diff --git a/datafusion/core/src/physical_plan/aggregates/row_hash2.rs b/datafusion/core/src/physical_plan/aggregates/row_hash2.rs
index 0b6862faace7..345d0c2be507 100644
--- a/datafusion/core/src/physical_plan/aggregates/row_hash2.rs
+++ b/datafusion/core/src/physical_plan/aggregates/row_hash2.rs
@@ -463,7 +463,7 @@ impl GroupedHashAggregateStream2 {
                     AggregateMode::Partial | AggregateMode::Single => {
                         acc.update_batch(
                             values,
-                            &group_indices,
+                            group_indices,
                             opt_filter,
                             total_num_groups,
                         )?;
@@ -473,7 +473,7 @@ impl GroupedHashAggregateStream2 {
                         // use merge
                         acc.merge_batch(
                             values,
-                            &group_indices,
+                            group_indices,
                             opt_filter,
                             total_num_groups,
                         )?;
@@ -501,7 +501,7 @@ impl GroupedHashAggregateStream2 {
         }
 
         // First output rows are the groups
-        let groups_rows = self.group_values.iter().map(|owned_row| owned_row);
+        let groups_rows = self.group_values.iter();
 
         let mut output: Vec<ArrayRef> = self.row_converter.convert_rows(groups_rows)?;
 
diff --git a/datafusion/physical-expr/src/aggregate/average.rs b/datafusion/physical-expr/src/aggregate/average.rs
index bf553f4c6507..3e335e5c032c 100644
--- a/datafusion/physical-expr/src/aggregate/average.rs
+++ b/datafusion/physical-expr/src/aggregate/average.rs
@@ -182,20 +182,19 @@ impl AggregateExpr for Avg {
     fn groups_accumulator_supported(&self) -> bool {
         use DataType::*;
 
-        match &self.sum_data_type {
-            Int8
-            | Int16
-            | Int32
-            | Int64
-            | UInt8
-            | UInt16
-            | UInt32
-            | UInt64
-            | Float32
-            | Float64
-            | Decimal128(_, _) => true,
-            _ => false,
-        }
+        matches!(
+            &self.sum_data_type,
+            Int8 | Int16
+                | Int32
+                | Int64
+                | UInt8
+                | UInt16
+                | UInt32
+                | UInt64
+                | Float32
+                | Float64
+                | Decimal128(_, _)
+        )
     }
 
     fn create_groups_accumulator(&self) -> Result<Box<dyn GroupsAccumulator>> {
diff --git a/datafusion/physical-expr/src/aggregate/groups_accumulator/adapter.rs b/datafusion/physical-expr/src/aggregate/groups_accumulator/adapter.rs
index 5961256be924..aae2a91a7d04 100644
--- a/datafusion/physical-expr/src/aggregate/groups_accumulator/adapter.rs
+++ b/datafusion/physical-expr/src/aggregate/groups_accumulator/adapter.rs
@@ -203,12 +203,12 @@ impl GroupsAccumulatorAdapter {
         // RecordBatch(es)
         let iter = groups_with_rows.iter().zip(offsets.windows(2));
 
-        for (group_idx, offsets) in iter {
-            let state = &mut self.states[*group_idx as usize];
+        for (&group_idx, offsets) in iter {
+            let state = &mut self.states[group_idx];
             let size_pre = state.size();
 
             let values_to_accumulate =
-                slice_and_maybe_filter(&values, opt_filter.as_ref(), &offsets)?;
+                slice_and_maybe_filter(&values, opt_filter.as_ref(), offsets)?;
             (f)(state.accumulator.as_mut(), &values_to_accumulate)?;
 
             // clear out the state
@@ -267,7 +267,7 @@ impl GroupsAccumulator for GroupsAccumulatorAdapter {
 
         for state in states {
             let accumulator_state = state.accumulator.state()?;
-            results.resize_with(accumulator_state.len(), || vec![]);
+            results.resize_with(accumulator_state.len(), Vec::new);
             for (idx, state_val) in accumulator_state.into_iter().enumerate() {
                 results[idx].push(state_val);
             }
@@ -276,7 +276,7 @@ impl GroupsAccumulator for GroupsAccumulatorAdapter {
         // create an array for each intermediate column
         let arrays = results
             .into_iter()
-            .map(|state| ScalarValue::iter_to_array(state))
+            .map(ScalarValue::iter_to_array)
             .collect::<Result<Vec<_>>>()?;
 
         // double check each array has the same length (aka the
@@ -348,7 +348,7 @@ pub(crate) fn slice_and_maybe_filter(
         sliced_arrays
             .iter()
             .map(|array| {
-                compute::filter(array, &filter_array).map_err(DataFusionError::ArrowError)
+                compute::filter(array, filter_array).map_err(DataFusionError::ArrowError)
             })
             .collect()
     } else {
diff --git a/datafusion/physical-expr/src/aggregate/sum.rs b/datafusion/physical-expr/src/aggregate/sum.rs
index 7b093d17d15f..e89eca2e65b8 100644
--- a/datafusion/physical-expr/src/aggregate/sum.rs
+++ b/datafusion/physical-expr/src/aggregate/sum.rs
@@ -601,11 +601,8 @@ where
 
         let sums = adjust_output_array(&self.sum_data_type, sums)?;
 
-        let counts = vec![0 as u64; sums.len()];
-        let counts = Arc::new(PrimitiveArray::<UInt64Type>::new(
-            counts.into(),
-            nulls.clone(),
-        ));
+        let counts = vec![0_u64; sums.len()];
+        let counts = Arc::new(PrimitiveArray::<UInt64Type>::new(counts.into(), nulls));
 
         // TODO: Sum expects sum/count array, but count is not needed
         Ok(vec![sums.clone() as ArrayRef, counts as ArrayRef])