• From: "Andrzej Jan Taramina" <andrzej@c...>
• To: "Costello, Roger L." <costello@m...>
• Date: Tue, 08 Jan 2008 13:41:12 -0500

Roger said:

> I would like to propose the following data versioning principle: 
> 
> PRINCIPLE OF WEB SERVICE DATA VERSIONING 
> Don't base your web service data versioning strategy on a data validation
> strategy. Rather, base it on business needs. 
> 
> DISCUSSION 
> Don't base your versioning strategy on an XML validation strategy, such as
> maintaining backward compatible XML Schemas. It's the data that the web
> service makes available to its consumers that matters, not how the schema is
> designed. Your web service may have a business need to create a new version in
> which new elements are added, old elements are deleted, and existing elements
> are rearranged ...many of these changes would not be possible if your
> versioning strategy were constrained by some XML validation strategy such as
> trying to maintain backward compatible XML Schemas. The only thing that
> matters is the XML instance documents that the web service makes available to
> its consumers. The design of the XML Schema that the instance documents
> conform to is irrelevant. 
> 
> QUESTIONS 
> 
> 1. Do you agree with this principle? 
> 2. If so, can you provide a name for the principle? (e.g., the _______ 
> principle) 

I do agree.

Call it the Costello Principle! ;-)


Andrzej Jan Taramina
Chaeron Corporation: Enterprise System Solutions
http://www.chaeron.com

• References:
  • RE: RE: Caution using XML Schema backward- or forward-compatibility as a versioning strategy for data exchange
    • From: "Costello, Roger L." <costello@m...>