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.
| Feature | 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 Maximum number of databases.) | 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 (Logon by using Windows domain accounts is not supported for the shared instance family.) | Not supported | Not supported |
| Distributed transaction | Supported | Supported | Not supported | Not supported |
| SQL Profiler | Supported | Supported | Supported | Supported |
| Tuning Advisor | Supported | Supported | Not supported | Supported |
| Change data capture (CDC) | Supported | Supported Note This feature is not supported for SQL Server 2012 SE. | 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 |
| 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
- 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 and use the instance type 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 and use the instance type that provides 4 cores and 8 GB of memory, the RDS instance supports a maximum of 200 databases.