Database field usage description

[cbastos]

I´m trying to migrate from a proprietary system to Coppermine.
In order to decrease migration times, I´d like to know which tables and fields are modified in these four operations:

1-Adding a user
2-Adding a post
3-Adding a comment
4-Adding a image

It would be very helpfull if someone already studied these operations.

[Nibbler]

1. New row in users table
2. No such thing
3. New entry in comments table
4. New entry in pictures table