This document provides information on purpose, use and maintenance of a Natural scratch-pad file.
The following topics are covered:
The scratch-pad file is just another Natural system file like
FNAT and
FUSER, and has the
same physical file layout. It enables the storage of, for example, saved screen
images and other types, data which are not stored explicitly like Natural
sources, objects (SAVE,
CATALOG,
STOW)
and error messages, on a file other than the system file FNAT or
FUSER.
In contrast to FNAT and FUSER, a scratch-pad
file is not mandatory in a Natural session.
However, if you are working with read-only access to system files
(profile parameter ROSY=ON), you
must define a scratch-pad file, because otherwise the above mentioned
data could not be stored and a corresponding error message (NAT0106) would be
issued instead. The scratch-pad file is excluded from read-only access.
Like all other system files of Software AG products, the scratch-pad file is a logical file. The logical file number of the scratch-pad file is 212.
Since there is no mnemonic for the scratch-pad file such as
FNAT and
FUSER or
FDIC, it has to be
defined:
either statically by using the macro
NTLFILE
in the Natural parameter module NATPARM or
dynamically by using the profile parameter
LFILE.
NTLFILE and
LFILE definition:
LFILE Parameter:
LFILE=(212,physical-dbid,physical-fnr,password,cipher-key)
NTLFILE Macro:
NTLFILE 212,physical-dbid,physical-fnr,password,cipher-key
The objects that are stored on the scratch-pad file are:
As the amount of usage of the Recording Utility and the
NATPAGE utility
cannot be calculated beforehand, a reasonable estimate about the related
storage requirements is hardly possible. However, the scratch-pad file size
required at your site can be estimated with a better understanding of the types
of records that are stored on it.
The Recording Utility is activated using terminal commands as described in the Utilities documentation. Recordings are stored like Natural source programs (or other object types). The size of a recording depends on how many screen inputs have been done during a recording session. Recordings are like programs related to a library.
Currently, it is not possible to list recordings on the scratch-pad
file by using the Natural LIST system
command. SYSMAIN can be used, though, to list and maintain the
recordings stored on the scratch-pad file. To store the recordings on the
FNAT/FUSER file instead of on the scratch-pad file, set the
profile parameter RFILE.
Recordings which are being stored on the system file FNAT
or FUSER are affected (interrupted) by transaction backouts (BTs)
which are issued in the user's application programs. This is a very common
problem encountered by users of the recording facility and it can be avoided by
using the scratch-pad file.
The screen paging utility NATPAGE can be used to store
screen images (in chronological sequence of their appearance) on the
scratch-pad file. NATPAGE can be activated with the terminal
command %P. From the moment
%P is issued, all screens presented to the end user
are stored onto the scratch-pad file (if it has been defined for your session)
until the terminal command %O is entered. The
captured screens can be displayed using the terminal command
%E.
For each screen image, the current content of the page buffer and the
page attribute buffer is stored. This means that the amount of data being
stored depends on the settings of the profile parameters
PS/LS for the session and,
of course, on the number of screen images. The number of possible screens per
user session depends on the profile parameter PD (default is 50;
valid values are 0-255).
The size of the page buffer can be calculated as:
PS * LS
The size of the page attribute buffer is determined dynamically.
The scratch-pad file does not need any maintenance, provided it is of sufficient size.
Recordings on the scratch-pad file can be deleted, copied, moved and
listed by using the utility SYSMAIN.
Captured screens can be deleted by using the
%E
terminal command.
Saved screen images, however, cannot be maintained in Natural at all.
Space on the scratch-pad file can be reclaimed by refreshing it with Adabas utilities in times of non-activity without affecting subsequent Natural sessions which are using the scratch-pad file.