Comment Re:What about keyword searches? (Score 2) 266
Speaking from knowledge of search engine indexing; you can't search on regular expressions because the search index is heavily heavily optimised and the only way to search for a regex would be to generate all the possible expansions and search for them individually. You could do it, it would just fuck up everyone's processes.
If you've done anything with SQL think about how slow wildcard text searches are compared to an indexed primary key search, then multiply by a couple of orders of magnitude since search engines throw away generality for extreme performance on a particular kind of search.