> The most significant impact is that it takes up twice as much space,
> including the primary key index. This means fewer entries per block,
> which means slower scans and/or more blocks to navigate through. Still,
> compared to the rest of the overhead of an index row or a table row, it
> is low - I think it's more important to understand whether you can get
> away with using a sequential integer, in which case UUID is unnecessary
> overhead - or whether you are going to need UUID anyways. If you need
> UUID anyways - having two primary keys is probably not worth it.
Ok, that's what I was hoping. Out of curiosity, is there a preferred
way to store 256-bit ints in postgres? At that point, is a bytea the
most reasonable choice, or is there a better way to do it?
