Single Data Source > Joining > Blending
One of the beauties of Tableau is the ease with which you can connect to many different data sources in various ways. As mentioned earlier in this book, there are 50 connectors defined in Tableau 10 for interfacing with a variety of data sources. Furthermore, this flexibility extends beyond simply connecting to single tables or files. Previous versions of Tableau accommodated joining within data sources and data blending of disparate data sources. Tableau 10 can even accommodate cross-joining data sources.
Although Tableau makes it easy to connect to various data sources, it should be stressed that Tableau is not an Extract, Transform, and Load (ETL) tool. If complex joins and complex data blending are required to generate useful results, it may be advisable to perform ETL work outside of Tableau. Such ETL work will ideally lead to better data modeling and thus easier authoring and quicker performance in Tableau.
