600+ Oracle Interview Questions and Answers

You can measure 4 liters by following these steps:

• Fill the 5 liters container completely

• Pour the 5 liters into the 3 liters container, leaving 2 liters in the 5 liters container

• Empty the 3 liters container

• Pour the remaining 2 liters from the 5 liters container into the 3 liters container

• Fill the 5 liters container again

• Pour 1 liter from the 5 liters container into the 3 liters container, which now has 3 liters

• The 5 liters container now has 4 liters

Return the index of the vector with the longest length palindrome

• Iterate through each string in the vector

• Check if the string is a palindrome

• Track the index of the longest palindrome string

Algorithm to find median in a stream of n numbers

• Sort the list and find the middle element for odd n

• For even n, find the average of middle two elements

• Use a min-heap and max-heap to maintain the smaller and larger half of the stream respectively

• Insert new elements into the appropriate heap and balance the heaps to ensure median is always at the top

A linked list is a linear data structure where each element is a separate object linked together by pointers.

• Linked list is used to implement stacks, queues, and hash tables.

• It is used in computer memory allocation.

• It is used in image processing to represent pixels.

• It is used in music player to create a playlist.

• It is used in web browsers to store the history of visited web pages.

The result of adding two binary numbers in a 64-bit and a 32-bit operating system will differ due to the different number of bits used for calculations.

• In a 64-bit operating system, the result will be more accurate and can handle larger numbers compared to a 32-bit system.

• Overflow may occur in a 32-bit system when adding large binary numbers, leading to incorrect results.

• Example: Adding 1111 (15 in decimal) and 1111 (15 in decimal) in a 32-bit system may result in overflow an...read more

The algorithm for the upcoming semester project involves developing an application.

• Identify the requirements and objectives of the project

• Design the application architecture and user interface

• Implement the necessary algorithms and data structures

• Test and debug the application

• Optimize the performance and efficiency of the code

• Document the project for future reference

Primitives are basic data types in Java while wrapper classes are objects that wrap around primitives.

• Primitives are faster and take less memory than wrapper classes.

• Wrapper classes provide additional functionality like conversion to and from strings.

• Primitives are passed by value while wrapper classes are passed by reference.

• Examples of primitives include int, boolean, and double while examples of wrapper classes include Integer, Boolean, and Double.

std::list from the C++ Standard Template Library (STL) allows insertion and removal of data from anywhere.

• std::list is a doubly linked list implementation in STL

• Elements can be inserted or removed from anywhere in the list efficiently

• Example: std::list<int> myList; myList.insert(myList.begin(), 5); myList.erase(myList.begin());

Excel rules are formula-based while OPA rules are natural language-based.

• Excel rules are written using formulas and functions, while OPA rules are written in natural language using if-then statements.

• Excel rules are limited to the capabilities of the Excel program, while OPA rules can be more complex and flexible.

• OPA rules can be easily updated and maintained by non-technical users, while Excel rules may require technical expertise.

• Excel rules are typically used for simple ca...read more

Use backtracking to find all combinations of numbers in an array that sum up to a given number.

• Start by sorting the array in non-decreasing order to easily identify combinations.

• Use backtracking to recursively find all combinations that sum up to the target number.

• Keep track of the current combination and the remaining sum as you traverse the array.

• Add the current combination to the result when the sum equals the target number.

Code to find the middle element of a linked list

• Traverse the linked list with two pointers, one moving twice as fast as the other

• When the fast pointer reaches the end, the slow pointer will be at the middle element

• If the linked list has even number of elements, return the second middle element

Code to count the number of times '1' occurs from 1 to 999999

• Loop through all numbers from 1 to 999999

• Convert each number to a string and count the number of '1's in it

• Add the count to a running total

• Return the total count

The code prints the transpose of a given matrix.

• Iterate through each row and column of the matrix.

• Swap the elements at the current row and column with the elements at the current column and row.

• Print the transposed matrix.

Virtual functions in C++ allow a function to be overridden in a derived class, enabling polymorphic behavior.

• Virtual functions are declared in a base class with the 'virtual' keyword.

