The ORGANIZATION clause specifies the logical structure of the file. The file organization is established at the time the file is created and cannot subsequently be changed.
For database files, the ORGANIZATION clause indicates the current program usage of the file in the program. Therefore, the same database file can use SEQUENTIAL, RELATIVE, or INDEXED (assuming a keyed sequence access path exists) in the ORGANIZATION clause. This is true regardless of what is specified in other programs that use this file.
A keyed sequence access path is always created when a key is specified in the DDS that was used as input to the Create Physical File (CRTPF) or the Create Logical File (CRTLF) CL command.