Allocating free space in a database

Patent metadata

Field	Value
Publication number	US-10078647-B2
Application number	US-201715664866-A
Country	US
Kind code	B2
Filing date	Jul 31, 2017
Priority date	Mar 23, 2016
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

Allocating free space in a database table. Statistics associated with records in a database are received, including an average record byte size for records stored in the database table. A primary free space byte size for record updates is determined, including comparing a preliminary free space byte size to the average record byte size and a byte size of a record subjected to a database operation. Based on the primary free space byte size, free space at the page level of the database table is allocated.

First claim

What is claimed is:

1. A computer-implemented method for allocating free space in a database table associated with a relation database managed by a relational database management system, the method comprising:
receiving statistics associated with records in a database table, including an average record byte size for records stored in the database table;
receiving a database operation, wherein the received database operation comprises an insertion operation, a deletion operation, and an update operation;
determining a primary free space byte size for record updates based on the received database operation, wherein determining the primary free space byte size for record updates comprises comparing a preliminary free space byte size to the average record byte size and a byte size of a subject record, wherein determining the primary free space byte size further comprises modifying the preliminary free space byte size based on the average record byte size and the byte size of the subject record, wherein the subject record is subjected to the received database operation, wherein determining the primary free space byte size is in response to commencing a database utility, and wherein the database utility is associated with at least one of a reorganization process and a page loading process;
in response to determining that the received database operation is an insertion operation, increasing the preliminary free space byte size based on a first difference in byte size between the average record byte size and the byte size of the subject record, and wherein the byte size of the subject record is less than the average record byte size;
in response to determining that the received database operation is a deletion operation, decreasing the preliminary free space byte size based on a second difference in byte size between the average record byte size and the byte size of the subject record, and wherein the byte size of the subject record is less than the average record byte size;
in response to determining that the received database operation is an update operation that changes a record byte size, increasing or decreasing the preliminary free space byte size, based on the update increasing or decreasing the record byte size, respectively, based on a third difference in byte size between the average record byte size and the byte size of the subject record, and wherein the byte size of the subject record is less than the average record byte size; and
allocating free space at a page level of the database table based on the primary free space byte size.

Assignees

• IBM

Inventors

• Fang Min
• Jin Di
• Shi Zhenyu
• Slinger Nigel G
• Wang Shu
• Zheng li fei
• Zhu wen jie

Classifications

• G06F16/215 Primary

  Improving data quality; Data cleansing, e.g. de-duplication, removing invalid entries or correcting typographical errors · CPC title

• G06F16/162

  Delete operations (erasing in storage systems G06F3/0652) · CPC title

• G06F16/21

  Design, administration or maintenance of databases · CPC title

• G06F17/30289

  Physics · mapped topic

• G06F17/30117

  Physics · mapped topic