OCM Oracle Multitenant Architecture 1 — Questions and Answers
Question 1: In Oracle Multitenant architecture, what does CDB stand for?
- Container Database (Correct answer)
- Consolidated Database Block
- Central Data Buffer
- Cluster Database Bundle
Correct answer: Container Database
CDB stands for Container Database, which is the top-level database that can host multiple Pluggable Databases (PDBs).
Question 2: Which component of a CDB serves as a read-only, system-supplied template for creating new PDBs?
- CDB$ROOT
- PDB$SEED (Correct answer)
- SEED$PDB
- ROOT$SEED
Correct answer: PDB$SEED
PDB$SEED is the read-only seed PDB provided by Oracle that acts as a template from which new Pluggable Databases are created.
Question 3: What is the maximum number of PDBs supported in a single Oracle 12.2+ CDB?
- 252
- 4096 (Correct answer)
- 1024
- 512
Correct answer: 4096
Oracle 12.2 and later supports up to 4096 PDBs in a single CDB, a significant expansion from the 252-PDB limit in Oracle 12.1.
Question 4: Which Oracle dynamic performance view provides real-time information about all containers (root, seed, and PDBs) in the current CDB?
- DBA_CONTAINERS
- V$DATABASE
- V$CONTAINERS (Correct answer)
- ALL_PDBS
Correct answer: V$CONTAINERS
V$CONTAINERS is the dynamic performance view that lists every container in the CDB including CDB$ROOT, PDB$SEED, and all user-created PDBs.
Question 5: To switch a DBA session from CDB$ROOT to a PDB named SALESPDB without disconnecting, which SQL command is used?
- ALTER SYSTEM SET CONTAINER = SALESPDB
- ALTER SESSION SET CONTAINER = SALESPDB (Correct answer)
- CONNECT TO SALESPDB
- USE CONTAINER SALESPDB
Correct answer: ALTER SESSION SET CONTAINER = SALESPDB
ALTER SESSION SET CONTAINER = <PDB_name> switches the current session context from the root to the specified PDB without requiring a reconnection.
Question 6: What does setting LOCAL_UNDO = TRUE at the CDB level enable in Oracle Multitenant?
- Each PDB maintains its own dedicated undo tablespace rather than sharing a CDB-level undo tablespace (Correct answer)
- Undo operations are restricted to the local RAC node
- A local undo segment is created in the SYSTEM tablespace
- Automatic undo management is enabled for temporary tablespaces
Correct answer: Each PDB maintains its own dedicated undo tablespace rather than sharing a CDB-level undo tablespace
LOCAL_UNDO = TRUE configures each PDB to own its individual undo tablespace, improving isolation and enabling PDB-level Flashback Database operations.
Question 7: When creating a new PDB using CREATE PLUGGABLE DATABASE, which clause is typically used to map source datafile paths to the new PDB's target file locations?
- DATAFILES IN
- FILE_NAME_CONVERT (Correct answer)
- TABLESPACE CONVERT
- PATH_CONVERT
Correct answer: FILE_NAME_CONVERT
FILE_NAME_CONVERT maps source datafile path patterns to target path patterns, telling Oracle where to place the new PDB's datafiles during creation or plug-in.
OCM Oracle Multitenant Architecture 1
In Oracle Multitenant architecture, what does CDB stand for?