Re: Incremental sort for access method with ordered scan support (amcanorderbyop) - Mailing list pgsql-hackers

On Thu, 20 Apr 2023 at 18:46, Richard Guo <guofenglinux@gmail.com> wrote:
>
>
> On Thu, Apr 20, 2023 at 6:38 AM David Rowley <dgrowleyml@gmail.com> wrote:
>>
>> That function is pretty new and was exactly added so we didn't have to
>> write list_truncate(list_copy(...), n) anymore.  That gets pretty
>> wasteful when the input List is long and we only need a small portion
>> of it.
>
> I searched the codes and found some other places where the manipulation
> of lists can be improved in a similar way.

I'd be happy to discuss our thought about List inefficiencies, but I
think to be fair to Miroslav, we should do that somewhere else. The
list_copy_head() discussion was directly related to his patch due to
the list of list_truncate(list_copy(..), ..).  The other things you've
mentioned are not.  Feel free to start a thread and copy me in.

David