[SOLVED] UUID vs Long primary key

UUID vs Long primary key

In database design, when considering a primary key, what are the advantages and disadvantages of using UUID compared to a Long data type?

I came across two different tutorials that implemented each of them, and I am just curious about which one serves better.

Solution

Compare UUID and Long as the type of primary key in database:

1. Long:

Long or BigInt is 64-bit, less than UUID (128-bit).
Long is faster to generate, always generate unique ID, but not random. For example, in Spring Boot:
```
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
```

This code will generate an increasing-from-0 key. For example: 0, 1, 2, .... Of course, an increasing-from-0 key won't be safe against something like XSS (because of its easy-to-predict property).

2. UUID:

UUID is 128-bit, more than Long (64-bit).
Like Long, UUID always generate unique ID (like 558012d6-7db5-4053-b838-6a1ef4ad019b), but it's random, a bit slower and much harder to predict. This means it's more secure than Long.

In summary, both are good to use as the primary key in database. I think UUID is better, but I prefer to use Long because it's easier to implement in the program.