Boszormenyi Zoltan írta: > Boszormenyi Zoltan írta: > >> Boszormenyi Zoltan írta: >> >> >>> Heikki Linnakangas írta: >>> >>> >>> >>>> On 26.10.2010 18:34, Boszormenyi Zoltan wrote: >>>> >>>> >>>> >>>>> thank you very much for pointing me to dynahash, here is the >>>>> next version that finally seems to work. >>>>> >>>>> Two patches are attached, the first is the absolute minimum for >>>>> making it work, this still has the Tree type for canon_pathkeys >>>>> and eq_classes got the same treatment as join_rel_list/join_rel_hash >>>>> has in the current sources: if the list grows larger than 32, a hash >>>>> table >>>>> is created. It seems to be be enough for doing in for >>>>> get_eclass_for_sort_expr() >>>>> only, the other users of eq_classes aren't bothered by this change. >>>>> >>>>> >>>>> >>>> That's better, but can't you use dynahash for canon_pathkeys as well? >>>> >>>> >>>> >>> Here's a purely dynahash solution. It's somewhat slower than >>> the tree version, 0.45 vs 0.41 seconds in the cached case for the >>> previously posted test case. >>> >>> >>> >> And now in context diff, sorry for my affection towards unified diffs. :-) >> >> > > A little better version, no need for the heavy hash_any, hash_uint32 > on the lower 32 bits on pk_eclass is enough. The profiling runtime > is now 0.42 seconds vs the previous 0.41 seconds for the tree version. > > Best regards, > Zoltán Böszörményi >
Btw, the top entries in the current gprof output are: Each sample counts as 0.01 seconds. % cumulative self self total time seconds seconds calls ms/call ms/call name 19.05 0.08 0.08 482 0.17 0.29 add_child_rel_equivalences 11.90 0.13 0.05 1133447 0.00 0.00 bms_is_subset 9.52 0.17 0.04 331162 0.00 0.00 hash_search_with_hash_value 7.14 0.20 0.03 548971 0.00 0.00 AllocSetAlloc 4.76 0.22 0.02 2858 0.01 0.01 get_tabstat_entry 4.76 0.24 0.02 1136 0.02 0.02 tzload This means add_child_rel_equivalences() is still takes too much time, the previously posted test case calls this function 482 times, it's called for almost every 10th entry added to eq_classes. The elog() I put into this function says that at the last call list_length(eq_classes) == 4754. Best regards, Zoltán Böszörményi -- ---------------------------------- Zoltán Böszörményi Cybertec Schönig & Schönig GmbH Gröhrmühlgasse 26 A-2700 Wiener Neustadt, Austria Web: http://www.postgresql-support.de http://www.postgresql.at/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
