Change the default R or Python language runtime version
Applies to: 
SQL Server 2016 (13.x)
SQL Server 2017 (14.x)
This article describes how to change the default version of R or Python used in SQL Server 2016 R Services or SQL Server 2017 Machine Learning Services.
The following lists the versions of the R and Python runtime that are included in the different SQL Server versions.
| SQL Server version | Service | Cumulative Update | R runtime versions | Python runtime version |
|---|---|---|---|---|
| SQL Server 2016 | R Services | RTM - SP2 CU13 | 3.2.2 | Not available |
| SQL Server 2016 | R Services | SP2 CU14 and later | 3.2.2 and 3.5.2 | Not available |
| SQL Server 2017 | Machine Learning Services | RTM - CU21 | 3.3.3 | 3.5.2 |
| SQL Server 2017 | Machine Learning Services | CU22 and later | 3.3.3 and 3.5.2 | 3.5.2 and 3.7.2 |
Prerequisites
You need to install a Cumulative Update (CU) to change the default R or Python language runtime version:
- SQL Server 2016: Services Pack (SP) 2 Cumulative Update (CU) 14 or later
- SQL Server 2017: Cumulative Update (CU) 22 or later
To download the latest Cumulative Update, see the Latest updates for Microsoft SQL Server.
Note
If you slipstream the Cumulative Update with a new installation of SQL Server, only the newest versions of the R and Python runtime will be installed.
Change R runtime version
If you have installed one of the above Cumulative Updates for SQL Server 2016 or 2017, you may have multiple versions of R in a SQL instance. Each version is contained in a subfolder of the instance folder with the name R_SERVICES.<major>.<minor> (the folder from the original installation may not have a version number appended to the folder name).
If you install a CU containing R 3.5, the new R_SERVICES folder is:
- SQL Server 2016:
C:\Program Files\Microsoft SQL Server\MSSQL13.<INSTANCE_NAME>\R_SERVICES.3.5 - SQL Server 2017:
C:\Program Files\Microsoft SQL Server\MSSQL14.<INSTANCE_NAME>\R_SERVICES.3.5
Each SQL instance uses one of these versions as the default version of R. You can change the default version by using the RegisterRext.exe command-line utility. The utility is located under the R folder in each SQL instance:
<SQL instance path>\R_SERVICES.n.n\library\RevoScaleR\rxLibs\x64\RegisterRext.exe
Note
The functionality described in this article is available only with the copy of RegisterRext.exe included in SQL CUs. Don't use the copy that came with the original SQL installation.
To change the R runtime version, pass the following command line arguments to RegisterRext.exe:
/configure- Required, specifies that you're configuring the default R version./instance:<instance name> - Optional, the instance you want to configure. If not specified, the default instance is configured./rhome:<path to the R_SERVICES[n.n] folder> - Optional, path to the runtime version folder you want to set as the default R version.If you don't specify /rhome, the path configured is the path under which RegisterRext.exe is located.
Examples
Below are examples on how to change the R runtime version in SQL Server 2016 and 2017.
Change R runtime version in SQL Server 2016
For example, to configure R 3.5 as the default version of R for the instance MSSQLSERVER01 on SQL Server 2016:
cd "C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER01\R_SERVICES.3.5\library\RevoScaleR\rxLibs\x64"
.\RegisterRext.exe /configure /rhome:"C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER01\R_SERVICES.3.5" /instance:MSSQLSERVER01
Change R runtime version in SQL Server 2017
For example, to configure R 3.5 as the default version of R for the instance MSSQLSERVER01 on SQL Server 2017:
cd "C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER01\R_SERVICES.3.5\library\RevoScaleR\rxLibs\x64"
.\RegisterRext.exe /configure /rhome:"C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER01\R_SERVICES.3.5" /instance:MSSQLSERVER01
In these examples, you don't need to include the /rhome argument since you're specifying the same folder where RegisterRext.exe is located.
Change Python runtime version
If you have installed CU22 or later for SQL Server 2017, you may have multiple versions of Python in a SQL instance. Each version is contained in a subfolder of the instance folder with the name PYTHON_SERVICES.<major>.<minor> (the folder from the original installation may not have a version number appended to the folder name).
For example, if you install a CU containing Python 3.7, a new PYTHON_SERVICES folder is created:
C:\Program Files\Microsoft SQL Server\MSSQL14.<INSTANCE_NAME>\PYTHON_SERVICES.3.7
Each SQL instance uses one of these versions as the default version of Python. You can change the default version by using the RegisterRExt.exe command-line utility. The utility is located under the Python folders in each SQL instance:
<SQL instance path>\PYTHON_SERVICES.n.n\Lib\site-packages\revoscalepy\rxLibs\RegisterRExt.exe
Note
The functionality described in this article is available only with the copy of RegisterRExt.exe included in SQL CUs. Don't use the copy that came with the original SQL installation.
To change the Python runtime version, pass the following command line arguments to RegisterRext.exe:
/configure- Required, specifies that you're configuring the default Python version./python- Specifies that you're configuring the default Python version. Optional if you specify/pythonhome./instance:<instance name> - Optional, the instance you want to configure. If not specified, the default instance is configured./pythonhome:<path to the PYTHON_SERVICES[n.n] folder> - Optional, path to the runtime version folder you want to set as the default Python version.If you don't specify /pythonhome, the path configured is the path under which RegisterRExt.exe is located.
Example
For example, to configure Python 3.7 as the default version of Python for the instance MSSQLSERVER01 on SQL Server 2017:
cd "C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER01\PYTHON_SERVICES.3.7\Lib\site-packages\revoscalepy\rxLibs"
.\RegisterRext.exe /configure /pythonhome:"C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\PYTHON_SERVICES.3.7" /instance:MSSQLSERVER01
In this example, you don't need to include the /pythonhome argument since you're specifying the same folder where RegisterRext.exe is located.
Remove a runtime version
To remove a version of R or Python, use RegisterRExt.exe with the /cleanup command-line argument, using the same /rhome, /pythonhome, and /instance arguments described previously.
For example, to remove the R 3.2 folder from the instance MSSQLSERVER01:
.\RegisterRext.exe /cleanup /rhome:"C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER01\R_SERVICES" /instance:MSSQLSERVER01
For example, to remove the Python 3.7 folder from the instance MSSQLSERVER01:
.\RegisterRExt.exe /cleanup /python /pythonhome:"C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER01\PYTHON_SERVICES.3.7" /instance:MSSQLSERVER01
RegisterRext.exe will ask you to confirm the clean up of the specified R runtime:
Are you sure you want to permanently delete the given runtime along with all the packages installed on it? [Yes(Y)/No(N)/Default(Yes)]:
To confirm, answer Y or press enter. Alternatively, you can skip this prompt by passing in /y or /Yes along the /cleanup option.
Note
You can remove a version only if it's not configured as the default and it's not currently being used to run RegisterRext.exe.