ArangoDB vs MariaDB

You can model your data as documents or as a graph - no data model lock-in. You can even combine both models and use them in a single AQL query.

Unlike many NoSQL databases, ArangoDB does support joins in AQL queries.

You can extend ArangoDB using JavaScript that runs directly on the Server (Google V8). You can build data-centric microservices that aggregate, validate, transform or enrich data (It's up to you, plain JavaScript) and provide those via a custom API route.

You can use ACID Transactions for short and small data retrieval and/or modification operations in ArangoDB.

ArangoDB has a very good Java Driver for synchronous and asynchronous. In addition the team there is working on a Spring Data integration.

All development decisions for MariaDB can be reviewed and debated on a public mailing list or in the public bug tracker. Contributing to MariaDB is easy and the patch flow is fully transparent and public. But it's not all about the code contribution either - MariaDB also has very active documentation efforts and other related things that help developers in their day-to-day database administration.

e.g. GIS since 5.3

MariaDB has dynamic column support which allows for some NoSQL type functionality. So one database interface can provide both SQL and NoSQL for different software development needs.