Re: making EXPLAIN extensible

On Tue, Mar 18, 2025 at 8:02 AM Andrei Lepikhov <lepihov(at)gmail(dot)com> wrote:
> Some questions:
> 1. I think, hooks ExplainOneQuery_hook_type, explain_per_plan_hook_type,
> explain_per_node_hook_type deserve to be moved to explain_format.h
> At least, inside the hook, we usually use functions like ExplainProperty.

-1, because the hooks will be called from explain.c, not explain_state.c.

> 2. In my patch I inserted the hook before the line 1894:
> /* in text format, the first line ends here */
> Why have you chosen a different way? I don't have specific reasons to
> insist, except the extension data right under the node looks better to
> me personally.

Tom discusses why we shouldn't try to add to the first line in
http://postgr.es/m/2234935.1741809008@sss.pgh.pa.us and I'm fully in
agreement.

I've committed 0001 and 0002 for now. The additional hook for
cross-option validation can be added in a separate commit. v6-0003,
now v7-0001, needs more substantive review before commit. I hope it
gets some, and soon.

--
Robert Haas
EDB: http://www.enterprisedb.com