Mapping logical row identifiers for primary B+tree-like structures to physical row identifiers

US6859808B1 · kind B1 · utility

Assignee

• Oracle International Corporation · US

Inventors

• Eugene Inseok Chong · Concord, US
• Jagannathan Srinivasan · Nashua, US
• Souripriya Das · Nashua, US
• Charles G. Freiwald · Amherst, US
• Aravind Yalamanchi · Nashua, US
• Mahesh Jagannath · Shrewsbury, US
• Anh Tuan Tran · Vacaville, US
• Ramkumar Krishnan · Gilbert, US

Key dates

• Filing date: May 31, 2001
• Grant date: Feb 22, 2005
• Expiry date: Jun 27, 2022

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S707/99943
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A mapping mechanism for a primary B+tree in a database management system. The primary B+tree includes a plurality of rows. The mapping mechanism includes introducing a mapping table that includes a plurality of rows, including a row for each row of the primary B+tree, and that stores the logical identifier of the corresponding primary B+tree row. In addition, reverse mapping is provided by augmenting a primary B+tree to include in each primary B+tree row a physical row identifier of the corresponding mapping table row. An auxiliary structure created on a primary B+tree can make use of the proposed mapping mechanism. Specifically, the auxiliary structures refers to primary B+tree rows indirectly by storing the physical row identifier of the corresponding mapping table row.