Using UUID as pkey in sqlite db

I am not sure what is the real question here, but let's assume it was "what are the advantages of using such identifiers in SQLite instead of say a normal integer...?"

Well, for example this comes handy if you need to combine records from two or more sources into a single centralized database.

 

The UUID is unique for each device. Each device has one and only one and no other device has the same one.

I don't see why you would use it for a sqlite db on the device.

It is used by some to identify data sent from users to a server-based db. Some security professionals consider using the UUID in this manner to be an invasion of privacy. Many analytics and ad-servers etc do send the UUID off the device and use it as a unique identifier, behind the back of the user.

 

UUID is a Universally Unique IDentifier. It's a generated value, and changes each time it's generated. It has a statistically low probability of being generated by another device, or at another time (practically unique).

UDID is the device's Unique Device IDentifier. It's a stored immutable value, that is always the same on each device, but different across devices (guaranteed unique). It's effectively the device's unique serial number.

 

There is no benefit in using a UUID or GUID as a key compared to an autoincrement integer.

 

Now I'm lost - are we talking about device id here or about the value returned by CFUUIDCreate() function? At first I was sure it's the later.

Code:

   CFUUIDRef    newUniqueID    = CFUUIDCreate (kCFAllocatorDefault);
   CFStringRef  newUniqueIDStr = CFUUIDCreateString (kCFAllocatorDefault, newUniqueID);

 

There is if you want the keys to be unique across devices, although I'm not sure if it's technically more efficient to use a regular integer as the primary key and have the UUID be another column that you only use when you need to find/compare things across devices.

 

This is untrue. The main point of UUIDs is the lack of a need to consult a central authority in order to generate an identifier. Each party can just make up their own whenever they need to. Sequential values, on the other hand, have to be coordinated. Now whether or not this capability is a benefit to a given system system depends on the needs of that system.