This document outlines the current status and future direction of the SQL Engineering Handbook project.
The SQL Engineering Handbook is a production-ready learning resource for aspiring and practicing Data Analysts. We're building a comprehensive collection of 100+ real-world SQL queries with business context, optimization tips, and interview preparation.
Current Status: v1.0.0 - Core modules complete and stable
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✅ Module 1: Fundamentals (5 topics) - Basic SQL queries
- SELECT, WHERE, ORDER BY, LIMIT, ALIAS
- examples
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✅ Module 2: Aggregations (6 topics) - Data summarization
- COUNT, SUM, AVG, MIN, MAX, GROUP BY, HAVING
- examples
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✅ Module 3: Joins ( join types) - Multi-table queries
- INNER, LEFT, RIGHT, FULL OUTER, CROSS
- examples with join
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✅ Module 4: Subqueries (patterns) - simple,
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complex subqueries with examples
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✅ Module 5: CASE WHEN (patterns) - Conditional logic
- Simple CASE, Complex CASE , buisness
- examples
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✅ Module 6: CTEs ( patterns) - Query organization
- Basic, Multiple CTEs, JOIN CTEs ,
- Buisness Related examples
- 🔄 Module 7: Window Functions (6 topics) - Analytical queries
- ROW_NUMBER, RANK, DENSE_RANK, LAG/LEAD, Running Totals, PARTITION BY
- Status: 80% complete, 25+ examples ready
- Target: v1.0.1 (July 2026)
Focus: Complete Window Functions module with advanced patterns
Deliverables:
- ✅ Complete all 6 window function topics
- ✅ Add real-world analytics examples
- ✅ Include performance tuning tips
- ✅ Interview question bank for window functions
- ✅ Practice challenges and solutions
Timeline: July 2026
New Modules:
- 📋 Module 8: Query Optimization (6 topics)
- EXPLAIN/ANALYZE plans
- Index strategies
- Query refactoring patterns
- Common performance pitfalls
- Benchmark techniques
- before/after optimization examples
Focus Areas:
- Index selection and impact
- Query rewriting for performance
- Understanding execution plans
- Avoiding N+1 queries
- Batch processing vs. row-by-row
Timeline: August 2026 Estimated Content: 15-20 hours of learning material
New Modules:
- 📊 Module 9: Business Case Studies (End-to-end projects)
- Customer Segmentation Analysis
- Revenue & Sales Analytics
- Customer Lifetime Value (CLV) Calculation
- Retention & Churn Analysis
- Cohort Analysis
- Marketing Attribution Models
Focus Areas:
- Real-world business problems
- Multi-query solutions with CTEs and subqueries
- Dashboard metric calculations
- KPI definitions and formulas
- Segment-by-segment analysis
Timeline: September-October 2026 Estimated Content: 20-25 hours of learning material with real datasets
New Module:
- 🎯 Module 10: SQL Interview Questions (Expanded)
- 50+ real interview questions from top companies
- Multiple solution approaches
- Difficulty levels: Easy, Medium, Hard
- Company-specific patterns (Meta, Google, Amazon, etc.)
- Follow-up questions and variations
Focus Areas:
- Pattern recognition for interview problems
- Trade-offs between solutions
- Communication best practices
- Whiteboarding tips
- Time management during interviews
Timeline: November 2026
- PostgreSQL-specific features (JSON, Arrays, Window functions extensions)
- Advanced indexing (B-tree, Hash, GiST, GIN)
- Query tuning with
pg_stat_statements - Transaction management and concurrency control
- Materialized Views and incremental refreshes
- Database design best practices
- ETL/ELT patterns with SQL
- Data quality checks and validation
- Slowly Changing Dimensions (SCD) Type 1, 2, 3
- Fact and Dimension table design
- Slowly Changing Dimensions implementations
- Data warehousing concepts
- dbt integration patterns
- Metric definitions (semantic layer)
- Data lineage and documentation
- Testing SQL transformations
- Monitoring and alerting
- Cost optimization for cloud data warehouses
| Priority | Task | Owner | ETA | Status |
|---|---|---|---|---|
| 🔴 High | Complete Window Functions module | @theammarngp-makes | July 15 | In Progress |
| 🔴 High | Add 50+ interview questions | Community | July 31 | Not Started |
| 🟡 Medium | Create video tutorials | TBD | August 15 | Not Started |
| 🟡 Medium | Add PostgreSQL examples | Community | August 31 | Not Started |
| 🟢 Low | Performance optimization section | TBD | September 30 | Planning |
- ✅ 100+ production-ready SQL queries
- ✅ 8+ comprehensive modules
- ✅ 50+ interview questions
- ✅ 10+ real-world case studies
- ✅ 1,000+ stars on GitHub
- ✅ Active community of 100+ contributors
- ✅ 200+ SQL queries covering intermediate to advanced topics
- ✅ PostgreSQL and MySQL variants for all queries
- ✅ Video tutorial series
- ✅ Interactive practice platform integration
- ✅ Community-driven solutions and variations
- ✅ 5,000+ stars on GitHub
- Open a GitHub issue with the label
roadmap - Describe the topic and why it's valuable
- Suggest 3-5 example queries or use cases
- Tag relevant stakeholders
- Pick a module from the roadmap
- Comment on the issue or discussion
- Follow the contribution guidelines
- Work with maintainers for review
- Use discussions for feature requests
- Star the repo if you find it valuable
- Share with your network
- Contribute solutions and variations
All contributions should:
- Follow the existing structure and format
- Include business context and real-world examples
- Add explanations, common mistakes, and interview tips
- Follow SQL best practices and style guides
- Include both .md (explanations) and .sql (runnable) files
- Be tested against actual databases (MySQL, PostgreSQL, SQLite)
⚠️ Primarily MySQL-focused (PostgreSQL support coming in v1.1)⚠️ Limited performance tuning content (planned for v1.1)⚠️ No interactive practice platform yet⚠️ Limited video content (planned for v2.0)
- 📱 Mobile-friendly learning experience
- 🎥 Video walkthroughs for complex concepts
- 🧪 Interactive SQL sandbox with auto-validation
- 🔄 Spaced repetition for interview prep
- 📊 Progress tracking and personalized learning paths
- 🌍 Multi-language support
- 💬 Open a discussion in the GitHub repo
- 🐛 Report issues on the issues tab
- 📧 Contact the maintainer @theammarngp-makes
- ⭐ Star the repo to show your support
For detailed version history and feature releases, see CHANGELOG.md.
Last Updated: July 3, 2026
Part of the SQL Engineering Handbook