supabase-vector-tile

Use MapLibre's addProtocol to visualize large PostGIS tables, by calling a custom function using the Supabase JS client.

Steps

Use the Overture CLI to download places for a bounding box.

pip install overturemaps
overturemaps download --bbox=103.570233,1.125077,104.115855,1.490957 -f geojson --type=place -o places.geojson

Use ogr2ogr:

PG_USE_COPY=true ogr2ogr -f pgdump places.sql places.geojson

Import this as the places table in a Supabase database:

psql -h aws-0-us-west-1.pooler.supabase.com -p 5432 -d postgres -U postgres.ABCD < places.sql

Create a new Postgres Function with the body from function.sql called mvt

Modify that pl/pgsql function to include only the data you need to visualize, and consider NULLing some columns at low zooms to make tiles smaller.

Edit index.html with your Supabase URL and anonymous key.

You will also need an index on your places table:

CREATE INDEX webmercator ON public.places USING gist (st_transform(wkb_geometry, 3857))