Re: Improving EXPLAIN's display of SubPlan nodes

Hi Aleksander and Tom

I do confirm that I requested to get this information, in order to
recover the formula to filter on.

Thanks to both of you
Chantal




Le 22/01/2024 à 18:07, Tom Lane a écrit :
> 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