A.1. To Convert or To Enable
You have several things to consider when deciding whether to convert an application to the new Access 2007 ACCDB format. The primary reason to convert is to take advantage of the powerful new features that require the ACCDB file format, such as the ability to work with complex data, the ease of collecting data from e-mail forms, and better integration with the web and SharePoint Services. To store complex data, Access 2007 includes a new system table, called MSsysComplexColumns, and a series of built-in table schema to automatically manage look-ups that would otherwise be many-to-many relationships. However, the ACCDB format cannot be linked to by an .mdb file, does not support replication (but offers an alternative), and does not work with group-level security (as implemented using the .mdw file. Access 2007 .mdb files will work with these features. So in a mixed version environment, keep in mind that although an .accdb file can link to or import from an .mdb file, the opposite is not true.
A.1.1. Speaking the Same Language
Before we delve into the decision criteria, let's be sure that we are speaking the same language. Words such as "upgrade," "migrate," "convert," and "enable" are sometimes used interchangeably. To make the discussion easier, here's how those words should be interpreted for the purposes of this appendix:
Upgrade: You have Office and Access 2007 instead of some prior version. And, with purchases, "upgrade" is often associated with ...