On 8/29/18 1:38 PM, Robert Haas wrote:
> On Mon, Aug 27, 2018 at 6:05 PM, Jonathan S. Katz <jkatz@postgresql.org> wrote:
>> On behalf of the RMT, I just want to make sure this keeps moving along.
>> It sounds like the next step is for Robert to verify that [3] is the
>> expected
>> behavior and then David can decide what to do from there.
>
> Yes, that's the expected behavior. If we didn't regenerate the paths
> there, we'd end up with
>
> Result
> -> Append
> -> [various paths that produce a tlist which needs to be adjusted
> later by the result node]
>
> Instead of:
>
> Append
> -> [various paths that produce an adjusted tlist]
>
> Paths of the former kind have already been generated; we regenerate
> paths here to get the latter kind as well, which end up displacing the
> old ones on cost.
>
An update from the RMT: after our meeting today, we decided that we
would drop this from the list of open items for the 11 major release.
The initial issue was already fixed and we understand that developing
the test for this will take some work and we do not thing it is needed
for the v11 release.
Thanks again for working on this!
Jonathan