MySQL Backup and Restore: Logical Backups

What Are Logical Backups?

Logical backups capture the database's structure and contents as SQL commands, such as CREATE TABLE and INSERT statements.

Unlike physical backups, which copy raw data files, logical backups are human-readable and can be edited or reviewed before restoration.

• Export schema and data as SQL statements.
• Portable across different MySQL versions and platforms.
• Useful for migrations, upgrades, and partial restores.

Using mysqldump for Logical Backups

The mysqldump utility is the standard tool for creating logical backups in MySQL.

It connects to the MySQL server, extracts database objects and data, and writes them to a text file.

• Basic syntax: mysqldump -u [user] -p [database_name] > backup.sql
• Use --all-databases to back up all databases.
• Add --routines and --triggers to include stored procedures and triggers.

Restoring from Logical Backups

Restoring a logical backup involves executing the SQL statements contained in the dump file.

You can use the mysql command-line client to import the backup.

• Basic restore syntax: mysql -u [user] -p [database_name] < backup.sql
• Ensure the target database exists or create it before restoring.
• Restoring all databases requires appropriate privileges.

Best Practices for Logical Backups

Following best practices ensures your backups are reliable and restorations are smooth.

• Regularly schedule backups to minimize data loss.
• Test restores periodically to verify backup integrity.
• Include routines and triggers in backups if used.
• Compress backup files to save storage space.
• Secure backup files to prevent unauthorized access.

Common Mistakes to Avoid

Avoiding common pitfalls will save time and prevent data loss.

• Not including all necessary database objects (e.g., triggers, stored procedures).
• Failing to verify backups by testing restores.
• Overwriting backups without keeping historical copies.
• Backing up live databases without locking tables or using consistent snapshots.
• Ignoring error messages during backup or restore operations.