Horton

Re: CLUSTER on partitioned index

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Justin Pryzby <pryzby@telsasoft.com>, Michael Paquier <michael@paquier.xyz>, 李杰(慎追) <adger.lj@alibaba-inc.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, 曾文旌(义从) <wenjing.zwj@alibaba-inc.com>, Zhihong Yu <zyu@yugabyte.com>
Date: 2022-03-31T12:39:19Z
Lists: pgsql-hackers 
On Thu, Mar 31, 2022 at 6:54 AM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> I realized after posting that we used to allow clustering toast tables,
> but after my changes we no longer do.  (Justin's version had a
> RELKIND_HAS_STORAGE test here instead, which seemed a little too lax.) I
> don't know why we allowed it and I don't know of anyone who has ever
> used that feature and we don't have any test coverage for it, but I
> don't have any reason to explicitly disallow it either.  So I propose to
> continue to allow it:

I think that's probably a good decision. It's certainly useful to have
a way to force a rewrite of a TOAST table, although a lot of people
who would benefit from that operation probably don't know that they
need it, or don't know that they need just that, and end up rewriting
both the main table and the TOAST table. Whether it's useful to be
able to run CLUSTER specifically rather than VACUUM FULL on the TOAST
table is less clear, but I don't think we're likely to save anything
by forbidding it. Maybe we should consider adding a test, though.

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

Commits

  1. Add some isolation tests for CLUSTER

  2. Have CLUSTER ignore partitions not owned by caller

  3. Remove "recheck" argument from check_index_is_clusterable()

  4. Allow CLUSTER on partitioned tables

  5. doc: Add backlinks to progress reporting documentation