From 7ed59b412f00dfd105b9c4b7444dc5714764ec93 Mon Sep 17 00:00:00 2001
From: brimoor <brimoor@umich.edu>
Date: Thu, 16 Jan 2025 20:37:50 -0500
Subject: [PATCH 1/2] use estimated document count when possible

---
 fiftyone/core/collections.py | 14 ++++++++++++++
 fiftyone/core/dataset.py     |  9 +++++++++
 2 files changed, 23 insertions(+)

diff --git a/fiftyone/core/collections.py b/fiftyone/core/collections.py
index c8314b64e92..65629960c07 100644
--- a/fiftyone/core/collections.py
+++ b/fiftyone/core/collections.py
@@ -7726,6 +7726,20 @@ def count(self, field_or_expr=None, expr=None, safe=False):
         Returns:
             the count
         """
+
+        # Optimization: use estimated document count when possible
+        if (
+            isinstance(self, fod.Dataset)
+            and expr is None
+            and (
+                field_or_expr is None
+                or (field_or_expr == "frames" and self._has_frame_fields())
+            )
+        ):
+            frames = field_or_expr == "frames"
+            # pylint: disable=no-member
+            return self._estimated_count(frames=frames)
+
         make = lambda field_or_expr: foa.Count(
             field_or_expr, expr=expr, safe=safe
         )
diff --git a/fiftyone/core/dataset.py b/fiftyone/core/dataset.py
index c385a7e66bb..3213402da1c 100644
--- a/fiftyone/core/dataset.py
+++ b/fiftyone/core/dataset.py
@@ -360,6 +360,15 @@ def __deepcopy__(self, memo):
     def __len__(self):
         return self.count()
 
+    def _estimated_count(self, frames=False):
+        if frames:
+            if self._frame_collection is None:
+                return None
+
+            return self._frame_collection.estimated_document_count()
+
+        return self._sample_collection.estimated_document_count()
+
     def __getitem__(self, id_filepath_slice):
         if isinstance(id_filepath_slice, numbers.Integral):
             raise ValueError(

From d11868cb1e37fa2f6a06264a3895cc728879f131 Mon Sep 17 00:00:00 2001
From: brimoor <brimoor@umich.edu>
Date: Fri, 17 Jan 2025 23:27:32 -0500
Subject: [PATCH 2/2] support grouped collections

---
 fiftyone/core/collections.py | 30 ++++++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/fiftyone/core/collections.py b/fiftyone/core/collections.py
index 65629960c07..3170dbf74bb 100644
--- a/fiftyone/core/collections.py
+++ b/fiftyone/core/collections.py
@@ -7728,17 +7728,19 @@ def count(self, field_or_expr=None, expr=None, safe=False):
         """
 
         # Optimization: use estimated document count when possible
-        if (
-            isinstance(self, fod.Dataset)
-            and expr is None
+        if self._is_full_collection() and (
+            expr is None
             and (
                 field_or_expr is None
-                or (field_or_expr == "frames" and self._has_frame_fields())
+                or (
+                    etau.is_str(field_or_expr)
+                    and field_or_expr == "frames"
+                    and self._has_frame_fields()
+                )
             )
         ):
             frames = field_or_expr == "frames"
-            # pylint: disable=no-member
-            return self._estimated_count(frames=frames)
+            return self._dataset._estimated_count(frames=frames)
 
         make = lambda field_or_expr: foa.Count(
             field_or_expr, expr=expr, safe=safe
@@ -10616,6 +10618,22 @@ def _has_frame_fields(self):
     def _handle_id_fields(self, field_name):
         return _handle_id_fields(self, field_name)
 
+    def _is_full_collection(self):
+        if isinstance(self, fod.Dataset) and self.media_type != fom.GROUP:
+            return True
+
+        # pylint:disable=no-member
+        if (
+            isinstance(self, fov.DatasetView)
+            and self._dataset.media_type == fom.GROUP
+            and len(self._stages) == 1
+            and isinstance(self._stages[0], fos.SelectGroupSlices)
+            and self._pipeline() == []
+        ):
+            return True
+
+        return False
+
     def _is_label_field(self, field_name, label_type_or_types):
         try:
             label_type = self._get_label_field_type(field_name)