Database Administrator

Usage of the count function in MySQL The count function is a function used to count records in tables or arrays. Here we will introduce the usage and Performance Comparison of the count function in MySQL. Count (*) returns the number of rows to be

Oracle Study-Oracle RAC reconstruction Control File System Environment:Operating System: AIX5.3 Cluster: Oracle 10gR2 CRSOracle: Oracle 10gR2 Rebuild the control file in the RAC environment is similar to that in a single instance, but note the

UPDATE of MySQL lock Learning I have been learning MySQL for quite a long time and can stay in a state where I can work but I am not proficient. In addition, many MySQL knowledge points are affected by SQL Server's understanding bias. I can only

MySQL database Optimization How should we optimize the MySQL database? Next I will explain this problem from MySQL's hardware selection, MySQL installation, my. cnf optimization, MySQL architecture design, and data splitting. Optimization of server

Jdbc connection string for Oracle pluggable Databases When I deploy a database of a third-party system on the server, the server database version is Oracle 12c. I created an instance. Access is normal. Later, the project owner told me that Oracle 1

Oracle 11g + RAC + RHEL6.5 + udev + ASM + PSU Installation Summary 1. Preparations before installation: Operating System: RHEL6.5 Storage: Huawei, multi-path configured Bind the business network card and heartbeat network card and pass the

Compare two columns of data in an Excel table to find the similarities and differences. There are two columns of Data A and B in Excel. Check whether the data in B exists in A and the result is displayed:   1: Add "=" in [1], and a function will

How to install PostgreSQL 9.6 In CentOS 7: centospostgresql Preface PostgreSQL is a powerful open-source object relational database system that runs on almost all major operating systems, including Linux, Unix (AIX, BSD, HP-UX, sgi irix, Mac OS,

Commonly used time and date scripts in PostgreSQL tutorial, postgresql tutorial Obtain System Time Functions select now(); --2013-11-28 16:20:25.259715+08select current_timestamp; --2013-11-28 16:20:38.815466+08select current_date; --2013

Application scenarios of several Redis data structures and redis data structure scenariosString[Html]View plaincopy 1. String Common commands: In addition to get, set, incr, decr mget, and other operations, Redis also provides the following

Mysql data backup and recovery, User Creation, authorization, mysql backup and recovery Mysql data backup and recovery, User Creation, authorization 1. Mysqldump> outfile. SQL 2. Mysql-uxxx-pxxx 3. Create user 'username' @ 'host' identified by '

Mysql administrator password retrieval, mysql administrator passwordWe may forget the ROOT password for various reasons when using MYSQL. If so, the database may be discarded, however, I would like to share with you today how to retrieve the ROOT

MongoDB: gradually becoming irrelevant, and mongodb is irrelevantAbstract:Compared with TokuMX and PostgreSQL, MongoDB is at a disadvantage. However, it is still a good product and will continue to improve to compete with these alternative products.

Oracle442 application scenarios --------- physical structure of Oracle Database, oracle Database Application   ------------------------- Physical structure of Oracle Database ------------------------------- Physical Structure of Oracle

Symantec NetBackup 7.6 (NBU) FAQ, netbackupnbuSymantec NetBackup 7.6 Product Licensing Overview Product Name: Symantec NetBackup Product Version: 7.6 Release Date: 2013-12-18 Product OverviewProduct OverviewNetBackup with V-Ray technology is the

Discuss Seconds_Behind_Master again, and discuss the master to clean up the aftermathI wrote an article two years ago to explain the meaning of Seconds_Behind_Master and why it is inaccurate. Today, my colleague Gao asked another interesting

Install and uninstall Mysql in Mysql source code mode, and uninstall mysql in Mysql source code mode1. Introduction to Basic Environment 1.1 Software Environment Operating System: redhat linux 6.3 Mysql version: Mysql 5.6.241.2 disk directory

Based on data analysis, whether automatic vehicles consume more oil than manual vehicles, and automatic data analysisOverview This is a multivariate regression equation used to reveal the relationship between vehicle fuel consumption and vehicle

Comparison of Oracle, mysql, sqlserver, and postgresql statements, postgresql and oracle 1. Paging Oracle:SELECT * FROM (select a. *, rownum rn from (select T. * from sj_receiptinfo t WHERE t. taxno like concat ('%', CONCAT (?, '%') Order by t. id

Database System check before holidays and database check before holidays This article is the original article, reproduced please indicate the source: http://blog.csdn.net/msdnchina/article/details/43761361 1. If the Operating System Log reports an