Alfresco WCM and 'Database' apps

[marfarma]

I'm just beginning to wrap my head around web development in Alfresco.  I'm continuing to review the existing documentation I have at the moment, including the Packt Alfresco Developers Guide.  But here's a question I haven't seen being discussed anywhere in the documents I have.  I'm trying to compare Alfresco WCM to typical database backed web app development.  Given that:

1) data that might otherwise use SQL server for persistence can be modeled as custom content type(s) in Alfresco. 
2) data can be maintained in Alfresco as XML instances of these custom content types. 
3) Alfresco API calls can be used to create static or dynamic sites which include the custom content data 
4) WCM can be used to develop and deploy those websites – although they can also be developed using the API and other tools.

We can certainly replace traditional SQL backed web applications with Alfresco XSD/XML backed applications.  (Certainly I'm not suggesting anyone should implement Twitter part 2 against Alfresco!)

I wonder, is there's any consensus on where the lines fall, how to decide for a particular project, and how to use both database and document data store together in the development of a website?  Any existing discussion you can point me at?

[mrogers]

There's discussions on these forums.

A rule of thumb could be that if you are managing "content" you use a system like Alfresco.     If its a highly relational app that then use a RDBMS. 

Some examples.   If its a "newspaper publishing" type app, approving and publishing "articles".  Or a document library.   That's suited to a system like Alfresco.         

If its your accounting system with lots of complex tax rules etc then that needs to be in the RDBMS. 

But it then becomes blurred.   Say that the accounting system contains lots of scanned invoices that need to be transformed, approved and archived.   Then you could end up using both Alfresco AND an RDBMS together.    Practically this will just mean putting appropriate keys into each application.    And thinking through the rules for deleting data.

The WCM world is similar If you are presenting a web interface to a relational database then Alfresco may not suit.   Equally if your web site consists of bits of content, some images, some text, some code, some PDFs to download, that's where alfresco comes in.