The benchmark is incremental. It measures how fast you can insert N rows given M rows already in the database. So, the second data point means you can insert roughly 750,000 rows in 140 seconds, given 750,000 rows already in the database. The limit certainly doesn't approach zero as the number of elements approaches infinity :)
The engine isn't open source. We're considering open sourcing it in the future, but we want to understand all business implications of this decision before we proceed - it's a decision you can't easily retract. The license is a bit draconian, but this is because we've only released a developer pre-alpha. We don't want people to use the engine in production yet - it's not ready. AFAIK, the license says you can't sell RethinkDB support, not that you can't sell support for software that uses RethinkDB.
For the moment, we cannot endorse using RethinkDB in a production environment, and even then, this license is meant to be free for non-commercial. Once we get to that point, we'll be re-visiting the license anyway, before we start licensing to commercial users.
Thanks for bringing this to our attention. I'm honestly not sure what the intention was since I didn't do the license, but I'll talk to the guys here about it.
So is the X-axis mislabelled? Along the bottom it says "Number of elements being inserted" going from zero on the left to 2,000,000 on the right, but the title says "Time to insert 2,000,000 elements". Something's very wrong somewhere.
The engine isn't open source. We're considering open sourcing it in the future, but we want to understand all business implications of this decision before we proceed - it's a decision you can't easily retract. The license is a bit draconian, but this is because we've only released a developer pre-alpha. We don't want people to use the engine in production yet - it's not ready. AFAIK, the license says you can't sell RethinkDB support, not that you can't sell support for software that uses RethinkDB.