Re: Considering fractional paths in Append node

Nikita Malakhov <hukutoc@gmail.com> writes:

> Hi,
>
> Andy, your words make sense, but to me it seems that in add_paths_to_append_rel
> we have no other options than tuple_fraction from root, and rows (if any) in paths
> we take into account, please correct me if I am wrong.

One of the option might be applying your logic only if we can prove the
tuple_fraction from root is same as the tuple_fraction, similar with
what I did before. But it is proved that is too complex. 

> Thank you!
>
> Also, on top of that I have an idea of pruning unnecessary partitions
> in generate_orderedappend_paths() when we have a valid LIMIT value.
> I'm currently checking if it is working correctly in multiple cases,
> so 'll send it after we deal with this issue.

-- 
Best Regards
Andy Fan