index directory

The index cache is actually something that exists to optimize the vertex cache and can save memory consumption. It is understood that the combination of the index cache with the vertex cache will be much faster. Index caches and vertex caches are

1. Avoid null for field value, give default value as far as possible, integer: 0, decimal: 0, Character: 'Null values cannot be indexed, index is not enabled when querying null values, full table scan(a null value is still required in the table for

Objective Unlike most databases, MySQL has the concept of a storage engine that can choose the optimal storage engine for different storage requirements. 1. MySQL Storage Engine Overview Plug-in storage engine is one of the

Action object: Database1) Create a databaseMariaDB [(None)]> help CREATE DatabaseName: ' CREATE DATABASE 'Description:Syntax:CREATE {DATABASE | SCHEMA} [IF not EXISTS] Db_name[Create_specification] ...Create_specification:[DEFAULT] CHARACTER Set [=]

In the construction of the whole WAMP environment, the essential work is as follows:1, the configuration system to PHP DLL files can be called by default.Under WinDOS, there are two ways to use the DLL file system by default in the calling state.The

Connect and DisconnectConnectionMysql-h Host-u User-p (that is, the connected host, user name, and password used).DisconnectEnter quit (or \q) to exit at any time:Table ManagementClone tableNote: The CREATE TABLE ... like statement does not clone

(Backup restore operation) # # #导出数据库/usr/bin/mysqldump-u root-pwd Database > database20180808.sql## #导入数据库mysql-u root-p Database Extract database20180808.sql.gz### Compressed files from gzip $backupdir/database$time.sql.gz        #        find $

| Story Background The workplace is like a battlefield! Sum led three small teammates for two weeks, successfully the agent function to dry out. If the product manager is the Devil's commander, the test is the Devil's instructor. This two weeks,

This time we are going to explore finer binlog content, and the last discussion of Query_event and Rows_event certainly has questions that make you puzzled. What are the Status-vars environment variables in query_event, what are the data types of

MyISAM Storage EngineOriginal http://www.cnblogs.com/villion/archive/2009/07/09/1893762.htmlMyISAM is the default storage engine. It is based on older ISAM code, but there are many useful extensions. Some features of the MyISAM storage engine:· All

Oracle 10g RAC Installer failure--oracle Software Installation Unable to discover the clusterSystem environment:Operating system: AIX 5300-08Cluster Software: CRS 10.2.0.1Database: Oracle 10.2.0.1First, the phenomenon of fault650) this.width=650;

The "IT168 technology" Sql_mode may be a variable that is easier for developers and DBAs to ignore, and is empty by default. The Sql_mode setting is actually a more risky setting because it allows for some illegal operations, such as inserting null

To find the storage engine for a database:Show enginesShow variables like '%storage_engine% 'Change the engine of the database to change the configuration file/etc/my.cnfModify Default-storage-engine=innodb (the storage engine that needs to be

1. Background* in MySQL, create a data table, in its data directory corresponding to the database directory has a corresponding table of. frm files,. frm files are used to hold each data table metadata (meta) information, including the definition of

Sql_mode may be a variable that is easier for developers and DBAs to ignore, and is empty by default. The Sql_mode setting is actually a more risky setting because it allows for some illegal operations, such as inserting null into a NOT null field,

SQL Server ModeMySQL servers can operate in different SQL modes, and different modes can be applied to different clients. This allows each application to customize the operating mode of the server according to its own needs.The schema defines which

Tuning Ideas: 1. Database design and planning-it's a hassle to fix it later, estimate the amount of data, what storage engine to use 2. Application of data--how to fetch data, optimization of SQL statements 3.mysql Service

One, sed (Stream EDitor) 1. Introduction to SED definition : The stream editor, which handles rows, also known as the row editor. Two spaces are exposed to the process, one is pattern space and the other is space-preserving pattern Space :

Chattr: Setting Special PermissionsLsattr: Viewing Special permissionschattr [+-=] [asacdistu] [file or directory name]Parameter description:+-=: "+" (increment), "-" (decrease), "=" (set) property, respectivelyA: When the property A is set, the

Rpm We know that the programs that are used on top of the operating system are developed by programmers through development tools, and the plain text written by programmers is what we call source code. Because computers only know the binary,