Re: Parallel INSERT (INTO ... SELECT ...)

On Tue, Feb 9, 2021 at 1:04 AM Amit Langote <amitlangote09(at)gmail(dot)com> wrote:
>
> * I think that the concerns raised by Tsunakawa-san in:
>
> https://www.postgresql.org/message-id/TYAPR01MB2990CCB6E24B10D35D28B949FEA30%40TYAPR01MB2990.jpnprd01.prod.outlook.com
>
> regarding how this interacts with plancache.c deserve a look.
> Specifically, a plan that uses parallel insert may fail to be
> invalidated when partitions are altered directly (that is without
> altering their root parent). That would be because we are not adding
> partition OIDs to PlannerGlobal.invalItems despite making a plan
> that's based on checking their properties. See this (tested with all
> patches applied!):
>

Does any current Postgres code add partition OIDs to
PlannerGlobal.invalItems for a similar reason?
I would have thought that, for example, partitions with a default
column expression, using a function that is changed from SAFE to
UNSAFE, would suffer the same plancache issue (for current parallel
SELECT functionality) as we're talking about here - but so far I
haven't seen any code handling this.

(Currently invalItems seems to support PROCID and TYPEOID; relation
OIDs seem to be handled through a different mechanism)..
Can you elaborate on what you believe is required here, so that the
partition OID dependency is registered and the altered partition
results in the plan being invalidated?
Thanks in advance for any help you can provide here.

Regards,
Greg Nancarrow
Fujitsu Australia