certutil options ?

Hello

I have a following requirement:

a) create a new NSS SQLite DB 
b) copy existing data from our prior SQLite DB into newer DB.

On perusing, I came across below command:

 The --merge command only requires information about the
   location of the original database; since it doesn't change the
   format of the database, it can write over information without
   performing interim step.
certutil --merge -d [sql:]directory [-P dbprefix] --source-dir directory
 --source-prefix dbprefix [-@ password-file]

   For example:
$ certutil --merge -d sql:/home/my/sharednssdb --source-dir /opt/my-app/
alias/ --source-prefix serverapp-



Does this create the new SQLite DB ? 
Is -d [sql:]directory option creating new SQLite DB or is that original DB ? 
Not quite sure what --source-dir option is or for that matter --source-prefix?


Any help greatly appreciated.

Thanks..