At the Amazon RDS FAQ there is the question "What is a database instance (DB Instance)?".

The entire answer (as of mid-June 2012) is:

You can think of a DB Instance as a database environment in the cloud with the compute and storage resources you specify. You can create and delete DB Instances, define/refine infrastructure attributes of your DB Instance(s), and control access and security via the AWS Management Console, Amazon RDS APIs, and Command Line Tools. Multiple MySQL databases or SQL Server databases (up to 30) or Oracle database schemas can be created on a given DB Instance.

The last part of that quote, "Multiple MySQL databases or SQL Server databases (up to 30) Oracle database schemas" I interpret to mean that you can have an "unlimited" number of databases on an RDS MySQL or Oracle instance but only 30 databases on an MS SQL Server instance ("unlimited" meaning not limited by the RDS infrastructure itself).

This was asked in the Stackoverflow question Does Amazon RDS support multiple databases per instance?. The answer quoted an older version of the FAQ.

What I am looking for is an Amazon document that clarifies this question, or else someone who has experience using Amazon RDS who can attest what the situation actually is.

  • I did a test and created 40 MySQL schemas in a single RDS MySQL instance, so this suggests that the RDS infrastructure does not limit the number MySQL schemas you can create.
    – user35042
    Jul 10, 2012 at 15:43

2 Answers 2


As an AWS customer using MSSQL in RDS, I can confirm the maximum amount of databases per instance (t1.micro) using SQL Express is indeed 30.

I am testing other instance sizes, and will post further if I get different results.

  • I increased my instance to a t1.small and have the same 30 database limit. Aug 13, 2012 at 18:34
  • 1
    MSSQL seem to have the limit, not MySQL
    – Chida
    Aug 13, 2012 at 19:42

RDS MySQL does not have limits for size of database or the number of databases.

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