63 questions · Core Administration And Cdb Pdb Architecture topic · All types, answers revealed
A DBA needs to identify which PDBs are currently using more than their allocated TEMP tablespace quota. Which view should be queried?
This view provides real-time information on temporary tablespace utilization per PDB.
Why this answer
V$TEMP_SPACE_HEADER and V$TEMPSEG_USAGE are standard, but V$PDB_TEMP_SPACE_USAGE provides the specific view for monitoring PDB-level temporary tablespace usage.
You are configuring a PDB to use Local Undo. What requirement must be met before setting the UNDO_TABLESPACE parameter?
Local undo changes require the PDB to be closed or restricted.
Why this answer
The CDB must be in local undo mode, and the PDB must be open in restricted mode or closed.
Which THREE characteristics are unique to PDBs?
Local users exist only within the PDB.
Why this answer
PDBs have their own datafiles, their own users, and their own services.
You need to ensure that the PDB$SEED template is updated with the latest patch level from the CDB. How should you proceed?
Patching the CDB home is the standard procedure; the seed is updated automatically by the upgrade scripts.
Why this answer
The PDB$SEED is read-only. To update it, you must apply the patch to the CDB home, and the seed will be automatically synchronized during the next CDB startup or via the execution of the datapatch utility.
What is the purpose of the 'Seed' PDB (PDB$SEED)?
PDB$SEED is the mandatory template for cloning.
Why this answer
PDB$SEED is the template for creating new PDBs.
You observe that a PDB is consuming excessive UNDO tablespace. You want to implement 'Local Undo' mode for the CDB. What is the consequence of this change?
Changing from shared undo to local undo requires the CDB to be in a state where all PDBs are closed.
Why this answer
Enabling Local Undo mode means each PDB manages its own undo tablespace. This is a CDB-wide setting that requires all PDBs to be closed before the CDB can be switched to this mode.
Which TWO methods can be used to copy a PDB?
CREATE PLUGGABLE DATABASE ... AS CLONE.
Why this answer
Cloning and unplugging/plugging are standard methods.
Which parameter defines the location of the PDB metadata files during a plug operation?
Helps relocate datafiles during PDB operations.
Why this answer
The file_name_convert parameter or explicit pathing is used.
Which command is used to move a PDB from one CDB to another without using Data Pump?
Unplugging generates the XML metadata for transport.
Why this answer
The unplug/plug method using an XML metadata file is the standard for PDB transport.
Which feature allows you to perform point-in-time recovery for a specific PDB without affecting others?
Supports recovery of a PDB to a specific timestamp.
Why this answer
RMAN PDB-level point-in-time recovery is supported.
Which file stores the metadata for a PDB being unplugged?
The XML file contains metadata for the PDB transport.
Why this answer
The unplug process generates an XML file to describe the PDB.
When managing local and common users in a 23ai CDB, which TWO of the following statements are correct?
Common users must be created in CDB$ROOT to be visible across PDBs.
Why this answer
Common users must be created in the root (CDB$ROOT) and local users are specific to individual PDBs.
If you want to use a PDB as a template for other PDBs, what state must the template PDB be in?
Template PDBs must be opened read-only.
Why this answer
The PDB must be open in READ ONLY mode to be used as a template.
Which THREE statements are true regarding the use of the 'ALTER PLUGGABLE DATABASE' command in a 23ai environment?
The SERVICE_NAME_CONCATE clause or set service allows PDB-specific service management.
Why this answer
The command is versatile, allowing for state changes, file management, and resource plan applications, but it cannot be used for tasks like creating the CDB itself.
What happens when you execute 'ALTER PLUGGABLE DATABASE ALL OPEN'?
The ALL clause applies to all PDBs.
Why this answer
All PDBs in the CDB are opened in READ WRITE mode.
You need to migrate a non-CDB to a PDB in an existing CDB. Which package should you use to check for compatibility issues before starting the migration?
This procedure checks if a non-CDB is compatible with the target CDB.
Why this answer
DBMS_PDB.CHECK_PLUG_COMPATIBILITY is the standard procedure for pre-migration validation.
You want to limit the amount of memory a specific PDB can consume in a CDB. Which parameter should you configure?
PDB_SGA_TARGET allows limiting memory per PDB.
Why this answer
The SGA_TARGET at the PDB level is managed via the PDB_SGA_TARGET parameter.
Which TWO tasks are required to successfully unplug a PDB?
Unplugging creates the XML manifest.
Why this answer
You must close the PDB and then execute the UNPLUG command.
Which TWO parameters are critical for PDB resource management?
Limits CPU usage per PDB.
Why this answer
PDB_SGA_TARGET and CPU_COUNT (or PDB_CPU_COUNT) control PDB resources.
Which THREE actions occur when you execute 'ALTER PLUGGABLE DATABASE PDB1 OPEN'?
Default open mode is READ WRITE.
Why this answer
The PDB state changes, triggers run, and services are started.
