Wide Trees and the Disk
Last timeAsking for Everything Between
On a disk, reading one item and reading a thousand cost the same. That single fact reshapes the tree into something wide and shallow, which is the index inside every database.
Every cost so far has been counted in comparisons. Storage does not charge for
comparisons, and once the right thing is counted the structure has to change
shape.
The lesson stops here
1 more paragraph to go
You have read the opening. The rest of the argument, the problems that check whether it landed, and the lines worth keeping at the end all come with a plan.
The first lesson of every course in the library reads the whole way through, free, so you can see exactly what the rest of them are.
See the planThe contentsThis is the reading half
Starting the course gives you your own copy of it. Every idea on every page has problems standing under it, marked with a reason rather than a tick, and any sentence you do not believe can be opened and argued with. None of that can happen on a page nobody owns.
The contents