Horton

Re: ALTER TABLE .. DETACH PARTITION CONCURRENTLY

Amit Langote <amitlangote09@gmail.com>

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From: Amit Langote <amitlangote09@gmail.com>
To: Pavel Luzanov <p.luzanov@postgrespro.ru>
Cc: Álvaro Herrera <alvherre@alvh.no-ip.org>, Justin Pryzby <pryzby@telsasoft.com>, Tom Lane <tgl@sss.pgh.pa.us>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>
Date: 2021-05-06T05:35:34Z
Lists: pgsql-hackers

Attachments

On Wed, May 5, 2021 at 7:59 PM Pavel Luzanov <p.luzanov@postgrespro.ru> wrote:
> I found this in the documentation, section '5.11.3. Partitioning Using Inheritance'[1]:
> "Some operations require a stronger lock when using declarative partitioning than when using table inheritance. For example, removing a partition from a partitioned table requires taking an ACCESS EXCLUSIVE lock on the parent table, whereas a SHARE UPDATE EXCLUSIVE lock is enough in the case of regular inheritance."
>
> This point is no longer valid with some restrictions. If the table has a default partition, then removing a partition still requires taking an ACCESS EXCLUSIVE lock.
>
> May be make sense to add some details about DETACH CONCURRENTLY to the section '5.11.2.2. Partition Maintenance' and completely remove this point?
>
> 1. https://www.postgresql.org/docs/devel/ddl-partitioning.html#DDL-PARTITIONING-USING-INHERITANCE

That makes sense, thanks for noticing.

How about the attached?

-- 
Amit Langote
EDB: http://www.enterprisedb.com

Commits

  1. Make detach-partition-concurrently-4 less timing sensitive

  2. Improve documentation on DETACH PARTITION lock levels

  3. Track detached partitions more accurately in partdescs

  4. Allow a partdesc-omitting-partitions to be cached

  5. Fix relcache inconsistency hazard in partition detach

  6. Don't add a redundant constraint when detaching a partition

  7. ALTER TABLE ... DETACH PARTITION ... CONCURRENTLY

  8. Let ALTER TABLE Phase 2 routines manage the relation pointer

  9. Check default partitions constraints while descending