exp system/password file=a.dmp
imp system/password file=a.dmp fromuser=user1 touser=user2 rows=y indexes=y
exp system/pwd@db_link owner=user1 file=c:\test.dmp log=c:\test.log
imp system/pwd@db_link fromuser=user1 touser=user2 ignore=y file=c:\test.dmp log=c:\imp.log