mySQL fulltext or vB built in?
 

As our postindex table is over 39 million rows big and search sometimes crashes (memory exhausted) I wonder which search method would be less server intensive?

As the mysql fulltext search is built in, I would assume that that should be able to handle some big loads, allthough I don't know much of the technical stuff.

I've heard though that the current mysql fulltext search built into vB isn't all too optimised yet.

it's not too optimized right now, but iirc vb.com is using it already.

I'd say that mysqls build in feature is optimized enough to use it, so switch over ;)