In some cases, it can make sense to read a file from a disk and expose it to PostgreSQL as a table. This is exactly what you can achieve with file_fdw extension. The idea is to have a module that allows you to read data from a disk and query it using SQL.
Installing the module works as expected:
CREATE EXTENSION file_fdw;
In the next step, we create a virtual server:
CREATE SERVER file_server FOREIGN DATA WRAPPER file_fdw;
The file_server is based on the file_fdw extension foreign data wrapper, which tells PostgreSQL how to access the file.
To expose a file as a table, the following command can be used:
CREATE FOREIGN TABLE t_passwd ( username text, passwd text, uid int, gid int, gecos text, dir text, ...
