Filtering on phone field, ph_home_raw, exceeds query size limitation

Summary

Why does filtering on ph_home_raw analyze so many rows compared to ph_home

Content

When I filter on ph_home, the Analyzer tells me that the estimated number of analyzed rows is 6. When I filter on ph_home_raw field, the estimated number of analyzed rows is over 2.4million. What is the reason for this huge increase, besides the field not being indexed?

The main problem is that we are unable to perform contact searches on this ph_home_raw field because this query is over the threshold for the Operational Database. On the other hand, filtering on the indexed phone field,