Comments on: How to paginate through an ordered result set http://oraqa.com/2006/02/09/how-to-paginate-through-an-ordered-result-set/ Oracle Question and Answer Mon, 19 Dec 2011 14:21:07 -0700 http://wordpress.org/?v=2.8.4 hourly 1 By: Karl Reitschuster http://oraqa.com/2006/02/09/how-to-paginate-through-an-ordered-result-set/comment-page-1/#comment-120 Karl Reitschuster Sat, 11 Feb 2006 18:54:36 +0000 http://oraqa.com/2006/02/09/how-to-paginate-through-an-ordered-result-set/#comment-120 Thank you! is see both variants uses the same resources. and strange - on the second plan only 75% of CPU cost is shown; where is the rest? But that's not a 'winning battle question' Regards Karl Thank you!
is see both variants uses the same resources.
and strange – on the second plan only 75% of CPU cost is shown;
where is the rest? But that’s not a ‘winning battle question’
Regards
Karl

]]> By: Eddie Awad http://oraqa.com/2006/02/09/how-to-paginate-through-an-ordered-result-set/comment-page-1/#comment-119 Eddie Awad Sat, 11 Feb 2006 04:37:35 +0000 http://oraqa.com/2006/02/09/how-to-paginate-through-an-ordered-result-set/#comment-119 Using rownum: <pre> -------------------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | -------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 107 | 3638 | 4 (25)| 00:00:01 | |* 1 | VIEW | | 107 | 3638 | 4 (25)| 00:00:01 | |* 2 | COUNT STOPKEY | | | | | | | 3 | VIEW | | 107 | 2247 | 4 (25)| 00:00:01 | |* 4 | SORT ORDER BY STOPKEY| | 107 | 1605 | 4 (25)| 00:00:01 | | 5 | TABLE ACCESS FULL | EMPLOYEES | 107 | 1605 | 3 (0)| 00:00:01 | -------------------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 1 - filter("R">=TO_NUMBER(:LOWER)) 2 - filter(ROWNUM<=TO_NUMBER(:HIGHER)) 4 - filter(ROWNUM<=TO_NUMBER(:HIGHER)) Statistics ---------------------------------------------------------- 0 recursive calls 0 db block gets 7 consistent gets 0 physical reads 0 redo size 556 bytes sent via SQL*Net to client 380 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 1 sorts (memory) 0 sorts (disk) 3 rows processed </pre> Using row_number: <pre> ---------------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | ---------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 107 | 3638 | 4 (25)| 00:00:01 | |* 1 | VIEW | | 107 | 3638 | 4 (25)| 00:00:01 | | 2 | WINDOW SORT | | 107 | 1605 | 4 (25)| 00:00:01 | |* 3 | FILTER | | | | | | | 4 | TABLE ACCESS FULL| EMPLOYEES | 107 | 1605 | 3 (0)| 00:00:01 | ---------------------------------------------------------------------------------- Predicate Information (identified by operation id): --------------------------------------------------- 1 - filter("RN">=TO_NUMBER(:LOWER) AND "RN"<=TO_NUMBER(:HIGHER)) 3 - filter(TO_NUMBER(:LOWER)<=TO_NUMBER(:HIGHER)) Statistics ---------------------------------------------------------- 0 recursive calls 0 db block gets 7 consistent gets 0 physical reads 0 redo size 556 bytes sent via SQL*Net to client 380 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 1 sorts (memory) 0 sorts (disk) 3 rows processed </pre> Looks like the optimizer had to go through less steps using row_number. Using rownum:

--------------------------------------------------------------------------------------
| Id  | Operation                | Name      | Rows  | Bytes | Cost (%CPU)| Time     |
--------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT         |           |   107 |  3638 |     4  (25)| 00:00:01 |
|*  1 |  VIEW                    |           |   107 |  3638 |     4  (25)| 00:00:01 |
|*  2 |   COUNT STOPKEY          |           |       |       |            |          |
|   3 |    VIEW                  |           |   107 |  2247 |     4  (25)| 00:00:01 |
|*  4 |     SORT ORDER BY STOPKEY|           |   107 |  1605 |     4  (25)| 00:00:01 |
|   5 |      TABLE ACCESS FULL   | EMPLOYEES |   107 |  1605 |     3   (0)| 00:00:01 |
--------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter("R">=TO_NUMBER(:LOWER))
   2 - filter(ROWNUM< =TO_NUMBER(:HIGHER))
   4 - filter(ROWNUM<=TO_NUMBER(:HIGHER))

Statistics
----------------------------------------------------------
          0  recursive calls
          0  db block gets
          7  consistent gets
          0  physical reads
          0  redo size
        556  bytes sent via SQL*Net to client
        380  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
          1  sorts (memory)
          0  sorts (disk)
          3  rows processed

Using row_number:

----------------------------------------------------------------------------------
| Id  | Operation            | Name      | Rows  | Bytes | Cost (%CPU)| Time     |
----------------------------------------------------------------------------------
|   0 | SELECT STATEMENT     |           |   107 |  3638 |     4  (25)| 00:00:01 |
|*  1 |  VIEW                |           |   107 |  3638 |     4  (25)| 00:00:01 |
|   2 |   WINDOW SORT        |           |   107 |  1605 |     4  (25)| 00:00:01 |
|*  3 |    FILTER            |           |       |       |            |          |
|   4 |     TABLE ACCESS FULL| EMPLOYEES |   107 |  1605 |     3   (0)| 00:00:01 |
----------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter("RN">=TO_NUMBER(:LOWER) AND "RN"< =TO_NUMBER(:HIGHER))
   3 - filter(TO_NUMBER(:LOWER)<=TO_NUMBER(:HIGHER))

Statistics
----------------------------------------------------------
          0  recursive calls
          0  db block gets
          7  consistent gets
          0  physical reads
          0  redo size
        556  bytes sent via SQL*Net to client
        380  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
          1  sorts (memory)
          0  sorts (disk)
          3  rows processed

Looks like the optimizer had to go through less steps using row_number. ]]> By: Karl Reitschuster http://oraqa.com/2006/02/09/how-to-paginate-through-an-ordered-result-set/comment-page-1/#comment-117 Karl Reitschuster Fri, 10 Feb 2006 10:49:30 +0000 http://oraqa.com/2006/02/09/how-to-paginate-through-an-ordered-result-set/#comment-117 Hi Eddie, how about the execution plans - are they the same? Greetings Hi Eddie,
how about the execution plans – are they the same?
Greetings

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