Depends how you query it. In a lot of systems, recently added data is also the most queried data or data typically gets pulled out sorted by time. Having that data on disk in more or less the order it is going to be queried makes sorting it a bit easier. Even in a sharded system, each of the shards would have less work to do for sorting. Of course a lot of these systems would have an append only write model which would effectively sort things by time anyway, even with completely random ids.
Somebody posted an interesting article for the instagram ids, which do something similar. They use 41 bits for a time from a custom epoch followed two more groups of bits for a shard id and a sequential number. Each shard has an incrementing sequence for the sequential bit, which guarantees that things on a shard are sorted by time.
This UUIDv7 is slightly weaker than that but sorting things published in the same millisecond is mostly going to be very light work. The lack of a dedicated sharding group of bits is not that important as you could just take the n least significant bits at the end for that without too much effort. Those are random so you end up with nice consistent hashing. Having 48 instead of 41 bits for the time means we won't run out of time any time soon (nearly 9K years vs. 70 years).
Somebody posted an interesting article for the instagram ids, which do something similar. They use 41 bits for a time from a custom epoch followed two more groups of bits for a shard id and a sequential number. Each shard has an incrementing sequence for the sequential bit, which guarantees that things on a shard are sorted by time.
This UUIDv7 is slightly weaker than that but sorting things published in the same millisecond is mostly going to be very light work. The lack of a dedicated sharding group of bits is not that important as you could just take the n least significant bits at the end for that without too much effort. Those are random so you end up with nice consistent hashing. Having 48 instead of 41 bits for the time means we won't run out of time any time soon (nearly 9K years vs. 70 years).