Database Administrator

MariaDB beginner management commands Earlier, we learned to install the MariaDB server on CentOS/RHEL 7 (SEE), which is now the default database of RHEL/CentOS 7. Now we will discuss some useful MariaDB management commands. These are some very basic

MySQL master database High Availability-Dual-master single-active failover Solution Preface: (PS: Preface was added later when this article was modified.) Some bloggers raised some questions and opinions about this article and paid attention to it,

TABLE_EXISTS_ACTION parameter option of impdp Impdp has a parameter option TABLE_EXISTS_ACTION. The help = y is interpreted: Action to take if imported object already exists.Valid keywords are: APPEND, REPLACE, [SKIP] and TRUNCATE. There is a

Configure the OCI environment in Linux Oracle Call Interface (OCI) provides a set of Interface subroutines (functions) that can be accessed to Oracle databases) to access the Oracle database. Required environment and software: Automake: automake 1.11

Installing MySQL 5.6.10 package conflict in Linux By default, the Liunx operating system will install lib files such as mysql-libs-5.1.73-5.el6_6.x86_64, which will conflict with the installation file of MySQL5.6.10, the first installation is as

Oracle 10g rac ip/VIP address modification exampleI. Preparations 1. Database Information Operating system version: OEL5.4 x64Database Version: Oracle 10.2.0.5 x64 RAC2. IP address information Note: The server host name cannot be changed. If you

MRP0-Background Media Recovery terminated with error 1111 Due to the improper configuration of db_file_name_convert, the data file cannot be automatically synchronized to the standby database for troubleshooting.Check Master/Slave log

Set the MySQL character set to utf8 in Ubuntu Set the MySQL character set to utf8 in Ubuntu 1. mysql configuration file address/Etc/mysql/my. cnf 2. Add the following code below [mysqld][Mysqld]Init_connect = 'set collation_connection = utf8_unicode_

12 tips for easy survival in Apache Hive Learn to live with Apache Hive in 12 easy steps Hive allows you to use SQL on Hadoop, but optimizing SQL on a distributed system is different. Here are 12 tips that allow you to easily master Hive. Hive is

Install MySQL + Security optimization with apt-get on Ubuntu 0. Description The advantage of using apt-get for installation is that you don't have to solve the dependency problem between software by yourself. Basically, after apt is executed, the

MySQL string truncation Functions In work, some fields may need to form a string by a separator as the field value to access the database table. For example, a task pair should store three results in different data tables, in this case, the primary

How to install MySQL Server in CentOS 7 Previously, RHEL 6.3 and 6.4 were used. The system disk contains the mysql server. After configuring the yum source, you can directly install mysql-server on the yum install mysql server. Recently, CentOS 7.1

Global Database ranking in December: PostgreSQL steadily increases and postgresql steadily increases Author: Zhou Qi DB-Engines released the database ranking for January. Among the top 20 databases, Oracle ranked first, with Cassandra ranking 9th

Use ESCAPE to define escape characters in SQL. Use ESCAPE to define ESCAPE characters When the LIKE keyword is used for fuzzy search, "%", "_", and "[]" appear separately, and are considered as wildcards. To check whether there are percent (%),

Install PostgreSQL and centos7postgresql on CentOS7 Install the postgresql Software Package sudo yum install postgresql-server postgresql Initialize db sudo su - postgresinitdb -D /var/lib/pgsql/data Start/stop a service systemctl status

[C3p0] Article 2: Using c3p0,Preface According to the c3p0-0.9.5.1 version of the official documents, coupled with their own understanding, compiled into the translation. Limited capabilities. If the translation content is incorrect or your

Oracle (zero) --> pseudo-column and group aggregation (starting from Oracle, relatively beginner ~), OracleIn the beginning ~It's time to start school .. What does it have to do with me ..), After all, I took up my job even though I didn't know what

Sort by salary in descending order. If the salary is the same, sort by employment date. 6 ~ 10 records, required Example: sort by salary in descending order. If the salary is the same, sort by employment date. Get 6 ~ 10 records 1. Obtain the

[Java] itoo project practices: optimized collection of millions of data queries and itoo data queries 1. To optimize the query, you should consider creating an index on the columns involved in where and order.   2. Try to avoid null value

Ora-01445: unable to select ROWID or sampling from the join view of a table without reserved keywords, ora-01445rowid When you query a view today, the query contains the rowid field, and an error is returned:     Two simple table tests: