Parallel Query Processing Different queries/transactions can be run in parallel with each other. Interquery parallelism Concurrency control takes care of conflicts in case of updates More on parallel transaction processing in Chapter 23 Focus in this chapter is on read-only queries Individual relational operations (e.g.,sort,join,aggregation)can be executed in parallel data can be partitioned and each processor can work independently on its own partition. Queries are expressed in high level language (SQL,translated to relational algebra) makes parallelization easier. Database System Concepts-7th Edition 22.3 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 22.3 ©Silberschatz, Korth and Sudarshan th Edition Parallel Query Processing ▪ Different queries/transactions can be run in parallel with each other. • Interquery parallelism • Concurrency control takes care of conflicts in case of updates • More on parallel transaction processing in Chapter 23 • Focus in this chapter is on read-only queries ▪ Individual relational operations (e.g., sort, join, aggregation) can be executed in parallel • data can be partitioned and each processor can work independently on its own partition. ▪ Queries are expressed in high level language (SQL, translated to relational algebra) • makes parallelization easier