Dynamic selection of query execution operators

US10521430B1 · kind B1 · utility

Assignee

• Tableau Software, Inc. · US

Inventors

• Michael Schreier · Munich, DE
• Thomas Neumann · Munich, DE
• Viktor Leis · Munich, DE
• Alfons Kemper · Munich, DE
• Tobias Muehlbauer · Munich, DE
• Jan Finis · Munich, DE

Key dates

• Filing date: Jul 14, 2017
• Grant date: Dec 31, 2019
• Expiry date: Feb 26, 2038

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F16/2455
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A method dynamically selects query execution operators for a database engine. The database engine receives a query and parses the query to form a query execution tree. The engine creates a first executable plan that includes in-memory operators, which execute within the volatile memory. While executing a first in-memory operator, the engine detects insufficient memory to complete the execution and aborts the execution. The engine then recompiles the query execution tree to form a second executable plan, which includes spooling operators. Each spooling operator executes within a fixed volatile memory budget. The engine executes the second executable plan, including the plurality of spooling operators, to identify a set of results from the database that is responsive to the query, and returns the results.