PostgreSQL HSTORE type should be marked hashable = False
HSTORE type returns
dict objects, which are not hashable, so it should not have the default
hashable = True. Fixing this (setting
hashable = False) allows columns of this type to be loaded along with ORM entities in a
Query as per
Will attach a totally trivial patch that does this, breaking no tests, and applies cleanly on rel_0_8, rel_0_9 and master.