Re: How to improve db performance with $7K?

От: Dave Held
Тема: Re: How to improve db performance with $7K?
Дата: ,
Msg-id: 49E94D0CFCD4DB43AFBA928DDD20C8F9026184B1@asg002.asg.local
(см: обсуждение, исходный текст)
Ответ на: How to improve db performance with $7K?  (Steve Poe)
Список: pgsql-performance

Скрыть дерево обсуждения

How to improve db performance with $7K?  (Steve Poe, )
 Re: How to improve db performance with $7K?  (Tom Lane, )
  Re: How to improve db performance with $7K?  (Steve Poe, )
 Re: How to improve db performance with $7K?  (Will LaShell, )
 Re: How to improve db performance with $7K?  ("Joshua D. Drake", )
  Re: How to improve db performance with $7K?  (Steve Poe, )
   Re: How to improve db performance with $7K?  (Bjoern Metzdorf, )
    Re: How to improve db performance with $7K?  (Josh Berkus, )
     Re: How to improve db performance with $7K?  (Steve Poe, )
      Re: How to improve db performance with $7K?  (Cott Lang, )
       Re: How to improve db performance with $7K?  (Steve Poe, )
        Re: How to improve db performance with $7K?  (Cott Lang, )
         Follow-Up: How to improve db performance with $7K?  (Steve Poe, )
          Re: Follow-Up: How to improve db performance with $7K?  (Thomas F.O'Connell, )
           Re: Follow-Up: How to improve db performance with $7K?  (Kevin Brown, )
            Re: Follow-Up: How to improve db performance with $7K?  ("Steinar H. Gunderson", )
            Re: Follow-Up: How to improve db performance with $7K?  (Thomas F.O'Connell, )
          Re: Follow-Up: How to improve db performance with $7K?  (Vivek Khera, )
           Re: Follow-Up: How to improve db performance with $7K?  (Will LaShell, )
     Re: How to improve db performance with $7K?  (Steve Poe, )
    Re: Follow-Up: How to improve db performance with $7K?  (PFC, )
     Re: Follow-Up: How to improve db performance with $7K?  ("Steinar H. Gunderson", )
   Re: How to improve db performance with $7K?  (PFC, )
    Re: How to improve db performance with $7K?  (Dave Cramer, )
     Re: How to improve db performance with $7K?  (Greg Stark, )
     Re: How to improve db performance with $7K?  (Alex Turner, )
      Re: How to improve db performance with $7K?  (Steve Poe, )
       Re: How to improve db performance with $7K?  (Alex Turner, )
        Re: How to improve db performance with $7K?  (Vivek Khera, )
         Re: How to improve db performance with $7K?  (Alex Turner, )
        Re: How to improve db performance with $7K?  (William Yu, )
         Re: How to improve db performance with $7K?  (Alex Turner, )
          Re: How to improve db performance with $7K?  (William Yu, )
           Re: How to improve db performance with $7K?  (Alex Turner, )
            Re: How to improve db performance with $7K?  ("Jim C. Nasby", )
             Re: How to improve db performance with $7K?  (Alex Turner, )
              Re: How to improve db performance with $7K?  (Alex Turner, )
               Re: How to improve db performance with $7K?  (Alex Turner, )
              Re: How to improve db performance with $7K?  (Greg Stark, )
               Re: How to improve db performance with $7K?  (Alex Turner, )
               Re: How to improve db performance with $7K?  (Tom Lane, )
                Re: How to improve db performance with $7K?  (Kevin Brown, )
                 Re: How to improve db performance with $7K?  (Greg Stark, )
                  Re: How to improve db performance with $7K?  (Kevin Brown, )
                   Re: How to improve db performance with $7K?  (Tom Lane, )
                    Re: How to improve db performance with $7K?  (Kevin Brown, )
                     Re: How to improve db performance with $7K?  (Alex Turner, )
                      Re: How to improve db performance with $7K?  (PFC, )
                     Re: How to improve db performance with $7K?  (Tom Lane, )
                      Re: How to improve db performance with $7K?  (Kevin Brown, )
                       Re: How to improve db performance with $7K?  (Tom Lane, )
                        Re: How to improve db performance with $7K?  (Kevin Brown, )
                      Re: How to improve db performance with $7K?  (Greg Stark, )
                     Re: How to improve db performance with $7K?  (Vivek Khera, )
                      Re: How to improve db performance with $7K?  ("Joshua D. Drake", )
                       Re: How to improve db performance with $7K?  (Vivek Khera, )
                      Re: How to improve db performance with $7K?  (Kevin Brown, )
                    Re: How to improve db performance with $7K?  (Matthew Nuzum, )
                     Re: How to improve db performance with $7K?  ("Jim C. Nasby", )
                   Re: How to improve db performance with $7K?  (Rosser Schwarz, )
                    Re: How to improve db performance with $7K?  (Kevin Brown, )
                   Re: How to improve db performance with $7K?  (Greg Stark, )
                   Re: How to improve db performance with $7K?  (Bruce Momjian, )
