This topic describes the limits of ApsaraDB RDS for SQL Server. Before you use ApsaraDB RDS for SQL Server, we recommend that you familiarize yourself with these limits to ensure the stability and security of your database system.

Item RDS Cluster Edition RDS High-availability Edition RDS Basic Edition

SQL Server 2019 EE

SQL Server 2017 EE

SQL Server 2019 SE

SQL Server 2017 SE

SQL Server 2016 SE and SQL Server 2016 EE

SQL Server 2012 SE and SQL Server 2012 EE

SQL Server 2008 R2

SQL Server 2012 Web and SQL Server 2016 Web

SQL Server 2012 SE and SQL Server 2016 SE

SQL Server 2012 EE Basic

SQL Server 2016 EE

Maximum number of databases (For more information, see the "Maximum number of databases" section of this topic.) 300 300 50 400
Maximum number of database accounts Unlimited Unlimited 500 Unlimited
Creation of accounts, logon connections, and databases Supported Supported Supported Supported
Database-level DDL triggers Supported Supported Not supported Supported
Database permission authorization Supported Supported Not supported Supported
Permissions to terminate threads Supported Supported Supported Supported
Linked server Supported (Linked servers are not supported for the shared instance family.) Supported (Linked servers are not supported for the shared instance family.) Not supported Not supported
Distributed transactions Supported Supported Not supported Not supported
SQL Server Profiler Supported Supported Supported Supported
Tuning Advisor Supported Supported Not supported Supported
Change data capture (CDC) Supported Not supported Not supported Not supported
Change tracking Supported Supported Not supported Supported
Logon by using Windows domain accounts Supported (Logon by using Windows domain accounts is not supported for the shared instance family.) Supported (Logon by using Windows domain accounts is not supported for the shared instance family.) Not supported Not supported
Email Not supported Not supported
SQL Server Integration Services (SSIS)
SQL Server Analysis Services (SSAS)
SQL Server Reporting Services (SSRS)
R Services
Common Language Runtime (CLR)
Asynchronous communication
Replication
Policy management

Maximum number of databases

An ApsaraDB RDS instance that runs SQL Server 2008 R2 supports up to 50 databases. If your RDS instance runs other SQL Server versions, the maximum number of databases varies based on the RDS edition. You can use the following formulas to calculate the maximum number of databases:
  • RDS Cluster Edition and RDS High-availability Edition

    You must extract the square root of the number of cores, round the square root down to the integer, and then multiply the integer by 50. Assume that the obtained value is X. In this example, the maximum number of databases equals the smaller value between X and 300. For example, if your RDS instance runs SQL Server 2016 SE on RDS High-availability Edition that provides 4 cores and 8 GB of memory, the RDS instance supports a maximum of 100 databases.

  • RDS Basic Edition

    You must extract the square root of the number of cores, round the square root down to the integer, and then multiply the integer by 100. Assume that the obtained value is Y. In this example, the maximum number of databases equals the smaller value between Y and 400. For example, if your RDS instance runs SQL Server 2019 SE on RDS Basic Edition that provides 4 cores and 8 GB of memory, the RDS instance supports a maximum of 200 databases.

Note min in the preceding formulas indicates that the smaller value between two values is used. For example, the value of min{100,300} is 100.