I/O Parallelism Reduce the time required to retrieve relations from disk by partitioning The relations on multiple disks. Horizontal partitioning-tuples of a relation are divided among many disks such that each tuple resides on one disk. Partitioning techniques(number of disks =n): Round-robin: Send the /th tuple inserted in the relation to disk i mod n. Hash partitioning: Choose one or more attributes as the partitioning attributes. Choose hash function h with range 0...n-1 Let i denote result of hash function h applied tothe partitioning attribute value of a tuple.Send tuple to disk i. Database System Concepts-6th Edition 18.5 @Silberschatz,Korth and SudarshanDatabase System Concepts - 6 18.5 ©Silberschatz, Korth and Sudarshan th Edition I/O Parallelism Reduce the time required to retrieve relations from disk by partitioning The relations on multiple disks. Horizontal partitioning – tuples of a relation are divided among many disks such that each tuple resides on one disk. Partitioning techniques (number of disks = n): Round-robin: Send the I th tuple inserted in the relation to disk i mod n. Hash partitioning: Choose one or more attributes as the partitioning attributes. Choose hash function h with range 0…n - 1 Let i denote result of hash function h applied tothe partitioning attribute value of a tuple. Send tuple to disk i