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theenigma · Beginner Joined: 09 Jan 2003 Posts: 15 Topics: 6

Is there a simple Way of finding the number of records(without the help of eztrieve or cobol). The Tape file contains anywhere between 6 million and 20 million records.

Sort would do, but, i just need the count, having a sortout or having the sortout dummy'ed would not be a good idea.As it takes the same time(few precious mainframe hrs)

Thanks
Enigma

kolusu · Posted: Wed Feb 12, 2003 6:54 am Post subject:

theenigma,

I don't think there is any simple way to get the total no: of records without reading the entire file.

But if the file has a trailer record with the no: of records in the file , then we can use file-aid's COPYBACK option to read only the last record of the file.

Hope this helps...

cheers

kolusu

Himesh · Posted: Wed Feb 12, 2003 11:05 pm Post subject:

theenigma,

maybe the REXX gurus can help.

The file could be opened using a REXX program in BROWSE mode(it's faster that way), then get the line number of the last line.

regards,
Himesh

theenigma · Beginner Joined: 09 Jan 2003 Posts: 15 Topics: 6

Himesh,

It would not help, REXX cannot open the File just as we cant, as it is a Tape File.

Everyone,

Iam forced to use an Eztrieve Program and it is taking me almost an hour each time.

Folks, cant there be a simpler way Sad

!!!!

Thanks
Enigma

Dibakar · Posted: Fri Feb 14, 2003 4:43 am Post subject:

Assuming the worst case, there are no such methods, can it be done that -

1: Bisection method - Try to read the billionth record. If it is EOF then read half billionth billionth record else read two billionth record and repeat till you have reached the last record. I feel, this would be much faster than reading all.

2: As already suggested - Keep a stat record or file which will just tell the number of records in the tape and gets updated whenever the tape is updated.

Dibakar

theenigma · Beginner Joined: 09 Jan 2003 Posts: 15 Topics: 6

Dibakar,

What you forgot is, Tapes are Sequentail Devices, and you can reach the billionth record only after reading thru the (billion -1) records in front.

That doesnt help, nor does the second method, the tape is already there and i need to do it now. As i said, i already managed with sort, but is very time consuming!!!

anyway, Thanks for ur help
Enigma

DaveyC · Posted: Fri Feb 14, 2003 9:58 am Post subject:

I don't know how accurate it is, but you can get the block count from the label of the tape. You can then calculate the records per block and have an approximate count of the amount of records.

If you have a TMS system like CA-1 you can use the online interface to get this information so you don't have to run a batch job. If I remember correctly, you will need to specify BLP in the label keyword of the JCL. Some sites block this facility with RACF.

Himesh, I can't think of a worse language for counting records than REXX. It's not as powerful as it's reputation.
_________________
Dave Crayford

Himesh · Posted: Tue Feb 18, 2003 4:36 am Post subject:

Dave,

I just took a wild shot.....

Was just interested in knowing
1. If the file could be opened using a REXX program
2. Issue an "M PF8" or "BOT" command
3. Get the line number of the last record.

This sounds easy doesn't it! Laughing

regards,
Himesh

DaveyC · Posted: Tue Feb 18, 2003 6:58 am Post subject:

DaveyC · Posted: Tue Feb 18, 2003 8:14 am Post subject:

AFAIK, you can use DITTO to display tape records in full screen mode. But that would not solve your problem, as you would still have to read every record on the tape to know the number of records. It would be a very silly thing to do.

Anyway, all this counting records is a bit silly. I would just keep a catalog of the file and how many records were written to it.
_________________
Dave Crayford

Ray D · Posted: Wed Feb 19, 2003 12:02 pm Post subject:

I know of no way to get a record count from a tape without reading it and I've been in the business 35 years. What we do at my site is use IDCAMS to repro it to a "DD DUMMY" File. IDCAMS gives you the number of records read.

Frank Yaeger · Posted: Wed Feb 19, 2003 12:35 pm Post subject:

Enigma,

When you say "Sort would do", do you mean you're using a copy to get the count, or a sort to get the count? Copy is much faster than sort, so if you're using a sort, try a copy instead. "Hours" for a copy job doesn't sound right to me. Try this DFSORT/ICETOOL job that just returns the count of the records in TOOLMSG (it does input I/O, but no output I/O):