Oracle DBA interview Preparing can be challenging, particularly the architecture interview portion. Oracle databases are complex systems and interviewers may ask a series of questions designed to assess both your knowledge and experience in dealing with them.

This blog explores some of the most frequently encountered Oracle DBA architecture interview questions from an architecture domain perspective, in order to better prepare learners for an interview and increase chances of success.

Knowledge of Oracle database architecture is vital for any Oracle DBA interview.

1. What is a database server?

A database server is a storage file that stores information in memory with various components such as a large pool, Java pool, log buffer, and many background processes.

The database server then writes back the information to the database, ensuring that it is available when requested.

2. What is the data architecture in Rack architecture?

The data architecture in Rack architecture consists of three layers: presentation, middleware, and data management.

The presentation layer is typically an application, such as a URL or desktop client, and the middleware layer is a middle-tier middleware app or web server hosting business logic.

3. Explain the variance between a standalone and rack database environment?

In a standalone environment, there is a single instance and one database, while in a rack environment, there are multiple instances and only one database, resulting in a many-to-one mapping.

4. What is the difference between dedicated and shared server connections?

In a dedicated server connection, one to one client is assigned to the server, and the request goes to the server pool.

The result is returned to the dedicated server, and the result is destroyed from the required servers. In a shared server connection, a request queue and response queue are found, and all users’ requests go to the request queue.

The connection method is shared, and at the database level, the command “select SID and server mode from new data association” will determine if the connection is dedicated.

5. What is the role of a listener in the database server architecture?

The listener is responsible for registering database services with the listener and taking the user’s details to start a shared server process for each connection, it is also responsible for returning the result to the user once the server process has acted on their request.

6. Define the memory components in the database server?

The memory components in the database server include the PGA, which is non-cognitive, and the SGA, which is a cerebral memory.

7. What are the components of the shared pool?

The shared pool has two components: library cache and data dictionary cache.

Library cache stores the past representation of all SQL queries, while data dictionary cache holds database object information.

8. How does the shared server process serve incoming requests?

A single shared server process is started to serve all incoming requests, it is handled by the PGA program, which is dedicated to specific user connections.

9. What is the function of the buffer cache in the database?

The buffer cache holds redo or return data, which is used for transactions and transaction changes. It is useful for instance recovery in case of database crashes.

10. Explain the aim of the checkpoint process in the database?

The checkpoint process updates control file and data file headers with the system chain number (S-MON), which is generated by each commit or transaction, it picks up S-MON numbers and updates them into the control and data file headers.

11. What is the purpose of the recover process in the database?

The recover process clears all in-door transactions when distributed transactions occur over remote databases.

12. What does the database Archiver do?

The Archiver process is used when a log writer writes to Radula, creating multiple re-logs.

Before writing to one of these logs, the archiver process takes a backup of the content inside the log one and stores it in the archiver catalogue.

13. What are database memory components and their functions?

The Java pool and stream pool are database components that allocate memory for various activities. The buffer cache holds redo or return data, which is used for transactions and transaction changes.

The memory components include the SGA, which is a cerebral memory, and the PGA, which is non-cognitive.

14. What are some of the data files in the database, and what do they store?

The database contains various data files, including control files, password files, archive files, backup files, alert files, and trace files.

Control files store database creation information, database SCN number, and data file location. Data files hold end user data and business data, while transaction logs log transaction details.

Password files hold database password details for remote connection. Parameter files define database parameters, which are read during startup and shutdown.

15. Define the variation between standalone and React databases in Oracle?

In a standalone environment, there is a single instance and one database, while in a React environment, there are multiple instances and only one database.

16. What distinguishes SQL Server static and dynamic listeners?

A static listener is a P-Mon process that registers database details every 60 seconds, while a dynamic listener is a P-Mon process that automatically registers database details with the listener.

A static listener may not be aware of the database status, which can lead to unsuccessful connections if the database is down. In contrast, a dynamic listener is always ready to register new databases.

17. How does dynamic registration work in SQL Server?

Dynamic registration occurs when the P1 process registers the database using the default port 1521, and if the listener is raised on a different port, the local listener parameter must be set manually.

