On 2016/10/07 10:26, Amit Langote wrote:
> On 2016/10/06 21:55, Etsuro Fujita wrote:
>> On 2016/10/06 20:17, Amit Langote wrote:
>>> On 2016/10/05 20:45, Etsuro Fujita wrote:
>> I noticed that we were wrong. Your patch was modified so that
>> dependencies on FDW-related objects would be extracted from a given plan
>> in create_foreignscan_plan (by Ashutosh) and then in
>> set_foreignscan_references by me, but that wouldn't work well for INSERT
>> cases. To fix that, I'd like to propose that we collect the dependencies
>> from the given rte in add_rte_to_flat_rtable, instead.
> I see. So, doing it from set_foreignscan_references() fails to capture
> plan dependencies in case of INSERT because it won't be invoked at all
> unlike the UPDATE/DELETE case.
Right.
>>>> If some writable FDW consulted foreign table/server/FDW options in
>>>> AddForeignUpdateTarget, which adds the extra junk columns for
>>>> UPDATE/DELETE to the targetList of the given query tree, the rewritten
>>>> query tree would also need to be invalidated. But I don't think such an
>>>> FDW really exists because that routine in a practical FDW wouldn't change
>>>> such columns depending on those options.
>> I had second thoughts about that; since the possibility wouldn't be zero,
>> I added to extract_query_dependencies_walker the same code I added to
>> add_rte_to_flat_rtable.
> And here, since AddForeignUpdateTargets() could possibly utilize foreign
> options which would cause *query tree* dependencies. It's possible that
> add_rte_to_flat_rtable may not be called before an option change, causing
> invalidation of any cached objects created based on the changed options.
> So, must record dependencies from extract_query_dependencies as well.
Right.
> I think this (v4) patch is in the best shape so far.
Thanks for the review!
Best regards,
Etsuro Fujita
