Date:         Wed, 9 Aug 2000 15:55:32 +0100
Reply-To:     Peter Crawford <peter.crawford@DB.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Peter Crawford <peter.crawford@DB.COM>
Subject:      Antwort: Re: MVS - output to multiple members of a PDS
Comments: To: don_stanley@xtra.co.nz, Fabrizio1@usa.net
Content-type: text/plain; charset=us-ascii

Perhaps the example I posted before reading Don's points, appears to contradict Fabrizio, but filevar is a special feature. By using filevar, only one file handle is open at a time.
When I returned to write to a member that was opened previously (like on a previous data step iteration), the file statement re-opened the member and started writing at the first line (not appending).
Using filevar to specify the target member results in only one member being open for the pds/file statement at a time. If more than one file ref is used, then it might appear to the data step engines that two or more file handles are needed at the same time.
1760  data _null_;
1761     length file $44 ;
1762     retain pds "%sysfunc(pathname(tpds))";
1763     file = pds !! '(A1234567)';
1764     file dum filevar=file ;
1765     put 'in the first member';
1766
1767     file = pds !! '(B1234)';
1768     file dum filevar=file ;
1769     put 'in the next member';
1770
1771     file = pds !! '(C1234)';
1772     file dunce filevar=file ;
1773     put 'in the 3rd member';
1774    stop;
1775  run;

NOTE: The file DUM is:
      Dsname=XTRNCRF.TEST.PDS.TEMP(A1234567),
      Unit=3390,Volume=TSO429,Disp=SHR,Blksize=27998,
      Lrecl=1000,Recfm=VB

NOTE: The file DUM is:
      Dsname=XTRNCRF.TEST.PDS.TEMP(B1234),
      Unit=3390,Volume=TSO429,Disp=SHR,Blksize=27998,
      Lrecl=1000,Recfm=VB

ERROR: OPEN failed for XTRNCRF.TEST.PDS.TEMP.  Multiple members of a single
       cannot be open for output at the same time.
FILE=XTRNCRF.TEST.PDS.TEMP(C1234) PDS=XTRNCRF.TEST.PDS.TEMP _ERROR_=1 _N_=1
NOTE: 1 record was written to the file DUM.
      The minimum record length was 19.
      The maximum record length was 19.
NOTE: 1 record was written to the file DUM.
      The minimum record length was 18.
      The maximum record length was 18.
NOTE: The SAS System stopped processing this step because of errors.
NOTE: The DATA statement used 0.02 CPU seconds and 6402K.

Fabrizio
The more I think about the issue of concurrent access, the more I agree with your statements about writing to multiple members



Datum:         09.08.2000 12:18
An:            SAS-L@listserv.uga.edu




Antwort an:    don_stanley@xtra.co.nz

Betreff:       Re: MVS - output to multiple members of a PDS
Nachrichtentext:


I agree that SAS says it cannot be done and would be interested to know if
someone had successfully done it. I believe Fabrizio is correct in his
assertion and the words "the very same time" are the important ones.  The ISPF
editor appears to allow multiple members to be opened at the same time. In
fact, it only opens the members to write to when you exit or issue a SAVE
command. To do these commands requires the directory of the PDS to be updated.
The directory for all intents and purposes requires an exclusive hold to do an
update, so at the "very same time" no two members can be written.

You can update multiple members as I recall using a separate view for each
member and then setting both views in the same datastep. But don't quote me on
that, I'm thinking back awhile.

Don

F a b r i z i o wrote:

> Mathur, Mukesh [IBM GSA] wrote in message
> <7122E3C522C2D311B9C700508B02DCA3478FFF@NTMSG0099>...
> >Hello MVS people,
> >
> >We have a job that updates multiple members of a PDS in one datastep. This
> >has been running ok on one mainframe, but when we moved it to another
> domain
> >it failed. Error was' Open failed for pds - Multiple members of a single
> PDS
> >cannot be open for output at the same time'.
>
> Cannot imagine MVS would allow multiple members to be written to the
> same PDS at the very same time. Maybe your first site has special
> system software running to handle this type of problem?
>
> It is certainly not a virtue of SAS to facilitate techniques not supported
> by
> your operating system.
>
> HTH? Fabrizio

--
Don Stanley, B.SC, Dip O.R.S, MNZCS     Director, Sysware Consulting Group
                                        Box 634, Wellington, NEW ZEALAND
                                        http://www.sysware.co.nz
EMAIL:: don_stanley@xtra.co.nz

Author:: Beyond the obvious with SAS Screen Control Language.
Author:: Solutions for your GUI Applications Development Using SAS/AF FRAME
Technology

http://www.geocities.com/don_stanley_nz/don_home.htm
Genealogy:: http://www.geocities.com/don_stanley_nz/family.htm
SAS Tips:: http://www.geocities.com/don_stanley_nz/sastips.htm