Study Material

  ✅ What is a Database? A Database is an organized collection of data that can be easily accessed, managed, and updated. 🧠 Example : Your college stores data of students — names, roll numbers, marks — in a structured format. ✅ What is a DBMS? A Database Management System (DBMS) is software that interacts with users, applications, and the database itself to capture and analyze data. 💡 DBMS Examples: MySQL Oracle PostgreSQL MongoDB (NoSQL DB) ✅ Advantages of DBMS over File System File System DBMS Data Redundancy Reduced Redundancy No data sharing Multi-user support No data security High security Difficult backup Easy backup & recovery Complex queries Easy SQL-based queries ✅ Types of DBMS Type Description Example Hierarchical Parent-child IBM IMS Network Graph structure IDS Relational Tables (rows/columns) MySQL, Oracle Object-oriented Stores data as objects Versant 🧠 MCA Exams usually focus on Relational DBMS (RDBMS). ✅ Components of DBMS Ha...

We’ll break it down into: 📘 1. Important Theory Topics (Frequently Asked in Exams) 💡 2. Expected Questions from Each Topic 💻 3. Basic SQL Practice (For Viva / Practical Exams) 📘 1. Important Theory Topics Unit Topic Must-Know Concepts 1 Introduction to DBMS Definition, advantages, DBMS vs RDBMS, applications 2 Data Models & ER Model Entity, attributes, relationships, ER diagrams 3 Relational Model Tuple, attribute, schema, keys (primary, foreign) 4 Relational Algebra Select, Project, Join, Union, Set Difference 5 SQL Basics CREATE, INSERT, SELECT, UPDATE, DELETE, WHERE, JOINS 6 Normalization 1NF, 2NF, 3NF, BCNF, functional dependency 7 Transaction Management ACID properties, commit, rollback 8 Indexing & Storage B+ trees, hashing, file organization 💡 2. Important Questions to Study ✅ Short Questions : What is DBMS? List its advantages. Define primary and foreign keys with examples. What is normalization? ✅ Long Questions (most scoring): Draw and exp...

🎯 Goals for Today Understand how sorting works and why it’s needed Learn and implement: Bubble Sort Selection Sort Insertion Sort Analyze time & space complexities Practice beginner sorting problems 📘 1. Why Sorting Matters Sorting helps: Optimize searching (e.g., binary search) Solve problems like duplicates, frequency, etc. Prepare data for algorithms like two pointers , greedy , divide & conquer , etc. 🔁 2. Sorting Algorithms 🔹 Bubble Sort Repeatedly swap adjacent elements if they are in the wrong order. public class BubbleSort { public static void bubbleSort ( int [] arr) { int n = arr.length; for ( int i = 0 ; i < n - 1 ; i++) { boolean swapped = false ; for ( int j = 0 ; j < n - i - 1 ; j++) { if (arr[j] > arr[j + 1 ]) { // swap int temp = arr[j]; arr[j] = arr[j + 1 ]; ...

  🎯 Goal: Learn Bubble Sort and sort arrays. Understand how Binary Search works. Compare Linear vs Binary Search. Practice problems on sorted arrays. 🧠 Theory ✅ Bubble Sort: Repeatedly compares adjacent elements and swaps them if they’re in the wrong order. Worst-case time complexity: O(n²) Best-case (already sorted): O(n) with optimization 👨‍💻 Bubble Sort in C # include <stdio.h> int main () { int arr[ 100 ], n, i, j, temp; printf ( "Enter number of elements: " ); scanf ( "%d" , &n); printf ( "Enter %d elements:\n" , n); for (i = 0 ; i < n; i++) scanf ( "%d" , &arr[i]); // Bubble Sort for (i = 0 ; i < n - 1 ; i++) { int swapped = 0 ; for (j = 0 ; j < n - i - 1 ; j++) { if (arr[j] > arr[j + 1 ]) { // Swap temp = arr[j]; arr[j] = arr[j + 1 ]; ...

🔹 Linear Search in Java public class LinearSearch { public static int linearSearch ( int [] arr, int key) { for ( int i = 0 ; i < arr.length; i++) { if (arr[i] == key) return i; } return - 1 ; // Not found } public static void main (String[] args) { int [] arr = { 5 , 3 , 8 , 2 , 9 }; int key = 8 ; int index = linearSearch(arr, key); System.out.println( "Element found at index: " + index); } } 🔹 Binary Search in Java (Iterative) public class BinarySearch { public static int binarySearch ( int [] arr, int key) { int start = 0 , end = arr.length - 1 ; while (start <= end) { int mid = start + (end - start) / 2 ; if (arr[mid] == key) return mid; else if (arr[mid] < key) start = mid + 1 ; else end = mid - 1 ; } return - 1 ; } public static voi...

🎯 Goals: Understand Linear Search and Binary Search Learn when and how to use each Solve real interview problems using searching techniques 🔍 1. Linear Search 📘 Definition: Linearly checks each element one by one. Used when the array is unsorted . ✅ Code Example: public static int linearSearch ( int [] arr, int key) { for ( int i = 0 ; i < arr.length; i++) { if (arr[i] == key) return i; } return - 1 ; // Not found } 🧠 2. Binary Search 📘 Definition: Used on sorted arrays . It divides the search space in half each time — O(log N) time complexity. ✅ Code (Iterative Approach): public static int binarySearch ( int [] arr, int key) { int start = 0 , end = arr.length - 1 ; while (start <= end) { int mid = start + (end - start) / 2 ; if (arr[mid] == key) return mid; else if (arr[mid] < key) start = mid + 1 ; else end = mid - 1 ; } return - 1 ; } ✅ Code (Recu...

  ✅ 1. Find Maximum and Minimum in an Array # include <stdio.h> int main () { int n, i; int arr[ 100 ], max, min; printf ( "Enter number of elements: " ); scanf ( "%d" , &n); printf ( "Enter %d elements:\n" , n); for (i = 0 ; i < n; i++) { scanf ( "%d" , &arr[i]); } max = min = arr[ 0 ]; for (i = 1 ; i < n; i++) { if (arr[i] > max) max = arr[i]; if (arr[i] < min) min = arr[i]; } printf ( "Maximum: %d\n" , max); printf ( "Minimum: %d\n" , min); return 0 ; } ✅ 2. Count Occurrences of a Given Number # include <stdio.h> int main () { int n, x, count = 0 ; int arr[ 100 ]; printf ( "Enter number of elements: " ); scanf ( "%d" , &n); printf ( "Enter %d elements:\n" , n); for ( int i = 0 ; i < n; i++) { ...

  🎯 Goal: Understand arrays in C. Learn how to use loops with arrays . Implement Linear Search algorithm. Practice multiple array-based programs. 🧠 Theory: What is an Array? An array is a collection of elements stored in contiguous memory . All elements must be of the same type . Indexing starts from 0 in C. 🔧 Declaration and Initialization int arr[ 5 ]; // Declaration int arr[ 5 ] = { 1 , 2 , 3 , 4 , 5 }; // Initialization 👨‍💻 Basic Program: Input & Output in Arrays # include <stdio.h> int main () { int arr[ 5 ]; printf ( "Enter 5 numbers:\n" ); for ( int i = 0 ; i < 5 ; i++) { scanf ( "%d" , &arr[i]); } printf ( "You entered:\n" ); for ( int i = 0 ; i < 5 ; i++) { printf ( "%d " , arr[i]); } return 0 ; } 🔍 Linear Search in C ➕ Problem: Given an array and a number x , find if x exists in the array. ✅ Code...