Kibana 4 / Visualization Fields Subset

Trying to build a line chart visualization off a saved search. When I selected Y-Axis -> Average, I see the list of fields I can chose from. However, this appears to be a subset of all the available fields in the index. My index has quite a bit of fields (> 200). It looks like Kibana is truncating this list.

Is this known issue?

It will only display values that it can map based on the graph type you are trying to build.
eg if it was a map it'd only show fields that are mapped as geopoint.

Yeah that number of fields was a red herring. I have fields that only contain numeric values but are mapped as String so they didn’t show up. Guess I have to remap them.