Analyze Redshift Data in R



Create data visualizations and use high-performance statistical functions to analyze Redshift data in Microsoft R Open.

Access Redshift data with pure R script and standard SQL. You can use the CData ODBC Driver for Redshift and the RODBC package to work with remote Redshift 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 Redshift data and visualize Redshift data in R.

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 Redshift as an ODBC Data Source

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

To connect to Redshift, set the following:

  • Server: Set this to the host name or IP address of the cluster hosting the Database you want to connect to.
  • Port: Set this to the port of the cluster.
  • Database: Set this to the name of the database. Or, leave this blank to use the default database of the authenticated user.
  • User: Set this to the username you want to use to authenticate to the Server.
  • Password: Set this to the password you want to use to authenticate to the Server.

You can obtain the Server and Port values in the AWS Management Console:

  1. Open the Amazon Redshift console (http://console.aws.amazon.com/redshift).
  2. On the Clusters page, click the name of the cluster.
  3. On the Configuration tab for the cluster, copy the cluster URL from the connection strings displayed.

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 Redshift 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 Redshift Source] Driver = CData ODBC Driver for Redshift Description = My Description User = admin Password = admin Database = dev Server = examplecluster.my.us-west-2.redshift.amazonaws.com Port = 5439

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 Redshift Data as an ODBC Data Source

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

conn <- odbcConnect("CData Redshift Source")

Schema Discovery

The driver models Redshift 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 Redshift API.

orders <- sqlQuery(conn, "SELECT ShipName, ShipCity FROM Orders", believeNRows=FALSE, rows_at_time=1)

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

View(orders)

Plot Redshift Data

You can now analyze Redshift 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(orders$ShipCity, main="Redshift Orders", names.arg = orders$ShipName, horiz=TRUE)

Ready to get started?

Download a free trial of the Amazon Redshift ODBC Driver to get started:

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Learn more:

Amazon Redshift Icon Amazon Redshift ODBC Driver

The Amazon Redshift ODBC Driver is a powerful tool that allows you to connect with live Amazon Redshift data, directly from any applications that support ODBC connectivity.

Read, write, and update Amazon Redshift data through a standard ODBC Driver interface.