Small draft for aggregation. Should't be merged

Author: waralexrom

datafusion/src/physical_plan/hash_aggregate.rs

@@ -79,7 +79,7 @@ use super::{
 use crate::cube_ext;
 
 use crate::cube_ext::ordfloat::{OrdF32, OrdF64};
-use crate::physical_plan::sorted_aggregate::SortedAggState;
+use crate::physical_plan::sorted_aggregate::{agg_key_equals, SortedAggState};
 use compute::cast;
 use smallvec::smallvec;
 use smallvec::SmallVec;
@@ -440,13 +440,20 @@ pub(crate) fn group_aggregate_batch(
     // Keys received in this batch
     let mut batch_keys = BinaryBuilder::new(0);
 
-    for row in 0..batch.num_rows() {
+    let mut row: usize = 0;
+
+    while row < batch.num_rows() {
         if skip_row(&batch, row) {
             continue;
         }
         // 1.1
         create_key(&group_values, row, &mut key)
             .map_err(DataFusionError::into_arrow_external_error)?;
+        let start = row;
+        row += 1;
+        while row < batch.num_rows() && agg_key_equals(&key, &group_values, row)? {
+            row += 1;
+        }
 
         accumulators
             .raw_entry_mut()
@@ -456,7 +463,7 @@ pub(crate) fn group_aggregate_batch(
                 if v.is_empty() {
                     batch_keys.append_value(&key).expect("must not fail");
                 };
-                v.push(row as u32)
+                v.extend((start as u32..row as u32).into_iter())
             })
             // 1.2
             .or_insert_with(|| {
@@ -469,7 +476,11 @@ pub(crate) fn group_aggregate_batch(
                 std::mem::swap(&mut taken_values, &mut group_by_values);
                 (
                     key.clone(),
-                    (taken_values, accumulator_set, smallvec![row as u32]),
+                    (
+                        taken_values,
+                        accumulator_set,
+                        smallvec![(start as u32..row as u32).into_iter()],
+                    ),
                 )
             });
     }

datafusion/src/physical_plan/sorted_aggregate.rs

@@ -192,7 +192,7 @@ impl SortedAggState {
     }
 }
 
-fn agg_key_equals(
+pub fn agg_key_equals(
     key: &[GroupByScalar],
     key_columns: &[ArrayRef],
     row: usize,