Dear all,

I'm running MonetDB (Dec2011-SP2) on Sparc Solaris 10 u9. I'm testing the TPC-H queries using SF10 and SF100 as the scale factors. My machine has 4 cores and 32GB of RAM and my farm is on a disk array.

Unfortunately, there are some queries (e.g., Qry 7, 8, 9) that enters into phase in which the User/System time is 4% to 21% for a couple of minutes. Interestingly, the same issue doesn't show up on a Linux machine with a similar setup and the queries' system time is pretty low (<5%).

Interestingly, vmstat output doesn't show any disk activity during the phase where the process is just in system, only there are high values on "re" and "mf" fields. There is no swapping going on ("po" and "pi" values are 0 in vmstat).

These are the parameters of the DB:

type default database
shared default yes
nthreads default 4
optpipe default_pipe
master default no
slave default <unknown>
readonly default no
nclients default 64

The way that I test the query is by running just one at a time. How can I mitigate this OS time?

Thanks in advance,
Javier