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Virtual Storage Access Method z/OS DFSMS Using Data Sets SC23-6855-00 |
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VSAM arranges records by an index key, relative record number,
or relative byte addressing. VSAM is used for direct or sequential
processing of fixed-length and variable-length records on DASD. Data
that is organized by VSAM is cataloged for easy retrieval and is stored
in one of five types of data sets.
Any type of VSAM data set can be in extended format. Extended-format data sets have a different internal storage format than data sets that are not extended. This storage format gives extended-format data sets additional usability characteristics and possibly better performance due to striping. You can choose for an extended-format key-sequenced data set to be in the compressed format. Extended-format data sets must be SMS managed. You cannot use an extended-format data set for certain system data sets. Requirement: Do not use BISAM or QISAM. Use VSAM instead. |
Copyright IBM Corporation 1990, 2014
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