Allocating free space in a database

Patent metadata

Field	Value
Publication number	US-10248673-B2
Application number	US-201615078173-A
Country	US
Kind code	B2
Filing date	Mar 23, 2016
Priority date	Mar 23, 2016
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

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, 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, and wherein the subject record is subjected to the received database operation;
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.

2. The method in accordance with claim 1 , 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.

3. The method in accordance with claim 1 , wherein determining the primary free space byte size is in response to commencing a database utility.

4. The method in accordance with claim 3 , wherein the database utility is associated with at least one of a reorganization process or a page loading process.

5. A computer system for allocating free space in a database table associated with a relation database managed by a relational database management system, the computer system comprising:
one or more computer processors, one or more non-transitory computer-readable storage media, and program instructions stored on one or more of the computer-readable storage media for execution by at least one of the one or more processors, the program instructions comprising:
program instructions to receive statistics associated with records in a database table, wherein the statistics include an average record byte size for records stored in the database table;
program instructions to receive a database operation, wherein the received database operation comprises an insertion operation, a deletion operation, and an update operation;
program instructions to determine a primary free space byte size for record updates, 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, and wherein the subject record is subjected to the received database operation;
in response to determining that the received database operation is an insertion operation, program instructions to increase 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, program instructions to decrease 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, program instructions to increase or decrease 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
program instructions to allocate free space at a page level of the database table, based on the primary free space byte size.

6. The computer system in accordance with claim 5 , wherein program instructions to determine the primary free space byte size further comprise program instructions to modify the preliminary free space byte size based on the average record byte size and the byte size of the subject record.

7. The computer system in accordance with claim 5 , wherein program instructions to determine the primary free space byte size are executed in response to commencing a database utility.

8. The computer system in accordance with claim 7 , wherein the database utility is associated with at least one of a reorganization process or a page loading process.

Assignees

• IBM

Inventors

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

Classifications

• G06F16/21

  Design, administration or maintenance of databases · CPC title

• 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

• G06F17/30303 Primary

  Physics · mapped topic

• G06F17/30289

  Physics · mapped topic