If you don't ask :) I've never worked on a large-scale text indexing so it doesn't have to be a particularly sophisticated insight. I'm speculating that the ma

If you don't ask :) I've never worked on a large-scale text indexing so it doesn't have to be a particularly sophisticated insight. I'm speculating that the majority of uses cases need some kind of work equivalency, so the major index is built that way. Whether that's just for the search terms of the average user, or ranking/clustering used to derive which pages are important. Then any additional indexes is a trade off with the magnitude of resources it would consume.