Horton

Re: partitioned tables referenced by FKs

Alvaro Herrera <alvherre@2ndquadrant.com>

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From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Jesper Pedersen <jesper.pedersen@redhat.com>
Cc: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2019-03-29T15:22:39Z
Lists: pgsql-hackers 
On 2019-Mar-29, Jesper Pedersen wrote:

> Could expand a bit on the change to DEPENDENCY_INTERNAL instead of
> DEPENDENCY_PARTITION_PRI / DEPENDENCY_PARTITION_SEC ?

The PARTITION dependencies work in a way that doesn't do what we want.
Admittedly, neither does INTERNAL, but at least it's less bad.

> If you run "DROP TABLE t2_p32 CASCADE" the foreign key constraint is removed
> from all of t1.

Yes.  CASCADE is always a dangerous tool; if you run the DROP partition
without cascade, it explicitly lists that the constraint is going to be
dropped.

If you get in the habit of added CASCADE to all your drops, you're going
to lose data pretty quickly.  In this case, no data is lost, only a
constraint.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Support foreign keys that reference partitioned tables

  2. Fix partitioned index creation bug with dropped columns

  3. Improve psql's \d display of foreign key constraints

  4. Fix dependency recording bug for partitioned PKs

  5. Add index_get_partition convenience function

  6. Restore RI trigger sanity check

  7. Foreign keys on partitioned tables