Alex Turner wrote: > Does it really matter at which end of the cable the queueing is done > (Assuming both ends know as much about drive geometry etc..)?
Good question. If the SCSI system was moving the head from track 1 to 10, and a request then came in for track 5, could the system make the head stop at track 5 on its way to track 10? That is something that only the controller could do. However, I have no idea if SCSI does that. The only part I am pretty sure about is that real-world experience shows SCSI is better for a mixed I/O environment. Not sure why, exactly, but the command queueing obviously helps, and I am not sure what else does. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
