The Natural parameters in a VSAM environment are defined in one location:
the Natural standard parameters, contained in the Natural parameter module; see Building a Natural Parameter Module in the Operations documentation,
the Natural parameters specific to VSAM, also contained in the Natural
parameter module; see parameter macro
NTVSAM
in the Parameter Reference documentation.
The Natural parameter module can be edited to conform to your site standards, and then assembled and linked using the appropriate jobs (see Installing Natural for VSAM Installation for z/OS and Installation for z/VSE documentation).
This section covers the following topics:
To be able to run Natural in a VSAM environment, you must include the
profile parameter VSIZE, the
NTDB
and the NTVSAM
macro in your Natural parameter module (see the section Installing
Natural for VSAM in the Installation for
z/OS and Installation for
z/VSE documentation).
VSIZE=72, NTDB VSAM,vsam-dbid NTVSAM
VSIZE=160, FNAT=(vsam-dbid,fnr,dd-name), FUSER=(vsam-dbid,fnr,dd-name), FDIC=(vsam-dbid,fnr,dd-name), FSPOOL=(vsam-dbid,fnr,dd-name), FSEC=(vsam-dbid,fnr,dd-name) NTDB VSAM,vsam-dbid NTVSAM ... SFILE=ON,...
dd-name is the logical name (DD
or DLBL) of the system file; see also Installing Natural for
VSAM in the Installation for
z/OS and Installation for
z/VSE documentation.
Note:
If you use VSAM system files with Natural ISPF, see also the
Natural ISPF documentation.
Below is information on:
VSIZE is a Natural
profile parameter which can also be specified dynamically. It is used to
specify the size of the Natural buffer area for VSAM and defines the maximum
memory usage for the internal tables of the Natural interface to VSAM; the
actual sizes of these tables depend on the values set in the Natural parameter
module (see
Assembling the VSAM-specific Natural Parameter Module).
Possible values are 0, 1 - 512 KB.
If you use the default values specified in the Natural parameter
module, the value of the VSIZE parameter must be at
least 72 KB.
If VSIZE is set to 0, Natural for
VSAM is not available and a corresponding error message is returned when trying
to access VSAM files. Disabling Natural for VSAM leads to slight performance
improvements because of skipping the initialization, relocation and roll
efforts of the Natural interface to VSAM.
The NTDB
macro is used to specify the database numbers that relate to VSAM files; that
is, the logical assignments available for Natural.
The value range of NTDB parameters is described
in the Natural Parameter Reference documentation.
Note:
Ensure that the DBIDs selected in the NTDB macro for
VSAM do not conflict with DBIDs selected for other database management
systems.
The NTVSAM
macro is used to specify the VSAM specific parameters.
The value range of the NTVSAM keyword
subparameters is described in the Natural Parameter
Reference documentation
If the default values supplied in the Natural parameter module do not meet your requirements, you can change the parameter values to suit your environment. The individual VSAM-specific parameters contained in the Natural parameter module are described in the following section.
The VSAM-specific Natural parameter module is created by assembling the macro:
and optionally one or more of the following macros:
If more than one macro is specified, the NTVSAM
macro must be specified first; further macros after the
NTVSAM macro can be specified in any order.
The Natural I/O module for VSAM depends on the actual environment in use.
All available I/O modules are delivered in source form so you can make site-specific modifications and use environment-specific macros and/or precompilers. The I/O module must be linked to the Natural parameter module.
The I/O modules available are:
The NVSCICS module is required for CICS under z/OS or
z/VSE. The module contains the following parameter:
The &FCTRELI parameter indicates whether
the key length and record size of a remote file are correctly defined in the
FCT entry of the Application Owning Region (AOR).
| Possible values | Default value |
|---|---|
0 or 1 |
0 |
When this parameter is set to 1, NVSCICS
assumes a correct FCT entry.
When this parameter is set to 0, NVSCICS
issues dummy commands to force opening of the file in the File Owning Region
(FOR) region and then repeats inquiring for the real values.
If the FCT entry does not contain a key length definition,
NVSCICS uses the key length of the corresponding VSAM DDM.
The NVSMISC module is required in all environments except
for CICS. The module mainly consists of the name of the relocatable module for
z/VSE and the NVMMISC macro, which is used to generate the
NVSMISC I/O interface according to your operating system and/or
TP-monitor environment.
NVSMISC is specified as follows:
name
NVMMISC NONRLS=value
TIMEOUT=value
DSECTS=value
DEFER=value
COMMIT=value
ERROR=value
HFACTOR=value
READINT=value
SMARTS=value
TVS=value |
The name of the relocatable
module must be 8 characters long; the default name is NVSMISCD
(z/VSE only).
The individual parameters are described in the following section; specify these parameters according to your requirements.
This parameter is ignored under z/VSE.
When Natural for VSAM issues an RLS-OPEN for
an RLS file and this file has already been opened in non-RLS mode in this z/OS
session, this parameter specifies whether Natural for VSAM issues an open retry
in a non-RLS mode, or whether an open error occurs.
| Possible values | Default value |
|---|---|
YES/NO |
YES |
This parameter is ignored under z/VSE.
This parameter specifies the time in seconds Natural for VSAM is waiting to obtain a lock on a Natural for VSAM record when a lock on the record is already held by another user. For further details refer to the IBM manual z/OS DFSMS Version 1.6 or higher, Macro Instructions for Data Sets.
| Possible values | Default value |
|---|---|
0 - 10 |
0 |
This parameter only applies in batch mode and under TSO.
This parameter specifies whether write operations to disk are to be deferred in the LSR pool. If so and if the LSR pool becomes full, Natural for VSAM writes to disk those 5% of the pool area which have not been used for the longest time.
| Possible values | Default value |
|---|---|
YES/NO |
NO |
The DSECTS parameter specifies whether the VSAM
system DSECTs are to be listed or not.
| Possible values | Default value |
|---|---|
YES/NO |
NO |
This parameter only applies in batch mode and under TSO.
The COMMIT parameter specifies whether all
non-committed updates in any LSR pool are to be written to disk with each
END TRANSACTION
statement of a user program.
| Possible values | Default value |
|---|---|
YES/NO |
NO |
Note:
The specification of COMMIT=YES increases the I/O rate
considerably.
This parameter issues a Natural initialization error if any DD or DLBL
card is omitted in the runtime JCL (see also the macro
NTVLSR).
| Possible values | Default value |
|---|---|
YES/NO |
YES |
If set to NO, processing is continued and Natural for VSAM
will be initialized.
The HFACTOR parameter specifies a factor for the
creation of ESO Hiperspace buffers. When initializing such a Hiperspace, the
corresponding BLDVRP request may lead to a Natural
error message, in which case the value of HFACTOR must
be reduced.
| Possible values | Default value |
|---|---|
0 - a value where a corresponding Natural error
message is returned
|
100 |
The READINT parameter specifies whether read
integrity for an upgrade set should be granted or not.
| Possible values | Default value |
|---|---|
YES/NO |
NO |
The SMARTS parameter is required if installing
Natural for VSAM under SMARTS and/or in a Complete environment.
| Possible values | Default value |
|---|---|
YES/NO |
NO |
This parameter is ignored under z/VSE. The TVS
parameter specifies the support of DFSMStvs in a z/OS environment.
| Possible values | Default value |
|---|---|
YES/NO |
NO |