SQL> SELECT /*+ PARALLEL(t) */ COUNT(*) FROM t; COUNT(*) ----------- 1937420560 Elapsed: 00:00:24.17 --------------------------------------- | Id | Operation --------------------------------------- | 0 | SELECT STATEMENT | 1 | SORT AGGREGATE | 2 | PX COORDINATOR | 3 | PX SEND QC (RANDOM) | 4 | SORT AGGREGATE | 5 | PX BLOCK ITERATOR | 6 | TABLE ACCESS STORAGE FULL --------------------------------------- Statistics ---------------------------------------------------------- 48 recursive calls 0 db block gets 23233525 consistent gets 23105978 physical reads 0 redo size 526 bytes sent via SQL*Net to client 524 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 16 sorts (memory) 0 sorts (disk) 1 rows processed DP = 16 для 16 секций таблицы
Monday, May 25, 2009
читаем данные с дисков очень быстро...
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1 comment:
Экзадата :)
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