Databases
1 Introduction to Databases
1-1 Definition of Databases
1-2 Importance of Databases in Modern Applications
1-3 Types of Databases
1-3 1 Relational Databases
1-3 2 NoSQL Databases
1-3 3 Object-Oriented Databases
1-3 4 Graph Databases
1-4 Database Management Systems (DBMS)
1-4 1 Functions of a DBMS
1-4 2 Popular DBMS Software
1-5 Database Architecture
1-5 1 Centralized vs Distributed Databases
1-5 2 Client-Server Architecture
1-5 3 Cloud-Based Databases
2 Relational Database Concepts
2-1 Introduction to Relational Databases
2-2 Tables, Rows, and Columns
2-3 Keys in Relational Databases
2-3 1 Primary Key
2-3 2 Foreign Key
2-3 3 Composite Key
2-4 Relationships between Tables
2-4 1 One-to-One
2-4 2 One-to-Many
2-4 3 Many-to-Many
2-5 Normalization
2-5 1 First Normal Form (1NF)
2-5 2 Second Normal Form (2NF)
2-5 3 Third Normal Form (3NF)
2-5 4 Boyce-Codd Normal Form (BCNF)
3 SQL (Structured Query Language)
3-1 Introduction to SQL
3-2 SQL Data Types
3-3 SQL Commands
3-3 1 Data Definition Language (DDL)
3-3 1-1 CREATE
3-3 1-2 ALTER
3-3 1-3 DROP
3-3 2 Data Manipulation Language (DML)
3-3 2-1 SELECT
3-3 2-2 INSERT
3-3 2-3 UPDATE
3-3 2-4 DELETE
3-3 3 Data Control Language (DCL)
3-3 3-1 GRANT
3-3 3-2 REVOKE
3-3 4 Transaction Control Language (TCL)
3-3 4-1 COMMIT
3-3 4-2 ROLLBACK
3-3 4-3 SAVEPOINT
3-4 SQL Joins
3-4 1 INNER JOIN
3-4 2 LEFT JOIN
3-4 3 RIGHT JOIN
3-4 4 FULL JOIN
3-4 5 CROSS JOIN
3-5 Subqueries and Nested Queries
3-6 SQL Functions
3-6 1 Aggregate Functions
3-6 2 Scalar Functions
4 Database Design
4-1 Entity-Relationship (ER) Modeling
4-2 ER Diagrams
4-3 Converting ER Diagrams to Relational Schemas
4-4 Database Design Best Practices
4-5 Case Studies in Database Design
5 NoSQL Databases
5-1 Introduction to NoSQL Databases
5-2 Types of NoSQL Databases
5-2 1 Document Stores
5-2 2 Key-Value Stores
5-2 3 Column Family Stores
5-2 4 Graph Databases
5-3 NoSQL Data Models
5-4 Advantages and Disadvantages of NoSQL Databases
5-5 Popular NoSQL Databases
6 Database Administration
6-1 Roles and Responsibilities of a Database Administrator (DBA)
6-2 Database Security
6-2 1 Authentication and Authorization
6-2 2 Data Encryption
6-2 3 Backup and Recovery
6-3 Performance Tuning
6-3 1 Indexing
6-3 2 Query Optimization
6-3 3 Database Partitioning
6-4 Database Maintenance
6-4 1 Regular Backups
6-4 2 Monitoring and Alerts
6-4 3 Patching and Upgrading
7 Advanced Database Concepts
7-1 Transactions and Concurrency Control
7-1 1 ACID Properties
7-1 2 Locking Mechanisms
7-1 3 Isolation Levels
7-2 Distributed Databases
7-2 1 CAP Theorem
7-2 2 Sharding
7-2 3 Replication
7-3 Data Warehousing
7-3 1 ETL Processes
7-3 2 OLAP vs OLTP
7-3 3 Data Marts and Data Lakes
7-4 Big Data and Databases
7-4 1 Hadoop and HDFS
7-4 2 MapReduce
7-4 3 Spark
8 Emerging Trends in Databases
8-1 NewSQL Databases
8-2 Time-Series Databases
8-3 Multi-Model Databases
8-4 Blockchain and Databases
8-5 AI and Machine Learning in Databases
9 Practical Applications and Case Studies
9-1 Real-World Database Applications
9-2 Case Studies in Different Industries
9-3 Hands-On Projects
9-4 Troubleshooting Common Database Issues
10 Certification Exam Preparation
10-1 Exam Format and Structure
10-2 Sample Questions and Practice Tests
10-3 Study Tips and Resources
10-4 Final Review and Mock Exams
1-5 1 Centralized vs Distributed Databases Explained

1-5 1 Centralized vs Distributed Databases Explained

Key Concepts

Centralized Databases

Centralized Databases store all data in a single, central location. This central server manages all data operations, including storage, retrieval, and updates. Centralized databases are simpler to manage and maintain but can become bottlenecks as data volume increases.

Example: A company's HR system where all employee records are stored on a single server. This server handles all queries and updates related to employee data.

Distributed Databases

Distributed Databases store data across multiple, interconnected nodes or servers. Each node can handle data operations independently, providing better scalability and fault tolerance. Distributed databases are more complex to manage but offer higher performance and availability.

Example: A global e-commerce platform where customer data is distributed across multiple servers located in different regions. Each server handles data operations for its local users, ensuring faster response times and reduced latency.

Data Replication

Data Replication involves copying data from one database server to another, ensuring that multiple copies of the data exist across different locations. This enhances data availability and reliability, as well as providing backup in case of server failures.

Example: A social media platform replicates user data across multiple data centers to ensure that users can access their data even if one data center goes offline.

Data Partitioning

Data Partitioning involves splitting a large database into smaller, more manageable pieces called partitions. Each partition can be stored on a different server, improving performance and scalability. Partitioning can be done based on various criteria, such as geographical location, time, or user type.

Example: A financial institution partitions its transaction database by date, storing recent transactions on faster, more accessible servers and older transactions on slower, less frequently accessed servers.

Conclusion

Understanding the differences between Centralized and Distributed Databases, along with concepts like Data Replication and Partitioning, is crucial for designing robust and scalable database systems. Centralized databases offer simplicity but may struggle with large volumes of data, while Distributed databases provide better scalability and fault tolerance but require more complex management.