Data Compression For Reducing Storage Requirements in a Database System

• US 20100325094A1
• Filed: 06/19/2009
• Published: 12/23/2010
• Est. Priority Date: 06/19/2009
• Status: Active Grant

• Current Assignee: Sybase Incorporated (SAP SE)
• Original Assignee: Sybase Incorporated (SAP SE)
• Inventors: YANG, Xinjun, Qian, Xudong
• Granted Patent: US 8,706,727 B2
• Time in Patent Office: Days
• US Class Current: 707/693
• CPC Class Codes: G06F 16/22 Indexing; Data structures therefor; Storage structures

Abstract

A system, method, and computer program product for reducing data storage requirements in a database system are described herein. An embodiment includes identifying at least one data candidate of fixed length data type in at least one row of database data for compression based upon a predetermined threshold level and a boundary of compression, providing at least one bit within the at least one row for an identified data candidate according to the boundary of compression, and storing the at least one row as compressed data in the database system. For compression based on a row boundary, the identified data candidates for compression include fixed length columns having lengths that do not fall below the predetermined threshold level in a row of data and the at least one bit comprises a bitmap for a length of the identified data candidates following compression. For compression based on a page boundary, the identified data candidates for compression include redundant byte string data in a page of data, the redundant byte string data including matching data across columns having lengths that do not exceed the predetermined threshold level.

Claims

1. A method for reducing data storage requirements in a database system, the method comprising:

a. identifying at least one data candidate of fixed length data type in at least one row of database data for compression based upon a predetermined threshold level and a boundary of compression;

b. providing at least one bit within the at least one row for an identified data candidate according to the boundary of compression; and

c. storing the at least one row as compressed data in the database system.

2. The method of claim 1 wherein identified data candidates for compression comprise fixed length columns having lengths that do not fall below the predetermined threshold level in a row of data for compression based on a row boundary.

3. The method of claim 2 wherein the at least one bit comprises a bitmap for a length of identified data candidates following compression.

4. The method of claim 1 wherein identified data candidates for compression comprise redundant byte string data in a page of data for compression based on a page boundary.

5. The method of claim 4 wherein the redundant byte string data comprises matching data across columns having lengths that do not exceed the predetermined threshold level.

6. The method of claim 5 wherein the at least one bit comprises at least one bit in a row status to indicate compression of the identified data candidate.

7. The method of claim 4 further comprising extracting the redundant byte string data into a page index.

8. The method of claim 7 wherein the page index supplements a page dictionary for the page of data.

9. The method of claim 1 wherein the boundary of compression comprises a row boundary and a page boundary.

10. The method of claim 1 wherein the predetermined threshold level comprises a column length.

11. The method of claim 1 wherein the predetermined threshold level sets opposing limits depending upon the boundary of compression.

12. A system capable of reducing data storage requirements in a database system, the system comprising:

a. storage means;

b. processing means coupled to the storage means; and

c. database management means coupled to the storage means and controlled by the processing means, the database management means identifying at least one data candidate of fixed length data type in at least one row of database data for compression based upon a predetermined threshold level and a boundary of compression, providing at least one bit within the at least one row for an identified data candidate according to the boundary of compression, and storing the at least one row as compressed data in the storage means.

13. The system of claim 12 wherein identified data candidates for compression comprise fixed length columns having lengths that do not fall below the predetermined threshold level in a row of data for compression based on a row boundary.

14. The system of claim 13 wherein the at least one bit comprises a bitmap for a length of identified data candidates following compression.

15. The system of claim 12 wherein identified data candidates for compression comprise redundant byte string data in a page of data for compression based on a page boundary.

16. The system of claim 15 wherein the redundant byte string data comprises matching data across columns having lengths that do not exceed the predetermined threshold level.

17. The system of claim 16 wherein the at least one bit comprises at least one bit in a row status to indicate compression of the identified data candidate.

18. The system of claim 12 wherein the predetermined threshold level comprises a column length.

19. The system of claim 12 wherein the predetermined threshold level sets opposing limits depending upon the boundary of compression.

20. A computer program product comprising a computer usable medium having computer program logic recorded thereon for enabling a processor to reduce data storage requirements in a database system, the computer program logic comprising:

means for identifying at least one data candidate of fixed length data type in at least one row of database data for compression based upon a predetermined threshold level and a boundary of compression;

means for providing at least one bit within the at least one row for an identified data candidate according to the boundary of compression; and

storage means for storing the at least one row as compressed data in the database system.