How to prevent small polygon WMS features to be hidden when zoomed out (GeoServer + OpenLayers)

Currently I'm developing a Web-GIS app where I use GeoServer 2.61 and OpenLayers 2. The map data is served from PostgreSQL+PostGIS via GeoServer (WMS).

I'm having a problem when I'm viewing polygon map. Some maps have a very little polygon feature, which do not show at certain zoom level when I zoom out (because the feature will be too small). Is there any workaround to prevent this to happen? I need to see ALL the polygon features at the lowest zoom level.

Answer

Polygon layers by default do not stay the same size when zooming further out because they represent an area. The only aspect that you will see for smaller polygons when zoomed out is just the outline. If you still want to represent the feature when zoomed far out one option would be to add a within the sld that will turn on at x scale (defining MIN and MAX scales for the polygon and point symbolizers). Refer to this Q/A for how to set this up:

Use SLD to conditionally display points or polygons based on zoom level?