Re: Some queries starting to hang

Tom Lane wrote:
>>The idea I just had was: why do we need EXPLAIN ANALYZE to run to
>>completion? In severe cases like this thread, we might be able to
>>discover the root cause by a *partial* execution of the plan, as long as
>>it was properly instrumented. That way, the OP might have been able to
>>discover the root cause himself...
>
>
> I don't think that helps, as it just replaces one uncertainty by
> another: how far did the EXPLAIN really get towards completion of the
> plan?  You still don't have any hard data.

But at least you have some data, which is better than no data.  Even knowing that the plan got stuck on a particular
nodeof the query plan could be vital information.  For a query that never finishes, you can't even find out where it's
gettingstuck. 

That's why Simon's proposal might help in some particularly difficult situations.

Regards,
Craig