Filtering Specific Columns with cut   When working with text files, it can be useful to filter out specific fields. Imagine that you need to see a list of all users in the /etc/passwd file. In this file, several fields are defined, of which the first…

Reference to: http://www.c-sharpcorner.com/UploadFile/skumaar_mca/good-practices-to-write-the-stored-procedures-in-sql-server/ Use proper indentation for the statements in SQL Server. It will improve the readability. Write the proper comments between…

Quandl R Package 通过Quandl API可以快速准确地获取宏观经济数据.(https://www.quandl.com/docs/api) 分享两个国外的优秀网站 R和Python在线免费学习的网站>超赞 高频数据与算法学习 This is Quandl's R package. The Quandl R package uses the Quandl API. The official Quandl R package manual can be found here. Li…

HBase shell commands As told in HBase introduction, HBase provides Extensible jruby-based (JIRB) shell as a feature to execute some commands(each command represents one functionality). HBase shell commands are mainly categorized into 6 parts 1) Gener…

HBASE SHELL命令的使用 在hbase shell客户端有许多的操作命令,今天回顾并且总结一二,希望和广大读者共同进步,并且悉心聆听你们的意见.在此的hbase版本是:HBase 1.2.0-cdh5.10.0. HBASE SHELL命令总结如下: hbase(main):001:0> help HBase Shell, version 1.2.0-cdh5.10.0, rUnknown, Fri Jan 20 12:13:18 PST 2017 Type 'help "COMM…

前言 笔者在分类中的hbase栏目之前已经分享了hbase的安装以及一些常用的shell命令的使用,这里不仅仅重新复习一下shell命令,还会介绍hbase的DDL以及DML的相关操作. hbase的shell操作 启动hbase shell 在hbase的安装目录的bin目录下面启动我们的hbase,执行命令:hbase shell,执行效果以>结束,如下执行效果: [root@mini1 bin]# ./hbase shell SLF4J: Class path contains multi…

, start hdfs [hadoop@alamps sbin]$ ./start-all.sh This script is Deprecated. Instead use start-dfs.sh and start-yarn.sh Starting namenodes on [alamps] alamps: starting namenode, logging to /home/hadoop/app/hadoop-/logs/hadoop-hadoop-namenode-alamps.o…

Apache HBase 是一个高可靠性.高性能.面向列.可伸缩的分布式存储系统,是NoSQL数据库,基于Google Bigtable思想的开源实现,可在廉价的PC Server上搭建大规模结构化存储集群,利用Hadoop HDFS作为其文件存储系统,利用Hadoop MapReduce来处理HBase海量数据,使用Zookeeper协调服务器集群.Apache HBase官网有详细的介绍文档. Apache HBase的完全分布式集群安装部署并不复杂,下面是部署的详细过程: 1.规划HBas…

SQL Fundamentals || Oracle SQL语言 Capabilities of the SELECT Statement(SELECT语句的功能) Data retrieval from data base is done through appropriate and efficient use of SQL. Three concepts from relational theory encompass the capability of the SELECT statem…

Druid is a data store designed for high-performance slice-and-dice analytics ("OLAP"-style) on large data sets. Druid is most often used as a data store for powering GUI analytical applications, or as a backend for highly-concurrent APIs that ne…

INDEX Updating Data The IGNORE Keyword Deleting Data Faster Deletes Guidelines for Updating and Deleting Data Updating Data UPDATE customers SET cust_name = 'The Fudds', cust_email = 'elmer@fudd.com' ; To delete a column's value, you can set it to NU…

CLIs are a fantastic way to build products. Unlike web applications, they take a small fraction of the time to build and are much more powerful. With the web, you can do whatever the developer programmed. With CLIs, you can easily mash-up multiple to…

本博文的主要内容有 .HBase的单机模式(1节点)安装 .HBase的单机模式(1节点)的启动 .HBase的伪分布模式(1节点)安装  .HBase的伪分布模式(1节点)的启动    .HBase的分布模式(3.5节点)安装  .HBase的分布模式(3.5节点)的启动 见博客:     HBase HA的分布式集群部署 .HBase环境搭建60010端口无法访问问题解决方案 ------------- 注意 HBase1.X版本之后,没60010了.       -------------…

源网址http://tech.e2sn.com/oracle-scripts-and-tools/session-snapper 内容: If you want to just download Snapper, you can get it from here: http://blog.tanelpoder.com/files/scripts/snapper.sql(please right click on the file and use Save as... instead of cop…

Scan,get用法 1. get help帮助信息 从下列get用法信息可以看出 get 后面可以跟table表名,rowkey,以及column,value.但是如果想通过get直接获取一个表中的全部数据是做不到的,这种情况就要用到另外一个命令scan. hbase(main):214:0> help 'get' Get row or cell contents; pass table name, row, and optionally a dictionary of column(s),…

本博文的主要内容有 .HBase的单机模式(1节点)安装 .HBase的单机模式(1节点)的启动 .HBase的伪分布模式(1节点)安装   .HBase的伪分布模式(1节点)的启动    .HBase的分布模式(3.5节点)安装  .HBase的分布模式(3.5节点)的启动 见博客:     HBase HA的分布式集群部署 .HBase环境搭建60010端口无法访问问题解决方案 ------------- 注意 HBase1.X版本之后,没60010了.       ------------…

