Access Method

Access methods provide a convenient service to programmers for managing data storage and transmission. While providing the programmer with flexibility, the abstraction hides the many details regarding low-level disk access and communication protocol operations.

Access methods include internal structures to organize data as data sets, system-provided programs or macros to define data sets, and utility programs for data set processing. Error detection and correction capabilities are also provided.

Storage-oriented access methods include:

• Basic direct access method (BDAM)
• Basic sequential access method (BSAM)
• Basic partitioned access method (BPAM)
  
• Queued sequential access method (QSAM)
• Indexed sequential access method (ISAM)
• Virtual storage access method (VSAM)
• Object access method (OAM)

Network-oriented access methods include:

• Basic telecommunications access method (BTAM)
• Queued teleprocessing access method (QTAM)
• Telecommunications access method (TCAM)
• Virtual telecommunications access method (VTAM)
• Channeled access method (CAM)