Avoid RowConverter for multi column grouping (10% faster clickbench queries)

benchmarks/queries/clickbench/queries.sql

@@ -40,4 +40,4 @@ SELECT "URL", COUNT(*) AS PageViews FROM hits WHERE "CounterID" = 62 AND "EventD
 SELECT "TraficSourceID", "SearchEngineID", "AdvEngineID", CASE WHEN ("SearchEngineID" = 0 AND "AdvEngineID" = 0) THEN "Referer" ELSE '' END AS Src, "URL" AS Dst, COUNT(*) AS PageViews FROM hits WHERE "CounterID" = 62 AND "EventDate"::INT::DATE >= '2013-07-01' AND "EventDate"::INT::DATE <= '2013-07-31' AND "IsRefresh" = 0 GROUP BY "TraficSourceID", "SearchEngineID", "AdvEngineID", Src, Dst ORDER BY PageViews DESC LIMIT 10 OFFSET 1000;
 SELECT "URLHash", "EventDate"::INT::DATE, COUNT(*) AS PageViews FROM hits WHERE "CounterID" = 62 AND "EventDate"::INT::DATE >= '2013-07-01' AND "EventDate"::INT::DATE <= '2013-07-31' AND "IsRefresh" = 0 AND "TraficSourceID" IN (-1, 6) AND "RefererHash" = 3594120000172545465 GROUP BY "URLHash", "EventDate"::INT::DATE ORDER BY PageViews DESC LIMIT 10 OFFSET 100;
 SELECT "WindowClientWidth", "WindowClientHeight", COUNT(*) AS PageViews FROM hits WHERE "CounterID" = 62 AND "EventDate"::INT::DATE >= '2013-07-01' AND "EventDate"::INT::DATE <= '2013-07-31' AND "IsRefresh" = 0 AND "DontCountHits" = 0 AND "URLHash" = 2868770270353813622 GROUP BY "WindowClientWidth", "WindowClientHeight" ORDER BY PageViews DESC LIMIT 10 OFFSET 10000;
-SELECT DATE_TRUNC('minute', to_timestamp_seconds("EventTime")) AS M, COUNT(*) AS PageViews FROM hits WHERE "CounterID" = 62 AND "EventDate"::INT::DATE >= '2013-07-14' AND "EventDate"::INT::DATE <= '2013-07-15' AND "IsRefresh" = 0 AND "DontCountHits" = 0 GROUP BY DATE_TRUNC('minute', to_timestamp_seconds("EventTime")) ORDER BY DATE_TRUNC('minute', M) LIMIT 10 OFFSET 1000;
+SELECT DATE_TRUNC('minute', to_timestamp_seconds("EventTime")) AS M, COUNT(*) AS PageViews FROM hits WHERE "CounterID" = 62 AND "EventDate"::INT::DATE >= '2013-07-14' AND "EventDate"::INT::DATE <= '2013-07-15' AND "IsRefresh" = 0 AND "DontCountHits" = 0 GROUP BY DATE_TRUNC('minute', to_timestamp_seconds("EventTime")) ORDER BY DATE_TRUNC('minute', M) LIMIT 10 OFFSET 1000;

datafusion/physical-expr-common/src/binary_map.rs

@@ -235,9 +235,9 @@ where
 }
 
 /// The size, in number of entries, of the initial hash table
-const INITIAL_MAP_CAPACITY: usize = 128;
+pub(super) const INITIAL_MAP_CAPACITY: usize = 128;
 /// The initial size, in bytes, of the string data
-const INITIAL_BUFFER_CAPACITY: usize = 8 * 1024;
+pub const INITIAL_BUFFER_CAPACITY: usize = 8 * 1024;
 impl<O: OffsetSizeTrait, V> ArrowBytesMap<O, V>
 where
     V: Debug + PartialEq + Eq + Clone + Copy + Default,

