Administering PDB

Administering a pluggable database (PDB) involves a subset of the tasks required to administer a non-CDB.

In this subset of tasks, most are the same for a PDB and a non-CDB, but differences exist. For example, there are differences when you modify the open mode of a PDB. Also, a PDB administrator is limited to managing a single PDB and cannot manage other PDBs in the multitenant container database (CDB).

Tasks Common to PDBs and Non-CDBs

Most administrative tasks are the same for a PDB and a non-CDB.

When you are administering a PDB, you can modify the PDB with an ALTER DATABASE, ALTER PLUGGABLE DATABASE, or ALTER SYSTEM statement. You can also execute DDL statements on the PDB. The following table describes some of these tasks common to a PDB and non-CDB.

Administrative Tasks Common to PDBs and Non-CDBs

Tasks Specific to CDBs

Some administrative tasks cannot be performed when the current container is a PDB.

The following tasks are performed by a common user for the entire CDB or for the CDB root when the current container is the root:

• Starting up and shutting down a CDB instance
• Modifying the CDB or the root with an ALTER DATABASE statement
• Modifying the CDB or the root with an ALTER SYSTEM statement
• Executing data definition language (DDL) statements on a CDB or the root
• Managing the following components:
  • Processes
  • Memory
  • Errors and alerts
  • Diagnostic data
  • Control files
  • The online redo log and the archived redo log files
  • Undo
• Creating, plugging in, unplugging, and dropping PDBs

A common user whose current container is the root can also change the open mode of one or more PDBs. Similarly, a common user or local user whose current container is a PDB can change the open mode of the current PDB.

Managing Connections to a PDB

You manage connections for a PDB in the same way as for a non-CDB, with some special considerations.

Connecting to a PDB

You can use several techniques to connect to a PDB with the SQL*Plus CONNECT command.

This section assumes that you understand how to connect to a non-CDB in SQL*Plus.

You can use the following techniques to connect to a PDB with the SQL*Plus CONNECT command:

• Local connection with operating system authentication
• Database connection using easy connect
• Database connection using a net service name

To connect to a PDB using the SQL*Plus CONNECT command:

1. Configure your environment so that you can open SQL*Plus.
2. Start SQL*Plus with the /NOLOG argument:

sqlplus /nolog

• Issue a CONNECT command using easy connect or a net service name to connect to the PDB.

To connect to a PDB, connect to a service with a PDB property.

Connecting to a PDB in SQL*Plus Using the PDB’s Net Service Name

The following command connects to the hr user using the hrapp service. The hrapp service has a PDB property for the hrpdb PDB. This example assumes that the client is configured to have a net service name for the hrapp service.

CONNECT [email protected]

Managing Services for PDBs

You can create, modify, or remove services for a PDB.

Services for PDBs

Each PDB has a default service, but you can create your own using SRVCTL or DBMS_SERVICE.

The PDB Property

The PDB property associates a service with a PDB. When a client connects to a service with a PDB property, the current container for the connection is the PDB.

The PDB property is required only when you do either of the following:

• Create a service
• Modify the PDB property of a service

You do not specify a PDB property when you start, stop, or remove a service. Also, you do not need to specify a PDB property when you modify a service without modifying its PDB property.

You can view the PDB property for a service by querying the ALL_SERVICES data dictionary view. Alternatively, when using the SRVCTL utility, you can use the srvctl config service command.

Default and User-Defined Services

Creating a PDB creates a new default service for the PDB automatically.

Each database service name must be unique in a CDB, and each database service name must be unique within the scope of all the CDBs whose instances are reached through a specific listener. The default service has the same name as the PDB. You cannot manage this service, which you should only use for administrative tasks.

Always use user-defined services for applications. The reason is that you can customize user-defined services to fit the requirements of your applications. Oracle recommends that you not use the default PDB service for applications.

In an Oracle Clusterware environment, you must create an Oracle Clusterware resource for each service that is created for the PDB. When your database is being managed by Oracle Restart or Oracle Clusterware, and when you use the SRVCTL utility to start a service with a PDB property for a PDB that is closed, the PDB is opened in read/write mode on the nodes where the service is started. However, stopping a PDB service does not change the open mode of the PDB.

When you unplug or drop a PDB, the services of the unplugged or dropped PDB are not removed automatically. You can remove these services manually.

Tools for Managing Services

Oracle recommends using the SRVCTL utility to create and modify services. Alternatively, you can use the DBMS_SERVICE package.

SRVCTL

If your single-instance database is being managed by Oracle Restart or your Oracle RAC database is being managed by Oracle Clusterware, then use the Server Control (SRVCTL) utility to create, modify, or remove the service.

To create a service for a PDB using the SRVCTL utility, use the add service command and specify the PDB in the -pdb parameter. If you do not specify -pdb, then the service is associated with the root.

To modify the PDB property of a service using the SRVCTL utility, use the modify service command and specify the PDB in the -pdb parameter. To remove a service for a PDB using the SRVCTL utility, use the remove service command.

You can use other SRVCTL commands to manage the service, such as the start service, stop service, and relocate service commands, even if they do not include the -pdb parameter.

The PDB name is not validated when you create or modify a service with the SRVCTL utility. However, an attempt to start a service with invalid PDB name results in an error.

DBMS_SERVICE

If your database is not being managed by Oracle Restart or Oracle Clusterware, then use the DBMS_SERVICE package to create or remove a database service.

DBMS_SERVICE exists at the root level and in each PDB. It is owned and executed by SYS at each level. A PDB administrator cannot stop, relocate, or test the connection for a service that is owned by another PDB.

When you create a service with the DBMS_SERVICE package, the PDB property of the service is set to the current container. Therefore, to create a service with a PDB property set to a specific PDB using the DBMS_SERVICE package, run the CREATE_SERVICE procedure when the PDB is the current container. If you create a service using the CREATE_SERVICE procedure when the current container is the root, then the service is associated with the root.

You cannot modify the PDB property of a service with the DBMS_SERVICE package. However, you can remove a service in one PDB and create a similar service in a different PDB. In this case, the new service has the PDB property of the PDB in which it was created.

You can also use other DBMS_SERVICE subprograms to manage the service, such as the START_SERVICE and STOP_SERVICE procedures. You can use DBMS_SERVICE.*_CONNECTION_TEST procedures to check the health of a database connection during planned maintenance. Use the DELETE_SERVICE procedure to remove a service.

