On Thu, Sep 4, 2008 at 5:11 PM, Tom Lane <[EMAIL PROTECTED]> wrote: > So my thinking right now is that we should just test this patch as-is. > If it doesn't show really horrid performance when there are lots of > hash key collisions, we should forget the store-both-things idea and > just go with this.
Ok let me know if this is to naive of an approach or not hitting the right cases you want tested. create table hash_a (same text, uniq text); insert into hash_a (same, uniq) select 'same', n from generate_series(0, 5000) as n; create table hash_b (uniq text); insert into hash_b (uniq) select n from generate_series(5000, 10000) as n; pgbench -c 1 -t 100 -n -f of the following hash_same.sql: set enable_seqscan to off; set enable_mergejoin to off; select 1 from hash_a as a inner join hash_a as aa on aa.same = a.same; hash_uniq.sql: set enable_seqscan to off; set enable_mergejoin to off; select 1 from hash_a as a inner join hash_b as b on b.uniq = a.uniq; -- Sent via pgsql-patches mailing list (pgsql-patches@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-patches