From the article at:
http://www.irc101.org/news.php?id=333
"Second, after over a year of development, the new version of the Q
channel service is now in the final phases of testing. Even though the
new service was nearly complete over 7 months ago, mySQL performance
issues surfaced during intensive testing. These issues eventually forced
QuakeNet dev-com to change the database engine of choice to pgSQL,
requiring a complete rewrite of every database-related function in the
new Q."
Gavin