Spatial SQL with PostGIS and SedonaDB

Twenty-five lessons, written against a live PostGIS 3.6 cluster and a planet-scale OSM import. Every query on these pages is one you can run yourself.

The first 4 lessons are open. The rest continue in the app.

#	Lesson
1	Prerequisites: Joins and Big O
2	Where Your SQL Runs
3	Geometry Is a Type, Not Two Numbers
4	Degrees Are Not Metres
5	Reading a Schema You Did Not Write	Sign in to read
6	Filtering, Casting and NULL Discipline	Sign in to read
7	Aggregation and the Spatial Aggregates	Sign in to read
8	CTEs and the Shape of a Readable Query	Sign in to read
9	Window Functions Over Spatial Measures	Sign in to read
10	Predicates and the DE-9IM Family	Sign in to read
11	The && Operator and What an Index Can Answer	Sign in to read
12	ST_DWithin, ST_Distance and the KNN Operator	Sign in to read
13	Spatial Joins and LATERAL Nearest-Neighbour	Sign in to read
14	Constructors, Accessors and Editors	Sign in to read
15	Simplification, Tolerance and Broken Topology	Sign in to read
16	Invalid, Empty and NULL Are Three Different Things	Sign in to read
17	Querying the Feature Store	Sign in to read
18	Raw OSM Tags as jsonb	Sign in to read
19	H3 Hex Binning, Server-Side	Sign in to read
20	SedonaDB: When the Table Is a File	Sign in to read
21	Choosing an Engine, and Porting a Query	Sign in to read
22	Why Your Query Is Slow	Sign in to read
23	From Query to Map Layer	Sign in to read
24	Reading What the Assistant Wrote	Sign in to read
25	What This Cluster Cannot Do Yet	Sign in to read

Open the lessons in the app

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