I grew up in a college town, and one Halloween our doorbell rang and we opened the door expecting to see trickortreaters-- but what was in front of our open door--was another door! Like, a full-on wooden door, that had a sign that said "Please knock." So we did, and the door swung open to reveal a bunch of college dudes dressed as really old grandmothers, curlers in their hair, etc, who proceeded to coo over our "costumes" and tell us we were "such cute trick or treaters!" One even pinched my cheek. Then THEY gave US candy, closed their door, picked it up and walked to the next house.
It was amazing.
[O]ur conventions for naming things should take into consideration the limitations of the human brain. The length of a variable's name should be proportional to the distance between its definition and its use, and inversely proportional to its frequency of use.
Global config setting that gets specified once and used in 4 places throughout the program? 10-20 characters is probably appropriate. Might wanna go with UPPER_SNAKE_CASE to make it stand out a bit more, even.
Iterator variable that you define in a 3-line for loop and then never see again outside of it? Call it "i".
Another way to look at this: The first time you meet someone, you learn their full name. When discussing them with someone else who knows them, you use just a single name. If they're standing right there, you don't bother using their name, but just make eye contact, and maybe a "Hey". Should be the same way with variables.
Brave new non-relational world:
For this feature, the fully denormalized Cassandra dataset weighs in at 3 terabytes and 76 billion columns.