I'm - not for the first time bemused - I wonder if anyone can (after fighting past the screwed up formatting that blogger gave me) shed light on the results that I have on my site for running identical SQL on identical hardware (the same machine actually) under Windows XP sp2 and Fedora Core 3 linux. (incidentally FC3 passed the certified os checks on install). briefly the test is create a table with 20k rows. insert into the table all the rows from itself 6 times tune based on the response time (I've used tkprof to generate the response time profile). My linux box seems to be stuck waiting on log_buffer space and whilst throwing memory at it has helped (I've gone as high as 8mb log buffer and to my surprise got some marginal improvement over the 1mb I've documented) it is still half the speed of the same hardware running windows. some mistake surely. My kernel parameters are kernel.shmall = 2097152 kernel.shmmax = 2147483648 kernel.shmmni = 4096 kernel.sem = 250 32000 100 128 fs.file-max = 65536 net.ipv4.ip_local_port_range = 1024 65000 because I followed John Smiley's article for the install (http://www.oracle.com/technology/pub/articles/smiley_10gdb_install.html) -- Niall Litchfield Oracle DBA http://www.niall.litchfield.dial.pipex.com -- //www.freelists.org/webpage/oracle-l