On Tue, 2006-06-06 at 12:50, Craig A. James wrote: > 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 node of the query plan could be vital information. For a query that never finishes, you can't even find out where it's getting stuck. > > That's why Simon's proposal might help in some particularly difficult situations. Hmmmmm. I wonder if it be hard to have explain analyze have a timeout per node qualifier? Something that said if it takes more than x milliseconds for a node to kill the explain analyze and list the up to the nasty node that's using all the time up? That would be extremely useful.
