Greg Smith wrote:
On Tue, 9 Sep 2008, Amber wrote:
I read something from
http://monetdb.cwi.nl/projects/monetdb/SQL/Benchmark/TPCH/index.html
saying that PostgreSQL can't give the correct result of the some
TPC-H queries
Jignesh Shah at Sun ran into that same problem. It's mentioned
briefly in his presentation at
http://blogs.sun.com/jkshah/entry/postgresql_east_2008_talk_postgresql
on pages 26 and 27. 5 of the 22 reference TCP-H queries (4, 5, 6, 10,
14) returned zero rows immediately for his tests. Looks like the
MonetDB crew is saying it does that on queries 4,5,6,10,12,14,15 and
that 20 takes too long to run to generate a result. Maybe 12/15/20
were fixed by changes in 8.3, or perhaps there were subtle errors
there that Jignesh didn't catch--it's not like he did a formal
submission run, was just kicking the tires. I suspect the difference
on 20 was that his hardware and tuning was much better, so it probably
did execute fast enough.
While some of the MonetDB bashing in this thread was unwarranted, it
is quite inappropriate that they published performance results here.
Would be nice if someone in the community were to grab ahold of the
TPC-H problems and try to shake them out.
Hmm This is the second time MonetDB has published PostgreSQL numbers. I
think I will try to spend few days on TPC-H again on a much smaller
scale (to match what MonetDB used) and start discussions on solving the
problem.. Keep tuned.
Regards,
Jignesh
