## 16.4. Visibility

Visibility rules work as in the case of independent transactions executed via `dblink`. T1 does not see the effects of T0, because the latter has not been committed yet. T0 might see the effects of T1, depending on its own transaction isolation mode. In case of Read Committed isolation level the parent transaction will see changes made by autonomous transactions. But in case of Repeatable Read isolation level the parent transaction will not see changes made by autonomous transactions.

Now single-session deadlocks become possible, because an autonomous transaction can become entangled with one of the paused transactions in its session. Autonomous transaction T1 is assumed to depend on parent transaction T0 and if it attempts to obtain any resource locked by T0, then deadlock is reported.