Simon Riggs wrote: > On Mon, 2004-11-22 at 23:37, Greg Stark wrote: > > Simon Riggs <[EMAIL PROTECTED]> writes: > > > > > - Find a way to reduce rotational delay when repeatedly writing last WAL > > > page > > > > > > Currently fsync of WAL requires the disk platter to perform a full > > > rotation to fsync again. One idea is to write the WAL to different > > > offsets that might reduce the rotational delay. > > > > Once upon a time when you formatted hard drives you actually gave them an > > interleave factor for a similar reason. These days you invariably use an > > interleave of 1, ie, store the blocks continuously. Whether that's because > > controllers have become fast enough to keep up with the burst rate or > > because > > the firmware is smart enough to handle the block interleaving invisibly > > isn't > > clear to me. > > > > I wonder if formatting the drive to have an interleave >1 would actually > > improve performance of the WAL log. > > > > It would depend a lot on the usage pattern though. A heavily used system > > might > > be able to generate enough WAL traffic to keep up with the burst rate of the > > drive. And an less used system might benefit but might lose. > > > > Probably now the less than saturated system gets close to the average > > half-rotation-time latency. This idea would only really help if you have a > > system that happens to be triggering pessimal results worse than that due to > > unfortunate timing. > > I was asking whether that topic should be removed, since Tom had said it > had been rejected....
The method used to fix it was rejected, but the goal of making it better is still a valid one. -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (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
