Re: HOT patch - version 15

On 9/11/07, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> "Pavan Deolasee" <pavan(dot)deolasee(at)gmail(dot)com> writes:
> > I would actually think twice before even doing this because this would
> > lead to complete change in heap page structure and stop people from
> > upgrading to 8.3 without a complete dump/restore. I don't remember 8.3
> > introduces any other significant change which already enforces that.
>
> Then you don't remember far enough --- either the HeapTupleHeader change
> or the varvarlena change would be enough to prevent that. For that
> matter, the pd_flags header field that the patch is already relying on
> is new for 8.3.
>
>
Oops! I forgot combo command id. That went into last major release of EDB
and that confused me. Regarding pd_flags, I thought somebody can just
fix that in-place and avoid dump/restore (of course, its too invasive, but
isn't it feasible with pg_migrator ?)

Anyways, given this, should we go for storing xmin in the page header ?
For that matter should there be a separate heap page header ?

Thanks,
Pavan

--
Pavan Deolasee
EnterpriseDB http://www.enterprisedb.com