Curt Sampson wrote: > > On Tue, 23 Apr 2002, mlw wrote: > > > > On a system that has neither read-ahead nor sorting of I/O requests, > > > yes. Which systems are you using that provide neither of these > > > facilities? > > > > This only happens if the OS can organize the I/O requests in such a manner. It > > is a non-trivial function. > > Well, if you call less than 200 lines of code (including lots of > comments), "non-trivial," yes. Have a look at NetBSD's > src/sys/kern/subr_disk.c for one example implementation. > > But trivial or not, if all operating systems on which Postgres runs > are doing this, your point is, well, pointless. So, once again, which > systems are you using that do *not* do this?
I am not arguing about whether or not they do it, I am saying it is not always possible. I/O requests do not remain in queue waiting for reordering indefinitely. ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
