Use SQL commands such as INSERT and SELECT to query a readable external table, the same way that you query a regular database table. For example, to load travel expense data from an external table, ext_expenses, into a database table, expenses_travel:
=# INSERT INTO expenses_travel
SELECT * from ext_expenses where category='travel';
To load all data into a new database table:
=# CREATE TABLE expenses AS SELECT * from ext_expenses;
Parent topic: Loading and Unloading Data
