That depends a lot on many factors and thus I dont like generic statements like that which tend to be more focused on a specific database pattern. That said everyone should indeed be aware of the potential tradeoffs.

And of course we could come up with many ways to generate our own ids and make them unique, but we have the following requirements.

- It needs to be a string (because we allow composing them to 'derive' keys) - A client must be able to create them (not just a server) without risk for collisions - The time order of keys must not be guessable easily (as the id is often leaked via references which could 'betray' not just the existence of a document, but also its relative creation time wrt others). - It should be easy to document how any client can safely generate document ids.

The lookup performance is not really such a big deal for us. Where it is we can do a projection into a more simple format where applicable.