postgresql - Do local versions of postgres foreign data wrappers update automatically?

Question

Apologies if this is answered in the docs or somewhere else obvious, but I have just gone through the rigmorale of having to use postgres_fdw to get data from another database (quite different to the ease of MS SQL!)

I ran an IMPORT SCHEMA statement to get the foreign table/databse data into my working database. Will the data in this schema automatially update whenever the data in the foreign database updates or is this IMPORT SCHEMA a copy of the data?

Answer 1

A foreign table does not contain any data. Querying it will yield the current data in the remote table. Think of it as something like a view.

If you are talking about metadata changes (ALTER TABLE), the analogy to views is also helpful: such changes will not be reflected in the foreign table, and you need to run an ALTER FOREIGN TABLE statement.

Perhaps it would make sense to put the data for these databases in a single database in two different schemas.