VSAM – Catalog

Catalog maintains the unit and volume where dataset resides. Catalog is used for retrieval of datasets. Non-VSAM datasets create a catalog entry by means of Disposition Parameter in JCL. VSAM…

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VSAM – Commands

VSAM commands are used to perform certain operations on VSAM datasets. Following are the most useful VSAM commands โˆ’ AlterReproListcatExamineVerify Alter ALTER command is used to modify VSAM file attributes.…

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VSAM – LDS

LDS is known as Linear Data Set. Linear dataset is the only form of byte-stream dataset which is used in used in traditional operating system files. Linear datasets are rarely…

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VSAM – RRDS

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RRDS is known as Relative Record Data Set. RRDS cluster is similar to an ESDS cluster. The only difference is that RRDS records are accessed by Relative Record Number (RRN), we…

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VSAM – KSDS

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KSDS is known as Key Sequenced Data Set. A key-sequenced data set (KSDS) is more complex than ESDS and RRDS but is more useful and versatile. We must code INDEXED inside the…

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VSAM – ESDS

ESDS is known as Entry Sequenced Data Set. An entry-sequenced data set behaves like sequential file organization with some more features included. We can access the records directly and for…

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VSAM – Cluster

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VSAM cluster is defined in JCL. JCL uses IDCAMS utility to create a cluster. IDCAMS is a utility, developed by IBM, for access method services. It is used to primarily define VSAM datasets.…

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