mysql myisam

Official accurate explanation · MyISAM: the default MySQL plug-in storage engine, which is one of the most commonly used storage engines in Web, data warehousing, and other application environments. Note: by changing the storage_engine configuration variables, you can easily change the default storage engine of the MySQL server. · InnoDB: used for transaction p

Label:As a Java web Developer, the differences between the two types of engines are quite good for MySQL databases, and the following is an introduction to the understanding of the two types of engines I've accumulated at work. MyISAM: If you do not change the MySQL configuration file (My.ini), MyISAM is the default st

Will MySQL's storage engine, if MyIsam, be modified to InnoDB, will it result in data loss, or other exceptions? Reply content: Will MySQL's storage engine, if MyIsam, be modified to InnoDB, will it result in data loss, or other exceptions? Does not result in data loss, an important difference between InnoDB and MyISAM is that the former supports transact

For detailed explanations and examples, see the followingArticle: Http://www.mysqlperformanceblog.com/2008/09/03/analyze-myisam-vs-innodb/Http://www.penglixun.com/work/database/mysql_show_index_cardinality.html (1) cardinality affects the selection of indexes by MySQL Optimizer (2) You can use show index from table_name to view the table index and cardinality. (3) differences between cardinality in In

Today, we will share with you the differences between the actual application of InnoDB and MyISAM In the MySQL storage engine, as well as the differences in related functions and their advantages and disadvantages, if you are interested, you can click the following articles to view them. Explain the differences between "InnoDB" and "MyISAM" InnoDB and

Tags: data storage example Maintenance www ack cannot inno multi-version defaultDatabase, MySQL such as the existence of multi-storage engine database software, clear common storage engine differences, using the appropriate storage engine, make the project run smoother, sometimes for a project, even more important than the project itself. This article aims to talk about the differences between common three kinds of storage engines, pros and cons. It i

Algorithm Implementation of this calculator, see AUTO_INCREMENTColumn inInnoDBHow to work The number of rows in the table. Select count (*) from table, MyISAM simply reads the number of rows saved. Note that when the count (*) statement contains the where condition, the operations of the two tables are the same. InnoDB does not store the specific number of rows in the table. That is to say, when you execute select count (

operations when the isolation level is repeatable READ: SELECT InnoDB must have each row of data to ensure that it complies with two conditions: 1, InnoDB must find a version of the line, at least as old as the version of the transaction ( That is, its version number is not greater than the version number of the transaction. 　　This ensures that the data is present either before the transaction starts, or when the transaction is created, or when the row data is modified. 2. The deleted version o

Concurrency Control) multi-version concurrency controlsInnoDB: Implement MVCC by adding two additional hidden values for each row of records, one to record when this row of data was created, and another to record when this row of data expires (or is deleted). However, InnoDB does not store the actual time at which these events occur, but instead only stores the system version number when these events occur. This is a growing number of transactions as they are created. Each transaction will reco

ArticleDirectory 1. mysqldump 2. mysqlhotcopy 3. SQL syntax backup 4. Enable BINLOG) 5. Back up data files directly 6. Backup Policy 7. Data Maintenance and disaster recovery This article discusses the MySQL backup and recovery mechanisms and how to maintain data tables, including the two most important table types:MyISAMAndInnoDBThe MySQL version is 5.0.22. Currently,

Tags: mysql myisamchk"Repair MyISAM table error after MySQL power off restart" fix_myisam_table.sh#!/bin/bash# # 2014/10/13fix_bin= '/usr/bin/myisamchk ' d_db_data= '/data/mysql_data/3306 ' dt= ' date + '%y%m%d ' ' CD ${d_db _data}echo ' >>=========================== ' tail ' hostname '. Err-n |grep $dt |grep "Checking table" |awk ' {print $NF} ' echo '----------

a federated index with other fieldsBetter and faster auto_increment processing If you specify auto_ for a table Increment column, the InnoDB table handle in the data dictionary contains a counter called the autogrow counter, which is used to assign a new value to the column. auto_increment innodb auto_increment select count (*) from Table,myisam simply read out the number of rows saved, and note that when the

Mysql unique option prefix myisam_recover instead of myisam-recover-options solution, myisamrecover The literal meaning is to write all the parameters. This statement is not supported in later versions. Many materials provided on the Internet can be repaired using myisam_recover directly, but parameters must be added in the new version. Originally: Copy codeThe Code is as follows:Myisam_recover Now: Copy co

MyIsam is relatively simple to publish, just copy all the files in the library. The procedure of copying Innodb is similar to that of MyIsam, except that the table content in the Innodb Engine no longer exists in the same database directory (MyIsam does this). In the Innodb engine, data files are stored in files such as ibdata1, and operation logs are stored in f

MySQL 5.1 Upgrade compile install 5.6 Convert the original MyISAM table to InnoDB and back up the global one at a time1."Backup specified database" Do not use commas mydb hellodb[Email protected] ~]# mysqldump-uroot-p--databases mydb hellodb >/tmp/all.sql"Modify Engine=myisam to Engine=innodb"[[email protected] home]# CP hellodb.sql hellodb.sql.bak[[email protect

Recently, due to the increase in database read requests, there was a serious read/write lock problem. Due to Master/Slave separation, the master server quickly completed the write operation, however, a large number of select queries in the slave database will be severely blocked by the update and insert statements synchronized from the master database and the slave database, resulting in a rapid increase in the load of all Mysql databases. Recently, d

The similarities and differences between MyISAM and InnoDB: InnoDB and MyISAM are the two most commonly used table types in MySQL. their respective advantages and disadvantages depend on the specific application. The basic difference is that the MyISAM type does not support advanced processing such as transaction proce

Tags: Create database Type=myisamType=myisam behind the Create statementBoth Type=myisam and Engine=myisam are statements that set up the database storage engine (older versions of MySQL use type instead of engine (for example, type = MyISAM).

There is a MySQL database with more than 1.1 billion records because of its working relationship. I thought that the query performance of the MyISAM engine would exceed InnoDB. I tried it these two days, There is a MySQL database with more than 1.1 billion records because of its working relationship. I thought that the query performance of the

I have a table that is relatively large, so I made a sub-table. the main table has an auto-increment id and some main attributes, and the sub-table has a longtext field (10 in one sub-table ), when adding a primary table record, I need to obtain the auto-incremental id value to add the corresponding data to the table. I know innodb can use events to do this, but for many reasons, I cannot change myisam to innodb, so I would like to ask experienced exp