Question

I have a list of 15k I need to display on a MKMapView embedded in my app.
I think this is probably too many to load at once, and I want to check if there is a standard way to do this. The XML file with the informations about the pins is stored on a webserver.

I think I have a few options, but still I’m not sure where the bottleneck would be (network, displaying many pins at once, loading the pins on the map the first time, etc):

• Parse the whole xml file and add all the annotations. Force the user zoom so you can’t see too many pins together

• Parse the whole xml file and add all the annotations. Use a library for grouping the Pins.

• Load only the top 50 pins in the area the user is currently in. Everytime the position is updated call a script on the webserver that only serves 50 positions based on map latitude-longitute and zooming.

• Cache everything in coredata and do the same as the previous point.

Any considerations about performances I should do? Any other solutions? Will these perform well enough?

Thanks!

Answer 1

The bottleneck will be displaying that many pins at one time on the map. You shouldn’t display more than around 500 at one time. Zoomed in might be OK, but zoomed out will affect performance and map visibility.

Here’s a library that will do clustering for you:

http://applidium.com/en/news/too_many_pins_on_your_map/