• They are overridden in derived classes to provide specific implementations.

• Virtual functions enable polymorphism, allowing objects of different derived classes to be treated as objects of the base class.

• Example: class Shape { virtual void draw() { ... } }; class Circle : public Shape { void draw(...read more

Around 600 flights are handled by Bangalore airport on a daily basis.

• Bangalore airport is one of the busiest airports in India

• It handles both domestic and international flights

• On average, there are around 25-30 flights per hour

• The number of flights may vary depending on the day of the week and time of the year

Form an 8-digit number in the pattern 312132 with digits 1, 2, 3, and 4.

• The pattern is 3 digits between 3, 2 digits between 2, and 1 digit between 1.

• The number can start with any digit.

• The remaining digits can be arranged in any order.

The OSI model has 7 layers that define how data is transmitted over a network.

• Layer 1: Physical layer - deals with the physical aspects of transmitting data

• Layer 2: Data link layer - responsible for error-free transfer of data between nodes

• Layer 3: Network layer - handles routing of data between different networks

• Layer 4: Transport layer - ensures reliable delivery of data between applications

• Layer 5: Session layer - establishes and manages connections between applications

• Lay...read more

DELETE removes specific rows from a table, while TRUNCATE removes all rows and resets auto-increment values.

• DELETE is a DML command, while TRUNCATE is a DDL command.

• DELETE can be rolled back, while TRUNCATE cannot be rolled back.

• DELETE triggers ON DELETE triggers, while TRUNCATE does not trigger any triggers.

• DELETE is slower as it logs individual row deletions, while TRUNCATE is faster as it logs the deallocation of the data pages.

• Example: DELETE FROM table_name WHERE conditi...read more

Find the common ancestor of two given nodes in a tree

• Traverse the tree from the root node

• Check if both nodes are on the same side of the current node

• If not, return the current node as the common ancestor

• If yes, continue traversing down that side of the tree

Data structures are ways of organizing and storing data in a computer so that it can be accessed and used efficiently.

• Data structures can be linear or non-linear

• Examples of linear data structures include arrays, linked lists, and stacks

• Examples of non-linear data structures include trees and graphs

• Choosing the right data structure is important for optimizing performance and memory usage

FTP transfers files using a client-server model with separate control and data connections. Multiple sockets are used for one file transfer.

• FTP works on a client-server model where the client initiates a connection to the server.

• Two separate connections are established for file transfer - a control connection for commands and a data connection for actual file transfer.

• The control connection is used to send commands like login, change directory, etc.

• The data connection is used...read more

The time complexity of 8 queens algorithm is O(n!).

• The algorithm checks all possible permutations of the queens on the board.

• The number of permutations is n! where n is the number of queens.

• For 8 queens, there are 8! = 40,320 possible permutations.

• The algorithm has to check each permutation to find a valid solution.

• Therefore, the time complexity is O(n!).

Arrange 4 coins to make maximum number of triangles

• Place 3 coins in a triangle formation and the fourth coin in the center to form 4 triangles

• Place 2 coins on top of each other and the other 2 coins on either side to form 2 triangles

• Place 2 coins in a line and the other 2 coins on either side to form 2 triangles

TCP/IP model has four layers: Application, Transport, Internet, and Network Access.

• Application layer handles high-level protocols like HTTP, FTP, SMTP, etc.

• Transport layer provides end-to-end communication between hosts using TCP or UDP protocols.

• Internet layer handles the routing of data packets between networks using IP protocol.

• Network Access layer deals with the physical transmission of data over the network.

• Examples of protocols at each layer: HTTP (Application), TCP (Tr...read more

Yes, it is possible to import the same class or package twice in Java, but it will not cause any issues during runtime.

• Importing the same class or package multiple times in Java will not result in any errors or conflicts.

• The Java compiler will simply ignore duplicate imports and only include the class or package once in the compiled code.

• This behavior helps in avoiding unnecessary redundancy and keeps the code clean and concise.

Given 2 arrays with n and n-1 elements, find the unique element in the larger array.

• Loop through the larger array and check if each element is present in the smaller array.

• If an element is not present in the smaller array, it is the unique element.