18. How do Oracle rack one node and rack databases differ?

In rack one node, only one instance will be running on any one of the cluster nodes, while in rack databases, all the instances will be running on all nodes.

19. What is the role of a listener in SQL Server?

A listener is a process that manages connections to databases and services, allowing clients to connect to the correct database or service.

20. Why is it important to understand the differences between static and dynamic listeners in SQL Server?

Understanding the differences between static and dynamic listeners is important for proper database management and ensuring successful connections to the database.

21. What is the significance of having multiple instances in a rack database?

In a rack database, all four instances run simultaneously, providing more throughput and connectivity.

22. Explain the network concept in Oracle, and how is it ensured?

The network concept involves ensuring that two servers are pinging each other and two databases are communicating with each other using their IP addresses.

23. What is the principle of the demonstration?

The purpose of the demonstration is to change the database ID (DBID), database name, and database name together in an Oracle database.

24. What are the three demonstrations?                              

The first demonstration is about changing the DBID, database name, and DBID separately. The second demonstration is about changing the DBID and database name together.

The third demonstration is about changing the database name and DBID together.

25. What is listener registration, and how does it work in the database?

In the database, listener registration can be dynamic or static. In dynamic registration, the listener is registered when a client connects to the database.

In static registration, the listener is registered manually. One of the main parameters involved is the local listener.

Increase your learning with MCQ’s of Oracle DBA

1. Which component of a database server is similar to human memory?

a) Log buffe
b) Large pool
c) Java pool
d) Database server

2. In a standalone database environment, how many instances and databases are there?

a) One instance and one database
b) Multiple databases and one instance
c) One database and multiple instances
d) Multiple instances and multiple databases

3. In a rack database environment, how many databases can be created on a server?

a) One database
b) A limited number of databases
c) An unlimited number of databases
d) It depends on the capacity of the server

4. What are the three layers of data architecture in Rack architecture?

a) Listener, server process, and PGA
b) Presentation, middleware, and data management
c) Library cache, data dictionary cache, and large pool
d) Client, middle-tier, and back end

5. Which memory component in the database server stores the past representation of all SQL queries?

a) SGA
b) PGA
c) Library cache
d) Data dictionary cache

6. Database architecture is described as having a single database with one instance and one database?

a) Rack architecture
b) Three-tier architecture
c) Oracle Database architecture
d) Database server architecture

7. Which database components allocate memory for various activities, such as calls, Java compilers, and stream replication processes?

a) Buffer cache
b) Java pool
c) Stream pool
d) Background processes

8. What is the occupation of the buffer cache in a database?

a) Holds data for transactions and transaction changes
b) Logs transaction details
c) Writes data to data files
d) Writes redo logs to the buffer cache

9. Which process updates control file and data file headers with the system chain number (S-MON)?

a) Checkpoint
b) Recovery
c) Archiver
d) Log writer

10. What are the two modes in which a database can be installed?

a) Graphical user interface (GUI) and silent installation
b) Standalone and rack
c) Single instance and multiple instances
d) Local file system and NAS

11. How does dynamic registration occur in SQL Server?

a) When the P1 process registers the database using default port 1521
b) When the listener is raised on a different port, a local listener parameter must be set
c) Start the listener with an unknown status and dynamically register local and school listener parameters.
d) When the listener status is checked, the status shows that most of the database has been successfully registered

12. What are the four main types of databases in Oracle?

a) Standalone, service, rack one node, and rack database
b) Primary, secondary, archive, and standby
c) Master, slave, read-write, and read-only
d) Clustered, distributed, local, and remote

13. In a rack one node database, how many instances can be running on any one of the cluster nodes?

a) Three
b) Two
c) One
d) Four

14. Which file does the user recreate to point to the new database after removing the old SP file?

a) Control files
b) Show parameter file
c) Data files
d) Device files

15. What command is used to create and update the test for a new database?

a) ALTER DATABASE command
b) RTAB command
c) CREATE DATABASE command
d) STARTUP MOUNT command

Conclusion:

Be ready for Oracle DBA administration questions such as monitoring database statistics, configuring your database or managing user accounts to ensure a successful interview experience. Study up on these areas before your interview date!