I’m writing this post as lot of people seem to have some misunderstanding how the BCS Client Object Model works. BCS client object model is different from SharePoint Client Object Model. It comes as a part of Office Professional Pro SKU and contains classes which help to consume/update data from External System using Office Clients. SharePoint Workspace 2010 and Outlook 2010 uses this OM to take External list offline and work on the data on client.

 

These are important things to understand:

-          It works directly against the external system. Therefore any calls you make against the external system gets/updates items from the External System bypassing SharePoint. You can have a solution with no SharePoint in middle!

-          The Client OM has capabilities to cache data, therefore providing offline experience and performance enhancements. The data is maintained in a SQL CE database which is per-user and maintained in the profile created for logged on user in Windows. Client OM let you issue update calls in offline mode. It queue’s these calls and when system comes online, execute them against external system.

-          First level of security is provided by the fact that the SQL CE DB is tied to logged on user. An organization can implement better and stronger security on client using the BitLocker encryption which will encrypt the drive and SQL CE cache also.

-          There are different schemes available for authenticating the user who is directly against the external system. It includes Windows authentication and Single Sign On Provider on client for Windows Authentication.

-          SQL CE cache is shared. What this means is once the data is synchronized to client, it can be consumed from any Office application. The data is available via code to all the Office apps.

 

Hope this helps you get an understanding of the Client OM and make some compelling apps using this new capability.

 

Refer to following msdn entry for more information: http://msdn.microsoft.com/en-us/library/ee559310(v=office.14).aspx