Using RStudio Server with PostgreSQL Database

#1
I have installed a RStudio Server on Ubuntu OS machine and PostgreSQL data base for ingesting data. I am able to connect to DB using RPostgreSQL package. I have been able to successfully execute many SQL queries on the data.

Can I analyze the data without ingesting data in RStudio. How do I reference to the variables which are on Database. Are there special set of commands for the same?

Bharat