Re: Managing structural DB changes

Hi Markus,

have a look at http://www.stepwise.com/Articles/2005/DBChanges/ 
index.html for a database updater. For each db version you use with  
your different app versions you have an incremental change class. So  
you have classes that update V2->V2.1, V2.1->V2.2, ...
When your app launches it will look in a special table that it  
creates in your database on which version it is and updates it to the  
last version it has update classes for.

jw

Am 14.11.2007 um 11:43 schrieb Markus Ruggiero:

> This may be OT in direct relation to WO but certainly not in  
> relation to deployment of large scale db apps.
>
> I am sure some (all?) of you have or will have at one point in time  
> the following problem:
>
> You deploy your version 1.0 application at a customer site with a  
> certain database structure. Now you continue developing your app  
> and soon the greatest new version 2.0 will be available. However  
> the database structure has changed and you face the problem that  
> you have to upgrade the database at the customers site. A simple  
> export / drop tables / create tables / import is not doable because  
> you may have to split or join tables, move attributes to different  
> tables, and make incompatible changes to data types.
>
> How do you manage such a scenario? In my case the application  
> manages third party devices (phones). Now every couple of months  
> the vendors update those devices or throw completely new ones with  
> new capabilities on the market. Our customers expect our  
> application to support those new phones and the new or changed  
> features. As we are managing different phones from different  
> vendors in a unified way we have to update our datamodel all the  
> time. As this is an app for the corporate high end market we have  
> customers with different releases. Sometimes we have to upgrade a  
> customer from V2 to V3, sometimes it is V2.1 to V2.2 or V2.8 to  
> V3.4. This means that upgrades are incremental but the necessary  
> increments may change from installation to installation
>
> Any and all inputs very welcome
> Thanks and have a nice day
>
> ---markus---
>
> Markus Ruggiero
> rucotec consulting and technologies    email      
> mailto:[email protected]
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