Disable any triggers on the table Drop indexes before starting the import, re-create them afterwards. (It takes much less time to build an index in one pass than it does to add the same data to it progressively, and the resulting index is much more c…

PostgreSQL相关的软件,库,工具和资源集合. 备份 wal-e - Simple Continuous Archiving for Postgres to S3, Azure, or Swift by Heroku Barman - Backup and Recovery Manager for Postgres by 2ndQuadrant GUI pgAdmin - Postgres Administration and Management GUI phpPgAdmin - The…

利用window.performance.timing进行性能分析   性能分析... window.performance.timing中相关属性语义: // .navigationStart 准备加载页面的起始时间 // .unloadEventStart 如果前一个文档和当前文档同源,返回前一个文档开始unload的时间 // .unloadEventEnd 如果前一个文档和当前文档同源,返回前一个文档开始unload结束的时间 // .redirectStart 如果有重定向,这里是重定…

性能分析... window.performance.timing中相关属性语义: // .navigationStart 准备加载页面的起始时间 // .unloadEventStart 如果前一个文档和当前文档同源,返回前一个文档开始unload的时间 // .unloadEventEnd 如果前一个文档和当前文档同源,返回前一个文档开始unload结束的时间 // .redirectStart 如果有重定向,这里是重定向开始的时间. // .redirectEnd 如果有重定向,这里是重定…

前几天看了一篇文章<High Performance JSON PostgreSQL vs. MongoDB> 发布在Percona Live Europe 2017 作者是<Dominic Dwyer Wei Shan Ang>,作者的观点是PostgreSQL更好,恰巧没有玩过postgresql,仅仅听说过. 码农的第一特征就是相信实验,故postgresql走起 上一篇文章<mongodb索引--1亿条记录的查询从55.7秒到毫秒级别> 我们做了一个mongo的…

小结: 1.覆盖索引 回表 2. All indexes in PostgreSQL are secondary indexes, meaning that each index is stored separately from the table's main data area (which is called the table's heap in PostgreSQL terminology). This means that in an ordinary index scan, ea…

Prior to the publication of the IBM technical paper behind what commonly known today as the Doherty Threshold[1] "... it was thought that a relatively slow response, up to two seconds, was acceptable because the person was thinking about the next tas…

本文介绍Wifi 分析线路二:在Setting中打开WiFi功能.扫描网络以及连接网络的流程. WifiSettings 无线网络设置界面 WifiEnabler 相当于无线网络设置开关 WifiDialog 显示的无线网络配置信息由WifiConfigController 来控制和管理 Scanner 用于处理和无线网络扫描相关的工作 1.Settings 操作 无线网络设置界面UI 初始化过程中,WifiSettings 的onActivityCreated() 方法被调用: public…

  SANDY BRIDGE SPANS GENERATIONS Intel Focuses on Graphics, Multimedia in New Processor Design By Linley Gwennap  {9/27/10-01} ................................................................................................................... Intel’s…

Milan Ikits University of Utah Joe Kniss University of Utah Aaron Lefohn University of California, Davis Charles Hansen University of Utah This chapter presents texture-based volume rendering techniques that are used for visualizing three-dimensional…