11.7.4. Nested Transactions

Nested transactions allow an application to create a transaction that is embedded in an existing transaction. In this model, multiple subtransactions can be embedded recursively in a transaction. Subtransactions can be committed or rolled back without committing or rolling back the parent transaction. However, the results of a commit operation are contingent upon the commitment of all the transaction's ancestors.
For implementation specific information, refer JBossTS JTS Development guide at https://docs.jboss.org/jbosstm/latest/guides/narayana-jts-development_guide.
Nested transactions are only supported when you use distributed transactions, with the JTS API. In addition, many database vendors do not support nested transactions, so consult your database vendor before you add nested transactions to your application.