Re: pg15b2: large objects lost on upgrade

On Fri, Jul 29, 2022 at 7:16 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> That's not the only thing weird about this printout: there should be
> three columns not two in that query's output, and what happened to
> the trailing newline? I don't think we're looking at desired
> output at all.

Well, that's an awfully good point.

> I am suspicious that the problem stems from the nonstandard
> way you've invoked psql to collect the horizon data. At the very
> least this code is duplicating bits of Cluster::psql that it'd be
> better not to; and I wonder if the issue is that it's not duplicating
> enough. The lack of -X and the lack of use of installed_command()
> are red flags. Do you really need to do it like this?

Well, I just copied the pg_dump block which occurs directly beforehand
and modified it. I think that must take care of setting the path
properly, else we'd have things blowing up all over the place. But the
lack of -X could be an issue.

The missing newline thing happens for me locally too, if I revert the
bug fix portion of that commit, but I do seem to get the right columns
in the output. It looks like this:

19:24:16.057](0.000s) not ok 16 - old and new horizons match after pg_upgrade
[19:24:16.058](0.000s)
[19:24:16.058](0.000s) # Failed test 'old and new horizons match
after pg_upgrade'
# at t/002_pg_upgrade.pl line 345.
[19:24:16.058](0.000s) # got: '1'
# expected: '0'
=== diff of /Users/rhaas/pgsql/src/bin/pg_upgrade/tmp_check/tmp_test_K8Fs/horizon1.txt
and /Users/rhaas/pgsql/src/bin/pg_upgrade/tmp_check/tmp_test_K8Fs/horizon2.txt
=== stdout ===
1c1
< pg_largeobject|718|1
---
> pg_largeobject|17518|3=== stderr ===
=== EOF ===
[19:24:16.066](0.008s) 1..16

I can't account for the absence of a newline there, because hexdump
says that both horizon1.txt and horizon2.txt end with one, and if I
run diff on those two files and pipe the output into hexdump, it sees
a newline at the end of that output too.

--
Robert Haas
EDB: http://www.enterprisedb.com