• Return the unique element.

• Example: arr1 = ['a', 'b', 'c', 'd'], arr2 = ['a', 'b', 'c'], unique element = 'd'

My favorite program is Visual Studio Code because of its user-friendly interface and extensive plugin library.

• User-friendly interface with customizable settings

• Extensive plugin library for various programming languages and tools

• Integrated terminal and debugging features

• Supports Git version control

• Frequent updates and improvements

• Free and open-source

• Examples: Python, JavaScript, HTML/CSS, Git

Arrange 10 coins in 4 rows of 4 coins each.

• Place 4 coins in a row and keep the remaining 6 aside.

• Place 3 coins from the remaining 6 in the next row and keep the remaining 3 aside.

• Place 2 coins from the remaining 3 in the third row and keep the remaining 1 aside.

• Place the last coin in the fourth row along with the remaining 1 coin from step 3.

• The final arrangement will have 4 rows with 4 coins each.

String Buffer and String Builder are both used to manipulate strings, but the former is synchronized while the latter is not.

• String Buffer is thread-safe while String Builder is not

• String Builder is faster than String Buffer

• String Builder is preferred when thread safety is not a concern

• String Buffer is used when multiple threads are involved in manipulating the same string

• Both classes have similar methods for appending, inserting, and deleting characters

The amount of equipment needed to make one access door varies depending on the specific requirements and design of the door.

• The type of access door (e.g. metal, wood, glass) will determine the necessary equipment.

• Common equipment includes measuring tools, cutting tools (e.g. saw, drill), hinges, screws, and a door handle.

• Additional equipment may be needed for specialized features such as locks, insulation, or decorative elements.

• The quantity of equipment required will also de...read more

Count the frequency of each alphabet in a string.

• Iterate through the string and count the occurrence of each alphabet using a dictionary or array.

• Convert the string to lowercase or uppercase to avoid case sensitivity.

• Exclude non-alphabetic characters using regular expressions.

• Consider using built-in functions or libraries for efficiency.

• Handle edge cases such as empty strings or strings with no alphabetic characters.

The emerging technology that excites me the most is Artificial Intelligence.

• AI has the potential to revolutionize various industries such as healthcare, finance, and transportation.

• One use case of AI is in medical diagnosis, where it can analyze large amounts of patient data to identify patterns and make accurate predictions.

• Another use case is in autonomous vehicles, where AI can help improve safety and efficiency on the roads.

• AI can also be used in fraud detection and preve...read more

Difference between @Service and @Component

• Both are used for component scanning in Spring

• @Service is used for service layer classes

• @Component is used for general purpose beans

• Service layer classes contain business logic

• Examples of @Service: UserService, ProductService

• Examples of @Component: DAO, Utility classes

TCP/IP model is a protocol used for data communication. It consists of four layers: application, transport, internet, and network access.

• Data is sent from the application layer to the transport layer where it is divided into segments.

• The internet layer adds IP addresses to the segments and sends them to the network access layer.

• The network access layer adds physical addresses and sends the data over the network.

• The process is reversed at the receiving end.

• Examples of TCP/IP p...read more

I would use a relational database like MySQL for the Parking lot as it provides structured data storage and supports complex queries.

• Relational databases like MySQL offer structured data storage for parking lot information

• Supports complex queries for managing parking lot data efficiently

• Ability to handle large amounts of data and transactions

• Provides data integrity and security features

• Can easily integrate with other systems and applications

Classful addressing uses fixed length subnet masks, while classless addressing allows for variable length subnet masks.

• Classful addressing divides IP addresses into classes (A, B, C, D, E) with fixed subnet masks.

• Classless addressing allows for more efficient use of IP addresses by using variable length subnet masks.

• Classful addressing can lead to wastage of IP addresses, while classless addressing is more flexible and scalable.

• Classful addressing is outdated and not commonly...read more

Transactions in a bank involve the movement of funds between accounts or the exchange of currency.

• Transactions can be initiated by customers or by the bank itself

• Common types of transactions include deposits, withdrawals, transfers, and loans

• Transactions are recorded in the bank's ledger and may be subject to fees or interest

• Electronic transactions have become increasingly popular, such as online banking and mobile payments

String is immutable while StringBuffer is mutable.

