Re: Improving EXPLAIN's display of SubPlan nodes - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Improving EXPLAIN's display of SubPlan nodes
Date
Msg-id 3791430.1705943243@sss.pgh.pa.us
Whole thread Raw
In response to Re: Improving EXPLAIN's display of SubPlan nodes  (Aleksander Alekseev <aleksander@timescale.com>)
Responses Re: Improving EXPLAIN's display of SubPlan nodes
Re: Improving EXPLAIN's display of SubPlan nodes
List pgsql-hackers
Aleksander Alekseev <aleksander@timescale.com> writes:
> Although something like:

> ```
> +   Filter: (ANY (base_tbl.a = $1) FROM SubPlan 1 (returns $1))
> +   SubPlan 1 (returns $1)
> ```

> ... arguably doesn't give much more information to the user comparing
> to what we have now:

> ```
> -   Filter: (SubPlan 1)
> -   SubPlan 1
> ```

Yeah, I would probably not have thought to do this on my own; but
we had an actual user request for it.  I think arguably the main
benefit is to confirm "yes, this is the sub-select you think it is".

The main thing that's still missing compared to what is in the plan
data structure is information about which Param is which.  I think
we have the subplan output Params relatively well covered through
the expedient of listing them in the generated plan_name, but it's
still not apparent to me how we could shoehorn subplan input
Params into this (or whether it's worth doing).

            regards, tom lane



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