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.