Re: Using oracle dump (quickly!)

Hello Hans,

  You mixed up two things.

  100M - is a recommendation for imp buffer size.

  4M+ is a recommendation for LOG_BUFFER.

Regards,

  Ron
  DBA Infopower
  http://www.dbainfopower.com
  Standard disclaimer:
http://www.dbainfopower.com/dbaip_advice_disclaimer.html

"Hans Forbrich" <hforbric_at_yahoo.net> wrote in message news:yu5%b.37475$n17.4264_at_clgrps13...
> Ron wrote:
> >>Usually a buffer parameter of 8M is more than sufficient
> >
> >
> > I use 100M+ as well - always works. Hope user can decide if bigger is
> > better
> >
> >
> >>Setting LOG_BUFFER too anything
> >>higher than 1M is useless, as the buffer is written to disk when 1M is
> >>dirty.
> >
> >
> > As far as I remember, 1M is upper bound for _log_io_size under Oracle8
> > (according to Steve Adams as well). _log_io_size is 1/3 of the log
buffer
> > expressed in log blocks. So setting to LOG_BUFFER 4M during the big
import
> > would not hurt
> >
> >
> >>3 Nologging doesn't have any impact on import at all.
> >>It is only applicable using direct path operations, i.e. in inserts
> >>using the /*+ append */ and using sqlloader in direct mode. Import
> >>doesn't work in direct mode.
> >>
> >
> >
>
> (Still top posting, I see. Bad habits die hard, I guess.)
>
> You might want to look at
>

http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96533/memory.htm#29731
>
> where you'll find the following statement
>
> "
> A reasonable first estimate for such systems is to make the log buffer 1
> MB. On most systems, sizing the log buffer larger than 1m does not
> provide any performance benefit. Increasing the log buffer size does not
> have any negative implications on performance or recoverability. It
> merely uses extra memory.
> "
>
> I wouldn't be surprised to see some benefit from 4M or 8M in certain
> circumstances, but the above statement indicates that 100M is likely a
> bit of useless overkill.
>
> (Apparently your organization has money to waste - at least in extra
> memory. Since it's not being used effectively anyway, pass some this
> way <g>)
>
> /Hans
Received on Wed Feb 25 2004 - 12:27:12 CST