Core Operating System Concepts Explained
Operating System Fundamentals
System Calls and System Programs
System calls provide an interface between a process and the operating system. They allow user-level processes to request services from the operating system which the process itself is not allowed to perform. In handling the trap, the operating system enters kernel mode, where it has access to privileged instructions and can perform the desired service on behalf of the user-level process. Due to the critical nature of these operations,
Read MoreUnderstanding Network Protocols and Algorithms
Classful Addressing System
Classful addressing is a method used in the early days of the Internet to allocate IP addresses based on fixed-length prefixes. This system divides the entire IPv4 address space into five classes (A, B, C, D, and E), each with a specific range of addresses and a defined prefix length. Here’s a breakdown of the classes:
Class A
Prefix Length: 8 bits, with the first bit set to 0.
Network Range: 0.0.0.0 to 127.255.255.255.
Number of Networks: 128.
Usable Hosts per Network:
Mastering Network Routing Protocols and Concepts
Understanding Core Network Routing Concepts
Key Routing Terminology
- Router: A computing device comprising hardware and software, including a CPU, RAM, ROM, and an operating system. Its primary function is to connect multiple networks and forward data packets between them.
- Routing Table: A data file stored in RAM that contains route information for both directly connected and remote networks.
- Remote Network: A network that can only be reached by forwarding data packets through another router.
- Static Routes:
Essential Concepts in Big Data Analytics and Machine Learning
Data Analytics Life Cycle in Big Data
Discovery
Goal: Understand the problem and define objectives. Identify business challenges, determine project scope and potential value, and assess available resources (data, tools, skills). Understand data sources and feasibility.
Example: A retail company wants to improve sales forecasting using big data analytics.
Data Preparation
Goal: Collect, clean, and organize the data. Gather data from various sources (structured, semi-structured, unstructured). Clean and
Python Hash Tables: Chaining vs. Linear Probing
Introduction to Hash Tables
Hash tables are fundamental data structures that store key-value pairs. They provide efficient data retrieval, insertion, and deletion operations. The core idea behind a hash table is to use a hash function to map keys to indices (or “buckets”) in an array. However, different keys can sometimes map to the same index, leading to a collision. Resolving these collisions is crucial for the hash table’s performance.
Collision Resolution Strategies
This document demonstrates two
Read MoreJava Backend Development Essentials
Core JDBC Concepts and Usage
JDBC Query Methods: executeQuery() vs. executeUpdate()
The method executeQuery() is used when you want to retrieve data from the database, typically using a SELECT statement. It returns a ResultSet object which contains the data returned by the query.
Example:
ResultSet rs = statement.executeQuery("SELECT * FROM users");
while (rs.next()) {
System.out.println(rs.getString("username"));
}The method executeUpdate() is used for SQL statements that change the data in the