Linear data set
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A linear data set (LDS) is a type of data set organization used by IBM's VSAM computer data storage system.[1]: 5
The LDS has a control interval size of 4096 bytes to 32768 bytes[2] in increments of 4096.[1]: 31 A LDS does not have embedded control information, because it does not contain control information, the LDS cannot be accessed as if it contained individual records.[3]
Addressing within an LDS is by Relative Byte Address (RBA), which allows it to be used by systems such as IBM Db2 or the Operating system.[clarification needed] The benefit of this is that systems such as the OS can access multiple disk spindles and view it as a single storage implementation. The limitations of this, though, is that this does not make this particularly useful to higher level abstraction levels.[original research?] Data In Virtual[4] (DIV) and Window services[5] provide an alternative method to direct use of VSAM to access an LDS with a CI size of 4096.
See also
[edit]References
[edit]- ASMGUIDE
- z/OS 2.5 MVS Programming: Assembler Services Guide (PDF). IBM. September 30, 2021. SA23-1368-50.
- Other citations
- ^ a b Lovelace, Mary; Dovidauskas, Jose; Salla, Alvaro; Sokal, Valeria (August 2022). "Chapter 1. VSAM basics". VSAM Demystified (PDF). Redbooks (3 ed.). IBM.
- ^ "Linear Data sets" (PDF). z/OS 2.5 DFSMS Using Data Sets (PDF). IBM. September 30, 2021. p. 91. SC23-6855-50.
- ^ "IBM Knowledge Center". www.ibm.com. 27 March 2014. Retrieved 2021-02-07.
- ^ ASMGUIDE, pp. 225-248, Chapter 14. Data-in-virtual.
- ^ ASMGUIDE, pp. 293-310, Chapter 17. Window Services.