What I've found is that last week, my whole process took 4hrs (which is great, for when I ran the same code within a SYBASE environment it took 17hrs!), but now I'm finding it takes 17hrs just for a single command! Nothing has changed in the code - it's as if the optimizer is having a bad day!
So to try and discern what's going on within the optimizer, I'm trying different things. If a change doesn't 'look' to be working, I cancel the query and try something else. Because the PC seems to slow right down when I cancel - it all gets very frustrating!
Is this useful?