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From Mike Matrigali <mikem_...@sbcglobal.net>
Subject Re: Soft upgrade
Date Thu, 22 Mar 2007 16:52:56 GMT
Assume you have a 10.2 database/application.  If you choose to run
10.3 against this database and not do a hard upgrade, you are in
"soft upgrade".  You should be able to do every operation in this
mode that you were able to do against 10.2 (ie. including ddl and dml).
You may be prevented from doing things that are new to 10.3 as they
may write out structures to disk which cannot be read by 10.2 software.

The thing to keep in mind is that under soft upgrade you should always
be able to go back to using 10.2 software and have no problems accessing
the data in the db.  This is the basic difference between hard and soft
upgrade.  If a hard upgrade is performed one cannot use 10.2 software
on the 10.3 database.

I believe that we don't prevent all 10.3 features
in this mode, so the application may change to use the 10.3 features and
then fail when it moves back to 10.2.

Mamta Satoor wrote:
> Hi,
>  
> I have a generic question about soft upgrade. Are users allowed to 
> perform DDL/DML while the database is in the soft upgrade mode? Or are 
> they only allowed to query the database? If user is allowed to do DDL 
> and DML, then Derby must have special code for soft upgrade which 
> prevents operations which can result in change in data structures which 
> are not compatible with the actual database version.
>  
> Mamta


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