Adaptive dictionary compression/decompression for column-store databases

US10235377B2 · kind B2 · utility

Assignee

• SAP SE · DE

Inventors

• Ingo Mueller · Heidelberg, DE
• Cornelius Ratsch · Heidelberg, DE
• Peter Sanders · Bath, GB
• Franz Faerber · Walldorf, DE

Key dates

• Filing date: Dec 23, 2013
• Grant date: Mar 19, 2019
• Expiry date: Dec 12, 2034

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F16/221
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

Innovations for adaptive compression and decompression for dictionaries of a column-store database can reduce the amount of memory used for columns of the database, allowing a system to keep column data in memory for more columns, while delays for access operations remain acceptable. For example, dictionary compression variants use different compression techniques and implementation options. Some dictionary compression variants provide more aggressive compression (reduced memory consumption) but result in slower run-time performance. Other dictionary compression variants provide less aggressive compression (higher memory consumption) but support faster run-time performance. As another example, a compression manager can automatically select a dictionary compression variant for a given column in a column-store database. For different dictionary compression variants, the compression manager predicts run-time performance and compressed dictionary size, given the values of the column, and selects one of the dictionary compression variants.