In Oracle Database 12c, when does a transaction begin?
A.
when a transaction ID is allocated for it.
B.
when a user explicitly issues a “begin” statement
C.
when a transaction is assigned to an available undo data segment to record undo entries for the new
transaction
D.
when the first executable SQL statement is encountered
Explanation:
https://docs.oracle.com/database/121/CNCPT/transact.htm#CNCPT038