PIVOT and UNPIVOT: Optimization and Execution Strategies in an RDBMS and Scalable Pull-Based Caching for Erratic Data Sources Conor Cunningham, César A. Galindo-Legaria, and Goetz Graefe   View Paper (PDF)   Return to INDUSTRIAL SESSION 1: NOVEL SQL EXTENSIONS Abstract 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. ©2005 Association for Computing Machinery