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Oracle 12c R2版本 Application Containers 特性(一)

Oracle 12c R2版本 Application Containers 特性(二)

Application Seed

Application seed与CDB中的PDB$SEED类似，在使用Application seed做为Application PDBs的创建模板时，你可以快速且容易的创建一个满足要求的Application PDB，Application Container中最多只能创建一个Application seed，当然也可不包含Application seed。

我们可以在Application root中使用CREATE PLUGGABLE DATABASE带有AS SEED子句来创建Application seed，创建时，Application seed可以有如下几种来源，比如CDB seed、克隆现有的PDB或non-CDB以及插入已拔出的PDB，在使用AS SEED子句创建Application seed时，不要需要为其指定名称，固定的命名规则为application_container_name$SEED，例如在Application Container：qdatacon1中创建的Application seed将被命名为qdatacon1$SEED。

（Application Container特性架构图）

如下为使用不同来源创建Application seed的步骤：

1. Creating an Application Seed From the CDB Seed

CREATE PLUGGABLE DATABASE AS SEED ADMIN USER qdadm IDENTIFIED BY password;

ALTER PLUGGABLE DATABASE qdatacon1$SEED OPEN;

ALTER SESSION SET CONTAINER=qdatacon1$SEED;

ALTER PLUGGABLE DATABASE APPLICATION ALL SYNC;

ALTER PLUGGABLE DATABASE CLOSE IMMEDIATE;

ALTER PLUGGABLE DATABASE OPEN READ ONLY;

2. Creating an Application Seed From an Application PDB

CREATE PLUGGABLE DATABASE AS SEED FROM qdcpdb1;

ALTER PLUGGABLE DATABASE qdatacon1$SEED OPEN;

ALTER PLUGGABLE DATABASE CLOSE IMMEDIATE;

ALTER PLUGGABLE DATABASE OPEN READ ONLY;

3. Creating an Application Seed From an Application Root

CREATE PLUGGABLE DATABASE AS SEED FROM qdatacon1;

ALTER PLUGGABLE DATABASE qdatacon1$SEED OPEN;

ALTER SESSION SET CONTAINER=qdatacon1$SEED;

@$ORACLE_HOME/rdbms/admin/pdb_to_apppdb.sql

ALTER PLUGGABLE DATABASE CLOSE IMMEDIATE;

ALTER PLUGGABLE DATABASE OPEN READ ONLY;

删除Application seed时与删除其他PDB的方式相同，如下：

ALTER SESSION SET CONTAINER=qdatacon1;

ALTER PLUGGABLE DATABASE qdatacon1$SEED CLOSE;

DROP PLUGGABLE DATABASE qdatacon1$SEED INCLUDING DATAFILES;

Application Container相关视图

下面列出了在Application Container特性下可能会使用到的视图，并对视图做了简单描述。

dba_pdbs

该视图记录了CDB中PDB与Application Container的信息，我们可以通过层次查询将PDB以及Application root与Application PDB的关系一目了然的展现出来，如下所示：

SELECT LPAD(' ', (LEVEL - 1) * 2, ' ') || pdb_name AS pdb_name,

       application_root,

       application_pdb,

       application_seed,

       status,

       pdb_id,

       application_root_con_id

  FROM cdb_pdbs

START WITH application_root_con_id IS NULL

CONNECT BY PRIOR pdb_id = APPLICATION_ROOT_CON_ID

ORDER SIBLINGS BY pdb_id;