datafusion/physical-plan/src/aggregates/group_values/column_wise.rs

@@ -0,0 +1,315 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+use crate::aggregates::group_values::group_value_row::{
+    ArrayRowEq, ByteGroupValueBuilder, PrimitiveGroupValueBuilder,
+};
+use crate::aggregates::group_values::GroupValues;
+use ahash::RandomState;
+use arrow::compute::cast;
+use arrow::datatypes::{
+    Date32Type, Date64Type, Float32Type, Float64Type, Int16Type, Int32Type, Int64Type,
+    Int8Type, UInt16Type, UInt32Type, UInt64Type, UInt8Type,
+};
+use arrow::record_batch::RecordBatch;
+use arrow_array::{Array, ArrayRef};
+use arrow_schema::{DataType, SchemaRef};
+use datafusion_common::hash_utils::create_hashes;
+use datafusion_common::{DataFusionError, Result};
+use datafusion_execution::memory_pool::proxy::{RawTableAllocExt, VecAllocExt};
+use datafusion_expr::EmitTo;
+use datafusion_physical_expr::binary_map::OutputType;
+
+use hashbrown::raw::RawTable;
+
+/// Compare GroupValue Rows column by column
+pub struct GroupValuesColumn {
+    /// The output schema
+    schema: SchemaRef,
+
+    /// Logically maps group values to a group_index in
+    /// [`Self::group_values`] and in each accumulator
+    ///
+    /// Uses the raw API of hashbrown to avoid actually storing the
+    /// keys (group values) in the table
+    ///
+    /// keys: u64 hashes of the GroupValue
+    /// values: (hash, group_index)
+    map: RawTable<(u64, usize)>,
+
+    /// The size of `map` in bytes
+    map_size: usize,
+
+    /// The actual group by values, stored column-wise. Compare from
+    /// the left to right, each column is stored as `ArrayRowEq`.
+    /// This is shown faster than the row format
+    group_values: Vec<Box<dyn ArrayRowEq>>,
+
+    /// reused buffer to store hashes
+    hashes_buffer: Vec<u64>,
+
+    /// Random state for creating hashes
+    random_state: RandomState,
+}
+
+impl GroupValuesColumn {
+    pub fn try_new(schema: SchemaRef) -> Result<Self> {
+        let map = RawTable::with_capacity(0);
+        Ok(Self {
+            schema,
+            map,
+            map_size: 0,
+            group_values: vec![],
+            hashes_buffer: Default::default(),
+            random_state: Default::default(),
+        })
+    }
+}
+
+impl GroupValues for GroupValuesColumn {
+    fn intern(&mut self, cols: &[ArrayRef], groups: &mut Vec<usize>) -> Result<()> {
+        let n_rows = cols[0].len();
+
+        if self.group_values.is_empty() {
+            let len = cols.len();
+            let mut v = Vec::with_capacity(len);
+
+            for f in self.schema.fields().iter() {
+                let nullable = f.is_nullable();
+                match f.data_type() {
+                    &DataType::Int8 => {
+                        let b = PrimitiveGroupValueBuilder::<Int8Type>::new(nullable);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::Int16 => {
+                        let b = PrimitiveGroupValueBuilder::<Int16Type>::new(nullable);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::Int32 => {
+                        let b = PrimitiveGroupValueBuilder::<Int32Type>::new(nullable);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::Int64 => {
+                        let b = PrimitiveGroupValueBuilder::<Int64Type>::new(nullable);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::UInt8 => {
+                        let b = PrimitiveGroupValueBuilder::<UInt8Type>::new(nullable);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::UInt16 => {
+                        let b = PrimitiveGroupValueBuilder::<UInt16Type>::new(nullable);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::UInt32 => {
+                        let b = PrimitiveGroupValueBuilder::<UInt32Type>::new(nullable);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::UInt64 => {
+                        let b = PrimitiveGroupValueBuilder::<UInt64Type>::new(nullable);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::Float32 => {
+                        let b = PrimitiveGroupValueBuilder::<Float32Type>::new(nullable);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::Float64 => {
+                        let b = PrimitiveGroupValueBuilder::<Float64Type>::new(nullable);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::Date32 => {
+                        let b = PrimitiveGroupValueBuilder::<Date32Type>::new(nullable);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::Date64 => {
+                        let b = PrimitiveGroupValueBuilder::<Date64Type>::new(nullable);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::Utf8 => {
+                        let b = ByteGroupValueBuilder::<i32>::new(OutputType::Utf8);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::LargeUtf8 => {
+                        let b = ByteGroupValueBuilder::<i64>::new(OutputType::Utf8);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::Binary => {
+                        let b = ByteGroupValueBuilder::<i32>::new(OutputType::Binary);
+                        v.push(Box::new(b) as _)
+                    }
+                    &DataType::LargeBinary => {
+                        let b = ByteGroupValueBuilder::<i64>::new(OutputType::Binary);
+                        v.push(Box::new(b) as _)
+                    }
+                    dt => todo!("{dt} not impl"),
+                }
+            }
+            self.group_values = v;
+        }
+
+        // tracks to which group each of the input rows belongs
+        groups.clear();
+
+        // 1.1 Calculate the group keys for the group values
+        let batch_hashes = &mut self.hashes_buffer;
