Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> Can anyone explain this failure? It still exists in CVS.
>> update t1 set f2=count(*) from t2 where t1.f1=2 and t2.f1=t1.f1 ;
>> ERROR: ExecutePlan: (junk) `ctid' is NULL!
As I recall, discussion about fixing that problem trailed off because
no one could explain what an aggregate means in UPDATE. My thought
is we should probably forbid the construct entirely (SQL does).
See previous discussion around 7/7/00.
regards, tom lane