Log tables with pkey on date can be searched faster in typical log table use of "tell me what happened in this time range", tho of course you have to make it unique
I'd rather logs not fail because for some weird reason the date of 2 records is exactly the same.
Time savings adjustments / clock drift correction sound like the most obvious candidate to produce such a case. Granted, chances are not high, but I'd usually prefer knowing that the chance of it failing for this reason is 0.
1) But with quite a hefty penalty on writes... I'd think you would be better off without a primary key and just using a BRIN index for that use case?
2) Even if you did really want that B-tree, you can still have it and not have to have to awkwardly make it unique if you don't make it a "primary" key.
