Newt DB, the amphibious database
In Python: enjoy the ease of working with your data as ordinary objects in memory.
Data are moved in and out of memory as needed, so databases can be as large as needed.
In Postgres: index and search your data using PostgreSQL, from within your application and externally.
Within your application, search results may be returned as application objects, or as data, depending on your needs.
Transactional and built on mature technology for reliability.