公开(公告)号：CA2876466A1

公开(公告)日：2016-06-29

申请号：CA2876466

申请日：2014-12-29

Applicant: IBM CANADA LTD - IBM CANADA LIMITEE

Inventor： FINLAY IAN R ,  KELLER JEFFREY M ,  STORM ADAM J ,  ZUZARTE CALISTO P

IPC: G06F17/30 ,  G06F7/00

Abstract: An illustrative embodiment for optimizing scans using a Bloom filter synopsis, defines metadata to encode distinct values in a range of values associated with a particular portion of a managed object in a database management system into a probabilistic data structure of a Bloom filter that stores an indicator, encoded in a fixed size bit map with one or more bits, indicating whether an element of the particular portion of the managed object is a member of a set of values summarized in the Bloom filter using a value of / or definitely not in the set using a value of 0. The Bloom filter is compressed to create a compressed Bloom filter. The Bloom filter is added to the metadata associated with the managed object and used when testing for values associated with predicates.

公开(公告)号：CA2876379A1

公开(公告)日：2016-06-29

申请号：CA2876379

申请日：2014-12-29

Applicant: IBM CANADA LTD - IBM CANADA LIMITEE

Inventor： STORM ADAM J ,  GARCIA-ARELLANO CHRISTIAN M

IPC: G06F12/00

Abstract: An illustrative embodiment tunes memory in presence of asymmetrical memory transfer costs by assigning a threshold value asynchronously to a memory consumer and a bias value to the threshold. Responsive to an ability to free memory by the consumer and to reclaim memory, direct the memory consumer to reclaim memory. Responsive to a time out or the reclaim exceeds a predetermined amount of time for the memory consumer, multiply the biased threshold value by a predetermined adjustment factor. Responsive to freeing memory under the predetermined time, divide the biased benefit threshold value by the predetermined adjustment factor. Update per memory consumer control values and logically partition the memory according to an ability of the memory consumer to free the memory in a defined ratio. The memory consumer reclaims memory from the second portion and replenishes the second portion asynchronously from the first portion, maintaining the defined ratio.

公开(公告)号：CA2876466C

公开(公告)日：2022-07-05

申请号：CA2876466

申请日：2014-12-29

Applicant: IBM CANADA LTD IBM CANADA LIMITEE

Inventor： FINLAY IAN R ,  KELLER JEFFREY M ,  STORM ADAM J ,  ZUZARTE CALISTO P

IPC: G06F16/14 ,  G06F7/00 ,  G06F16/9035

Abstract: An illustrative embodiment for optimizing scans using a Bloom filter synopsis, defines metadata to encode distinct values in a range of values associated with a particular portion of a managed object in a database management system into a probabilistic data structure of a Bloom filter that stores an indicator, encoded in a fixed size bit map with one or more bits, indicating whether an element of the particular portion of the managed object is a member of a set of values summarized in the Bloom filter using a value of / or definitely not in the set using a value of 0. The Bloom filter is compressed to create a compressed Bloom filter. The Bloom filter is added to the metadata associated with the managed object and used when testing for values associated with predicates.

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.

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.