![]() ![]() There’s no single bottleneck that could one day be a problem for scaling or performance. ![]() Multiple entities can generate IDs independently, but still store them to a shared data store without clobbering each other. The fact that they’re random means that they don’t rely on a single sequence to be generated. UUIDs as primary key aren’t a slam drunk, but do have some advantages: When we’re talking about UUIDs, we’re often talking about V4 UUIDs, which is a fancy way of saying that the entire UUID byte sequence is generated randomly, as opposed to using an algorithm based on clock sequence or anything else. It’s worth remembering that although we’re used to seeing them as strings, when they’re being stored (properly) in a database, to the machine they’re not all that different from any other sequence of bits – they’re twice the length as a standard 64-bit integer, but stored and compared similarly. UUIDs are 128-bit sequences that are canonically represented in hex-encoded string form like 63bb4648-0b42-497f-9ad8-571cd60ee4f3. Id uuid DEFAULT gen_random_uuid() PRIMARY KEY, UUIDs, V4, ups and downs CREATE TABLE has_uuid_pkey ( There are small advantages over the other on each side, and some pitfalls that should clearly be avoided, but when used mindfully, both integers and UUIDs make quite workable solutions, with (in my opinion) appropriately levered UUIDs edging out a little ahead. Over the years since the guide was written I’d starting leaning further back in the direction of integers being the right answer, but now that I’ve read into the subject more deeply, I’m less convinced that there’s a right answer at all. Years ago when we published the Heroku HTTP API design guide, we suggested using UUIDs to identify all resources, but without any real rationale for why, and quite fairly, someone had recently opened a GitHub issue on the repository to challenge the point. Its publication was quite timely for me, as I’d been considering it very recently in the context of our own application, which I joined to find was using UUIDs, contrary to what I probably would have chosen had I been there at the beginning. Although freshly written, it’s only the latest talking point in a long-standing discussion amongst DBAs and database nerds that’s been ongoing for years – should you use integers (AKA serials, AKA sequences) or UUIDs as primary keys? bigserial vs IDENTITY as primary keys in a Postgres database. Sequences - an alternative to auto_increment available from MariaDB 10.Last month, Cybertec put together an excellent piece on the use of UUIDs vs.UUID() Return full (128 bit) Universally Unique Identifier.Statements using the UUID_SHORT() function are not safe for statement-based replication. The UUID_SHORT() return value is constructed this way: (server_id & 255) << 56 ![]() Million times per second between mysqld restarts You do not invoke UUID_SHORT() on average more than 16.You don't set back your system time for your server between mysqld restarts.The server_id of the current host is unique among your set of master and.The value of UUID_SHORT() is guaranteed to be unique if the Than a string-form 128-bit identifier as returned by the UUID() function). Returns a "short" universally unique identifier as a 64-bit unsigned integer (rather ![]()
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