Re: postgres_fdw : altering foreign table not invalidating prepare statement execution plan.

On Fri, Sep 30, 2016 at 1:09 AM, Ashutosh Bapat
<ashutosh(dot)bapat(at)enterprisedb(dot)com> wrote:
>>
>>> The attached patch adds the
>>> dependencies from create_foreignscan_plan() which is called for any
>>> foreign access. I have also added testcases to test the functionality.
>>> Let me know your comments on the patch.
>>
>>
>> Hmm. I'm not sure that that's a good idea.
>>
>> I was thinking the changes to setrefs.c proposed by Amit to collect that
>> dependencies would be probably OK, but I wasn't sure that it's a good idea
>> that he used PlanCacheFuncCallback as the syscache inval callback function
>> for the foreign object caches because it invalidates not only generic plans
>> but query trees, as you mentioned downthread. So, I was thinking to modify
>> his patch so that we add a new syscache inval callback function for the
>> caches that is much like PlanCacheFuncCallback but only invalidates generic
>> plans.
>
> PlanCacheFuncCallback() invalidates the query tree only when
> invalItems are added to the plan source. The patch adds the
> dependencies in root->glob->invalItems, which standard_planner()
> copies into PlannedStmt::invalItems. This is then copied into the
> gplan->stmt_list. Thus PlanCacheFuncCallback never invalidates the
> query tree. I have verified this under the debugger. Am I missing
> something?

Moved to next CF. Feel free to continue the work on this item.
--
Michael