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The relational data model (RDM) provides a powerful basis for high level language constructs that are used in representing structural (static) and behavioural (dynamic) properties of data intensive applications. A fundamental class of semantic integrity constraints, called interrelational constraints, cannot adequately be represented by structural or behavioural constructs alone. The required structural concept is provided directly by the RDM, but a complementary behavioural concept must be added. The language design issues concern a behavioural concept, called an action skeleton, and its integration with the structural concept. An action skeleton enforces a disciplined design and implementation of database transactions that maintain interrelational constraints. Another design issue concerns the use of syntax to constrain design and implementation choices. |
