On Tue, 2011-10-25 at 19:27 +0200, Florian Pflug wrote: > Assume, for example, that the postgres mailing list archive search used > tsearch (which I think it does, but I'm not sure). It'd then probably make > sense to add "postgres" to the list of stopwords, because it's bound to > appear in nearly every mail. But wouldn't you want searched which include > 'postgres*' to turn up empty? Quite certainly not.
That improves recall for "postgres:*" query and certainly doesn't help other queries like "post:*". But more importantly it affects precision for all queries like "a:*", "an:*", "and:*", "s:*", 't:*', "the:*", etc (When that is the only search it also affects recall as no row matches an empty tsquery). Since stopwords are smaller, it means prefix search for a few characters is meaningless. And I would argue that is when the prefix search is more important -- only when you know a few characters. -Sushant. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
