Locking concurrent commands in a database management system

US10585874B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Bjoern Broll · Waldenbuch, DE
• Sabine Perathoner-Tschaffler · Nufringen, DE
• Stefan Renner · Leonberg, DE
• Knut Stolze · Jena, DE

Key dates

• Filing date: Aug 1, 2016
• Grant date: Mar 10, 2020
• Expiry date: Jun 24, 2038

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F16/2365
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

Disclosed herein are methods for receiving a command for adding or removing a resource in a database and acquiring an exclusive lock for the database in response the command. In response to obtaining the exclusive lock, the method comprises determining a first number indicating the number of resources currently existing in the database and a second number indicating the number of resources subject to concurrent further commands for adding or removing a resource; comparing the first and the second number for determining whether the received command will remove the last existing resource or add a first resource to the database; and obtaining an exclusive or a shared lock for the received command in dependence on the determination. The method further includes releasing the exclusive lock for the database and adding or removing the resource while holding the lock obtained for the received command.