TKPROF - help

Hi,

Can somebody tell me how to read the "Execution plan" produced by the TKPROF utility (Oracle V6).

I can remember reading somewhere that you read from the furthest indented to the right and bottom up.

In the examples below I have listed 3 extra columns which show the ways in which the query could be executed and where the differences occur. Would someone please indicate which is correct, why and where I can read about this.   

EG

SORT (ORDER BY)                                                   6    6
  SORT (GROUP BY)                                                 5    5
    NESTED LOOPS                                                  4    4
      TABLE ACCESS (FULL) OF 'Provider'                           3    1   *
      TABLE ACCESS (BY ROWID) OF 'PP_Service'                     2    3   *
        INDEX (RANGE SCAN) OF 'I_PP_Service_2' (NON-UNIQUE)       1    2   *

Here's one that's a lot more complex.

SORT(UNIQUE)                                                    16    16
  FILTER                                                        15    15
    NESTED LOOPS                                                10    10
      NESTED LOOPS                                               7     7
        NESTED LOOPS                                             4     4
          TABLE ACCESS (FULL) OF 'CLIENT'                        3     1   *
          TABLE ACCESS (BY ROWID) OF 'PP_SERVICE'                2     3   *
            INDEX (RANGE SCAN) OF 'I_PP_SERVICE_1' (UNIQUE)      1     2   *
        TABLE ACCESS (BY ROWID) OF 'PROVIDER'                    6     6
          INDEX (UNIQUE SCAN) OF 'I_PROVIDER_1' (UNIQUE)         5     5
      TABLE ACCESS (BY ROWID) OF 'PP_SERVICE'                    9     9
        INDEX (RANGE SCAN) OF 'I_PP_SERVICE_1' (UNIQUE)          8     8
    TABLE ACCESS (BY ROWID) OF 'PP_SERVICE'                     14    12   *
      INDEX (RANGE SCAN) OF 'I_PP_SERVICE_1' (UNIQUE)           13    11   *
    TABLE ACCESS (BY ROWID) OF 'PP_SERVICE'                     12    14   *
      INDEX (RANGE SCAN) OF 'I_PP_SERVICE_1' (UNIQUE)           11    13   *
    

Any help appreciated.

Thanks.

-- 
Bruce...        pihlab_at_cbr.hhcs.gov.au

"If you swallow a live frog first thing in the morning ...
 Nothing worse will happen to either of you for the rest of the day."

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* Bruce Pihlamae  --  Database Administration                     *

* Commonwealth Department of                                      * 

*          Health, Housing, Local Government & Community Services *


* Canberra, Australia                             (W) 06-289-7056 *


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* These are my own thoughts and opinions, few that I have.        *


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