Thread

Re: [GENERAL] pg_upgrade problem

Bruce Momjian <bruce@momjian.us> — 2011-09-07T01:21:02Z

Tom Lane wrote:
> hubert depesz lubaczewski <depesz@depesz.com> writes:
> > Worked a bit to get the ltree problem down to smallest possible, repeatable, situation.
> 
> I looked at this again and verified that indeed, commit
> 8eee65c996048848c20f6637c1d12b319a4ce244 introduced an incompatible
> change into the on-disk format of ltree columns: it widened
> ltree_level.len, which is one component of an ltree on disk.
> So the crash is hardly surprising.  I think that the only thing
> pg_upgrade could do about it is refuse to upgrade when ltree columns
> are present in an 8.3 database.  I'm not sure though how you'd identify
> contrib/ltree versus some random user-defined type named ltree.

It is actually easy to do using the attached patch.  I check for the
functions that support the data type and check of they are from an
'ltree' shared object.  I don't check actual user table type names in
this case.

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

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