Histograms are Evil like Chocolate is Evil
Are you using Histograms? Yes, of course you are – even if you didn’t know it. Did you want to use them? Are they helping you get to the optimal optimization plan, or making life harder for the optimizer? I will explain the benefits and threats associated with histograms, how the new 12.2 histogram types make them more acceptable, where they are still a threat and how I usually handle them for greatest benefit in large systems.