heed VS tikv

At Meilisearch we are currently trying to add a better error handling in heed v0.20, our LMDB key-value store wrapper. Unfortunately, when there are a lot of generics it can become harder to play with…

There are issues and pull requests but I advise you to look at the milli folder in the Meilisearch repository, it’s where all the logic is done. We extensively use RoaringBitmaps, heed the LMDB wrapper and grenad when indexing.

I’ll continue to introduce new features and new safety guards until v0.20.0. Can you tell me more about your project? Or is it private?

LMDB support multiple readers and one writer at the same time. It is ensured by the library. Note that LMDB is a key-value store. You can use the heed library which is the most maintained Rust wrapper.

Note that heed is ensuring that you are not trying to use transactions, databases and environments in the right way. I have added much more work in that regard in the important update that I am working on too!

I am currently working on exposing the new LMDB encryption feature from heed the safe LMDB wrapper with the help of the Cryptography community.

Have you considered heed or even sanakirja?

rkv hasn't been updated for a while. I recommend using heed - https://docs.rs/heed

For wrappers around LMBD, I'd recommend RKV or Heed https://github.com/mozilla/rkv https://github.com/Kerollmops/heed

I know that very similar functionality to this is in TiDB Serverless ( https://tidbcloud.com ). TiDB is a distributed relational database. It uses TiKV ( which is a key/value engine ) as the storage engine. You could use SQL to access your K/V records. There is ongoing work in TiKV to support S3 directly as the storage backend ( https://github.com/tikv/tikv/issues/6506 ) .

TiKV is basically a layer on top of rocksdb https://github.com/tikv/tikv/blob/956610725039835557e7516828...

> Many,many smart people…

If you look inside the code you can see the stated features are a result of underlying engine (TiKV [0] also in c and rust from pingcap). Surrealdb is standing on shoulders of giants at present, they are TiKV, FoundationDB and rocksdb. The feature set they mentioned mostly coming from TiKV at present.

[0] https://tikv.org/

Hi Diggsey, great question. We are currently focussed on functionality and stability, and then will draw our attention to performance. Coming this week we have a RocksDB storage implementation. We've only just launched our initial beta version, and we know there is a lot of improvement and work to be done (some of these performance issues we know about already and are on our Github issues list).

With regards to the consistency/isolation model, SurrealDB sits on top of a number of key-value stores. By using the distributed highly-available TiKV storage backend, https://tikv.org, (and we have a FoundationDB integration in the works), the database is designed to be highly-scalable and highly-available. The same guarantees (albeit just single-node, so no high-availability or scalability) will be available with the RocksDB implementation coming this week. By sitting on top of these key-value stores, SurrealDB ensures that all transactions are ACID compliant. We don't want to go for speed (for instance by writing to /dev/null) over anything, but want SurrealDB to be a reliable and performant backend for any application. Obviously we have a way to go to catch up with PostgreSQL (launched in 1996), but we will strive to get there!

If you are looking for a production ready distributed store written in Rust. Check out TiKV(https://github.com/tikv/tikv), which was also mentioned in the acknowledge section of the project's README.

There's also a full-featured distributed RDBMS called TiDB built on top of TiKV.