I am using MonetDB for benchmarking on the TPC-H workload. I have successfully run queries 1, 3 and 10. However, when I try to run query 5: select n_name, sum(l_extendedprice * (1 - l_discount)) as revenue from customer, orders, lineitem, supplier, nation, region where c_custkey = o_custkey and l_orderkey = o_orderkey and l_suppkey = s_suppkey and c_nationkey = s_nationkey and s_nationkey = n_nationkey and n_regionkey = r_regionkey and r_name = 'ASIA' and o_orderdate >= date '1994-01-01' and o_orderdate < date '1994-01-01' + interval '1' year group by n_name order by revenue desc; it takes about two (2) hours to evaluate it. It is obvious that the query cannot be executed inside the main memory, so the system thrashes through paging. Still, this behaviour does not appear for the rest of the queries, as they are computed within one or two seconds. In all cases, the results are correct. The specifications of my system are: Processor: Intel Core 2 Duo @ 1.86 Mhz RAM: 2 Gb Operating System: Linux Ubuntu Gutsy 7.10 MonetDB version: Mserver5 (recently downloaded from your site). Can you give me some indications about why this query takes too long and how can I bypass this response delay? Thanks.