Key Sequenced Data Set

A Key Sequenced Data Set (KSDS) is a type of data set used by the IBM VSAM computer data storage system. Each record in a KSDS data file is embedded with a unique key. A KSDS consists of two parts, the data component and a separate index file known as the index component which allows the system to physically locate the record in the data file by its key value. Together, the data and index components are called a cluster.