Linear data set explained

A linear data set (LDS) is a type of data set organization used by IBM's VSAM computer data storage system.[1]

The LDS has a control interval size of 4096 bytes to 32768 bytes[2] in increments of 4096.[1] 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. 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. Data In Virtual (DIV) and Window services provide an alternative method to direct use of VSAM to access an LDS with a CI size of 4096.

See also

References

ASMGUIDE
  • z/OS 2.5 MVS Programming: Assembler Services Guide . SA23-1368-50 . September 30, 2021 . . IBM .
    Other citations

    Notes and References

    1. Book: VSAM Demystified . Redbooks . Mary . Lovelace . Jose . Dovidauskas . Alvaro . Salla . Valeria . Sokal . Chapter 1. VSAM basics . 3 . IBM . August 2022.
    2. z/OS 2.5 DFSMS Using Data Sets . SC23-6855-50 . Linear Data sets . https://www-01.ibm.com/servers/resourcelink/svc00100.nsf/pages/zOSV2R5sc236855/$file/idad400_v2r5.pdf#page=126 . 91 . September 30, 2021 . IBM .
    3. Web site: IBM Knowledge Center. 2021-02-07. www.ibm.com. 27 March 2014 . en-US.