Impact of "ResponseGeometry" / "geometryOptions" (bandwidth)

[Bernd Welter]

Cheers,

as you may know we offer to handle different geometry styles in the context of xServers:
- xServer1 : CallerContextProperty->ResponseGeometry
- xServer2 : RequestBase.geometryOptions

The style you use within a transaction may have a significant impact on the message size and therefore on the performance (depending on the available bandwidth).

Here's an example of a route (xServer2.xRoute) from Barcelona to Warszaw with a distance of more than 2300km:

Code: Select all

{
  "waypoints": [
    {
      "$type": "OffRoadWaypoint",
      "location": {
        "offRoadCoordinate": {
          "x": 2.1700100683,
          "y": 41.388038574
        }
      }
    },
    {
      "$type": "OffRoadWaypoint",
      "location": {
        "offRoadCoordinate": {
          "x": 21.010370204,
          "y": 52.235599501
        }
      }
    }
  ],
  "resultFields": {
    "polyline": true
  },
  "geometryOptions":
  {
    "responseGeometryTypes":["WKB","PLAIN","WKT","KML","GEOJSON"]
  }
}

So within this request I ask for the polygon line in 5 different styles. From a logical perspective the content of these 5 response elements is equal. There's no loss of quality!
Now here are the sizes of those elements:

Style	Size	Relative to PLAIN
PLAIN	564'324	100%
WKB	336'429	60%
WKT	422'382	75%
KML	406'921	72%
geoJson	439'520	78%

Obviously the PLAIN style is the most bandwith consuming one. Especially for long distance routes this makes a big difference.

The benefit of the PLAIN style is that you can easily access any element of such a geometry even without the need for a specific geometry library.
The other styles may save bandwith but you may need some additional geometry frameworks to have full access to all the elements of such a geometry.

Nowadays such libraries are quite common. Even the mapping frameworks you use support them.
So if you can request geometries in WKB and then transfer them on client side in memory you may gain performance.

Best regards,
Bernd