Database Administrator

Introduction to Oracle High Water Mark (HWM) 1. What is high water level? High water level is the boundary between Oracle and unused space. It can also be understood as the boundary between data files and between non-data files, however, the data

Install and configure Redis on a Linux Server 1. Download and install redis 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 source code is recommended ))

Create a replica set on the MongoDB Cluster 1. Replica Set ConfigurationAfter successfully running MongoDB on a single machine, you need to disable the mongod daemon before using the replica set to create a Mongodb cluster: Mongod -- replSet setname

Understanding of B + tree and index in MySQLOverview Nature: Databases maintain certain data structures and reference (point to) data in some way Index selection principle: the structure of the index should minimize the number of disk I/O

Ubuntu 12.04 64-bit compilation and installation of MySQL 5.5.29 Step 1:Go to the official mysql website and go down to compile the source code package.Mysql Website: www.mysql.comDownloads (MySQL Community Server)Download the version, select source

Understanding of MySQL transaction commit and rollback errors I. Cause Begin or start transaction to START a TRANSACTION Rollback transaction rollbackCommit transaction validation The transaction is interpreted as follows: a transaction is composed

Install MySQL in Linux source code Today, in Ubuntu and CentOS, MySQL has been installed many times with the source code. Remember to write it down before you forget it. There is no difference in the installation process in Ubuntu and CentOS. 0.

MyCAT global serial number When database/table sharding is implemented, the auto-increment primary key of the database cannot be globally unique. Therefore, MyCat provides global sequence and multiple implementation methods including local

Snapshot standby features in Oracle 11g Among Oracle 11g, data guard is the most attractive. In addition to the Real-Time query feature of active data guard (you can open the physical standby database in read-only mode while the MRP process can

Application change deployment in production mode of Weblogic Scenario overview The next AdminSever in production mode allows WebLogic to manage multiple managedsevers. When deploying an application for the first time, you can select multiple

After MySQL 5.7 is installed in rpm mode in CentOS 7, root login cannot be used. Recently, the latest mysql-server 5.7 (mysql57-community-release-el7-7.noarch.rpm) version was installed in CentOS 7 using rpm, and root login was not available after

MySQL-Performance Optimization-about InnoDB buffer pool flush policies Background We know that InnoDB uses the buffer pool to cache data pages read from the disk to the memory. The buffer pool is usually composed of several memory blocks plus a

MySQL batch insert data script MySQL batch insert data script #! /Bin/bashI = 1;MAX_INSERT_ROW_COUNT = $1;While [$ I-le $ MAX_INSERT_ROW_COUNT]DoMysql-uroot-proot dbname-e "insert into tablename (name, age, createTime) values ('Hello $ I ', $ I % 9

Why does HBase need to build an SQL engine layer? The existing SQL solutions are generally not horizontally scalable, so when the data volume changes, it will encounter obstacles. However, with the emergence of NoSQL, it has been greatly mitigated,

MongoDB sharding simple instanceParts Another type of cluster exists in Mongodb, that is, the sharding technology, which can meet the needs of a large increase in MongoDB data volume. When MongoDB stores massive amounts of data, one machine may not

MySQL Tutorial: Build a MySQL Cluster in Linux Install fuse for mysql-cluster-gpl-7.4.6-linux-glibc2.5-i686.tar.gz (http://pan.baidu.com/s/1c1bjxVa) The system is a Linux virtual machine. 2 virtual machines (ensure that the firewall is disabled,

In CentOS Linux, MySQL databases are automatically backed up every day. In CentOS Linux, MySQL databases are automatically backed up every day. 1. Create the following three folders on the server: mkdir/bak, mkdir/bak/bakmysql, mkdir/bak/bakmysqlold.

Split Oracle data rows into multiple rows In work and study, we often encounter a situation where one row is divided into multiple rows of data. Here, we will make a comparison. Single Row splitting If the table has only one row of data, you can

MySQL SQL _mode Mode Modification my. cnf 1. SQL _mode ModeThe mysql database has an environment variable SQL _mode, which defines the SQL syntax and data verification that mysql should support! You can view the SQL _mode used by the current

Win remote ASM instance in Linux I. Windows ASM instances in remote Linux1. Listener files in Linux[Grid @ myrac1 admin] $ cat listener. ora# Listener. ora Network Configuration File:/g01/app/grid/product/11.2.0/grid/network/admin/listener. ora#