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Comment by justinclift | Hacker News Reader

> which kills SQL row locks.

What's it like compared to MVCC?

Depending on contention and RTT, as a specialized OLTP DBMS, TB can do roughly 1000-2000x more performance than a single node OLGP DBMS (cf. the live demo in the talk above)… but also with strict serializability. You don’t need to sacrifice correctness or real-time resolution, and that’s important. For example, if you need to do real-time balance checks.

Hmmm, I guess it sounds weird to me to be talking "RTT" (round trip time) when the example is "a single node".

I'll watch your talk properly at some point and see if it makes sense to me after that. :)

Node count doesn't matter. You could use an embedded database and encounter the same problem. There is some time T between when you acquire a lock and release it. Depending on the amount of contention in your system, this will have some affect on total throughput (i.e. Amdahl's law).

How familiar are you with MVCC?

https://www.postgresql.org/docs/current/mvcc-intro.html

Asking because needing a lock for changing a row isn't the only approach that can be taken.

Almost all commercial MVCC implementations (including Postgres) use row locks. Very few use OCC even though it's arguably a more natural fit for MVCC. Pessimistic locking is simply more robust over varied workloads.

TB seems really awesome, but is there non-DebitCredit use cases where it can be applied effectively? I like trying to find off-label uses for cool technology

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