Database Administrator

Data Types in MySQL I. char and varchar types The char and varchar types are similar. They are used to store strings, but they are stored differently from the string retrieval method. Char is a fixed-length character type, and varchar is a

Setting a large memory page on Linux solves the problem that the kswapd0 process consumes cpusys in transition. Environment: SLES11 SP4 + Oracle 11.2.0.4After a new test database was set up and ran for about two days, it was found that a process

Master-slave database settings for Yii2 As the project grows, the master and slave databases are still indispensable. Using the Yii framework for development, how do I set the master and slave databases? It is actually very simple. First, modify the

Impact of the resource role on the quota of the quota tablespace Two days ago, I saw a brother in the Forum saying that the user set the table space's quota, but the data volume that exceeds the quota can still be inserted into the tablespace. I

ORA-12545: connection failed because the target host or object does not exist! ORA-12545: connection failed because the target host or object does not exist! The error occurs because the host name is incorrectly configured. Solution: 1. Search

How to query implicit Oracle Parameters Based on v $ parameter Oracle implicit parameters are not displayed in Oracle official documents. These parameters are mainly used in Oracle to control certain functions, or, as described by eygle today,

SparkSQL reads data in Hive Because Spark uses CDH of Cloudera and is automatically installed and deployed online. I recently learned SparkSQL and saw SparkSQL on HIVE. The following describes how to read HIVE data through SparkSQL. (Note: if you do

MySQL database instance Parameter comparison script How to compare the parameters of two MySQL instances is usually the requirement in production. Recently, a python script has been written to achieve this requirement. Script #!

Connect PHP to a MySQL database instance For those familiar with websites, if they want to make websites dynamic, they must have database support and use specific scripts to connect to the database, extracts resource H from the database, adds data

TimesTen reconstruction of the backup machine standard operation [TimesTen O & M] During TimesTen's O & M process, rebuilding the slave is the most frequently performed operation in daily O & M. Here we record the operation steps for rebuilding the

How to Use binlog to restore valid data after MySQL Data is lost Enable binlog, edit the my. cnf file, and add Log-bin = mysql-bin # enable the binary log and specify the path and file name, if not set, by default in the data storage directory, the

Oracle manual fixed SQL Execution Plan During the O & M process, we often encounter Oracle CBO selection rather than the expected execution plan due to changes in data and statistics of Oracle, the following is a record of the manual execution plan.

Summary of MySQL 5.7.11 compilation and installation and modification of the root password The system is CentOS 6.7 64-bit. By default, MySQL5.7.11 is downloaded to/usr/local/src. The installation directory is in the/app/local/mysql directory, mySQL

Install, configure and use phpRedis Install Redis before installing phpRedis. 1. Download and install On a Linux server, run the following command on the command line (the General source code of cd./usr local/src is put here (the installation of

MySQL explain Execution Plan OptimizationExplain execution plan Introduction to MySQL optimization: First discover the problem (slow query, profile) If indexes are used and no indexes are used, you can quickly find data by using indexes. What is

Common commands for viewing ASM disk Information 1.1 obtain disk Group Management Information1.1.1 view the disk pathSQL> selectname, path, group_number from v $ asm_disk_stat; 1.1.2 view disk group informationSQL> selectstate, name, type, total_mb,

Zabbix failed to monitor MySQL backup Environment: A: 172.16.16.1 (MySQL machine)B: 172.16.16.2 (backup machine)C: 172.16.16.3 (zabbix server) IntroductionAs A result of the company's development needs, we need to back up the Intranet Test Database

MySQL binlog secure deletion Introduction: If you have set up master-slave synchronization for MySQL or enabled log-bin for the database, a large number of log files will be generated in the data directory of your database over time. Shell>

Master-slave synchronization configuration of MySQL Databases in Linux Master-slave synchronization configuration of MySQL Databases in Linux 1. Configure the mysql master database #172.30.65.122 Mysql-u root-p # enter the Console Create database

Oracle idle wait events and non-idle wait events Oracle wait events are an important basis and indicator for measuring the operating status of Oracle. The concept of wait events is introduced in Oracle7.0.1.2, with approximately 100 wait events. In