[WIP][ray] Ray merge into

paimon-python/dev/requirements-dev.txt

@@ -21,8 +21,9 @@
 duckdb==1.3.2
 flake8==4.0.1
 pytest~=7.0
-# Ray: 2.48+ has no wheel for Python 3.8; use 2.10.0 on 3.8, 2.48.0 on 3.9+
-ray>=2.10.0
+# merge_into needs Dataset.join (added in Ray 2.50). Python 3.8 has no 2.50 wheel.
+ray>=2.10.0; python_version < "3.9"
+ray>=2.50.0; python_version >= "3.9"
 requests
 parameterized
 # Vortex 0.71.0 regresses native predicate pushdown on single-row files.

paimon-python/pypaimon/ray/__init__.py

@@ -16,5 +16,16 @@
 # under the License.
 
 from pypaimon.ray.ray_paimon import read_paimon, write_paimon
+from pypaimon.ray.data_evolution_merge_into import (
+    WhenMatched,
+    WhenNotMatched,
+    merge_into,
+)
 
-__all__ = ["read_paimon", "write_paimon"]
+__all__ = [
+    "read_paimon",
+    "write_paimon",
+    "merge_into",
+    "WhenMatched",
+    "WhenNotMatched",
+]