An entry-sequenced data set (ESDS) is a type of data set used by IBM's VSAM computer data storage system.[1]: 5  Records are accessed based on their sequential order, that is, the order in which they were written to the file; which means that accessing a particular record involves searching all the records sequentially until it is located, or by using a relative physical address (Relative byte address, RBA), i.e. the number of bytes from the beginning of the file to start reading.[1]: 28 

Keys may be used to access records in an ESDS by defining an alternate index.[1]: 15 

See also

References

"MVS Forums - Technical FAQ's - VSAM". Mvsforums.com. Retrieved 12 December 2017.

  1. 1 2 3 Lovelace, Mary; Dovidauskas, Jose; Salla, Alvaro; Sokal, Valeria (March 2013). "Chapter 1. VSAM basics". VSAM Demystified (PDF). Redbooks (3 ed.). IBM.


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