Elimination of query fragment duplication in complex database queries

US11475005B2 · kind B2 · utility

Assignee

• Tableau Software, Inc. · US

Inventors

• Adrian Vogelsgesang · Munich, DE
• Michael Haubenschild · Erding, DE
• Richard L. Cole · Los Gatos, US
• Jan Finis · Munich, DE
• Manuel Then · Munich, DE
• Tobias Muehlbauer · Munich, DE
• Thomas Neumann · Munich, DE

Key dates

• Filing date: Oct 6, 2020
• Grant date: Oct 18, 2022
• Expiry date: Oct 6, 2040

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F16/2454
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A database engine includes one or more computing devices, each having one or more processors and memory. The memory stores programs configured for execution by the processors. The database engine receives a database query from a client, and parses the database query to build a query operator tree. The query operator tree includes a plurality of query operators. The database engine performs one or more optimization passes on the query operator tree, including a deduplication optimization pass, to form an optimized execution plan. The deduplication optimization pass includes determining that a first query operator is equivalent to a second query operator during a traversal of the query operator tree, and replacing the second query operator with a link to reuse results from the first query operator. The database engine executes the optimized execution plan to retrieve a result set from the database and returns the result set to the client.