On Tue, Dec 10, 2013 at 2:38 PM, Andres Freund <and...@2ndquadrant.com> wrote: > It's very hard to see where you should spend efforts when every "logical > query" is split into hundreds of pg_stat_statement entries. Suddenly > it's important whether a certain counts of parameters are more frequent > than others because in the equally distributed cases they fall out of > p_s_s again pretty soon. I think that's probably a worse than average > case, but certainly not something only I could have the bad fortune of > looking at.
Another problem is that creating a new entry is relatively expensive, because we need to acquire an exclusive lock to do so. If there was a lot of churn, I'd worry that the performance overhead of pg_stat_statements. It could be quite a lot higher than necessary. -- Peter Geoghegan -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
