Example of Accessing the FCD

The following program turns on key compression in a file by setting the appropriate bits in the file's Key Definition Block.

$set fcdreg
 select masterfile
     assign to ...
     organization is indexed
     record key is rec-key
     alternate key is m-alt-key-1 with duplicates
     alternate key is m-alt-key-2
     alternate key is m-alt-key-3 with duplicates.

 select indexfile
     assign to ...
     organization is indexed
     record key is rec-key
     alternate key is t-alt-key-1 with duplicates.
 ...
 working-storage section.
 ...
 linkage section.
 01 key-def-block.
     03 filler     pic x(6).
     03 key-count    pic 9(4) comp-x.
     03 filler     pic x(6).
     03 key-def occurs 1 to 4 times depending on key-count.
         05 filler    pic x(5).
         05 key-compression pic 9(2) comp-x.
         05 filler    pic x(10).
   ...
 procedure division.
     set address of key-def-block to address of fh--keydef of masterfile
     move 6 to key-compression (1)
     move 7 to key-compression (2)
     move 6 to key-compression (3)
     move 7 to key-compression (4)
     open I-O masterfile
     ...
     set address of key-def-block to address of fh--keydef of indexfile
     move 4 to key-compression (1)
     move 1 to key-compression (2)
     open input indexfile