Made the search filter have a calculated threshold with a lower threshold for small query strings and a higher threshold for large query strings.

starfields_drf_generics/filters.py

@@ -14,6 +14,15 @@ from django.db.models.functions import Concat
 
 # TODO the dev pages are not done
 
+def calculate_threshold(query, min_threshold, max_threshold):
+    query_threshold = len(query)/300
+    if query_threshold < min_threshold:
+        return min_threshold
+    if max_threshold < query_threshold:
+        return max_threshold
+    return query_threshold
+
+
 def search_smart_split(search_terms):
     """generator that first splits string by spaces, leaving quoted phrases together,
     then it splits non-quoted phrases by commas.
@@ -516,6 +525,7 @@ class TrigramSearchFilter(BaseFilterBackend):
         try:
             # Attempt postgresql's full text search
             from django.contrib.postgres.search import TrigramStrictWordSimilarity
+            threshold = calculate_threshold(query, 0.02, 0.12)
             queryset = queryset.annotate(
                             search_field=Concat(
                                 *search_fields,
@@ -523,7 +533,7 @@ class TrigramSearchFilter(BaseFilterBackend):
                                 )).annotate(
                         similarity=TrigramStrictWordSimilarity(
                             'search_field', query)
-                    ).filter(similarity__gt=0.05)
+                    ).filter(similarity__gt=threshold)
 
         except ImportError:
             # Perform very simple sqlite compatible search