Want to upgrade 9i to 10g without downtime

Question

Hi Experts
I have a 9i database which is running our ecommerce database it is a database which is running smoothly now , however i need to update it to 10g database as all our other databases are in 10g , is there a way without downtime i can achieve this .
Ii do not have an option to shutdown the database , i have allowed at the most few seconds to achieve this . Can anyone suggest me some workable steps by way of which i can achieve this.
Probably something like a replication technique ?
Thanks Experts.

Answer 1

My "environment" uses both TNS and Java, and it takes about 5 to 30 minutes to update all database references, plus the time needed to stop all of the components, which can be anything between 5 minutes and X hours.
When reading the Oracle whitepaper called "Zero Downtime Database Upgrade Using Oracle GoldenGate", it clearly says : no downtime for the database. That part is correct. But then it says, "..very minimal time required for application switchover, typically less than one minute and in most cases, only seconds."
That's way understated, but I understand that it must fit into the "Zero Downtime" idea.
For my application, it's about between 10 minutes and X hours. It's typical for database procedures to underestimate the impact of the application. How else can one make such general statements, knowing there are hundreds and thousand sorts of applications (all Oracle), then stating - without actually knowing how they work - one can switch in 1 second. Even when dreaming, that's a bit optimistic.
But the question may to the thread opener : no database downtime, or no application downtime ?
Know that if the application has downtime, the fact that the database goes down or not (for a shorter time than the application downtime) is actually of no importance. Because end-users cannot connect anyway.