On 13/10/2020 19:09, Heikki Linnakangas wrote:
> One little idea I had:
>
> I think all FDWs that support direct modify will have to carry the
> resultRelaton index or the ResultRelInfo pointer from BeginDirectModify
> to IterateDirectModify in the FDW's private struct. It's not
> complicated, but should we make life easier for FDWs by storing the
> ResultRelInfo pointer in the ForeignScanState struct in the core code?
> The doc now says:
>
>> The data that was actually inserted, updated or deleted must be
>> stored in the ri_projectReturning->pi_exprContext->ecxt_scantuple of
>> the target foreign table's ResultRelInfo obtained using the
>> information passed to BeginDirectModify. Return NULL if no more rows
>> are available.
>
> That "ResultRelInfo obtained using the information passed to
> BeginDirectModify" part is a pretty vague. We could expand it, but if we
> stored the ResultRelInfo in the ForeignScanState, we could explain it
> succinctly.
I tried that approach, see attached. Yeah, this feels better to me.
- Heikki