Data compression method and apparatus
US6965897B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 25, 2002 |
| Grant date | Nov 15, 2005 |
| Priority date | — |
| Expiry date | Aug 10, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99945
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved data compression method and apparatus is disclosed, particularly for compressing large database tables. A data structure is disclosed which is fully compatible with the traditional DBMS demands, including the random access requirement of RDBMS. The data structure is built on a mixed format physical layout comprising of fixed-sized fields and variable-sized fields which are compressed depending on the size and frequency of the fields. An improved compression ratio is achieved by exploiting redundancy in the mixed format physical layout to encode the column-wise redundancy in the data itself and the correlations among columns. The present invention provides a very fast random access decompression and enables not only greater compression ratios, but also permits flexibility of choosing from a number of compression algorithms.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.