Analyze Snowflake Data in R via ODBC

Access Snowflake data with pure R script and standard SQL. You can use the CData ODBC Driver for Snowflake and the RODBC package to work with remote Snowflake data in R. By using the CData Driver, you are leveraging a driver written for industry-proven standards to access your data in the popular, open-source R language. This article shows how to use the driver to execute SQL queries to Snowflake data and visualize Snowflake data in R.

Getting Started

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Install R

You can complement the driver's performance gains from multi-threading and managed code by running the multithreaded Microsoft R Open or by running R linked with the BLAS/LAPACK libraries. This article uses Microsoft R Open (MRO).

Connect to Snowflake as an ODBC Data Source

Information for connecting to Snowflake follows, along with different instructions for configuring a DSN in Windows and Linux environments.

To connect to Snowflake:

1. Set User and Password to your Snowflake credentials and set the AuthScheme property to PASSWORD or OKTA.
2. Set URL to the URL of the Snowflake instance (i.e.: https://myaccount.snowflakecomputing.com).
3. Set Warehouse to the Snowflake warehouse.
4. (Optional) Set Account to your Snowflake account if your URL does not conform to the format above.
5. (Optional) Set Database and Schema to restrict the tables and views exposed.
6. (Optional) If MFA is enabled on your Snowflake account (via Duo Security), set MFACode to the passcode generated by your Duo authenticator app.

See the Getting Started guide in the CData driver documentation for more information.

When you configure the DSN, you may also want to set the Max Rows connection property. This will limit the number of rows returned, which is especially helpful for improving performance when designing reports and visualizations.

Windows

If you have not already, first specify connection properties in an ODBC DSN (data source name). This is the last step of the driver installation. You can use the Microsoft ODBC Data Source Administrator to create and configure ODBC DSNs.

Linux

If you are installing the CData ODBC Driver for Snowflake in a Linux environment, the driver installation predefines a system DSN. You can modify the DSN by editing the system data sources file (/etc/odbc.ini) and defining the required connection properties.

/etc/odbc.ini

[CData Snowflake Source]
Driver = CData ODBC Driver for Snowflake
Description = My Description
Authscheme = Password
URL = https://myaccount.snowflakecomputing.com
User = Admin
Password = test123
Server = localhost
Database = Northwind
Warehouse = TestWarehouse
Account = Tester1
MFACode = YourMFACode

For specific information on using these configuration files, please refer to the help documentation (installed and found online).

Load the RODBC Package

To use the driver, download the RODBC package. In RStudio, click Tools -> Install Packages and enter RODBC in the Packages box.

After installing the RODBC package, the following line loads the package:

library(RODBC)

Note: This article uses RODBC version 1.3-12. Using Microsoft R Open, you can test with the same version, using the checkpoint capabilities of Microsoft's MRAN repository. The checkpoint command enables you to install packages from a snapshot of the CRAN repository, hosted on the MRAN repository. The snapshot taken Jan. 1, 2016 contains version 1.3-12.

library(checkpoint)
checkpoint("2016-01-01")

Connect to Snowflake Data as an ODBC Data Source

You can connect to a DSN in R with the following line:

conn <- odbcConnect("CData Snowflake Source")

Schema Discovery

The driver models Snowflake APIs as relational tables, views, and stored procedures. Use the following line to retrieve the list of tables:

sqlTables(conn)

Execute SQL Queries

Use the sqlQuery function to execute any SQL query supported by the Snowflake API.

products <- sqlQuery(conn, "SELECT Id, ProductName FROM Products", believeNRows=FALSE, rows_at_time=1)

You can view the results in a data viewer window with the following command:

View(products)

Plot Snowflake Data

You can now analyze Snowflake data with any of the data visualization packages available in the CRAN repository. You can create simple bar plots with the built-in bar plot function:

par(las=2,ps=10,mar=c(5,15,4,2))
barplot(products$ProductName, main="Snowflake Products", names.arg = products$Id, horiz=TRUE)

👁 A basic bar plot. (Salesforce is shown.)