separate user for the frontend and the wallet #25

Functions that do inserts can do something like `insert into table select input_var where a_id > 0` but maybe PL/pgSQL would be a better choice.

I agree.

This might work but how would we deal with foreign key constraints?

If we change user_id 0 to null, then we can't use user_id as a primary key.

I don't know. Is there extra overhead with PL/pgSQL vs. SQL?