AV Aho, C Beeri, JD Ullman - ACM Transactions on Database Systems …, 1979 - dl.acm.org
Answering queries in a relational database often requires that the natural join of two or more relations be computed. However, the result of a join may not be what one expects. In this …
S Chaudhuri, K Shim - ACM Transactions on Database Systems (TODS), 1999 - dl.acm.org
Relational databases provide the ability to store user-defined functions and predicates which can be invoked in SQL queries. When evaluation of a user-defined predicate is …
AK Chandra, PM Merlin - Proceedings of the ninth annual ACM …, 1977 - dl.acm.org
We define the class of conjunctive queries in relational data bases, and the generalized join operator on relations. The generalized join plays an important part in answering conjunctive …
Relational joins are at the core of relational algebra, which in turn is the core of the standard database query language SQL. As their evaluation is expensive and very often dominated …
Introduction 314 (the second operand of the join) is the result of a join that must be materialized in memory or-if it is too big-on disk. The heuristic saves this materialization, but …
DJ Rosenkrantz, HB Hunt III - … of the sixth international conference on …, 1980 - dl.acm.org
Several aspects of relational database systems require the processing of predicates. For example, predicates can be tested for satisfiability (as in processing predicate locks), and …
PAV Hall - IBM Journal of Research and Development, 1976 - ieeexplore.ieee.org
This paper examines optimization within a relational data base system. It considers the optimization of a single query defined by an expression of the relational algebra. The …
AV Aho, Y Sagiv, JD Ullman - SIAM Journal on Computing, 1979 - SIAM
Many database queries can be formulated in terms of expressions whose operands represent tables of information (relations) and whose operators are the relational operations …
Recently, Gottlob, Lee, Valiant, and Valiant (GLVV) presented an output size bound for join queries with functional dependencies (FD), based on a linear program on polymatroids …