Oracle 参数 NONCDB_COMPATIBLE 官方解释，作用，如何配置最优化建议

本站中文解释

NONCDB_COMPATIBLE 用来控制PDB对外建立连接是否使用SID或SERVICE_NAME，在第一个PDB创建时该参数被自动设置，也可以通过ALTER SYSTEM RESET NONCDB_COMPATIBLE命令手工设定。

NONCDB_COMPATIBLE 的可选值为TRUE或FALSE，它设定为TRUE时，CDB中的PDB只能使用SERVICE_NAME建立连接，设定为FALSE时则只能使用PDB的 SID 建立连接。

正确的设置方法：

1、首先通过SQL*Plus连接到cdb ：
sqlplus / as sysdba
2、运行Alter system 命令设置参数：
alter system set noncdb_compatible = TRUE scope=spfile;
3、重启数据库实例：
shutdown immediate
startup
4、查看参数是否生效：
show parameter noncdb

官方英文解释

NONCDB_COMPATIBLE enables you to get behavior similar to a non-CDB when issuing SQL commands inside a PDB in a CDB.

Set this parameter if you are using a single PDB in your CDB configuration and you have legacy code that causes ORA-65040 when you run it in the PDB.

Values

• TRUE

  Indicates the behavior for SQL statements will be like a non-CDB although the statements are issued in a PDB in a CDB.

• FALSE

  Indicates the behavior will for SQL statements will be like a CDB. This is the default value of the parameter.

There are some statements (such as ALTER DB BACKUP CONTROLFILE) which can be issued in a non-CDB, but in a CDB they must be issued in the root (because they affect the whole CDB) and would result in an error if issued in a PDB.

Some ALTER DATABASE or ALTER SYSTEM statements are not permitted inside a PDB, and they will fail if NONCDB_COMPATIBLE=FALSE is set in init.ora. However, these statements will succeed if NONCDB_COMPATIBLE=TRUE is set.

See Also:

• Oracle Multitenant
  Administrator’s Guide for an introduction to PDBs and CDBs

• Oracle Multitenant
  Administrator’s Guide for information about the initialization parameters that control the memory usage of PDBs

• Oracle Multitenant
  Administrator’s Guide for information about the ALTER SYSTEM statements that can be run in a PDB.