• String objects are constant and cannot be changed once created.

• StringBuffer objects are mutable and can be modified.

• StringBuffer is thread-safe while String is not.

• StringBuffer has methods to append, insert, and delete while String does not.

• Example: String str = "hello"; StringBuffer sb = new StringBuffer("world");

• str.concat("world"); // returns a new string "helloworld"

• sb.append("hello"); // modifies the existing StringBuffer...read more

MVC components include Model, View, and Controller for organizing code in a web application.

• Model: Represents the data and business logic of the application.

• View: Represents the UI and presentation layer of the application.

• Controller: Acts as an intermediary between Model and View, handling user input and updating the Model accordingly.

• Example: In a web application, a user interacts with the View (UI), which sends requests to the Controller. The Controller processes the reque...read more

SQL query to retrieve the Nth highest salary from a database

• Use the ORDER BY clause to sort salaries in descending order

• Use the LIMIT clause to retrieve the Nth highest salary

• Consider handling cases where there might be ties for the Nth highest salary

Strings are immutable in Java to ensure thread safety and prevent unintended changes.

• Immutable objects are safer to use in multi-threaded environments

• String pool optimization is possible because of immutability

• StringBuffer and StringBuilder classes are available for mutable string operations

Iterate through the linked list and store the strings in a stack. Then pop the strings from the stack to print them in reverse order.

• Create a stack to store the strings as you iterate through the linked list.

• Pop the strings from the stack to print them in reverse order.

• Example: If the linked list contains |ram|->|manish|->|mohan|->|rajesh|->|mar|->|nahom|->|tips|->null, the output should be tips, nahom, mar, rajesh, mohan, manish, ram.

TCP is a reliable, connection-oriented protocol. UDP is a connectionless protocol. TLS is a secure protocol for data encryption.

• TCP ensures reliable data transmission by establishing a connection between sender and receiver.

• UDP is faster but less reliable as it does not establish a connection before sending data.

• TLS provides secure communication by encrypting data and verifying the identity of the communicating parties.

• TCP and UDP are transport layer protocols while TLS is a ...read more

Program to return list of .tst files in given directory and subdirectories

• Use recursion to traverse through all directories and subdirectories

• Check if each file has .tst extension and add to list if true

• Use built-in functions like os.listdir() and os.path.splitext() in Python

Program to concatenate Zig Zag string from a row using Java String Operations.

• Use StringBuilder to efficiently concatenate strings

• Use loops to traverse the rows and columns of the zig zag pattern

• Use conditional statements to determine the direction of traversal

Find the missing number from 1 million random numbers.

• Calculate the sum of all numbers from 1 to 1 million using the formula n(n+1)/2

• Calculate the sum of all the given numbers

• Subtract the sum of given numbers from the sum of all numbers to get the missing number

There are four types of HTTP requests in Spring Boot: GET, POST, PUT, and DELETE.

• GET: used to retrieve data from a server

• POST: used to submit data to a server

• PUT: used to update existing data on a server

• DELETE: used to delete data from a server

• These requests are handled by the @RequestMapping annotation in Spring Boot

Spring Boot annotations are used to simplify the development process. Some common annotations are @SpringBootApplication, @RestController, @Autowired, @GetMapping, @PostMapping, @Service, @Repository, @Component, etc.

• The @SpringBootApplication annotation is used to mark the main class of the application.

• The @RestController annotation is used to mark a class as a RESTful controller.

• The @Autowired annotation is used to inject dependencies.

• The @GetMapping and @PostMapping annota...read more

The path followed to connect to a given IP of another system involves multiple steps and protocols.

• First, the system resolves the domain name to an IP address using DNS.

• Then, the system establishes a TCP connection to the destination IP.

• Next, data is exchanged between the systems using the TCP protocol.

• Finally, the connection is terminated once the data transfer is complete.

Hashmap is a data structure that stores key-value pairs and provides constant time complexity for basic operations.

• Hashmap uses hashing to store and retrieve values based on their keys.

