International Business Machines Corporation

Roger Luo Quan Zheng

Adam J Storm

Sam Sampson Lightstone

Christian Marcelo Garcia-Arellano

Wojciech Kuczynski

Sarah Posner

Matthew Albert Huras

Mark Francis Wilding

Aamer U Sachedina

Sunil Jeevananda Kamath

James Liam Finnie

Kevin R Rose

Lan Pham

Taavi Andrew Burns

There are disclosed systems and computer program products for dynamically resizing memory pools used by database management systems. In one aspect, if a decrease in allocation to the memory pool is required, at least one page grouping that may be freed from the memory pool is identified as a candidate based on its position in a list of page groupings. If the page grouping contains any used memory blocks, the used memory blocks may be copied from a candidate page grouping to another page grouping in the list in order to free the candidate page grouping. Once the candidate page grouping is free of used memory blocks, the candidate page grouping may be freed from the memory pool. As an example, this system or computer program product may be used for dynamically resizing locklists or lock memory.

Systems for dynamically resizing memory pools

There are disclosed methods for dynamically resizing memory pools used by database management systems. In one aspect, if a decrease in allocation to the memory pool is required, at least one page grouping that may be freed from the memory pool is identified as a candidate based on its position in a list of page groupings. If the page grouping contains any used memory blocks, the used memory blocks may be copied from a candidate page grouping to another page grouping in the list in order to free the candidate page grouping. Once the candidate page grouping is free of used memory blocks, the candidate page grouping may be freed from the memory pool. As an example, this method may be used for dynamically resizing locklists or lock memory.

Methods for dynamically resizing memory pools

A method and system for improving memory access patterns of software systems on NUMA systems discovers NUMA system resources where the NUMA system resources comprises a plurality of NUMA nodes; determines a plurality of database threads, processes, and objects for a database configuration; and generates a policy which assigns the plurality of database threads, processes, and objects to the plurality of NUMA nodes, wherein the generating of the policy is performed prior to initialization of the plurality of database threads, processes, and objects. The assignment of the database threads, processes, or objects to NUMA nodes is such that the amount of remote memory accesses is reduced. When the database thread, process, or object initializes, the database server queries the policy for its assigned NUMA node(s). The database thread, process, or object is then bound to the assigned NUMA node(s).

System and method for optimally configuring software systems for a NUMA platform

A method and apparatus are provided for storing transaction data for a plurality of database applications in a multiple access database management system having permanent storage and a transaction log buffer to store data for said database applications before transferring said data to said permanent storage, wherein database connection agents associated with said applications are used to store data in said transaction log buffer, including granting exclusive write access reservations in said transaction log buffer to a plurality of said database connection agents; and allowing database connection agents to write transaction data records to previously granted write access reservations while granting exclusive access reservations to other database connection agents.

Method and apparatus for chunk based transaction logging with asynchronous input/output for a database management system

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Richmond Hill, Canada

Roger Luo Quan Zheng