Managing Services for a PDB Using SRVCTL and DBMS_SERVICE

You can create, modify, or remove a service with a PDB property.

To manage a service with a PDB property using the SRVCTL utility:

1. Log in to the host computer with the correct user account.
2. Ensure that you run SRVCTL from the correct Oracle home.
3. Perform one of the following operations:
   1. To create or modify a service, run the add service command, and specify the PDB in the -pdb parameter.
   1. To modify the PDB property of a service, run the modify service command, and specify the PDB in the -pdb parameter.
   1. To remove a service, run the remove service command.

To create or remove a service for a PDB using the DBMS_SERVICE package:

1. In SQL*Plus, ensure that the current container is a PDB.
2. Run the appropriate subprogram in the DBMS_SERVICE package.

Creating a Service for a PDB Using the SRVCTL Utility

This example adds the salesrep service for the PDB salespdb in the CDB with DB_UNIQUE_NAME mycdb:

srvctl add service -db mycdb -service salesrep -pdb salespdb

Modifying the PDB Property of a Service Using the SRVCTL Utility

This example modifies the salesrep service in the CDB with DB_UNIQUE_NAME mycdb to associate the service with the hrpdb PDB:

srvctl modify service 

  -db mycdb 

  -service salesrep 

  -pdb hrpdb

Relocating a Service in Oracle RAC Using the SRVCTL Utility

You can use the relocate service command to relocate a service from one Oracle RAC instance, where the service is currently running, to another instance, where it can run. This technique applies both to services for administrator-managed databases as well as singleton services for policy-managed databases.

The following command relocates service svc1 from Oracle RAC instance cdb_inst1, where it is currently running, to instance cdb_inst2, where it is currently not running:

srvctl relocate service 

  ­db cdb 

  ­service svc1 

  ­oldinst cdb_inst1 

  ­newinst cdb_inst2 

  –drain_timeout NNN 

  –stopoption immediate

The following command performs the same operation for a policy-managed database:

srvctl relocate service 

  ­db cdb 

  ­service svc1 

  ­currentnode cdb_inst1 

  ­targetnode cdb_inst2 

  –drain_timeout NNN 

  –stopoption immediate

Removing a Service Using the SRVCTL Utility

This example removes the salesrep service in the CDB with DB_UNIQUE_NAME mycdb:

srvctl remove service 

  -db mycdb 

  -service salesrep

Creating a Service for a PDB Using the DBMS_SERVICE Package

This example creates the salesrep service for the current PDB:

BEGIN

  DBMS_SERVICE.CREATE_SERVICE(

    service_name => 'salesrep',

    network_name => 'salesrep.example.com');

END;

/

The PDB property of the service is set to the current container. For example, if the current container is the salespdb PDB, then the PDB property of the service is salespdb.

Removing a Service Using the DBMS_SERVICE Package

This example removes the salesrep service in the current PDB.

BEGIN

  DBMS_SERVICE.DELETE_SERVICE(

    service_name => 'salesrep');

END;

/

Modifying the Listener Settings of a Referenced PDB

A PDB that is referenced by a proxy PDB is called a referenced PDB.

When the port or host name changes for the listener of the referenced PDB, you must modify the listener settings of the referenced PDB so that its proxy PDBs continue to function properly.

Altering the Listener Host Name of a Referenced PDB

When the host name of the listener for a referenced PDB changes, you must run an ALTER PLUGGABLE DATABASE CONTAINERS HOST statement to reset the host name of the referenced PDB so that its proxy PDBs continue to function properly.

A proxy PDB uses a database link to establish communication with its referenced PDB during PDB creation. After communication is established, the proxy PDB communicates directly with the referenced PDB without using a database link, and the database link can be dropped. When the listener host name changes for the referenced PDB, each proxy PDB must reestablish communication with its referenced PDB.

The listener host name of a referenced PDB is a database property. When it is set, you can view the current setting by querying the DATABASE_PROPERTIES data dictionary view.

The current user must have the ALTER DATABASE system privilege, and the privilege must be either commonly granted or locally granted in the PDB.

1. In SQL*Plus, ensure that the current container is the referenced PDB.
2. Run an ALTER PLUGGABLE DATABASE CONTAINERS HOST statement and specify the new host name, or include the RESET keyword to return the host name to its default setting, which is the host name of the referenced PDB.
3. Drop and re-create the proxy PDBs that reference the referenced PDB to reestablish communication for each proxy PDB and its referenced PDB.

Altering the Listener Host Name of a Referenced PDB

This example changes the host name for the referenced PDB to myhost.example.com.

ALTER PLUGGABLE DATABASE CONTAINERS HOST='myhost.example.com';

Resetting the Listener Host Name to the Default Value

This example resets the host name for the referenced PDB to its default value. The default value is the host name of the referenced PDB.

ALTER PLUGGABLE DATABASE CONTAINERS HOST RESET;

Altering the Listener Port Number of a Referenced PDB

When the port number of the listener for a referenced PDB changes, you must run an ALTER PLUGGABLE DATABASE CONTAINERS PORT statement to reset the port number of the referenced PDB so that its proxy PDBs continue to function properly.

A proxy PDB uses a database link to establish communication with its referenced PDB during PDB creation. After communication is established, the proxy PDB communicates directly with the referenced PDB without using a database link, and the database link can be dropped. When the listener port number changes for the referenced PDB, each proxy PDB must re-establish communication with its referenced PDB.

The listener port number of a referenced PDB is a database property. When it is set, you can view the current setting by querying the DATABASE_PROPERTIES data dictionary view.

The current user must have the ALTER DATABASE system privilege, and the privilege must be either commonly granted or locally granted in the PDB.

1. In SQL*Plus, ensure that the current container is the referenced PDB.
2. Run an ALTER PLUGGABLE DATABASE CONTAINERS PORT statement and specify the new port number, or include the RESET keyword to return the port number to its default setting, which is 1521.
3. Drop and re-create the proxy PDBs that reference the referenced PDB to re-establish communication for each proxy PDB and its referenced PDB.

Altering the Listener Port Number of a Referenced PDB

This example changes the port number for the referenced PDB to 1543.

ALTER PLUGGABLE DATABASE CONTAINERS PORT=1543;

Resetting the Listener Port Number to the Default Value

This example resets the port number for the referenced PDB to its default value. The default value for the port number is 1521.

