KMail2 backup: can ignore the akonadi stuff?

[Anton]

Hi,

I want to switch from Kubuntu 11.10 to 12.04.

In earlier time backup of my mails was easy: 
  tar the .kde folder and you're done.

Now we have akonadi (and nepomuk) & a mysql server running
in my opinion:
1. overkill: a simple file based sqlite would have beet simpler
2. security issue due to indexing: 
    Immagine I have a *temporarily* mail with some 
    "private" stuff like credit card number / password.
    If I delete (or wipe) my email: how can I get sure
    that this data is *not* surviving as ghost in some index file.
    The same issue nepomuk: I do not want a system using constantly
    cpu/memory/disk indexing stuff which I want to search only 
    from time to time.
    I would prefer to search explicitly when I need to, but nepomuk/akonady
    (or only akonady do not remember) need to run or Kontakt & friends do
    not work anymore.

Ok, after my remarky (yes I am whining a little bit) I have one question:

Is it enough to back up the .kde folder *ignoring* the akonadi 
mysql database?

Or will I have some mails lost?

Thanks

  Anton