Andrei Lepikhov писал(а) 2025-05-07 12:03:
On 7/5/2025 08:57, Alexander Pyhalov wrote:
Andrei Lepikhov писал(а) 2025-05-07 08:02:
On 5/5/2025 15:56, Alexander Pyhalov wrote:
Andrei Lepikhov писал(а) 2025-05-05 14:38:
Also logic a bit differs if path is NULL. In
get_cheapest_path_for_pathkeys_ext() we explicitly check for path
being NULL, in get_cheapest_fractional_path_for_pathkeys_ext() only
after calculating sort cost.
I've tried to fix comments a bit and unified functions definitions.
Generally seems ok, I'm not a native speaker to judge the comments.
But:
if (base_path && path != base_path)
What is the case in your mind where the base_path pointer still may
be null at that point?
Hi.
It seems if some childrel doesn't have valid pathlist, subpaths_valid
would be false in add_paths_to_append_rel()
and generate_orderedappend_paths() will not be called. So when we
iterate over live_childrels,
all of them will have cheapest_total path. This is why we can assert
that base_path is not NULL.
I'm not sure I understand you correctly. Under which conditions will
rel->cheapest_total_path be set to NULL for a childrel? Could you
provide an example?
Sorry, perhaps I was not clear enough. I've stated the opposite - it
seems we can be sure that it's not NULL.
--
Best regards,
Alexander Pyhalov,
Postgres Professional
