elein <elein@sbcglobal.net> writes:
> According to the documentation, it looks like sequences
> are always stored as bigints (if the platform supports them).
Correct.
> Serials, though, seem to be able to be declared as serial
> with integer storage or serial8 for bigint storage.
> Is the storage for ordinary serials really an int and not
> a big int?
If you declare a serial (aka serial4) column, you get an int4 column
that's driven by a bigint sequence. No problem except for a runtime
conversion from int8 to int4, which is really pretty negligible in
comparison to the cost of nextval().
> Is there a way to create a sequence stored as an int instead of a big
> int?
No; it wouldn't save anything anyway, seeing that each sequence is
stored as a separate table and so must occupy one disk block.
regards, tom lane