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UUIDs explained

  • Universal Unique ID
  • aka GUID
    • Global Unique ID

TLDR - use v4 unless there's specific scenarios

UUID v1

  • MAC address + current datetime
    • 71226380-06c0-11ed-8d75-e9e11a03a4b7
  • UUID v1 generated a few seconds later
    • 7c2e73e0-06c0-11ed-8d75-e9e11a03a4b7
  • guarantee that there's random
  • really nice for database indexing

UUID v4

  • random numbers
  • unlikely there's a conflict (2^128)

UUID v5

UUIDv5(namespace_uuid, text) uuidv5.png

avoiding rainbow table attacks by using UUIDv5 as a salt for passwords


Last update: 2022-09-23