feat(api): add distinct to Intersection and Difference operations

Author: cpcloud

ibis/expr/operations/relations.py

@@ -254,13 +254,14 @@ def __init__(self, left, right, by, predicates, **kwargs):
 class SetOp(TableNode, sch.HasSchema):
     left = rlz.table
     right = rlz.table
+    distinct = rlz.optional(rlz.instance_of(bool), default=False)
 
-    def __init__(self, left, right, **kwargs):
+    def __init__(self, left, right, distinct: bool, **kwargs):
         if not left.schema().equals(right.schema()):
             raise com.RelationError(
                 'Table schemas must be equal for set operations'
             )
-        super().__init__(left=left, right=right, **kwargs)
+        super().__init__(left=left, right=right, distinct=distinct, **kwargs)
 
     @property
     def schema(self):
@@ -272,7 +273,7 @@ def blocks(self):
 
 @public
 class Union(SetOp):
-    distinct = rlz.optional(rlz.instance_of(bool), default=False)
+    pass
 
 
 @public

ibis/expr/types/relations.py

@@ -292,7 +292,7 @@ def view(self) -> Table:
 
         return ops.SelfReference(self).to_expr()
 
-    def difference(self, right: Table) -> Table:
+    def difference(self, right: Table, distinct: bool = True) -> Table:
         """Compute the set difference of two table expressions.
 
         The input tables must have identical schemas.
@@ -301,6 +301,8 @@ def difference(self, right: Table) -> Table:
         ----------
         right
             Table expression
+        distinct
+            Only diff distinct rows not occurring in the calling table
 
         Returns
         -------
@@ -309,7 +311,7 @@ def difference(self, right: Table) -> Table:
         """
         from ibis.expr import operations as ops
 
-        return ops.Difference(self, right).to_expr()
+        return ops.Difference(self, right, distinct=distinct).to_expr()
 
     def aggregate(
         self,
@@ -455,8 +457,7 @@ def union(
         right
             Table expression
         distinct
-            Only union distinct rows not occurring in the calling table (this
-            can be very expensive, be careful)
+            Only union distinct rows not occurring in the calling table
 
         Returns
         -------
@@ -467,7 +468,7 @@ def union(
 
         return ops.Union(self, right, distinct=distinct).to_expr()
 
-    def intersect(self, right: Table) -> Table:
+    def intersect(self, right: Table, distinct: bool = True) -> Table:
         """Compute the set intersection of two table expressions.
 
         The input tables must have identical schemas.
@@ -476,6 +477,8 @@ def intersect(self, right: Table) -> Table:
         ----------
         right
             Table expression
+        distinct
+            Only intersect distinct rows not occurring in the calling table
 
         Returns
         -------
@@ -484,7 +487,7 @@ def intersect(self, right: Table) -> Table:
         """
         from ibis.expr import operations as ops
 
-        return ops.Intersection(self, right).to_expr()
+        return ops.Intersection(self, right, distinct=distinct).to_expr()
 
     def to_array(self) -> ir.Column:
         """View a single column table as an array.