                    Re: How to improve db performance with $7K?  (Alex Turner, )
                     Re: How to improve db performance with $7K?  (Alvaro Herrera, )
                     Re: How to improve db performance with $7K?  (Bruce Momjian, )
              Re: How to improve db performance with $7K?  ("Douglas J. Trainor", )
               Re: How to improve db performance with $7K?  (, )
                Re: How to improve db performance with $7K?  (Alex Turner, )
                 Re: How to improve db performance with $7K?  (, )
            Re: How to improve db performance with $7K?  ("Douglas J. Trainor", )
            Re: How to improve db performance with $7K?  (PFC, )
             Re: How to improve db performance with $7K?  (Alan Stange, )
    Re: How to improve db performance with $7K?  (Dave Cramer, )
 Re: How to improve db performance with $7K?  ("Alexander Kirpa", )
 Re: How to improve db performance with $7K?  ("Mohan, Ross", )
 Re: How to improve db performance with $7K?  ("Matthew Nuzum", )
  Re: How to improve db performance with $7K?  (Greg Stark, )
   Re: How to improve db performance with $7K?  (PFC, )
  Re: How to improve db performance with $7K?  (Tom Lane, )
 Re: How to improve db performance with $7K?  ("Dave Held", )
 Re: How to improve db performance with $7K?  ("Mohan, Ross", )
  Re: How to improve db performance with $7K?  (Steve Poe, )
   Re: How to improve db performance with $7K?  ("Joshua D. Drake", )
   Re: How to improve db performance with $7K?  (William Yu, )
    Re: How to improve db performance with $7K?  (Greg Stark, )
     Re: How to improve db performance with $7K?  (Alex Turner, )
      Re: How to improve db performance with $7K?  (Greg Stark, )
       Re: How to improve db performance with $7K?  (Alex Turner, )
        Re: How to improve db performance with $7K?  (Jacques Caron, )
         Re: How to improve db performance with $7K?  (Alex Turner, )
          Re: How to improve db performance with $7K?  (Alex Turner, )
           Re: How to improve db performance with $7K?  (Jacques Caron, )
            Re: How to improve db performance with $7K?  (Alex Turner, )
          Re: How to improve db performance with $7K?  (Jacques Caron, )
         Re: How to improve db performance with $7K?  (Greg Stark, )
        Re: How to improve db performance with $7K?  (Alan Stange, )
        Re: How to improve db performance with $7K?  (John A Meinel, )
         Re: How to improve db performance with $7K?  (Alex Turner, )
          Re: How to improve db performance with $7K?  ("Joshua D. Drake", )
           Re: How to improve db performance with $7K?  (Alex Turner, )
        Re: How to improve db performance with $7K?  (Steve Poe, )
         Re: How to improve db performance with $7K?  (Alex Turner, )
     Re: How to improve db performance with $7K?  (Jacques Caron, )
      Re: How to improve db performance with $7K?  ("Jim C. Nasby", )
     Re: How to improve db performance with $7K?  (William Yu, )
 Re: How to improve db performance with $7K?  ("Dave Held", )
 Re: How to improve db performance with $7K?  ("Mohan, Ross", )
 Re: How to improve db performance with $7K?  ("Dave Held", )
  Re: How to improve db performance with $7K?  ("Jim C. Nasby", )
 Re: How to improve db performance with $7K?  ("Mohan, Ross", )
  Re: How to improve db performance with $7K?  ("Jim C. Nasby", )
   Re: How to improve db performance with $7K?  (Alex Turner, )
 Re: How to improve db performance with $7K?  ("Dave Held", )
  Re: How to improve db performance with $7K?  (Alex Turner, )
   Re: How to improve db performance with $7K?  (William Yu, )
 Re: How to improve db performance with $7K?  ("Mohan, Ross", )
  Re: How to improve db performance with $7K?  (Bruce Momjian, )
   Re: How to improve db performance with $7K?  (, )
    Re: How to improve db performance with $7K?  ("Jim C. Nasby", )
     What to do with 6 disks?  (Jeff Frost, )
      Re: What to do with 6 disks?  ("Jim C. Nasby", )
      Re: What to do with 6 disks?  (Josh Berkus, )
       Re: Opteron vs Xeon (Was: What to do with 6 disks?)  (Jeff Frost, )
        Re: Opteron vs Xeon (Was: What to do with 6 disks?)  ("J. Andrew Rogers", )
         Re: Opteron vs Xeon (Was: What to do with 6 disks?)  (Jeff Frost, )
          Re: Opteron vs Xeon (Was: What to do with 6 disks?)  (William Yu, )
        Re: Opteron vs Xeon (Was: What to do with 6 disks?)  (Vivek Khera, )
       Re: What to do with 6 disks?  (Vivek Khera, )
      Re: What to do with 6 disks?  (William Yu, )
 Re: How to improve db performance with $7K?  ("Mohan, Ross", )
  Re: How to improve db performance with $7K?  (Bruce Momjian, )
  Re: How to improve db performance with $7K?  (Dawid Kuroczko, )
 Re: How to improve db performance with $7K?  ("Mohan, Ross", )
 Re: How to improve db performance with $7K?  ("Mohan, Ross", )
 Re: How to improve db performance with $7K?  ("Mohan, Ross", )
 Re: How to improve db performance with $7K?  ("Dave Held", )
 Re: How to improve db performance with $7K?  ("Mohan, Ross", )

