On Wed, Nov 16, 2011 at 4:59 PM, Tomas Vondra <tv@xxxxxxxx> wrote: > But you're right - you're not bound by I/O (although I don't know what are > those 15% - iowait, util or what?). The COUNT(DISTINCT) has to actually > keep all the distinct values to determine which are actually distinct. Actually I meant to comment on this, he is IO bound. Look at % Util, it's at 99 or 100. Also, if you have 16 cores and look at something like vmstat you'll see 6% wait state. That 6% represents one CPU core waiting for IO, the other cores will add up the rest to 100%. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
