Re: pg_dump versus hash partitioning

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Julien Rouhaud <rjuju123@gmail.com>, Andrew Dunstan <andrew@dunslane.net>, Alvaro Herrera <alvherre@alvh.no-ip.org>, David Rowley <dgrowleyml@gmail.com>, Peter Geoghegan <pg@bowt.ie>, Robert Haas <robertmhaas@gmail.com>, pgsql-hackers@lists.postgresql.org, Andrew <pgsqlhackers@andrewrepp.com>
Date: 2023-03-12T20:02:43Z
Lists: pgsql-hackers
Justin Pryzby <pryzby@telsasoft.com> writes:
> On Sun, Mar 12, 2023 at 03:46:52PM -0400, Tom Lane wrote:
>> What I propose we do about that is further tweak things so that
>> load-via-partition-root forces dumping via COPY.  AFAIK the only
>> compelling use-case for dump-as-INSERTs is in transferring data
>> to a non-Postgres database, which is a context in which dumping
>> partitioned tables as such is pretty hopeless anyway.  (I wonder if
>> we should have some way to dump all the contents of a partitioned
>> table as if it were unpartitioned, to support such migration.)

> I think that what this other thread is about.
> https://commitfest.postgresql.org/42/4130/
> pg_dump all child tables with the root table

As far as I understood (didn't actually read the latest patch) that
one is just about easily selecting all the partitions of a partitioned
table when doing a selective dump.  It's not helping you produce a
non-Postgres-specific dump.

Although I guess by combining load-via-partition-root, data-only mode,
and dump-as-inserts you could produce a clean collection of
non-partition-dependent INSERT commands ... so maybe we'd better not
force dump-as-inserts off.  I'm starting to like the te->defn hack
more.

			regards, tom lane



Commits

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

  2. Fix pg_dump for hash partitioning on enum columns.