Keeping two or more databases in sync might seem like a challenge but a dedicated application such as KS DB Merge Tools for PostgreSQL can be of great help in this case. As its name suggests, it is specifically designed for PostgreSQL databases, allowing you to synchronize and compare both schemas and data.

Side-by-side comparison of two PostgreSQL databases
Smartly enough, the layout of the main GUI is designed to facilitate side-by-side comparison between two databases. You can easily set up new database connections for each of the two panels and KS DB Merge Tools for PostgreSQL connects to PostgreSQL and starts populating the tables with objects, while also displaying totals, new and changed items in the database schema.