This post includes instructions on how to locate Tableau Server's pgAdmin III PostgreSQL tool to query the workgroup database. This This tool is installed with your Tableau Server install.
On your Tableau Server, go to C:\Program Files\Tableau\Tableau Server\8.3\pgsql\bin\pgAdmin3.exe to open the pgAdmin PostgreSQL tool.
Connect to your server, then navigate to: Databases->workgroup->Schemas->public->Tables
Goodbye are the days of connecting Tableau directly to PostgreSQL, or looking at online documentation to get column definitions. And, no added tool needed to install.
Retrieving data ...