Transactions

Any query that updates the graph will run in a transaction. An updating query will always either fully succeed, or not succeed at all.

Cypher® will either create a new transaction or run inside an existing one:

  • If no transaction exists in the running context Cypher will create one and commit it once the query finishes.

  • In case there already exists a transaction in the running context, the query will run inside it, and nothing will be persisted to disk until that transaction is successfully committed.

This can be used to have multiple queries be committed as a single transaction:

  1. Open a transaction,

  2. Run multiple updating Cypher queries.

  3. Commit all of them in one go.

Note that a query will hold the changes in memory until the whole query has finished executing. A large query will consequently use large amounts of memory. For memory configuration in Neo4j, see the Neo4j Operations Manual.

For using transactions with a Neo4j driver, see the Neo4j Driver manual. For using transactions over the HTTP API, see the HTTP API documentation.

When writing procedures or using Neo4j embedded, remember that all iterators returned from an execution result should be either fully exhausted or closed. This ensures that the resources bound to them are properly released.