Allocation of Join and Semi Join Operations based on Dynamic Selectivity Factor in a Distributed Database Query
نویسندگان
چکیده
منابع مشابه
Efficient Query Optimization for Distributed Join in Database Federation
Database federation is one approach to data integration, in which a middleware, called mediator, provides uniform access to a number of heterogeneous data sources. For the mediator, two key components are query rewriter and query optimizer. In this thesis, we focus on the query optimizer part, particularly, on cost-based query optimization for distributed joins over database federation. One imp...
متن کاملJoin Query Optimization in Parallel Database Systems
In this paper we present a new framework for studying parallel query optimization. We first note that scheduling and optimization must go together in a parallel environment. We introduce the concept of response time envelopes which integrates scheduling and optimization. We show that it can be used effectively to develop parallel query optimization algorithms which have same order of complexity...
متن کاملOptimizing Join Query In Distributed Databases
Query Optimization is to use the best plan for the query that improves the performance of the query. Query Optimization is difficult in distributed databases as compared to centralized databases. Queries in distributed databases are effected by factors such as insertion methods of the data into the remote server and transmission time between servers. Response time of the query depends upon the ...
متن کاملParallel Database Sort and Join Operations Revisited on Grids
Based on the renowned method of Bitton et al. (see [1]) we develop a concise but comprehensive analytical model for the well-known Binary Merge Sort, Bitonic Sort, Nested-Loop Join and Sort Merge Join algorithm in a Grid Environment. We concentrate on a limited number of characteristic parameters to keep the analytical model clear and focused. Based on these results the paper proves that by sma...
متن کاملAcceleration of Join Operations by a Relational Database Processor, RINDA
Fast join methods implemented in a relational database processor, RINDA, are described. RINDA performs complex queries including sorts and joins with specialized hardware. Join operations by RINDA are executed in three phases: filtering phase, sorting phase and merge-join phase. In the filtering phase, unjoinable tuples are removed with hashed-bit-arrays. Remaining tuples are sorted in the sort...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: International Journal of Computer Applications
سال: 2014
ISSN: 0975-8887
DOI: 10.5120/17212-7438