[w3clan]

I had the very same feeling, dgraph is older and has a larger community plus additional features like:

- geospatial features

- good speed as it is based on badgerdb key value database and ristello cache library.

- http library and other features

One of the advantage I saw in nebula graph is security role based access which is not available in dgraph until today.

I am very curious about benchmark between nebula graph and dgraph.

Also what is storage system used in nebula graph.

[ayorosmage]

ACL is an enterprise dgraph feature: https://dgraph.io/support

[jamie-vesoft]

geospatial is also available in Nebula Graph.:)

As to the storage system, Nebula Graph is based on multi-group raft and RocksDB.

[w3clan]

Can you add support for module based storage system like, if someone wants to use badgerdb or leveldb or any other storage system instead of rocksdb

[jamie-vesoft]

Yes, Nebula Graph supports multiple backend storages by design. So theoretically you are able to use whatever storage you want for whichever graph space in Nebula Graph.

You may take a look at this article about the design of our storage engine: https://github.com/vesoft-inc/nebula/blob/master/docs/manual...

In 2020 we will be working on more plugins. You may stay tuned if that interests you. :)

[jhoechtl]

Geospatial is on the TODO list

[jamie-vesoft]

Geospatial support has already been merged to the code base. :)

[w3clan]

Dgraph has another disadvantage of data redundancy, where data associated with multiple index are stored multiple times for speed.

Does nebula also store data multiple time for multiple index?

[jamie-vesoft]

Thanks for asking! Sorry I missed this question earlier.

Nebula doesn't store data multiple times for index.

And here's how the indexing works in Nebula Graph:

You are allowed to create multiple indexes for one tag or edge type in Nebula Graph. For example, if a vertex has 5 properties attached to it, then you can create one index for each if it's necessary for you. Both indexes and the raw data are stored in the same partition with their own data structure for quick query statement scanning. Whenever there are "where" clause/syntax in the queries, the index optimizer decides which index file should be traversed.

[campoy]

Hi there, out of curiosity what do you mean the data is stored multiple times for speed?

We (I work at Dgraph) have data redundancy when you have multiple replicas for a given group - but that's an optional feature.

Thanks!