Back when Drupal 7 development opened, our database layer was in a sorry state. Based on PHP 3-era concepts it offered few features, but more importantly no one actually cared about it. On rare occasions we had a PostgreSQL maintainer for the PostgreSQL driver, but they had a tendency to disappear into the Interweb, never to be heard from again.
Boy what a difference a few months make! Not only is the new database layer moving along with a good head of steam, with an order of magnitude more features and now three database drivers in core, but as of earlier tonight we officially have no less than five people on the database maintenance team. From MAINTAINERS.txt: