How Many Databases Can Run on an RDS DB Instance?

The maximum number of databases that can run on an RDS DB instance depends on the DB engine settings.

If there are enough CPU, memory, and storage resources, there are no limitations to the number of databases running on a DB instance. However, the number of tables in the databases affects the backup speed. If the number of tables exceeds 500,000, the backup will fail.

• MySQL allows you to create numerous databases and tables. For details, see the official MySQL documentation.
• PostgreSQL allows you to create numerous databases and database accounts.
• Microsoft SQL Server allows you to create a maximum of 100 databases and numerous database accounts.