Horton

Re: pg_dump: sortDumpableObjectsByTypeName() doesn't always do that

Jacob Champion <pchampion@pivotal.io>

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From: Jacob Champion <pchampion@pivotal.io>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Date: 2018-08-06T19:23:59Z
Lists: pgsql-hackers 
On Mon, Aug 6, 2018 at 12:13 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Do you mean "incorrect results", or just "unstable results"?
> If the former, what's incorrect about it?

Incorrect, as in "the results are not sorted by type name." Here's an
example ordering that we saw -- but note that you won't be able to
repro since it relies on the Greenplum bug I mentioned.

...
pg_catalog.xlogloc_ops
public._tmp_table
public.a
public.a_star
<null>.abstime date
<null>.abstime int4
<null>.abstime time
<null>.abstime timestamp
<null>.abstime timestamptz
gporca_faults.foo
...

You can see the inversion between public._tmp_table (which is TABLE
DATA) and gporca_faults.foo (which is also TABLE DATA). I can try to
work on a Postgres-specific test case if you'd like, but since the
root cause is that we're not defining a valid ordering, quicksort may
or may not behave consistently for test purposes. We got "lucky" here;
otherwise we'd never have noticed.

--Jacob

Commits

  1. Ensure pg_dump_sort.c sorts null vs non-null namespace consistently.

  2. Last-minute updates for release notes.