Hi, On 2015-03-11 14:40:16 +0000, Andrew Gierth wrote: > An issue that comes up regularly on IRC is that text search queries, > especially on relatively modest size tables or for relatively > non-selective words, often misplan as a seqscan based on the fact that > to_tsvector has procost=1.
I've also seen this regularly outside IRC. > Clearly this cost number is ludicrous. Yea. > Getting the right cost estimate would obviously mean taking the cost of > detoasting into account Well, that's not done in other cases where you could either, so there's precedence for being inaccurate ;) > ,but even without doing that, there's a strong > argument that it should be increased to at least the order of 100. > (With the default cpu_operator_cost that would make each to_tsvector > call cost 0.25.) 100 sounds good to me. IIRC that's what has been proposed before. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
