<firstterm>foreign data wrapper</firstterm>. A foreign data wrapper is a

library that can communicate with an external data source, hiding the

details of connecting to the data source and fetching data from it. There

is a foreign data wrapper available as a <file>contrib</file> module,

is a foreign data wrapper available as a <filename>contrib</> module,

which can read plain data files residing on the server. Other kind of

foreign data wrappers might be found as third party products. If none of

the existing foreign data wrappers suit your needs, you can write your