Titlebook: Semantics in Databases; Second International Leopoldo Bertossi,Gyula O. H. Katona,Bernhard Thal Conference proceedings 2003 Springer-Verlag

思想

Semantic Classifications of Queries to Relational Databases,aic (hence, semantic) characterizations of equality of theories for databases, in . and in weaker logics. We introduce an abstract notion of . for databases, as equality in the theories for a given logic and we define different sub-classes of queries by requiring that the queries in a given sub-clas

含糊其辞

0302-9743 s. Among the classes of databases dealt with are deductive databases, relational databases, distributed information systems, and tree-structured data..978-3-540-00957-3978-3-540-36596-9Series ISSN 0302-9743 Series E-ISSN 1611-3349

interrogate

Characterizing and Computing Semantically Correct Answers from Databases with Annotated Logic and Aorder queries. Both the annotated logic and the logic programming approaches work for any set of universal and referential integrity constraints. Optimizations of the logic programs are also analyzed.

不可知论

Flatus

Conflict

比喻好

Null Values in Relational Databases and Sure Information Answers, world semantics. The focus is on the . and the . interpretation of null values. A new semantics for the . interpretation of nulls is proposed taking into account a problem arising in connection with the closed world assumption. Results are applied to the query language SQL.

真繁荣

Automata- and Logic-Based Pattern Languages for Tree-Structured Data,irst-order logic, and monadic second-order logic. It investigates expressiveness as well as the complexity of query evaluation and some optimization problems. Finally, formalisms that allow comparison of attribute values are considered.

engrossed

流动性