We have covered a ton so far and it's been a lot of fun, but we are not done yet.
We started at the very bottom with the schema. We talked about what does your data look like? How can we represent that in MySQL and what is the most compact way that we can store that data? That gives us our good foundation.
Then we talked about what indexes are, how they work, how the B-tree works, primary keys, secondary keys, how they're linked together. We talked about that for a long time!
Now we get to talk about querying our data, actually accessing our data. We're going to use all of this knowledge that we learned before. We're going to use all of that in this section. I'm hoping, my hope is that all of those things we've learned already are going to make this section really easy. The number one rule for writing good queries is user indexes. So we already know so much about indexes that I'm hoping all of this is going to come together in the querying section.