QSAM concatenation where the first DD is DUMMY?
What happens when you have a QSAM concatenation where the first DD is overridden to DUMMY? I have a production PROC with a QSAM input DD that concatenates four datasets. In one job the initial DD is overridden to DUMMY but the others are not overridden at all. The second DD in the concatenation is a valid file, but it was not read at all. It seems like overriding the first DD to DUMMY made the entire concatenation DUMMY. Is that how it works? Example: In MYPROC: //PSTEP1 EXEC PGM=MYPGM //INPUT DD DISP=SHR,DSN=FILE1 // DD DISP=SHR,DSN=FILE2 // DD DISP=SHR,DSN=FILE3 // DD DISP=SHR,DSN=FILE4 Job: //STEP1 EXEC MYPROC //PSTEP1.INPUT DD DUMMY Do I need to change the job override to something like this: //PSTEP1.INPUT DD DUMMY // DD // DD // DD Or do I have to do it like this: //PSTEP1.INPUT DD DSN=FILE2 // DD DUMMY // DD // DD TIA for curing my ignorance. I thought I knew this stuff but I guess that I don't know it as well as I thought I did. Peter -- This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: QSAM concatenation where the first DD is DUMMY?
On 3/7/2011 8:40 AM, Farley, Peter x23353 wrote: What happens when you have a QSAM concatenation where the first DD is overridden to DUMMY? I have a production PROC with a QSAM input DD that concatenates four datasets. In one job the initial DD is overridden to DUMMY but the others are not overridden at all. The second DD in the concatenation is a valid file, but it was not read at all. It seems like overriding the first DD to DUMMY made the entire concatenation DUMMY. Is that how it works? Yes. More fully, if a DD statement in a concatenation is specified as DUMMY, all subsequent DD statements in the concatenation are treated as DUMMY Example: In MYPROC: //PSTEP1 EXEC PGM=MYPGM //INPUT DD DISP=SHR,DSN=FILE1 // DD DISP=SHR,DSN=FILE2 // DD DISP=SHR,DSN=FILE3 // DD DISP=SHR,DSN=FILE4 Job: //STEP1 EXEC MYPROC //PSTEP1.INPUT DD DUMMY Do I need to change the job override to something like this: //PSTEP1.INPUT DD DUMMY // DD // DD // DD Or do I have to do it like this: //PSTEP1.INPUT DD DSN=FILE2 // DD DUMMY // DD // DD TIA for curing my ignorance. I thought I knew this stuff but I guess that I don't know it as well as I thought I did. Peter Well, you don't explicitly state what you are trying to accomplish, but you seem to imply you want the first data set to be skipped and the others to be read. If that's your objective, you would need to code something like: //PSTEP1.INPUT DD DSN=FILE2 // DD DSN=FILE3 // DD DSN=FILE4 // DD DUMMY -- Kind regards, -Steve Comstock The Trainer's Friend, Inc. 303-393-8716 http://www.trainersfriend.com * To get a good Return on your Investment, first make an investment! + Training your people is an excellent investment * Try our new tool for calculating your Return On Investment for training dollars at http://www.trainersfriend.com/ROI/roi.html -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: QSAM concatenation where the first DD is DUMMY?
Thanks Steve. Even old dogs have old tricks to (re)learn, it seems. Peter > -Original Message- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On > Behalf Of Steve Comstock > Sent: Monday, March 07, 2011 10:58 AM > To: IBM-MAIN@bama.ua.edu > Subject: Re: QSAM concatenation where the first DD is DUMMY? > Well, you don't explicitly state what you are trying > to accomplish, but you seem to imply you want the > first data set to be skipped and the others to be > read. If that's your objective, you would need to > code something like: > > //PSTEP1.INPUT DD DSN=FILE2 > // DD DSN=FILE3 > // DD DSN=FILE4 > // DD DUMMY -- This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: QSAM concatenation where the first DD is DUMMY?
Would the effect be the same with DSN=NULLFILE ? I wish I could test; but, I do not have access to a z system these days. The manuals seem to convey NULLFILE and DUMMY do not differ. Of course, one can actually allocate an empty dataset in ISPF 3.2 and then provide this name in the override. ;-) N On Mon, Mar 7, 2011 at 10:42 PM, Farley, Peter x23353 < peter.far...@broadridge.com> wrote: > Thanks Steve. Even old dogs have old tricks to (re)learn, it seems. > > Peter > > > -Original Message- > > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On > > Behalf Of Steve Comstock > > Sent: Monday, March 07, 2011 10:58 AM > > To: IBM-MAIN@bama.ua.edu > > Subject: Re: QSAM concatenation where the first DD is DUMMY? > > > Well, you don't explicitly state what you are trying > > to accomplish, but you seem to imply you want the > > first data set to be skipped and the others to be > > read. If that's your objective, you would need to > > code something like: > > > > //PSTEP1.INPUT DD DSN=FILE2 > > // DD DSN=FILE3 > > // DD DSN=FILE4 > > // DD DUMMY > -- > > This message and any attachments are intended only for the use of the > addressee and > may contain information that is privileged and confidential. If the reader > of the > message is not the intended recipient or an authorized representative of > the > intended recipient, you are hereby notified that any dissemination of this > communication is strictly prohibited. If you have received this > communication in > error, please notify us immediately by e-mail and delete the message and > any > attachments from your system. > > > -- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html > -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: QSAM concatenation where the first DD is DUMMY?
