file_fdw extension

The file_fdw module provides the foreign-data wrapper file_fdw, which can be used to access data files in the server's file system, or to execute programs on the server and read their output.

To enable the extension:

CREATE EXTENSION file_fdw;

Create a foreign server:

CREATE SERVER my_server FOREIGN DATA WRAPPER file_fdw;

Now, you can create foreign tables that access data from files. For example:

CREATE FOREIGN TABLE employees (id int, employee_name varchar) SERVER my_server OPTIONS (filename 'employees.csv', format 'csv');

You can execute SELECT statements on the foreign tables to access the data in the corresponding files.