UUID v1 is generated by using a combination the host computers MAC address and the current date and time. We’ll talk about v5 later V1 : Uniqueness UUIDs are just 128 bit pieces of data, that is displayed as (128/4) = 32 hexadecimal digits, like this : ba6eb330-4f7f-11eb-a2fb-67c34e9ac07cĪt first glance UUID v1 and v4 look the same, but try regenerating them and the difference will be more apparent. This is a tradeoff between uniqueness and randomness, and something that the different UUID versions solve in different ways. How do you ensure that there is just one copy of the identifier you made, and no more? And even then, how do you make sure that there is no correlation between any two identifiers? However, ensuring uniqueness is a challenge in itself. UUIDs address the problem of generating a unique ID, either randomly, or using some data as a seed. The universally unique identifier, or UUID, was designed to provide a consistent format for any unique ID we use for our data. Having a unique identifier is an important requirement in many applications today. This post will describe and illustrate the different versions of UUIDs, and when you should use them. Which UUID Version Should You Use? UUID v1, v4 and v5 Explained (With Examples) Updated on January 05, 2021
