Joined: 06 Jun 2008 Posts: 8117 Location: East Dubuque, Illinois, USA
What do you not understand? You are accessing the same file multiple times in different ways simultaneously. Nothing different than accessing two different files at the same time. Remember, each file you declare in COBOL has its own record pointer and buffers so FILE1-SEQ and FILE1-DYN are accessing the file independently of one another.
Note that if you update the file you may start experiencing problems.