MediaWiki uses a fairly typical mostly-normalized relational design. You couldn't easily port it to a document store. http://upload.wikimedia.org/wikipedia/co

MediaWiki uses a fairly typical mostly-normalized relational design. You couldn't easily port it to a document store. http://upload.wikimedia.org/wikipedia/commons/3/33/MediaWiki_database_schema_1-19_%28r102798%29.svg http://upload.wikimedia.org/wikipedia/commons/3/33/MediaWiki... Also, most MediaWiki installs use plugins, and those plugins often create their own database tables. So RDBMS is pretty much baked into the MediaWiki culture. However, MediaWiki is fairly well abstracted from any particular RDBMS implementation. Everything from creating tables to making a join is done through an API.