Came across a blog from Ovid, one of the Perl gurus at BBC.
http://use.perl.org/~Ovid/journal/35752?from=rssQuote
"They're not kidding, either.
Subquery optimization in MySQL is terribly broken, as we've discovered today. We have Matt Trout in for some consulting and even ridiculously stupid subqueries have terrible query plans, forcing us to to consider nasty workarounds, one of which is called "PostgreSQL"."
Even though he counts PostgreSQL as one of th enasty workarounds, maybe we should give them a helping hand?
Wenjian
