I prefer and use the knot DNS server for authoritative DNS (and either knot-resolver or Unbound for caching DNS servers) myself: it is quite feature-rich, including DNSSEC, RFC 2136 support, an easy master-slave setup. Apparently it does support database-based configuration and zone definitions, too, but I find file-based storage to be simpler.
The database for configuration and zone data is strictly internal and not tied to an external relational database, like what's shown in the article.