EXTENDING SQL WITH GENERALIZED TRANSITIVE CLOSURE

被引：11

作者：

DAR, S

AGRAWAL, R

机构：

[1] AT&T BELL LABS,MURRAY HILL,NJ 07974

[2] IBM CORP,ALMADEN RES CTR,SAN JOSE,CA 95120

来源：

IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERING | 1993年 / 5卷 / 05期

关键词：

ALPHA-EXTENDED RELATIONAL ALGEBRA; DEDUCTIVE DATABASES; RECURSION; SQL; TRANSITIVE CLOSURE;

D O I：

10.1109/69.243510

中图分类号：

TP18 [人工智能理论];

学科分类号：

081104 ; 0812 ; 0835 ; 1405 ;

摘要：

We present SQL/TC, an extension of SQL, to allow the expression of generalized transitive closure queries. The extension permits the user to pose queries that compute paths between two points and information associated with these paths. Such queries may specify selections on arcs, paths, or sets of paths. The output of a query may include the aggregation of information for different paths between the same endpoints. Our notation is declarative, preserves the spirit of SQL, and allows a declarative and concise formulation of transitive closure queries.

引用

页码：799 / 812

页数：14