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, I wonder is there any official statements about this, because it will affect our plane of using PostgreSQL as an alternative because it's usability. BTW I don't think PostgreSQL performances worse because the default configuration usually can't use enough resources of the computer, as as memory.