[nuphonenuacc]

What is that first paragraph? "This implementation proves the CAP theorem as wrong"? Doesn't tell me what your drawbacks are. This is mongodb all over again. Will only ever consider if the customer really wants it. (My guess performance)

(Also, bold move to write a db without fully being able to manage memory).

[travem]

I do want to clarify a few points, on the project page it does provide the following information:

> Distributed Transactions: TiDB uses a two-phase commit protocol to ensure ACID compliance, providing strong consistency. Transactions span multiple nodes, and TiDB's distributed nature ensures data correctness even in the presence of network partitions or node failures.

> High Availability: Built-in Raft consensus protocol ensures reliability and automated failover. Data is stored in multiple replicas, and transactions are committed only after writing to the majority of replicas, guaranteeing strong consistency and availability, even if some replicas fail. Geographic placement of replicas can be configured for different disaster tolerance levels.

See https://github.com/pingcap/tidb?tab=readme-ov-file#key-featu...

Correctness has been a focus for a long time for TiDB, including working on passing Jepsen Tests back in 2019, see https://www.pingcap.com/blog/tidb-passes-jepsen-test-for-sna... and https://jepsen.io/analyses/tidb-2.1.7

Disclosure: Employee of PingCAP the company behind TiDB

[fipar]

I can't find that first paragraph, and it seems that readme file was last modified 3 months ago, though you're using quotes, so perhaps you are paraphrasing?

The first paragraph I find under Key Features is:

Distributed Transactions: TiDB uses a two-phase commit protocol to ensure ACID compliance, providing strong consistency. Transactions span multiple nodes, and TiDB's distributed nature ensures data correctness even in the presence of network partitions or node failures.

It claims to ensure correctness in the presence of partitions, not availability, so I don't think that's a claim that CAP is wrong? I would expect it to be unavailable if it can't provide a consistent response.

I don't know about memory management. It seems go may not be used for the storage layer, but in any case, it wouldn't be the first attempt at a DB on a garbage collected runtime. I can think of at least Cassandra on the jvm and CockroachDB also on Go. I do prefer that DBs do their own memory management (as well as storage) but this is not as unique as it used to be though.

[std_reply]

Go is used for the SQL layer, it’s a modern optimizer that can do distributed joins etc. ie. Issue parallel reads to the storage nodes.

Additionally, it can push down the DAG to the TiKV storage nodes, written in Rust, to reduce movement of data and work closer to the physical data.