diff --git a/databroker/mongo_normalized.py b/databroker/mongo_normalized.py
index 90d6cb765..3ad914510 100644
--- a/databroker/mongo_normalized.py
+++ b/databroker/mongo_normalized.py
@@ -977,7 +977,7 @@ def populate_columns(keys, min_seq_num, max_seq_num):
         # their size if we need to squeeze more performance out here. But maybe
         # we can get away with never adding that complexity.
         for key, est_row_bytesize in zip(nonscalars, estimated_nonscalar_row_bytesizes):
-            page_size = TARGET_PAGE_BYTESIZE // est_row_bytesize
+            page_size = max(1, TARGET_PAGE_BYTESIZE // est_row_bytesize)
             boundaries = list(range(min_seq_num, 1 + max_seq_num, page_size))
             if boundaries[-1] != max_seq_num:
                 boundaries.append(max_seq_num)
@@ -2209,10 +2209,11 @@ def default_validate_shape(key, data, expected_shape):
     Check that data.shape == expected.shape.
 
     * If number of dimensions differ, raise BadShapeMetadata
-    * If any dimension is larger than expected, raise BadShapeMetadata.
+    * If any dimension differs by more than MAX_SIZE_DIFF, raise BadShapeMetadata.
     * If some dimensions are smaller than expected,, pad "right" edge of each
       dimension that falls short with NaN.
     """
+    MAX_SIZE_DIFF = 2
     if data.shape == expected_shape:
         return data
     if len(data.shape) != len(expected_shape):
@@ -2224,12 +2225,10 @@ def default_validate_shape(key, data, expected_shape):
         )
     # Pad at the "end" along any dimension that is too short.
     padding = []
-    trimming = []
     for actual, expected in zip(data.shape, expected_shape):
         margin = expected - actual
         # Limit how much padding or trimming we are willing to do.
-        SOMEWHAT_ARBITRARY_LIMIT_OF_WHAT_IS_REASONABLE = 2
-        if abs(margin) > SOMEWHAT_ARBITRARY_LIMIT_OF_WHAT_IS_REASONABLE:
+        if abs(margin) > MAX_SIZE_DIFF:
             raise BadShapeMetadata(
                 f"For data key {key} "
                 f"shape {data.shape} does not "
@@ -2237,19 +2236,12 @@ def default_validate_shape(key, data, expected_shape):
             )
         if margin > 0:
             padding.append((0, margin))
-            trimming.append(slice(None, None))
         elif margin < 0:
             padding.append((0, 0))
-            trimming.append(slice(None))
         else:  # margin == 0
             padding.append((0, 0))
-            trimming.append(slice(None, None))
-        # TODO Rethink this!
-        # We cannot do NaN because that does not work for integers
-        # and it is too late to change our mind about the data type.
-        padded = numpy.pad(data, padding, "edge")
-        padded_and_trimmed = padded[tuple(trimming)]
-    return padded_and_trimmed
+    padded = numpy.pad(data, padding, "edge")
+    return padded
 
 
 def build_summary(run_start_doc, run_stop_doc, stream_names):
diff --git a/databroker/tests/test_validate_shape.py b/databroker/tests/test_validate_shape.py
index 01a37df6c..df563e384 100644
--- a/databroker/tests/test_validate_shape.py
+++ b/databroker/tests/test_validate_shape.py
@@ -1,10 +1,13 @@
 from bluesky import RunEngine
 from bluesky.plans import count
-from ophyd.sim import img
+from ophyd.sim import img, DirectImage
 from tiled.client import Context, from_context
 from tiled.server.app import build_app
 
-from ..mongo_normalized import MongoAdapter
+from ..mongo_normalized import MongoAdapter, BadShapeMetadata
+
+import numpy as np
+import pytest
 
 
 def test_validate_shape(tmpdir):
@@ -29,3 +32,70 @@ def post_document(name, doc):
         assert not shapes
         client[uid]["primary"]["data"]["img"][:]
         assert shapes
+
+
+@pytest.mark.parametrize(
+    "shape,expected_shape",
+    [
+        ((10,), (11,)),
+        ((10, 20), (10, 21)),
+        ((10, 20), (10, 19)),
+        ((10, 20, 30), (10, 21, 30)),
+        ((10, 20, 30), (10, 20, 31)),
+        ((20, 20, 20, 20), (20, 21, 20, 22)),
+    ],
+)
+def test_padding(tmpdir, shape, expected_shape):
+    adapter = MongoAdapter.from_mongomock()
+
+    direct_img = DirectImage(
+        func=lambda: np.array(np.ones(shape)), name="direct", labels={"detectors"}
+    )
+    direct_img.img.name = "img"
+
+    with Context.from_app(build_app(adapter), token_cache=tmpdir) as context:
+        client = from_context(context)
+
+        def post_document(name, doc):
+            if name == "descriptor":
+                doc["data_keys"]["img"]["shape"] = expected_shape
+
+            client.post_document(name, doc)
+
+        RE = RunEngine()
+        RE.subscribe(post_document)
+        (uid,) = RE(count([direct_img]))
+        assert client[uid]["primary"]["data"]["img"][0].shape == expected_shape
+
+
+@pytest.mark.parametrize(
+    "shape,expected_shape",
+    [
+        ((10,), (11, 12)),
+        ((10, 20), (10, 200)),
+        ((20, 20, 20, 20), (20, 21, 20, 200)),
+        ((10, 20), (5, 20)),
+    ],
+)
+def test_default_validate_shape(tmpdir, shape, expected_shape):
+    adapter = MongoAdapter.from_mongomock()
+
+    direct_img = DirectImage(
+        func=lambda: np.array(np.ones(shape)), name="direct", labels={"detectors"}
+    )
+    direct_img.img.name = "img"
+
+    with Context.from_app(build_app(adapter), token_cache=tmpdir) as context:
+        client = from_context(context)
+
+        def post_document(name, doc):
+            if name == "descriptor":
+                doc["data_keys"]["img"]["shape"] = expected_shape
+
+            client.post_document(name, doc)
+
+        RE = RunEngine()
+        RE.subscribe(post_document)
+        (uid,) = RE(count([direct_img]))
+        with pytest.raises(BadShapeMetadata):
+            client[uid]["primary"]["data"]["img"][:]