[socmag]

Clocks are meaningless under load.

The higher frequency the transactions the more you get into quantum physics.

In reality, nobody cares if T-Mobile debited your account 0.01ms before WalMart.

[edit] what is important is isolation and consistency of the transactons.

[dang]

We detached this subthread from https://news.ycombinator.com/item?id=14308521 and marked it off-topic.

[johnhenry]

Actually, WalMNart cares and so does T-mobile. You probably care too if you stop and think for a bit...

The concern here isn't just order of transactions, but also synchronization. For instance, WalMart might charge you twice for a transaction if it appears to have happened at different times when it arrives in different data centers.

Also, the comment "The higher frequency the transactions the more you get into quantum physics." isn't relevant here. This is more in the realm of relativity than quantum physics. Even so, we aren't currently at a point where we need to worry about transactions happening at relativistic speeds.

[socmag]

No I disagree since you left out atomicity from your argument.

WalMart cannot commit if someone else committed previously, they have to try again.

Atomicity is precisely what it is. There is no fuzziness there, you either do it or you don't.

The problem with current database designs is the idea of BeginTransaction, that function is the core of the problem.

"Transactions" in the real world are NOT completed until everyone agrees.

Consider you yourself enter into a transaction with your landlord, you BeginTransaction..

However during the negotiation you choose to disagree and back away from the deal.

That transaction, even though it took three months to decide was rejected (by either party).

The only "transaction" is the committed transaction.

[socmag]

Instead of just downvoting, how about refuting my claim?

I'm seriously curious what is the disagreement. These guys already established atomic clocks are unnecessary. Very interested in which use cases require them.

[theptip]

Read and learn: https://research.google.com/archive/spanner.html

Serializability is all about ensuring a single consistent ordering of events. Lots of algorithmic shortcuts you can take if all your nodes' clocks are precisely in sync.

[nocman]

Am I wrong in remembering that the HN guidelines used to say that you should not downvote someone's comment simply because you disagreed with it?

I went looking, and I don't see that in the current guidelines. I could be wrong about it being there before, but I was almost certain that it was at one point.

Seems like it used to say that you should only downvote comments that you think don't contribute anything of value to the conversation.

Just curious, because it seems to me that for quite a while now there have been a lot of comments that appear to get downvoted just because people don't agree with what the person said (and often there are no responses to counter, the person just gets downvoted).