Re: SSI patch renumbered existing 2PC resource managers??

Bruce Momjian wrote:
> > This argument seems a tad peculiar, since the *entire* *point* of
> > pg_upgrade is to push physical files from one installation into another
> > even though compatibility isn't guaranteed.  It is the program's duty to
> > understand enough to know whether it can transport the cluster's state
> > safely.  Not to arbitrarily discard state because it might possibly not
> > be transportable.
> 
> Well, pg_upgrade succeeds because it does as little as necessary to do
> the migration, relying on pg_dump to do much of the migration work at
> the catalog level.  pg_upgrade tries to be involved as little as
> possible with the Postgres code so it doesn't have to be changed
> regularly between major versions.
> 
> The prepared transaction case seems ugly enough that we don't want
> pg_upgrade to have to check every major release if anything changed
> about the data stored in prepared transactions.  This is the same reason
> pg_upgrade doesn't transfer WAL files from the old cluster, just pg_clog
> files (which rarely changes its format).

I have applied the attached pg_upgrade patch to head and 9.1 to fail if
prepared transactions are in the old or new cluster.

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

  + It's impossible for everything to be true. +