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arvibala · Beginner Joined: 12 Feb 2008 Posts: 142 Topics: 67

Hi,

Our VSAM, say VSAM1 has a key length of 15. We have defined an alternate Index too of length 7. Assuming we will have 1000 combinations of the Key field for an Alternate Index, we have the Max record size defined as 15007.

ie.,

15*1000+7

I guess the Max record size allowed is 32600 ( IBM reference), in that case I can have only

(32600-7)/15 = 2172 combinations only.

What should I do if the combinations exceed 2172? Any solution so that I do this at the Job level and not touch the code?

Thanks
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Arvind
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kolusu · Posted: Mon Apr 06, 2009 5:24 pm Post subject:

arvibala,

You got the math wrong. AFAIK the alternate index's key record can point to a maximum of 32767 records with nonunique keys. Also you can have have upto 253 AI's.

why is this topic in database?

Kolusu

warp5 · Posted: Tue Apr 07, 2009 1:07 am Post subject:

I question the use of an alternate key in this case. Alternate keys cause an additional overhead for each added record. In my opinion you would be better off to read your vsam dataset and sort it according to your alternate key and then process it. Another alternative would be to define a more unique alternate index.

arvibala · Beginner Joined: 12 Feb 2008 Posts: 142 Topics: 67

kolusu,

32767 is the record Size and if the Key is 15 Char in length and Alternate index is 7 char in length, we can have only (32767-7)/15, non-unique keys for an alternate index. I have the screen shot here.

Terry_Heinze · Posted: Tue Apr 07, 2009 12:36 pm Post subject:

warp5 · Posted: Wed Apr 08, 2009 1:04 am Post subject:

Maybe you should post what you want to do and how many records we are talking about. Often you are better off using sort and other utilities (fast and efficient) instead of trying to bend things to work.