I am going to write a little bit about the sessions I went to at SQL Saturday, and I am going to do them in reverse order. So the last session I went to was Ayman El-Ghazali’s beginner session on SQL Server internals.
Without a doubt, the highlight of the session was when Ayman compared spinning magnetic spindles to flogging a donkey. If you watch the video below, when you delete a folder, it is indeed like flogging a donkey. It’s an expensive and ungraceful operation that helps you start to see why SSDs are such an improvement.
This leads us to an even funnier YouTube video (circa 2008) Ayman mentioned showing another big downside to spinning magnetic storage. If you shout at it, it slows down:
One of Ayman’s storage metaphors really hit home for me, because in the DC metro area we sometimes have to pay a nickel for shopping bags. While this a tiny amount of money, it makes us pay much closer to attention to which stores have quality bags. For the same nickel, we can get a strong, large bag at the hardware store or a tiny, thin bag from the supermarket. At the hardware store we get to carry more stuff but we’ve spent the same nickel. Ayman likened this to disk allocation units (AU). If you set your AU to 64k, you can get a full extent read for the same “nickel” if you change the default of 4k.
I really liked Ayman’s diagrams and found that was something to pick up even in a beginner session at the end of the day and I’m glad I stuck around til the end to see it. I only wish the cookies had been real.
My only suggestion to the presenter would be to buy a clicker because running back to the laptop to advance the slides can really interrupt the flow. I had a clicker at a previous job and found it really helped when giving presentations.