Re: Avoid computing ORDER BY junk columns unnecessarily

Heikki Linnakangas <hlinnaka@iki.fi> writes:
> On 22/12/2023 17:24, Tom Lane wrote:
>> How much of your patchset still makes sense if we assume that we
>> can always extract the ORDER BY column values from the index?

> That would make it much less interesting. But I don't think that's a 
> good assumption. Especially in the kNN case, the ORDER BY value would 
> not be stored in the index. Most likely the index needs to calculate it 
> in some form, but it might take shortcuts like avoiding the sqrt().

Yeah, fair point.  I'll try to take a look at your patchset after
the holidays.

            regards, tom lane