DFSORT: How to OVERLAY Values Best Example

OVERLAY the field values using DFSORT utility, I have explained with a simple example.

Mainframe how they work.

Overlay Example.

//SYSIN DD * 
* Skip the first three records 
OPTION SKIPREC=3 
* Keep records that meet the specified 
* field-to-field or 
* field-to-constant selection criteria 
INCLUDE COND=(7,5,PD,LE,22,5,PD,OR,
25,3,CH,EQ,C'J69') 
* Add a sequence number to the 
* remaining records. 
INREC OVERLAY=(73:SEQNUM,8,ZD) 
* Sort the records. 
SORT FIELDS=(20,8,ZD,A,11,2,CH,D) 
* Produce one record for each unique
* sort key with totals 
* for the specified summary fields 
SUM FIELDS=(45,4,BI,8,2,PD) 
* Produce output records displaying 
* the sort and sum fields
* intermixed with constants 
* and arithmetic operations. 
OUTREC BUILD=(8C'0',20,8,ZD,
M11,4X,11,2,4C'*', 
45,4,BI,M11,4X,8,2,PD,M11,
((32,6,PD,MUL,-50),ADD,58,3,ZD),
M11,LENGTH=8, 73,8) 
* Produce three output data sets 
* from one pass over the input 
OUTFIL FNAMES=(OUT1,OUT2,OUT3) 
/*

Detailed Explanation for Overlay

Using OVERLAY, you reformat each record by specifying just the items that overlay specific columns.

OVERLAY lets you change specific existing columns without affecting the entire record. In the below example:

OUTREC OVERLAY=(45:45,8,TRAN=LTOU)

Starts from position 45, and length 8, translating lower case to upper case. This example clearly tells how we can use Overlay.

One of the frequently asked interview Question, in IBM, Tech Mahindra, CTS, and Dell. Why means all financial projects using Sort, to sort all reports.

The OVERLAY you can apply in both the INREC and OUTREC formattings.

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Author: Srini

Experienced software developer. Skills in Development, Coding, Testing and Debugging. Good Data analytic skills (Data Warehousing and BI). Also skills in Mainframe.