DataFlows
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Part II. The ADAMO Data Definition Language - DDL

II.8 - DataFlows

Dataflows may be used to group together logically related ESets. Such a grouping is useful to define ESets to be stored on a file or to be cleared after each event

The dataflow concept is the same as that of the dataflow diagram of structured analysis except that the ADAMO dataflow may contain only ESets and other dataflows.

The first example shows the definition of a dataflow which would be suitable for describing the complete contents of the database for the Cars registration example. Entity sets are distinguished by being enclosed in curly brackets `{}'.

DEFINE DATAFLOW

  RegDB = {Maker},
          {Person},
          {Model},
          {Car}
        : 'Registration Database';

END DATAFLOW
The dataflow has 4 entity sets. It is legal to have an entity set appearing twice in the directed graph which represents the dataflow structure. For example:

DEFINE DATAFLOW

  People  = {Maker},
            {Person};
  FullCar = {Maker},
            {Model},
            {Car}
          : 'All information about a car';
  RegDB   = People,
            FullCar
          : 'Registration Database';

END DATAFLOW
Maker appears indirectly twice in RegDB.

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SF and PP - CERN PTG - ADAMO Reference Manual for Version 3.3 - 13 Dec 93