Brian Crowell <brian@xxxxxxxxxx> writes: > Which says to me coalesce has a selectivity. Well, the point is you're just getting a default selectivity estimate for the "acc.rule_set_id = coalesce(...anything...)" condition. The planner is smarter about plain "x = y" join conditions: it looks up the column stats for x and y and determines the probability of equality. In principle I guess we could somehow merge the stats of y and z when looking at a "coalesce(y, z)" expression, but I'm not sure how that would work exactly. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
