What is the maximum number of vertices for polygons and polylines (including multipart) in PostGIS?
The only link I could find about this is a post on the discussion group tittled,
What is maximum limit(max number of coordinates) for a LineString? where it is mentioned that
It's a 32bit integer, so theoretically you should be able to have up to 4,294,967,295 vertices per line.
This is correct, though the npoints counter is a signed integer (oh well), so you can "only" get 2 billion vertices in.
I would believe that the same limit would hold for a polygon.
Your question however raises more questions. What exactly are you trying to do where you would be concerned about the limit of vertices in a polygon? If you are indeed running into this limit, then you are definitely doing something wrong.