In the August CTP Microsoft introduced Data-Tier Applications and several new features were introduced in the Nov 2009 CTP. Registering; Viewing & comparing and upgrading Data-Tier applications were added.
A Data Application Component is an entity that integrates all data tier related objects used in authoring, deploying and managing into a single unit instead of working with them separately. Programmatically DACs belong to classes that are found in The Microsoft.SqlServer.Management.Dac namespace. DACs are stored in a DacStore and managed centrally. DACs can be authored and built using SQL Server Data-Tier Application templates in VS2010 (now in Beta 2) or using SQL Server Management Studio. This article describes creating DAC using SQL Server 2008 R2 Nov-CTP(R2 server in this article), a new feature in this version.
The following two articles treat DATPACs from two different angles. The first part is what you or a DBA can do in SQL Server Management Studio and in the second what a developer can do in Visual Studio.
Using SQL Server Management Studio
In the first part of this series [http://www.packtpub.com/article/working-with-data-application-components-sql-server-2008-r2] the author shows shows how you may extract a Data Application Component from a SQL Server 2008 and then deploy the component to an SQL Server 2008 R2 Server. The process is Wizard driven and very easy to understand. DAC files in the field of DATA are like *.msi files for applications. Just as you would install an application from an MSI file, you would install a database package with the DAC file with the extension DACPAC. You may even email a database. The cited article shows how all this is done.
Using Visual Studio
In the second part of this series[http://www.sswug.org/articles/viewarticle.aspx?id=49844] the author shows how you may create a DATPAC from scratch in your Visual Studio IDE. You will start creating a DATPAC which has database with a table and a view based on the table even when not connected to a server. You will then manually deploy the DATPAC to the server after connecting to it and complete the deployment.