Named KV stores / trees for sled

[joepio]

In sled, a single filesystem path can correspond to multiple KV stores. They are called Trees in sled. I think in OpenDAL they are names, and in S3 they are buckets. Maybe I'm confusing concepts here, but you probably get the point.

Is there a way OpenDAL supports having multiple KV namespaces, without having to open multiple filesystem paths?

[Xuanwo]

without having to open multiple filesystem paths

That makes sense!

I'm not familiar with sled. I have some questions: Embedded databases like sled and rocksdb will have locks to prevent them from being opened concurrently. Is it safe to open different trees that are in the same directory?

Is there a way OpenDAL supports having multiple KV namespaces

If the answer to the previous question is yes, then we can have Operators for multiple trees simultaneously.

[joepio]

Is it safe to open different trees that are in the same directory?

Yes, as far as I understand. I've used this feature quite a bunch.

Thanks!

[Xuanwo]

Cool, let's do this. I think we can add a new config called tree for SledBuilder and use default if it's empty.

Tasks

• Add tree in SledBuilder
• Add integration tests to cover sled with specifed tree name.

[Xuanwo]

Taken by @oowl. Perhaps @joepio could also provide a review?

[joepio]

You are AWESOME, thank you!

[joepio]

I'll look a little later, tomorrow

[Xuanwo]

Implemented by #2516!