The database auto-design is an important problem in database research.In this paper we propose some new ideas and an approach called“logic approach”to implement the database auto-design.Given a relational scheme and...The database auto-design is an important problem in database research.In this paper we propose some new ideas and an approach called“logic approach”to implement the database auto-design.Given a relational scheme and a set of the functional dependencies for the relation we can obtain all of the functional dependencies and key for the relation and determine the normal form the relation satisfies.展开更多
F-logic language is a logic database language based on frame logic. It is powerful in expressing object-oriented features. However, there was littIe work discussing its capability of manipulating complex objects. In t...F-logic language is a logic database language based on frame logic. It is powerful in expressing object-oriented features. However, there was littIe work discussing its capability of manipulating complex objects. In this paper, the authors compare the capability of F-logic with that of logic database languages represented by COL. Through two pairs of semantic-preserving transformations, F-logic programs and their Herbrand interpretations can be transformed into COL programs and their corresponding Herbrand interpretations, and vice versa. Also, the effects of negation are discussed. The results of this paper indicate that, without consideration of the effects of OID generating, F-logic language has the same power in manipulating complex objects as COL, LDL1,and ELPS.展开更多
文摘The database auto-design is an important problem in database research.In this paper we propose some new ideas and an approach called“logic approach”to implement the database auto-design.Given a relational scheme and a set of the functional dependencies for the relation we can obtain all of the functional dependencies and key for the relation and determine the normal form the relation satisfies.
文摘F-logic language is a logic database language based on frame logic. It is powerful in expressing object-oriented features. However, there was littIe work discussing its capability of manipulating complex objects. In this paper, the authors compare the capability of F-logic with that of logic database languages represented by COL. Through two pairs of semantic-preserving transformations, F-logic programs and their Herbrand interpretations can be transformed into COL programs and their corresponding Herbrand interpretations, and vice versa. Also, the effects of negation are discussed. The results of this paper indicate that, without consideration of the effects of OID generating, F-logic language has the same power in manipulating complex objects as COL, LDL1,and ELPS.