[dhd415]

PostgreSQL, for better or worse, doesn't have pluggable storage engines. There's some discussion on their dev mailing list about the possibility of adding that capability in PG10, though: http://postgresql.nabble.com/Pluggable-storage-td5916322.htm...

Some earlier (2013) discussion on the same topic: https://wiki.postgresql.org/wiki/2013UnconfPluggableStorage

[asah]

tl;dr: Foreign Data Wrappers (FDW) provide 99% of the same functionality, but with even more flexibility incl smart query optimizer support.

[pgaddict]

That is far too optimistic, IMHO.

FDW are a great way to access external data sources, but it lacks proper support for visibility and transactions, and so on. Also, the FDW API follows the "tuple at a time" execution model, which prevents a lot of optimizations in the upper part of the stact (vectorized execution etc.).

There are several products using FDWs to change storage, but I'd call it a misuse of a feature designed for very different purpose.

IMHO it's hardly a way forward without significant changes/improvements (which may happen, I don't know).