Considerations for Side-by-Side Instances of SQL Server 2008 R2 and SQL Server 2008

SQL Server 2008 and SQL Server 2008 R2 share the same major version of SQL Server and therefore share some SQL Server components. When installing an instance of SQL Server 2008 R2 on the same machine as an instance of SQL Server 2008, the shared components are upgraded to the latest version, in this case SQL Server 2008 R2. 

Version Components and Numbering

The following concepts are useful in understanding the behavior of SQL Server for side-by-side instances of SQL Server, and the scenarios specific to SQL Server 2008 R2 and SQL Server 2008 side-by-side instances.

The standard product version format for SQL Server is MM.nn.bbbb.rr where each segment is defined as:

MM - Major version

nn - Minor version

bbbb - Build number

rr - Build revision number

In each major or minor release of SQL Server, there is an increment to the version number to differentiate it from earlier versions. This change to the version is used for many purposes. This includes displaying version information in the user interface, controlling how files are replaced during upgrade, applying service packs, and also as a mechanism for functional differentiation between the successive versions.

SQL Server 2008 R2 is a minor upgrade of SQL Server 2008. This means that it shares the same major version number with SQL Server 2008, and has an increment to the minor version. The product version for SQL Server 2008 R2 is 10.50.bbbb.rr. Compare this with the product version for SQL Server 2008 which is 10.0.bbbb.rr.

Components shared by all versions of SQL Server

Certain components are shared by all instances of all installed versions of SQL Server. When you install different versions of SQL Server side-by-side on the same machine, these components are automatically upgraded to the latest version. Such components are usually uninstalled automatically when the last instance of SQL Server is uninstalled.

Examples: SQL Server Browser and Microsoft SQL Server VSS Writer.

Components shared across all instances of the same major version of SQL Server

SQL Server versions that have the same major version share some components across all instances. If the shared components are selected during upgrade, the existing components are upgraded to the latest version.

Examples: Integration Services, SQL Server Management Studio, Business Intelligence Development Studio, and SQL Server Books Online.

Components shared across minor versions

SQL Server versions that have the same major.minor version shared components.

Example: Setup support files.

Components specific to an instance of SQL Server

Some SQL Server components or services are specific to an instance of SQL Server. These are also known as instance-aware. They share the same version as the instance that hosts them, and are used exclusively for that instance.

Examples: Database Engine, Analysis Services, and Reporting Services.

Components that are independent of the SQL Server versions

Certain components are installed during SQL Server setup, but are independent of the versions of SQL Server. They may be shared across major versions or by all SQL Server versions.

Examples: Microsoft Sync Framework, SQL Server Compact.

For more information about SQL Server Compact installation, see How to: Install SQL Server 2008 R2 (Setup). For more information about how to uninstall SQL Server Compact, see How to: Uninstall an Existing Instance of SQL Server (Setup).

Important The considerations that are discussed in the following sections also apply to SQL Server 2008 R2 evaluation editions. You may want to consider installing SQL Server 2008 R2 Evaluation or Developer editions on a machine that has no existing instances of SQL Server 2008.

Components shared by SQL Server 2008 R2 and SQL Server 2008

Sharing the same major version affects the installation for the shared components when SQL Server 2008 R2 and SQL Server 2008 instances exist side-by-side on the same computer. Setup runs an in-place upgrade for the selected shared components and services. The instance-aware components and the components shared by minor versions are installed side by side.

The components and services shared when you install SQL Server 2008 R2 and SQL Server 2008 side-by-side are listed below:

  • Integration Services 

  • SQL Server Browser

  • SQL Server Active Directory Helper Services

  • SQL Server Profiler

  • SQL Server Native Client

  • SQL Server Policies

  • SQL Server System CLR Types

  • SQL Server VSS Writer

  • SQLdiag Utility

  • Management Tools

    • Basic

    • Complete

  • Business Intelligence Development Studio

  • Client tools connectivity

  • Client tools SDK

  • SQL Server Books Online

  • SQL Client Connectivity SDK

Considerations for Installing/Upgrading to SQL Server 2008 R2 in a side-by-side scenario with SQL Server 2008

When you upgrade an instance of SQL Server 2008 to SQL Server 2008 R2, the shared components and services are also upgraded to SQL Server 2008 R2. During upgrade, SQL Server 2008 R2 Setup checks to see if there is an existing instance of SQL Server 2008 and issues a warning about upgrading shared components.

Nota

If you are installing a new instance of SQL Server 2008 R2, you can unselect the shared components during installation. This keeps the unselected components at the existing version of SQL Server 2008.

  • SQL Server Books Online

    If you upgrade your existing SQL Server Books Online to SQL Server 2008 R2, be aware that the content and the help topics describe SQL Server 2008 R2. For more information, see Installing SQL Server Books Online.

