You can't always answer your questions with a single data set. Sometimes, to answer your hardest questions, you have to integrate multiple data sets to uncover insight.
That’s why I am so excited about cross-database joins, a new feature in Tableau 10. Let me show you why this feature can be so powerful.
First, I’ll connect to a database on SQL Server to access Seattle overnight-rental data.
With this data set, I can quickly build vizzes which show all the listings in Seattle, sized and colored by nightly rates:
But what if I want to combine this with my Rental Review data set, which is in MySQL? Before Tableau 10, I could use blending, but then I wouldn’t be able to generate extracts, publish the data source, or use aggregations like MEDIAN(). With cross-database joins, I can now simply add MySQL to the data source.
Back on the data tab, click the “add” link to add other connections to this data source. You’ll notice that a number of the connection types are grayed out. That’s because they aren’t supported for cross-database joins yet. Specifically, you cannot use cross-database joins with these connection types:
I’ll click on MySQL and enter my connection information.
Once the connection is added, you’ll see it appear in the top-left part of the data tab. I’ll double-click to rename the connection:
Now I can just drag the MySQL “reviews” table into the canvas to join:
We color-code each connection so you can distinguish the tables in the join and the columns in the data grid. You can see that I have blue columns from SQL Server and orange columns from MySQL that appear side by side in the data grid! Now you can write row-level calculations using fields from both databases, or even create an extract of this multi-connection data source.
And you’re not restricted to just two connections. You can add as many of the supported connections as your analysis requires. Maybe I want to bring in the regional home-sales information as well. I’ll just drag-and-drop the text file into my data source. Note that the new data columns are colored green:
I’ll go back to the viz window and make a quick map showing zip codes colored by the average price versus average rating:
Then I’ll make another viz showing the distribution of rating reviews by zip code:
In the snapshot, I’ve highlighted Tableau’s home turf, the Fremont neighborhood, and we can see that it has a very healthy number of four-star ratings!
With Tableau 10 and cross-database joins, you can bring together all of your data, explore it in new light, and uncover new insights with just drag and drop. I’ve had a ton of fun mashing up internal data with Tableau 10. Share some of your exciting data combinations on Tableau Public!
Tableau 10 is currently in beta and is available for existing Tableau customers. Check out our beta program to learn more and sign up.
As with anything in beta, your feedback is important. So do let us know what you think.
Tableau 10 includes a brand new look and feel, and a host of new features to help you prep, analyze, and share your insights even faster. Check out our Coming Soon page for details.