[postgis-users] PostGIS heatmap generation

[Paul Norman]

> Sent: Tuesday, March 18, 2014 12:41 AM
> To: PostGIS Users Discussion
> Subject: Re: [postgis-users] PostGIS heatmap generation
> 
> Pre-aggregation would surely help, big problem being amount
> of records that need to be read from disk. You could also look
> at postgis raster as the aggregation type.

Any suggestions on how to use postgis raster for aggregation?

To aggregate with SQL I was thinking I'd use something like this:

CREATE TABLE agg1 AS 
  SELECT 
    COUNT(*), ST_SnapToGrid(ST_Transform(geom, 3857), 10, 10),
    date_trunc('hour', tstamp)
  FROM points
  GROUP BY ST_SnapToGrid(ST_Transform(geom, 3857), 10, 10),
    date_trunc('hour', tstamp);

Of course, I need to then render it with something