ALTER PLUGGABLE DATABASE CONTAINERS PORT RESET;

Modifying a PDB at the System Level

The ALTER SYSTEM statement can dynamically alter a PDB. You can issue an ALTER SYSTEM statement when you want to change the way a PDB operates.

When the current container is a PDB, you can run the following ALTER SYSTEM statements:

• ALTER SYSTEM FLUSH { SHARED_POOL | BUFFER_CACHE | FLASH_CACHE }
• ALTER SYSTEM { ENABLE | DISABLE } RESTRICTED SESSION
• ALTER SYSTEM SET USE_STORED_OUTLINES
• ALTER SYSTEM { SUSPEND | RESUME }
• ALTER SYSTEM CHECKPOINT
• ALTER SYSTEM CHECK DATAFILES
• ALTER SYSTEM REGISTER
• ALTER SYSTEM { KILL | DISCONNECT } SESSION
• ALTER SYSTEM SET initialization_parameter (for a subset of initialization parameters)

All other ALTER SYSTEM statements affect the entire CDB and must be run by a common user in the root.

The ALTER SYSTEM SET initialization_parameter statement can modify only some initialization parameters for PDBs. All initialization parameters can be set for the root. For any initialization parameter that is not set explicitly for a PDB, the PDB inherits the parameter value from the root.

You can modify an initialization parameter for a PDB when the ISPDB_MODIFIABLE column is TRUE for the parameter in the V$SYSTEM_PARAMETER view. The following query lists all initialization parameters that are modifiable for a PDB:

SELECT NAME 

FROM   V$SYSTEM_PARAMETER 

WHERE  ISPDB_MODIFIABLE='TRUE' 

ORDER BY NAME;

When the current container is a PDB, run the ALTER SYSTEM SET initialization_parameter statement to modify the PDB. The statement does not affect the root or other PDBs. The following table describes the behavior of the SCOPE clause when you use a server parameter file (SPFILE) and run the ALTER SYSTEM SET statement on a PDB.

When a PDB is unplugged from a CDB, the values of the initialization parameters that were specified for the PDB with SCOPE=BOTH or SCOPE=SPFILE are added to the PDB’s XML metadata file. These values are restored for the PDB when it is plugged in to a CDB.

Modifying a PDB with ALTER SYSTEM

To modify a PDB at the system level, use the ALTER SYSTEM statement (just as for a non-CDB).

Prerequisites

The current user must be granted the following privileges, which must be either commonly granted or locally granted in the PDB:

• CREATE SESSION
• ALTER SYSTEM

To use ALTER SYSTEM to modify a PDB:

1. In SQL*Plus, ensure that the current container is a PDB.
2. Run the ALTER SYSTEM statement.

Enable Restricted Sessions in a PDB

To restrict sessions in a PDB, issue the following statement:

ALTER SYSTEM ENABLE RESTRICTED SESSION;

Changing the Statistics Gathering Level for the PDB

This ALTER SYSTEM statement sets the STATISTICS_LEVEL initialization parameter to ALL for the current PDB:

ALTER SYSTEM SET STATISTICS_LEVEL = ALL SCOPE = MEMORY;

Modifying a PDB at the Database Level

The ALTER PLUGGABLE DATABASE for a PDB is analogous to the ALTER DATABASE for a non-CDB.

Storage Clauses

Use ALTER PLUGGABLE DATABASE to configure storage at the PDB level.

The following clauses of ALTER PLUGGABLE DATABASE modify PDB storage:

• database_file_clauses

These clauses work the same as they would in an ALTER DATABASE statement, but the statement applies to the current PDB.

• DEFAULT TABLESPACE clause

For users created while the current container is a PDB, this clause specifies the default tablespace for the user if the default tablespace is not specified in the CREATE USER statement.

• DEFAULT TEMPORARY TABLESPACE clause

For users created while the current container is a PDB, this clause specifies the default temporary tablespace for the user if the default temporary tablespace is not specified in the CREATE USER statement.

• SET DEFAULT { BIGFILE | SMALLFILE } TABLESPACE clause

This clause changes the default type of subsequently created tablespaces in the PDB to either bigfile or smallfile. This clause works the same as it would in an ALTER DATABASE statement, but it applies to the current PDB.

• pdb_storage_clause

This clause sets a limit on the amount of storage used by all tablespaces that belong to a PDB. This limit applies to the total size of all data files and temp files comprising tablespaces that belong to the PDB.

This clause can also set a limit on the amount of storage that can be used by unified audit OS spillover (.bin format) files in the PDB. If the limit is reached, then no additional storage is available for these files.

This clause can also set a limit on the amount of storage in a shared temporary tablespace that can be used by sessions connected to the PDB. If the limit is reached, then no additional storage in the shared temporary tablespace is available to sessions connected to the PDB.

Logging and Recovery Clauses

Use ALTER PLUGGABLE DATABASE to set logging and recovery and recovery modes at the PDB level.

logging_clause

This clause specifies the logging attribute of the PDB. The logging attribute controls whether certain DML operations are logged in the redo log file (LOGGING) or not (NOLOGGING).

You can use this clause to specify one of the following attributes:

• LOGGING indicates that any future tablespaces created within the PDB will be created with the LOGGING attribute by default. You can override this default logging attribute by specifying NOLOGGING at the schema object level, in a CREATE TABLE statement for example.
• NOLOGGING indicates that any future tablespaces created within the PDB will be created with the NOLOGGING attribute by default. You can override this default logging attribute by specifying LOGGING at the schema object level, in a CREATE TABLE statement for example.

The specified attribute is used to establish the logging attribute of tablespaces created within the PDB if the logging_clause is not specified in the CREATE TABLESPACE statement.

The DBA_PDBS view shows the current logging attribute for a PDB.

pdb_force_logging_clause

This clause places a PDB into force logging or force nologging mode or takes a PDB out of force logging or force nologging mode.

You can use this clause to specify one of the following attributes:

• ENABLE FORCE LOGGING places the PDB in force logging mode, which causes all changes in the PDB, except changes in temporary tablespaces and temporary segments, to be logged. Force logging mode cannot be overridden at the schema object level.

PDB-level force logging mode takes precedence over and is independent of any NOLOGGING or FORCE LOGGING settings you specify for individual tablespaces in the PDB and any NOLOGGING settings you specify for individual database objects in the PDB.

