Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Upgrading an Amazon RDS Custom for SQL Server DB instance

You can upgrade an Amazon RDS Custom for SQL Server DB instance by modifying it to use a new DB engine version. For general information about upgrading DB instances, see Upgrading a DB instance engine version.

Overview of upgrades in RDS Custom for SQL Server

Amazon RDS Custom for SQL Server supports major and minor version upgrades. Minor version upgrades can include security patches, bug fixes, and engine improvements. Microsoft releases these updates as cumulative updates (CUs). Major version upgrades introduce new features and engine changes between versions, like upgrading from SQL Server 2019 to 2022. You can apply both upgrades immediately or during scheduled maintenance windows. To prevent potential backward compatibility issues, we recommend testing your applications in a non-production environment before upgrading.

RDS Custom for SQL Server allows you to upgrade an RDS Provided Engine Version (RPEV) or a Custom Engine Version (CEV).

If you upgrade an RDS Custom for SQL Server DB instance in a Multi-AZ deployment, RDS Custom for SQL Server performs rolling upgrades for your instance. This approach minimizes downtime by upgrading one instance at a time. RDS performs the following actions to perform rolling upgrades:

The DB instance downtime for Multi-AZ deployments is the time it takes for the failover.

The following limitations apply when upgrading an RDS Custom for SQL Server DB instance:

Upgrading major and minor engine version

Both major and minor engine version upgrades are irreversible and must always be done to a newer version. To identify available target versions, use the Amazon Web Services Management Console and choose from the available versions when modifying your DB instance. Alternatively, use the describe-db-engine-versions CLI command or DescribeDBEngineVersions RDS API command.

For Linux, macOS, or Unix:

aws rds describe-db-engine-versions \
    --engine custom-sqlserver-se \
    --engine-version 15.00.4322.2.v1 \
    --query "DBEngineVersions[*].ValidUpgradeTarget[*].{EngineVersion:EngineVersion}" \
    --output table

For Windows:

aws rds describe-db-engine-versions ^
    --engine custom-sqlserver-se ^
    --engine-version 15.00.4322.2.v1 ^
    --query "DBEngineVersions[*].ValidUpgradeTarget[*].{EngineVersion:EngineVersion}" ^
    --output table

The output shows the available target engine versions:

--------------------------
|DescribeDBEngineVersions|
+------------------------+
|      EngineVersion     |
+------------------------+
|  15.00.4410.1.v1       |
|  15.00.4415.2.v1       |
|  15.00.4430.1.v1       |
|  16.00.4165.4.v1       |
|  16.00.4175.1.v1       |
|  16.00.4185.3.v1       |
+------------------------+

After identifying your target version, use the Amazon Web Services Management Console and follow the instructions in Modifying an RDS Custom for SQL Server DB instance. Alternatively, use modify-db-instance CLI command or ModifyDBInstance RDS API command.

For Linux, macOS, or Unix:

aws rds modify-db-instance \
    --db-instance-identifier DB_INSTANCE_IDENTIFIER \
    --engine-version ENGINE_VERSION \
    --allow-major-version-upgrade \
    --region Region \
    --no-apply-immediately 

For Windows:

aws rds modify-db-instance ^
    --db-instance-identifier DB_INSTANCE_IDENTIFIER ^
    --engine-version ENGINE_VERSION ^
    --allow-major-version-upgrade ^
    --region Region ^
    --no-apply-immediately    

Database compatibility level

You can use Microsoft SQL Server database compatibility levels to adjust some database behaviors to mimic previous versions of SQL Server. For more information, see Compatibility level in the Microsoft documentation.

When you upgrade your DB instance, all existing databases remain at their original compatibility level. For example, if you upgrade from SQL Server 2019 to SQL Server 2022, all existing databases have a compatibility level of 150. Any new database created after the upgrade have compatibility level 160.

You can change the compatibility level of a database by using the ALTER DATABASE command. For example, to change a database named customeracct to be compatible with SQL Server 2022, issue the following command:

ALTER DATABASE customeracct SET COMPATIBILITY_LEVEL = 160