Practical application and functions of MySQL backup _ MySQL

The following articles describe the practical application and functions of MySQL backup. they mainly describe the actual application and related functions of MySQL backup, and how to correctly maintain data tables, there are also two common table types, namely MyISAM and Innodb. the MySQL version is 5.0.22.

Currently, MySQL supports the following free BACKUP tools: MySQLdump and MySQLhotcopy. you can also use SQL syntax to back up: BACKUP TABLE or SELECT INTO OUTFILE, or back up binary logs (binlog ), you can also directly copy data files and related configuration files.

MyISAM tables are saved as files, so they are relatively easy to back up. the methods mentioned above can be used. All Innodb tables are stored in the same data file ibdata1 (multiple files or independent tablespace files), which is relatively difficult for MySQL backup, the free solution can be copying data files, backing up binlogs, or using MySQLdump.

1. MySQLdump

1.1 Backup

MySQLdump adopts an SQL-level backup mechanism. it imports data tables into SQL script files and is suitable for upgrading between different MySQL versions. this is also the most common MySQL backup method.

Here are some main parameters of MySQLdump:

Compatible = name it tells MySQLdump that the exported data will be compatible with the database or the old MySQL backup server. The values can be ansi, MySQL323, MySQL40, postgresql, oracle, mssql, db2, maxdb, no_key_options, no_tables_options, and no_field_options. separate them with commas. Of course, it does not guarantee full compatibility, but is as compatible as possible.

The data exported by complete-insert and-c adopts the complete INSERT method containing field names, that is, all values are written in one row. This can improve the insertion efficiency, but may be affected by the max_allowed_packet parameter, resulting in insertion failure. Therefore, you need to use this parameter with caution. at least I do not recommend this parameter.

Default-character-set = charset specifies the character set used for data export. if the data table does not use the default latin1 character set, this option must be specified during data export, otherwise, garbled characters will occur after the data is imported again.

Disable-keys tells MySQLdump to add/* at the beginning and end of the INSERT statement /*! 40000 alter table table disable keys */; and /*! 40000 alter table table enable keys */; statement, which greatly improves the speed of the insert statement because it re-creates the index after all data is inserted. This option is only applicable to MyISAM tables.

Extended-insert = true | false by default, MySQLdump enables the -- complete-insert mode. if you do not want to use it, use this option and set its value to false.

Hex-blob exports binary string fields in hexadecimal format. This option is required if binary data exists. The affected field types include BINARY, VARBINARY, and BLOB.

Lock-all-tables and-x submit a request before starting export to lock all tables in all databases to ensure data consistency. This is a global read lock and the -- single-transaction and -- lock-tables options are automatically disabled.

Lock-tables is similar to -- lock-all-tables, but instead of locking all tables in the database. This option is only applicable to MyISAM tables. for Innodb tables, you can use the -- single-transaction option.

No-create-info,-t only exports data, without adding the create table statement.

No-data,-d does not export any data, only export the database table structure.

Opt is just a quick option, it is equivalent to adding the -- add-drop-tables -- add-locking -- create-option -- disable-keys -- extended-insert -- lock-tables -- quick -- set-charset option at the same time. This option allows MySQLdump to export data quickly and export data back quickly.

This option is enabled by default, but can be disabled with -- skip-opt. Note: If the -- quick or -- opt option is not specified when running MySQLdump, the entire result set is stored in the memory. If you export a large database, problems may occur.

Quick,-q this option is useful when exporting large tables. it forces MySQLdump to directly output records from server queries rather than cache all records into memory.

Routines,-R export stored procedures and custom functions.

Single-transaction this option submits a begin SQL statement before exporting data. BEGIN does not block any applications and ensures database consistency during export. It is only applicable to transaction tables, such as InnoDB and BDB.

This option and the -- lock-tables option are mutually exclusive, because lock tables will implicitly commit any pending transactions.

To export a large table, use the -- quick option.

Triggers exports the trigger at the same time. This option is enabled by default. use -- skip-triggers to disable it.

The above content is an introduction to MySQL backup and recovery. I hope you will get some benefits.