Database internals and transactional behavior

Atomicity — If a part of a transaction fails, the database state is left unchanged.

Consistency — Every transaction leaves the database in a consistent state.

Isolation — During a transaction, modified data cannot be accessed by other operations.

Durability — The DBMS can always recover the results of a committed transaction.

All database operations that access the graph, indexes, or schema must be performed in a transaction.

The default isolation level is read-committed isolation level.

Write locks are acquired automatically at the node and relationship levels. However, you can also manually acquire write locks if you want to achieve a higher level of isolation — serializable isolation level.

Data retrieved by traversals is not protected from modification by other transactions.

Non-repeatable reads may occur (i.e., only write locks are acquired and held until the end of the transaction).

Deadlock detection is built into the core transaction management.

Transaction management

Locks and deadlocks

Transaction logging

Checkpointing and log pruning

Store formats