On Wed, Dec 14, 2005 at 08:28:56PM +1300, Mark Kirkwood wrote: > Another interesting thing to try is rebuilding the database ufs > filesystem(s) with 32K blocks and 4K frags (as opposed to 8K/1K or > 16K/2K - can't recall the default on 4.x). I found this to give a factor > of 2 speedup on random disk access (specifically queries doing indexed > joins).
Even if you're doing a lot of random IO? I would think that random IO would perform better if you use smaller (8K) blocks, since there's less data being read in and then just thrown away that way. > Is it mainly your 2 disk machines that are IOPS bound? if so, a cheap > option may be to buy 2 more cheetahs for them! If it's the 4's, well how > about a 2U U320 diskpack from whomever supplies you the Supermicro boxes? Also, on the 4 drive machines if you can spare the room you might see a big gain by putting the tables on one mirror and the OS and transaction logs on the other. -- Jim C. Nasby, Sr. Engineering Consultant [EMAIL PROTECTED] Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
