An optimization of queries in distributed database systems
نویسندگان
چکیده
منابع مشابه
An Optimization of Queries in Distributed Database Systems
This paper addresses the processing of a query in distributed database systems using a sequence of semijoins. The objective is to minimize the intersite data traffic incurred by a distributed query. A method is developed which accurately and efficiently estimates the size of an intermediate result of a query. This method provides the basis of the query optimization algorithm. Since the distribu...
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The query optimizer is widely considered to be the most important component of a database management system. it is a process of producing an optimal (close to optimal) query execution plan which represents an execution strategy for the query. It is responsible for taking a user query and searching through the entire space of equivalent execution plans for a given user query and returning the ex...
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This paper describes how nested queries in the SQL language are processed by R*, an experimental adaptation to the distributed environment of the well-known centralized relational DBMS, System R. Nested queries are queries in which a predicate references the result of another query block (SELECT...FROM...WHERE...), called a subquery block (subQB). SubQBs may themselves contain one or more subQB...
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The query optimizer is widely considered to be the most important component of a database management system. It is responsible for taking a user query and searching through the entire space of equivalent execution plans for a given user query and returning the execution plan with the lowest cost. This plan can then be passed to the executer, which can carry out the query. Plans can vary signifi...
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ژورنال
عنوان ژورنال: Journal of Parallel and Distributed Computing
سال: 1986
ISSN: 0743-7315
DOI: 10.1016/0743-7315(86)90001-8