SORT Card with EQUALS and SORT Card without EQUALS

thunderstorm · New User Joined: 23 Mar 2007 Posts: 35 Location: pune

We have a single input file and an single output file. The file is being sorted on the basis of a key field which is defined as character but can contain numeric values as well.

The mainframe installation's has the default as EQUALS
When I execute the step having EQUALS option and compare the output file with the same step without EQUALS option , I would expect the output files to be same but I have observed that there are differences observed in the ordering of the files with the same key.

Can you let me know why is it happenning ?

Thanks,
Thunder

superk · Posted: Sat Sep 10, 2011 5:56 am

This explains it nicely.

Phrzby Phil · Posted: Sat Sep 10, 2011 6:06 am

When you say "character" you need not say "may also contain numeric values." Digits are characters just like every other symbol represented by a hex code and also those hex codes without display characters. All 256 values can be there.

Also, numeric "value" may be misleading, because " 10" and "010" may evaluate the same numerically, but not as character strings.

Being picky here, but that's the way we need to be.

Phrzby Phil · Posted: Sat Sep 10, 2011 6:10 am

Superk -

How does that explain it. Poster says their default is EQUALS, so whether he says it or not, shouldn't he get the same results?

BTW - My opinion - I think the default should be NOT EQUAL. Our SAS installation has default = EQUALS, and I see novices therefore assume that any sort anywhere will preserve order.

dick scherrer · Posted: Sat Sep 10, 2011 9:31 am

Hello,

Bill Woodger · Posted: Sat Sep 10, 2011 4:55 pm

To me also EQUALS is a strange default. EQUALS necessarily uses more resources. For every sort with unique keys, you'd have to specify NOEQUALS explicitly, or just go with the waste.

Two sorts, one with EQUALS as the default and the other specifying EQUALS, should give you identical output files.

So, let's see the two steps, and their output messages.

dick scherrer · Posted: Sat Sep 10, 2011 9:33 pm

Hello,

Phrzby Phil · Posted: Sun Sep 11, 2011 12:24 am

Bill Woodger · Posted: Sun Sep 11, 2011 2:51 am

Phrzby Phil · Posted: Sun Sep 11, 2011 9:15 am

Yeah Bill - that's good and appreciated. Gotta keep what's important up front. Thanks!

dick scherrer · Posted: Sun Sep 11, 2011 9:28 am

Hi Guys,

Frank Yaeger · Posted: Mon Sep 12, 2011 11:51 pm

For DFSORT, if EQUALS is in effect for both steps (regardless of how EQUALS is set in effect) with the same input, the output will be identical.

If NOEQUALS is in effect for either or both steps, the output may not be identical.

Thunderstorm would have to show us the input, output and JES log for both runs in order for anyone to say anything conclusive about the results vs expectations. Anything else is just guessing.

Phrzby Phil · Posted: Mon Sep 12, 2011 11:55 pm

Of course, but as usual we've enjoyed each others' company awaiting Thunder's return.

thunderstorm · New User Joined: 23 Mar 2007 Posts: 35 Location: pune

Frank,

I have a file which i am sorting on the basis of a character field.
The field starts from 7th field and is 37 bytes long and i am sorting on Ascending sequence.
Here is the portion of data where i am facing issue

Input :
----+----1----+----2----+----3----+----4----+----5-
04072 RR 1
06498 RR 1
08648 RR 1
18447 RR 1
17754 RR 1
15801 RR 1

Output 1
When i submit the SORT job with only this 6 records in the input file and without explicit EQUALS ( SORT FIELDS=(7,37,CH,A)) , I get the output as

04072 RR 1
06498 RR 1
08648 RR 1
18447 RR 1
17754 RR 1
15801 RR 1

Output 2
When I submit the job which has around 2000 records in the input file and with explicit EQUALS specified in the sort card
( SORT FIELDS=(7,37,CH,A),EQUALS)and i look for the order in the output for only the above records I find it to be in this order

04072 RR 1
06498 RR 1
08648 RR 1
15801 RR 1
17754 RR 1
18447 RR 1

The sort order seems to be varying with the number of records in the input file. Can you help me understand why this is happenning. If you need any other details ..please let me know

Thanks,
Thunder

Frank Yaeger · Posted: Tue Sep 13, 2011 5:27 am

As stated previously:

Show us the complete JES log for each run

If you prefer, you can e-mail it to me directly (yaeger@us.ibm.com) and I'll take a look.

dick scherrer · Posted: Tue Sep 13, 2011 8:18 am

Hello,

Phrzby Phil · Posted: Tue Sep 13, 2011 5:48 pm

You have now said or shown that in your file with about 2000 records: the six records you are showing are in fact in the same order as in the file with just those six records.

Frank Yaeger · Posted: Tue Sep 13, 2011 10:59 pm

Again: Thunderstorm would have to show us the input, output and JES log for both runs in order for anyone to say anything conclusive about the results vs expectations. Anything else is just guessing.