Hi! On Nov 26, Mike Wexler wrote: > Sergei Golubchik wrote: > > Hi! > > > > I didn't test it yet. > > > > The one thing I can say just now that unlike natural language search > > code (as exists in MySQL in 3.23) it need not to build the complete list > > of matched documents in memory in advance. It means that with LIMIT it > > should be MUCH faster than the old code. Unfortunately, it also means > > that it does not "auto-magically" return documents with relevance > > decreased (without ORDER BY, that is). > > If I use ORDER BY relevance and LIMIT. Does it need to build the > complete list of documents in memory in advance? Or will it just build > enough to satisfy the limit constraints.
It will "build enough to satisfy the limit constraints", but with ORDER BY this "enough" is the complete list. If you want to get five rows with highest relevances MySQL will retrieve all the matching rows, sort them with relevance decreasing, and then return top five rows. But it should not be a big deal as for boolean searches there's no meaningful "relevance" anyway. It's boolean - true or false. Some floating point "relevance" is introduced to give a rough estimation of the number of words matched, but, in fact, all the rows in the result set are equally relevant to the query with relevance value TRUE. Regards, Sergei -- MySQL Development Team __ ___ ___ ____ __ / |/ /_ __/ __/ __ \/ / Sergei Golubchik <[EMAIL PROTECTED]> / /|_/ / // /\ \/ /_/ / /__ MySQL AB, http://www.mysql.com/ /_/ /_/\_, /___/\___\_\___/ Osnabrueck, Germany <___/ --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
