Heikki Linnakangas escribió: > Oprofile suggests that most of the time is actually spent in > pgstat_vacuum_stat. And more precisely in pstat_collect_oids, which is > called by pgstat_vacuum_stat.
Hmm, that routine is expensive. Calling it for every vacuum is not good :-( Fortunately, autovacuum calls it only once per worker run rather than once per table. That limits the damage. I wonder if we could do better in pgstat_vacuum_stat; for example, scanning all of pg_proc is useless most of the time, and then it has to fill and seq-search a hash table with all the builtins which will never get dropped. I wonder if we could use pg_depend instead of pg_proc, and skip pinned functions, for example. In the end, it would be better if this function was not called at all for user-invoked vacuum, and have autovacuum handle it. However, that doesn't work for people who disable autovacuum. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
