Many people in the Enterprise Vault administration world have heard of an MDC file. Not everyone knows what it is though.. or what it looks like. Below I’ll explain and show you.
The MDC file is the Metadata Cache file. It contains mail messages, these resemble your archived items, but they’re not ‘quite’ the same. Essentially the folder structure will follow the structure of your archive, and the mails are actually stubs, containing only some of the message metadata, and a short snippet of the message body (no attachments etc). Another way to look at it is that is your Virtual Vault. Obviously the Enterprise Vault Outlook Add-in has lots of code in it which manipulates these items, and presents them to you in such a way that they can seamlessly be your ‘full’ archived items, metadata, attachments and all.
The screenshot below shows you an example of the file:
The other important thing to note is that you get the full MDC file always, whereas the content files (the .DB files in the above screenshot – which I’ll cover in another blog post) you may only get ‘some’ of those depending on the amount of space you want Vault Cache to consume. As I said though, you will always get the full MDC file.
If you take a copy of that MDC file with Outlook closed, rename it to PST and attach it to your Outlook profile you will see that it contains the structure of your archive, and the stub information that I already mentioned:
Compare that with the same ‘view’ when the Outlook Addin is involved and it is truly your Virtual Vault: