用PDB$SEED创建pdb数据库

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用PDB$SEED创建pdb数据库

Oracle 12C引入了新特性多租用户环境（Multitenant Environment），它允许一个数据库容器:CDB(Container Database)承载多个可插拔数据库:PDB(Pluggable Database)。在Oracle 12C之前，实例与数据库是一对一或多对一关系（RAC）,而不能实现一对多的关系。在Oracle 12C中，基于多租用户环境这一新特性，实现了实例与数据库的一对多关系。 下图是官方文档给出的CDB与PDB的关系图。

 从上图可以看到，CDB由三部分组成
1.Root,即CDB$ROOT，存储数据库系统元数据和公用数据，Oracle不建议在CDB$ROOT下修改和创建任何数据，一个CDB有且只有一个root.
2.seed,即PDB$SEED，它是一个PDB模板，PDB都是基于此模板创建，一个CDB只有一个PDB$SEED
3.PDBs,每个PDB都可看做一个单独的数据库，所有的PDB都属于CDB$ROOT，一个CDB可以有多个PDB。

根据PDB$SEED创建PDB

1.查看pdb$seed数据文件路径：

select name from v$datafile where con_id=(select con_id from v$pdbs where name='PDB$SEED');

SQL>  select name from v$datafile where con_id=(select con_id from v$pdbs where name='PDB$SEED');NAME
----------------------------------------------------------------------
/u01/app/oracle/oradata/ORCL/pdbseed/system01.dbf
/u01/app/oracle/oradata/ORCL/pdbseed/sysaux01.dbf
/u01/app/oracle/oradata/ORCL/pdbseed/undotbs01.dbf

2.查看pdb$seed临时文件路径：

 select name from v$tempfile where con_id=(select con_id from v$pdbs where name='PDB$SEED');

SQL> select name from v$tempfile where con_id=(select con_id from v$pdbs where name='PDB$SEED');NAME
----------------------------------------------------------------------
/u01/app/oracle/oradata/ORCL/pdbseed/temp012023-03-05_22-04-42-624-PM.
dbf

创建PDB

CREATE PLUGGABLE DATABASE pdb4 ADMIN USER pdb_adm4 IDENTIFIED BY 123456 
FILE_NAME_CONVERT=
('/u01/app/oracle/oradata/ORCL/pdbseed/system01.dbf','/u01/app/oracle/oradata/ORCL/pdb4/system.dbf', 
'/u01/app/oracle/oradata/ORCL/pdbseed/sysaux01.dbf','/u01/app/oracle/oradata/ORCL/pdb4/sysaux.dbf', 
'/u01/app/oracle/oradata/ORCL/pdbseed/undotbs01.dbf','/u01/app/oracle/oradata/ORCL/pdb4/undotbs1.dbf',
'/u01/app/oracle/oradata/ORCL/pdbseed/temp012023-03-05_22-04-42-624-PM.dbf','/u01/app/oracle/oradata/ORCL/pdb4/temp.dbf');

SQL> CREATE PLUGGABLE DATABASE pdb4 ADMIN USER pdb_adm4 IDENTIFIED BY 123456 2  FILE_NAME_CONVERT=3  ('/u01/app/oracle/oradata/ORCL/pdbseed/system01.dbf','/u01/app/oracle/oradata/ORCL/pdb4/system.dbf', 4  '/u01/app/oracle/oradata/ORCL/pdbseed/sysaux01.dbf','/u01/app/oracle/oradata/ORCL/pdb4/sysaux.dbf', 5  '/u01/app/oracle/oradata/ORCL/pdbseed/undotbs01.dbf','/u01/app/oracle/oradata/ORCL/pdb4/undotbs1.dbf',6  '/u01/app/oracle/oradata/ORCL/pdbseed/temp012023-03-05_22-04-42-624-PM.dbf','/u01/app/oracle/oradata/ORCL/pdb4/temp.dbf');Pluggable database created.

查看新建的PDB

show pdbs

SQL> show pdbsCON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------2 PDB$SEED                       READ ONLY  NO3 PDB1                           READ WRITE NO4 PDB2                           READ WRITE NO5 PDB4                           MOUNTED6 PDB3                           READ WRITE NO

启动新建的PDB4

alter pluggable database PDB4 open;

SQL> alter pluggable database PDB4 open;Pluggable database altered.SQL> show pdbs;CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------2 PDB$SEED                       READ ONLY  NO3 PDB1                           READ WRITE NO4 PDB2                           READ WRITE NO5 PDB4                           READ WRITE NO6 PDB3                           READ WRITE NO

切换到PDB4

alter session set container=PDB4;

SQL> alter session set container=PDB4;Session altered.SQL> show con_name;CON_NAME
------------------------------
PDB4