Re: pg_sequence catalog

I wrote:
> Personally, my big beef with the current approach to sequences is that
> we eat a whole relation (including a whole relfilenode) per sequence.
> I wish that we could reduce a sequence to just a single row in a
> catalog, including the nontransactional state. Not sure how feasible
> that is either, but accomplishing it would move the benefits of making
> a change out of the "debatable whether it's worth it" category, IMO.

BTW, another thing to keep in mind here is the ideas that have been
kicked around in the past about alternative sequence implementations
managed through a "sequence AM API". I dunno whether now is the time
to start creating that API abstraction, but let's at least consider
it if we're whacking the catalog representation around.

regards, tom lane