Re: reloption to prevent VACUUM from truncating empty pages at the end of relation

Robert Haas <robertmhaas@gmail.com> writes:
> I want to make one other point about this patch, which is that over on
> the thread "New vacuum option to do only freezing" we have a patch
> that does a closely-related thing.  Both patches skip one phase of the
> overall VACUUM process.  THIS patch wants to skip truncation; THAT
> patch wants to skip index cleanup.  Over there, we seem to have
> settled on DISABLE_INDEX_CLEANUP -- only available as a VACUUM option
> -- and here I think the proposal is currently VACUUM_SHRINK_ENABLED --
> only available as a reloption.

> Now that seems not very consistent.

Indeed, but I'm not sure that the use-cases are the same.  In particular,
unless somebody has done some rather impossible magic, it would be
disastrous to apply DISABLE_INDEX_CLEANUP as a reloption, because then
it would be persistent and you'd never get a real vacuum operation and
soon your disk would be full.  Permanently applying truncation disabling
seems less insane.

The gratuitously inconsistent spellings should be harmonized, for sure.

            regards, tom lane