Can SQL 2012 and 2014 Coexist?
As a database professional, I’ve often encountered the question of whether SQL Server 2012 and SQL Server 2014 can coexist on the same server. It’s a valid concern, especially when you have multiple applications running on different versions of SQL Server.
The short answer is yes, SQL Server 2012 and SQL Server 2014 can coexist on the same server. However, there are a few considerations and steps to follow to ensure a smooth coexistence between these two versions.
Compatibility Mode
When installing SQL Server 2014 alongside SQL Server 2012, you need to pay close attention to compatibility mode. Compatibility mode ensures that the databases created in SQL Server 2012 can be accessed and used by SQL Server 2014.
To set the compatibility mode, you can use the following T-SQL command:
ALTER DATABASE [YourDatabaseName] SET COMPATIBILITY_LEVEL = 110;
This command sets the compatibility level to 110, which corresponds to SQL Server 2012. By doing this, you ensure that your existing databases are compatible with SQL Server 2012 and SQL Server 2014.
Instance Configuration
Another crucial aspect to consider is the instance configuration. When installing SQL Server 2014, make sure to select a unique instance name. This allows you to have both SQL Server 2012 and SQL Server 2014 running on the same server without conflicts.
During the installation process, you will be prompted to specify the instance name. Choose a meaningful and distinct name to avoid confusion. For example, you can name your SQL Server 2014 instance “SQL2014” while keeping the default instance name for SQL Server 2012.
Port Configuration
Port configuration is another critical factor when running multiple instances of SQL Server on the same server. Each instance needs to use a unique port number to avoid conflicts.
During the SQL Server 2014 installation process, you will have the option to specify a port number for the instance. Make sure to choose a different port number than the one used by SQL Server 2012.
Connectivity and Security
When working with multiple SQL Server instances, it’s essential to ensure seamless connectivity and security. You need to configure the necessary protocols and firewall settings to allow connections to both SQL Server 2012 and SQL Server 2014.
Additionally, you must grant appropriate permissions and security settings for each instance to maintain data integrity and protect against unauthorized access.
Conclusion
In conclusion, SQL Server 2012 and SQL Server 2014 can indeed coexist on the same server. By carefully considering compatibility mode, instance configuration, port configuration, and ensuring connectivity/security, you can have a stable and efficient environment running both versions simultaneously.
As a database professional, I’ve successfully implemented this coexistence in several projects, allowing companies to migrate gradually from SQL Server 2012 to SQL Server 2014 without disrupting their existing applications.