スター型変換を含む動的プルーニング

データベースによってスター型変換を使用して変換される文では、動的なプルーニングが行われます。次に例を示します。
SQL> explain plan for select p.prod_name, t.time_id, sum(s.amount_sold)
     from sales s, times t, products p
     where s.time_id = t.time_id and s.prod_id = p.prod_id and t.fiscal_year = 2000
     and t.fiscal_week_number = 3 and p.prod_category = 'Hardware'
     group by t.time_id, p.prod_name;
Explained.

SQL> select * from table(dbms_xplan.display);
PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------
Plan hash value: 4020965003

------------------------------------------------------------------------------------------------------
| Id  | Operation                             | Name                 | Rows  | Bytes | Pstart| Pstop |
------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT                      |                      |     1 |    79 |       |       |
|   1 |  HASH GROUP BY                        |                      |     1 |    79 |       |       |
|*  2 |   HASH JOIN                           |                      |     1 |    79 |       |       |
|*  3 |    HASH JOIN                          |                      |     2 |    64 |       |       |
|*  4 |     TABLE ACCESS FULL                 | TIMES                |     6 |    90 |       |       |
|   5 |     PARTITION RANGE SUBQUERY          |                      |   587 |  9979 |KEY(SQ)|KEY(SQ)|
|   6 |      TABLE ACCESS BY LOCAL INDEX ROWID| SALES                |   587 |  9979 |KEY(SQ)|KEY(SQ)|
|   7 |       BITMAP CONVERSION TO ROWIDS     |                      |       |       |       |       |
|   8 |        BITMAP AND                     |                      |       |       |       |       |
|   9 |         BITMAP MERGE                  |                      |       |       |       |       |
|  10 |          BITMAP KEY ITERATION         |                      |       |       |       |       |
|  11 |           BUFFER SORT                 |                      |       |       |       |       |
|* 12 |            TABLE ACCESS FULL          | TIMES                |     6 |    90 |       |       |
|* 13 |           BITMAP INDEX RANGE SCAN     | SALES_TIME_BIX       |       |       |KEY(SQ)|KEY(SQ)|
|  14 |         BITMAP MERGE                  |                      |       |       |       |       |
|  15 |          BITMAP KEY ITERATION         |                      |       |       |       |       |
|  16 |           BUFFER SORT                 |                      |       |       |       |       |
|  17 |            TABLE ACCESS BY INDEX ROWID| PRODUCTS             |    14 |   658 |       |       |
|* 18 |             INDEX RANGE SCAN          | PRODUCTS_PROD_CAT_IX |    14 |       |       |       |
|* 19 |           BITMAP INDEX RANGE SCAN     | SALES_PROD_BIX       |       |       |KEY(SQ)|KEY(SQ)|
|  20 |    TABLE ACCESS BY INDEX ROWID        | PRODUCTS             |    14 |   658 |       |       |
|* 21 |     INDEX RANGE SCAN                  | PRODUCTS_PROD_CAT_IX |    14 |       |       |       |
------------------------------------------------------------------------------------------------------

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

   2 - access("S"."PROD_ID"="P"."PROD_ID")
   3 - access("S"."TIME_ID"="T"."TIME_ID")
   4 - filter("T"."FISCAL_WEEK_NUMBER"=3 AND "T"."FISCAL_YEAR"=2000)
  12 - filter("T"."FISCAL_WEEK_NUMBER"=3 AND "T"."FISCAL_YEAR"=2000)
  13 - access("S"."TIME_ID"="T"."TIME_ID")
  18 - access("P"."PROD_CATEGORY"='Hardware')
  19 - access("S"."PROD_ID"="P"."PROD_ID")
  21 - access("P"."PROD_CATEGORY"='Hardware')

Note
-----
   - star transformation used for this statement
注意:
Cost (%CPU)列とTime列は、この例の計画表の出力では削除されています。