MS SQL Server is used as an experimental approach to examine the proposed techniques.Haxhijaha, BlertaAjdari, JauminRaufi, BujarZenuni, XhemalIsmaili, FlorieInternational Journal on Information Technologies & Security
Query optimization for such system is a challenging and important problem. In this paper we describe the Query Optimizer inside the SQL Server Parallel Data Warehouse product (PDW QO). We leverage existing QO technology in Microsoft SQL Server to implement a cost-based optimizer for distributed ...
9.对这个最优plan应用post-optimization rules,论文没有给出这个rules是什么,个人理解可能是topN之类的规则。 10.以bottom-up方式生成DSQL 11.对DSQL应用post-DSQL-generation rules 12.返回最终DSQL执行计划 Cost Model PDW优化器的代价评估模型中计算了data movement算子的代价。 Cost Model假设 从0开始建立代价评...
SQL Server PDW(Parallel DataWarehouse)是SQL Server的MPP版本,目前已经演进为Azure DataWarehouse部署在云上,用来存储大容量数据并处理分析型查询。总体上是一个share nothing的经典MPP架构,类似于Greenplum,它也会利用单机SQL Server作为其sharding data和meta data的存储+计算实例。 基本架构 集群中每个节点都部署单个...
Query Optimization 优化: SQL Server使用基于成本的优化器,并使用成本估算模型来估算每个候选计划的成本 实质上,查询优化是将树表示中表达的逻辑查询操作映射到可由执行引擎执行的物理操作的过程。 查询优化过程的最终产品是一个执行计划:一个由多个物理操作符组成的树,该树包含执行引擎为了从数据库中获得所需结果而要...
The query processing pipeline in SQL Server for disk-based tables. Query optimization; the role of statistics on memory-optimized tables as well as guidelines for troubleshooting bad query plans. The use of interpreted Transact-SQL to access memory-optimized tables. Considerations...
We’ve been introduced to the fundamental operations of the SQL Server Query Optimizer, from parsing the initial query to how the Query Optimizer tries to find the best possible execution plan for every query submitted to SQL Server. We’ve also looked at the complexity of the optimization proc...
Control node 是集群的入口点,前端应用于control node连接并发送请求,其上有一个PDW engine,做全局性的管理控制:distributed query优化、执行调度管理,DMS管理,权限检查,对外接口。内部的SQL server上有一个shell database,保存全局信息:global metadata/global statistics/数据分布/权限信息,和GP一样没有user data。
that SQL ServerTM will perform in order to fulfill the query and produce the desired resultset. The execution plan is produced by a database engine component called Query Optimizer during the optimization phase of query processing—this takes into account many different factors, such as the search...
Returns detailed statistics about the operation of the SQL Server query optimizer. You can use this view when tuning a workload to identify query optimization problems or improvements. For example, you can use the total number of optimizations, the elapsed time value, and the final cost value ...