oracle 12c 备份pdb下数据库

1.查看备份目录
SQL> select * from dba_directories;    --查看数据库备份目录。

2.查看需要备份的schema
SQL> show pdbs                         --查看数据库有哪些pdb

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 DB12CPDB                       READ WRITE YES
SQL>  alter session set container=DB12CPDB;          --切换pdb，查看有哪些schemas

Session altered.

SQL> select username,account_status from dba_users where account_status = 'OPEN';   
USERNAME                                                                                                                         ACCOUNT_STATUS
-------------------------------------------------------------------------------------------------------------------------------- --------------------------------
SYS                                                                                                                              OPEN
SYSTEM                                                                                                                           OPEN  
...
3. 查看对应的schema下表的数量：
select table_name,count(1) from dba_tables where username owner in ('SCESS','PDBADMIN');


4. 导出目标数据
expdp \'sys/xxxx@pdb1 as sysdba\' directory=expdp dumpfile=pdb1_20210919_%U.dmp   logfile=exp_pdb1_20210919.log parallel=4

参考：
expdp 'system/"1qaz2wsx"'@ORCL_PDB directory=DBDATA2 dumpfile=DB12CPDB_20210919_%U.dmp logfile=DB12CPDB_20210919.log schemas=SCESS,PDBADMIN COMPRESSION=all PARALLEL=4