Using a .tdc File with Tableau Server

Published: 24 Jul 2014
Last Modified Date: 08 Nov 2023


How to use a .tdc file with Tableau Server for data connection customizations.

A TDC file is used to create customizations for specific data sources for users on Tableau Server.  For more information on TDC files, please review this Tableau Online Help.


  • Tableau Server


Important: Tableau does not test or support .tdc files. These files should be used as a tool to explore or occasionally address issues with your data connection. Creating and maintaining .tdc files requires careful manual editing, and there is no support for sharing these files.  Work with your Database Administrator and Tableau Administrator to complete the following tasks.
1. Using a text editor, such as Notepad, Notepad++, or Sublime, copy and paste the entire <connection-customization> section of your saved data source  file. For reference, see the Sample SQLite TDC file in the Attachments section of this article or review the Tableau Online Help which reviews the contents of the TDC file.  Each TDC file has this basic structure:
<connection-customization class=DSCLASS enabled='true' version='10.0'>
    <vendor name=VENDOR />
    <driver name=DRIVER />
        <customization name='CAP_FAST_METADATA' value='yes'/>

           2. Name the file odbc-<datasource>.tdc and save it to the following location:

For Windows:

In Tableau Server:

Program Files\Tableau\Tableau Server\packages\bin.<build number>

Or it can be saved in:

ProgramData\Tableau\Tableau Server\data\tabsvc\vizqlserver\Datasources

If you are using Tableau Prep Conductor, then you will need to additionally place a copy of the TDC file in:

ProgramData\Tableau\Tableau Server\data\tabsvc\flowprocessor\Datasources

To save the file, you must be a Windows Administrator on the server computer.

For Linux:


If using Tableau Prep Conductor:


Note: The file must be saved using a .tdc extension, but the name does not matter. The .tdc file must be saved on all server nodes for consistent behavior.
3. Restart Tableau Server to apply the change.

4. Test making a connection to the published data source specified by the new TDC file using web authoring as described in the Tableau Online Help or connect to a published data source with Tableau Desktop.

5. Go to and open the Tableau Server log file, and look for a record similar to the example below to verify that this customization file was applied to your new connection. The below sample is for SQLite.
C:\ProgramData\Tableau\Tableau Server\data\tabsvc\logs\vizqlserverFound matching TDC 'C:\\ProgramData\\Tableau\\Tableau Server\\data\\tabsvc\\logs\\vizqlserver\\Datasources\\odbc-sqlite.tdc for class='genericodbc', vendor='SQLite', and driver='SQLite3 ODBC Driver'

Additional Information

  • A .tdc file must be placed on each computer running vizqlserver or backgrounder (if applicable for extract refreshes).
  • When using a TDC file, the bin directory is checked first, and then the Datasources directory.
  • A .tdc file in the Datasources directory will override one in the bin directory.
  • A backup does not back up .tdc files.
  • A restore deletes existing .tdc files.
  • A .tdc file in the bin folder will not be retained across an upgrade because the bin directory is removed during uninstall.
  • A .tdc file in the Datasources folder will not be retained across upgrades because a restore is part of the upgrade process.
  • The .tdc file used in Tableau Desktop should be uploaded to Tableau Server without changes.  Non-matching .tdc files will cause errors and will not work correctly.

To test using the sample SQLite TDC file, follow the steps here.
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