Performance is really bad, if you save them as strings and use those strings as keys. If you take them as 128 bit integers, it’s kind of fine. Often 32 bit int

Performance is really bad, if you save them as strings and use those strings as keys. If you take them as 128 bit integers, it’s kind of fine. Often 32 bit integers are anyway not long enough as a primary key, so you need at least 64 bit keys. UUID is just double the size then.