• Concurrent Hashmap is a thread-safe version of Hashmap.

• Middle node of LinkedList can be found using two pointers, one moving at twice the speed of the other.

• JVM is a virtual machine that executes Java bytecode.

• JRE is a runtime environment that provides libraries and tools for executing Java pro...read more

Print Pythagorean triplets within a given range.

• Iterate through all possible combinations of a, b, and c within the given range

• Check if a^2 + b^2 = c^2 for each combination

• Print the triplets that satisfy the Pythagorean theorem

Marker interfaces in Java are interfaces with no methods, used to mark classes for special treatment.

• Marker interfaces have no methods, they simply mark a class as having a certain capability or characteristic.

• Examples of marker interfaces in Java include Serializable, Cloneable, and Remote.

• Classes implementing marker interfaces can be treated differently by the JVM or other components based on the interface they implement.

What-if analysis in Oracle Policy Automation is a tool that allows users to simulate different scenarios and evaluate their impact on policy outcomes.

• Users can create hypothetical scenarios by changing input values and assumptions

• The tool then calculates the impact of these changes on policy outcomes

• This helps users make informed decisions and identify potential risks and opportunities

• For example, a user can simulate the impact of changing eligibility criteria on the number o...read more

String is immutable because it cannot be changed once created.

• Immutable objects are safer to use in multi-threaded environments.

• String pool in Java is possible because of immutability.

• StringBuffer and StringBuilder are mutable alternatives to String.

Remove duplicate elements in an array.

• Create a new empty array.

• Loop through the original array and check if the element already exists in the new array.

• If it doesn't exist, add it to the new array.

• Return the new array without duplicates.

Implementing caching mechanisms and optimizing authentication processes can help reduce the impact of authentication requests on the authentication platform.

• Implement caching mechanisms to store authentication tokens locally and reduce the need for frequent requests to the authentication platform.

• Optimize authentication processes by using efficient algorithms and data structures to quickly verify user credentials.

• Implement rate limiting to prevent excessive authentication req...read more

Java api implementation approach and front-end connection.

• Java api implementation involves creating classes and methods to interact with the api

• The front-end can connect to the api using HTTP requests and JSON data

• Frameworks like Spring can simplify the implementation process

• API documentation is crucial for understanding how to use the api

Find maximum sum of substring and merge two arrays without extra space.

• Use Kadane's algorithm to find maximum sum of substring in an array.

• To merge two arrays without extra space, use two pointers approach.

• Example: Input arrays [1, 2, -3, 4, 5] and [6, 7, 8], output merged array [1, 2, -3, 4, 5, 6, 7, 8].

Implementation of Linked List with add, display, insert at end and delete operations.

• Create a Node class with data and next pointer

• Create a LinkedList class with head pointer

• Add method to add a new node at the end of the list

• Display method to print all nodes in the list

• Insert at end method to insert a new node at the end of the list

• Delete method to delete a node from the list

The strategy for moving from one cloud to another involves careful planning and execution, with a focus on minimizing downtime and ensuring data security.

• Assess the current cloud environment and identify the reasons for the move

• Evaluate the target cloud provider and ensure compatibility with existing systems

• Develop a migration plan that includes timelines, resource allocation, and risk management

• Test the migration plan in a non-production environment before executing it

• Commun...read more

The various types of inheritance in Object-Oriented Programming include single, multiple, multilevel, hierarchical, and hybrid inheritance.

• Single inheritance: a class can inherit from only one base class.

• Multiple inheritance: a class can inherit from multiple base classes.

• Multilevel inheritance: a class can inherit from a class which is also derived from another class.

• Hierarchical inheritance: multiple classes can inherit from a single base class.

• Hybrid inheritance: a combina...read more

Static typing requires variable types to be declared at compile time, while dynamic typing allows types to be determined at runtime.

• Static typing requires explicit declaration of variable types, while dynamic typing infers types at runtime.

• Static typing helps catch errors at compile time, while dynamic typing may lead to runtime errors.

• Python is dynamically typed, but can be used with type hints for static type checking.

