ArangoDB is a multi-model mostly-memory database with a flexible data model for documents and graphs. It allows users to specify either multi-collections transactions for ACID properties or standard single-document transactions for performance boosting. The whole software is under the Apache 2.0 license.
ArangoDB allows users to define their own User Defined Functions (UDFs). Users can also use the Foxx microservice framework to build their own logic into a microservice inside the database and able to access data it needs. This can achieve the same functionalities of stored procedures.
Key/Value Document / XML Graph
In ArangoDB, a document collection always has a primary key _key
. Therefore, without specifying any secondary index, it is just like a key-value store. Generally, there can be multiple attributes and multiple secondary indexes, then it is like a common document store. By default, the sharding key is the same as the primary key _key
. Therefore it can achieve good linear scalability. Besides key-value store and document store, ArangoDB can also support graph store with comprehensive functionalities.
Two-Phase Locking (Deadlock Detection)
The user need to specify which collections a transaction needs to read/write. ArangoDB will first collect all the locks in alphabetical order of the collection names at the beginning of each transaction, and release the locks in reverse order after the transaction finishes. In case there is a deadlock, ArangoDB will automatically abort one of the transactions, roll back the changes, and throw error 29 (deadlock detected
) to the client.
https://github.com/arangodb/arangodb
ArangoDB GmbH
2011
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