Parallel Sort Range-Partitioning Sort ■ Choose nodes N,...,Nmm,where m n-1 to do sorting. Create range-partition vector with m-1 entries,on the sorting attributes Redistribute the relation using range partitioning Each node N sorts its partition of the relation locally. Example of data parallelism:each node executes same operation in parallel with other nodes,without any interaction with the others. Final merge operation is trivial:range-partitioning ensures that, if i<j,all key values in node Nare all less than all key values in N Database System Concepts-7th Edition 22.10 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 22.10 ©Silberschatz, Korth and Sudarshan th Edition Parallel Sort Range-Partitioning Sort ▪ Choose nodes N1 , ..., Nm, where m  n -1 to do sorting. ▪ Create range-partition vector with m-1 entries, on the sorting attributes ▪ Redistribute the relation using range partitioning ▪ Each node Ni sorts its partition of the relation locally. • Example of data parallelism: each node executes same operation in parallel with other nodes, without any interaction with the others. ▪ Final merge operation is trivial: range-partitioning ensures that, if i < j, all key values in node Ni are all less than all key values in Nj