DFSORT – Now With Extra Magical Ingredients

(Originally posted 2011–04–21.)

Thanks to Scott Drummond for reminding me of last Autumn’s DFSORT Function PTFs – UK90025 and UK90026. They’re mentioned in the preview for z/OS Release 13 so now is not such a bad time to be talking about them. So let me pick out a few highlights:

Translation Between ASCII And EBCDIC, And To And From Hex and Binary

For a long time DFSORT has been able to translate to upper case (TRAN=LTOU), to lower case (TRAN=UTOL) and using a table (TRAN=ALTSEQ).

Now you can convert from ASCII to EBCDIC (TRAN=ATOE) and back (TRAN=ETOA). Translation is performed using TCP/IP’s hardcoded translation table.

Other “utility” translations are added: BIT, UNBIT, HEX and UNHEX. For example TRAN=HEX would translate X’C1F1′ to C’C1F1′ and TRAN=UNBIT would
translate C’1100000111110001′ to X’C1F1′.

Date Field Arithmetic

DFSORT already had some nice functions for handling dates and times. But here are some new things. This isn’t an exhaustive list:

  • You can add years to a date field – with ADDYEARS.
  • You can subtract months from a date field – with SUBMONS.
  • You can calculate the difference between two dates – with DATEDIFF.
  • You can calculate the next Tuesday for a date field – with NEXTDTUE.
  • You can calculate the previous Wednesday for a date field – with PREVDWED.
  • You can calculate the last day of the quarter – with LASTDAYQ.

JCL Symbols In Control Statements

You can now construct Symbols incorporating JCL PROC or SET symbols. These can be used in DFSORT and ICETOOL control statements, just like other symbols. You specify this by coding JPn“&MYSYM” in the PARM parameter of the EXEC statement. (In fact there need be no JCL symbol in this so you could pass in other strings this way and an expected use is for JPn to contain a mixture of JCL Symbols and fixed text.) n can be any one of 0 through to 9.

This support is in addition to the ability to use System Symbols (introduced with UK90013).

Microseconds In Timestamps

You can use the new DATE5 keyword to create a timestamp constant at run-time in the form ‘yyyy-mm-dd-h.mm.ss.nnnnnn’. DB2 folks might recognise this as the timestamp format for DB2 Unload and DSNTIAUL. You can use this for things like comparisons.

Chunking And Stitching Together Records

You can use the new ICETOOL RESIZE operator to:

  • Split records into fixed-sized output records. For example, take a RECFM=FB, LRECL=500 file and create a RECFM=FB, LRECL=100 file – creating 5 new output records from each input record.
  • Join together fixed-sized input records. For example, take a RECFM=FB, LRECL=100 file and create a RECFM=FB, LRECL=500 file – in effect reversing the above by joining 5 input records together to make an output record.

In each case you can see there could be problems with partial output records. DFSORT “does the right thing” using blanks.

Begin Group When Key Changes

I mentioned WHEN=GROUP here, in particular BEGIN=. With BEGIN= you get a new group when the condition you specify is satisfied. Now, with KEYBEGIN= you get a new group when the value in a particular field changes. For example:

SORT FIELDS=(1,12,CH,A,13,8,CH,D)

sticks a group number (3 characters wide) on the end of each record. The group number is incremented when there’s a new value in the 12-byte field that begins in position 1.

There are lots of other (in my opinion) smaller enhancements in this PTF.

If you want to know whether the appropriate PTF is on look for the following message in a DFSORT run:


If you see an “H” then you’re all set.

And you can read about these enhancements in more detail in User Guide for DFSORT PTFs UK90025 and UK90026 (SORTUGPH).

Published by Martin Packer

I'm a mainframe performance guy and have been for the past 35 years. But I play with lots of other technologies as well.

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