If I'm just doing DB schema documentation, and I don't need to integrate that documentation into broader technical documentation, schemaspy is the tool I reach for.
My impression is that the maintainers are Oracle-centric (I don't interact with the project with any regularity, so this could be mistaken), but I use this with PostgreSQL and have been quite pleased.
http://schemaspy.org/
My impression is that the maintainers are Oracle-centric (I don't interact with the project with any regularity, so this could be mistaken), but I use this with PostgreSQL and have been quite pleased.