This glossary defines many of the terms and abbreviations used
in this publication. If you do not find the term you are looking for, refer
to the index or to the Dictionary of Computing, SC20–1699.
- access method
- The part of the DDM architecture that accepts commands to access and process
the records of a file.
- alternate index file
- A file that has a different key path over a base file. The base file can
be a keyed, direct, or sequential file.
- API
- Application Programming Interface.
- CDRA
- Character Data Representation Architecture.
- data description
- Specification of the layout of data. The data description of data stored
in a file can be viewed as a file attribute.
- data stream
- All data transmitted through a data channel in a single read or write
operation.
- direct file
- A file that contains records that have a relationship between the contents
of the record and the record position at which the record is stored.
- LAN
- Local area network.
- local area network
- LAN.
- protocol
- A set of rules to be followed by communication systems.
- record
- The basic unit of data stored in a file and transferred between DDM source
and target servers.
- sequential file
- A file in which records are arranged in exactly the same sequence as they
were stored into the file.
- source system
- A system that requests access to data on another system. It is the “source”
of the request.
- stream file
- Stream files contain strings of bytes that can be accessed according to
their relative position within the file.
- target system
- The system that contains data that is being accessed by another system.
- VSAM
- Virtual storage access method.