I have an application where dynamic points are pulled from a SQL db via an Ajax call - the points cannot live as a static map service on the server, and the SQL db from which I query is not integrated, and cannot be made to integrate, with ArcGIS Server, at least at the current moment.
The basic set-up works well - I can asynchronously retrieve the x,y points and make them available for display via a toggle button. I am creating a feature layer using a JSON feature collection/layer definition and applying a unique value renderer.
The problem is with the volume of data - I can only display a sampling of the available features... there are too many points to display at once. What I would really like to do is apply some sort of on-demand filter. The cap would remain the same; however, as the scale becomes smaller, the density of points would increase, and previously hidden points (at the larger scale) would become available.
I know we can do this for map services on the server, but what about JSON-created layers? Ideally, every time a user loads the points, a new db call would be made to retrieve fresh data as they have a high rate of change. I could reduce the refresh to a daily update if there is a way to update a static map service through an automated batch job. The complete scope of data we are talking about is tens of millions of points, although we would never show all at any scale, and would need a connection to, at the most, several tens of thousands to hundreds of thousands of points.
Any ideas would be appreciated!