IBM Natural Interview Preparation Guide

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Normally in JCLs calling natural program, data is passed
using some control cards. In the natural program, the data
is received in the same order using INPUT statement similar
to STACK processing.

Data definition in Natural is done using following:

DEFINE DATA
1 #VARIABLE1 (A10) /* Alphabetic variable of length 10
..
..
END-DEFINE

ESCAPE TOP indicates that processing is to continue at the
top of the processing loop. This starts the next repetition
of the processing loop.


ESCAPE BOTTOM indicates that processing is to continue with
the first statement following the processing loop. The loop
is terminated and loop-end processing (final BREAK and END
DATA) is executed for all loops being terminated.

Whereas if you specify the keyword IMMEDIATE, no loop-end
processing will be performed(i.e.,final BREAK and END DATA
is not executed for all loops being terminated).

In older version of ADABAS the limit used to be 32 files.
So now it will be eitehr the same or more.

If you wish to position the cursor to a specified field,
you can use the MARK option,
eg.
INPUT
MARK *#MAP.#ACTION
USING MAP 'IVCLNTM1'

and and to position to a
particular position within a specified field, you use the
MARK POSITION option.


DEFINE DATA LOCAL
1 #A (A10)
1 #B (N4)
1 #C (N4)
END-DEFINE
*
INPUT (AD=M) #A #B #C
IF #A = ’ ’
COMPUTE #B = #B + #C
RESET #C
REINPUT FULL ’Enter a value’ MARK POSITION 5 IN *#A
END-IF
END

Number of occurances in MU and PE can be found by c*field
name.

If Adabas file having MU field 'switch' and has 5 values.
then in module you can find it by C*switch. this will have
value 5.

Both used to read sequentila file.
Read work file 1:

1. is a processing loop strating like:
Read work file 1 file1
---
--
--
end- work.
Here ---> file 1 is file name here and 1 is arbitary file
number which is translated into dataset names CMwk01 in jcl.

read work file once:
1. Reads only one reacord is to be read.
2. there is no processing loop
eg. Read work file once

Read(1) file1 in physical sequence:
1. Used to raed adabas file.
2. here (1 ) represents the number of record to be read
its a processing loop eg

Read(1) file1 in physical sequence
--
---
---
end-read

read work file :
1. Used to read flate file.
2. Once option is used to read only one record
3. its not a processing loop

Hitogram retruns the one line output for each key value
from the inverted list. for histogram ADABAS does not have
access to data storage,therefore we can not do any update
add or delete using histogram.

An external subroutine can access the global data area used
by the invoking object(Program, Subprogram)
Moreover, parameters can be passed with the PERFORM
statement from the invoking object to the external
subroutine. These parameters must be defined either in the
DEFINE DATA PARAMETER statement of the subroutine, or in a
parameter data area used by the subroutine. Programs,
Subprograms and Subroutines Programming Guide
In addition, an external subroutine can have its local data
area, in which the fields that are to be used only within
the subroutine are defined.
However, an external subroutine cannot have its own global
data area.

I think directly this conversion is not possible as packed
decimal is used for numeric value fields only.
Since it is p(8) so the numeric value field size should be
15 or 16 as [8 can be either (n+1)/2 i.e. (15+1)/2 or ( n/2)
i.e. 16/2].
So we can say (n15 or 16) will be (P8).
Alternatively (A16 or 15)