Data backup compression technology in MySQL

In the MySQL database, backup is a very important link. Data backup can be used to restore data, protect data security, and quickly restore data to its previous state when a database fails to avoid data loss. In the process of backing up data, in order to save storage space and transmission time, we need to use data backup compression technology.

The data backup compression technology in MySQL can be mainly divided into two categories: physical backup and logical backup. Physical backup refers to copying the contents of the database file system to a backup file, usually using the "cp" command or the "tar" command and other conventional backup methods of Linux systems. The advantage of this backup method is that the backup speed is faster, data restoration is easier, and the backup data is more reliable. However, the disadvantages are also obvious. Backup files are often larger, occupying storage space, and it takes longer to transfer backup data. To solve this problem, we need to use data compression technology.

Logical backup refers to exporting the data in the database to a backup file in the form of SQL language, which can be achieved through the "mysqldump" command. The advantage of logical backup is that the backup file is smaller and the time to transfer the backup data is shorter. However, because the SQL statements need to be executed one by one when restoring data, the restoration process is relatively slow. For databases with large amounts of data, the restoration process of logical backups may take hours or even days.

In order to find a balance between physical backup and logical backup, we need to use backup compression technology. Backup compression technology can reduce the size of backup files to a very small part of their original size. In the MySQL database, there are two commonly used backup compression technologies:

1. gzip compression

gzip is a commonly used compression tool under Linux systems. In the MySQL database Using gzip can reduce the size of the backup file to about half of its original size. Compression using the gzip command is very simple. You only need to execute the following command after the backup is completed:

gzip backup.sql

The above command will compress the "backup.sql" file in the current directory into "backup.sql.gz" Compressed file. If you need to decompress the backup file, just execute the following command:

gzip -d backup.sql.gz

2. tar compression

tar is a commonly used backup tool that can also be used in MySQL databases Perform backup compression. Unlike gzip, tar can package multiple files or folders together into a compressed file. There are several steps to use tar for backup and compression:

(1) Pack the files or folders that need to be backed up:

tar -zcvf backup.tar.gz /path/to/backup/file/

The above command will change "/path/to/backup/file /" directory into a compressed file of "backup.tar.gz".

(2) Decompress the backup file:

tar -zxvf backup.tar.gz

The above command will decompress the "backup.tar.gz" compressed file in the current directory.

Backup compression technology is a very important technology, especially in MySQL database, which needs to be used to save storage space and transmission time. The two backup compression technologies introduced above, namely gzip compression and tar compression, are commonly used backup compression solutions in MySQL databases.

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