Deciding implication for functional dependencies in complex-value databases
نویسندگان
چکیده
منابع مشابه
Deciding implication for functional dependencies in complex-value databases
Modern applications increasingly require the storage of data beyond relational structure. The challenge of providing well-founded data models that can handle complex objects such as lists, sets, multisets, unions and references has not been met yet in a completely satisfactory way. The success of such data models will greatly depend on the existence of automated database design techniques that ...
متن کاملHorn clauses and functional dependencies in complex-value databases
We extend Fagin’s result on the equivalence between functional dependencies in relational databases and propositional Horn clauses. It is shown that this equivalence still holds for functional dependencies in databases that support complex values via nesting of records, lists, sets and multisets. The equivalence has several implications. Firstly, it extends a well-known result from relational d...
متن کاملFunctional Dependencies for Object Databases
There is an increasing use of object oriented methods (e.g. [Ru91], [UML97]) for the design of database applications and databases themselves. Like the Entity–Relationship model and its variants, structural models of these methods provide rich modelling concepts for specifying object schemas. Some kinds of integrity constraints, e.g. referential integrity constraints or cardinality constraints ...
متن کاملImplication Problems for Functional Constraints on Databases Supporting Complex Objects
Virtually all semantic or object-oriented data models assume objects have an identity separate from any of their parts, and allow users to define complex object types in which part values may be any other objects. In [20], a more general form of functional dependency is proposed for such models in which component attributes may correspond to descriptions of property paths, called path functiona...
متن کاملArmstrong Databases for Functional and Inclusion Dependencies
An Armstrong database is a database that obeys precisely a given set of sentences (and their logical consequences) and no other sentences of a given type. It is shown that if the sentences of interest are inclusion dependencies and standard functional dependencies (functional dependencies for which the left-hand side is nonempty), then there is always an Armstrong database for each set of sente...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Theoretical Computer Science
سال: 2006
ISSN: 0304-3975
DOI: 10.1016/j.tcs.2006.08.005