Foreign Data Wrapper

https://riptutorial.com/postgresql/example/29417/foreign-data-wrapper

To access complete schema of server db instead of single table. Follow below steps:

1. Create EXTENSION :

    CREATE EXTENSION postgres_fdw;

2. Create SERVER :

    CREATE SERVER server_name FOREIGN DATA WRAPPER postgres_fdw OPTIONS (host 'host_ip', 
    dbname 'db_name', port 'port_number');

3. Create USER MAPPING:

    CREATE USER MAPPING FOR CURRENT_USER
    SERVER server_name
    OPTIONS (user 'user_name', password 'password');

4. Create new schema to access schema of server DB:

   CREATE SCHEMA schema_name;

5. Import server schema:

     IMPORT FOREIGN SCHEMA schema_name_to_import_from_remote_db
     FROM SERVER server_name
     INTO schema_name;

6. Access any table of server schema:

    SELECT * FROM schema_name.table_name; 

This can be used to access multiple schema of remote DB.