From a643da81f3009c273c1e4dcc77cb1ef33ddb47bd Mon Sep 17 00:00:00 2001
From: Pepijn Van Eeckhoudt <pepijn@vaneeckhoudt.net>
Date: Sat, 11 Oct 2025 11:56:46 +0200
Subject: [PATCH] Add RecordBatch::project microbenchmark

---
 arrow-array/Cargo.toml              |  4 ++
 arrow-array/benches/record_batch.rs | 92 +++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)
 create mode 100644 arrow-array/benches/record_batch.rs

diff --git a/arrow-array/Cargo.toml b/arrow-array/Cargo.toml
index e2cfd14e098b..3308fe7f2dea 100644
--- a/arrow-array/Cargo.toml
+++ b/arrow-array/Cargo.toml
@@ -80,3 +80,7 @@ harness = false
 [[bench]]
 name = "union_array"
 harness = false
+
+[[bench]]
+name = "record_batch"
+harness = false
\ No newline at end of file
diff --git a/arrow-array/benches/record_batch.rs b/arrow-array/benches/record_batch.rs
new file mode 100644
index 000000000000..ec53ae413b3d
--- /dev/null
+++ b/arrow-array/benches/record_batch.rs
@@ -0,0 +1,92 @@
+// 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 arrow_array::{ArrayRef, Int64Array, RecordBatch, RecordBatchOptions};
+use arrow_schema::{DataType, Field, Schema, SchemaRef};
+use criterion::*;
+use num_integer::Integer;
+use std::sync::Arc;
+
+fn make_record_batch(column_count: usize, row_count: usize) -> RecordBatch {
+    let fields = (0..column_count)
+        .map(|i| Field::new(format!("col_{}", i), DataType::Int64, i.is_even()))
+        .collect::<Vec<_>>();
+
+    let columns = fields
+        .iter()
+        .map(|_| {
+            let array_ref: ArrayRef = Arc::new(Int64Array::from_value(0, row_count));
+            array_ref
+        })
+        .collect::<Vec<_>>();
+
+    let schema = Schema::new(fields);
+
+    let mut options = RecordBatchOptions::new();
+    options.row_count = Some(row_count);
+
+    RecordBatch::try_new_with_options(SchemaRef::new(schema), columns, &options).unwrap()
+}
+
+fn project_benchmark(
+    c: &mut Criterion,
+    column_count: usize,
+    row_count: usize,
+    projection_size: usize,
+) {
+    let input = make_input(column_count, row_count, projection_size);
+
+    c.bench_with_input(
+        BenchmarkId::new(
+            "project",
+            format!(
+                "{:?}x{:?} -> {:?}x{:?}",
+                input.0.num_columns(),
+                input.0.num_rows(),
+                input.1.len(),
+                input.0.num_rows()
+            ),
+        ),
+        &input,
+        |b, (rb, projection)| {
+            b.iter(|| black_box(rb.project(projection).unwrap()));
+        },
+    );
+}
+
+fn make_input(
+    column_count: usize,
+    row_count: usize,
+    projection_size: usize,
+) -> (RecordBatch, Vec<usize>) {
+    let rb = make_record_batch(column_count, row_count);
+    let projection = (0..projection_size).collect::<Vec<_>>();
+    (rb, projection)
+}
+
+fn criterion_benchmark(c: &mut Criterion) {
+    [10, 100, 1000].iter().for_each(|&column_count| {
+        [1, column_count / 2, column_count - 1]
+            .iter()
+            .for_each(|&projection_size| {
+                project_benchmark(c, column_count, 8192, projection_size);
+            })
+    });
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);