MongoDB Memo Issue 78: January 22, 2021 より。
MongoDB ObjectIds Now Start with 6 — This is pointless trivia, but ObjectIds are formed from Unix epoch timestamp values plus a random value and a incrementing counter. Due to the current time since 1970, ObjectIds now start with 6 rather than 5. You’ll need to wait till 2029 until the 7s begin. Generate some ObjectIds here!
WES BOS ON TWITTER
仕事で7年間 MongoDB を使ってた間はずっと 5 始まりの ObjectId だったので、ちょっと感慨深い。
> ObjectId()
ObjectId("600fd00472eee4f6d36eea55")