Design and Implementation of a Graphical SQL with Generic Capabilities
1993; Springer Nature; Linguagem: Inglês
10.1007/978-1-4471-3423-7_6
ISSN1431-1682
Autores Tópico(s)Semantic Web and Ontologies
ResumoIQL (Interactive Query Language) provides interactive formulation and optimization of relational queries. It has been implemented as a part of an integrated environment for the design of databases using Graphtalk™, an object-oriented Graphs Base Management System of Rank Xerox. IQL’s Query Interface supports fast and easy formulation of full SQL queries and update transactions by using a novel object-oriented representation of query concepts. A query is a graph made up of a set of tree-like expressions (clauses, predicates, arithmetic and boolean expressions) specified at different graphical levels on subsets of relations of a database schema. The power and flexibility of query graphs derive from the independent meta-modeling of implied formalisms, so complex queries may be expressed graphically in their entirety. Querying performances are improved in several ways: 1) syntax and consistency issues are permanently verified during formulation, 2) users dispose of a variety of abstraction mechanisms like the denomination of queries (or expressions) and the use of parameters, thus permitting modular and generic reusability, even on a different database schema, and 3) a subclass of query optimization mechanisms may be applied to generate compiled versions of lower cost equivalent queries in relation to a given operational context (i.e., access and data schemata).
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