ---------- ---------- ---------- ----------  ----------
total        2     28.73      28.84          2     744212     119906       54039

Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 24 (DM_ELEC_MANAGER) (recursive depth: 1) Rows Execution Plan

-------  ---------------------------------------------------
      0  UPDATE STATEMENT   MODE: ALL_ROWS
      0   UPDATE OF 'ELE_PRODUCT'
      0    TABLE ACCESS   MODE: ANALYZED (FULL) OF 'ELE_PRODUCT' (TABLE)
      0    SORT (AGGREGATE)
      0     HASH JOIN
      0      NESTED LOOPS
      0       VIEW
      0        SORT (GROUP BY)
      0         NESTED LOOPS
      0          INDEX   MODE: ANALYZED (RANGE SCAN) OF


                     'ELEC_PO_ORDER_DETAILS1' (INDEX)

      0          INDEX   MODE: ANALYZED (RANGE SCAN) OF


                     'CUST_ELEC_PO01' (INDEX)

      0       INDEX   MODE: ANALYZED (RANGE SCAN) OF 'ELEC_PO2' (INDEX)
      0      INDEX   MODE: ANALYZED (RANGE SCAN) OF
                 'ELEC_PO_ORDER_DETAILS1' (INDEX)
********************************************************************************

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Received on Sun Dec 28 2008 - 13:30:04 CST