Firstly, I think it is so cool to find ☞ Kent Beck blogging about NoSQL. Unfortunately, I don’t really agree with his conclusion that the driving force behind NoSQL is energy costs.
His reasoning goes this way:
[…] if you want to understand technical change it’s more effective to follow the money.
The performance advantages of an alternative data storage paradigm (column-oriented, document-oriented, key-value, map-reduce) don’t justify the additional cost and complexity.
Eliminate the license and the cost of electricity becomes a huge percentage of the cost of a database.
What if you can avoid the hardware upgrade by shifting to an alternative database?
I am fine with this deduction, but I think there is something critical Kent omitted.
At large scale, once you got rid of licensing costs — which was possible before NoSQL by replacing commercial RDBMS with open source solutions — the very next concern is scalability and complexity costs. And we need to agree that once you are mistakenly ignoring these costs (either by mis-categorizing them as “only” performance advantages or by using wrong arguments), then the conclusion is not valid anymore.
So, energy savings are extremely important in the economy of scaling, but only together with the other factors covered so well in the first part of Emil Eifrem’s presentation (note: I strongly encourage you to check it out).