On Wed, Oct 4, 2017 at 9:49 AM, Michael Paquier <michael.paqu...@gmail.com> wrote: > I am still on the learning curve with pg_stat_statements... This still > does not look complete to me. pgss_hash_fn only makes use of the last > four bytes of the query ID. What about computing the hash using as > also the first four bytes? With the current code, if the last four > bytes of two queries match then they would be counted together looking > at pgss_store().
Not really; dynahash won't merge two keys just because their hash codes come out the same. But you're right; that's probably not the best way to do it. TBH, why do we even have pgss_hash_fn? It seems like using tag_hash would be superior. > I have spotted as well this comment in pg_stat_statements.c: > /* Increment the counts, except when jstate is not NULL */ > if (!jstate) > I think that this should be "when jstate is NULL". I think that you're right, but that's unrelated to this patch. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers