Adaptive plans are one of the new features in Oracle 12C. An adaptive plan has built-in options that enable the final plan for a statement to differ from the default plan. During the first execution of a SQL statement, before a specific subplan becomes active, the oracle cost based optimizer makes a final decision about which option to use. The optimizer bases its choice on observations made during the execution up to this point. The ability of the optimizer to adapt plans can improve query performance.