ΔΗΜΟΣΙΕΥΣΕΙΣΓιάννης Ιωαννίδης
1989
We investigate the role of commutativity in query processing of linear recursion. We give a sufficient condition for two linear, function-free, and constant-free rules to commute. The condition…
In the majority of research work done on logic programming and deductive databases, it is assumed that the set of rules defined by the user is consistent, i.e., that no contradictory facts can be…
1988
We have developed some efficient algorithms for computing the transitive closure of a directed graph. This paper presents the algorithms for the problem of reachability. The algorithms, however,…
As the size and complexity of processing and manufacturing systems increases, the need for Database Management Systems (DBMS) that meet the special needs of studies that experiment with such…
Consider a function-free and constant free Horn clause [Gall 78]... (cannot display further due to mathematical functions that cannot be expressed in text - please donwload paper instead).
We describe the design and implementation of BERMUDA, which is a system interfacing Prolog to the Britton-Lee Intelligent Database Machine (IDM). We discuss several architectural issues faced by such…
1987
Query optimizers of future database management systems are likely to face large access plan spaces in their task. Exhaustively searching such access plan spaces is unacceptable. We propose a query…
1986
A virtual relation (or view) can be defined with a recursive Horn clause that is a function of one or more base relations. In general, the number of times such a Horn clause must be applied in order…
Query processing in the presence of recursively defined views usually involves some form of iteration. For example, computing the transitive closure of a tree involves iterating N times, where N is…
Recursion in the database context has traditionally been studied under the formalism of 1-st order logic. In particular, the bulk of the research effort in the last few years has been devoted to…
1985
A virtual relation (or view) can be defined with a recursive statement that is a function of one or more base relations. In general, the number of times such a statement must be applied in order to…
1984
This paper proposes extensions to a relational database system to support the selection and execution of algorithms for shortest path search problems. An expert system can employ this extended DBMS…
