Optimizing PostgreSQL performance when using UUIDs as primary keys

Question

I'm new to databases and have been considering using a UUID as the primary key in my project, but I read some things which made me interested to learn more about the performance.

Currently, I am using the uuid data type and the default value is set to gen_random_uuid().

First of all, I was wondering: would UUIDs be less performant as a primary key?

If so...

• Are there any tips to optimize it, e.g. would it help if the PK was sequential, but another field contained a UUID, specifically for public exposure?
• Are there any similar alternatives which may be more performant?

(I'm not working with data of any considerable scale just yet; it's more of a theoretical question.)

Answer 1

UUIDs are slower than keys generated by a sequence. You'll just have to accept that, there is no way around it. For that reason you use UUIDs only if you have a compelling reason, like the keys are generated outside the database or need to be unique across several database.

There is some deeper discussion of this in my article.