SNOW-3156942: Add support for the ARRAY_UNION_AGG function

CHANGELOG.md

@@ -6,6 +6,8 @@
 
 #### New Features
 
+- Added support for the `array_union_agg` function in the `snowflake.snowpark.functions` module.
+
 #### Bug Fixes
 
 - Fixed a bug where `Session.udf.register_from_file` did not properly process the `strict` and `secure` parameters.

docs/source/snowpark/functions.rst

@@ -67,6 +67,7 @@ Functions
     array_sort
     array_to_string
     array_union
+    array_union_agg
     array_unique_agg
     arrays_overlap
     arrays_zip

src/snowflake/snowpark/functions.py

@@ -7450,6 +7450,38 @@ def array_to_string(
     return _call_function("array_to_string", a, s, _emit_ast=_emit_ast)
 
 
+@publicapi
+def array_union_agg(col: ColumnOrName, _emit_ast: bool = True) -> Column:
+    """Returns an ARRAY that contains the union of the distinct values from the input
+    arrays in the specified column.
+
+    The values in the returned ARRAY are in no particular order, and the order is not
+    deterministic. The function ignores NULL values in the column and in arrays in the
+    column. If the column contains only NULL values or the input is empty, the function
+    returns an empty ARRAY.
+
+    Args:
+        col: A :class:`Column` object or column name containing arrays with distinct values.
+
+    Example::
+        >>> df = session.create_dataframe([[[1, 1, 2]], [[1, 2, 3]]], schema=["a"])
+        >>> df.select(array_union_agg("a").alias("result")).show()
+        ------------
+        |"RESULT"  |
+        ------------
+        |[         |
+        |  1,      |
+        |  1,      |
+        |  2,      |
+        |  3       |
+        |]         |
+        ------------
+        <BLANKLINE>
+    """
+    c = _to_col_if_str(col, "array_union_agg")
+    return _call_function("array_union_agg", c, _emit_ast=_emit_ast)
+
+
 @publicapi
 def array_unique_agg(col: ColumnOrName, _emit_ast: bool = True) -> Column:
     """Returns a Column containing the distinct values in the specified column col.