Re: Add comments about fire_triggers argument in ri_triggers.c

From: Amit Langote <amitlangote09(at)gmail(dot)com>
To: Yugo Nagata <nagata(at)sraoss(dot)co(dot)jp>
Cc: surya poondla <suryapoondla4(at)gmail(dot)com>, pgsql-hackers(at)postgresql(dot)org, Kirill Reshke <reshkekirill(at)gmail(dot)com>
Subject: Re: Add comments about fire_triggers argument in ri_triggers.c
Date: 2026-03-27 00:39:17
Message-ID: CA+HiwqGFuhuSus8L7O36CYoeeZtGJ4PO0cR94qKDbtMKR4T2OA@mail.gmail.com
Views: Whole Thread | Raw Message | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Fri, Mar 27, 2026 at 12:56 AM Yugo Nagata <nagata(at)sraoss(dot)co(dot)jp> wrote:
>
> Hi,
>
> Thank you all for the review and comments.
>
> > Yes Amit, I agree that SPI_execute_snapshot() comments do provide some
> > context on AFTER triggers, but I still feel the newly added comment
> > in ri_PerformCheck() gives additional context on why the fire_triggers is
> > set to false.
>
> Yes, that is what I intended. The existing comments on
> SPI_execute_snapshot() explain how the fire_triggers parameter works,
> but I would like to add a comment explaining why the AFTER trigger for
> RI needs to set it to false.
>
> If the explanation of the effect of fire_triggers seems redundant, I am
> fine with the following shorter version:
>
> + * Set fire_triggers to false to ensure that check triggers fire after all
> + * RI updates on the same row are complete.

Thanks for the updated patch. Yes, adding the comment might be good,
but I'd suggest a small tweak:

+ * Set fire_triggers to false to ensure that AFTER triggers
are queued in
+ * the outer query's after-trigger context and fire after all
RI updates on
+ * the same row are complete, rather than immediately.

Two changes:

* "check triggers" -> "AFTER triggers", since fire_triggers=false
affects any AFTER triggers queued during the SPI execution, not just
RI check triggers.

* mention of the outer query's after-trigger context to explain the
mechanism by which the deferral works.

Does that additional context help?

--
Thanks, Amit Langote

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message John Naylor 2026-03-27 00:45:37 Re: Adjust error message for CREATE STATISTICS to account for expressions
Previous Message SATYANARAYANA NARLAPURAM 2026-03-27 00:29:25 [Proposal] pg_stat_wal_records – per-record-type WAL generation statistics