PIVOT and UNPIVOT: Optimization and Execution Strategies in an RDBMS

PIVOT and UNPIVOT, two operators on tabular data that exchange rows and columns, enable data transformations useful in data modeling, data analysis, and data presentation. They can quite easily be implemented inside a query processor, much like select, project, and join. Such a design provides opportunities for better performance, both during query optimization and query execution. We discuss query optimization and execution implications of this integrated design and evaluate the performance of this approach using a prototype implementation in Microsoft SQL Server.

• Type: Conference
• Year: 2004
• Where: VLDB
• Authors: Conor Cunningham, Goetz Graefe, César A. Galindo-Legaria
• Keywords: Database, Enable Data Transformations, Query Optimization, Query Processor, VLDB 2004