diff --git a/CHANGELOG.md b/CHANGELOG.md
index de5c8ca..b7016fc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 
+## [0.7.2] - 2026-07-15
+
+### Removed
+
+- The `POST /v1/files` fallback in `upload_parquet()`. Presigned upload sessions (`POST /v1/uploads`) are now required; a server that responds 501 raises a clear `RuntimeError` instead of silently falling back to the full-file-in-memory upload path.
+
 ## [0.7.1] - 2026-07-15
 
 ### Changed
diff --git a/hotdata_framework/client.py b/hotdata_framework/client.py
index 9a3ef82..543e0f8 100644
--- a/hotdata_framework/client.py
+++ b/hotdata_framework/client.py
@@ -321,7 +321,12 @@ def upload_parquet(self, path: str) -> str:
             )
         except ApiException as e:
             if e.status == 501:
-                return self._upload_parquet_post(path)
+                raise RuntimeError(
+                    "the server does not support presigned uploads (HTTP 501); "
+                    "managed table loads require a storage backend that can issue "
+                    "presigned URLs (the POST /v1/files fallback was removed in "
+                    "hotdata-framework 0.7.2)"
+                ) from e
             raise RuntimeError(api_error_message(e)) from e
         http = urllib3.PoolManager()
         parts: list[FinalizeUploadPart] | None = None
@@ -374,19 +379,6 @@ def upload_parquet(self, path: str) -> str:
             raise RuntimeError(api_error_message(e)) from e
         return finalized.upload_id
 
-    def _upload_parquet_post(self, path: str) -> str:
-        """Fallback for storage backends that do not support presigned URLs (501)."""
-        with open(path, "rb") as f:
-            data = f.read()
-        try:
-            uploaded = self.uploads().upload_file(
-                data,
-                _content_type="application/octet-stream",
-            )
-        except ApiException as e:
-            raise RuntimeError(api_error_message(e)) from e
-        return uploaded.id
-
     def load_managed_table(
         self,
         database: str,
diff --git a/pyproject.toml b/pyproject.toml
index 7741379..7cf5cef 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "hotdata-framework"
-version = "0.7.1"
+version = "0.7.2"
 description = "Python framework for building Hotdata integrations: workspace/session runtime, query execution, and managed databases"
 readme = "README.md"
 requires-python = ">=3.10"
diff --git a/tests/test_databases.py b/tests/test_databases.py
index 2a5cc33..118e318 100644
--- a/tests/test_databases.py
+++ b/tests/test_databases.py
@@ -278,9 +278,8 @@ def test_upload_parquet_single_put():
     assert call_args.args[1] == "https://s/put"
 
 
-def test_upload_parquet_fallback_on_501():
+def test_upload_parquet_raises_on_501():
     client = _client()
-    uploaded = SimpleNamespace(id="upl_post")
 
     with (
         patch("builtins.open", mock_open(read_data=b"PAR1")),
@@ -289,11 +288,50 @@ def test_upload_parquet_fallback_on_501():
     ):
         err = ApiException(status=501)
         uploads.return_value.create_upload_session_handler.side_effect = err
-        uploads.return_value.upload_file.return_value = uploaded
 
-        upload_id = client.upload_parquet("/tmp/data.parquet")
+        with pytest.raises(RuntimeError, match="presigned uploads"):
+            client.upload_parquet("/tmp/data.parquet")
+
+    uploads.return_value.upload_file.assert_not_called()
+
+
+def test_upload_parquet_multipart_reads_are_part_size_bounded():
+    """The OOM fix: multipart mode must never read more than part_size at once."""
+    client = _client()
+    part_size = 5
+    data = b"PAR1" + b"\x00" * 9  # 13 bytes -> parts of 5, 5, 3
+    read_sizes: list[int] = []
+
+    class _TrackingFile(io.BytesIO):
+        def read(self, n=-1):
+            read_sizes.append(n)
+            return super().read(n)
+
+    bio = _TrackingFile(data)
+    handle = MagicMock()
+    handle.__enter__ = lambda s: bio
+    handle.__exit__ = MagicMock(return_value=False)
+    session = _session(
+        "multipart", part_size=part_size, part_urls=["https://s/1", "https://s/2", "https://s/3"]
+    )
+    finalized = SimpleNamespace(upload_id="upl_final")
+
+    with (
+        patch("builtins.open", MagicMock(return_value=handle)),
+        patch("os.path.getsize", return_value=len(data)),
+        patch.object(client, "uploads") as uploads,
+        patch("hotdata_framework.client.urllib3.PoolManager") as MockPool,
+    ):
+        pool = MockPool.return_value
+        pool.request.return_value = _http_resp()
+        pool.clear.return_value = None
+        uploads.return_value.create_upload_session_handler.return_value = session
+        uploads.return_value.finalize_upload_handler.return_value = finalized
+
+        client.upload_parquet("/tmp/data.parquet")
 
-    assert upload_id == "upl_post"
+    assert read_sizes, "expected chunked reads"
+    assert all(n == part_size for n in read_sizes)
 
 
 def test_load_managed_table_with_upload_id():
diff --git a/uv.lock b/uv.lock
index a965abb..d9bc915 100644
--- a/uv.lock
+++ b/uv.lock
@@ -101,7 +101,7 @@ wheels = [
 
 [[package]]
 name = "hotdata-framework"
-version = "0.7.1"
+version = "0.7.2"
 source = { editable = "." }
 dependencies = [
     { name = "hotdata" },