Editing and Working with Tableau Data Sources (Adding data)

This article describes the expected behavior when you change or modify the data connection for each type of Tableau data source. Consider the following when changing or modifying the data connection:

• Tableau always loads the data source matching field names and types as best as possible to preserve the views.
• Tableau will automatically add or remove the fields as the data changes. Occasionally, removed fields will display a red exclamation mark. This fields may be removed after you replace references. See the Online Help for directions on how to do this.

Note: You cannot switch data source types. For example, Tableau will not change from Oracle to PostgresSQL, or from SQL Server to Microsoft Access.

Data source	Expected behavior in ideal conditions
Microsoft Excel	You are connected to two Excel worksheets in one Excel workbook file via a join, and you want to change the connection to a different Excel worksheet in a different Excel workbook. Step 1 For 7.0 and later, select the data source on the Data menu, and then select  Edit Connection. For 6.1 and earlier, select Data > Data Connection > Edit. Step 2 In the Excel Workbook Connection dialog box, click Browse, and then browse to the location of the Excel workbook that contains the worksheet you want to use. If the fields in this new Excel workbook match the fields in the old file, the Tableau information is preserved. Step 3 Select the new data source, and click Open. Step 4 Click OK.
Microsoft Access	Same answer as for Excel.
PostgreSQL, Firebird, IBM DB2, MySQL, Microsoft SQL Server, Netezza, Teradata, and Vertica	You can change the server, port, database, user, and password. If the details of your table connections and table joins are the same in the old and new data sources, the Tableau information is preserved.
Oracle	Similar to above, and you can also switch between Oracle schema owners.
MS Analysis Services and Oracle Essbase	You can swap cube sources, but note that the entire definition is replaced. You receive a warning that the worksheet contains errors and that invalid fields will be removed. Making this change is not recommended.
Tableau Data Extract	Similar to Excel
Text files	Similar to Excel. However, the table names are the file names. The simplest way to achieve a smooth transition is to create a copy of the entire directory containing these files.