Order and noorder options are relevant only for the OPS/RAC configurations
because that is the only way that the sequence numbers may be returned out
of
order. If the sequence is not cached, then you'll suffer a logical read and
a physical write each time you query the sequence. What will be a
performance
impact? It depends primarily on you disk configuration, whether your
database
is a file system one or is it on raw devices and how much cache are you
having
on your disk controllers.
> -----Original Message-----
> From: Thomas Day [mailto:tday6_at_csc.com]
> Sent: Wednesday, October 09, 2002 11:54 AM
> To: Multiple recipients of list ORACLE-L
> Subject: Re: sequence numbers
>
>
>
> If the sequence is not cached then Oracle has to generate a
> new sequence
> number for every record inserted (CPU cycles). NOORDER is
> the default so
> that won't slow you up. If you're doing bulk loads why not cache the
> sequence numbers? Is it important that there be no gaps? Even with
> NOCACHE you can get gaps. If a sequence number is generated
> but the row
> (insert or create) is not COMMITed the sequence number is not
> rolled back.
>
> Unless there are fewer than 100 rows to be inserted I'd go with some
> caching.
>
>
>
>
>
> April Wells
>
> <awells To: Multiple
> recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
> @csedge.com> cc:
>
> Sent by: root Subject:
> sequence numbers
>
>
>
>
> 10/09/2002
>
> 10:54 AM
>
> Please
>
> respond to
>
> ORACLE-L
>
>
>
>
>
>
>
>
>
>
> I have been given create scripts for sequences to be used in
> tables that
> will be loaded via bulk loads. How huge is the potential
> performance hit
> if I take out the cache 20?
>
>
> April Wells
> Oracle DBA
> There is neither good nor bad, but thinking makes it so. -Shakespeare
>
>
> << Attachment Removed : InterScan_Disclaimer.txt >>
>
>
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: Thomas Day
> INET: tday6_at_csc.com
>
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Received on Wed Oct 09 2002 - 11:33:50 CDT
