Titlebook: LOGIDATA+: Deductive Databases with Complex Objects; Paolo Atzeni Book 1993 Springer-Verlag Berlin Heidelberg 1993 Complex Objects.Databas

密切关系

出生

The LOGIDATA+ model,can be built by means of the recursive use of set, tuple, and sequence constructors. As usual in database frameworks, the model has an intensional level (with the notion of scheme) and an extensional level, (with the notion of instance). A data definition language for the description of LOGIDATA+ schemes is also presented.

很是迷惑

Nuance

狗窝

Management of extended update operations, for specifying complex update transactions. The resulting language is first informally presented by using several examples. Then, the syntax and the semantics are formally given. Finally, an abstract interpreter is proposed, and its correctness is discussed.

prediabetes

Taxonomic reasoning in LOGIDATA+,ips (i.e. compute . between classes on the basis of their descriptions. From a theoretical point of view, this approach makes it possible to give a formal definition of . to a schema, while, from a pragmatic point of view, it is possible to automatically . a new class in the correct position of a given taxonomy.

谦虚的人

Taxonomic reasoning with cycles in LOGIDATA+,d and the necessary algorithms to detect incoherence and compute subsumption in a LOGIDATA. schema are given. Some examples of subsumption computation show its feasibility for schema design and validation.

resilience

Introducing taxonomic reasoning in LOGIDATA+,ng us to deal with a form of incomplete knowledge in a way that is semantically correct. After introducing defined classes and the notion of interpretation function, it is possible to formally define the concept of subsumption, an inference technique that makes it possible reasoning about objects and classes on the basis of their descriptions.

heterodox

mutineer

Book 1993research actionfunded by the Italian national research council CNR.Theaim of the LOGIDATA+ project is the definition ofadvanced database systems which significantly extend thefunctionalities of the current systems, with specificreference to the application areas for which relationalsystemsare not co