This repository is a helpful guide for anyone working with data. It covers everything you need to know about databases, including SQL and NoSQL databases, making them faster, and keeping them secure. It also has real-world examples to help you understand how to use databases in practice.
I created this repository to help myself and others overcome database challenges and build reliable, high-performance data systems. Throughout my career, I've faced numerous database issues, including slow SQL queries and poorly optimized tables. I realized that having a deep understanding of databases is essential for creating effective data systems.
To improve my skills and tackle these challenges, I decided to create a comprehensive guide to databases. I've included essential concepts, tools, and real-world case studies to provide a well-rounded understanding of database engineering.
Setting up a database can be a challenging task, especially if you're new to databases. However, to make it easier, here are a few helpful resources:
Sql interpreters online:
Sample Databases:
These online SQL interpreters allow you to test SQL queries without the need for any local installation, making it easy to get started. The sample databases provide a useful starting point for testing and exploring different database systems.
| Topic | Description | Notes |
|---|---|---|
| Databases Intro | An overview of what databases are and their fundamental concepts. |  |
| Types of Databases | Exploring various kinds of databases, such as relational, NoSQL, and more. | |
| Database Management Systems (DBMS) | Delves into systems that manage databases, their functions, and types. | |
| Data Models | Discusses different methods of structuring and representing data within a database. | |
| Glossary | A compilation of key terms and definitions related to databases. | |
| Topic | Description | Notes |
|---|---|---|
| Requirements Analysis | Process of determining user needs and conditions for the development of a new database system. | |
| Normalization | A technique to minimize redundancy and dependency by organizing fields and table of a database. | |
| Denormalization | A technique to optimize database performance by selectively introducing redundancy and organizing tables. | |
| Indexing Strategies | Approaches to optimize the performance of database queries using indexes. | |
| Data Integrity and Constraints | Ensuring the accuracy and consistency of data in a database and the rules governing permissible database operations. | |
| Topic | Description | Notes |
|---|---|---|
| Intro to SQL | An overview of SQL, its history, and its significance in database management. | |
| Data Definition Language (DDL) | Commands used to define and manage database structures, such as CREATE, ALTER, and DROP. | |
| Data Manipulation Language (DML) | Commands for accessing and manipulating data, such as SELECT, INSERT, UPDATE, and DELETE. | |
| Data Control Language (DCL) | Commands related to data security, such as GRANT and REVOKE permissions. | |
| Transaction Control Language (TCL) | Commands that manage transactions in a database, such as COMMIT, ROLLBACK, and SAVEPOINT. | |
| Joins, Subqueries, and Views | Techniques to combine data from different tables and create virtual tables or complex queries in SQL. | |
| Stored Procedures and Functions | Reusable SQL code saved in the database to perform specific tasks or calculations. | |
| Triggers | Automated actions that are executed in response to specific changes in the database. | |
| Hierarchical Data | Techniques and strategies to represent tree-like data structures in relational databases. | |
| Topic | Description | Notes |
|---|---|---|
| What is a Transaction | An overview of what database transactions are and their significance in ensuring reliable data operations. | |
| Atomicity | Discusses the all-or-nothing nature of transactions, ensuring that operations are either fully completed or fully reverted. | |
| Consistency | Delves into ensuring that transactions maintain database integrity and do not violate predefined rules or constraints. | |
| Isolation | Discusses how transactions operate independently and how their effects can be isolated from other concurrent transactions. | |
| Durability | Explores how the results of a transaction are permanent and cannot be lost once committed. | |
| Topic | Description | Notes |
|---|---|---|
| How Tables and Indexes are Stored on Disk | Explores the underlying mechanisms databases use to store tables and indexes on disk, including physical layouts and data structures. | |
| Row-based vs. Column-based Databases | Compares the two storage formats, discussing the advantages and drawbacks of each, especially in terms of performance and use cases. | |
| Primary Key vs. Secondary Key | Differentiates between the primary and secondary keys, focusing on their roles, characteristics, and how they impact database performance and design. | |
| Database Pages | Delves into the concept of database pages, explaining how they are used to store data and facilitate efficient read/write operations. | |
| Indexing | Provides an overview of indexing strategies, types of indexes, and how they enhance query performance by reducing data search times. | |
| Topic | Description | Notes |
|---|---|---|
