AWR sql report

Question

Hi,
on 11g R2, I ran awrsqrpt.sql and received the following :
-> % Total DB Time is the Elapsed Time of the SQL statement divided
   into the Total Database Time multiplied by 100
Stat Name                                Statement   Per Execution % Snap
Elapsed Time (ms)                         2,483,336    2,483,335.9     1.2
CPU Time (ms)                               138,340      138,340.0     0.2
Executions                                        1            N/A     N/A
Buffer Gets                               2,176,636    2,176,636.0     0.1
Disk Reads                                  805,870      805,870.0     0.6
Parse Calls                                       1            1.0     0.0
Rows                                        137,462      137,462.0     N/A
User I/O Wait Time (ms)                   2,265,412            N/A     N/A
Cluster Wait Time (ms)                      123,124            N/A     N/A
Application Wait Time (ms)                        0            N/A     N/A
Concurrency Wait Time (ms)                        0            N/A     N/A
Invalidations                                     0            N/A     N/A
Version Count                                     3            N/A     N/A
Sharable Mem(KB)                                239            N/A     N/A
Execution Plan
| Id  | Operation                       | Name               | Rows  | Bytes | Cost (%CPU)| Time     |
|   0 | INSERT STATEMENT                |                    |       |       |   441K(100)|          |
|   1 |  LOAD TABLE CONVENTIONAL        |                    |       |       |            |          |
|   2 |   NESTED LOOPS                  |                    |       |       |            |          |
|   3 |    NESTED LOOPS                 |                    |     1 |   172 |   441K  (1)| 01:28:19 |
|   4 |     NESTED LOOPS                |                    |     1 |   135 |   441K  (1)| 01:28:19 |
|   5 |      TABLE ACCESS BY INDEX ROWID| PS_KK_ACTIVITY_LOG |     1 |   105 |   441K  (1)| 01:28:19 |
|   6 |       INDEX RANGE SCAN          | PSEKK_ACTIVITY_LOG |  1982K|       |  9418   (1)| 00:01:54 |
|   7 |      TABLE ACCESS BY INDEX ROWID| PS_KK_SOURCE_HDR   |     1 |    30 |     2   (0)| 00:00:01 |
|   8 |       INDEX UNIQUE SCAN         | PS_KK_SOURCE_HDR   |     1 |       |     1   (0)| 00:00:01 |
|   9 |     INDEX UNIQUE SCAN           | PS_PO_HDR          |     1 |       |     1   (0)| 00:00:01 |
|  10 |    TABLE ACCESS BY INDEX ROWID  | PS_PO_HDR          |     1 |    37 |     2   (0)| 00:00:01 |One can see Elapsed time(ms)=2,483,336
Is it 2483336 in millisecond that means 41 minutes ?
If 41 minutes it's a long qurey . Can we do something to optimize that ?
Thank you.

Answer 1

Hi,
1) the amount of time it takes is not enough grounds for optimization. Only SQL that hurts the business by its slowness needs to be optimized (e.g.: if you tune a nightly batch job to run from 4 hours to 4 minutes no one will probably notice it)
2) if there is a valid business case for optimizing this statement, the first step would be posting the query's text + plan with rowsource stats
Best regards,
Nikolay