The MySQL driver performed well. It was able to answer 689 Queries Per Second, which means the SQL server itself was handling about 2067 queries every second.

The DLZ configuration below was used during testing. This configuration provides optimum performance by using the simplest lookup query possible. This lookup query does not wrap DNS TXT records in double quotes, as TXT records should be stored in the database with double quotes already. The DNS SOA record fields are also returned in each query because doing so is faster than performing a check to determine what type of DNS record is returned in the query itself using case statements.

dlz "mysql zone" {
   database "mysql
      {host=localhost dbname=dns_data ssl=false}
      {select zone from dns_records where zone = '%zone%'}
      {select ttl, type, mx_priority, data, resp_person, serial, refresh,
retry, expire, minimum from dns_records where zone ='%zone%' and host = '%record%'}";
};