Support Postgresql Schema for PostGIS DB
A Postgres database contains one or more named schemas, which in turn contain tables. Default is the public schema. Especially with PostGIS the use of schemas is recommended practice (all PostGIS functions and ref to PostGIS libs reside in the public schema, think of issues when making native dumps). The current GHC implementation does not support PG schemas yet.
PG Schemas with SQLAlchemy requires special handling, i.e. there is (AFAIK) no provision in the DB URI, provided in GHC via the SQLALCHEMY_DATABASE_URI config setting. See for example here.
Possibly we can extend the SQLALCHEMY_DATABASE_URI with a schema or have a schema variable.
With JDBC this notation can be used:
jdbc:postgresql://localhost:5432/mydatabase?searchpath=public,myschema.
Not sure if this will work with SQLAlachemy.
Removing Milestone, this issue appears to be quite involved: not just SQLAlchemy-related changes needed but also Alembic upgrades.