Efficient Query Evaluation Through Access-Reordering
نویسندگان
چکیده
Reorganising the index of a search engine based on access frequencies can significantly reduce query evaluation time while maintaining search effectiveness. In this paper we extend access-ordering and introduce a variant index organisation technique that we label accessreordering. We show that by access-reordering an inverted index, query evaluation time can be reduced by as much as 62% over the standard approach, while yielding highly similar effectiveness results to those obtained when using a conventional index.
منابع مشابه
Extending the Algebraic Framework of Query Processing to Handle Outerjoins
A crucial part of relational query optimization is the reordering of query processing for more efficient query evaluation. The reordering may be explicit or implicit. Our major goal in this paper is to describe manipulation rules for queries that include outerjoins, and views or nested subqueries. By expressing queries and processing Strategies in terms of relational algebra, one can use the or...
متن کاملFramework-Based Development and Evaluation of Cost-Based Native XML Query Optimization Techniques
Reflecting on the history of database management systems reveals that cost-based query optimization has been the dominating method for effectively answering complex queries on large documents. Native XML database management systems provide an efficient infrastructure for storing, indexing, and querying large XML documents. Even though such systems can choose from a huge set of structural join o...
متن کاملReordering Query Execution in Tertiary Memory Databases
In the relational model the order of fetching data does not a ect query correctness. This exibility is exploited in query optimization by statically reordering data accesses. However, once a query is optimized, it is executed in a xed order in most systems, with the result that data requests are made in a xed order. Only limited forms of runtime reordering can be provided by low-level device ma...
متن کاملDiscovering Popular Clicks\' Pattern of Teen Users for Query Recommendation
Search engines are still the most important gates for information search in internet. In this regard, providing the best response in the shortest time possible to the user's request is still desired. Normally, search engines are designed for adults and few policies have been employed considering teen users. Teen users are more biased in clicking the results list than are adult users. This leads...
متن کاملStatistics & Clustering Based Framework for Efficient XACML Policy Evaluation
The adoption of XACML as the standard for specifying access control policies for various applications, especially web services is vastly increasing. A policy evaluation engine can easily become a bottleneck when enforcing large policies. In this paper we propose an adaptive approach for XACML policy optimization. We proposed a clustering technique that categorizes policies and rules within a po...
متن کامل