VSAM

This document covers the following topics:

See also section VSAM in the Predict and Other Systems documentation.

Physical VSAM File - File Type V

Attributes

Note:
Parameters not listed below are described in other sections of this documentation: Parameters common to all object types, for example Keys, are described under Global Attributes. Parameters common to all file types, for example Literal name, are described under Common File Attributes. See also Common Parameters for SQL File Types.

Parameters
Sequence field

The descriptor to be used by Natural for logical sequential reading.

Determines the sequence in which records are delivered by the READ LOGICAL statement.

The function Generate DDM uses this attribute as the default READ LOGICAL field in the Natural data definition module.

VSAM attributes
VSAM DD name This parameter refers to a DD card in batch mode, or to a CICS FCT object. See the Natural Operations documentation.
VSAM file org
Valid values:
K KSDS (key-sequenced data set)
E ESDS (entry-sequenced data set)
R RRDS (relative-record data set)
V VRRDS (Variable-length relative record data set)

The above mentioned file organizations do not use extended VSAM files. This means a four byte *ISN is used to hold the relative byte address (RBA) for ESDS files and the relative record number (RRN) for RRDS and VRRDS files.

F ESDS ext.
S RRDS ext.
L KSDS ext.
W VRRDS ext.

The above mentioned file use extended VSAM files. This means for ESDS, a larger *ISN (up to eight bytes) may be used for VSAMs relative byte address (RBA).

The relative record number (RRN) for extended RRDS and VRRDS files remain four bytes long, but will be displayed using this extended ISN field.

Compressed file
Only applicable to files with organization K (KSDS).
Y The record will be truncated if the trailing byte positions are unused.
Numeric zones Valid entries are C and F. This field affects the representation of positive numbers in packed decimal format. The sign position holds hexadecimal C or F respectively.
Location
Volume 1 - 5 The volume(s) on which the file is located. Up to five volumes can be specified.
Data set attributes
CI size - Data The data control interval size.
CI size - Index The control interval size for the primary index.
Recsize - Min The minimum record size.
Recsize - Max The maximum record size.
Free space The free space to be allocated (in percent).

VSAM Logical Files, VSAM Userviews - File Types L, W and R

Attributes

Note:
Parameters not listed below are described in other sections of this documentation: Parameters common to all object types, for example Keys, are described under Global Attributes. Parameters common to all file types, for example Literal name, are described under Common File Attributes. See also Common Parameters for SQL File Types.

Parameters
VSAM prefix

Only applicable to files of types L and R.

If this field is left blank, the last 3 digits of the file number are taken as the prefix. Otherwise, a string of up to 20 characters can be specified. The records in the corresponding physical VSAM file (type V) whose primary keys begin with the specified prefix string will be considered as belonging to the logical VSAM file. The length of the primary key specified for the logical VSAM file must be equal to the length of the primary key specified for the physical VSAM file minus the length of the prefix.

A dummy field (corresponding to the prefix) preceding the primary key in the logical VSAM file must be defined for the field offsets to be calculated correctly.

Sequence field

The descriptor to be used by Natural for logical sequential reading.

Determines the sequence in which records are delivered by the READ LOGICAL statement.

The GENERATE DDM function will use this field as the default READ LOGICAL field in the Natural data definition module.