Horton

Re: pg_dump versus hash partitioning

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andrew Dunstan <andrew@dunslane.net>, Alvaro Herrera <alvherre@alvh.no-ip.org>, David Rowley <dgrowleyml@gmail.com>, Peter Geoghegan <pg@bowt.ie>, pgsql-hackers@lists.postgresql.org, Andrew <pgsqlhackers@andrewrepp.com>
Date: 2023-02-27T15:50:42Z
Lists: pgsql-hackers 
On Tue, Feb 14, 2023 at 2:21 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> This made me wonder if this could be a usable solution at all, but
> after thinking for awhile, I don't see how the claim about foreign key
> constraints is anything but FUD.  pg_dump/pg_restore have sufficient
> dependency logic to prevent that from happening.  I think we can just
> drop the "or perhaps ..." clause here, and tolerate the possible
> inefficiency as better than failing.

Right, but isn't that dependency logic based around the fact that the
inserts are targeting the original partition? Like, suppose partition
A has a foreign key that is not present on partition B. A row that is
originally in partition B gets rerouted into partition A. It must now
satisfy the foreign key constraint when, previously, that was
unnecessary.

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

Commits

  1. Simplify and speed up pg_dump's creation of parent-table links.

  2. Fix pg_dump for hash partitioning on enum columns.