.ABCDDB File Extension
File TypeApple Address Book Contact List
What is an ABCDDB file?
File created by Address Book, a contact organization application; contains a contact list, in SQLite database format, of all the contacts stored within the Address Book application; regenerated when the Address Book application is opened; not meant to be manually opened.
The ABCDDB file can be found in the following directory:
UserHome(Home Icon) > Library > Application Support > AddressBook
NOTE: OS X Mountain Lion replaced the Address Book application with the Contacts application.
AddressBook-v22.abcddb - If your Address Book contacts aren't displaying correctly, quit the application, move this file from the "AddressBook" folder to your desktop, and start up the Address Book application again.