Structures - Network

Developed in the 1970's The network data model has been heavily influenced by the CODASYL specifications, produced 1971 by COnference of DAta SYstem Languages - a voluntary committee of hardware and software vendors, universities and major developers. Terms: Pointers: connections between the nodes Schema: is a named collection of files, and sets of files. Subschema: customised view of the database (Dynaset in MS-Access)

Features

• An item may have more than one "parent".
• Typically implemented using pointers ( a reference to the actual position of a record in a file), so a reference to an employee on a time sheet is via a pointer to a record in the employee file.
  

Examples:

• IDMS/R and DATACOMDB
• The internet can be considered to be one enormous network database.

Note: Database structures that are of a network nature are mostly nowadays implemented using relational database tables with joins.

[Rev: 12/04/99] Jun-97 © 1997-99 V/2-Com (Verhaart), P O Box 8415, Havelock North, New Zealand.