feat(duckdb): implement arbitrary first and last aggregation

ibis-project · May 23, 2022 · 8a500bc · 8a500bc
1 parent 5c96498
commit 8a500bc
Show file tree

Hide file tree

Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/ibis/backends/duckdb/registry.py b/ibis/backends/duckdb/registry.py
@@ -159,6 +159,12 @@ def _strftime(t, expr):
     )
 
 
+def _arbitrary(t, expr):
+    if (how := expr.op().how) == "heavy":
+        raise ValueError(f"how={how!r} not supported in the DuckDB backend")
+    return t._reduction(getattr(sa.func, how), expr)
+
+
 operation_registry.update(
     {
         ops.ArrayColumn: _array_column,
@@ -187,6 +193,7 @@ def _strftime(t, expr):
         ),
         ops.HLLCardinality: reduction(sa.func.approx_count_distinct),
         ops.Strftime: _strftime,
+        ops.Arbitrary: _arbitrary,
     }
 )
 

diff --git a/ibis/backends/tests/test_aggregation.py b/ibis/backends/tests/test_aggregation.py
@@ -238,15 +238,15 @@ def test_aggregate_grouped(
             lambda t, where: t.double_col[where].iloc[0],
             id='arbitrary_first',
             marks=pytest.mark.notimpl(
-                ['impala', 'postgres', 'mysql', 'sqlite', 'duckdb']
+                ['impala', 'postgres', 'mysql', 'sqlite']
             ),
         ),
         param(
             lambda t, where: t.double_col.arbitrary(how='last', where=where),
             lambda t, where: t.double_col[where].iloc[-1],
             id='arbitrary_last',
             marks=pytest.mark.notimpl(
-                ['impala', 'postgres', 'mysql', 'sqlite', 'duckdb']
+                ['impala', 'postgres', 'mysql', 'sqlite']
             ),
         ),
         param(