I have to admit this is over my head. But sometimes being stupid also what works, and I've always abided by the old adage that "it's better to have a tractor that works than a limo that you can't get out of the garage". I realize that in this case maybe the problem was just a pretext for demonstrating HyperLogLog, but in case someone is looking for a simple solution to this very problem maybe this naïve solution could work (use at your own peril!):
So I'd create an associated table that records the user, time and object viewed, and a field with the rolled up count on the object record. The problem with duplicate views is solved by wrapping the insert and the upping of the counter in the same transaction: if the insert fails because of a breach of the unique index then the upping fails too.
So I'd create an associated table that records the user, time and object viewed, and a field with the rolled up count on the object record. The problem with duplicate views is solved by wrapping the insert and the upping of the counter in the same transaction: if the insert fails because of a breach of the unique index then the upping fails too.
I probably missed something?