Database Administrator

Simple Steps for migrating from MySQL to MariaDB on Linux Hello everyone! This is a tutorial on how to migrate from MySQL to MariaDB on a server or PC. You may ask why we want to migrate database management from MySQL to MariaDB. Let's look at why

(6) Character Set in mysql, Character Set in mysqlOverview In essence, a computer only recognizes binary code. Therefore, no matter the computer program or the data it processes, it must eventually be converted to binary code before the computer

Mysql Master Slave Config, mysqlslave Install two or more MySQL services on the same machine: Download the mysql installation package. After the installation is complete, copy multiple copies of the installation folder on the disk. Enter my. ini

'Root' has exceeded the 'max _ questions 'resource (current value: 100) (1226), qtresourceroot Colleague encountered a problem Mysqldump: Couldn't execute 'select @ collation_database ': User 'root' has exceeded the 'max _ questions' resource

Database optimization tutorial (8) under what circumstances should indexes be used and indexes be optimized?Iii. Index 5. Under what circumstances should indexes be used? Since the index has a cost, you should not use it without using the

Database Tuning tutorial (9) index TuningIii. Index 6. Several Common possibilities of indexing but not being used I talked about when to avoid using indexes, but sometimes I don't know how to use indexes. Below are several cases where indexes

Examples of importing and exporting Oracle databases in common/Data Pump Mode in Windows/Linux environments, oraclelinux1 Linux normal export/import1.1 terminal ExportExp naricom/naricom@10.185.3.100/SGTMS owner = '('MW _ app, mw_sys, statdba,

SQL summarizes the record results by day and supports pagination. No records are filled with 0 values. SQL is collected by day. The format in the database is as follows. It is a record list, which must be output in descending order of daily summary.

Mybatis, mybatis 1. Introduction to MyBatis MyBatis is an excellent persistent layer framework that supports common SQL queries, stored procedures, and advanced mappings. MyBatis eliminates the manual setup of almost all JDBC code and parameters and

Spring integrates Mybatis and springmybatis Jar file: http://download.csdn.net/detail/huhui_bj/8575533 1. Prepare the jar package [Mybatis]Mybatis-3.2.0.jarMybatis-spring-1.1.1.jarLog4j-1.2.17.jar[Spring]Spring-aop-3.2.0.RELEASE.jarSpring-beans-3.2.

Database optimization tutorial (7) cost and cost of INDEX OPTIMIZATIONIii. Index 4. index costThe previous sections introduced the power of indexes in improving performance and how to use indexes. However, indexes also have overhead. 1) disk space

Common SQL statements 1. query data table names, fields, and field descriptions SELECT t. [name] AS table name, c. [name] AS field name, cast (ep. [value] as nvarchar (200) AS [field description] FROM sys. tables AS t inner join sys. columns AS

Database optimization tutorial (6) index-related operations, tuning IndexesIii. Index 3. Index-related operations In the previous section, we introduced the functions and types of indexes. This section describes the operations related to indexes! 1)

SQL Server data encryption and decryption: create the same symmetric key in multiple server instances (3). SQL server encryption and decryption It is very easy to create the same symmetric key. Symmetric keys created using the same KEY_SOURCE,

In Oracle, how does a function return a result set? In Oracle, function return result sets are sometimes used. The following is a demo: Create or replace type t_test as object(Id integer,Create_time date,Object_name varchar2 (60));Create or replace

Analysis of several cases where the Mysql index fails. During the project process, it is inevitable that an index is created for mysql, but the query is still very slow, next we will analyze the causes and solutions for this situation: Indexes

Install the initial configuration of MongoDB in Win7, win7mongodb 1. Download www.mongodb.org Ii. Installation Decompress the package to a directory without spaces. My directory is D: \ Program Files \ MongoDB \ After Windows starts, right-click

Mysql: command not found, mysqlfoundThis problem is often encountered after mysql is compiled and installed.The root cause is that the mysql command is not loaded into the current user's environment variable.Solution # Find/-name mysql

How to solve the problem of slow and fast Association of temporary tables in the Stored Procedure When a stored procedure is called, the database load is normal under the same conditions, and the time is fast and slow. The reason is that the

Unused database indexes found To ensure quick access to data, like other relational database systems, SQL Server uses indexes to quickly search for data, SQL Server can create different types of indexes, such as clustered index, non-clustered index,