oracle 12c 在cdb级别开启闪回，pdb是否受影响

如下实验测试在cdb级别开启数据库闪回，pdb级别是否也会开启？
SQL> show con_name;

CON_NAME

CDB$ROOT
SQL> select FLASHBACK_ON from v$database;

FLASHBACK_ON

YES

SQL> show pdbs;

CON_ID CON_NAME OPEN MODE RESTRICTED

2 PDB$SEED READ ONLY NO
3 RACDB1PDB MOUNTED
SQL> alter pluggable database racdb1pdb open;

Pluggable database altered.

SQL> alter session set container=racdb1pdb;

Session altered.

SQL> select FLASHBACK_ON from v$database;

FLASHBACK_ON

YES

SQL>

总结：在cdb级别开启数据库闪回，pdb级别也会开启。