Abstract: A task, activated on one computer system is delegated to heterogeneous computer systems, the input of the task, residing on a shared device, read for that task through a function using heterogeneous read and the output of the task written by a function using heterogeneous write, back to the shared device.

Abstract: The log file maintained by a DBMS is used, possibly in conjunction with hardware that listens to the communication between a computer and the storage controller to create cache buffers and a locking mechanism that enable applications running on one computer system to consistently access the data maintained and updated by a different computer.

Abstract: An index of a relational database or an indexed sequential file is used in a method that does not depend on the implicit or explicit definition of ranges of a key formed as a binary number from concatenation of columns of a Table in the database. As long as not all relevant ranges of the key have been exhausted, the beginning of a next range is found and row identifiers are extracted from entries of the index, where the key belongs to that next range, until that next range is exhausted.

Abstract: Heterogeneous computer systems are computer systems with different storage architectures, computer systems with different central processing units (CPUs), computer systems with different disk organization methods, computer systems with different access methods, computer systems that use different controller interfaces etc. These systems share data so that every one of the said computer systems can access the data independently, not relying on services from the others. A single copy of the data is maintained, as opposed to replicated data that is used, in some cases to overcome the same needs. Every system has direct access to the shared data, through the use of emulators that enable applications on every system to use the desired interfaces to the data, disguised as the ordinary local interfaces. An example is the accessing an IBM mainframe's DB2 data base from a UNIX environment.