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Going to Strata / Hadoop World 2017 San Jose?

Are you attending or considering attending Strata / Hadoop World 2017 San Jose? Are you interested in learning to use R to work with Spark and h2o ? Then please consider signing up for my 3 1/2 hour...

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Hadoop Cluster Setup Recipes #1 VMware Virtual Machine Mount Share Drive

Objective It is very popular for developers create a virtual private Hadoop and Spark cluster environment to perform testing, simulation and all other learning purposes. Especially with the advances...

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Hadoop Weekly Issue #203

05 February 2017 Streaming is a hot topic this week with posts on Kafka Streams, Oracle Data Integrator, StreamSets Collector, and Amazon Kinesis Analytics. Also, there are great posts on performance...

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【redis学习三】简单高可用redis架构实践

redis当前主流版本是redis 2.x 和 redis 3.x,3.0对集群支持比较不错,官方解释如下: Redis是一个开源、基于C语言、基于内存亦可持久化的高性能NoSQL数据库,同时,它还提供了多种语言的API。近日,Redis 3.0在经过6个RC版本后,其正式版终于发布了。Redis...

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【赏码会】Redis的最佳拍档:Jedis

作为Redis官方推荐的三个 Java Client 之一,Jedis推出时间最早,使用最为广泛(Spring默认使用的Redis Client就是Jedis),同时Star数也遥遥领先于另外两个。和其他Redis Client一样,Jedis通过 RESP协议 向Redis发送命令请求和解析响应数据。 源码赏析...

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MongoDB 文档字段增删改

MongoDB 基于CRUD(create,read,update,delete)方式实现了对集合上的文档进行增删改查。对于集合上字段的增删改,可以使用 s e t 或 者 unset修改器来实现。也可以使用文档替换的方式来实现。本文主要描述集合上字段的增删改,以及基于选项upsert的更新。 关于MongoDB文档更新可以参考:MongoDB 文档更新 一、语法描述...

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Storing and querying trillions of events

This is a second post in series describing our recent infrastructure / architecture transition in Plumbr. The first part focused upon event capturing part of the architecture. In the current post we...

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Getting Started With Cassandra: Using CQL API and CQLSH

Apache Cassandra is one of the most popular open-source distributed database systems available. It was designed with the goal of handling large amounts of data stored in many servers distributed...

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[ Laravel 5.4 文档 ] 核心概念 ―― 契约(Contracts)

1、简介 Laravel 中的契约是指框架提供的一系列定义核心服务的接口。 例如, Illuminate\Contracts\Queue\Queue 契约定义了队列任务需要实现的方法, Illuminate\Contracts\Mail\Mailer 契约定义了发送邮件所需要实现的方法。 每一个契约都有框架提供的相应实现。例如,Laravel 为队列提供了多个驱动的实现,邮件则由...

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In-memory noSQL DBMS Client in Big Data Cluster

This is guest post by Sergei Sheinin , creator of the 2DX Web UI Database Cluster Framework , a low latency big data cluster with in-memory noSQL DBMS Web Browser client. When I began working in the...

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What is Hadoop - An Easy Explanation For Absolutely Anyone

Originally posted here by Bernard Marr . When you learn about Big Data you will sooner or later come across this odd sounding word: Hadoop - but what exactly is it? Put simply, Hadoop can be thought...

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10 GitHub samples with Azure DocumentDB you shouldn’t miss!

Azure DocumentDB is a fully managed, multi-model, scalable, queryable, schema-free NoSQL database service built for modern applications: mobile, web, IoT, bots, AI, etc. Recently, I went on GitHub and...

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Go Newsletter Issue #146

Featured The State of Go (in February 2017) video Go 1.8 is due next week, so this is a good time to take stock of where we’re at now. In a 35 minute talk, Francesc Campoy covers key changes in 1.8, GC...

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MyBatis和Hibernate的比较 数据库 数据库学习 MyBatis Hibernate

MyBatis和Hibernate的比较1、开发对比开发速度 hibernate的真正掌握要比Mybatis来得难些。Mybatis框架相对简单很容易上手,但也相对简陋些。个人觉得要用好Mybatis还是首先要先理解好Hibernate。 开发社区 Hibernate...

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数据表字段的删除或添加语句 数据库 数据库学习 数据表字段 删除添加语句

数据表字段的删除或添加语句,以下操作是在已有的mysql数据库表中进行 删除语句: alter table 表名 drop column 字段名; 如: alter table zgglmag drop column dlcode;添加语句: alter table 表名 add column 字段名 类型 默认缺省值 备注;如: alter table `user_movement_log`...

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MyBatis快速入门 数据库 数据库学习 MyBatis MyBatis入门

MyBatis快速入门,Mybatis的功能架构分为三层(图片借用了百度百科): 1) API接口层:提供给外部使用的接口API,开发人员通过这些本地API来操纵数据库。接口层一接收到调用请求就会调用数据处理层来完成具体的数据处理。 2) 数据处理层:负责具体的SQL查找、SQL解析、SQL执行和执行结果映射处理等。它主要的目的是根据调用的请求完成一次数据库操作。 3)...

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redis范围查询应用 数据库 数据库学习 Redis redis范围查询

redis范围查询应用。需求 根据IP找到对应的城市 原来的解决方案 oracle表(ip_country): 查询IP对应的城市: 1.把a.b.c.d这样格式的IP转为一个数字,例如为把210.21.224.34转为3524648994 2. select city from ip_country where ipstartdigital <= 3524648994 and...

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LINQ简介 数据库 数据库学习 LINQ简介 LINQ查询

一. 第一个LINQ查询 1. Language Integrated Query(LINQ) 示例 A. 创建一个控制台程序 B. 打开主源文件Program.cs C. Visual C# 2010默认在Program.cs中包含Linq名称空间using System;using System.Collections.Generic;using System.Linq;using...

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数据库问题之子查询可以提高速度 数据库 数据库学习 数据库问题 子查询 子查询速度

数据库问题之子查询可以提高速度,今天在公司碰到一情况,上面领导要求公司系统由mysql改成mssql,我不知道为什么要求这样做,难道是因为MySQL在一些地方不如MSSQL好吗,还是有其他的原因。没办法这是任务,花了两天的时间把表,和表里的数据已经迁移到MSSQL上了,几十个存储过程和几张视图花了一周多的时间快重写完了。自己在测试过程中发现MySQL比MSSQL慢很多,以前在网上碰到的是MySQL是...

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unionall和union的区别 数据库 数据库学习 unionall union

unionall和union的区别。

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