Re: MaterializeRe: Snapshot Logs Explanation Needed

From: A. Bardeen <abardeen1_at_yahoo.com>
Date: Sat, 02 Jun 2001 06:36:49 -0700
Message-ID: <F001.003192E5.20010602061024@fatcity.com>

Dave,

/* SOAPBOX ON */ I'm well aware that hacking the data dictionary is possible, but you'll never see me advocating that on the list. I believe hacking should be done only as a last resort to save a db or avoid rebuilding it and even then should be done only under the guidance of Oracle Support. In many cases even they won't let you make the changes, but will require dial-in access so they can make the changes to ensure that they're done properly.

Since there are virtually no PK/FK relationships defined in the data dictionary it's far too easy to miss one of the relationships and end up with a corrupted dictionary. Said corruption may not manifest itself until days, weeks, or months later, at which point you'll have a bigger and messier problem than the original one. So even if you practice this on a test db and it seems to work OK, it might just be that you haven't performed the operations that would reveal the corruption.

Definitely not something I want to attempt via email. IMHO the disclaimers "backup first" and "use at your own risk" are insufficient.

/* SOAPBOX OFF */

• Anita
  • Dave Morgan <dave.morgan_at_cybersurf.net> wrote:
    > Hi Anita,
    > I'm not sure if you are the original poster but
    > ....
    >
    > There is a way to force a view into fast refresh
    > mode
    > after you have restructured the snapshot logs
    >
    > WARNING: This is unsupported by Oracle and involves
    > messing
    > with the data dictionary.
    >
    > I once had to create a 4GB snapshot over an ISDN
    > line
    > This was done by creating the snapshot locally,
    > exporting,
    > ftp, import and then:
    >
    > In DBA_SNAPSHOTS (I believe) I compared the entry
    > in the local
    > database to the remote. One field was different in
    > my case. A simple
    > update to the data dictionary enabled the FAST
    > REFRESH to take place.
    >
    > THIS IS DANGEROUS STUFF :)
    >
    > Dave
    >
    > --
    > Dave Morgan
    > DBA, Cybersurf
    > Office: 403 777 2000 ext 284
    > --
    > Please see the official ORACLE-L FAQ:
    > http://www.orafaq.com
    > --
    > Author: Dave Morgan
    > INET: dave.morgan_at_cybersurf.net
    >
    > Fat City Network Services -- (858) 538-5051 FAX:
    > (858) 538-5051
    > San Diego, California -- Public Internet
    > access / Mailing Lists
    >

    ---

    
    > 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).
    

    ---

Do You Yahoo!?
Get personalized email addresses from Yahoo! Mail - only $35 a year! http://personal.mail.yahoo.com/

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: A. Bardeen
  INET: abardeen1_at_yahoo.com

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
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 Sat Jun 02 2001 - 08:36:49 CDT