Advanced Spatial Joins

Contents

8. Advanced Spatial Joins#

8.1. Introduction#

8.2. Learning Objectives#

8.3. Sample Datasets#

8.4. Installation#

8.5. Library Import and Configuration#

8.6. Connecting to DuckDB#

8.6.1. Loading the Spatial Extension#

8.6.2. Exploring the Database Contents#

8.7. Intersection Joins#

8.7.1. Examining the Input Tables#

8.7.2. Performing a Basic Spatial Join#

8.7.3. Scaling to All Features#

8.7.5. Pattern Summary for Point-in-Polygon Joins#

8.8. Distance Within Joins#

8.8.1. Understanding ST_DWithin Syntax#

8.8.2. Analyzing Demographics Near Transit: A Case Study#

8.9. Advanced Join#

8.10. Coordinate System Transformations#

8.10.1. Transforming Geographic to Projected Coordinates#

8.10.2. Applying the Transformation#

8.10.3. When and How to Use ST_Transform#

8.10.4. Practical Transformation Example in Joins#

8.11. Spatial Relationship Functions Reference#

8.11.1. Core Spatial Predicates#

8.11.2. Choosing the Right Predicate#

8.12. Key Takeaways#

8.13. Exercises#

8.13.1. Exercise 1: Basic Point-in-Polygon Containment Join#

8.13.2. Exercise 2: Distance-Based Proximity Join with Aggregation#

8.13.3. Exercise 3: Finding Nearest Features with Distance Calculation#

8.13.4. Exercise 4: Multi-Table Join with Complex Filtering#

8.13.5. Exercise 5: Performance Analysis with Filtering Strategies#

8.13.6. Exercise 6: Demographic Analysis Across Multiple Transit Lines#

8.13.7. Exercise 7: Coordinate System Transformation Practice#

8.13.8. Exercise 8: Transit Accessibility Scoring#