diff --git a/src/daft-logical-plan/src/builder.rs b/src/daft-logical-plan/src/builder.rs
index ece988e08c..d82186c60e 100644
--- a/src/daft-logical-plan/src/builder.rs
+++ b/src/daft-logical-plan/src/builder.rs
@@ -464,7 +464,8 @@ impl LogicalPlanBuilder {
     }
     pub fn union(&self, other: &Self, is_all: bool) -> DaftResult<Self> {
         let logical_plan: LogicalPlan =
-            ops::Union::new(self.plan.clone(), other.plan.clone(), is_all).to_logical_plan()?;
+            ops::Union::try_new(self.plan.clone(), other.plan.clone(), is_all)?
+                .to_logical_plan()?;
         Ok(self.with_new_plan(logical_plan))
     }
 
diff --git a/src/daft-logical-plan/src/logical_plan.rs b/src/daft-logical-plan/src/logical_plan.rs
index f1fc3bbd8c..71f6d5bc96 100644
--- a/src/daft-logical-plan/src/logical_plan.rs
+++ b/src/daft-logical-plan/src/logical_plan.rs
@@ -279,7 +279,7 @@ impl LogicalPlan {
                 Self::Source(_) => panic!("Source nodes don't have children, with_new_children() should never be called for Source ops"),
                 Self::Concat(_) => Self::Concat(Concat::try_new(input1.clone(), input2.clone()).unwrap()),
                 Self::Intersect(inner) => Self::Intersect(Intersect::try_new(input1.clone(), input2.clone(), inner.is_all).unwrap()),
-                Self::Union(inner) => Self::Union(Union::new(input1.clone(), input2.clone(), inner.is_all)),
+                Self::Union(inner) => Self::Union(Union::try_new(input1.clone(), input2.clone(), inner.is_all).unwrap()),
                 Self::Join(Join { left_on, right_on, null_equals_nulls, join_type, join_strategy, .. }) => Self::Join(Join::try_new(
                     input1.clone(),
                     input2.clone(),
diff --git a/src/daft-logical-plan/src/ops/set_operations.rs b/src/daft-logical-plan/src/ops/set_operations.rs
index 9a37cfebfa..017104f226 100644
--- a/src/daft-logical-plan/src/ops/set_operations.rs
+++ b/src/daft-logical-plan/src/ops/set_operations.rs
@@ -128,8 +128,23 @@ impl Union {
     /// > select * from t0 union select * from t1;
     /// ```
     /// This is valid in Union, but not in Concat
-    pub(crate) fn new(lhs: Arc<LogicalPlan>, rhs: Arc<LogicalPlan>, is_all: bool) -> Self {
-        Self { lhs, rhs, is_all }
+    pub(crate) fn try_new(
+        lhs: Arc<LogicalPlan>,
+        rhs: Arc<LogicalPlan>,
+        is_all: bool,
+    ) -> logical_plan::Result<Self> {
+        if lhs.schema().len() != rhs.schema().len() {
+            return Err(DaftError::SchemaMismatch(format!(
+                "Both plans must have the same num of fields to union, \
+                but got[lhs: {} v.s rhs: {}], lhs schema: {}, rhs schema: {}",
+                lhs.schema().len(),
+                rhs.schema().len(),
+                lhs.schema(),
+                rhs.schema()
+            )))
+            .context(CreationSnafu);
+        }
+        Ok(Self { lhs, rhs, is_all })
     }
 
     /// union could be represented as a concat + distinct
diff --git a/src/daft-logical-plan/src/optimization/rules/push_down_projection.rs b/src/daft-logical-plan/src/optimization/rules/push_down_projection.rs
index e2a237d0fd..5451106d2d 100644
--- a/src/daft-logical-plan/src/optimization/rules/push_down_projection.rs
+++ b/src/daft-logical-plan/src/optimization/rules/push_down_projection.rs
@@ -417,6 +417,11 @@ impl PushDownProjection {
                 Ok(new_plan)
             }
             LogicalPlan::Union(union) => {
+                if !union.is_all {
+                    // can not push down past a DISTINCT
+                    return Ok(Transformed::no(plan));
+                }
+
                 // Get required columns from projection and upstream.
                 let combined_dependencies = plan
                     .required_columns()
diff --git a/src/daft-sql/src/planner.rs b/src/daft-sql/src/planner.rs
index 3aeb60768f..1dbf6512a2 100644
--- a/src/daft-sql/src/planner.rs
+++ b/src/daft-sql/src/planner.rs
@@ -236,7 +236,7 @@ impl SQLPlanner {
                         return left.union(&right, true).map_err(|e| e.into());
                     }
 
-                    (Union, SetQuantifier::None) => {
+                    (Union, SetQuantifier::None | SetQuantifier::Distinct) => {
                         let left = self.plan_query(&make_query(left))?;
                         let right = self.plan_query(&make_query(right))?;
                         return left.union(&right, false).map_err(|e| e.into());
@@ -247,7 +247,7 @@ impl SQLPlanner {
                         let right = self.plan_query(&make_query(right))?;
                         return left.intersect(&right, true).map_err(|e| e.into());
                     }
-                    (Intersect, SetQuantifier::None) => {
+                    (Intersect, SetQuantifier::None | SetQuantifier::Distinct) => {
                         let left = self.plan_query(&make_query(left))?;
                         let right = self.plan_query(&make_query(right))?;
                         return left.intersect(&right, false).map_err(|e| e.into());