opening an iphoto 09 library on iphoto 11

It needs to upgrade the library, but will be fine. If you're worried, make a copy of it, and just FYI you won't be able to open it with previous versions of iPhoto after the conversion.

 

If you really want to "start fresh" you could open the library with the Finder and reimport all the photos into a new, iPhoto 11 library.

But why? You'd lose all the info you added, crops, faces, keywords, etc.

I would imagine Migration Ass't will automatically move it for you and iPhoto will upgrade the library in the process or when you first open iPhoto.

And check out iPhoto Library Manager if you want some more control over your libraries, especially if they are growing too large for easy portability.

 

I've just done exactly this with my new MBP.

The first time you open iPhoto 11, it will offer to import older libraries, and convert them to the latest format.

I'm not sure what the technical differences are, but my photos looked exactly the same!