1. What is adabas?

Adabas is a adaptable database .Natural can be accessed
from adabas. Natural Adabas is supported onmainframe
platform available on windows,unix and open vms
syastems.adabas mainly includess concepts like read ,find
get statement (all the looping statements)

2. How will you the specification of database file?

If you want to know the secification of file in ADABAS such
as file's record length, structure and decleration,
inverted list etc., you have to look the FDT(File
defination Table) through ADAREP option.

3. Suppose If i have updated few fields of Adabas file using UPDATE command, and after that i used display to see that field get updated or not. If in Display it showing nothing or record did not get updated then what can be the possible reasons?

The find instruction may b used to display such that we
applied find command to get the records corresponding to
our search entry and after that record might me updated.So
the updated inverted list will be formed but the ISN list
in the working storage section will not be updated giving
the same records prior to updation.

4. What is the significance of DBID used in Adabs?

DBID stands for database ID, in a Adabas server environment
you can have multiple data base running. DBID represents
unique ID of the database. Each file in Adabas has its DBID
and FNR.

5. What is an Associator in ADABAS?

Associator is one of the datasets of the adabas.
It contains -
Number of adabas files which have been allocated in data
storage.
The physical location of the extents of the file in the data
storage.
Address converter, Inverted list, FDT.

6. How to initialize a variable which is a constant in a LDA. Suppose I want to declare a variable #a N1(1:7) having constant values as 1,2,3,4,5,6, and 7 for respective occurance then how can we do that?

In data area editor screen, define the variable #a with
Format "N" and length 1. Then edit this variable/ field by
typing in a ".e" just before the level number of this
variable. This will take you the "Extended Field Definition
Editing screen". Type the code as "A" for Array index
definition. On the "Index definition" screen, declare your
index as 1:7 press enter and exit the screens until you are
back onto the data area editor screen.Now again type in
a ".e" to edit the same field/ variable and type code "S"
for defining the single initial values. On this initial
value screen, change the "Define as Constant" field value
from "N" (No) to "Y" (yes)and just below it define constant
values against each index value ranging from 1 to 7.

7. What is the difference between Null compression and default compression?

The default compression type for ADABAS is 'Normal'
compression. This compresses the data by removing trailing
spaces from alphanumeric fields, removing leading zeros and
packing numeric fields, and leaving packed fields as is.

Null Suppression is a type of compression. The field must
be designated with 'NU' for this compression to occur.
Null suppressed fields that are blank or zero only take up
one byte insted of two. If there are multiple empty fields
together they can be compressed into a one byte empty field
count.