Cloning PDB with ADG standby

This article refers to the article ：How to Clone a PDB from a Standby Database in a Data Guard Environment, And completed the whole experimental process .

First you need a ADG Environment , A better way is to use Oracle Vagrant Projects Of OracleDG project .

This project will create 1 Lord 1 Prepared ADG Environmental Science , Version is 19.3. be based on 64GB Memory ,4 OCPU The host of , Creation time 30 About minutes , Very fast .

Create another one on the standby database CDB, Used to host clones PDB. use dbca Silent mode creation , Time in 22 About minutes .

The current architecture is as follows ,PDB1 It is a library that needs to be cloned ：

The above standard DB193H1 and DB193H1_STDBY yes DB_UNIQUE_NAME, The actual database name is DB193H1.

For clarity , We will DB193H1 It is called the main library ,DB193H1_STDBY It is called standby library ,ORCLCDB2 Called the test library .

First , We need to change the standby database to read-only status ：

SQL> show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         3 ORCLPDB1                       MOUNTED
         
SQL> alter pluggable database orclpdb1 open read only;

Pluggable database altered.

SQL> show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         3 ORCLPDB1                       READ ONLY  NO

Because the standby database can only be read-only at most , Therefore, we need to build an additional database to host the cloned PDB. If you directly use the... On the standby database CDB As the target container for cloning , The error will be reported as follows ：

SQL> create pluggable database PDBCLONE from ORCLPDB1;
create pluggable database PDBCLONE from ORCLPDB1
*
ERROR at line 1:
ORA-16000: database or pluggable database open for read-only access

We create a clone administrator on the master database clone_admin, yes common user, He will be used to clone later , After this user is established, it will pass ADG Propagate to the standby database .

create user c##clone_admin identified by Welcome1;
grant create session, resource to c##clone_admin container=all;
grant create pluggable database to c##clone_admin container=all;
grant sysoper to c##clone_admin container=all;
alter user c##clone_admin set container_data=ALL container=current;
grant select on cdb_pdbs to c##clone_admin;

--  In the reference document 1 in , Another method was used , But I didn't try 
grant create session, sysoper to C##SYSOPER identified by SysOperPw__199 container=all;

Then create a test library Database link, Be careful , this Database link It refers to the standby database rather than the primary database , The purpose is to reduce the impact on the main database , And avoid network delays .

SQL> create public database link clone_link connect to c##clone_admin identified by Welcome1 using 'DB193H1_STDBY';

SQL> select pdb_name from cdb_pdbs@clone_link;

PDB_NAME
--------------------------------------------------------------------------------
PDB1
PDB$SEED

At present, our backup database （ Cloned source library ） State the following ：

SQL> show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 PDB1                           READ WRITE NO

At present, our test library （ Target library for cloning ） State the following ：

SQL> show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO

Start the clone in the test library ：

SQL> create pluggable database PDBCLONE from PDB1@clone_link;
create pluggable database PDBCLONE from PDB1@clone_link
*
ERROR at line 1:
ORA-00600: internal error code, arguments: [3647], [19], [16400], [], [], [],
[], [], [], [], [], []

Okay , This is exactly the mistake we expected . Because it is cloned from the standby database , So this error will appear . If you clone from the master library , It won't go wrong , But this is not the scenario we tested today .

MOS This document of Create Pluggable Database From ADG errors out with ORA-600 [3647] (Doc ID 2072550.1), The causes and solutions are introduced in detail . The applicable database versions of this document are 12.1.0.2 to 21.1.

Simply speaking , The solution is to stop redo apply Clone again , After cloning , You can start redo apply.

Be careful , The last clone failed , But there is still a PDB The entry of , We need to delete it first ：

SQL> show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         3 PDBCLONE                       MOUNTED

SQL> drop pluggable database PDBCLONE including datafiles;

Pluggable database dropped.

It can be in the database or DGMGRL Stop in redo apply：

--  In the database 
alter database recover managed standby database cancel ;

-- DGMGRL in 
edit database db193h1_stdby set state = 'apply-off';

This time I succeeded ：

SQL> create pluggable database PDBCLONE from PDB1@clone_link;

Pluggable database created.

SQL> show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         4 PDBCLONE                       MOUNTED
SQL> alter pluggable database pdbclone open;

Pluggable database altered.

SQL> show pdbs

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED
---------- ------------------------------ ---------- ----------
         2 PDB$SEED                       READ ONLY  NO
         4 PDBCLONE                       READ WRITE NO

Now you can recover redo apply 了 ：

--  In the database 
alter database recover managed standby database disconnect ;

-- DGMGRL in 
edit database db193h1_stdby set state = 'apply-on';

To further confirm , I installed in the main library Sample Schema, Repeat the above process , The data is indeed cloned into the test library .

Here are some instructions ：

• The last picture in the original text , It clearly describes the sequence of operations and where they are performed . For... In the standby database PDB, First stop redo apply, then open readonly; After cloning , First close PDB（ Clone Source ）, And then again start redo apply. Although I didn't execute close And the action of , But still follow his process .
• Refreshable PDB Cloning does not support based on ADG standby establish , I won't try this . See Doc ID 2765472.1

Reference resources

1. How to Clone a PDB from a Standby Database in a Data Guard Environment
2. Multitenant : Copying a PDB in a Data Guard Environment in Oracle Database 18c