Defining duplicate keys in vsam file

vamskrish · New User Joined: 31 Jan 2007 Posts: 27 Location: virginia

hi,
can i have a key with duplicate values. if yes then how can i define it.
also...say following is my data structure...

01 data-rec.
05 A pic s9(9).
05 B pic s9(9).
05 C pic x(2).
05 D pic x9(3).
05 E pic x9(1).

now, my questions?
1. can i define key as combination of fields from A thru E. if yes how.
2. can i again define each of the fields from A thru E as an alternate key, even after defining the combination as primary.
3. can i just define alternate keys without defining primary keys.(i dont think so)

dick scherrer · Posted: Thu Feb 01, 2007 1:25 am

Hello,

1 - yes - VSAM doesn't use field name, just length/displacement in the definition.

2 - yes

3 - no, not to my knowledge. . .

Look up DEFINE ALTERNATEINDEX in the IDCAMS manual for your secondary keys.

vamskrish · New User Joined: 31 Jan 2007 Posts: 27 Location: virginia

for question 2, how do i mention that in the program in input-output section. record key is ------ ?

William Thompson · Posted: Thu Feb 01, 2007 4:21 am

So many questions.

#3, You can have alternate keys without defining a primary key.

As far as #1 go, like Dick hinted at, not as any "combination of fields from A thru E", they must be contiguous and in order.

#2a, You aren't really going to make read the manual for you, are you? IIRC, inside the COBOL program, the view of keyed VSAM dataset is just that, a keyed VSAM dataset. What you point to with your DD statement is all the program sees and the fact that it points to an AIX means nothing, AMS uses "smoke and mirrors" to provide access as needed.