Managing data records

Patent metadata

Field	Value
Publication number	US-10678770-B2
Application number	US-201715828565-A
Country	US
Kind code	B2
Filing date	Dec 1, 2017
Priority date	Apr 24, 2015
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

Data records may be managed in a relational database by monitoring, a record length for a first data record in a page of memory, an amount of free space in the page, and a page length. In response to receiving an operator command to replace the first data record with a second data record, a database management system may determine whether an estimated record length of a compressed second data record is outside of the amount of free space in the page. In response to determining the estimated record length of a compressed second data record is outside of the amount of free space in the page, the database management system may determine whether an estimated length of a compressed page is outside of the page length. In response to determining the estimated length of a compressed page is within the page length, the page may be compressed.

First claim

What is claimed is:

1. A computer implemented method for managing data records in a relational database, the method comprising:
receiving an operator command to replace a first data record with a second data record in a relational database, wherein the first data record is associated with a record length, a page of memory, an amount of free space in the page, and a page length of the page;
determining that the record length of the second data record is larger than the amount of free space in the page;
determining an estimated record length of a compressed second data record;
determining that the estimated record length of the compressed second data record is within the amount of free space in the page;
in response to determining that the estimated record length of the compressed second data record is within the amount of free space in the page, compressing the second data record in the relational database; and
replacing the first data record with the compressed second data record.

2. The method of claim 1 , wherein receiving the operator command includes comparing the record length of the second data record with the amount of free space in the page.

3. The method of claim 1 , wherein the operator command corresponds with modifier commands, the modifier commands including update operators.

4. The method of claim 1 , wherein the amount of free space in the page includes reserved or unused space in the page in the relational database.

5. A computer program product for managing data records in a relational database, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions executable by a processor to cause the processor to perform a method comprising:
receiving an operator command to replace a first variable data record with a second variable data record in a relational database, wherein the first variable data record is associated with a record length, a page of memory, an amount of free space in the page, and a page length of the page;
determining that the record length of the second variable data record is larger than the amount of free space in the page;
determining an estimated record length of a compressed second variable data record;
determining, by the processor, that the estimated record length of the compressed second variable data record is within the amount of free space in the page;
in response to determining that the estimated record length of the compressed second variable data record is within the amount of free space in the page, compressing the second variable data record in the relational database; and
replacing the first variable data record with the compressed second variable data record.

6. The computer program product of claim 5 , wherein the operator command corresponds with modifier commands, the modifier commands including update operators.

7. The computer program product of claim 5 , wherein the amount of free space in the page includes reserved or unused space in the page in the relational database.

8. The computer program product of claim 5 , wherein receiving the operator command includes comparing the record length of the second variable data record with the amount of free space in the page.

9. A computer system for managing data records in a relational database, the computer system comprising:
a memory; and
a processor in communication with the memory, wherein the processor is configured to perform a method, the method comprising:
receiving an operator command to replace a first data record with a second data record in a relational database, wherein the first data record is associated with a record length, a page of memory, an amount of free space in the page, and a page length of the page;
determining that the record length of the second data record is larger than the amount of free space in the page;
determining an estimated record length of a compressed second data record;
determining, by the processor, that the estimated record length of the compressed second data record is within the amount of free space in the page;
in response to determining that the estimated record length of the compressed second data record is within the amount of free space in the page, compressing the second data record in the relational database; and
replacing the first data record with the compressed second data record.

10. The computer system of claim 9 , wherein receiving the operator command includes comparing the record length of the second data record with the amount of free space in the page.

11. The computer system of claim 9 , wherein the operator command corresponds with modifier commands, the modifier commands including update operators.

12. The computer system of claim 9 , wherein the amount of free space in the page includes reserved or unused space in the page in the relational database.

Assignees

• IBM

Inventors

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

Classifications

• G06F16/90339

  by using parallel associative memories or content-addressable memories · CPC title

• G06F16/284

  Relational databases · CPC title

• G06F16/2282 Primary

  Tablespace storage structures; Management thereof · CPC title

• G06F16/2365

  Ensuring data consistency and integrity · CPC title

• H03M7/60

  General implementation details not specific to a particular type of compression · CPC title