MongoDB vs. PostgreSQL vs. ScyllaDB: Tractian’s Experience

MongoDB vs. PostgreSQL vs. ScyllaDB: Tractian’s Experience(thenewstack.io)

11 points by carpintech 2 years ago | 4 comments

winrid 2 years ago |

But Scylla doesn't offer the same consistency guarantees as Mongo, right? You can shard pretty wide with Mongo and still read your own writes, while my understanding is Scylla is eventually consistent?

kinghajj 2 years ago | |

Scylla has "tunable" consistency[1][2][3], so it's possible to get consistency without too much of a performance hit, and still be resilient to some failures.

[1]: https://www.scylladb.com/glossary/eventual-consistency/

[2]: https://docs.scylladb.com/stable/cql/consistency.html

[3]: https://docs.scylladb.com/stable/cql/consistency-calculator....

PeterCorless 2 years ago | | |

On top of this, ScyllaDB also has "Lightweight Transactions" (LWT) that use Paxos to do a compare-and-set (CAS) read-before-write. This is important for strict linearizability. You can think of it really roughly as "single partition ACID."

They are also implementing a Raft infrastructure upon which they will be able to do strong consistency transactions in the future.

https://www.scylladb.com/tech-talk/the-future-of-consensus-i...

[Disclosure: I used to work at ScyllaDB]

winrid 2 years ago | | |

Nice, thanks! I haven't used it yet.