Re: Hooking into ExplainOneQuery() complicated by missing standard_ExplainOneQuery

Andrei Lepikhov <a.lepikhov@postgrespro.ru>

From: Andrei Lepikhov <a.lepikhov@postgrespro.ru>
To: Michael Paquier <michael@paquier.xyz>, Mats Kindahl <mats@timescale.com>
Cc: Aleksander Alekseev <aleksander@timescale.com>, pgsql-hackers@lists.postgresql.org
Date: 2024-03-06T02:26:49Z
Lists: pgsql-hackers
On 6/3/2024 06:25, Michael Paquier wrote:
>> Just to elaborate: the intention was to allow a section to be added to
>> every node in the plan containing information from further down and also
>> allow this information to propagate upwards. We happen to have buffer
>> information right now, but allowing something similar to be added
>> dynamically by extending ExplainNode and passing down a callback to
>> standard_ExplainOneQuery.
> 
> Or an extra hook at the end of ExplainNode() to be able to append more
> information at node level?  Not sure if others would agree with that,
> though.

We already discussed EXPLAIN hooks, at least in [1]. IMO, extensions 
should have a chance to add something to the node explain and the 
summary, if only because they can significantly influence the planner 
and executor's behaviour.

[1] 
https://www.postgresql.org/message-id/flat/6cd5caa7-06e1-4460-bf35-00a59da3f677%40garret.ru

-- 
regards,
Andrei Lepikhov
Postgres Professional




Commits

  1. Improve support for ExplainOneQuery() hook