  • SQL Server Setup support files

    SQL Server 2008 R2 Setup includes support files for both SQL Server 2008 and SQL Server 2008 R2 because this is a shared component unique to the minor version. If the existing SQL Server 2008 Setup support files are earlier than the files included in SQL Server 2008 R2 Setup, they are updated. For more information, see Programs and Features in Control Panel for the following entries: Microsoft SQL Server 2008 Setup Support files and Microsoft SQL Server 2008 R2 Setup (English)

For more information about how to upgrade to SQL Server 2008 R2 from SQL Server 2000 and SQL Server 2005, see How to: Upgrade to SQL Server 2008 R2 (Setup).

Review the considerations for updating side-by-side instances of SQL Server 2008 R2 and SQL Server 2008 before you install SQL Server 2008 R2 side by side with SQL Server 2008 instances on the same machine.

Considerations for Installing/Upgrading to SQL Server 2008 R2 in a side-by-side scenario with SQL Server 2005

The following are the Integration Services installation and upgrade scenarios when SQL Server 2005 Integration Services (SSIS) is installed on the machine.

  • If you specify the upgrade scenario, SQL Server 2005 Integration Services (SSIS) is upgraded to SQL Server 2008 R2 Integration Services.

  • If you specify the installation scenario, SQL Server 2008 R2 Integration Services is installed side-by-side with SQL Server 2005 Integration Services (SSIS).

The following are the Integration Services installation and upgrade scenarios when SQL Server 2005 Integration Services (SSIS)and SQL Server 2008 Integration Services (SSIS) are installed on the machine.

  • If you specify the upgrade scenario, both SQL Server 2005 Integration Services (SSIS)and SQL Server 2008 Integration Services (SSIS) are upgraded to SQL Server 2008 R2 Integration Services, even if you intended to upgrade only SQL Server 2008 Integration Services (SSIS).

  • If you specify the installation scenario, SQL Server 2008 Integration Services (SSIS) is upgraded to SQL Server 2008 R2 Integration Services. SQL Server 2005 Integration Services (SSIS) remains installed on the machine, side-by-side with SQL Server 2008 R2 Integration Services.

    Subsequent upgrades from SQL Server 2008 R2 Integration Services to other versions, does not result in upgrading SQL Server 2005 Integration Services (SSIS) to other versions.

Considerations for Uninstalling SQL Server 2008 R2 on a machine with an existing instance of SQL Server 2008

  • Shared components and tools

    Shared components and tools are not uninstalled automatically when you uninstall a SQL Server 2008 R2 instance. Setup does not block the uninstallation of shared components, but gives you a warning if it detects an existing SQL Server 2008 instance on the machine. Be aware that uninstalling the shared components renders any remaining SQL Server 2008 instance unusable.

  • Setup support files

    SQL Server 2008 R2 Setup installs support files for both SQL Server 2008 Setup and SQL Server 2008 R2 Setup. Uninstalling the Setup support files corrupts the side-by-side installation with SQL Server 2008. You can reinstall SQL Server 2008 Setup support files from the SqlSupport.msi installer package in the SQL Server 2008 R2 installation media.

  • SQL Server Browser

    In SQL Server 2008 and SQL Server 2008 R2, the SQL Server Browser is a separate installation, performed automatically with the installation of the Database Engine or Analysis Services. The SQL Server Browser uninstalls automatically when the last instance of SQL Server 2008 or SQL Server 2008 R2 is uninstalled. For more information about uninstalling when you have an existing SQL Server 2005 instance, see How to: Uninstall an Existing Instance of SQL Server (Setup).

  • SQL Server Database Engine

    If you uninstall the SQL Server 2008 R2 Database Engine, be aware that the replication client components are not uninstalled automatically.

For more information about how to uninstall SQL Server 2008 R2, see How to: Uninstall an Existing Instance of SQL Server (Setup).

Considerations for Updating Side by Side Instances of SQL Server 2008 and SQL Server 2008 R2.

  • If you have a SQL Server 2008 R2 instance installed side by side with a SQL Server 2008 instance, you need to download and install the updates specific to each version.

  • When you install a SQL Server 2008 R2 instance side by side with a SQL Server 2008 instance, the shared components are upgraded to SQL Server 2008 R2. If you later decide to uninstall the SQL Server 2008 R2 instance, you still need to download and install SQL Server 2008 R2 updates to the shared components.

  • SQL Server 2008 R2 Setup includes the installation of the SQL Server 2008 setup support files even if there is no existing SQL Server 2008 instance on the same machine. It is therefore a good practice to download SQL Server 2008 updates to keep the SQL Server 2008 setup support files up to date.

Change History

Updated content

Added information about the Integration Services installation and upgrade scenarios when SQL Server 2005 Integration Services (SSIS) is installed on the machine, and when SQL Server 2005 Integration Services (SSIS) and SQL Server 2008 Integration Services (SSIS) are installed on the machine.