Jump to content

Linear data set

From Wikipedia, the free encyclopedia
(Redirected from Linear Data Set)

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
  1. ^ a b Lovelace, Mary; Dovidauskas, Jose; Salla, Alvaro; Sokal, Valeria (August 2022). "Chapter 1. VSAM basics". VSAM Demystified (PDF). Redbooks (3 ed.). IBM.
  2. ^ "Linear Data sets" (PDF). z/OS 2.5 DFSMS Using Data Sets (PDF). IBM. September 30, 2021. p. 91. SC23-6855-50.
  3. ^ "IBM Knowledge Center". www.ibm.com. 27 March 2014. Retrieved 2021-02-07.
  4. ^ ASMGUIDE, pp. 225-248, Chapter 14. Data-in-virtual.
  5. ^ ASMGUIDE, pp. 293-310, Chapter 17. Window Services.