新特性：CDB/PDB的维护命令：修改PDB系统参数，不影响CDB与其他的PDB

修改PDB系统参数，不影响CDB与其他的PDB

SQL> set linesize 200
SQL> show parameter optimizer_use_sql_plan_baselines

NAME                                 TYPE                              VALUE
------------------------------------ --------------------------------- ------------------------------
optimizer_use_sql_plan_baselines     boolean                           TRUE
SQL> show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 PDB1_WHS                       READ WRITE NO
         4 PDB2_WHS                       MOUNTED
         5 PDB3_WHS                       READ WRITE NO
SQL> alter session set container=PDB1_WHS;

Session altered.

SQL> show parameter optimizer_use_sql_plan_baselines

NAME                                 TYPE                              VALUE
------------------------------------ --------------------------------- ------------------------------
optimizer_use_sql_plan_baselines     boolean                           TRUE

SQL> alter system set optimizer_use_sql_plan_baselines=false scope=both;

System altered.

SQL> show parameter optimizer_use_sql_plan_baselines;

NAME                                 TYPE                              VALUE
------------------------------------ --------------------------------- ------------------------------
optimizer_use_sql_plan_baselines     boolean                           FALSE

这里可以看到optimizer_use_sql_plan_baselines已经是false，看看其他pdb与CDB的参数是什么值

SQL> alter session set container=PDB3_WHS;

Session altered.

SQL> show parameter optimizer_use_sql_plan_baselines;

NAME                                 TYPE                              VALUE
------------------------------------ --------------------------------- ------------------------------
optimizer_use_sql_plan_baselines     boolean                           TRUE
SQL> exit
Disconnected from Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0
[oracle@cat1 ~]$ sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Sun May 1 21:55:53 2005
Version 19.3.0.0.0

Copyright (c) 1982, 2019, Oracle.  All rights reserved.

Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.3.0.0.0

SQL> set linesize 200
SQL> show parameter optimizer_use_sql_plan_baselines

NAME                                 TYPE                              VALUE
------------------------------------ --------------------------------- ------------------------------
optimizer_use_sql_plan_baselines     boolean                           TRUE
SQL>