Transactions

Transaction Types

ArangoDB offers different types of transactions:

• AQL queries (with exceptions)
• Stream Transactions
• JavaScript Transactions

Stream Transactions

Stream Transactions allow you to perform multi-document transactions with individual begin and commit / abort commands. They work similar to the BEGIN, COMMIT, and ROLLBACK operations in relational database systems.

The client is responsible for making sure that transactions are committed or aborted when they are no longer needed, to avoid taking up resources.

JavaScript Transactions

JavaScript Transactions allow you to send the server a dedicated piece of JavaScript code (i.e. a function), which will be executed transactionally.

At the end of the function, the transaction is automatically committed, and all changes done by the transaction will be persisted. No interaction is required by the client beyond the initial request.

Transactional Properties

Transactions in ArangoDB are atomic, consistent, isolated, and durable (ACID).

These ACID properties provide the following guarantees:

• The atomicity principle makes transactions either complete in their entirety or have no effect at all.
• The consistency principle ensures that no constraints or other invariants will be violated during or after any transaction. A transaction will never corrupt the database.
• The isolation property will hide the modifications of a transaction from other transactions until the transaction commits.
• Finally, the durability proposition makes sure that operations from transactions that have committed will be made persistent. The amount of transaction durability is configurable in ArangoDB, as is the durability on collection level.

The descriptions in this section only provide a general overview. The actual transactional guarantees depend on the deployment mode and usage pattern.

Also see:

• Operation Atomicity for more details on atomicity guarantees
• Transactional Isolation for more details on isolation guarantees in the single server and OneShard database case
• Cluster Transaction Limitations for more details on the transactional behavior of multi-document transactions in cluster deployments