Updated May 9, 2023
Introduction to Oracle RAC Interview Questions and Answers
When you talk about computing related to database, Oracle RAC (Real Application Clusters) provides and support software related to high availability and clustering within the Oracle environments. By using Oracle RAC, several computers can access Oracle’s Relational Database Management System simultaneously, even when using only a single database, thereby supporting clustering. The interconnect connects multiple instances among themselves, and they all work in perfect synchronization while trying to access the data. This post will study some of the Oracle RAC Interview Questions.
If you are looking for a job related to Oracle RAC, you must prepare for the 2023 Oracle RAC Interview Questions. Every interview is indeed different as per the various job profiles. Here, we have prepared the critical Oracle RAC Interview Questions and Answers, which will help you get success in your interview.
This 2023 Oracle RAC Interview Questions article will present the ten most essential and frequently used Oracle RAC interview questions. These questions are divided into two parts as follows:
Part 1 – Oracle RAC Interview Questions (Basic)
This first part covers basic Oracle RAC Interview Questions and Answers
Q1. Explain split brain?
Answer:
It is related to the miscommunication among nodes of a cluster. Those database nodes then continue processing and make relevant changes in their data blocks. If multiple instances are responsible for modifying one block, the data blocks cannot synchronize, and others will do those writes for the same block. This entire process is called the split-brain.
Q2. Explain the use of VIP and OLR?
Answer:
The alternative to a virtual IP address is called VIP. Every node of the cluster is mapped with VIP, and therefore in case of any node failure, the VIP notifies the application about the node being down, and itself switches towards the surviving node. In the absence of VIP, the application would encounter the TCP timeout. This TCP timeout would then notify a dead session due to the failure.
OLR, popularly known as Oracle Local Repository, consists of details related to the cluster and the processes related to it when the OCR is in the ASM system. The grid process takes time, and the ASM system will also be unavailable; therefore, an OCR local copy is booted and eventually stored inside OLR.
Let us move to the next Oracle RAC Interview Questions.
Q3. What do you understand by rolling upgrade?
Answer:
A rolling patch refers to the cluster binaries applied to the RAC environment’s up-and-running databases. The cluster nodes are rolled one after another where the patched node is unavailable, whereas all other instances are in the open state.
Q4. What do you understand by cache fusion?
Answer:
This is the basic Oracle RAC Interview Question asked in an interview. The combination of data blocks coming straight from remote database caches and getting shipped to the local nodes so that the requirements for a transaction such as a DDL or a DML can be fulfilled.
Q5. What are the uses of RAC?
Answer:
RAC, or Real Application Clusters, provides support for software that requires high availability and clustered environments. Other uses of RAC are:
- Detection of unwanted results or errors: RAC quickly solves every detected problem. Prior to notifying the user, the system automatically recovers from errors.
- Reliability: The RAC helps ensure that the server responsible for managing the database does not just depend on a single point of failure. In other words, it builds and provides a fault-tolerant mechanism where even if one node goes down, the entire system doesn’t go down, and the other provided sources should take its place and thereby providing reliability.
- Continuous Operations: All those planned as well as unplanned outages should not affect BAU
- Recoverability: The latest checkpoint ensures fast recovery in case of failure through the RAC system’s restoration.
Part 2 – Oracle RAC Interview Questions (Advanced)
Let us now have a look at the advanced interview questions.
Q6. Discuss OEM tools?
Answer:
There are two OEM tools: Database Control and Grid Control
Database control:
- A tool used for managing graphics in such a way that the database can make its configurations manually
- A single location manages the server pools through Oracle Clusterware, enabling centralized operation and management.
- The services related to Oracle RAC and Oracle Clusterware can be governed using a Database control tool.
Grid control:
- The system delivers centralized management level, administration, and configuration-related capabilities.
- Higher efficiency and reduction in cost for plans are also provided by Grid control.
Q7. What is the ASM Metadata backup technique?
Answer:
Md_backup is the command which can be used to take ASM metadata backup. It is also used to restore the disk group-based configurations if a storage loss for the ASM disk group is encountered.
Let us move to the next Oracle RAC Interview Questions.
Q8. Explain the use of interconnect.
Answer:
Moving data blocks from one instance to another involves using a private network, cache fusion, and utilizing interconnect to share the data dictionary and physical blocks.
Q9. The shared storage in RAC consists of some files. Name them. Also, what would be your approach to monitoring the protocol for interconnect traffic?
Answer:
These are the most asked Oracle RAC Interview Questions in an interview. Control files, Spfiles, Redolog files, and data files are in the shared storage.
Closely monitoring the database alert log during the specified period, especially when the database was first started, helps determine the protocol.
Q10. Suppose your remote nodes have some inventory, and you are tasked with identifying and verifying them. How will you do that?
Answer:
“Opatch Inventory-all_nodes” is the command that will ensure you can access the data of all the remotely located nodes by just a single node.
Conclusion:
In this post, we have read important Oracle RAC interview questions. The interviewer would be looking at your in-depth level of expertise and the number of hands-on you have with this particular tool. Before you arrive for your day, brushing up on your skills is always better. Please let us know how much you liked it, and keep following our blog.
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