postgis-spatial-sql

Invoke whenever spatial SQL or its execution backend is the decision: PostGIS, DuckDB Spatial, SpatiaLite, ST_* functions, recurring spatial joins, concurrent/growing workloads, or large GeoParquet queries. Covers backend selection, schemas, GiST/BRIN indexes, KNN, geometry versus geography, correctness benchmarks, and EXPLAIN optimization. Use PostGIS for managed concurrent services and embedded engines for bounded…