Which directory contains the Alert log for the CDB?
This is the standard ADR path.
Why this answer
The Automatic Diagnostic Repository (ADR) stores all CDB diagnostic information.
Which TWO security features can be applied specifically to a PDB?
Can be set per PDB.
Why this answer
Encryption and Auditing can be PDB-specific.
You are configuring a new CDB and want to ensure that PDBs use only a specific subset of the CDB's total SGA memory while allowing individual PDBs to scale up when demand is high. Which parameter should you configure to enforce this?
This parameter limits the maximum amount of SGA memory that a specific PDB can consume.
Why this answer
The SGA_TARGET parameter at the CDB level defines the total SGA, while PDB_SGA_MIN_SIZE and PDB_SGA_MAX_SIZE parameters allow for fine-grained control and resource capping within the multitenant environment.
What happens to existing sessions when you issue 'ALTER PLUGGABLE DATABASE PDB1 CLOSE'?
IMMEDIATE forces the closing of sessions.
Why this answer
By default, the command fails if sessions exist unless 'IMMEDIATE' is used.
Which THREE parameters can be set at the PDB level?
Allowed as a PDB-specific setting.
Why this answer
SGA_TARGET, UNDO_TABLESPACE, and DB_FILE_NAME_CONVERT can be PDB-specific.
Which TWO tools can be used to perform PDB point-in-time recovery?
Standard tool for PITR.
Why this answer
RMAN and SQL*Plus are used to manage PDB PITR operations.
A PDB is in 'READ WRITE' mode. You need to perform a maintenance task that requires the PDB to be in 'RESTRICTED' mode. Which command achieves this?
The correct sequence is to close the PDB first, then reopen it with the RESTRICTED privilege.
Why this answer
To move a PDB into restricted mode, you must use ALTER PLUGGABLE DATABASE ... CLOSE followed by OPEN RESTRICTED.
You need to ensure that the PDB name is unique in your network. Which parameter should you check?
Must be unique for each database in a Data Guard configuration.
Why this answer
DB_UNIQUE_NAME must be unique across the CDB infrastructure.
What is the default behavior when shutting down a CDB instance?
PDBs are closed automatically during CDB shutdown.
Why this answer
The SHUTDOWN command closes all PDBs before the CDB.
Which command is used to display the current container you are connected to?
Displays the current container context.
Why this answer
SHOW CON_NAME shows the current container name in SQL*Plus.
Which THREE steps are involved in upgrading a PDB?
Verify no issues persist.
Why this answer
Run the upgrade script, compile invalid objects, and check for errors.
How can you verify if a PDB is encrypted?
This view shows the wallet and encryption status.
Why this answer
Querying DBA_PDB_KE_STATE or checking V$ENCRYPTION_WALLET is the standard method.
You need to capture PDB performance data. Which feature allows you to capture an AWR snapshot for a specific PDB?
This procedure supports a container ID parameter.
Why this answer
DBMS_WORKLOAD_REPOSITORY.CREATE_SNAPSHOT is used for AWR snapshots at the container level.
Which THREE features are specific to the Multitenant architecture and distinguish a CDB from a non-CDB?
PDBs share the instance processes of the CDB.
Why this answer
Multitenant architecture relies on shared background processes, centralized data dictionary views (CDB_ views), and the ability to plug and unplug databases.
What is the default state of a PDB after creating it using the CREATE PLUGGABLE DATABASE command?
The default state is MOUNTED.
Why this answer
By default, a new PDB is created in MOUNTED state.
Which TWO actions are required when performing a 'Unplug and Plug' operation of a PDB between two different CDBs to ensure data integrity?
The XML file is required to describe the PDB's datafiles for the subsequent plug operation.
Why this answer
To safely move a PDB, the database must be in a consistent state (closed) and the metadata XML file must be generated to describe the PDB structures.
Which TWO views are essential for monitoring PDB-specific memory usage?
Tracks memory per PDB.
Why this answer
V$PDB_MEMORY and V$RESOURCE_LIMIT allow tracking PDB memory consumption.
Which initialization parameter determines the maximum number of PDBs allowed in a CDB?
This parameter limits the number of PDBs.
Why this answer
MAX_PDB_CONTAINERS defines the hard limit for PDBs in a CDB.
You need to migrate a non-CDB database to a PDB in a 23ai CDB. Which utility is the recommended tool to assess compatibility before migration?
This function performs a series of checks on the source database to ensure it can be plugged into the target CDB.
Why this answer
DBMS_PDB.CHECK_PLUG_COMPATIBILITY is the standard PL/SQL procedure to identify potential issues before plugging a non-CDB into a CDB.
What is the standard tool to manage CDB/PDB configuration in 23ai?
Standard CLI tool for DB administration.
Why this answer
SQL*Plus or SQLcl are the standard interfaces for managing CDBs.
Which view provides information about the open status of all PDBs in a CDB?