• Example of static typing: int x = 5

• Example of dynamic ty...read more

Static binding is resolved at compile time while dynamic binding is resolved at runtime in Java.

• Static binding is also known as early binding.

• Dynamic binding is also known as late binding.

• Example of static binding: method overloading.

• Example of dynamic binding: method overriding.

Finding common elements in two sorted linked lists.

• Traverse both lists simultaneously using two pointers.

• Compare the values of the nodes pointed by the two pointers.

• If they are equal, add the value to the result list and move both pointers.

• If not, move the pointer pointing to the smaller value.

• Repeat until one of the lists is fully traversed.

Count the number of palindromes in a given string.

• A palindrome is a word, phrase, number, or other sequence of characters that reads the same forward and backward.

• Iterate through the string and check if each substring is a palindrome.

• Use two pointers, one at the beginning and one at the end of the substring, and move them towards each other until they meet in the middle.

• If the substring is a palindrome, increment the count.

• Consider both even and odd length palindromes.

Find the fifth largest element in a linked list

• Traverse the linked list and store the elements in an array

• Sort the array in descending order

• Return the fifth element in the sorted array

Explanation of differences between List and ArrayList, HashMap behavior with same key, Spring boot beans, Profile annotation in Spring, database configurations in pom.xml, and data structures.

• List is an interface while ArrayList is a class that implements List interface

• HashMap replaces the old value with the new value if the same key is added

• Spring boot beans can be avoided by using @Lazy annotation

• Profile annotation in Spring allows defining different configurations for diff...read more

PL/SQL is a procedural language designed specifically for the Oracle Database management system.

• PL/SQL is used to create stored procedures, functions, triggers, and packages in Oracle databases.

• It is a block-structured language that allows developers to write code in logical blocks.

• PL/SQL supports data types such as VARCHAR2, NUMBER, DATE, BOOLEAN, etc.

• It also supports control structures like IF-THEN-ELSE, FOR LOOP, WHILE LOOP, etc.

• PL/SQL can be used to manipulate data in Ora...read more

Static variables can be accessed from non-static methods using an object reference or by making the variable non-static.

• Static variables can be accessed from non-static methods by creating an object of the class containing the static variable.

• Alternatively, the static variable can be made non-static to be accessed directly from a non-static method.

• Attempting to access a static variable directly from a non-static method will result in a compilation error.

Coalnet Architecture of MMS Module is a system for managing and monitoring coal mines.

• Coalnet Architecture is designed to manage and monitor coal mines.

• It includes modules for tracking production, equipment maintenance, and safety.

• The MMS Module specifically focuses on maintenance management.

• It allows for scheduling and tracking of maintenance tasks, as well as inventory management.

• The architecture is scalable and can be customized to fit the needs of different mines.

• It is bu...read more

Deferred Tax Liabilities are future tax obligations that arise due to temporary differences between accounting and tax rules.

• Deferred Tax Liabilities are recorded on the balance sheet as a non-current liability.

• They represent taxes that a company will have to pay in the future when the temporary differences reverse.

• Temporary differences can arise from items such as depreciation, inventory valuation, and revenue recognition.

• Deferred Tax Liabilities are calculated by applying t...read more

Given a map of coffee shops and a person, find the closest n coffee shops to him.

• Use the person's location and calculate the distance to each coffee shop on the map.

• Sort the coffee shops by distance and return the closest n.

• Consider using a data structure like a priority queue to efficiently find the closest coffee shops.

Automate scenario to search for 'Mobile' on Amazon, retrieve name and price of results, store in custom class, and display on console.

• Use Selenium WebDriver to launch Amazon website

• Locate search box element and enter 'Mobile' text

• Retrieve name and price of search results using appropriate locators

• Store name and price in custom class with attributes 'name' and 'product'

• Display stored data on console

Implement stack using queue and return triplets with given target sum

• To implement stack using queue, we can use two queues and alternate between them for push and pop operations

• For returning triplets with given target sum, we can use a nested loop and a hash set to store visited elements

• We can then iterate through the array and check if the difference between target sum and current element exists in the hash set

Designing a thread-safe concurrent transaction application involves careful consideration of synchronization, locking mechanisms, and data consistency.

