Learning notes for beginners of R language 7 - efficient grouping operation: dplyr
Note link
Learning notes 1-R language foundation. Study note 2 - Advanced Data Structures. Study note 3 - reading data in R language. Study note 4 - statistical chart. Learning note 5 - write R language functions and simple control loop statements. Learning Notes 6 - group operation.
Learning notes 7 - efficient grouping operation: dplyr ...
Posted by derekm on Wed, 20 Apr 2022 22:52:59 +0300
[MySQL core statement query] required for data analysts
This article data analyst must see! Last time I talked about the basics of database and mysql. This time, let's learn some of the most commonly used core query statements in MySQL.
The framed part is the focus of this section
1, Single table query
SELECT Field name FROM Table name WHERE condition [GROUP BY Field name HAVING condition ORDER ...
Posted by Jaspal on Wed, 20 Apr 2022 16:58:51 +0300
MapReduce core and basic routines
MapReduce core and basic routines
MapReduce is a programming framework for distributed computing programs and the core framework for users to develop "Hadoop based data analysis applications".
The core function of MapReduce is to integrate the business logic code written by the user and its own default components into a complete dis ...
Posted by farsighted on Tue, 19 Apr 2022 12:05:36 +0300
ActiveMQ learning 2 - integrating Spring
1. Broker for ActiveMQ
1. Introduction
(1) Overview
It is equivalent to an ActiveMQ server instance.
To put it bluntly, Broker actually implements the startup of ActiveMQ in the form of code, and embeds MQ into Java code so that it can be started at any time, and then when it is used, which can save resources and ensure availability.
2. St ...
Posted by Japet on Mon, 18 Apr 2022 17:29:12 +0300
[JAVA Road to God] operators and expressions
catalogue
1, Foreword
2, Logical operator
1. And
2. Or
3. Non
3, Ternary operator
4, Elementary bit operation
1. And
2. Or
3. Non
4. Same or
5. XOR
5, Shift operation
1. Move left
2. Move right
6, Priority
1, Foreword
Learning objective 1: be familiar with basic logical operators, ternary operators and calculationLearni ...
Posted by rajavel on Mon, 18 Apr 2022 04:44:58 +0300
Installing CM 6.3.1 and CDH 6.3.2
catalogueOperating system requirementsSoftware dependencyOperating systems supported by CDH and CMFile system requirementsnproc configurationConfigure nscd for KuduDatabase requirementsJava version requirementspreparationInstalling Centos 7Download package and planningCreate installation userConfigure domain name mappingConfigure SSH password f ...
Posted by vincente on Sun, 17 Apr 2022 23:07:33 +0300
Hadoop: API operation of HDFS
catalogue
0. Links to related articles
1. Client environment preparation
1.1. Installing hadoop environment in win10
1.2. Configure Hadoop environment variables
1.3. Create Maven project in IDEA
2. API case practice of HDFS
2.1. HDFS file upload (test parameter priority)
2.2. HDFS file download
2.3. Renaming and moving HDFS files
...
Posted by amites on Sun, 17 Apr 2022 17:52:48 +0300
YARN distributed resource manager
1, YARN (Distributed Resource Manager)
http://www.cnblogs.com/cxzdy/p/5494929.html
I) overall architecture of YARN
Yarn is Hadoop 2 X version proposes a new resource management architecture, which not only supports MapReduce computing, but also facilitates management, such as HBase, Spark, Storm, Tez/Impala and other applications. This new ...
Posted by brunosdiniz on Sat, 16 Apr 2022 15:04:03 +0300
HBase installation and configuration and common Shell commands
HBase installation and configuration
Step 1: unzip the HBase installation package
[root@master ~]# tar -zxvf /opt/software/hbase-1.2.1-bin.tar.gz -C /usr/local/src/
Step 2: Rename HBase installation folder
[root@master ~]# cd /usr/local/src/
[root@master src]# mv hbase-1.2.1 hbase
Step 3: add environment variables to all nodes
[root@mas ...
Posted by mrbuter on Fri, 15 Apr 2022 07:12:58 +0300
Comparison of Elasticsearch and Clickhouse basic queries
Elasticsearch is a real-time distributed search and analysis engine. Its bottom layer is built on Lucene. In short, Lucene has distributed functions by expanding its search capabilities. ES usually provides the function of end-to-end log / search analysis together with the other two open source components logstash (log collection) and Kibana (d ...
Posted by kmaid on Thu, 14 Apr 2022 22:59:57 +0300