MVSFORUMS.com

psmadhusudhan · Beginner Joined: 28 Nov 2006 Posts: 143 Topics: 48

I have one program which reads data from DB2 table for particular date through cursor and loads every records into VSAM file and prints every record into a sysout report. At some days there will be huge data fetched through cursor(around 20L records), because of this program is running for longer duration around 2 hours.

I would like to know if we keep an unload step before the program to unload the records fetched through cursor and in the program load the VSAM file using above unloaded file; will this improve the performance.

Or please suggest any good solution which will increase performance.
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Thanks
Madhu Sudhan

kolusu · Posted: Fri Dec 09, 2011 11:19 am Post subject:

psmadhusudhan,

Why are you printing every record in the sysout? You are filling up the spool with your displays. An unload and simple REPRO would be an easy solution and also have a good performance.

Kolusu

dbzTHEdinosauer · Posted: Fri Dec 09, 2011 1:46 pm Post subject:

and instead of sysout,
you have the intermediate file between the unload and repro
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Dick Brenholtz
American living in Varel, Germany

Anuj Dhawan · Posted: Mon Dec 12, 2011 4:54 am Post subject:

If generating the SYSOUT report is necessary, may be, use an internal COBOL-table and instead of priting one by one record - prtint the table at one go - it might save some I/Os possibly... .
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Anuj

psmadhusudhan · Beginner Joined: 28 Nov 2006 Posts: 143 Topics: 48

Thanks all for your suggestions.
I need intermediate file because their are some checks need to be done and some formatting before loading into VSAM file.
Anyways I will try to do the checks through SORT. I wll work on the solution and let you know.
_________________
Thanks
Madhu Sudhan

papadi · Supermod Joined: 20 Oct 2009 Posts: 594 Topics: 1

Until the complete requirement is understood, there cannot be really useful suggestions on the implementation.

If you keep adding "things" that must be part of the process, earlier suggestions will probably be negated.

Once you explain "everyting" than must be accomplished, better suggestions can be offered. You are trying to get help with performance, but have not provided anything consistent for us to use to help you.
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All the best,

di

Anuj Dhawan · Posted: Tue Dec 13, 2011 4:09 am Post subject:

Reading your (OP) latest post and everything what papadi says make sense - it's hard to hit a moving target!
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Regards,
Anuj

psmadhusudhan · Beginner Joined: 28 Nov 2006 Posts: 143 Topics: 48

I have to do below processing with the unload file.

For every record of unload file read VSAM file with unload key
> If record is already present in VSAM I need to update the VSAM record with adding some non key fields of VSAM and Unload file.
> If no record found in VSAM file then Write the record in VSAM file.

There might be duplicates in Unload file on Key combination.

Please suggest if it is possible to do above logic in Easytrieve.
I have started writing Easytrieve program through matching technique, but couldn't get the logic of rewriting the VSAM record if it gets matched.
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Thanks
Madhu Sudhan

papadi · Supermod Joined: 20 Oct 2009 Posts: 594 Topics: 1

How/why did we make the leap to Easytrieve . . . Confused

Yes, this can be done in Easytrieve as well as COBOL (or lots of other languages).

In any language, i believe you have already shown the process.

Unload the data.
Read the data handling duplicates as need be.
Update existing records and Write new records into the file.
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All the best,

di

psmadhusudhan · Beginner Joined: 28 Nov 2006 Posts: 143 Topics: 48

Hi can we do matching between sequential file and VSAM file; update VSAM file if matched and write into VSAM file if not matched
_________________
Thanks
Madhu Sudhan

papadi · Supermod Joined: 20 Oct 2009 Posts: 594 Topics: 1

Yes, why might there be a doubt?

I do not believe i understand the problem/question Embarassed

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All the best,

di

psmadhusudhan · Beginner Joined: 28 Nov 2006 Posts: 143 Topics: 48

Hi All,

I tried matching sequential file and VSAM ; if matched tried updating VSAM but I am getting below error

papadi · Supermod Joined: 20 Oct 2009 Posts: 594 Topics: 1

Does this fail on the first attempt to write or has the job run for some time before this error.

What happpens where there is a different number of records in each file?

Why try to use MATCHED when you could read the sequential file and then difrectly read the vsam file by the key from the sequential record?
_________________
All the best,

di

kolusu · Posted: Mon Dec 19, 2011 12:41 pm Post subject:

psmadhusudhan,

By now you should have known that you can't IF matched logic on a VSAM for rewriting.

Here is an untested program written purely based on my memory. So use it with caution. Use code tags so that the spacing is retained and code is readable.