Oracle 18c 新特性--可刷新PDB的switchover-CFANZ编程社区

说明

在 18c 中支持将通过 dblink 创建的可刷新 PDB 进行源 PDB 和克隆 PDB 进行 switchover ，源 PDB 将成为克隆 PDB ，原来的克隆 PDB 将成为源 PDB 。

具体过程

确认源PDB处于读写模式
以LEIPDB为源PDB来克隆。

SQL> show pdbs;
    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 LEIPDB                         READ WRITE NO

源CDB中创建公共用户

DROP USER c##lei CASCADE;

CREATE USER c##lei IDENTIFIED BY oracle;

GRANT CREATE SESSION, RESOURCE, CREATE ANY TABLE, UNLIMITED TABLESPACE TO c##lei CONTAINER=ALL;

GRANT CREATE PLUGGABLE DATABASE TO c##lei CONTAINER=ALL;

GRANT SYSOPER TO c##lei CONTAINER=ALL;

源PDB中创建测试表

ALTER SESSION SET CONTAINER = leipdb;

CREATE TABLE cndba(id NUMBER);

INSERT INTO cndba VALUES(1);

COMMIT;

SELECT * FROM cndba;
        N1
----------
         1

目标CDB中创建公共用户
源CDB和目标CDB中具有相同的公共用户c##lei。

DROP USER c##lei CASCADE;

CREATE USER c##lei IDENTIFIED BY oracle;

GRANT CREATE SESSION, RESOURCE, CREATE ANY TABLE, UNLIMITED TABLESPACE TO c##lei CONTAINER=ALL;

GRANT CREATE PLUGGABLE DATABASE TO c##lei CONTAINER=ALL;

GRANT SYSOPER TO c##lei CONTAINER=ALL;

目标CDB创建DBLINK
在目标CDB中创建指向源CDB的dblink，用户就用之前创建的c##lei。

配置TNS

LEICDB =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.179)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = lei)
    )
  )

创建dblink

CREATE DATABASE LINK leicdb_dblink CONNECT TO c##lei IDENTIFIED BY oracle USING 'leicdb';

验证DBLINK是否正常

SQL> select COUNT(*) from v$version@leicdb_dblink;
  COUNT(*)
----------
         1

创建手动刷新的PDB

CREATE PLUGGABLE DATABASE leicdb_pdb FROM leipdb@leicdb_dblink

  CREATE_FILE_DEST='/u01/app/oracle/oradata/'

  REFRESH MODE MANUAL;

刷新leicdb_pdb
刷新之前在目标PDB中插入数据

SQL> INSERT INTO cndba VALUES(2);

SQL> select * from cndba;
  ID
----------
   1
   2

SQL> commit;

刷新PDB

ALTER SESSION SET CONTAINER = leicdb_pdb;

ALTER PLUGGABLE DATABASE REFRESH;

查看新数据是否同步过来

ALTER PLUGGABLE DATABASE leicdb_pdb OPEN READ ONLY;

ALTER SESSION SET CONTAINER = leicdb_pdb;

select * from cndba;

  ID
----------
   1
   2

源CDB创建DBLINK
在源CDB中创建指向目标CDB的dblink，用于switchover操作。
同样，也要配置TNS

LEICDB2 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.178)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = lei)
    )
  )

创建dblink

CREATE DATABASE LINK leicdb2_dblink CONNECT TO c##lei IDENTIFIED BY oracle USING 'leicdb2';

验证

select COUNT(*) from v$version@leicdb2_dblink;

COUNT(*)
----------
    1

SWITCHOVER
执行切换操作，和DG switchover很相似切换主备。那么leicdb_pdb就是源PDB，而原来的leipdb就是克隆PDB。

ALTER SESSION SET CONTAINER = leipdb;

ALTER PLUGGABLE DATABASE REFRESH MODE MANUAL FROM leicdb_pdb@leicdb2_dblink SWITCHOVER;

至此就完成了可刷新PDB的在线switchover。