feat: create a separate OrderingModePartialPreviewWarning for more fine-grained warning filters (#879)

Author: tswast

bigframes/exceptions.py

@@ -47,6 +47,10 @@ class NullIndexError(ValueError):
     """Object has no index."""
 
 
+class OrderingModePartialPreviewWarning(PreviewWarning):
+    """Ordering mode 'partial' is in preview."""
+
+
 class OrderRequiredError(ValueError):
     """Operation requires total row ordering to be enabled."""
 

bigframes/session/__init__.py

@@ -302,7 +302,7 @@ def __init__(
         if not self._strictly_ordered:
             warnings.warn(
                 "Partial ordering mode is a preview feature and is subject to change.",
-                bigframes.exceptions.PreviewWarning,
+                bigframes.exceptions.OrderingModePartialPreviewWarning,
             )
 
         # Sequential index needs total ordering to generate, so use null index with unstrict ordering.