Preferentially Retaining Memory Pages Using a Volatile Database Table Attribute

Patent metadata

Field	Value
Publication number	US-2016171023-A1
Application number	US-201414582175-A
Country	US
Kind code	A1
Filing date	Dec 23, 2014
Priority date	Mar 26, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

A respective volatility attribute associated with each of one or more tables of a computerized database is used to determine circumstances under which a page of table data is paged out of memory, by preferentially retaining pages from volatile database tables in memory. Various optional additional uses of a volatility attribute to manage a database are disclosed. Preferably, database parameters are automatically monitored over time and database table volatility state is automatically determined and periodically adjusted.

First claim

What is claimed is:

1 . A computer program product for managing a computerized database, the computer program product comprising a plurality of computer-executable instructions recorded in a non-transitory computer-readable media, wherein said instructions, when executed by at least one computer system, cause the at least one computer system to perform:
storing at least one respective volatility attribute for each of at least one database table of said computerized database, each volatility attribute expressing volatility of at least a portion of a respective database table of said computerized database; determining circumstances under which a page of data temporarily stored in memory of said at least one computer system and containing data of a first database table of said computerized database is paged out of said memory using the at least one volatility attribute corresponding to the first database table.

2 . The computer program product of claim 1 , wherein the instruction further cause the at least one computer system to perform:
monitoring at least one respective parameter of each said database table of said computerized database over at least one time interval and saving monitored parameter data with respect to the respective database table; and determining a respective volatility state of each said database table using the saved monitored parameter data to automatically generate said at least one respective volatility attribute for each said database table.

3 . The computer program product of claim 1 , wherein the instructions further cause the at least one computer system to perform:
computing a respective figure of merit representing volatility of the at least a portion of the respective database table for each of said at least one time interval.

4 . The computer program product of claim 1 , wherein said computerized database supports the SQL database language and said at least volatility attribute comprises an SQL VOLATILE attribute.

5 . The computer program product of claim 1 , wherein said determining circumstances under which a page of data temporarily stored in memory of said at least one computer system and containing data of a first database table of said computerized database is paged out of said memory comprises preferentially retaining a page of data in memory if the at least one volatility attribute corresponding to the first database table indicates that at least a portion of the first database table containing data stored in the first page is volatile.

6 . The computer program product of claim 5 , wherein said preferentially retaining a page of data in memory comprises pinning the page of data to prevent eviction from memory.

7 . The computer program product of claim 5 , wherein the instruction further cause the at least one computer system to perform:
determining a respective memory retention priority for each of a plurality of database tables or portions of a database table, wherein pages of data from each database table of portion of a database table are preferentially retained according to the respective memory retention priority.

8 . The computer program product of claim 1 , wherein said volatility attribute comprises a quantitative value.

9 . A computer system supporting a database, comprising:
a memory; at least one processor executing instructions storable in said memory; a database table of said database storable in said memory; and a database manager embodied as instructions storable in said memory and executable on said at least one processor, said database manager managing said database and providing access to data in said database table; said database manager including a page retention function which causes said computer system to preferentially retain in said memory one or more pages of data using a respective volatility attribute storable in said memory and associated with the page of data, each volatility attribute expressing volatility of at least a portion of a respective database table of said database containing the associated page of data.

10 . The computer system of claim 9 , wherein the database manager further includes a volatility determining function which:
monitors at least one respective parameter of each of at least one database table of said computerized database over at least one time interval and saves monitored parameter data with respect to the respective database table; and determines a respective volatility state of each said database table using the saved monitored parameter data to automatically generate said at least one respective volatility attribute for each said database table.

11 . The computer system of claim 9 , wherein said volatility attribute comprises a quantitative value.

Assignees

• IBM

Inventors

• Konik Rafal P
• Mittelstadt Roger A
• Muras Brian R
• Theuer Mark W

Classifications

• G06F17/30339

  Physics · mapped topic

• G06F17/30309 Primary

  Physics · mapped topic

• G06F16/116 Primary

  Details of conversion of file system types or formats · CPC title

• G06F16/2282 Primary

  Tablespace storage structures; Management thereof · CPC title

• G06F16/24542

  Plan optimisation · CPC title