10+ Oracle Interview Questions and Answers

Different sorting methods are beneficial in different scenarios based on factors like time complexity, space complexity, and input size.

• Quick Sort: Best for large datasets due to its average time complexity of O(n log n)

• Bubble Sort: Simple and easy to implement, but inefficient for large datasets with its time complexity of O(n^2)

• Merge Sort: Stable and efficient for large datasets with its time complexity of O(n log n)

• Insertion Sort: Efficient for small datasets or nearly sor...read more

Web Sockets is a communication protocol that provides full-duplex communication channels over a single TCP connection.

• Web Sockets allow for real-time, bi-directional communication between a client and a server.

• They are commonly used in chat applications, online gaming, and live data streaming.

• Web Sockets use the ws:// or wss:// protocol scheme in URLs.

• The protocol is initiated with a handshake between the client and server.

• Once the connection is established, data can be sent ...read more

Asymmetric encryption algorithms use a pair of keys to encrypt and decrypt data, providing secure communication.

• RSA (Rivest-Shamir-Adleman) is a popular asymmetric encryption algorithm.

• Elliptic Curve Cryptography (ECC) is another commonly used asymmetric encryption algorithm.

• Asymmetric encryption is slower than symmetric encryption but provides better security.

• Public key is used for encryption and private key is used for decryption in asymmetric encryption.

Indexing typically uses data structures like B-trees or hash tables for efficient retrieval, with time complexity of O(log n) or O(1) respectively.

• Common data structures for indexing include B-trees and hash tables

• B-trees are typically used for indexing in databases due to their balanced nature and efficient search operations

• Hash tables are used for indexing in scenarios where constant time lookup is desired, but may have collisions requiring additional handling

Different data structures like arrays, linked lists, trees, graphs, and their indexing problems and solutions.

• Arrays: indexing is O(1), but insertion/deletion at arbitrary position is O(n)

• Linked Lists: indexing is O(n), but insertion/deletion at arbitrary position is O(1)

• Trees: indexing depends on the type of tree (e.g. binary search tree, AVL tree)

• Graphs: indexing can be done using adjacency lists or matrices

• Hash Tables: indexing is O(1) on average, but can have collisions

ACID properties are a set of properties that guarantee reliability and consistency in database transactions.

• Atomicity: Ensures that either all operations in a transaction are completed successfully or none at all.

• Consistency: Ensures that the database remains in a consistent state before and after the transaction.

• Isolation: Ensures that the execution of multiple transactions concurrently does not interfere with each other.

• Durability: Ensures that once a transaction is committ...read more

Time complexity of recursive fibonacci code is O(2^n)

• The time complexity of a recursive fibonacci code is exponential, O(2^n)

• This is because each call branches into two recursive calls, leading to exponential growth

• For example, calculating fibonacci(5) would result in 15 function calls

Indexing in DBMS is a technique used to improve the performance of queries by allowing faster retrieval of data.

• Indexes are data structures that store a small portion of the table data in an optimized format for quick retrieval.

• They help in speeding up data retrieval operations like SELECT, UPDATE, DELETE queries.

• Examples of indexes include primary keys, unique keys, and composite keys.

Processes are independent instances of a program, while threads are smaller units within a process sharing resources.

• Processes have their own memory space, while threads share the same memory space within a process.

• Processes are heavyweight, requiring more resources, while threads are lightweight.

• Processes communicate with each other through inter-process communication mechanisms, while threads can communicate directly.

• Example: A web browser running multiple tabs is a process...read more