ENABLE FORCE LOGGING cannot be specified if a PDB is in force nologging mode. DISABLE FORCE NOLOGGING must be specified first.

• DISABLE FORCE LOGGING takes a PDB which is currently in force logging mode out of that mode. If the PDB is not in force logging mode currently, then specifying DISABLE FORCE LOGGING results in an error.
• ENABLE FORCE NOLOGGING places the PDB in force nologging mode, which causes no changes in the PDB to be logged. Force nologging mode cannot be overridden at the schema object level.

CDB-wide force logging mode supersedes PDB-level force nologging mode. PDB-level force nologging mode takes precedence over and is independent of any LOGGING or FORCE LOGGING settings you specify for individual tablespaces in the PDB and any LOGGING settings you specify for individual database objects in the PDB.

ENABLE FORCE NOLOGGING cannot be specified if a PDB is in force logging mode. DISABLE FORCE LOGGING must be specified first.

• DISABLE FORCE NOLOGGING takes a PDB that is currently in force nologging mode out of that mode. If the PDB is not in force nologging mode currently, then specifying DISABLE FORCE NOLOGGING results in an error.

The DBA_PDBS view shows whether a PDB is in force logging or force nologging mode.

pdb_recovery_clause

ALTER PLUGGABLE DATABASE DISABLE RECOVERY takes the data files that belong to the PDB offline and disables recovery of the PDB. The PDB data files are not part of any recovery session until it is enabled again. Any new data files created while recovery is disabled are created as unnamed files for the PDB.

ALTER PLUGGABLE DATABASE ENABLE RECOVERY brings the data files that belong to the PDB online and marks the PDB for active recovery. Recovery sessions include these files.

Check the recovery status of a PDB by querying the RECOVERY_STATUS column in the V$PDBS view.

Miscellaneous Clauses

You can use ALTER PLUGGABLE DATABASE to modify the open mode, global name, time zone, and default edition.

When the current container is a PDB, an ALTER PLUGGABLE DATABASE statement with any of the following clauses modifies the PDB:

• pdb_change_state_clause

This clause changes the open mode of the current PDB.

If you specify the optional RESTRICTED keyword, then the PDB is accessible only to users with the RESTRICTED SESSION privilege in the PDB.

Specifying FORCE in this clause changes semantics of the ALTER PLUGGABLE DATABASE statement so that, in addition to opening a PDB that is currently closed, it can be used to change the open mode of a PDB that is already open.

• RENAME GLOBAL_NAME clause

This clause changes the unique global database name for the PDB. The new global database name must be different from that of any container in the CDB. When you change the global database name of a PDB, the PDB name is changed to the name before the first period in the global database name.

You must change the PDB property of database services used to connect to the PDB when you change the global database name.

• set_time_zone_clause

This clause works the same as it would in an ALTER DATABASE statement, but it applies to the current PDB.

• DEFAULT EDITION clause

This clause works the same as it would in an ALTER DATABASE statement, but it applies to the current PDB. Each PDB can use edition-based redefinition, and editions in one PDB do not affect editions in other PDBs. In a multitenant environment in which each PDB has its own application, you can use edition-based redefinition independently for each distinct application.

Modifying a PDB with the ALTER PLUGGABLE DATABASE Statement

To modify the attributes of a single PDB, use the ALTER PLUGGABLE DATABASE statement.

When the current container is a PDB, an ALTER PLUGGABLE DATABASE statement modifies the PDB. The modifications overwrite the defaults set for the root in the PDB. The modifications do not affect the CDB root or other PDBs.

To modify a PDB:

1. In SQL*Plus, ensure that the current container is a PDB.
2. Run an ALTER PLUGGABLE DATABASE statement.

Changing the Open Mode of a PDB

This ALTER PLUGGABLE DATABASE statement changes the open mode of the current PDB to mounted.

ALTER PLUGGABLE DATABASE CLOSE IMMEDIATE;

The following statement changes the open mode of the current PDB to open read-only.

ALTER PLUGGABLE DATABASE OPEN READ ONLY;

A PDB must be in mounted mode to change its open mode to read-only or read/write unless you specify the FORCE keyword.

The following statement changes the open mode of the current PDB from mounted or open read-only to open read/write.

ALTER PLUGGABLE DATABASE OPEN FORCE;

The following statement changes the open mode of the current PDB from mounted to migrate.

ALTER PLUGGABLE DATABASE OPEN UPGRADE;

Bringing a Data File Online for a PDB

This ALTER PLUGGABLE DATABASE statement uses a database_file_clause to bring the /u03/oracle/pdb1_01.dbf data file online.

ALTER PLUGGABLE DATABASE DATAFILE '/u03/oracle/pdb1_01.dbf' ONLINE;

Changing the Default Tablespaces for a PDB

This ALTER PLUGGABLE DATABASE statement uses a DEFAULT TABLESPACE clause to set the default permanent tablespace to pdb1_tbs for the PDB.

ALTER PLUGGABLE DATABASE DEFAULT TABLESPACE pdb1_tbs;

This ALTER PLUGGABLE DATABASE statement uses a DEFAULT TEMPORARY TABLESPACE clause to set the default temporary tablespace to pdb1_temp for the PDB.

ALTER PLUGGABLE DATABASE DEFAULT TEMPORARY TABLESPACE pdb1_temp;

The tablespace or tablespace group specified in the ALTER PLUGGABLE DATABASE statement must exist in the PDB. Users whose current container is a PDB that are not explicitly assigned a default tablespace or default temporary tablespace use the default tablespace or default temporary tablespace for the PDB.

Changing the Default Tablespace Type for a PDB

This ALTER DATABASE statement uses a SET DEFAULT TABLESPACE clause to change the default tablespace type to bigfile for the PDB.

ALTER PLUGGABLE DATABASE SET DEFAULT BIGFILE TABLESPACE;

Setting Storage Limits for a PDB

This statement sets the storage limit for all tablespaces that belong to a PDB to two gigabytes.

ALTER PLUGGABLE DATABASE STORAGE(MAXSIZE 2G);

This statement specifies that there is no storage limit for the tablespaces that belong to the PDB.

ALTER PLUGGABLE DATABASE STORAGE(MAXSIZE UNLIMITED);

This statement specifies that there is no storage limit for the tablespaces that belong to the PDB and that there is no storage limit for the shared temporary tablespace that can be used by sessions connected to the PDB.

