Earlier quoted context omitted.
Trader Joe's is excellent about this. I'm not sure if it's explicit policy but every single time I've asked an employee where something is they dropped what they were doing, walked over to the exact spot and literally handed me the item I was looking for. I guess that's only possible in a small store though.
This is absolutely standard in the UK in all the supermarkets I'm aware of. If a member of staff doesn't know where the item is, they'll go and find someone who does.
Mind you, if they didn't insist on moving everything to increase customer circulation ...