MySQL

1, the concept of the databaseThe database is the warehouse that holds the data, can conveniently put the data in, and take out the data according to various requirements.Database management System (databases Management System,dbms) is the database

650) this.width=650; "src=" http://s3.51cto.com/wyfs02/M02/6D/E4/wKioL1VutNigB7UhAAHj38-jZpc578.jpg "style=" float: none; "title=" 1.png "alt=" Wkiol1vutnigb7uhaahj38-jzpc578.jpg "/>650) this.width=650; "src="

BEGINSET @baseStr="SELECT * fromTbnameWHERE 1=1 ";SET @_where="";IF 1=1 Then 　　 SET @_where=CONCAT (@_where," andSourcedomain=\ "Www.baidu.com\" ");END IF;IF 2=2 Then 　　 SET @_where=CONCAT (@_where," andUserid=4444");END IF;SET @sentence =CONCAT

Start:Sudo/usr/local/mysql/support-files/mysql.server startStop it:Sudo/usr/local/mysql/support-files/mysql.server stopIt's still a bit trickier to simplify: add such a command to the ~/.bash_aliases:Alias mysqlstart= '

A mature database architecture is not designed to be high availability, high scalability and other features, it is with the increase in user volume, the infrastructure is gradually improved. The development cycle of the database is broadly divided

Last night on-line, but found a DDL statement has not been effective for a long timeCheck processlist, found numerous query hints including DDL statements "waiting for table metadata lock"The only query that does not have the hint is a full-table

Error:1)Change Master results in:Last_io_error:error Connecting to master-retry-time:60 retries2)To stop the slave process without unlocking:> Stop slave;ERROR 1192 (HY000): Can ' t execute the given command because you had active locked tables or

Resolve multiple Write Server Master self-growth ID duplication problemTwo MySQL servers, their IP addresses are:a:192.168.0.97b:192.168.0.98The databases are all test_3306.First, I'll post the My.ini for two servers.A:my.iniserver-id=2master-host=19

Transferred from: http://chenzhou123520.iteye.com/blog/1863407Introduction to optimistic Locking:Optimistic lock (optimistic Locking) relative pessimistic lock, optimistic locking hypothesis that the data generally do not cause conflict , so when

Environment Introduction:OS Version: RHEL5.5MySQL version: 5.5.40Reference Link: http://dev.mysql.com/doc/refman/5.5/en/time-zone-leap-seconds.htmlThere is a need: An attendance system, multiple APS distributed around the world, time must be in the 8

Implementation process:(1) Master changes the record to binary log (these are called binary log events, binary logs event);(2) Slave copies the binary log events of master to its trunk logs (relay log);(3) Slave redo the event in the trunk log and

I have long heard that the two commands, lock tables and unlock tables , literally know that the function of the former is to lock the table and the latter is to unlock it. But how to use, how to use, not very clear. Today, in a detailed study, we

MySQL Export DataIn MySQL you can use SELECT ... into OUTFILE statement to simply export the data to a text file. Use SELECT ... into OUTFILE statement to export dataIn the following example we export the data table TUTORIALS_TBL data to

Recently, their business to go online, after the launch, need to consider the various services to monitor, including (httpd services, mysqld services, etc.), now want to take mysqld services as an example to summarize the way the script is the most

MySQL ArchitectureConnection pooling Management tool SQL Interface Analyzer optimizer cache storage engine file systemWhat is a storage engineprocessors with different types of tables, different storage engines have different functions and storage

MySQL handles duplicate dataThere may be duplicate records in some MySQL data tables, and in some cases we allow duplicate data, but sometimes we also need to delete the duplicated data.In this section we will show you how to prevent data tables

MySQL Sequence UsageThe MySQL sequence is a set of integers: 1, 2, 3, ..., because a data table can only have one field self-increment primary key, if you want to implement other fields also automatically increase, you can use the MySQL sequence to

1, multiple threads at the same time modify the data, there is inconsistent data situation, that is, concurrency control problems. 2, MySQL provides read lock and write lock, read the lock can be read more lock, can not add write lock, and write

Bind hive to a local mysql database I suddenly wrote an article about changing the hive metadatabase from the default local derby to bind to a remote mysql database. I flipped through the cloud notes and found that it was actually true, share it

Use of MySQL triggersOverview: When a specific database event occurs in a specific table, the trigger executes the corresponding SQL command.Syntax: The General Command for creating a trigger is as follows: CREATE [temp | temporary] trigger