The production database for MGD is a highly normalized relational database hosted on a PostgreSQL server behind a firewall. The production database is designed and optimized for data integration and incremental updating and is not directly accessible by the public. The public web interface is backed by a combination of a highly denormalized databases (also in PostgreSQL) and Solr/Lucene indexes, designed for high performance query and display in a read-only environment. The front-end data stores are refreshed from the production database once a week. The separation of public and production architectures provides a large measure of flexibility in project planning, as either side can (and often does) change without affecting the other.
