Re: FOR EACH ROW triggers on partitioned tables - Mailing list pgsql-hackers

From Amit Langote
Subject Re: FOR EACH ROW triggers on partitioned tables
Date
Msg-id f943ba0c-3180-37a9-c12c-1aa5e63e1a9b@lab.ntt.co.jp
Whole thread Raw
In response to Re: FOR EACH ROW triggers on partitioned tables  (Alvaro Herrera <alvherre@alvh.no-ip.org>)
List pgsql-hackers
On 2018/02/16 6:55, Alvaro Herrera wrote:
> Amit Langote wrote:
>> On 2018/02/15 6:26, Alvaro Herrera wrote:
>>> Another option is to rethink this feature from the ground up: instead of
>>> cloning catalog rows for each children, maybe we should have the trigger
>>> lookup code, when running DML on the child relation (the partition),
>>> obtain trigger entries not only for the child relation itself but also
>>> for its parents recursively -- so triggers defined in the parent are
>>> fired for the partitions, too.  I'm not sure what implications this has
>>> for constraint triggers.
>>>
>>> The behavior should be the same, except that you cannot modify the
>>> trigger (firing conditions, etc) on the partition individually -- it
>>> works at the level of the whole partitioned table instead.
>>
>> Do you mean to fire these triggers only if the parent table (not a child
>> table/partition) is addressed in the DML, right?  If the table directly
>> addressed in the DML is a partition whose parent has a row-level trigger,
>> then that trigger should not get fired I suppose.
> 
> No, I think that would be strange and cause data inconsistencies.
> Inserting directly into the partition is seen as a performance
> optimization (compared to inserted into the partitioned table), so we
> don't get to skip firing the triggers defined on the parent because the
> behavior would become different.  In other words, the performance
> optimization breaks the database.

OK, that makes sense.

Thanks,
Amit



pgsql-hackers by date:

Previous
From: Amit Langote
Date:
Subject: Re: non-bulk inserts and tuple routing
Next
From: Etsuro Fujita
Date:
Subject: Re: non-bulk inserts and tuple routing