What concerns are there respect to use a short-UUID-like type as primary key?

Question

I'm thinking to use (on PostgreSQL v13) an UUID type (with uuid_generate_v4()) for my tables with high traffic, and the others with a Text type (as primary key) by using an auto-generated similar to crypt(now()::text, gen_salt('des')) (short UUID?).

What concerns are there respect to use this short-UUID-like type? Can it be considered a good practice? If not, what suggestions do you propose?

Let's suppose to have a table with various foreign keys (FK), every FK is an UUID type, then when we open that table we'll see a long sheet stretching horizontally, or when we make a API call returning a list of objects with their IDs, well it is not cool.

I was checking some API calls available on Net, and they use some short-UUID-like type with a fixed length of 10 chars, so I was thinking, how do they get that result without getting any conflicts? What about its performance? etc.

Answer 1

Whatever you do, don't use a text type to store fixed-length binary data. For example, UUIDs stored as text take 33 bytes, while the UUID type takes only 16 bytes. Your "short-UUID-like type" is 13 characters, taking 14 bytes when stored as text. For a saving of only 2 byes and a risk of collisions, I wouldn't use it.