Re: Daylight savings time, shutting down oracle

In article <972653992.24870.0.nnrp-09.9e984b29_at_news.demon.co.uk>,   "Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote:
> There is the possibility of needing to recover to a
> point in time. If the clock goes back at 2.00 am
> you get two shots at 1:30 am that day.
>
> So if you try to recover to '1:30 am' Oracle
> will stop at the first 1:30. (Which means you
> have to raid the log file to find out the last SCN
> that appeared before 1:30, I suppose, but how
> many people have got the book that tells you
> how to do that ?)
>
> It is a valid cause for concern, but one which
> could, perhaps, be circumvented.
>
> --
>
> Jonathan Lewis
> Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk
>
> Practical Oracle 8i: Building Efficient Databases
> Publishers: Addison Wesley Longman
> Book bound date now 1st Dec 2000
>
> Brian Peasland wrote in message

 <39F981B9.18B39C5E_at_edcmail.cr.usgs.gov>...
> >krp,
> >
> >On other database systems that I worked on, each transaction is
> >timestamped. So on those systems, the database had to be down for an
> >hour in the Fall's time change. Oracle uses a sequence number (SCN)
 to
> >stamp each transaction. So for transaction reasons, you do not need
 to
> >bring down an Oracle db for the upcoming time change.
> >
> >But there might be application issues. The application might store
 the
> >time of a transaction in a table somewhere. There could be ill
> >consequences if the time is changed back in those applications.
> >
> >HTH,
> >Brian
> >
> >
> >kpacek_at_excite.com wrote:
> >>
> >> I'm sysadmin for a few boxes running oracle. Some are Solaris 8,
> >> oracle 8.0.1 others hp-ux 10.2, oracle 7.3.4 (I think). My DBA's
 are
> >> insisting that the db's be shut down between 1:30 -3:30 am Sun,
 during
> >> daylight savings time.
> >>
> >> Is there any point to this? Can anyone describe how oracle handles
> >> this or point me to a resource so I can bring the information to
 them
> >> to show that there is no reason for this? It seems to me, the box
> >> really runs GMT behind the scenes, where there is no such thing as
> >> daylight savings time.
> >>
> >> Thanks
> >> krp
> >>
> >> Sent via Deja.com http://www.deja.com/
> >> Before you buy.
> >
> >--
> >========================================
> >Brian Peasland
> >Raytheons Systems at
> > USGS EROS Data Center
> >These opinions are my own and do not
> >necessarily reflect the opinions of my
> >company!
> >========================================
>
>

(Which means you have to raid the log file to find out the last SCN  that appeared before 1:30, I suppose, but how many people have got  the book that tells you how to do that ?)

Should one be running 8i one has access to the DBMS_LOGMNR package which can provide the SCN information one would need to perform an SCNbased  recovery.

--
David Fitzjarrell
Oracle Certified DBA


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