V$PDBS is the correct dynamic performance view for PDB status.
Why this answer
V$PDBS provides the current status of each PDB in the container database.
An administrator needs to perform maintenance on a specific PDB while keeping the rest of the CDB and other PDBs fully operational. What is the correct state to set the PDB to?
The MOUNTED state allows PDB maintenance operations while the CDB remains open.
Why this answer
Setting a PDB to MOUNTED state allows administrators to perform administrative tasks, such as renaming datafiles or performing point-in-time recovery, without opening the PDB for user access.
You need to monitor wait events for a specific PDB. Which view is most appropriate?
Contains CON_ID to filter by container.
Why this answer
V$SESSION filtered by CON_ID allows viewing PDB-specific sessions.
Which TWO views are used to check for plug-in compatibility?
Shows version compatibility.
Why this answer
PDB_PLUG_IN_VIOLATIONS and DBMS_PDB.CHECK_PLUG_COMPATIBILITY are standard.
You are creating a new PDB from an existing one using the CREATE PLUGGABLE DATABASE command. Which clause must you include to ensure the new PDB has a different name and storage location?
This clause is mandatory when cloning a PDB to specify the source and destination file paths.
Why this answer
The CREATE PLUGGABLE DATABASE statement requires the file_name_convert clause to define the directory structure for the new PDB datafiles.
Which THREE pieces of information are displayed when you run 'SHOW PDBS'?
The timestamp is included.
Why this answer
It shows the PDB name, status, and creation time.
Which TWO actions should be performed before dropping a PDB?
Must be closed to drop.
Why this answer
Close the PDB and ensure no active sessions remain.
Which component is responsible for managing background processes across all containers in a CDB?
Processes are managed by the CDB level instance.
Why this answer
The instance (CDB root) manages background processes for all containers.
You need to create a PDB from a remote PDB. Which clause must be included in the CREATE PLUGGABLE DATABASE command?
Required for remote PDB cloning.
Why this answer
The FROM clause with a database link is required for remote cloning.
Which THREE components are shared between a CDB and its PDBs?
Processes are shared at the instance level.
Why this answer
The SGA, background processes, and redo logs are shared.
When performing a 'Refreshable PDB Switchover', what is the state of the source PDB?
The source becomes a refreshable PDB and stays in READ ONLY mode.
Why this answer
During a switchover, the source PDB is converted to a refreshable PDB.
Which THREE types of information are contained in the PDB XML metadata file?
Paths for the PDB files.
Why this answer
It contains file paths, GUIDs, and character set information.
When using 'Snapshot Carousel', how many snapshots can a single PDB retain?
This parameter governs the snapshot limit.
Why this answer
The number is managed by the MAX_PDB_SNAPSHOTS parameter.
What is the purpose of the 'CDB_ROOT'?
The root is the central management container.
Why this answer
The CDB root manages system-wide objects and metadata.
When a PDB is in 'RESTRICTED' mode, which sessions are allowed?
This privilege is required to access restricted PDBs.
Why this answer
Only users with RESTRICTED SESSION privilege are allowed.
You are configuring a new CDB and want to ensure that PDBs use a common set of initialization parameters while allowing for specific overrides. Which parameter must be configured at the CDB level to allow local PDB parameter overrides?
PDB_SPFILE is essential for managing local PDB initialization parameters.
Why this answer
The PDB_SPFILE parameter in the CDB root allows managing individual PDB spfiles.
Which view displays the PDBs that are currently open in the CDB?
V$PDBS lists all PDBs and their open state.
Why this answer
V$PDBS shows the status of all PDBs in the instance.
You are configuring a PDB. What happens to the PDB if you drop the CDB?
PDBs cannot exist outside a CDB.
Why this answer
All PDBs are automatically removed when the CDB is dropped.
Which command allows you to change the state of a PDB to READ ONLY?
Correct syntax for read-only mode.
Why this answer
ALTER PLUGGABLE DATABASE [PDB_NAME] OPEN READ ONLY is the correct syntax.
You are migrating a non-CDB database to a PDB in a 23ai CDB using the remote cloning method. Which condition must be met for the non-CDB to be successfully plugged in?
A non-CDB must be opened READ ONLY to allow the CDB to perform the metadata copy.
Why this answer
When plugging in a non-CDB, it must be opened in READ ONLY mode to ensure consistency during the cloning process, and the non-CDB must be at a version compatible with the CDB.
Which privilege is required to perform a PDB unplug operation?
Required for container management operations.
Why this answer
SYSDBA or SYSOPER at the CDB root is required.
What is the primary benefit of using a 'Proxy PDB'?
Proxy PDBs provide local access to remote PDB objects.
Why this answer
A Proxy PDB allows access to a PDB in a remote CDB.
Which dictionary view tracks the PDB creation time?
Contains PDB metadata including creation time.
Why this answer
CDB_PDBS contains the creation time of all PDBs in the CDB.
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