Re: [HACKERS] EvalPlanQual behaves oddly for FDW queries involvingsystem columns

Hi,

On 2015-05-12 14:24:34 -0400, Tom Lane wrote:
> I did a very basic update of your postgres_fdw patch to test this with,
> and attach that so that you don't have to repeat the effort.  I'm not sure
> whether we want to try to convert that into something committable.  I'm
> afraid that the extra round trips involved in doing row locking this way
> will be so expensive that no one really wants it for postgres_fdw.  It's
> more credible that FDWs operating against local storage would have use
> for it.

Fujita-san, do you know of any FDWs that use this? I'm currently
converting the EPQ machinery to slots, and in course of that I (with
Horiguchi-san's help), converted RefetchForeignRow to return a slot. But
there's currently no in-core user of this facility...  I guess I can
rebase the preliminary postgres_fdw patch here, but it bitrotted
significantly. I also feel like there should be some test coverage for
an API in a nontrivial part of the code...

Greetings,

Andres Freund