Issue Summary

When a filter query  fetch more than 500 unique insights object, the query is aborted since 500 is a hard limit. 

If this query is used in a pie chart gadget, the query will silently fails and the pie chart will display no data.  

Steps to Reproduce

1. Create a query that return more than 500 unique insight object
2. Use this query in a pie chart
3. Display the pie chart

Expected Results

The pie chart display results  

Actual Results

The pie chart is empty

Workaround

Doing multiply smaller queries in order to not hit that 500 unique insight threshold.