Jeffrey, > I guess database reads are different, but I remain unconvinced that they > are *fundamentally* different. After all, a tab-delimited file (my sort > workload) is a kind of database.
Unfortunately, they are ... because of CPU overheads. I'm basing what's "reasonable" for data writes on the rates which other high-end DBs can make. From that, 25mb/s or even 40mb/s for sorts should be achievable but doing 120mb/s would require some kind of breakthrough. > On a single disk you wouldn't notice, but XFS scales much better when > you throw disks at it. I get a 50MB/sec boost from the 24th disk, > whereas ext3 stops scaling after 16 disks. For writes both XFS and ext3 > top out around 8 disks, but in this case XFS tops out at 500MB/sec while > ext3 can't break 350MB/sec. That would explain it. I seldom get more than 6 disks (and 2 channels) to test with. -- --Josh Josh Berkus Aglio Database Solutions San Francisco ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