> -----Original Message-----
> From: Mohan, Ross [mailto:]
> Sent: Thursday, April 14, 2005 1:30 PM
> To: 
> Subject: Re: [PERFORM] How to improve db performance with $7K?
>
> Greg Stark wrote:
> >
> > Kevin Brown <> writes:
> >
> > > Greg Stark wrote:
> > >
> > > > I think you're being misled by analyzing the write case.
> > > >
> > > > Consider the read case. When a user process requests a block
> > > > and that read makes its way down to the driver level, the
> > > > driver can't just put it aside and wait until it's convenient.
> > > > It has to go ahead and issue the read right away.
> > >
> > > Well, strictly speaking it doesn't *have* to.  It could delay
> > > for a couple of milliseconds to see if other requests come in,
> > > and then issue the read if none do.  If there are already other
> > > requests being fulfilled, then it'll schedule the request in
> > > question just like the rest.
> >
> > But then the cure is worse than the disease. You're basically
> > describing exactly what does happen anyways, only you're
> > delaying more requests than necessary. That intervening time
> > isn't really idle, it's filled with all the requests that
> > were delayed during the previous large seek...
> > [...]
>
> [...]
> 1) some SATA drives (just type II, I think?) have a "Phase Zero"
>     implementation of Tagged Command Queueing (the special sauce
>     for SCSI).
> [...]
> Largely b/c of 2 and 3, multi-initiator SCSI RAID'ed drives
> are likely to whomp SATA II drives for a while yet (read: a
> year or two) in multiuser PostGres applications.

I would say it depends on the OS.  What Kevin is describing sounds
just like the Anticipatory I/O Scheduler in Linux 2.6:

http://www.linuxjournal.com/article/6931

For certain application contexts, it looks like a big win.  Not
entirely sure if Postgres is one of them, though.  If SCSI beats
SATA, it sounds like it will be mostly due to better seek times.

__
David B. Held
Software Engineer/Array Services Group
200 14th Ave. East,  Sartell, MN 56377
320.534.3637 320.253.7800 800.752.8129


В списке pgsql-performance по дате сообщения:

От: Alex Turner
Дата:
Сообщение: Re: Intel SRCS16 SATA raid?
От: Geoffrey
Дата:
Сообщение: Re: Intel SRCS16 SATA raid?