ALTER PLUGGABLE DATABASE STORAGE UNLIMITED;

Setting the Logging Attribute of a PDB

With the PDB open in restricted mode, this statement specifies the NOLOGGING attribute for the PDB:

ALTER PLUGGABLE DATABASE NOLOGGING;

Setting the Force Logging Mode of a PDB

This statement enables force logging mode for the PDB:

ALTER PLUGGABLE DATABASE ENABLE FORCE LOGGING;

Setting the Default Edition for a PDB

This example sets the default edition for the current PDB to PDB1E3.

ALTER PLUGGABLE DATABASE DEFAULT EDITION = PDB1E3;

Changing the Global Database Name of a PDB

You can change the global database name of a PDB with the ALTER PLUGGABLE DATABASE RENAME GLOBAL_NAME TO statement.

When you change the global database name of a PDB, the new global database name must be different from that of any container in the CDB.

To change the global database name of a PDB:

1. In SQL*Plus, ensure that the current container is a PDB.
2. Run an ALTER PLUGGABLE DATABASE RENAME GLOBAL_NAME TO statement.

The following example changes the global database name of the PDB to salespdb.example.com:

ALTER PLUGGABLE DATABASE RENAME GLOBAL_NAME TO salespdb.example.com;

• Close the PDB.
• Open the PDB in read/write mode.

When you change the global database name of a PDB, the PDB name is changed to the first part of the new global name, which is the part before the first period. Also, Oracle Database changes the name of the default database service for the PDB automatically. Oracle Database also changes the PDB property of all database services in the PDB to the new global name of the PDB. You must close the PDB and open it in read/write mode for Oracle Database to complete the integration of the new PDB service name into the CDB.

Oracle Net Services must be configured properly for clients to access database services. You might need to alter your Oracle Net Services configuration because of the PDB name change.

Managing Refreshable Clone PDBs

A refreshable clone PDB is a read-only clone that can periodically synchronize with its source PDB.

Refreshing a PDB

You can refresh a PDB that was created as a refreshable clone.

When you refresh a PDB manually, changes made to the source PDB since the last refresh are propagated to the PDB being refreshed. You can manually refresh a PDB that is configured for automatic refresh.

Switching Over a Refreshable Clone PDB

You can switch the roles of a source PDB and its refreshable clone PDB.

The following statement performs a switchover:

ALTER PLUGGABLE DATABASE refresh_mode FROM [email protected] SWITCHOVER;

You must not specify REFRESH MODE NONE for refresh_mode. The database link specified in the FROM clause must point to the root of the CDB in which the clone PDB resides.

After the switchover completes, the source PDB becomes the refreshable clone PDB, which can only be opened in READ ONLY mode.

To switch the roles of the source and clone PDBs:

1. In SQL*Plus or SQL Developer, log in to the source PDB.
2. Execute the ALTER PLUGGABLE DATABASE refresh_mode FROM [email protected] SWITCHOVER statement.

After the statement completes, the currently connected PDB is now the refreshable clone PDB.

• Optionally, refresh the clone PDB:

ALTER PLUGGABLE DATABASE REFRESH;

Switching Over a Refreshable Clone PDB

This example assumes that your data center contains CDBs named cdb1 and cdb2. The PDB named cdb1_pdb1 resides in cdb1. You want to create a refreshable clone of this PDB in cdb2 and name it cdb1_pdb1_ref. Your goal is to switch over cdb1_pdb1_ref so that it becomes the source PDB and cdb1_pdb1 becomes the clone PDB.

1. In SQL*Plus, connect to cdb1 as a user with administrator privileges, and then ensure sure that cdb1_pdb1 is open in read/write mode (sample output included):

CONNECT [email protected] AS SYSDBA

Enter password: *******

ALTER PLUGGABLE DATABASE ALL CLOSE;

ALTER PLUGGABLE DATABASE cdb1_pdb1 OPEN READ WRITE;

SHOW PDBS;

    CON_ID CON_NAME                       OPEN MODE  RESTRICTED

---------- ------------------------------ ---------- ----------

         2 PDB$SEED                       READ ONLY  NO

         3 CDB1_PDB1                      READ WRITE NO

• Create a common user named c##u1 (replace pwd with a user-specified password):

DROP USER c##u1 CASCADE;

CREATE USER c##u1 IDENTIFIED BY pwd;

GRANT CREATE SESSION, RESOURCE, CREATE ANY TABLE, UNLIMITED TABLESPACE TO c##u1 CONTAINER=ALL;

GRANT CREATE PLUGGABLE DATABASE TO c##u1 CONTAINER=ALL;

GRANT SYSOPER TO c##u1 CONTAINER=ALL;

• Set the container to cdb1_pdb1, and then create a table t1 to use for testing (sample output included):

ALTER SESSION SET CONTAINER = cdb1_pdb1;

CREATE TABLE t1(n1 NUMBER);

INSERT INTO t1 VALUES(1);

COMMIT;

SELECT * FROM t1;

        N1

----------

         1

• Connect to cdb2 as a user with administrator privileges, and then create the common user named c##u1 (replace pwd with a user-specified password):

CONNECT [email protected] AS SYSDBA

Enter password: *******

DROP USER c##u1 CASCADE;

CREATE USER c##u1 IDENTIFIED BY pwd;

GRANT CREATE SESSION, RESOURCE, CREATE ANY TABLE, UNLIMITED TABLESPACE TO c##u1 CONTAINER=ALL;

GRANT CREATE PLUGGABLE DATABASE TO c##u1 CONTAINER=ALL;

GRANT SYSOPER TO c##u1 CONTAINER=ALL;

Now cdb1 and cdb2 both have a common user with the same name (c##u1) and password.

• Create a database link to cdb1.

The following command specifies user c##u1, password pwd, and service name cdb1:

CREATE DATABASE LINK cdb1_datalink CONNECT TO c##u1 IDENTIFIED BY pwd USING 'cdb1';

• Create the manually refreshable PDB named cdb1_pdb1_ref.

