[1] set a password for the root user of MySQL
When MySQL was just installed, its root user was not set a password. First, set the MySQL Root Password.
[Root @ sample ~] # Mysql-u root login use the root user to log on to the MySQL server
Welcome to the MySQL monitor. commands end with; or \ G.Your MySQL connection ID is 2 to server version: 4.1.20
Type 'help; 'or' \ H' for help. Type '\ C' to clear the buffer.
Mysql> Select User, host, password from mysql. User; login view user information+ ---
itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show variables like '%log';
+--------------------------------+-------+| Variable_name | Value |+--------------------------------+-------+| back_log | 50 || general_log | OFF || innodb_locks_unsafe_for_binlog | OFF || log | OFF || relay_log | || slow_query_log | OFF || sy
Friends familiar with Oracle know that when the Oracle database does not start properly, you can save data and reduce loss by dul or other tripartite tools that directly read data from data files. If you use the InnoDB engine in MySQL, you can also extract related records when the MySQL database does not start. To extract the data dictionary chapter, the following will continue to provide the drop recovery, truncate recovery, delete recovery and other MySQL unconventional recovery chapters.
Cre
password 2: Cross the Authorization librarySlightlySQL statementsSQL statements: Structured statements, SQL is a set of operational commands created specifically for the database, and is a fully functional database language. Almost all relational databases have support for SQL statementsSQL Statement Specification:1, case-insensitive (the command suggests capitalization, because during SQL parsing, the database automatically converts lowercase commands to uppercase, and when there is a large nu
database.1 mysql> use test2 Database changed3 mysql> show tables;4 Empty Set (0.00 sec) 5 6 mysql> CREATE TABLE Checknull (7 - name varchar (9) Not null,8-age int); 0 rows affected (0.11 sec)Let's look at the basic information for creating this table, with show and DESC separately: 1 mysql> show create TABLE checknull; 2 +-----------+-----------------------------------------------------------------
MySQL User management and transactionsAfter learning the installation and basic operation of MySQL on CentOS7, we will learn about MySQL user management and business. First of all, a database is not only one user, when creating a good database, we only have a default root user, how to create a new user? OK, let's study together!
First log in to the MySQL database using the root user[[emailprotected] ~]# mysql -u root -pEnter password: //输入root的密码:abc123mysql> //然后就可以看到进入MySQL数
)---------------------------------------------------------------------......COMPRESSION Reduce size of dumpfile contents where validKeyword values are: (METADATA_ONLY) and NONE.......The COMPRESSION parameter in 10 Gb only provides the METADATA_ONLY and NONE options, and basically does not provide the COMPRESSION function.
3. Use the four Compression Parameters of the 11g EXPDP tool to generate four dump files respectively.1) Use the ALL ParameterSecooler @ secDB/expdp $ expdp
the statement throws an exception; ROLLBACK to Identifier: Roll the transaction back to the Mark Point; Set TRANSACTION: Used to set the isolation level of a transaction. The InnoDB storage engine provides transaction isolation levels of READ UNCOMMITTED, read COMMITTED, Repeatable read, and serializable.There are two main methods of MYSQL transaction processing:1, with BEGIN, ROLLBACK, commit to achieve Begin a transaction ROLLBACK transaction Rollback Commit TRANSACTION Acknowledgement 2, dir
Original: SQL Server needs to monitor which countersGeneral countersCollects server performance information for operating system servers, including processor, disk, network, memoryProcessor Processor1.1% Processor time refers to the percentage that the processor uses to perform non-idle threads. This counter allows you to determine the current percentage of CPU usage for the server.1.2% Privileged is the percentage of time that the process thread spends executing code in privileged mode. When Wi
General countersCollects server performance information for operating system servers, including processor, disk, network, memoryProcessor Processor1.1% Processor time refers to the percentage that the processor uses to perform non-idle threads. This counter allows you to determine the current percentage of CPU usage for the server. 1.2% Privileged is the percentage of time that the process thread spends executing code in privileged mode. When Windows system Services is invoked, this service ofte
Label:General countersCollects server performance information for operating system servers, including processor, disk, network, memory Processor Processor 1.1% Processor time refers to the percentage that the processor uses to perform non-idle threads. This counter allows you to determine the current percentage of CPU usage for the server. 1.2% Privileged is the percentage of time that the process thread spends executing code in privileged mode. When Windows system Services is invoked, this serv
Mysql database learning notes common operation commands 1. create a database www.2cto.com mysql> create database user; Query OK, 1 row affected (0.00 sec) 2. use this database mysql> use user; database changed3. create a table mysql> create table person (-> id int unsigned not null auto_increment primary key,-> name varchar (30)->) on this Database; Query OK, 0 rows affected (0.00 sec) 4. view the table str
large and both are moderate, the hard Disk may be a bottleneck. Before recording this counter, run diskperf-yD in the command line window of Windows 2000. If the value exceeds 80%, the memory may leak.
Availiable bytes (memory): number of physical memories used. If the Available Mbytes value is small (4 MB or smaller), it indicates that the total memory on the computer may be insufficient or a program has not released the memory.
Context switch/sec (
chapter for extracting data dictionaries. We will continue to provide the following chapters for non-conventional mysql recovery, such as drop recovery, truncate recovery, and delete recovery.Create a get_dict test table
mysql> use xifenfei;Reading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -ADatabase changedmysql> show tables;+--------------------+| Tables_in_xifenfei |+--------------------+| t_delete |+------
Mysql database learning notes-common operation commands bitsCN.com
Mysql database learning notes-common Operation Commands
1. create a database
Mysql> create database user;
Query OK, 1 row affected (0.00 sec)
2. use this database
Mysql> use user;
Database changed
3. create a table in this database
Mysql> create table person (
-> Id int unsigned not null auto_increment primary key,
-> Name varchar (30)
-> );
Query OK, 0 rows affected (0.00
counters are as follows:
Sqlperfdata Receiving counter Information
Displaytoid: Counter automatically generated, record counter start informationCounterdetails: Counter is generated automatically, record the basic information of counterCounterdata: Record counter incoming data??
Sqlperfdatastat Statistics Counter Information
Basic Information module:Counterdetails_collect: Used to synchronize counterdetails table data for rotation statisticsCounterdetails_collect_bak
1. Database management1.1 CREATE DatabaseCreate Database Firstdb;1.2 Show view all databasesmysql> show databases;+--------------------+| Database |+--------------------+| Information_schema || Firstdb || MySQL || Performance_schema |+--------------------+4 rows in Set (0.00 sec)1.3 Alter modifies the databaseThe ALTER command modifies the database encoding:The default database created by default does not support Chinese characters, and if we need it
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