Hi Sachin, I'm not sure what you mean with import extension approach because if you don't have PostgreSQL as your default persistence provider you must have setup the database connection using the extension.
But like you already said you have a working connection to PostgreSQL you can simply create scripts as SQL Query/Command to query the data which can be pulled into your Mashup.
Thanks Sushant for quick reply.
Creating a script as SQL Query to query the data and bind that data to mashup worked out. I created one service in thing which will query the data and return the result. I bonded that service to Clicked function of button on mashup and it worked out. I can see data on mashup
Thanks a lot.