Bruce Momjian wrote:
> On Tue, Mar 21, 2017 at 04:43:58PM -0300, Alvaro Herrera wrote:
> > Bruce Momjian wrote:
> >
> > > I don't think it makes sense to try and save bits and add complexity
> > > when we have no idea if we will ever use them,
> >
> > If we find ourselves in dire need of additional bits, there is a known
> > mechanism to get back 2 bits from old-style VACUUM FULL. I assume that
> > the reason nobody has bothered to write the code for that is that
> > there's no *that* much interest.
>
> We have no way of tracking if users still have pages that used the bits
> via pg_upgrade before they were removed.
Yes, that's exactly the code that needs to be written.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services