Oracle-L: Re: sequence numbers

From: Thomas Day <tday6_at_csc.com>
Date: Wed, 09 Oct 2002 07:53:52 -0800
Message-ID: <F001.004E46E9.20021009075352@fatcity.com>

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

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: ListGuru_at_fatcity.com (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).

Received on Wed Oct 09 2002 - 10:53:52 CDT