Can someone tell me how MVS FOCUS handles header and trailer records (like the heading) for VSAM files? Does it have some way of disposing of them?

Typically HEADER and TRAILER records in a VSAM file are treated as "RECTYPES". We allow them to be described, as often there is information in the header/trailer that the customer needs on the report. Now, the problem becomes if you don't have a natural RECTYPE. For instance, let's say that the HEADER record has HDR in the first 3 characters, and FOOTER has FTR in the same 3 characters. If it is not a HEADER or FOOTER, then the first 9 characters are social security number. In that case, we will use a rectype indicating that the important record has 001 thru 999 in characters 1-3, and that anything else should be ignored (I'm also for this indicating that the 9 chracter SSN is also the VSAM KEY.

FILE=vsam,SUFFIX=VSAM
SEGNAME=DUMMY,SEGTYPE=S0
FIELD= , , A1,A1,$
SEGNAME=MOSTREC,SEGTYPE=S0,PARENT=DUMMY
GROUP=SSN,ALIAS=KEY,A3,A3,$
FIELD=RECTYPE,,A3,A3,ACCEPT='001' TO '999',$
FIELD=FILLER,,A6,A6,$
... Describe the rest of the fields ...
SEGNAME=HDR,PARENT=DUMMY,SEGTYPE=S0
FIELD=RECTYPE,,A3,A3,ACCEPT='HDR',$
SEGNAME=HDRM,OCCURS=VARIABLE,PARENT=HDR
FIELD=WHOCARES,,A1,A1,$

Note if you truly do not care about the header (or trailer) information, you can just leave out those segments.s

Thank you! That was very helpful.

Stan

Noreen

What if there was an external file of ssn's that needed to be joined to the file described by your master? Would a vsam key be used in the join?

Thanks

Sorry, I was on vacation last week. Sure, create a SUFFIX=FIX (or whatever) file with the SSN's that you want, and then JOIN SSN IN FLATFILE TO SSN IN VSAMFILE AS AJ
You can JOIN using the VSAM key, the Left-most entrie(s) in the VSAM key, or the same using an alternate index that you set up using IDCAMS. Since you mention SSN, The RECTYPE will also be implied.

Thanks Noreen. I have no way to really test this. I have built many Vsam masters in the past but the files I went after had real rectyps. I was just not sure that a Vsam key described in the master that way (with a dummy segment) would work in a join.

Thanks again.