Editing Virtual Storage Access Method (section)

== Data access techniques ==
There are four types of access techniques for VSAM data:

* Local Shared Resources (LSR), is optimised for "random" or direct access. LSR access is easy to achieve from [[CICS]].<ref name=VSAM.LSRorNSR>{{cite web
   |url=https://www.ibm.com/support/knowledgecenter/SSGMCP_5.6.0/tuning/dfht3c00200.html
   |title=Local shared resources (LSR) or nonshared resources|website=[[IBM]] }}</ref>
* Global Shared Resources (GSR)<ref name=VSAM.GSR>{{cite web  |website=IBM.com (IBM Knowledge Center)
      |url=https://www.ibm.com/support/knowledgecenter/SSLTBW_2.3.0/com.ibm.zos.v2r3.idad400/share.htm
      |quote=describes considerations for sharing VSAM data sets for NSR or LSR/GSR
      |title=Sharing VSAM Data Sets}}</ref>
* Non-Shared Resources (NSR), which is optimised for sequential access. NSR access has historically been easier to use than LSR for batch programs.<ref name=VSAM.LSRorNSR/>
* Distributed File Management (DFM), an implementation of a [[Distributed Data Management Architecture]] server, enables programs on remote computers to create, manage, and access VSAM files.