Re: Page OpaqueData

Manfred Koizar <mkoi-pg@aon.at> writes:
> Is od_pagesize in any way more or less opaque than pd_lower, pd_upper,
> pd_special, etc?  If it is, why?

I surmise that there was once some idea of supporting multiple page
sizes simultaneously, but it's not real clear why the macros
PageGetPageSize/PageSetPageSize wouldn't be a sufficient abstraction
layer; the extra level of struct naming for pd_opaque has no obvious
usefulness.  In any case I doubt that dealing with multiple page sizes
would be worth the trouble it would be to support.

> If it's not, should I post a patch that puts pagesize directly into
> PageHeaderData?

If you're so inclined.  Given that pd_opaque is hidden in those macros,
there wouldn't be much of any gain in readability either, so I haven't
worried about changing the declaration.
        regards, tom lane