Mysql physical file Composition

Mysql physical file composition 1.1 Log File 1) Error Log: Error Log records all serious warnings and Error messages during MyQL Server running, as well as detailed information about each start and close of MySQLServer. By default, the system records error logs. www.2cto.com 2) Binary Log: Binary Log & Binary Log Index name] "after the record function is enabled, MySQL records all queries that modify Database Data in Binary form to the Log file. Of course, the log is not only as simple as the query statement, but also includes the time, resources, and related transaction information of each query execution. Therefore, binlog is transaction-safe.
3) update log: update log 4) query log: query log 5) slow query log: slow query log 6) Innodb online redo log: innodb redo log Innodb is a transaction-safe storage engine. Its transaction security is mainly ensured by the online redo log and the undo information recorded in the tablespace. The redo log records all the physical changes and transaction information of Innodb. Innodb ensures transaction security under any conditions through the redo log and undo information. 2.2 data files in MySQL each database will have a folder named after www.2cto.com under the defined (or default) data directory to store various table data files in the database.
1. ". frm" File
Metadata information related to tables is stored in the ". frm" file, including the definition information of the table structure. No matter what storage engine, each table will have a ". frm" file named after the table name. 2. ". MYD" File
The ". MYD" file is dedicated to the MyISAM storage engine and stores data in the MyISAM table. Each MyISAM table corresponds to a ". MYD" file, which is also stored in the folder of the database to which it belongs and is stored together with the ". frm" file.
3. The ". MYI" File ". MYI" is also dedicated to the MyISAM storage engine and mainly stores the index information of the MyISAM table. Www.2cto.com
4. ". ibd files and ibdata files are files that store Innodb data. They are used to store Innodb data (including indexes ), the reason is that the Innodb data storage method can be configured to decide whether to use the shared tablespace to store the stored data or the exclusive tablespace to store the stored data. Author: Chen jianhong