Re: jsonb format is pessimal for toast compression

On Mon, Sep 29, 2014 at 12:30:40PM -0400, Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> > On Thu, Sep 25, 2014 at 02:39:37PM -0400, Tom Lane wrote:
> >> BTW, it seems like there is consensus that we ought to reorder the items
> >> in a jsonb object to have keys first and then values, independently of the
> >> other issues under discussion.  This means we *will* be breaking on-disk
> >> compatibility with 9.4beta2, which means pg_upgrade will need to be taught
> >> to refuse an upgrade if the database contains any jsonb columns.  Bruce,
> >> do you have time to crank out a patch for that?
>
> > Yes, I can do that easily.  Tell me when you want it --- I just need a
> > catalog version number to trigger on.
>
> Done --- 201409291 is the cutover point.

Attached patch applied to head, and backpatched to 9.4.  I think we need
to keep this in all future pg_ugprade versions in case someone from the
beta tries to jump versions, e.g. 9.4 beta1 to 9.5.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + Everyone has their own god. +