The following statement specifies the database link cdb1_datalink and the file destination /dsk1/df:

CREATE PLUGGABLE DATABASE cdb1_pdb1_ref FROM [email protected]_datalink 

  CREATE_FILE_DEST='/dsk1/df' 

  REFRESH MODE MANUAL;

• Refresh cdb1_pdb1_ref:

ALTER SESSION SET CONTAINER = cdb1_pdb1_ref;

ALTER PLUGGABLE DATABASE REFRESH;

• Query t1 to check that the refreshable clone PDB contains the correct contents (sample output included):

ALTER PLUGGABLE DATABASE OPEN READ ONLY;

SELECT * FROM t1;

        N1

----------

         1

• Connect to cdb1 as a user with administrator privileges, and then create a database link to cdb2:

CONNECT [email protected] AS SYSDBA

Enter password: *******

CREATE DATABASE LINK cdb2_datalink CONNECT TO c##u1 IDENTIFIED BY pwd USING 'cdb2';

The preceding statement specifies user c##u1, password pwd, and service name cdb2.

1. Set the container to cdb1_pdb1, and then switch over so that cdb1_pdb1_ref is the primary PDB and the current PDB is the clone:

ALTER SESSION SET CONTAINER = cdb1_pdb1;

ALTER PLUGGABLE DATABASE 

  REFRESH MODE MANUAL 

  FROM [email protected]_datalink 

SWITCHOVER;

1. Query t1 to check that the current PDB, which is now the refreshable clone PDB, contains the correct contents (sample output included):

ALTER PLUGGABLE DATABASE OPEN READ ONLY;

SELECT * FROM t1;

        N1

----------

        1

1. Connect to cdb2 as a user with administrator privileges, set the container to the new source PDB cdb1_pdb1_ref, and then insert a new row into table t1 (sample output included):

CONNECT [email protected] AS SYSDBA

Enter password: *******

ALTER SESSION SET CONTAINER = cdb1_pdb1_ref;

SELECT * FROM t1;

        N1

----------

         1

INSERT INTO t1 VALUES(2);

COMMIT;

SELECT * FROM t1;

        N1

----------

         1

         2

1. Connect to cdb1 as a user with administrator privileges, set the container to cdb1_pdb1 (which is the new clone), refresh it, and then query t1:

CONNECT [email protected] AS SYSDBA

Enter password: *******

ALTER SESSION SET CONTAINER = cdb1_pdb1;

ALTER PLUGGABLE DATABASE CLOSE IMMEDIATE;

ALTER PLUGGABLE DATABASE REFRESH;

ALTER PLUGGABLE DATABASE OPEN READ ONLY;

SELECT * FROM t1;

        N1

----------

         1

         2

The preceding output shows that the clone cdb1_pdb1 was refreshed from the source cdb1_pdb1_ref.

Modifying the Open Mode of PDBs

You can modify the open mode of a PDB by using the ALTER PLUGGABLE DATABASE SQL statement or the SQL*Plus STARTUP command.

When a PDB is mounted, you can open it in read/write, read-only, or MIGRATE mode. You can also mount a PDB without opening it.

Open Modes of a PDB

You can view the open mode of a PDB by querying the OPEN_MODE column of the V$PDBS view.

The following table describes the possible open modes.

Mount and Open Modes

Automatic Compatibility Check

When a PDB is opened, Oracle Database checks the compatibility of the PDB with the CDB. Each compatibility violation is either of the following:

• Warning

The database records the warning in the alert log, and then opens the PDB normally without displaying a warning message.

• Error

The database displays a message when the PDB is opened stating that the PDB was altered with errors, and records the errors in the alert log. You must correct the condition that caused each error. When there are errors, the PDB is opened, but access to the PDB is limited to users with RESTRICTED SESSION privilege so that the compatibility violations can be addressed. You can view descriptions of violations by querying PDB_PLUG_IN_VIOLATIONS view.

Clauses for Changing the Open State of PDBs

To change the open mode of a PDB when the current container is the CDB root, specify the pdb_change_state clause of ALTER PLUGGABLE DATABASE.

OPEN and CLOSE Clauses

READ WRITE is the default for ALTER PLUGGABLE DATABASE OPEN unless a PDB being opened belongs to a CDB used as a physical standby database, in which case READ ONLY is the default.

When you specify PDBs to open or close, you can do the following:

• List one or more PDBs.
• Specify ALL to modify all PDBs.
• Specify ALL EXCEPT to modify all PDBs, except for the PDBs listed.

The following table describes the clauses of the ALTER PLUGGABLE DATABASE statement that modify the mode of a PDB.

ALTER PLUGGABLE DATABASE Clauses That Modify the Mode of a PDB

SERVICES Clause

You can use the services clause to specify the services that are started when a single PDB is opened.

The clause has the following variations:

• List one or more services in the services clause in the following form:

SERVICES = ('service_name' [,'service_name'] … )

• Specify ALL in the services clause to start all PDB’s services, as in the following example:

SERVICES = ALL

• Specify ALL EXCEPT in the services clause to start all PDB’s services, except for the services listed, in the following form:

SERVICES = ALL EXCEPT('service_name' [,'service_name'] … )

• Specify NONE in the services clause to start only the PDB’s default service and none of the other PDB’s services, as in the following example:

SERVICES = NONE

NONE is the default setting for the services clause. A PDB’s default service is always started, regardless of the setting for the services clause.

INSTANCES Clause

In an Oracle RAC CDB, you can use the instances clause to specify the instances on which the PDB is modified.

You can close a PDB in some instances and leave it open in others. The instances clause has the following variations:

• List one or more instances in the instances clause in the following form:

INSTANCES = ('instance_name' [,'instance_name'] … )

• Specify ALL in the instances clause to modify the PDB in all running instances, as in the following example:

INSTANCES = ALL

• Specify ALL EXCEPT in the instances clause to modify the PDB in all instances, except for the instances listed, in the following form:

INSTANCES = ALL EXCEPT('instance_name' [,'instance_name'] … )

The RELOCATE Clause

In an Oracle Real Application Clusters environment, use RELOCATE to instruct the database to reopen the PDB on a different Oracle RAC instance.

You can use the following options:

• Specify NORELOCATE, the default, to close the PDB in the current instance.
• Specify RELOCATE TO and specify an instance name to reopen the PDB in the specified instance.
• Specify RELOCATE to reopen the PDB on a different instance that is selected by Oracle Database.

Modifying the Open Mode of PDBs with ALTER PLUGGABLE DATABASE

You can modify the open mode of PDBs with the ALTER PLUGGABLE DATABASE statement with a pdb_change_state clause.

