> Memory, and CPU, and even storage eventually, those would be the main practical examples of where having a key that's composed of something very small saves you space and thus, time.
> Say we want to use a bigint key vs a VARCHAR(30)? depending on your big key you might be talking about terabytes of additional data, just to store a key (1t rows @ bigint = 8TB, 1T rows at 30 chars? 30TB...). The data also is going to constantly shuffle (random inserts).
>> Joins, lookups, indexes
I don't see how what you brought up has anything to do with these.
But the main point is being missed here because of a physical vs logical conflation anyhow.
> Say we want to use a bigint key vs a VARCHAR(30)? depending on your big key you might be talking about terabytes of additional data, just to store a key (1t rows @ bigint = 8TB, 1T rows at 30 chars? 30TB...). The data also is going to constantly shuffle (random inserts).
>> Joins, lookups, indexes
I don't see how what you brought up has anything to do with these.
But the main point is being missed here because of a physical vs logical conflation anyhow.