PostgreSQL Mastery: From SQL to Scalable Systems

Course Duration: Self-paced (Estimated 3-4 Months) Prerequisites: Basic understanding of SQL is helpful, but the course covers foundations.

Module 1: The Postgres Foundation (Beginner)

1. Introduction & Setup

• Why Postgres? Object-Relational features, reliability, and open-source nature.
• Installation: Setting up PostgreSQL on Local OS vs. using Docker (The modern standard).
• Tools:
  • pgAdmin 4: The standard GUI.
  • psql: Mastering the Command Line Interface (Crucial for pros).
  • DBeaver: A universal alternative.

2. Core SQL in Postgres

• Basic CRUD: SELECT, INSERT, UPDATE, DELETE.
• The psql Slash Commands: \l (list databases), \c (connect), \d (describe table), \dt (show tables).
• Postgres Data Types:
  • Standard: Integer, Numeric, Varchar, Boolean.
  • Unique: UUID, Arrays (Lists inside a cell), Ranges.

3. Constraints & Integrity

• Primary Keys: Integers (SERIAL / IDENTITY) vs. UUIDs (gen_random_uuid()).
• Foreign Keys: Enforcing relationships (Cascade Delete/Update).
• Check Constraints: Validating data at the row level (e.g., CHECK (price > 0)).
• Unique & Not Null.

---

Module 2: Advanced Data Manipulation (Intermediate)

4. Advanced Querying

• Joins: Inner, Left, Right, Full Outer.
• Aggregates: count, sum, avg, string_agg (concatenating text).
• Date/Time: Handling Timezones (Timestamptz), Intervals, and Date math.

5. Window Functions (Postgres Superpower)

• Concept: Performing calculations across rows without collapsing them (unlike GROUP BY).
• Functions: ROW_NUMBER(), RANK(), DENSE_RANK(), LEAD(), LAG().
• Frames: ROWS BETWEEN PRECEDING AND FOLLOWING.

6. Common Table Expressions (CTEs)

• Readable SQL: Using WITH clauses to organize complex logic.
• Recursive CTEs: Querying hierarchical data (e.g., finding all subordinates of a manager, or traversing a file tree).

---

Module 3: The "NoSQL" Parts & Extensions (Advanced)

7. JSONB: NoSQL inside SQL

• JSON vs. JSONB: Why Binary JSON (JSONB) is faster for indexing.
• Querying JSON: Accessing fields (->, ->>), filtering by keys (@>).
• Modifying JSON: Updating specific keys inside a JSON document without rewriting the whole row.

8. Full Text Search

• Replacing Elasticsearch for medium workloads.
• TSVector & TSQuery: converting text to searchable tokens.
• Ranking: Using ts_rank to order results by relevance.
• Fuzzy Search: Handling typos and similarities.

9. Extensions

• The Ecosystem: How to install extensions (CREATE EXTENSION).
• PostGIS: The industry standard for geospatial data (Maps, Coordinates, Distances).
• pg_trgm: Trigram matching for powerful text similarity search.

---

Module 4: Performance & Internals (Pro)

10. Indexing Strategies

• B-Tree: The default for sorting and equality.
• GIN (Generalized Inverted Index): Essential for JSONB and Full Text Search.
• Partial Indexes: Indexing only a subset of rows (e.g., WHERE status = 'active').
• Composite Indexes: Indexing multiple columns together.

11. Query Analysis

• EXPLAIN ANALYZE: Reading query plans to find bottlenecks (Sequential Scans vs. Index Scans).
• Cost Models: Understanding how the planner decides what to do.

12. Concurrency & Maintenance

• MVCC: Multi-Version Concurrency Control (How readers don't block writers).
• VACUUM: Cleaning up dead tuples (rows) to prevent bloat.
• Locks: Understanding Deadlocks and row-level locking.

---

Module 5: Programming & Administration (Expert)

13. PL/pgSQL (Server-Side Logic)

• Functions: Writing reusable logic in the database.
• Triggers: Automating actions on table changes (BEFORE INSERT, AFTER UPDATE).
• Stored Procedures: Transaction control inside scripts.

14. Security

• Roles & Users: CREATE ROLE.
• Privileges: GRANT / REVOKE on tables, schemas, and columns.
• Row Level Security (RLS): Policies that restrict which rows a user can see (Crucial for SaaS apps like Supabase).

15. DevOps & Reliability

• Backups: pg_dump (Logical) vs. Physical backups.
• Connection Pooling: Why you need PgBouncer for high-traffic apps.
• Replication: Primary-Replica architecture (Streaming Replication) for high availability.

---

Module 6: Projects & Portfolio

16. Real-World Scenarios

• Project 1 (E-commerce): Design a schema using JSONB for flexible product attributes (Color, Size, Material) while keeping Order data relational.
• Project 2 (Geo-Location): Use PostGIS to build a "Find nearest coffee shops" query system.
• Project 3 (Analytics): Build a dashboard backend using Window Functions to calculate "Month-over-Month Growth" and "Rolling Averages."
• Project 4 (Optimization): Take a slow query (10s), add 1 million rows of dummy data, and optimize it to run in under 50ms using Indexes and Explain Analyze.

---

Recommended Learning Resources

• The Docs: PostgreSQL Official Documentation (Exceptionally well-written).
• Books: "The Art of PostgreSQL" (Dimitri Fontaine), "PostgreSQL: Up and Running".
• Interactive: PGExercises.com.
• Tools: Supabase (Great for learning RLS and Postgres in the cloud).