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Mysql Management Operations Database management operations View database structure Create and delete libraries and tables Manage records for tables Basic Operational Commands View database list information SHOW DATABASES [root@localhost ~]# mysql -u root -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your ...

1. hbase integration Mapreduce    in the offline task scenario, MapReduce accesses HBASE data to speed up analysis and expand analysis capabilities.Read data from hbase (result) public class ReadHBaseDataMR { private static final String ZK_KEY = "hbase.zookeeper.quorum"; private static final String ZK_VALUE = "hadoop01:2181,h ...

1) install Mysql database [root@localhost ~]# rpm -q mysql mysql-server Package mysql is not installed Package MySQL server is not installed [root@localhost ~]# yum -y install ncurses-devel [root@localhost ~]# rpm -q ncurses-devel ncurses-devel-5.9-14.20130511.el7_4.x86_64 Install configuration tool cmake [root@localhost ~]# tar xf cmak ...

Catalog MySQL highly available Galera Cluster Galera Cluster Galera Cluster features Disadvantages of Galera Cluster Galera Cluster working process Official document of Galera Cluster Galera Cluster consists of two components WSREP replication implementation PXC princ ...

python chain home asynchronous IO crawler, using asyncio, aiohttp and aiomysql Many small partners will learn about crawlers when they start to learn python. When they start to learn python, they will use requests and urlib synchronous libraries for single thread crawlers, which is slow. Later, they will use the scratch framework for crawlers, ...

1. Environment: centos7.5 MySQL 5.7192.168.3.222 master192.168.3.158 slave192.168.3.223 VIPTwo: first, make two mastersTo operate both machines2.1: domain name resolution: ###vim /etc/hosts (both) 192.168.3.222 master 192.168.3.158 slave 2.2: Download MySQL 5.7 ### wget http://repo.mysql.com/mysql57-community-release-el7-8.noarch.rpm ### rpm - ...

1.1 smallint description 1.2 smallint practice 1.2.1 environmental preparation 1.2.2 plus UNSIGNED parameter 1.2.3 plus ZEROFILL parameter 1.2.4 without UNSIGNED and ZEROFILL parameters 1.3 summary of smallint 1.1 smallint description type length Length is when length is not specified Occupying byte Signed Unsigned smallint 5 6 (actual l ...

Environmental Science mysql-5.7.19 Centos7 master: 192.168.111.64 slave: 192.168.111.66 Master slave configuration master configuration ## GTID server_id = 100 # Server id. the slave database should be larger than the master database, and be unique gtid_mode = on #Turn on gtid mode enforce_gtid_consistency = on #Force gtid consistency. ...

Hadoop 2.x.y (pseudo distributed) Refer to the single node setup section of the corresponding version of the official websitehttps://hadoop.apache.org/docs/ First, ssh and rsync Then download the bin package and extract it. Add the extracted root directory as the environment variable Hadoop? Home # example export HADOOP_HOME=/home/yzj/Applicat ...

What is ORM? Simply speaking, it is the encapsulation of SQL query statements, which enables us to operate the database in the OOP way and generate safe and maintainable SQL code gracefully. Intuitively, it is a mapping relationship between Model and SQL. sequelize.query (original query) By default, the function returns two parameters - an ar ...