Before your applications can connect to an ApsaraDB RDS for SQL Server instance, you must create a database on the instance. This topic describes how to create a database through the console and explains the maximum number of databases your instance supports.
Prerequisites
Before you begin, ensure that you have:
An ApsaraDB RDS for SQL Server instance. For instructions, see Create an ApsaraDB RDS for SQL Server instance.
Database limits
The maximum number of databases per instance depends on the instance edition and CPU cores.
SQL Server 2008 R2: 50 databases (fixed limit).
Other SQL Server versions: The limit varies by edition.
RDS Cluster Edition / RDS High-availability Edition:
max = min(floor(√CPU_cores) × 50, 300)
RDS Basic Edition:
max = min(floor(√CPU_cores) × 100, 400)
The following table shows the limits for common CPU configurations:
| CPU cores | Cluster Edition / High-availability Edition | Basic Edition |
|---|---|---|
| 1 | 50 | 100 |
| 2 | 50 | 100 |
| 4 | 100 | 200 |
| 8 | 100 | 200 |
| 16 | 200 | 400 |
| 32 | 250 | 400 |
| 64 | 300 | 400 |
For a 4-core instance running SQL Server 2016 SE on RDS High-availability Edition, the limit ismin(floor(√4) × 50, 300)=min(100, 300)= 100 databases.
Create a database
Go to the Instances page. In the top navigation bar, select the region where the instance resides. Find the instance and click its ID.
In the left-side navigation pane, click Databases.
Click Create Database, configure the parameters, and then click Create.
Parameter Description Database Name The database name. 2–64 characters. Allowed characters: letters, digits, underscores ( _), and hyphens (-). Must start with a letter and end with a letter or digit. Chinese characters are not allowed.Supported Character Set The character set of the database. Description Optional description of the database. Up to 256 characters.
What to do next
After creating the database, authorize an account to access it so your applications can connect. For instructions, see the account management documentation for ApsaraDB RDS for SQL Server.
To create databases programmatically, use the CreateDatabase API operation.
To connect to the instance, use Data Management (DMS) or SQL Server Management Studio (SSMS).
FAQ
Why do I get the error "The current database name is incorrect. Please reset the database name."?
This error (code: InvalidDBName.Duplicate) means a database with the same name already exists on the instance. The console only shows databases in ONLINE status, so the conflicting database may not be visible if it is in RESTORING, RECOVERING, or OFFLINE state.
To confirm, connect to the instance using SQL Server Management Studio (SSMS) and run:
SELECT
[name] AS DatabaseName,
state_desc AS StateDescription,
recovery_model_desc AS RecoveryModel
FROM
sys.databases
WHERE
database_id > 4; -- Exclude system databases
Once you identify the conflicting database, resolve it based on its status:
The database is in a non-ONLINE state (OSS backup recovery with incremental option)
When recovering from an OSS backup with the Access Pending (Incremental Backup) option selected, the database stays in a non-ONLINE state until you explicitly open it.
To continue uploading incremental backup files: open the database from the Cloud Migration Records of Backup Data tab after recovery is complete.
To stop incremental recovery: open the database directly.
To recreate the database: open it first, then delete it, and create a new one.
The database is in `RECOVERING` state (transaction log space full)
When transaction log space is full, the database enters the RECOVERING state. Check the instance error logs to confirm.
If the instance storage is full: expand the instance storage space, then restart the instance. The database returns to
ONLINEstatus after recovery completes.If only the log file growth limit is reached (instance storage not full): adjust the log file size limit without restarting.
To recreate the database: wait for the status to return to
ONLINE, then delete it and create a new one.
The database is in `OFFLINE` state (manually set)
Use the sp_rds_set_db_online stored procedure to bring it back online:
USE master;
GO
EXEC sp_rds_set_db_online 'database_name';
GOTo recreate the database: wait for ONLINE status, then delete it and create a new one.