[kmike]

Originally Posted by Swamper

We're moving from a heavy modded 6.5+ million post vB2 to 3.6 in the coming weeks

Be warned that vB 3.6 is much more CPU demanding than vB2 (and even vB3), so you'd better beef up your web frontend(s) before the final switch.

Originally Posted by orban

Let's assume you have

thread1 - 100 times "word"
thread2 - 50 times "word"
thread3 - 10 times "word"
thread4-50 5 times "word"

A search for "word" will return us 2500 posts. BUT there are only 50 different threads.

If your limit is 1000 (like mine) this will only return like 30 threads. So you're missing out 20......I'm actually seeing this on very common words (when searching post and "show as threads").

Yes, that's exactly how vB search works in this specific case.
The solution? Don't search for the common words, it won't do any good in any case. Or better, narrow your search by adding more specific keywords.