What is QSAM file?

Queued sequential access method (QSAM) files are unkeyed files in which the records are placed one after another, according to entry order. Your program can process these files only sequentially, retrieving (with the READ statement) records in the same order as they are in the file.

How do I create a Qsam file?

Create and Populate a QSAM File The first step in the job executes IEFBR14 with a DD statement that has a DISP=(MOD,DELETE,DELETE). This step will delete a previously created file with the same name. The second step in the job executes IEBGENER. The data for populating the QSAM file is contained within the JCL member.

What is QSAM in mainframe?

VSAM or Virtual Storage Access Method is a file storage access method used in MVS, ZOS, and OS/390 operating systems. It was introduced by IBM in 1970’s. It’s a high-performance access method to organize data as files in mainframes. VSAM is used by programming languages in mainframes to store and retrieve data.

What is the difference between VSAM and Qsam?

VSAM files are always mainframe files, but most mainframe files are not VSAM. QSAM (Queued Sequential Access Method) is probably the most common access method for mainframe files. QSAM files are often called “flat files”, because they have no index structure built on top of the data.

Which is an example of a QSAM file?

Many of the sample programs access a QSAM or sequential file. This file is created by running an MVS batch job using a single mainframe JCL member. Note-1: rseq = a Record Sequential File, this example uses 80-byte, fixed length records.

How to access a QSAM file using COBOL?

QSAM or Sequential File Access using COBOL called by COBOL This program example describes how a mainline COBOL program calls a COBOL I/O routine to access a QSAM or Sequential file. The COBOL programs are written using COBOL/2 dialect but also works with COBOL for OS390.

How does queued sequential access method ( QSAM ) work?

Queued sequential access method (QSAM) files are unkeyed files in which the records are placed one after another, according to entry order. Your program can process these files only sequentially, retrieving (with the READ statement) records in the same order as they are in the file. Each record is placed after the preceding record.

How to populate VSAM, populate QSAM KSDS?

Read QSAM, Populate VSAM KSDS. On the Linux, UNIX or Windows platforms the data file names and source member names typically have file extensions. When uploaded to the mainframe from the PC the file extension is dropped. This suite of programs, data sets and documentation are available in a single zipped file referred to as a zPack.