H2 Database Engine vs. Titan Distributed Graph Database

This really depends on the use case. For an in-memory replacement database for running unit test cases with, H2 Database Engine is an excellent option. However, if you are looking for a general purpose database for your production systems, then H2 Database Engine is not suited for this purpose.

Incentivized

Titan is definitely a good choice, but it has its learning curve. The documentation may lack in places, and you might have to muster answers from different sources and technologies. But at its core, it does the job of storing and querying graph databases really well. Remember that titan itself is not the whole component, but utilizes other technologies like cassandra, gremlin, tinkerpop, etc to do many other things, and each of them has a learning curve. I would recommend titan for a team, but not for a single person. For single developer, go with Neo4j.

Incentivized

• Can run as an in-memory database.
• Simple and quick to get started with, and is light weight (only 2MB).
• SQL compliant so it compatible with most relational databases.

Incentivized

• Titan is really good for abstraction of underlying infrastructure. You can choose between different storage engine of your choice.
• Open source, backed by community, and free.
• Supports tinkerpop stack which is backed by apache.
• Uses gremlin for query language making the whole query structure standardized and open for extension if another graph database comes along in future.

Incentivized

• There's a warning in official FAQ "Is it Reliable?"-section which makes it seem like H2 is not yet a mature product.
• If raw SQL queries are used there maybe be differences between MySQL & H2. ORM library should be used.
• Support seems to be community-based only.

Incentivized

• The community is lacking deep documentation. I had to spend many nights trying to figure many things on my own. As graph databases will grow popular, I am sure this will be improved.
• Not enough community support. Even in SO you might not find many questions. Though there are some users in SO who quickly answer graph database questions. Need more support.
• Would love an official docker image.

Incentivized

Both MySQL & H2 [Database Engine] are relational databases & use same query language. Application features can be implemented with both but if it's expected that the application will be used by large user base or is complex MySQL is better. Cloud providers provide scaling support for MySQL and also it's more battle-tested. H2 is good when it's a small application as H2 is easier & quicker to set up.

Incentivized

To be honest, titan is not as popular as Neo4j, though they do the same thing. In my personal opinion, titan has lot of potential, but Neo4j is easier to use. If the organization is big enough, it might choose titan because of its open source nature, and high scalability, but Neo4j comes with a lot of enterprise and community support, better query, better documentation, better instructions, and is also backed by leading tech companies. But titan is very strong when you consider standards. Titan follows gremlin and tinkerpop, both of which will be huge in future as more graph database vendors join the market. If things go really well, maybe Neo4j might have to support gremlin as well.

Incentivized

• Doesn't take time from developers, once it's configs are set up for testing it works in everyone's development environments
• Easy to integrate in application, no need to setup separate database software, no maintenance
• No need to deal with infrastructure related issues/costs - database runs in same machine as the application that uses it.

Incentivized

• Steep learning curve. Your engineers would have to spend lots of time learning different components before they feel comfortable.
• Have to plan ahead. Maybe this is the nature of graph databases, but I found it difficult to change my schemas after I had data in production.
• It is free, so time is the only resource you have to put in titan.

Incentivized