• Identify critical sections of code that need to be synchronized to prevent race conditions

• Use synchronization mechanisms such as locks, semaphores, or atomic operations to ensure mutual exclusion

• Consider using transactional memory or software transactional memory for managing concurrent transactions

• Implement data structures tha...read more

Airport Management System schema and ER diagram design

• Entities: Airport, Flight, Passenger, Employee, Schedule

• Attributes: Airport (code, name, location), Flight (number, destination, departure time), Passenger (name, age, contact info), Employee (ID, name, role), Schedule (flight number, date, time)

• Relationships: Airport has many Flights, Flight has many Passengers, Employee works at Airport, Flight has Schedule

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Identify the functional dependencies in the table

• Eliminate partial dependencies by breaking the table into multiple tables

• Eliminate transitive dependencies by further breaking down the tables

• Ensure each table has a primary key and all non-key attributes are fully functionally dependent on the primary key

PUT is used to update or replace an existing resource, while POST is used to create a new resource.

• PUT is idempotent, meaning multiple identical requests will have the same effect as a single request

• POST is not idempotent, meaning multiple identical requests may have different effects

• PUT is used to update an existing resource at a specific URI

• POST is used to create a new resource under a specific URI

• Example: PUT /users/123 updates user with ID 123, POST /users creates a new u...read more

HAVING clause is used with GROUP BY to filter groups, WHERE clause is used to filter rows.

• HAVING clause is used with GROUP BY clause to filter groups based on aggregate functions.

• WHERE clause is used to filter rows based on conditions.

• HAVING clause is used after GROUP BY clause, while WHERE clause is used before GROUP BY clause.

• HAVING clause can use aggregate functions, while WHERE clause cannot.

• Example: SELECT category, COUNT(*) FROM products GROUP BY category HAVING COUNT(*...read more

Multitasking is the ability of an operating system to run multiple tasks concurrently while multiprogramming is the ability to run multiple programs concurrently.

• Multitasking allows multiple tasks to run concurrently on a single processor system.

• Multiprogramming allows multiple programs to run concurrently on a single processor system.

• Multitasking is achieved through time-sharing, where the processor switches between tasks at a very high speed.

• Multiprogramming is achieved thr...read more

Convert a number to its English form for reading.

• Break the number into groups of three digits

• Convert each group to English words

• Combine the words with appropriate thousand/million/billion suffixes

UX focuses on the overall user experience, while UI focuses on the visual and interactive elements of a product.

• UX (User Experience) is about the overall experience a user has with a product, including usability, accessibility, and satisfaction.

• UI (User Interface) is specifically about the visual and interactive elements of a product, such as buttons, menus, and layout.

• UX design involves research, testing, and understanding user needs, while UI design focuses on creating visu...read more

Two objects created - one in the string pool and one in the heap.

• String 'a' is created in the string pool, while String 'b' is created in the heap.

• String pool is a special area in the heap memory where strings are stored to increase reusability and save memory.

• Using 'new' keyword always creates a new object in the heap, even if the content is the same as an existing string in the pool.

Only the original string 'Something' will be garbage collected.

• The concat method in Java does not modify the original string, but instead returns a new string with the concatenated value.

• In this case, 'a' remains as 'Something' and a new string 'Something New' is created, but not assigned to any variable.

• Since the new string is not stored in any variable, it will not be garbage collected.

Joins in SQL are used to combine rows from two or more tables based on a related column between them.

• Types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• INNER JOIN returns rows when there is at least one match in both tables.

• LEFT JOIN returns all rows from the left table and the matched rows from the right table.

• RIGHT JOIN returns all rows from the right table and the matched rows from the left table.

• FULL JOIN returns rows when there is a match in one of t...read more

Use the SQL query with ORDER BY and LIMIT to find the third highest salary.

• Use the SQL query: SELECT DISTINCT Salary FROM Employees ORDER BY Salary DESC LIMIT 2, 1

• The above query will return the third highest salary from the 'Employees' table

• Make sure to replace 'Employees' and 'Salary' with the appropriate table and column names

I prioritize issues based on impact, urgency, and complexity.

