1. Shortlist (and in no order): Neo4j, AWS Neptune, Datastax Graph, TigerGraph, Azure CosmosDB, and JanusGraph (Titan fork) are the ones we see the most in practice, and not in production but rumor-mill, Dgraph, RedisGraph, & ArangoDB. The three-and-four-letter types seem to roll their own, for better or worse. There are also some super cool ones that don't get visibility outside of the HPC+DoD world, like Stinger & Gunrock. Interestingly, the reality is a ton of our graph users aren't even on graph DBs (think Splunk/ELK/SQL), and for data scientists, just do ephemeral Pandas/Spark. As someone from the early days of the end-to-end GPU computing movement, we're incorporating cuGraph (part of nvidia rapids.ai) into our middle tier, so you get to transparently benefit from it while looking at data in any of the above.
2. I now slice graph DB's more in terms of OLTP (neo4j, janus, neptune, maybe tiger) vs OLAP (spark graphx, cugraph) vs batch (janus, tiger) vs friendly BI/data science (neo4j) vs friendly app dev / multi-modal add-on (CosmosDB, Neo4j, Arango, Redis). Curious to see how this goes -- given the number of contributors, I'm guessing it's doing well in at least one of these. +1 to hearing reports from others!
I.e. what’s the graph DB that best fits the use-case equivalent to “having your data in an RDBMS and then running an indexer agent to feed ElasticSearch for searching”?
* Primary DB: type / scale, and how fresh do the extracts need to be (daily, last minute?)
* Are queries more search-centric ("entities 4 hops out") or analytics ("personalized pagerank")?
* Graph size: 10M relations, or 10B? Document heavy, or mostly ints & short strings?
* Is the client consuming the graph via a graph UI, or API-only?
* Licensing and $ cost restrictions?
* Push-button or inhouse-developer-managed?
The result of (valid) engineering trade-offs by graph db dev teams means that, currently, adding a graph db as a second system can be tricky. The above represent potential mismatches between source db / graph stack / workload and team burden. Feels like this needs a flow chart!
Happy to answer based on the above, and you can see why I'm curious which areas Nebula will help straddle :)