On 3/7/2011 10:36 PM, ನಾಗೇಶ್ ಸುಬ್ರಹ್ಮಣ್ಯ (Nagesh S) wrote: Would the effect be the same with DSN=NULLFILE ? Yes. I wish I could test; but, I do not have access to a z system these days. The manuals seem to convey NULLFILE and DUMMY do not differ. Of course, one can actually allocate an empty dataset in ISPF 3.2 and then provide this name in the override. ;-) Well, you can also allocate an empty dataset in a prior job step, no need to use ISPF. But, unless you are using SMS for this allocation, the file will not have an end of data indicator, so in the step where you try to reference this empty file for input, it will likely fail with an abend. So, it's a little more complicated. Of course you could create an empty file, edit it, including deleting all the lines, then exit. Then use that file in multiple jobs that use input files with the same DCB attributes. N On Mon, Mar 7, 2011 at 10:42 PM, Farley, Peter x23353< peter.far...@broadridge.com> wrote: Thanks Steve. Even old dogs have old tricks to (re)learn, it seems. Peter -Original Message- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On Behalf Of Steve Comstock Sent: Monday, March 07, 2011 10:58 AM To: IBM-MAIN@bama.ua.edu Subject: Re: QSAM concatenation where the first DD is DUMMY? Well, you don't explicitly state what you are trying to accomplish, but you seem to imply you want the first data set to be skipped and the others to be read. If that's your objective, you would need to code something like: //PSTEP1.INPUT DD DSN=FILE2 // DD DSN=FILE3 // DD DSN=FILE4 // DD DUMMY -- Kind regards, -Steve Comstock The Trainer's Friend, Inc. 303-393-8716 http://www.trainersfriend.com * To get a good Return on your Investment, first make an investment! + Training your people is an excellent investment * Try our new tool for calculating your Return On Investment for training dollars at http://www.trainersfriend.com/ROI/roi.html -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: QSAM concatenation where the first DD is DUMMY?
On 3/8/2011 12:36 AM, ನಾಗೇಶ್ ಸುಬ್ರಹ್ಮಣ್ಯ (Nagesh S) wrote: Would the effect be the same with DSN=NULLFILE ? I wish I could test; but, I do not have access to a z system these days. The manuals seem to convey NULLFILE and DUMMY do not differ. Under normal use, there is no practical difference between DD DUMMY and DSN=NULLFILE. DUMMY will show in the TIOT with a zero UCB address, whereas NULLFILE may be pointed to a specific volume, and be supplied with many JFCB parameters (DCB, etc.) that could be used by a programmer to confuse the users Gerhard Postpischil Bradford, VT -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: QSAM concatenation where the first DD is DUMMY?
You could maybe set up a single empty dataset, say, SYS1.NULLFILE or SYS1.DUMMY, that could be used by any job, and refer its DCB to the original dataset that you are nullifying. For example: // DD DSN=ORIGINAL.FILE,DISP=SHR becomes // DD DSN=SYS1.NULLFILE,DCB=ORIGINAL.FILE,DISP=SHR so you just have to insert "SYS1.NULLFILE,DCB=" after "DSN=". > Date: Tue, 8 Mar 2011 06:42:20 -0700 > From: st...@trainersfriend.com > Subject: Re: QSAM concatenation where the first DD is DUMMY? > To: IBM-MAIN@bama.ua.edu > > On 3/7/2011 10:36 PM, ನಾಗೇಶ್ ಸುಬ್ರಹ್ಮಣ್ಯ (Nagesh S) wrote: > > Would the effect be the same with DSN=NULLFILE ? > > Yes. > > I wish I could test; but, I > > do not have access to a z system these days. The manuals seem to convey > > NULLFILE and DUMMY do not differ. > > > > Of course, one can actually allocate an empty dataset in ISPF 3.2 and then > > provide this name in the override. ;-) > > Well, you can also allocate an empty dataset in a prior > job step, no need to use ISPF. But, unless you are using > SMS for this allocation, the file will not have an end > of data indicator, so in the step where you try to > reference this empty file for input, it will likely fail > with an abend. > > So, it's a little more complicated. Of course you could > create an empty file, edit it, including deleting all > the lines, then exit. Then use that file in multiple > jobs that use input files with the same DCB attributes. > > > > > > -- > > Kind regards, > > -Steve Comstock > The Trainer's Friend, Inc.
Re: QSAM concatenation where the first DD is DUMMY?