+        batch_hashes.clear();
+        batch_hashes.resize(n_rows, 0);
+        create_hashes(cols, &self.random_state, batch_hashes)?;
+
+        for (row, &target_hash) in batch_hashes.iter().enumerate() {
+            let entry = self.map.get_mut(target_hash, |(exist_hash, group_idx)| {
+                // Somewhat surprisingly, this closure can be called even if the
+                // hash doesn't match, so check the hash first with an integer
+                // comparison first avoid the more expensive comparison with
+                // group value. https://github.com/apache/datafusion/pull/11718
+                if target_hash != *exist_hash {
+                    return false;
+                }
+
+                fn check_row_equal(
+                    array_row: &dyn ArrayRowEq,
+                    lhs_row: usize,
+                    array: &ArrayRef,
+                    rhs_row: usize,
+                ) -> bool {
+                    array_row.equal_to(lhs_row, array, rhs_row)
+                }
+
+                for (i, group_val) in self.group_values.iter().enumerate() {
+                    if !check_row_equal(group_val.as_ref(), *group_idx, &cols[i], row) {
+                        return false;
+                    }
+                }
+
+                true
+            });
+
+            let group_idx = match entry {
+                // Existing group_index for this group value
+                Some((_hash, group_idx)) => *group_idx,
+                //  1.2 Need to create new entry for the group
+                None => {
+                    // Add new entry to aggr_state and save newly created index
+                    // let group_idx = group_values.num_rows();
+                    // group_values.push(group_rows.row(row));
+
+                    let mut checklen = 0;
+                    let group_idx = self.group_values[0].len();
+                    for (i, group_value) in self.group_values.iter_mut().enumerate() {
+                        group_value.append_val(&cols[i], row);
+                        let len = group_value.len();
+                        if i == 0 {
+                            checklen = len;
+                        } else {
+                            debug_assert_eq!(checklen, len);
+                        }
+                    }
+
+                    // for hasher function, use precomputed hash value
+                    self.map.insert_accounted(
+                        (target_hash, group_idx),
+                        |(hash, _group_index)| *hash,
+                        &mut self.map_size,
+                    );
+                    group_idx
+                }
+            };
+            groups.push(group_idx);
+        }
+
+        Ok(())
+    }
+
+    fn size(&self) -> usize {
+        let group_values_size = self.group_values.len();
+        group_values_size + self.map_size + self.hashes_buffer.allocated_size()
+    }
+
+    fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
+    fn len(&self) -> usize {
+        if self.group_values.is_empty() {
+            return 0;
+        }
+
+        self.group_values[0].len()
+    }
+
+    fn emit(&mut self, emit_to: EmitTo) -> Result<Vec<ArrayRef>> {
+        let mut output = match emit_to {
+            EmitTo::All => {
+                let group_values = std::mem::take(&mut self.group_values);
+                debug_assert!(self.group_values.is_empty());
+
+                group_values
+                    .into_iter()
+                    .map(|v| v.build())
+                    .collect::<Vec<_>>()
+            }
+            EmitTo::First(n) => {
+                let output = self
+                    .group_values
+                    .iter_mut()
+                    .map(|v| v.take_n(n))
+                    .collect::<Vec<_>>();
+
+                // SAFETY: self.map outlives iterator and is not modified concurrently
+                unsafe {
+                    for bucket in self.map.iter() {
+                        // Decrement group index by n
+                        match bucket.as_ref().1.checked_sub(n) {
+                            // Group index was >= n, shift value down
+                            Some(sub) => bucket.as_mut().1 = sub,
+                            // Group index was < n, so remove from table
+                            None => self.map.erase(bucket),
+                        }
+                    }
+                }
+
+                output
+            }
+        };
+
+        // TODO: Materialize dictionaries in group keys (#7647)
+        for (field, array) in self.schema.fields.iter().zip(&mut output) {
+            let expected = field.data_type();
+            if let DataType::Dictionary(_, v) = expected {
+                let actual = array.data_type();
+                if v.as_ref() != actual {
+                    return Err(DataFusionError::Internal(format!(
+                        "Converted group rows expected dictionary of {v} got {actual}"
+                    )));
+                }
+                *array = cast(array.as_ref(), expected)?;
+            }
+        }
+
+        Ok(output)
+    }
+
+    fn clear_shrink(&mut self, batch: &RecordBatch) {
+        let count = batch.num_rows();
+        self.group_values.clear();
+        self.map.clear();
+        self.map.shrink_to(count, |_| 0); // hasher does not matter since the map is cleared
+        self.map_size = self.map.capacity() * std::mem::size_of::<(u64, usize)>();
+        self.hashes_buffer.clear();
+        self.hashes_buffer.shrink_to(count);
+    }
+}