On 05/27/2012 06:40 AM, Bruce Momjian wrote:
On Fri, May 25, 2012 at 11:08:10PM -0400, Bruce Momjian wrote:
On Fri, May 25, 2012 at 10:20:29AM -0400, Andrew Dunstan wrote:
pg_upgrade is a little over-keen about checking for shared libraries
that back functions. In particular, it checks for libraries that
support functions created in pg_catalog, even if pg_dump doesn't
export the function.
The attached patch mimics the filter that pg_dump uses for functions
so that only the relevant libraries are checked.
This would remove the need for a particularly ugly hack in making
the 9.1 backport of JSON binary upgradeable.
Andrew is right that pg_upgrade is overly restrictive in checking _any_
shared object file referenced in pg_proc. I never expected that
pg_catalog would have such references, but in Andrew's case it does, and
pg_dump doesn't dump them, so I guess pg_upgrade shouldn't check them
either.
In some sense this is a hack for the JSON type, but it also gives users
a way to create shared object references in old clusters that are _not_
checked by pg_upgrade, and not migrated to the new server, so I suppose
it is fine.
OK, now I know it is _not_ fine. :-(
I just realized the problem as part of debugging the report of a problem
with plpython_call_handler():
http://archives.postgresql.org/pgsql-hackers/2012-03/msg01101.php
http://archives.postgresql.org/pgsql-bugs/2012-05/msg00205.php
The problem is that functions defined in the "pg_catalog" schema, while
no explicitly dumped by pg_dump, are implicitly dumped by things like
CREATE LANGUAGE plperl.
I have added a pg_upgrade C comment documenting this issue in case we
revisit it later.
"things like CREATE LANGUAGE plperl" is a rather vague phrase. The PL
case could be easily handled by adding this to the query:
OR EXISTS (SELECT 1 FROM pg_catalog.pg_language WHERE lanplcallfoid
= p.oid)
Do you know of any other cases that this would miss?
The fact is that unless we do something like this there is a potential
for unnecessary pg_upgrade failures. The workaround I am currently using
for the JSON backport of having to supply a dummy shared library is
almost unspeakably ugly. If you won't consider changing the query, how
about an option to explicitly instruct pg_upgrade to ignore a certain
library in its checks?
cheers
andrew
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