Prerequisites

To change the open mode of PDBs with the ALTER PLUGGABLE DATABASE statement, you must meet the following prerequisites:

• The current user must have one of the following administrative privileges, which must be either commonly granted or locally granted in the PDB:
  • SYSDBA, exercised using AS SYSDBA at connect time
  • SYSOPER, exercised using AS SYSOPER at connect time
  • SYSBACKUP, exercised using SYSBACKUP at connect time
  • SYSDG, exercised using AS SYSDG at connect time
• When RESTRICTED SESSION is enabled, you must specify RESTRICTED when a PDB is opened.
• In an Oracle RAC CDB, if a PDB is open in one or more Oracle RAC instances, then it can be opened in additional instances. However, the PDB must be opened in the same mode as in the instances in which it is already open. A PDB can be closed in some instances and opened on others.

To place PDBs in a target mode with the ALTER PLUGGABLE DATABASE statement, you must meet the requirements described in the following table.

Modifying the Open Mode of PDBs with ALTER PLUGGABLE DATABASE

To modify the open mode:

1. In SQL*Plus, ensure that the current container is the root.
2. Run an ALTER PLUGGABLE DATABASE statement with a pdb_change_state clause.

Changing the Open Mode of Listed PDBs

This statement changes the open mode of PDBs salespdb and hrpdb to open in read/write mode.

ALTER PLUGGABLE DATABASE salespdb, hrpdb

   OPEN READ WRITE;

This statement changes the open mode of PDB salespdb to open in read-only mode. RESTRICTED specifies that the PDB is accessible only to users with RESTRICTED SESSION privilege in the PDB.

ALTER PLUGGABLE DATABASE salespdb

   OPEN READ ONLY RESTRICTED;

This statement changes the open mode of PDB salespdb to open in migrate mode:

ALTER PLUGGABLE DATABASE salespdb

   OPEN UPGRADE;

Changing the Open Mode of All PDBs

Run the following query to display the open mode of each PDB associated with a CDB:

SELECT NAME, OPEN_MODE FROM V$PDBS WHERE CON_ID > 2;

NAME                           OPEN_MODE

------------------------------ ----------

HRPDB                          READ WRITE

SALESPDB                       MOUNTED

DWPDB                          MOUNTED

Notice that hrpdb is already in read/write mode. To change the open mode of salespdb and dwpdb to open in read/write mode, use the following statement:

ALTER PLUGGABLE DATABASE ALL

   OPEN READ WRITE;

The hrpdb PDB is not modified because it is already in open read/write mode. The statement does not return an error because two PDBs are in mounted mode and one PDB (hrpdb) is in the specified mode (read/write). Similarly, the statement does not return an error if all PDBs are in mounted mode.

However, if any PDB is in read-only mode, then the statement returns an error. To avoid an error and open all PDBs in the CDB in read/write mode, specify the FORCE keyword:

ALTER PLUGGABLE DATABASE ALL

   OPEN READ WRITE FORCE;

With the FORCE keyword included, all PDBs are opened in read/write mode, including PDBs in read-only mode.

Changing the Open Mode of All PDBs Except for Listed Ones

This statement changes the mode of all PDBs except for salespdb and hrpdb to mounted mode.

ALTER PLUGGABLE DATABASE ALL EXCEPT salespdb, hrpdb

   CLOSE IMMEDIATE;

Preserving or Discarding the Open Mode of PDBs When the CDB Restarts

You can preserve the open mode of one or more PDBs when the CDB restarts by using the ALTER PLUGGABLE DATABASE SQL statement with a pdb_save_or_discard_state clause.

You can specify which PDBs to modify in the following ways:

• List one or more PDBs.
• Specify ALL to modify all PDBs.
• Specify ALL EXCEPT to modify all PDBs, except for the PDBs listed.

For an Oracle RAC CDB, you can use the instances clause in the pdb_save_or_discard_state clause to specify the instances on which a PDB’s open mode is preserved in the following ways:

• List one or more instances in the instances clause in the following form:

INSTANCES = ('instance_name' [,'instance_name'] … )

• Specify ALL in the instances clause to modify the PDB in all running instances, as in the following example:

INSTANCES = ALL

• Specify ALL EXCEPT in the instances clause to modify the PDB in all instances, except for the instances listed, in the following form:

INSTANCES = ALL EXCEPT('instance_name' [,'instance_name'] … )

For a PDB in an Oracle RAC CDB, SAVE STATE and DISCARD STATE only affect the mode of the current instance. They do not affect the mode of other instances, even if more than one instance is specified in the instances clause.

To issue an ALTER PLUGGABLE DATABASE SQL statement with a pdb_save_or_discard_state clause, the current user must have the ALTER DATABASE privilege in the root.

You can check the saved states for the PDBs in a CDB by querying the DBA_PDB_SAVED_STATES view.

To preserve or discard a PDB’s open mode when the CDB restarts:

1. In SQL*Plus, ensure that the current container is the root.
2. Run an ALTER PLUGGABLE DATABASE statement with a pdb_save_or_discard_state clause.

The following examples either preserve or discard the open mode of one or more PDBs when the CDB restarts.

Preserving the Open Mode of a PDB When the CDB Restarts

This statement preserves the open mode of the salespdb when the CDB restarts.

ALTER PLUGGABLE DATABASE salespdb SAVE STATE;

Discarding the Open Mode of a PDB When the CDB Restarts

This statement discards the open mode of the salespdb when the CDB restarts.

ALTER PLUGGABLE DATABASE salespdb DISCARD STATE;

Preserving the Open Mode of All PDBs When the CDB Restarts

This statement preserves the open mode of all PDBs when the CDB restarts.

ALTER PLUGGABLE DATABASE ALL SAVE STATE;

Preserving the Open Mode of Listed PDBs When the CDB Restarts

This statement preserves the open mode of the salespdb and hrpdb when the CDB restarts.

ALTER PLUGGABLE DATABASE salespdb, hrpdb SAVE STATE;

Preserving the Open Mode of All PDBs Except for Listed Ones When the CDB Restarts

This statement preserves the open mode of all PDBs except for salespdb and hrpdb.

ALTER PLUGGABLE DATABASE ALL EXCEPT salespdb, hrpdb SAVE STATE;

Altering the Open Mode of a PDB Using STARTUP and SHUTDOWN

When the current container is the root, the STARTUP PLUGGABLE DATABASE command can open a single PDB.

Use the following options of the STARTUP PLUGGABLE DATABASE command to open a PDB:

• FORCE

Closes an open PDB before re-opening it in read/write mode. When this option is specified, no other options are allowed.