| Partitioning Types | Different methods of dividing a database or its elements into parts and distributing them across a system. | |
| Working with Billion-Row Table | Techniques and best practices for efficiently handling and querying massive tables. | |
| Consistent Hashing | A technique used in distributing data across multiple servers, ensuring minimal rehashing when servers are added or removed. | |
| Sharding | The process of breaking up large tables into smaller chunks and distributing them across multiple servers. | |
| Partitioning vs. Sharding | Discussing the differences, similarities, and appropriate use-cases for partitioning and sharding. | |
| CAP Theorem | A principle outlining the trade-offs between consistency, availability, and partition tolerance in distributed databases. | |
| Eventual Consistency | A consistency model which allows temporary inconsistencies but ensures that eventually all replicas converge to the same value. | |
| Distributed Database Systems | Overview of the systems and architectures that support databases spread across multiple machines or locations. | |
| Topic | Description | Notes |
|---|---|---|
| Shared vs. Exclusive Locks | Differences between shared and exclusive locking mechanisms. | |
| Deadlocks | Understanding and resolving situations where locks block each other. | |
| Two-Phase Locking | The protocol for acquiring and releasing locks to ensure consistency. | |
| Double Booking Problem | Issues arising from concurrent transactions booking the same resource. | |
| Phantom Reads | An exploration of a specific concurrency issue where a transaction reads different rows after a subsequent read due to inserts or deletes by a concurrent transaction. | |
| Serializable vs. Repeatable Read | Discusses the difference between two isolation levels in databases and their impact on concurrency and consistency. | |
| Topic | Description | Notes |
|---|---|---|
| Query Optimization Techniques | Methods to enhance the efficiency of database queries. | |
| Indexing Strategies | Techniques for using indexes to speed up query performances. | |
| Database Caching | Storing data in cache to improve retrieval times. | |
| Materialized Views | Precomputed views for faster data access. | |
| Accessing Database in Code | Best practices for database interactions within applications. | |
| Topic | Description | Notes |
|---|---|---|
| Introduction to Replication | Overview of database replication concepts. | |
| Master-Standby Replication | Exploring the master-standby replication method. | |
| Multi-Master Replication | Delving into multi-master replication techniques. | |
| Synchronous vs. Asynchronous Replication | Comparing synchronous and asynchronous replication. | |
| Topic | Description | Notes |
|---|---|---|
| NoSQL Databases Intro | Introduction to non-relational database concepts. | |
| Types of NoSQL Databases | Overview of various NoSQL database types. | |
| Querying NoSQL Databases | Techniques for querying non-relational databases. | |
| CRUD in SQL vs. NoSQL | Differences in CRUD operations between SQL and NoSQL. | |
| Topic | Description | Notes |
|---|---|---|
| Backup and Recovery Strategies | Strategies to backup and restore database data. | |
| Database Security | Measures to protect data and maintain its integrity. | |
| Capacity Planning | Predicting and addressing database growth needs. | |
| Database Migration | Process of moving a database from one environment to another. | |
| Performance Monitoring and Tuning | Observing and optimizing database performance. | |
| Real-life Challenges | Practical issues faced when managing databases. | |
| SQL Injection | A type of security vulnerability in database applications. | |
| Topic | Description | Notes |
|---|---|---|
| SQLite | A lightweight, serverless, self-contained SQL database engine commonly used in mobile apps and small-scale applications. | |
| MySQL | A widely-used, open-source relational database management system known for its fast performance and reliability. | |
| PostgreSQL | An advanced, enterprise-class open-source relational database system supporting both SQL and procedural languages. | |
| MongoDB | A popular NoSQL database, designed for scalability and flexibility, favoring JSON-like documents for data representation. | |
| Neo4j | A leading graph database that utilizes nodes and relationships to represent and store data for complex relationships. | |
| AWS Services | Overview of Amazon Web Services' database offerings, covering both relational and non-relational database services. | |
| Choosing Database | Guidelines and factors to consider when selecting a database engine for specific application needs and scenarios. | |
- https://www.coursehero.com/sitemap/schools/11-Cornell-University/courses/44816-CS4320/
- https://15445.courses.cs.cmu.edu/fall2023/
- https://pgexercises.com/
- http://www.sql-tutorial.ru/
- https://softwareengineering.stackexchange.com/questions/194340/why-are-nosql-databases-more-scalable-than-sql/194408#194408
- https://sqlzoo.net/wiki/SQL_Tutorial
- http://coding-geek.com/how-databases-work/
- https://algodaily.com/lessons/databases-and-sql-cheat-sheet-for-interviews
- https://datalemur.com/sql-interview-questions
- Check this link out if you have a trouble understanding JOINS: https://joins.spathon.com/