Martijn van Oosterhout <kleptog@svana.org> writes:
> But a period type will take just one or two more bytes if you don't
> require alignment. Alignment on a varlena type seems silly anyway,
> since you'll be aligning the header byte rather than the content.
You might still end up paying the alignment overhead after the field,
of course. But avoiding embedding the alignment in the type itself
seems worth doing.
One idea that might be interesting to consider in this regard is
force-packing varlena range values. Consider a text range('a', 'b').
The datums are likely to come in with 4-byte headers requiring
alignment. If we have the smarts to force them to 1-byte header form
inside the varlena range value, not only do we save bytes right there,
but we don't have to expend cycles to copy them somewhere to re-align
them before we can pass them to the datatype-specific functions.
regards, tom lane