Occasionally, I receive requests to explain stuff I talk about in my blog posts on a level accessible to beginners. Unfortunately, it’s not always possible to do so. You start to explain one little thing, and then you realize that in order to understand that thing, one would to understand a dozen other little things, and before you know it, instead of writing a short blog post you find yourself writing something of the size of Encyclopedia Britannica. I decided to try to go in a different direction. I’ve accumulated some beginner-to-intermediate-level material that hopefully should make certain topics in database performance optimization clearer. I will be posting them in form of short “lessons”. I don’t have how many such lessons will be in total — I guess this depends a lot on the feedback that I’ll be receiving. My plan is to start with statement-level optimization topics, and then, if this goes well, to move on to instance-level stuff. I will try to: 1) provide a high-level overview without getting caught up into details 2) present a holistic view of Oracle database performance rather than asystematic assembly of performance-related topics 3) “derive” facts from higher principles rather than simply state them 4) use analogies to make basic performance concepts more intuitive 5) be as quantitative and specific as possible 6) heavily use demos. Hope you’ll find it useful.