Re: Foreign join pushdown vs EvalPlanQual

On 2015/10/01 15:38, Kyotaro HORIGUCHI wrote:
>> I expect FDW driver needs to handle EPQ recheck in the case below:
>> * ForeignScan on base relation and it uses late row locking.

> I think this is indisputable.

I think so.  But I think this case would probably be handled by the
existing RefetchForeignRow routine as I said upthread.

>> * ForeignScan on join relation, even if early locking.

> This could be unnecessary if the "foreign join" scan node can
> have its own rowmark of ROW_MARK_COPY.

That's an idea, but I'd vote for preserving the applicability of late
row locking to the foreign join case, allowing component foreign tables
involved in a foreign join to have different rowmark methods other than
ROW_MARK_COPY.

Best regards,
Etsuro Fujita