Skype Artefacts Question

I'm trying to get straight in my head the way Skype leaves behind artefacts. Specifically with respect the main.db file and the chatsync dat files.

Does anyone have a good reference that goes into this in detail (my brief Google hasn't taught me much more than I already know).

Are the chatsync dat files a form of temporary file that essentially duplicate everything that's in the main.db (albeit in less detail)?
(prior to any form of deletion/garbage collection if that occurs)

A cursory comparison shows a huge amount of overlap, in the large volumes of Skype data I have, but I'd like to understand better what gets stored where and why.

Thanks in advance for any assistance.