Re: Improper usage of MemoryContext in nodeSubplan.c for buildSubPlanHash() function. This maybe causes allocate memory failed.

I wrote:
> "Tao Ma" <feng_eden@163.com> writes:
>> This is a potential memory error in nodeSubplan.c or execGrouping.c
>> Using select '1'::TEXT IN ((SELECT '1'::NAME) UNION ALL SELECT '1'::NAME);
>> to reproduce this bug.
>> ...
>> To fix this problem, we can use another memory context to passin 
>> BuildTupleHashTable() as the hashtable's tempcxt, or use other memory 
>> context as hash table's tempcxt or other ways.

> Yeah, I think you're right --- we can't get away with reusing the
> innerecontext's per-tuple context for the hashtable temp contexts.
> The best solution is probably to make an additional context that
> does nothing but act as the hashtable temp context.

I've committed a fix along those lines.  Thanks for the report!
        regards, tom lane