Synonyms Query evaluation ; Query planning and execution Definition In an (object) relational database management system (DBMS) query processing comprises all steps of processing a user submitted query including its execution to compute the requested result. Usually, a user query – for example a ...
由于SQL是声明式语言(declarative),用户只告诉了DBMS想要获取什么,但没有指出如何计算。因此,DBMS需要将SQL语句转换成可执行的查询计划(Query Plan)。但是对同样的数据可以有多种查询方案,性能也差距很大,查询优化器(Query Optimizer)的任务就是从给定的查询中选择一个最优的方案。 最早的查询优化器实现是IBM在1970s...
By selecting the optimal execution plan for processing data, Query Optimization significantly improves database performance and minimizes latency. FAQs What is Query Optimization?Query Optimization is an aspect of DBMS that determines the most efficient way to execute a given query. ...
[12] G. Graefe. Encapsulation of Parallelism in the Volcano Query Processing System. In SIGMOD, 1990. [13] G. Graefe. The Cascades Framework for Query Optimization. IEEE Data Eng. Bull., 18(3), 1995. [14] G. Graefe and W. J. McKenna. The Volcano Optimizer Generator: Extensibility a...
Transaction Processing Performance Council, TPC Benchmark D (Decision Support) Standard Specification Revision 1.1, December, 1995 R.H.Wolniewicz and G.Graefe, Algebraic Optimization of Computations over Scientific Databases,Proc. Intl’ Conf. On Very Large Data Bases, Dublin, Ireland, August 1993,...
A green framework for DBMS based on energy-aware query optimization and energy-efficient query processing In this study, we report our recent efforts on this issue, with a focus on energy-aware query optimization and energy-efficient query processing. Firstly... B Guo,J Yu,B Liao,... - 《...
In SQL Server, theOPTION (LOOP JOIN)hint specifies the join method: SELECT*FROMordersINNERJOINcustomersONorders.customer_id=customers.idOPTION(LOOPJOIN); These hints override the default query optimization, improving performance in specific scenarios. ...
Furthermore, we extensively evaluate linear algebra query processing and operator fusion utilizing the widely-used Star Schema and TPC-DI benchmarks. Through comprehensive evaluations, we demonstrate the effectiveness and potential of our approach in improving the efficiency of data processing and machine...
Using profile information to assist advanced compiler optimization and scheduling. In Proc. of Advances in Languages and Compilers for Parallel Processing . Pitman Publishing, 1993.CHEN, W. Y., MAHLKE, S., WARTER, N., AND HANK, R... WY Chen,RA Bringmann,SA Mahlke,... - Springer-Verlag...
Processing Models定义了query plan的执行从什么方向读取以及算子(operator)之间传递什么样的数据。 model有两种调用算子的方式(函数调用的方向) 自顶向下:较常用 自下而上:能够更好的控制管道中的寄存器或缓存? Processing Model Iterator Model(又叫火山模型) ...