Well, what if I code this - //DDO1 DD DSN=FILE01,DISP=SHR // DD DUMMY // DD DSN=FILE03,DISP=SHR Does the whole thing get dummied out like before? Thank you very much, Quasar chunawalla Sent on my BlackBerry® from Vodafone -Original Message- From: J R Sender: IBM Mainframe Discussion List Date: Tue, 8 Mar 2011 09:35:38 To: Reply-To: IBM Mainframe Discussion List Subject: Re: QSAM concatenation where the first DD is DUMMY? You could maybe set up a single empty dataset, say, SYS1.NULLFILE or SYS1.DUMMY, that could be used by any job, and refer its DCB to the original dataset that you are nullifying. For example: // DD DSN=ORIGINAL.FILE,DISP=SHR becomes // DD DSN=SYS1.NULLFILE,DCB=ORIGINAL.FILE,DISP=SHR so you just have to insert "SYS1.NULLFILE,DCB=" after "DSN=". > Date: Tue, 8 Mar 2011 06:42:20 -0700 > From: st...@trainersfriend.com > Subject: Re: QSAM concatenation where the first DD is DUMMY? > To: IBM-MAIN@bama.ua.edu > > On 3/7/2011 10:36 PM, ನಾಗೇಶ್ ಸುಬ್ರಹ್ಮಣ್ಯ (Nagesh S) wrote: > > Would the effect be the same with DSN=NULLFILE ? > > Yes. > > I wish I could test; but, I > > do not have access to a z system these days. The manuals seem to convey > > NULLFILE and DUMMY do not differ. > > > > Of course, one can actually allocate an empty dataset in ISPF 3.2 and then > > provide this name in the override. ;-) > > Well, you can also allocate an empty dataset in a prior > job step, no need to use ISPF. But, unless you are using > SMS for this allocation, the file will not have an end > of data indicator, so in the step where you try to > reference this empty file for input, it will likely fail > with an abend. > > So, it's a little more complicated. Of course you could > create an empty file, edit it, including deleting all > the lines, then exit. Then use that file in multiple > jobs that use input files with the same DCB attributes. > > > > > > -- > > Kind regards, > > -Steve Comstock > The Trainer's Friend, Inc. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: QSAM concatenation where the first DD is DUMMY?
You will read FILE01. The DUMMY forces EOF at that point. Christopher Y. Blaicher Senior Software Developer Austin Development Lab phone: 512.340.6154 mobile: 512.627.3803 fax: 512.340.6647 10431 Morado Circle Austin, TX 78759 -Original Message- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On Behalf Of Quasar Chunawalla Sent: Tuesday, March 08, 2011 8:45 AM To: IBM-MAIN@bama.ua.edu Subject: Re: QSAM concatenation where the first DD is DUMMY? Well, what if I code this - //DDO1 DD DSN=FILE01,DISP=SHR // DD DUMMY // DD DSN=FILE03,DISP=SHR Does the whole thing get dummied out like before? Thank you very much, Quasar chunawalla Sent on my BlackBerry® from Vodafone -Original Message- From: J R Sender: IBM Mainframe Discussion List Date: Tue, 8 Mar 2011 09:35:38 To: Reply-To: IBM Mainframe Discussion List Subject: Re: QSAM concatenation where the first DD is DUMMY? You could maybe set up a single empty dataset, say, SYS1.NULLFILE or SYS1.DUMMY, that could be used by any job, and refer its DCB to the original dataset that you are nullifying. For example: // DD DSN=ORIGINAL.FILE,DISP=SHR becomes // DD DSN=SYS1.NULLFILE,DCB=ORIGINAL.FILE,DISP=SHR so you just have to insert "SYS1.NULLFILE,DCB=" after "DSN=". > Date: Tue, 8 Mar 2011 06:42:20 -0700 > From: st...@trainersfriend.com > Subject: Re: QSAM concatenation where the first DD is DUMMY? > To: IBM-MAIN@bama.ua.edu > > On 3/7/2011 10:36 PM, ನಾಗೇಶ್ ಸುಬ್ರಹ್ಮಣ್ಯ (Nagesh S) wrote: > > Would the effect be the same with DSN=NULLFILE ? > > Yes. > > I wish I could test; but, I > > do not have access to a z system these days. The manuals seem to convey > > NULLFILE and DUMMY do not differ. > > > > Of course, one can actually allocate an empty dataset in ISPF 3.2 and then > > provide this name in the override. ;-) > > Well, you can also allocate an empty dataset in a prior > job step, no need to use ISPF. But, unless you are using > SMS for this allocation, the file will not have an end > of data indicator, so in the step where you try to > reference this empty file for input, it will likely fail > with an abend. > > So, it's a little more complicated. Of course you could > create an empty file, edit it, including deleting all > the lines, then exit. Then use that file in multiple > jobs that use input files with the same DCB attributes. > > > > > > -- > > Kind regards, > > -Steve Comstock > The Trainer's Friend, Inc. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
