Just as another data point we had to tweak some searches where our service desk had used “LIKE” in a large number of ANDed search terms. Those “LIKE”s could easily be replaced with straight equality, and then the whole thing speeded up (as in stop taking the RT instance in to slow-motion mode for a minute or two each time they ran the search). I also knocked up a little local callback that quietly converted “LIKE” to “SHALLOW LIKE” which also helped.