• RESTRICT

Enables only users with the RESTRICTED SESSION system privilege in the PDB to access the PDB.

If neither OPEN READ WRITE nor OPEN READ ONLY is specified, then the PDB is opened in read-only mode when the CDB to which it belongs is a physical standby database. Otherwise, the PDB is opened in read/write mode.

• OPEN open_pdb_options

Opens the PDB in either read/write mode or read-only mode. You can specify OPEN READ WRITE or OPEN READ ONLY. When you specify OPEN without any other options, READ WRITE is the default.

In addition, to place PDBs in a target mode with the STARTUP PLUGGABLE DATABASE command, you must meet the requirements described in the following table.

Modifying the Open Mode of a PDB with STARTUP PLUGGABLE DATABASE

Starting Up a PDB Using the STARTUP Command

When the current container is a PDB, the SQL*Plus STARTUP command opens the PDB.

Use the following options of the STARTUP command to open a PDB:

• FORCE

Closes an open PDB before re-opening it in read/write mode. When this option is specified, no other options are allowed.

• RESTRICT

Enables only users with the RESTRICTED SESSION system privilege in the PDB to access the PDB.

If neither OPEN READ WRITE nor OPEN READ ONLY is specified and RESTRICT is specified, then the PDB is opened in read-only mode when the CDB to which it belongs is a physical standby database. Otherwise, the PDB is opened in read/write mode.

• OPEN open_pdb_options

Opens the PDB in either read/write mode or read-only mode. Specify OPEN READ WRITE or OPEN READ ONLY. When RESTRICT is not specified, READ WRITE is always the default.

To modify a PDB with the STARTUP command:

1. In SQL*Plus, ensure that the current container is a PDB.
2. Run the STARTUP command.

Opening a PDB in Read/Write Mode with the STARTUP Command

STARTUP OPEN

Opening a PDB in Read-Only Mode with the STARTUP Command

STARTUP OPEN READ ONLY

Opening a PDB in Read-Only Restricted Mode with the STARTUP Command

STARTUP RESTRICT OPEN READ ONLY

Opening a PDB in Read/Write Mode with the STARTUP Command and the FORCE Option

This example assumes that the PDB is currently open. The FORCE option closes the PDB and then opens it in the read/write mode.

STARTUP FORCE

Modifying the Open Mode of PDBs with the SQL*Plus STARTUP Command

You can use the STARTUP PLUGGABLE DATABASE command to open a single PDB.

To modify a PDB with the STARTUP PLUGGABLE DATABASE command:

1. In SQL*Plus, ensure that the current container is the root.
2. Run the STARTUP PLUGGABLE DATABASE command.

Opening a PDB in Read/Write Mode with the STARTUP Command

STARTUP PLUGGABLE DATABASE hrpdb OPEN

Opening a PDB in Read/Write Restricted Mode with the STARTUP Command

STARTUP PLUGGABLE DATABASE hrpdb RESTRICT

Opening a PDB in Read-Only Restricted Mode with the STARTUP Command

STARTUP PLUGGABLE DATABASE hrpdb OPEN READ ONLY RESTRICT

Opening a PDB in Read-Only Mode with the STARTUP Command

STARTUP PLUGGABLE DATABASE hrpdb OPEN READ ONLY

Opening a PDB in Read/Write Mode with the STARTUP Command and the FORCE Option

This example assumes that the hrpdb PDB is currently open. The FORCE option closes the PDB and then opens it in the read/write mode.

STARTUP PLUGGABLE DATABASE hrpdb FORCE

Shutting Down a PDB Using the SHUTDOWN Command

When the current container is a PDB, the SQL*Plus SHUTDOWN command closes the PDB.

After the SHUTDOWN command is issued on a PDB successfully, it is in mounted mode.

The following SHUTDOWN modes are possible:

• When you specify SHUTDOWN only, then the PDB is shut down with the normal mode.
• When you specify SHUTDOWN IMMEDIATE, the PDB is shut down with the immediate mode.
• When you specify SHUTDOWN ABORT, the PDB is forcefully closed.

For a single-instance CDB, PDB media recovery is required when you specify SHUTDOWN ABORT. For an Oracle Real Application Clusters (Oracle RAC) CDB, PDB media recovery is required if the SHUTDOWN ABORT command closes the last open instance.

To modify a PDB with the SHUTDOWN command:

1. In SQL*Plus, ensure that the current container is a PDB.
2. Run the SHUTDOWN command.

Closing a PDB with the SHUTDOWN IMMEDIATE Command

SHUTDOWN IMMEDIATE

Starting and Stopping PDBs in Oracle RAC

Administering a pluggable database (PDB) involves a small subset of the tasks required to administer a non-CDB.

Administering an Oracle RAC-based multitenant container database (CDB) is similar to administering a non-CDB. The differences are that some administrative tasks apply to the entire CDB, some to the CDB root, and some to specific PDBs. In this subset of tasks, most are the same for a PDB and a non-CDB. There are some differences, however, such as when you modify the open mode of a PDB. Also, a PDB administrator is limited to managing a single PDB and is not affected by other PDBs in the CDB.

You manage PDBs in an Oracle RAC CDB by managing services. This is true regardless of whether the PDBs are policy managed or administrator managed. Assign one dynamic database service to each PDB to coordinate start, stop, and placement of PDBs across instances in a clustered container database.

For example, if you have a CDB called raccont with a policy-managed PDB called spark in a server pool called prod, then assign a service called plug to this database using the following command:

srvctl add service –db raccont –pdb spark –service plug –serverpool prod

The service plug is uniformly managed across all nodes in the server pool. If you want to have this service running as a singleton service in the same server pool, then use the -cardinality singleton parameter with the preceding command.

To open the PDB spark, you must start the service plug as follows:

srvctl start service -db raccont -service plug

To stop the service plug:

srvctl stop service -db raccont -service plug

The PDB spark remains open until you close the PDB using the SQL command ALTER PLUGGABLE DATABASE PDB_NAME CLOSE IMMEDIATE. You can check the status of the database using the srvctl status service command.

Because PDBs are managed using dynamic database services, typical Oracle RAC-based management practices apply. For this reason, if the service plug is in the online state when Oracle Clusterware is shut down on a server hosting this service, then the service is restored to its original state after the restart of Oracle Clusterware on this server. Thus, starting PDBs is automated as with any other Oracle RAC database.