Error "Channel is in state TRANSIENT_FAILURE" connecting to PostgreSQL

Option 1

1. In the Windows search box, type Internet Options and hit Enter.
2. Open the Connections tab and click LAN settings.
3. In the Proxy Server section, click Advanced to add the following exception: 127.0.0.1,localhost,database address.
   • NOTE: do not use wildcards (*) - specify the full IP address and/or FQDN.
4. Click OK to close the window.

Option 2

Delete the environment variables HTTP_PROXY and HTTPS_PROXY. 

Option 3

Add an environmental variable NO_PROXY to bypass a proxy server.

1. On the Windows search box, type sysdm.cpl and hit Enter.
2. Open the Advanced tab and click Environmental Variables.
3. In the system variables section, click New to add the following environmental variable:
   • Variable: NO_PROXY
   • Value: 127.0.0.1;localhost;database address.
     • NOTE: do not use wildcards (*) - specify the full IP address and/or FQDN.
4. Click OK to close the window. 

Set an exception so that the proxy server will not be used for communicating with localhost and the database.

Note: Similar error may occur due to the lack of Java heap space in some environments.

Tableau Desktop Error ​"channel is in state TRANSIENT_FAILURE" when trying to create an extract with an OData table containing a large number of records