I've implemented a completely new Redis FDW module which has little to do with github.com/pg-redis-fdw/redis_fdw; although I did take some inspiration from in on how the tables were to be designed but most I got from looking at the oracle-fdw.
My redis-fdw implementation supports read and write to the Redis backend, so you can do insert, update, and delete. e.g. you can define a hash table as:
table rhash (
key text,
field text,
value test, expiry int
) server redserver options(tabletype 'hash');
and do: select * from rhash where key = 'foo' and field = 'bar';
update rhash set value = 'bahbah' where key = 'foo' and field = 'bar'; delete from rhash where key = 'foo' and field = 'bar';
I need someone experienced with postgresql's internals for FDWs to review my code and let me know if I've done something wrong or where I can optimize it a little more. Once it has been reviewed, I'll post it up and announce it on my github account for public consumption. But for now I want to make sure that the code is correct.
There are some functions (Explain* and costs) which I know I haven't implemented properly so assistance with that is also appreciated.