On Mon, Aug 8, 2016 at 4:35 PM, Craig Boucher <cr...@wesvic.com> wrote:
> Thanks David. I’ve thought about the hierarchy you mentioned but the > hierarchy can change and I need to capture it as it was when the data was > generated. > > > > I should have pointed out in my last response that I was wondering if the > performance of the pk index on work_session would be better if my primary > key was (customer_id, work_session_id) or if (work_session_id, > customer_id) will be fine. Customer_id will be repeated quite a bit in > the table but work_session_id should be unique across the whole table. > > > I answered that in the original response...for PKs to operate most efficiently the most selective attribute should come first. David J.