Re: Another oddity in handling of WCO constraints in postgres_fdw

On Wed, Oct 4, 2017 at 6:40 AM, Ashutosh Bapat
<ashutosh(dot)bapat(at)enterprisedb(dot)com> wrote:
> Just like the local constraints on a foreign table are not ensured on
> remote table (unless user takes steps to make that sure), WCO defined
> locally need not be (and probably can not be) ensured remotely. We can
> check whether a row being sent from the local server to the foreign
> server obeys WCO, but what foreign server does to that row is beyond
> local server's scope.

But I think right now we're not checking the row being sent from the
local server, either. The WCO that is being ignored isn't a
constraint on the foreign table; it's a constraint on a view which
happens to reference the foreign table. It seems quite odd for the
"assume constraints are valid" property of the foreign table to
propagate back up into the view that references it.

--
Robert Haas
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