3.4.5.4. Transaction Parameters
Transaction Timeout

You can set a timeout in seconds for created transaction. When the timeout is exceeded, the transaction is interrupted and rolled back. Transaction timeout effectively limits the maximum duration of a database request.

When transactions are managed programmatically, the timeout is specified by passing TransactionParams object to the Persistence.createTransaction() method. For example:

Transaction tx = persistence.createTransaction(new TransactionParams().setTimeout(2));

In case of declarative transactions management, use the timeout parameter of the @Transactional annotation:

@Transactional(timeout = 2)
public void someServiceMethod() {
...

The default timeout can be defined using the cuba.defaultQueryTimeoutSec application property.

Read-only Transactions

A transaction can be marked as read-only if it is intended only for reading data from the database. For example, all load methods of DataManager use read-only transactions by default. Read-only transactions yield better performance because the platform does not execute code that handles possible entity modifications. BeforeCommit transaction listeners are not invoked as well.

If the persistence context of a read-only transaction contains modified entities, IllegalStateException will be thrown on attempt to commit the transaction. It means that you should mark a transaction as read-only only when you are sure that it doesn’t modify any entity.

When transactions are managed programmatically, the read-only sign is specified by passing TransactionParams object to the Persistence.createTransaction() method. For example:

Transaction tx = persistence.createTransaction(new TransactionParams().setReadOnly(true));

In case of declarative transactions management, use the readOnly parameter of the @Transactional annotation:

@Transactional(readOnly = true)
public void someServiceMethod() {
...