目录 | 上一节 (8.1 测试) | 下一节 (8.3 调试) 8.2 日志 本节对日志模块(logging module)进行简单的介绍. logging 模块 logging 模块是用于记录诊断信息的 Python 标准库模块.日志模块非常庞大,具有许多复杂的功能.我们将会展示一个简单的例子来说明其用处. 再探异常 在本节练习中,我们创建这样一个 parse() 函数: # fileparse.py def parse(f, types=None, names=None, delimite…

权限允许用户访问属于其它用户的对象或执行程序, ORACLE系统提供权限:Object 对象级.System 系统级 查看权限的数据字典: 字典名 含义 ROLE_SYS_PRIVS System privileges granted to roles ROLE_TAB_PRIVS Table privileges granted to roles USER_ROLE_PRIVS Roles accessible by the user USER_TAB_PRIVS_MADE Object pr…

.Option Explicit '强制对模块内所有变量进行声明 Option Private Module '标记模块为私有,仅对同一工程中其它模块有用,在宏对话框中不显示 Option Compare Text '字符串不区分大小写 '指定数组的第一个下标为 1 .On Error Resume Next '忽略错误继续执行 VBA代码,避免出现错误消息 .On Error GoTo ErrorHandler '当错误发生时跳转到过程中的某个位置 . '恢复正常的错误提示 .Applicat…

Add a column with default current date timeALTER TABLE [TableName]ADD CreatedOn DATETIME NOT NULL DEFAULT(GETDATE()); How to Quickly Create a Copy of a Table using Transact-SQL  The easiest way to create a copy of a table is to use a Transact-SQL com…

Visual Studio 2013 中的 LightSwitch 有新增功能,包括更好的团队开发支持以及在构建 HTML 客户端桌面和 Office 365 应用程序方面的改进.本文结合最新发布的Wijmo 5提供的AngularJs进行图解. 基于Visual Studio LightSwitch作为数据源,我们使用Wijmo 5控件快速的创建 AngularJS应用程序. 插入数据记录 业务规则校验 数据记录更新 选择数据记录,点击键盘上删除按键 点击列头,进行数据排序 并发性校验(由Li…

可用的查询设置如下: 参数 描述 举例 conditions Search conditions for the find operation. Is used to extract only those records that fulfill a specified criterion. By default Phalcon\Mvc\Model assumes the first parameter are the conditions. “conditions” => “name LIKE…

commands : show sys connect sys as sysdba or connect system as sysdba logout or disc clear screen or cle screen (utlsample.sql  —> unlock scott tables.sql  —> all tables data.sql  —> add data into tables) connect scott/tiger start C:\utlsample.sq…

1. view the default user account SQL> select username from dba_users; 2. lock all users and set their password to expired SQL> select ‘alter user ‘|| username || ‘ password expire account lock;’ from dba_users; 3. A locked user can only be accessed…

DataGridView控件 DataGridView是用于Windows Froms 2.0的新网格控件.它可以取代先前版本中DataGrid控件,它易于使用并高度可定制,支持很多我们的用户需要的特性. 关于本文档: 本文档不准备面面俱到地介绍DataGridView,而是着眼于深入地介绍一些技术点的高级特性. 本文档按逻辑分为5个章节,首先是结构和特性的概览,其次是内置的列/单元格类型的介绍,再次是数据操作相关的内容,然后是主要特性的综述,最后是最佳实践. 大部分章节含有一个“Q & A”部…

141. View the Exhibitand examine the structure of CUSTOMERS and GRADES tables. You need to displaynames and grades of customers who have the highest credit limit. Which two SQL statementswould accomplish the task? (Choose two.) A. SELECT custname,gra…

----转载:http://blog.csdn.net/xxfigo/article/details/6618129 定制模块行为(1) Option Explicit '强制对模块内所有变量进行声明    Option Private Module '标记模块为私有,仅对同一工程中其它模块有用,在宏对话框中不显示    Option Compare Text '字符串不区分大小写    Option Base 1 '指定数组的第一个下标为1(2) On Error Resume Next '忽…

1Columbia Universitycs3157 – Advanced ProgrammingSummer 2014, Lab #2, 60ish pointsJune 9, 2014Follow these step-by-step instructions. This lab must be submitted electronically by Monday June16th, 11:55 pm.The point of the labs is to teach and reinfor…

The easiest way to create a copy of a table is to use a Transact-SQL command. Use SELECT INTO to extract all the rows from an existing table into the new table. The new table must not exist already. The following example will copy the Customers table…

简介: sqoop是一款用于hadoop和关系型数据库之间数据导入导出的工具.你可以通过sqoop把数据从数据库(比如mysql,oracle)导入到hdfs中:也可以把数据从hdfs中导出到关系型数据库中.通过将sqoop的操作命令转化为Hadoop的MapReduce作业进行导入导出,(通常只涉及到Map任务)即sqoop生成的Job主要是并发运行MapTask实现数据并行传输以提升数据传送速度和效率,如果使用Shell脚本来实现多线程数据传送则存在很大的难度Sqoop2(sqoop1.99…