The RELEASE statement transfers records to the initial phase of a sort
  operation.

  Format -

   RELEASE rec [ FROM src-area ]

1  –  rec

  is the name of a logical record in a sort-merge file description (SD)
  entry.  It can be qualified.

2  –  src-area

  is the identifier of the data item that contains the data. If src-area
  is a function-identifier, it must reference an alphanumeric function.