Re: Minimizing downtime for 9i to 10g upgrade
Date: Fri, 12 Sep 2008 18:44:37 -0700
> DA Morgan wrote:
>> Chuck wrote: >>> I need to upgrade a 9i database to 10g but the business unit cannot >>> tolerate any downtime. I've advised them the cleanest way is to upgrade >>> the db in place which takes about 90 minutes. They are uncomfortable >>> with that much down time. An exp/imp to a new 10g database would take >>> even longer. >> Why? you can do TB systems in seconds. >> >> First set up your 10g database. >> Then copy over all of the rows except for the last 24 hours. >> >> Then copy over all of the information not previously copied except for >> the last hour. >> >> Repeat for everything except the previous 2-5 minutes. >> >> Then switch them over. This is the few seconds. >> >> Then bring in that last five minutes worth of transactions which likely >> will never be missed in the minute or two it will take to capture them. >> >> This technique is aided by the use of partitioning and I highly >> recommend several practice runs to perfect your technique.
> I think you must mean "terabyte" by tb. At first I thought you were
> talking about some software product by a company called "tb systems" :-).
> How do you automate the copy of rows to know which ones were updated in
> previous hour, 2-5 minutes, etc.? Are you suggesting converting every
> table in the database to a materialized view, with an mview log, and
> refreshing periodically? Is this supported across different major releases?
> I would think whatever you're talking about needs to be SQL based as I
> dont believe log shipping is supported between major releases.
> Can you please clarify? Thanks.
One way is to add a column to each table. Not pretty. Another is the temporary use partitioning since the database will be blown away in a week or less. A third way is with DBMS_WM (workspace management). Give me a minute or two and I can likely come up with a few more.
Again it all depends on what is going on, the size, dependencies, etc. None of which were stated by the OP.
-- Daniel A. Morgan Oracle Ace Director & Instructor University of Washington damorgan_at_x.washington.edu (replace x with u to respond) Puget Sound Oracle Users Group www.psoug.orgReceived on Fri Sep 12 2008 - 20:44:37 CDT