Virtual Storage Access Method (VSAM) [1] is an IBM direct-access storage device (DASD) file storage access method, first used in the OS/VS1, OS/VS2 Release 1 (SVS) and Release 2 (MVS) operating systems, later used throughout the Multiple …

There are three types of VSAM data sets. Each type roughly corresponds to a PL/I data set organization. All three types of VSAM data sets are ordered, and they can all have keys associated with their records. Both sequential and keyed access are possible with all three types.

VSAM Tutorial - VSAM is abbreviated as Virtual Storage Access Method. VSAM is high performance access method and data set organization, which organizes and maintains data in a catalog structure.

Use an entry in the FILE-CONTROL paragraph in the ENVIRONMENT DIVISION to define the file organization and access modes for the VSAM files in your COBOL program.

VSAM is the short form of Virtual Storage Access Method. VSAM was introduced in the early 1970s by IBM with three dataset organizations - sequential, indexed, and direct access. It has been continuously improved and enhanced from 1970.

You can use VSAM to organize records into four types of data sets: key-sequenced, entry-sequenced, linear, or relative record. The primary difference among these types of data sets is the way their records are stored and accessed.

While developing VSAM, the designing team defined some basic important concepts and terms. Before learning more about VSAM, knowing about these concepts and terms will be helpful. Those are - A VSAM cluster is a logical definition for a VSAM dataset and has the below one or two components - The data component contains the data records.

Learn about Virtual Storage Access Method (VSAM) in this comprehensive tutorial, covering its features, types, and usage in mainframe environments.

Feb 19, 2020 · This article will take you inside VSAM and explain the environment of Virtual Storage Access Method. VSAM has been around since the 1970s and provides a way of storing large amounts of data for 3 types of access. VSAM has a number of different structures.

Nov 21, 2019 · VSAM is a multifunction, all-purpose access method. VSAM is different from the other data set types because it provides a functional equivalent for most of the other data set organizations, as follows: ESDS organization is the functional equivalent of Physical Sequential organization (PS).