Editing Data set (IBM mainframe) (section)

==Data set organization==
For OS/360, the DCB's <code>DSORG</code> parameter specifies how the data set is organized. It may be<ref>{{cite manual
 |       title = IBM System/3S0 Operating System: Job Control Language Reference - OS Release 21.7 
 |         id = GC28-6704-4
 |     section = Section IV: The DD Statement -- DCB Parameter 
 | section-url = http://bitsavers.org/pdf/ibm/360/os/R21.7_Apr73/GC28-6704-4_OS_JCL_Aug76.pdf#page=138
 |       pages = 138–139
 |         url = http://bitsavers.org/pdf/ibm/360/os/R21.7_Apr73/GC28-6704-4_OS_JCL_Aug76.pdf
 |      series = IBM Systems Reference Library
 |   publisher = IBM
 }}
</ref>
;CQ
:[[Queued Telecommunications Access Method]] (QTAM) in Message Control Program (MCP)
;CX
:Communications line group
;DA
:[[Basic Direct Access Method]] (BDAM)
;GS
:Graphics device for Graphics Access Method(GAM)
;IS
:[[Indexed Sequential Access Method]] (ISAM)
;MQ
:QTAM message queue in application
;PO
:Partitioned Organization
;PS
:Physical Sequential
among others.
Data sets on tape may only be <code>DSORG=PS</code>. The choice of organization depends on how the data is to be accessed, and in particular, how it is to be updated.

Programmers utilize various [[access method]]s (such as [[Queued Sequential Access Method|QSAM]] or [[VSAM]]) in programs for reading and writing data sets. Access method depends on the given data set organization.