RE: reset the SCN for the database

Humm, there is 60 seconds in a minute, 3600 in an hour, 86400 in a day,
31,536,000 in a year and 15,768,000,000 in 500 years.  So at 16K commits
per second that makes the largest SCN = 252,288,000,000,000 which is one
heck of a lot of transactions.
 

Dick Goulet 
Senior Oracle DBA 
PAREXEL International 

 

________________________________

From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of K Gopalakrishnan
Sent: Wednesday, July 15, 2009 2:22 PM
To: TESTAJ3@xxxxxxxxxxxxxx
Cc: hrishys@xxxxxxxxxxx; oracle-l@xxxxxxxxxxxxx;
oracle-l-bounce@xxxxxxxxxxxxx
Subject: Re: reset the SCN for the database


Joe, 
 
Going by the standard answer, it will take around 500 yeras for you to
run out of SCN with 16K commits/sec.  So there is no way you will run of
SCNs in (y)our life. Also the SCN structure has an internal limitation
of increment values. It can not be incremented to arbirarily high
values. So you can not use the ADJUST_SCN or _minimum_giga_scn to reach
the limit :)
 
So technically speaking the first error you may get with currnet
versions of will be ORA-1513, but you will get umpteenl ORA-1558s as all
the rollback segments would have dead by that time.

Best Regards,
K Gopalakrishnan

Oracle Database 10g Real Application Clusters Handbook
http://www.amazon.com/gp/product/007146509X/

Oracle Wait Interface: A Practical Guide to Performance Diagnostics &
Tuning
http://www.amazon.com/exec/obidos/tg/detail/-/007222729X/



On Wed, Jul 15, 2009 at 12:13 PM, <TESTAJ3@xxxxxxxxxxxxxx> wrote:



        A discussion many years ago asked "what happens if you run out
of SCNs?"  Curious minds still want to know or has this already been
answered. 
        
        joe 
        
        _______________________________________
        Joe Testa, Oracle Certified Professional 
        (Work) 614-677-1668
        (Cell) 614-312-6715
        
        Interested in helping out your marriage?
        Ask me about "Weekend to Remember"
        Dec 11-13, 2009 here in Columbus.
        
        
        
        
From:   K Gopalakrishnan <kaygopal@xxxxxxxxx> 
To:     hrishys@xxxxxxxxxxx 
Cc:     oracle-l@xxxxxxxxxxxxx 
Date:   07/15/2009 01:08 PM 
Subject:        Re: reset the SCN for the database 
Sent by:        oracle-l-bounce@xxxxxxxxxxxxx   

________________________________




        Hrishy, 
          
        Resetlogs does not reset the SCN. It just resets the LSN (Log
Sequence Number), thats why it is RESET-LOGS. You can advance SCN by
ADJUST_SCN event (which goes only forward btw). You may consider
FLASHBACKS to go back to the past. 
          
        -Gopal
        
        On Wed, Jul 15, 2009 at 4:44 AM, hrishy <hrishys@xxxxxxxxxxx
<mailto:hrishys@xxxxxxxxxxx> > wrote: 
Hi 
  
One of my environment makes use of streams and if i do a incomplete
recovery using resetlogs the SCN would be reset.How do change the SCN to
make it go back to what it was earlier. 
  
  
regards 
Hrishy

Other related posts: