Oracle

Role: Not Specified (Implied SDE/Developer)

College: Not Specified (On-Campus)

Interview Date: 2024

Interview Type: On-Campus, Full-Time

Result: Selected

Difficulty: Medium

Rounds: 3 rounds

Topics Asked: Data Structures and Algorithms (Binary Search, Aggressive Cows, Sort a LinkedList (Merge Sort), Time complexity analysis of Binary Search), Operating Systems (Deadlock, Dining Philosopher Problem, Process synchronization, Semaphores, wait(), signal(), bootstrap), DBMS and SQL (Table, View, RDBMS, SQL Commands: DDL, DML, DCL, TCL, Difference between DROP, TRUNCATE, DELETE, CAP Theorem, 3NF vs BCNF, SQL queries with joins and subqueries), Java (Heap and stack memory, Memory-related errors, Garbage Collection, Static and dynamic binding, JVM, Platform independence, Singleton class, JAR files), Project Analysis (Design schema, ER diagram, Normalization, Machine Learning project)

Experience:

This Oracle interview experience is from an on-campus drive in 2024.

Round 1: HackerRank Test (100 Minutes). This online assessment consisted of one medium-level Data Structures and Algorithms (DSA) question (a modified "Aggressive Cows" problem, involving binary search on answers), 20 technical questions covering Operating Systems, DBMS, Computer Networks, and other CS fundamentals, and 15 general aptitude and communication questions.

Round 1 (Technical - 50 Mins). After introductions, the interviewer confirmed Java as the primary language. Java questions included: "Explain heap and stack memory", "Memory-related errors in Java (StackOverflowError and OutOfMemoryError)", "Explain Garbage Collection", "What is static and dynamic binding?", "JVM and platform independence of Java", "Singleton class example", and "What are JAR files?". DBMS and SQL questions covered: "What is a table and a view?", "Explain RDBMS and SQL Commands: DDL, DML, DCL, and TCL", "Difference between DROP, TRUNCATE, and DELETE commands", "CAP Theorem and its trade-offs", "Difference between 3NF and BCNF", and writing SQL queries based on joins and basic subqueries. For DSA, the candidate was asked to "Sort a LinkedList" using the merge sort approach, explain its intuition, and analyze its time complexity. The reason for binary search's time complexity being log(N) and not N/2 was also asked. Operating Systems questions included: "What is a deadlock and how to avoid it?", "Explain the Dining Philosopher Problem", "Process synchronization", "What are Semaphores?", "Explain wait() and signal()", and "What is bootstrap?". The interviewer was supportive and helped with answers to OS questions.

Round 2 (Technical - 45 mins). This round involved an in-depth analysis of the candidate's projects. Questions included: "Design schema and draw ER diagram for a DBMS project (Airport Management System)" and "Normalize a given table" (up to 3NF). There was also a prolonged discussion on the candidate's Machine Learning project, testing in-depth knowledge.

Tips and Suggestions. The candidate emphasized being confident and approachable, only including skills on the resume that one is confident in, not panicking if stuck, asking for clarification, explaining the thought process clearly, and preparing thoughtful questions for the interviewer.