I went through this thread again, and noticed something that no one seems to have remarked on at the time: the vmstat numbers near the bottom of this post http://archives.postgresql.org/pgsql-general/2008-01/msg00161.php show close to 100% I/O wait time (either that or 50% idle 50% I/O wait, which I suspect is an artifact). We subsequently concluded that the "SELECT" side of the INSERT/SELECT command is not where the problem is, so all the cycles are going into the actual row insertion part. I don't know of any reason to think that insertion is slower in 8.3 than it was in 8.2, and no one else has reported anything of the sort. So I'm leaning to the idea that this suggests some kind of misconfiguration of the disk setup in Clodoaldo's new server. There was some earlier discussion about not having the RAID configured right: http://archives.postgresql.org/pgsql-general/2008-01/msg00169.php I'm thinking it's still not right :-( but have no real expertise at diagnosing such problems. Anyone? regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings