At least this type-ref query is unreasonably slow, about a minute long: http://dxr.allizom.org/search?q=type-ref%3Adrop&tree=mozilla-central Take a look at the query plan. Maybe we're missing indices or something.
At the moment it's only 7 seconds for me. However I find that a bit slow, but if was bug 847580 fixed, the result might be good enough.
7 seconds is still pretty ridiculous. We're almost certainly doing something dumb in the DB. :-)
Down to 1.3 seconds now, but there's still a 38,000-row table scan in there: http://dxr.allizom.org/mozilla-central/search?tree=mozilla-central&q=type-ref%3Adrop&redirect=true&explain=true