• Assess the impact of each issue on the system or users

• Consider the urgency of resolving each issue

• Evaluate the complexity of fixing each issue

• Prioritize critical issues that have high impact, urgency, and low complexity

• Create a priority list based on these factors

A zombie process is a process that has completed execution but still has an entry in the process table.

• Zombie processes occur when a child process finishes execution before the parent process can collect its exit status.

• The zombie process remains in the process table until the parent process calls wait() system call to read its exit status.

• Zombie processes do not consume any system resources but can clutter the process table if not properly handled.

Thrashing in an operating system occurs when the system is spending more time swapping data between memory and disk than actually executing tasks.

• Occurs when the system is overwhelmed with too many processes demanding memory

• Results in excessive swapping of data between RAM and disk

• Leads to a decrease in system performance as CPU spends more time on swapping than executing tasks

• Can be alleviated by optimizing memory usage or adding more physical memory

• Example: A system running...read more

Check if a string has balanced parentheses.

• Use a stack to keep track of opening parentheses.

• Iterate through the string and push opening parentheses onto the stack.

• When a closing parenthesis is encountered, pop from the stack and check if it matches the closing parenthesis.

• If stack is empty at the end and all parentheses are matched, the string has balanced parentheses.

The four pillars of OOPS are encapsulation, inheritance, polymorphism, and abstraction.

• Encapsulation: Bundling data and methods that operate on the data into a single unit. Example: Using private variables and public methods in a class.

• Inheritance: Allowing a new class to inherit properties and behavior from an existing class. Example: Creating a subclass that inherits from a superclass.

• Polymorphism: The ability to present the same interface for different data types. Example:...read more

Implement rate limiting, increase capacity, use caching, and implement security measures.

• Implement rate limiting to restrict the number of requests per client or IP address.

• Increase the capacity of the DNS infrastructure by adding more servers or upgrading existing ones.

• Use caching to store frequently accessed DNS records and reduce the load on the infrastructure.

• Implement security measures such as firewall rules to block malicious requests and protect against DDoS attacks.

Design considerations for a highly available application include redundancy, fault tolerance, load balancing, and disaster recovery.

• Implementing redundancy in critical components to ensure continuous operation

• Utilizing fault-tolerant architecture to handle failures without impacting availability

• Implementing load balancing to distribute traffic evenly across multiple servers

• Setting up disaster recovery mechanisms to quickly recover from unexpected outages

Factory Design Pattern is used to create objects without exposing the creation logic to the client.

• It provides a way to delegate the object creation to a factory class.

• It helps in achieving loose coupling between classes.

• It is useful when we have a super class with multiple sub-classes and based on input, we need to return one of the sub-class.

• Examples include: java.util.Calendar, java.text.NumberFormat, java.nio.charset.Charset

HTTP response codes indicate the status of a web request. There are 5 categories of codes.

• 1xx - Informational

• 2xx - Success

• 3xx - Redirection

• 4xx - Client Error

• 5xx - Server Error

I expect Oracle to provide robust and scalable solutions for the BFSI sector. I have worked on areas such as risk management, compliance, and customer analytics.

• Expect Oracle to offer comprehensive solutions tailored for the BFSI sector

• Worked on risk management, compliance, and customer analytics in BFSI

• Utilized Oracle tools for data analysis and reporting in banking and financial services

Find missing and repeating element in an array of 1 to n elements in O(n) time and O(1) space.

• Iterate through the array and for each element, mark the element at index equal to its value as negative. If the element is already negative, it is the repeating element.

• After marking all elements, the positive element's index + 1 is the missing element.

• Example: Array ['1', '2', '3', '3', '5'] - Repeating element is '3' and missing element is '4'.

The programming language used in the project is Python.

• Python is a high-level programming language known for its simplicity and readability.

• Some commonly used libraries in Python for network development include socket, requests, and scapy.

• The choice of libraries depends on the specific requirements of the project.

• For example, the socket library is used for low-level network programming, while requests is used for making HTTP requests.

• Scapy is a powerful library for packet man...read more