What is the difference between VSAM and non-VSAM?

VSAM files require the utility to create, edit and delete the file. Non-VSAM files can be created, edited, and deleted using the ISPF facility. Only works with data stored on disk and can’t handle data stored on other devices like tapes. Files can store on both disks and tapes.

What is non-VSAM?

Non-VSAM data sets are collections of fixed-length or variable-length records, grouped into blocks. To access non-VSAM data sets, use BSAM, QSAM, or BPAM. There are several types of non-VSAM data sets: Sequential data set (PS) Contains records that are stored in physical order.

How do I view VSAM data?

Aaru wrote: We use FILEAID to view a VSAM file. Type FA on the command prompt and see if it is available in your shop.

What is the difference between flat files and VSAM files?

FLAT files are sequential read . VSAM files can sequential and random read. In VSAM acess is fast because of organization of records. In FLAT files you can delete the record logicaly where as in VSAM physical delete is possible.

What is RRDS VSAM?

A Relative record dataset has records that are identified by the Relative Record Number (RRN), which is the sequence number relative to the first record. RRDS allows access of records by number like record 1, record 2, and so on.

How do I view VSAM files in file aid?

To open a VSAM file with formatted display in File Aid you need the copybook member name that describes the file. To open the file unformatted, you need nothing but the data set name.

How do you get dataset information for a VSAM file?

REPRO command is used to load data into VSAM dataset. It is also used to copy data from one VSAM data set to another. We can use this command to copy data from sequential file to VSAM file. IDCAMS utility uses REPRO command to load the datasets.

Why do we use VSAM?

VSAM stands for Virtual Storage Access Method. It is a high performance access method used to organize data in form of files in Mainframes. VSAM is used by COBOL and CICS in Mainframes to store and retrieve data. VSAM makes it easier for application programs to execute an input-output operation.

How do you verify a command in VSAM?

Verify command is used to check and fix VSAM files which have not been closed properly after an error. The command adds correct End-Of-Data records to the file. In the above syntax, vsam-file-name is the VSAM dataset name for which we need to check the errors.

How do I obtain more information about a VSAM data set?

A VSAM data set causes the LISTDS command to display only the data set organization (DSORG), which is VSAM. Use the LISTCAT command to obtain more information about a VSAM data set. The volume serial number of the DASD volume on which the data set resides. The data set organization (DSORG).

How does the listds command work in VSAM?

The LISTDS command works differently, depending upon whether the data set is VSAM or non-VSAM. If you are unsure as to whether the data set is VSAM or not, enter the LISTDS command with no operands. A VSAM data set causes the LISTDS command to display only the data set organization (DSORG), which is VSAM.

How to copy data from sequential file to VSAM file?

It should execute with MAXCC = 0 and it will alter the Freespace, Volumes and Keys. REPRO command is used to load data into VSAM dataset. It is also used to copy data from one VSAM data set to another. We can use this command to copy data from sequential file to VSAM file.

What does VSAM-KSDS-name check for?

It checks for index and data components and if any problem is found, the error messages are sent spool. You can check any of the IDCxxxxx messages. In the above syntax, vsam-ksds-name is the VSAM dataset name for which we need to examine index and data part of VSAM cluster.