Logical Query Processing Phases Summary (8) SELECT (9) DISTINCT (11) <TOP_specification> <select_list> (1) FROM <left_table> (3) <join_type> JOIN <right_table> (2) ON <join_condition> (4) WHERE <where_condition> (…

系列 1 分钟快速使用 Docker 上手最新版 Sentry-CLI - 创建版本 快速使用 Docker 上手 Sentry-CLI - 30 秒上手 Source Maps Sentry For React 完整接入详解 Sentry For Vue 完整接入详解 Sentry-CLI 使用详解 Sentry Web 性能监控 - Web Vitals Sentry Web 性能监控 - Metrics Sentry Web 性能监控 - Trends Sentry Web 前端监控 -…

Summary Description The SQL language is spoken by most database experts, and all relational database products include some dialect of the SQL standard. Nevertheless, each product has its own particular query-processing mechanism. Understanding the wa…

Query Model Query处理有三种方式, 首先是Iterator model,这是最基本的model,又称为volcano,pipeline模式 他是top-down的模式,通过next函数去逐层获取tuple 好处是比较简单,并且很容易做limit iterator的例子,输出一个数据,从top开始调用next,这里第二步需要join,建hashtable,需要把3的数据全部读取上来 第二种方式,materialization model 反其道,这是一种bottom-up的方式,每…

http://www.cs.umd.edu/~amol/talks/VLDB07-AQP-Tutorial.pdf https://www.cis.upenn.edu/~zives/research/aqp-survey.pdf http://db.cs.berkeley.edu/papers/sigmod00-eddy.pdf https://www.cs.umd.edu/class/spring2008/cmsc724/aqp-724.ppt Amol Deshpande, Universi…

http://highlyscalable.wordpress.com/2013/08/20/in-stream-big-data-processing/   Overview In recent years, this idea got a lot of traction and a whole bunch of solutions like Twitter's Storm, Yahoo's S4, Cloudera's Impala, Apache Spark, and Apache Tez…

refer: http://sqlblog.com/blogs/paul_white/archive/2012/04/28/query-optimizer-deep-dive-part-1.aspx    SQL是一种结构化查询语言规范,它从逻辑是哪个描述了用户需要的结果,而SQL服务器将这个逻辑需求描述转成能执行的物理执行计划,从而把结果返回给用户.将逻辑需求转换成一个更有效的物理执行计划的过程,就是优化的过程. 执行SQL的过程: Input Tree We start by looking…

本文地址:http://www.cnblogs.com/egger/archive/2013/05/04/3059374.html   欢迎转载 ,请保留此链接๑•́ ₃•̀๑! 查询操作符(Query Operators)可以让我们写出复杂查询条件,让我们使用的过程更加灵活. 官方文档中使用的“field”单词,RDBMS中是字段的意思,但是MongoDB作为文档数据库,使用的BSON格式作为数据存储格式.field对应key,我这里还是把他翻译成“字段”而不是“键”.若有不妥,请指出. 演示…

DeployingCustomizations in Oracle E-Business Suite Release 12.2 This documentdescribes how to deploy customizations in an Oracle E-Business Suite Release12.2 environment. Follow these instructions to ensure that your customizationsare handled appropr…

Complete list of Microsoft SQL Server trace flags (585 trace flags) REMEMBER: Be extremely careful with trace flags, test in your test environment first. And consult professionals first if you are the slightest uncertain about the effects of your cha…