Some file operations exclusively allocate the file for the length of the operation. When the file is allocated exclusively, any program trying to open the file has to wait until it is released. However, you can set a wait time for the file to become available using the WAITFILE parameter .
You can control the amount of time a program waits for the file to become available by specifying a wait time on the WAITFILE parameter of the create and change file commands and the override database file command. If you do not specifically request a wait time, the system defaults the file wait time to zero seconds.
A file is exclusively allocated when an operation that changes its attributes is run. These operations (such as move, rename, grant or revoke authority, change owner, or delete) cannot be run at the same time with any other operation on the same file or on members of that file. Other file operations (such as display, open, dump, or check object) only use the file definition, and thus lock the file less exclusively. They can run at the same time with each other and with input/output operations on a member.