HP 3000 Manuals

HP ALLBASE/4GL Developer Reference Manual Vol. 1

Data File Reformat Screen 

This screen allows you to modify the format of an existing KSAM data file
without reentering the data in the file.  You cannot use this screen to
reformat serial data files, HP SQL tables, or HP TurboIMAGE/iX data sets,
but procedures for reformatting HP ALLBASE/SQL tables and HP
TurboIMAGE/iX data sets are provided, under Additional Information.


NOTE  HP ALLBASE/4GL KSAM data files may be defined as having more than
      one record layout per file.  The file reformat utility reformats a
      file according to the definition of the default record layout only.
      You may need to restructure all record layouts for files having
      multiple record layouts.


Screen Image 


            

Field Description 

File Name   Enter the HP ALLBASE/4GL name of the KSAM file to be
reformatted.

The remainder of the fields on this screen are display only fields.  When
you enter the HP ALLBASE/4GL name for the file, the system displays the
MPE/iX file name, file type, key fields in the default record, and the
file description.

When you press the  Commit Data  function key, HP ALLBASE/4GL displays a
message requesting you to confirm the data file reformat request.  Enter
Y to continue, or enter N to abort the file reformat.  If you continue
with the data file reformat process, HP ALLBASE/4GL calls an external
program to reformat the file.


NOTE  HP ALLBASE/4GL needs sufficient disk space for temporary storage of
      both the current file and the new file during the reformatting
      process.


Function Keys 

f1       File Defn  Cancels the current screen and displays the file
        definition screen.

f2       Create File  Cancels the current screen and displays the file
        creation screen.

f4       Delete File  Cancels the current screen and displays the file
        deletion screen.

f6       Commit Data  Reformats the named file.

Additional Information 

HP ALLBASE/4GL reformats the file to reflect changes made to the default
record layout for the file.  The file reformat screen allows you to
reformat a data file to reflect changes made to characteristics such as
length, type, justification, and number of decimal places for the fields
in the default record layout for the file.

You can also use this screen to reformat a data file if you have added
new fields, repositioned fields, or deleted fields in the default record
layout.  New fields are initialized with the pad character defined for
that field.

You must generate the redefined default record layout before you use this
screen to reformat a data file.


NOTE  To reformat a KSAM data file under the MPE/iX operating system you
      must be the owner of the file.  The reformat process will fail if
      you are not the owner of the file.


When you press the  Commit Data  function key to reformat the file, HP
ALLBASE/4GL calls an external file utility program.  The file reformat
utility will fail if a file-structure file exists in the group and
account specified by the variable HP4FSPATH. This file-structure file is
part of the automatic run-time data file reformatting system.  It may
exist if a run-only copy of the application has been unloaded using the
administrator utilities application unloading screen.

File Reformat Limitations.   

Be careful about renaming fields on a record layout.  If you do, all data
in the old fields will be lost as the new field is initialized with the
field's pad character.

You must also be careful about adding new key fields to a record layout,
or changing existing key fields.  If you add a new key to a record
layout, and define that field as a unique key, HP ALLBASE/4GL will not be
able to reformat the file.

Similarly, you cannot change an existing key that permits duplicates to a
key that only allows unique values.

During the data file reformatting process, HP ALLBASE/4GL issues messages
if the reformatting will shorten any fields, or reduce the number of
occurrences of a field defined as having more than one occurrence.  In
these circumstances, HP ALLBASE/4GL issues a message requesting you to
confirm that you want to continue with the file reformatting process.

HP ALLBASE/SQL Table Reformatting.     

HP ALLBASE/4GL does not provide any direct facilities to allow you to
reformat HP ALLBASE/SQL tables.

If you change the specification of a field, or add a new field to the
table record layout, you can use the ISQL UNLOAD/LOAD facilities to
reformat the table.  Refer to the ISQL Reference Manual for more
information.

HP TurboIMAGE/iX Data Set Reformatting.     

HP ALLBASE/4GL does not provide any direct facilities to allow you to
reformat HP TurboIMAGE/iX data sets.

Refer to the HP TurboIMAGE/iX Database Management System Reference Manual 
or the HP TurboIMAGE/iX DBchange/XL User's Guide for more information.

Run-Time Environment Data File Reformatting.     

HP ALLBASE/4GL provides a mechanism for automatically reformatting
existing KSAM data files in the run-time environment.

This mechanism uses the existing structure file associated with each KSAM
data file (these files are indicated by the S suffix), and a
file-structure file that is created during the run-time application
unloading procedure.

When a run-time application is loaded into the target system, HP
ALLBASE/4GL compares the structure for each existing data file, as
defined by its existing structure file, and the format for the incoming
data file as shown in the file-structure file.  If the two formats
differ, HP ALLBASE/4GL reformats the data file.

Under the MPE/iX system, the run-time environment system administrator
must be the creator of the files to be able to reformat them.

The run-time data file reformatting system is described in the HP 
ALLBASE/4GL Developer Administration Manual.

MPE/iX 5.0 Documentation