Re: pg_upgrade 9.4 -> 9.5 with pg_trgm fails for me

On 01/08/2016 01:26 PM, Tom Lane wrote:
> Karsten Hilbert <Karsten.Hilbert@gmx.net> writes:
>> On Fri, Jan 08, 2016 at 04:03:51PM -0500, Tom Lane wrote:
>>> BTW, the one-liner fix that I'd had in mind when I wrote that does indeed
>>> fix this particular problem, but after studying the code I realized that
>>> there's a whole bunch of related problems; for instance I believe
>>> pg_upgrade would lose domain constraints on a domain type that's in an
>>> extension installed into pg_catalog :-(.
>
>> Does this warrant adding a few words to the documentation
>> warning against installing extensions into pg_catalog. ?
>
> No, it's just a bug.  Although apparently not many people do that, or
> we'd have heard complaints before.

That dredged up a memory from way back:

http://www.postgresql.org/message-id/200411251906.43881.aklaver@comcast.net

in particular:

http://www.postgresql.org/message-id/20077.1101510670@sss.pgh.pa.us

>
>             regards, tom lane
>
>


--
Adrian Klaver
adrian.klaver@aklaver.com