Google Maps V3: Only show markers in viewport - Clear markers issue

Question

I like to create a map with Google Maps that can handle large amounts of markers (over 10.000). To not slow down the map I\'ve created a XML-file that only outputs the markers t

Answer 1

This article goes through it pretty nicely: Dynamically loading thousands of markers in Google Maps

• dynamically load markers until we reach a threshold
• keep a hashtable of markers that have already been added
• after the threshold has been reached, remove markers that aren’t currently within the viewport
• remove all markers from the map when the user has zoomed out, and don’t load any markers until the user zooms back to a reasonable level