All fifty US states and Washington, D.C., require children from birth through age five to be vaccinated against certain communicable diseases as a condition of attending child care settings such as ...

Every two years, the world comes together in celebration of the Olympic Games. Established in Greece, the Olympics have been around for thousands of years. While they've evolved over time, one thing ...

A nested set is a smart way to implement an ordered tree that allows for fast, non-recursive queries. For example, you can fetch all descendants of a node in a single query, no matter how deep the ...