Results 231 to 240 of about 34,853 (265)
Bringing order to query optimization [PDF]
ACM SIGMOD Record, 2002 A variety of developments combine to highlight the need for respecting order when manipulating relations. For example, new functionality is being added to SQL to support OLAP-style querying in which order is frequently an important aspect. The set- or multiset-based frameworks for query optimization that are currently being taught to database students ...
Giedrius Slivinskas +2 more
openaire +2 more sources
Some of the next articles are maybe not open access.
Related searches:
Related searches:
Optimization of schemaSQL queries
Proceedings 2001 International Database Engineering and Applications Symposium, 2002We study the optimization of schemaSQL and schemaSQL-like languages. Our starting point is an extended relational algebra which can be used to implement schemaSQL and similar languages. We study transformation (rewrite) rules for the extended algebra which are used in a prototype cost-based optimizer for the rewriting of expressions into more efficient
Keir B. Davis, Fereidoon Sadri
openaire +1 more source
Query Optimization in Database Systems
ACM Computing Surveys, 1984Summary: Efficient methods of processing unanticipated queries are a crucial prerequisite for the success of generalized database management systems. A wide variety of approaches to improve the performance of query evaluation algorithms have been proposed: logic-based and semantic transformations, fast implementations of basic operations, and ...
Matthias Jarke, Jürgen Koch
openaire +2 more sources
2005
We propose and solve the optimal-location query in spatial databases. Given a set S of sites, a set O of weighted objects, and a spatial region Q, the optimal-location query returns a location in Q with maximum influence. Here the influence of a location l is the total weight of its RNNs, i.e.
Yang Du, Donghui Zhang, Tian Xia 0001
openaire +1 more source
We propose and solve the optimal-location query in spatial databases. Given a set S of sites, a set O of weighted objects, and a spatial region Q, the optimal-location query returns a location in Q with maximum influence. Here the influence of a location l is the total weight of its RNNs, i.e.
Yang Du, Donghui Zhang, Tian Xia 0001
openaire +1 more source
Optimization and evaluation of disjunctive queries
IEEE Transactions on Knowledge and Data Engineering, 2000It is striking that the optimization of disjunctive queries-i.e. those which contain at least one OR-connective in the query predicate-has been vastly neglected in the literature, as well as in commercial systems. In this paper, we propose a novel technique, called bypass processing, for evaluating such disjunctive queries.
Claussen, Jens +4 more
openaire +3 more sources
Stored queries—a data organization for query optimization
Data & Knowledge Engineering, 1988Abstract Queries stored together with their actual responses give a possibility of improvement of database system performance regardless of the complexities of user requests and the data model employed. The main properties of such a data organization as well as its essential problems are outlined, particularly the problem of updating stored queries ...
Wiktor Rzeczkowski, Kazimierz Subieta
openaire +1 more source
Semantic query optimization for tree and chain queries
IEEE Transactions on Knowledge and Data Engineering, 1994Semantic query optimization, or knowledge-based query optimization, has received increasing interest in recent years. The authors provide an effective and systematic approach to optimizing queries by appropriately choosing semantically equivalent transformations.
Wei Sun 0002, Clement T. Yu
openaire +1 more source
Exploiting uniqueness in query optimization
CASCON First Decade High Impact Papers on - CASCON '10, 2002Consider an SQL query that specifies duplicate elimination via a DISTINCT clause. Because duplicate elimination often requires an expensive sort of the query result, it is often worthwhile to identify unnecessary DISTINCT clauses and avoid the sort altogether.
G. N. Paulley, Per-Åke Larson
openaire +2 more sources
Optimizing queries with materialized views
Proceedings of the Eleventh International Conference on Data Engineering, 1999While much work has addressed the problem of maintaining materialized views, the important question of optimizing queries in the presence of materialised views has not been resolved. In this paper, we analyze the optimization question and provide a comprehensive and efficient solution.
Surajit Chaudhuri +3 more
openaire +1 more source
Query Optimization for a Graph Database with Visual Queries
2006We have constructed a graph database system where a query can be expressed intuitively as a diagram. The query result is also visualized as a diagram based on the intrinsic relationship among the returned data. In this database system, CORAL plays the role of a query execution engine to evaluate queries and deduce results.
Greg Butler +3 more
openaire +1 more source