Horton

Re: pg_dump is broken for partition tablespaces

David Rowley <david.rowley@2ndquadrant.com>

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From: David Rowley <david.rowley@2ndquadrant.com>
To: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, Robert Haas <robertmhaas@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2019-04-23T11:03:16Z
Lists: pgsql-hackers 
On Tue, 23 Apr 2019 at 18:18, Amit Langote
<Langote_Amit_f8@lab.ntt.co.jp> wrote:
>
> If partitions needed a
> map in the old database, this patch means that they will *continue* to
> need it in the new database.

That's incorrect.  My point was about dropped columns being removed
after a dump / reload.  Only binary upgrade mode preserves
pg_attribute entries for dropped columns. Normal mode does not, so the
maps won't be needed after the reload if they were previously only
needed due to dropped columns.  This is the case both with and without
the pg_dump changes I proposed.  The case the patch does change is if
the columns were actually out of order, which I saw as an unlikely
thing to happen in the real world.

-- 
 David Rowley                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

Commits

  1. Make pg_dump emit ATTACH PARTITION instead of PARTITION OF (reprise)

  2. Fix tablespace inheritance for partitioned rels

  3. Make pg_dump emit ATTACH PARTITION instead of PARTITION OF

  4. Make sure ALTER TABLE preserves index tablespaces.