On 8/2/2025 04:28, Ilia Evdokimov wrote:
> On 08.02.2025 00:01, Matheus Alcantara wrote:
>> Just for reference I'm trying to apply based on commit fb056564ec5.
> You are right, because two commits were appeared after creating v6-patch
> on partition_prune.out and patch v6 must not have applied on master.
> Then I created v7 patch rebased on fb056564ec5 . Thank for your remark!
I support the idea in general, but I believe it should be expanded to
cover all cases of parameterised plan nodes. Each rescan iteration may
produce a different number of tuples, and rounding can obscure important
data.
For example, consider five loops of a scan node: the first loop returns
nine tuples, and each other - zero tuples. When we calculate the
average, 9 divided by 5 equals 1.8. This results in an explanation that
indicates "rows = 1," masking almost 40% of the data.
Now, if we apply the same two loops but have a total of 900,000 tuples,
then 400,000 masked tuples represent a significant portion of the data.
Moreover, switching to a floating-point type for row explanations in
each parameterised node would provide a more comprehensive view and add
valuable information about the parameterisation of the node, which may
not be immediately apparent.
--
regards, Andrei Lepikhov
