And on some platforms, like OpenVMS, async IO isn't an option -- it's the default. :)
Rich OpenVMS bigot, despite not having any more VMS boxen around... :( Rich Jesse System/Database Administrator [EMAIL PROTECTED] Quad/Tech Inc, Sussex, WI USA > -----Original Message----- > From: Tanel Poder [mailto:[EMAIL PROTECTED] > Sent: Friday, September 19, 2003 11:05 AM > To: Multiple recipients of list ORACLE-L > Subject: Re: asynch I/O > > > I just hit a description of async IO in Oracle docs, it is very simply > described there: > > <quote> > With synchronous I/O, when an I/O request is submitted to the > operating > system, the writing process blocks until the write is > confirmed as complete. > It can then continue processing. > Asynchronous I/O allows a process to submit an I/O request but to then > continue processing. It may then check on the result of the > I/O at a later > time. It is also possible to submit several I/O requests and > then collect > the status of those requests at a later time, thus allowing > the operating > system to parallelize any of those I/O operations, where > possible. Parallel > processing can reduce the overall time to complete an operation. > > Consider an extreme example: Imagine you want to write out > four data blocks > to four different files. With synchronous I/O you must submit > block 1, wait, > submit block 2, wait, submit block 3, wait, submit block 4, > and wait. With > asynchronous I/O, you can submit blocks 1, 2, 3, and 4 and > then wait for all > four blocks to complete. Because you gave the operating > system all four I/O > requests at once, it can act on all the requests in parallel. > The total > response time is only the duration of the longest I/O of the > four, rather > than the sum of all four I/O durations. > > </quote> > > Tanel. > > ----- Original Message ----- > > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> > Sent: Friday, September 19, 2003 5:24 PM > > > > Ryan, > > > > You can have separate mount points from your server's > perspective, but > once you get into the NetApp it's just a pool of disk drives that are > allocated as necessary by their WAFL (Write Anywhere File > Layout) system. > Therefore in reality you get zero benefit. > > > > Dick Goulet > > Senior Oracle DBA > > Oracle Certified 8i DBA > > > > -----Original Message----- > > Sent: Thursday, September 18, 2003 10:10 PM > > To: Multiple recipients of list ORACLE-L > > > > > > Could you clarify something for me? Are you saying that if I have a > variety > > of 'mounts' on our netapp > > > > say > > > > /mnt1 > > /mnt2 > > > > I would not benefit by putting my datafiles on seperate > ones? I thought > that > > is where my I/O waits are coming from. Since we have all of > our datafiles > in > > the same directory? -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Jesse, Rich INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
