Database Backup (DBS) allows you to back up your databases in a continuous and cost-effective manner. DBS supports two backup methods: logical backup and physical backup. This topic describes how to select a backup method.

Differences between backup methods

Item Logical backup Physical backup
Backup object Database objects such as tables, indexes, and stored procedures. Database files on operating systems.
Full backup DBS splits the data of all tables in a database and executes SQL statements on the database to read the data in multiple threads in parallel. A DBS backup gateway is installed on the server of a database for database backups.
Incremental backup DBS backs up incremental data in real time based on the logs stored in the memory of a database. This prevents the sudden I/O performance drop that may occur when a large amount of data is backed up at a time. The speed at which database logs are read varies with the rate at which they are generated.
Features
  • Finer-grained backup can be performed on databases and tables.
  • Databases are not locked during data backup. This minimizes the impact of data backup on database performance.
  • A database instance can be backed up only as a whole.
  • Data is read from the disks of a database, which affects the I/O performance of the database.
  • In most cases, the speeds of physical backup and restoration are faster than the speeds of logical backup and restoration.
    Note You can create DBS sandbox instances to use your backup data with ease. For more information, see Overview.
Recommended database size < 1 TB. ≥ 1 TB.
Supported databases
  • Databases created in Alibaba Cloud support only the logical backup method.
  • For information about the backup method supported by each type of database, see Database engines and features.
Whether it is necessary to Add a backup gateway No Yes