Week 4: PostgreSQL Advanced Features and Real-World Applications

Week 4: PostgreSQL Advanced Features and Real-World Applications (Days 22–30)

In Week 4, you’ll explore the most advanced PostgreSQL features to enhance your database skills. We will cover custom functions, triggers, and explore real-world applications for PostgreSQL. By the end of the week, you will have a strong understanding of PostgreSQL’s advanced functionalities, and you will be able to design efficient, scalable, and secure databases.

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Day 22: Introduction to Custom Functions

• What Are Custom Functions?
• Understand the concept of custom functions in PostgreSQL and how they allow you to encapsulate logic for reuse.
• Creating Functions in SQL:
• Learn how to create basic functions in PostgreSQL using SQL.

Example:

CREATE FUNCTION calculate_tax(price DECIMAL) RETURNS DECIMAL AS $$
BEGIN
    RETURN price * 0.10;
END;
$$ LANGUAGE plpgsql;

• Using PL/pgSQL for More Complex Logic:
• Explore PostgreSQL’s PL/pgSQL language to write more advanced functions with loops, conditions, and error handling.

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Day 23: Advanced Custom Functions and Triggers

• Advanced Function Features:
• Learn about return types, parameters, and the ability to handle exceptions in custom functions.
• Introduction to Triggers:
• Understand how triggers are used to automatically execute a function in response to events such as insert, update, or delete.

Example:

CREATE TRIGGER after_insert_user
AFTER INSERT ON users
FOR EACH ROW
EXECUTE FUNCTION log_new_user();

• Creating Triggers:
• Learn to create triggers for auditing, logging, or modifying data automatically.

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Day 24: Using Triggers for Data Integrity and Automation

• Enforcing Data Integrity:
• Learn how to use triggers to enforce constraints and rules on data automatically.
• Using BEFORE and AFTER Triggers:
• Understand the differences between BEFORE and AFTER triggers and when to use each.

Example:

-- BEFORE trigger to check data validity before insertion
CREATE TRIGGER validate_email_before_insert
BEFORE INSERT ON users
FOR EACH ROW
EXECUTE FUNCTION validate_email_format();

• Trigger Optimization:
• Explore how to optimize triggers to avoid performance overhead.

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Day 25: Views, Materialized Views, and Functions

• Understanding Views:
• Learn how to create views to simplify complex queries and abstract them for easier use.

Example:

CREATE VIEW user_sales AS
SELECT user_id, SUM(amount) AS total_sales
FROM sales
GROUP BY user_id;

• Materialized Views for Performance:
• Understand how materialized views help improve performance by storing the result of complex queries.
• Using Functions with Views:
• Learn how to combine custom functions and views to create reusable logic in your PostgreSQL database.

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Day 26: Working with Complex Queries and Subqueries

• Optimizing Complex Queries:
• Learn how to optimize complex queries by using subqueries and joins effectively.
• Using CTEs (Common Table Expressions):
• Understand the purpose of CTEs and how they can simplify complex queries.

Example:

WITH recent_sales AS (
    SELECT user_id, SUM(amount) AS total_sales
    FROM sales
    WHERE sale_date > CURRENT_DATE - INTERVAL '1 month'
    GROUP BY user_id
)
SELECT * FROM recent_sales;

• Window Functions:
• Learn about window functions like ROW_NUMBER(), RANK(), and PARTITION BY to perform complex analytics.

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Day 27: Database Optimization and Indexing Best Practices

• Optimizing Query Performance:
• Learn advanced techniques to improve the performance of your PostgreSQL database, including query rewriting, indexing, and partitioning.
• Advanced Indexing Techniques:
• Understand advanced indexing options like partial indexes, expression-based indexes, and GiST indexes.

Example:

CREATE INDEX idx_user_email ON users (email);

• Query Tuning with EXPLAIN:
• Learn to interpret the results of the EXPLAIN command to understand how PostgreSQL executes your queries.

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Day 28: PostgreSQL Data Types and Custom Data Types

• Working with JSON and JSONB:
• Learn how to work with JSON and JSONB data types in PostgreSQL, and how to store, query, and manipulate JSON data.

Example:

CREATE TABLE products (
    id SERIAL PRIMARY KEY,
    attributes JSONB
);

INSERT INTO products (attributes) VALUES ('{"color": "red", "size": "L"}');

• Creating Custom Data Types:
• Learn how to define custom data types to fit specific needs in your database.

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Day 29: PostgreSQL Security Best Practices

• Data Encryption:
• Understand the importance of data encryption and how to implement it in PostgreSQL.
• Role-Based Access Control:
• Learn about PostgreSQL’s role-based access control (RBAC) system to manage user privileges.

Example:

CREATE ROLE read_only;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO read_only;

• Auditing and Logging:
• Learn how to configure PostgreSQL’s auditing and logging capabilities to track changes and monitor activity.

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Day 30: Final Project and Real-World Application

• Building a Real-World Application:
• Use everything you’ve learned to build a real-world PostgreSQL application, such as a simple web app or data analysis project.
• Applying Advanced Features:
• Incorporate custom functions, triggers, indexing, and security features into your project.
• Sharing and Reflecting on Your Progress:
• Review your PostgreSQL journey, reflect on your progress, and share your project on GitHub or with a community for feedback.

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Conclusion

Week 4 wraps up your PostgreSQL learning journey with a deep dive into advanced features, custom functions, triggers, security, and real-world applications. By the end of the week, you’ll have the expertise to build and optimize complex databases, create secure applications, and apply PostgreSQL in production environments.

Now that you’ve completed the 30-day PostgreSQL learning plan, continue practicing and exploring more advanced topics to further sharpen your skills!