In-memory database system providing lockless read and write operations for OLAP and OLTP transactions

US10127260B2 · kind B2 · utility

Assignee

• SAP SE · DE

Inventors

• Anil Kumar Goel · Waterloo, CA
• Ivan Schreter · Malsch, DE
• Juchang Lee · Seoul, KR
• Mihnea Andrei · Issy-les-Moulineaux, FR
• Steffen Geissinger · Wiesloch, DE
• Thomas Legler · Walldorf, DE

Key dates

• Filing date: Nov 25, 2014
• Grant date: Nov 13, 2018
• Expiry date: Dec 27, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F16/283
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

As part of a database system comprising a combination of on-disk storage and in-memory storage, a plurality of records that comprise a table are stored in a plurality of fragments that include at least a delta fragment and a main fragment retained in the on-disk storage. Each fragment has visibility data structures to enable multi-version concurrency control. Each fragment can be compressed using dictionary compression and n-bits compression. The fragments are loaded into main system memory in the in-memory storage from the on-disk storage if they are accessed for read operations or write operations and are not already in memory. A plurality of lockless read and write operations are concurrently performed, while providing snapshot isolation, on the at least one of the plurality of fragments while the at least one of the plurality of fragments is in the main system memory.