公开(公告)号：CA2427216A1

公开(公告)日：2004-10-30

申请号：CA2427216

申请日：2003-04-30

Applicant: IBM CANADA

Inventor： HORNIBROOK JOHN F ,  STORM ADAM J ,  ZILIO DANIELE C ,  FINLAY IAN R ,  FLASZA MIROSLAW A

IPC: G06F7/24 ,  G06F17/30 ,  G06F9/44

Abstract: The invention improves performance of a query in a database system when a pl an for the query includes sorting an input that is at least partially sorted such that a slow materialization sort can be applied. The invention applies the slow materialization sort by determini ng a sequence of subsets in accordance with the partially sorted input. As each of the subset s is determined, the subset is output for further processing. Advantageously, the invention reduc es the waiting period for obtaining results from a sorting operation under certain circumstances.

公开(公告)号：CA2408481A1

公开(公告)日：2004-04-17

申请号：CA2408481

申请日：2002-10-17

Applicant: IBM CANADA

Inventor： STORM ADAM J ,  ZILIO DANIELE C ,  LIGHTSTONE SAM S ,  VALENTIN GARY

IPC: G06F9/50 ,  G06F12/02 ,  G06F12/0866

Abstract: Buffer pools permit quick access to data. A simulated buffer pool extensi on (SBPX) is created for each buffer pool in a set of buffer pools. Data victimized from a buffer pool is represented in the associated SBPX. Requests for data that is not resident in a buffer pool but is represented in the associated SBPX are tallied. Periodically, an expected efficiency benefit of increasing the capacity of each buffer pool i s determined from the tallies. Memory is reallocated from the buffer pool with the lowest expected efficiency benefit having remaining reallocatable memory to the buffer pool with the highest expected efficiency benefit having remaining reallocatable memory, until either one or both of the buffer pools exhausts its reallocatable memory. This is repeated until all reallocatable memory has been reallocated, until only one buffer pool wi th reallocatable memory remains, or until all buffer pools with remaining reallocatable memor y have substantially the same expected efficiency benefit.

公开(公告)号：CA2408481C

公开(公告)日：2009-10-06

申请号：CA2408481

申请日：2002-10-17

Applicant: IBM CANADA

Inventor： STORM ADAM J ,  VALENTIN GARY ,  ZILIO DANIELE C ,  LIGHTSTONE SAM S

IPC: G06F12/02 ,  G06F9/50 ,  G06F12/0866

Abstract: Buffer pools permit quick access to data. A simulated buffer pool extensi on (SBPX) is created for each buffer pool in a set of buffer pools. Data victimized from a buffer pool is represented in the associated SBPX. Requests for data that is not resident in a buffer pool but is represented in the associated SBPX are tallied. Periodically, an expected efficiency benefit of increasing the capacity of each buffer pool i s determined from the tallies. Memory is reallocated from the buffer pool with the lowest expected efficiency benefit having remaining reallocatable memory to the buffer pool with the highest expected efficiency benefit having remaining reallocatable memory, until either one or both of the buffer pools exhausts its reallocatable memory. This is repeated until all reallocatable memory has been reallocated, until only one buffer pool wi th reallocatable memory remains, or until all buffer pools with remaining reallocatable memor y have substantially the same expected efficiency benefit.