操作如下：
[oracle@ocp77 ~]$ sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Thu May 7 21:25:21 2020
Version 19.7.0.0.0

Copyright © 1982, 2020, Oracle. All rights reserved.

Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.7.0.0.0

SQL> col name for a52
SQL> col value for a24
SQL> col description for a50
SQL> set linesize 150
SQL> select a.ksppinm name,b.ksppstvl value,a.ksppdesc description
2 from x$ksppi a,x$ksppcv b
3 where a.inst_id = USERENV (‘Instance’)
4 and b.inst_id = USERENV (‘Instance’)
5 and a.indx = b.indx
6 and upper(a.ksppinm) LIKE upper(’%&param%’)
7 order by name;
Enter value for param: _exadata_feature_on
old 6: and upper(a.ksppinm) LIKE upper(’%&param%’)
new 6: and upper(a.ksppinm) LIKE upper(’%_exadata_feature_on%’)

NAME VALUE DESCRIPTION

_exadata_feature_on TRUE Exadata Feature On

SQL> alter session set container=pdb1;

Session altered.

SQL> alter pluggable database snapshot pdb1_snapshot;
alter pluggable database snapshot pdb1_snapshot
*
ERROR at line 1:
ORA-00604: error occurred at recursive SQL level 1
ORA-65169: error encountered while attempting to copy file +DATA/CDB1930/A508F7416D0530B3E0534DEAA8C00661/DATAFILE/undotbs1.270.1039785639
ORA-17517: Database cloning using storage snapshot failed on file 8:+DATA/CDB1930/A508F7416D0530B3E0534DEAA8C00661/DATAFILE/undotbs1.270.1039785639

在18.3.0和19.3.0版本下创建均无问题，在19.6.0和19.7.0手工创建快照报错，请各位大侠帮忙分析一下是什么原因？是oracle的bug吗？