Facebook Goes To 64 Bit User IDs

NewsCloud writes "Facebook has announced to developers that they are moving to a 64 bit user ID in November. At 32 bits, the current ID allows nearly 4.3 billion user accounts. Yet, despite having only 47 million users today, Facebook's move to 64 bits will allow it to have more than 18 quintillion (18,446,744,074,000,000,000) user accounts. Of course, there are currently only about 6.5 billion people in the world. Is Facebook setting their sights beyond Earth or just trying to avoid what happened when Slashdot ran out of space for comment IDs last year. Perhaps they are planning to implement personas."

Comments

Re:News?

[Joe U]

Can I get a frontpage story? I used GUIDs in my database design.

Seriously, user ids?

Hi, 1985 is on the phone, they want their copy of C-Net BBS back.

Not just user IDs

[digital bath]

TFA says nothing specific to 'user ids' - it says object ids in general. I assume this includes things like comment ids, event ids, etc - which makes overflowing the 32 bit limit much more reasonable.

My guess: Security, segementation, multiple log in

[drolli]

-you can harden your security by populating the user-id space sparsely. Somebody who is guessing for an user id will have an hard time.

-It can make things easier to have your user groups organized according to geographic location, company issuing th id (e.g. local branch), etc.

-Multiple log ins. Who knows. maybe it is easier to associate internally several uids with each uid (could make things more static).

So let's say:

10 bit for segmentation
20 for checksumming
4 for multiple logins

leaves only 29 bit as payload

Or somebody was just dumb and wanted to make sure he is not fired until all applicaitons are switched