6 ms·

The vector file seems really useful. I ran a query that resulted in a 1.5 GB geojson file... much too big for Leaflet. Maybe the Vector tile would be compact en

The vector file seems really useful. I ran a query that resulted in a 1.5 GB geojson file... much too big for Leaflet. Maybe the Vector tile would be compact enough? Thanks!

dbetteridge 7y ago
Yeah I know that pain. You'll need the MapboxVectorTiles plugin for leaflet but you can definitely improve the sizes by a fair bit.
mr_toad 7y ago
You could try to reduce the size with TopoJSON https://github.com/topojson/topojson-simplify https://github.com/topojson/topojson-simplify https://medium.com/@mbostock/command-line-cartography-part-1-897aa8f8ca2c https://medium.com/@mbostock/command-line-cartography-part-1...
gloflo 7y ago
Reduce the precision, 15 decimal places are useful for picometers, not a web map. Try 5-6.
- Demiurge 7y ago
  It never seems worth the effort in my testing, as you have to come up with your own loop to do the truncating, and the benefit is marginal. In this case he’d have 1.2gb file, I doubt that fixes the problem.
  - durkie 7y ago
    for what it's worth, ST_AsGeoJSON lets you specify decimal precision as an optional argument, so you at least don't have to write a truncating loop. Another good option with many polygon geometries is Base64 encoding the output of ST_AsGeobuf -- it is many times smaller than GeoJSON and still pretty easy to handle from Javascript. (Needs libprotobuf-c on the PostGIS side and geobuf.js+pbf.js on the JS side)
    - Demiurge 7y ago
      Thats cool, I should try AsGeobuf as a soft upgrade to one of the older tile GeoJSON site :)
Demiurge 7y ago
When you're doing tiles, you need to simplify to highest resolution actually discernible in that tile. So, for each zoom level, generate bbox tile bounds, and then simplify or cluster everything in each tile for the pixel resolution you want. That way you will never have 1.5GB tile. After all, all that data is wasted space if it can't be seen. I've done this for GeoJSON tiles for a long time, before the MVT tiles. The MVT tiles pack way more data though, but are not a solution to the O(n2) problem.

The vector file seems really useful. I ran a query that resulted in a 1.5 GB geojson file... much too big for Leaflet. Maybe the Vector tile would be compact enough? Thanks!

dbetteridge 7y ago

Yeah I know that pain. You'll need the MapboxVectorTiles plugin for leaflet but you can definitely improve the sizes by a fair bit.

mr_toad 7y ago

You could try to reduce the size with TopoJSON https://github.com/topojson/topojson-simplify https://github.com/topojson/topojson-simplify https://medium.com/@mbostock/command-line-cartography-part-1-897aa8f8ca2c https://medium.com/@mbostock/command-line-cartography-part-1...

gloflo 7y ago

Reduce the precision, 15 decimal places are useful for picometers, not a web map. Try 5-6.

Demiurge 7y ago
It never seems worth the effort in my testing, as you have to come up with your own loop to do the truncating, and the benefit is marginal. In this case he’d have 1.2gb file, I doubt that fixes the problem.
- durkie 7y ago
  for what it's worth, ST_AsGeoJSON lets you specify decimal precision as an optional argument, so you at least don't have to write a truncating loop. Another good option with many polygon geometries is Base64 encoding the output of ST_AsGeobuf -- it is many times smaller than GeoJSON and still pretty easy to handle from Javascript. (Needs libprotobuf-c on the PostGIS side and geobuf.js+pbf.js on the JS side)
  - Demiurge 7y ago
    Thats cool, I should try AsGeobuf as a soft upgrade to one of the older tile GeoJSON site :)

Demiurge 7y ago

When you're doing tiles, you need to simplify to highest resolution actually discernible in that tile. So, for each zoom level, generate bbox tile bounds, and then simplify or cluster everything in each tile for the pixel resolution you want. That way you will never have 1.5GB tile. After all, all that data is wasted space if it can't be seen. I've done this for GeoJSON tiles for a long time, before the MVT tiles. The MVT tiles pack way more data though, but are not a solution to the O(n2) problem.