Data organization and storage

The organization of data is important to the z/TPF system. The performance objectives of the z/TPF system must be achieved while, regardless of the actual physical database structure, allowing the applications to access data as simple, logical structures. In meeting these objectives, the z/TPF system assumes the responsibility of allocating sets of data to physical devices and for converting data references to physical locations.

Some of the factors, that must be considered with regard to data organization in the z/TPF system are:
  • Coordination of the updates to any specific record by:
    • Multiple I-stream engines in a central processor complex (CPC)
    • Multiple CPCs in a loosely coupled complex
  • The ability to expand the capacity of the database by adding module (sometimes referred to as DASD) hardware
  • The ability to take advantage of new module technology by not requiring the database to be all one type of module hardware
  • The ability to change the physical layout of modules based on changes required by application design; that is, the location of fixed and pool files can be changed if necessary.
The following introduces the strategy and techniques used by the z/TPF system for data organization in the following areas:
  • Data located on modules
  • Data held in main storage.