Function flat_batch

datafusion/core/benches/parquet_struct_projection.rs:415–436

(batch_id: usize)

}

fn flat_batch(batch_id: usize) -> RecordBatch {
    let schema = flat_schema();
    let len = WRITE_RECORD_BATCH_SIZE;

    let base_id = (batch_id * len) as i32;
    let id_values: Vec<i32> = (0..len).map(|i| base_id + i as i32).collect();
    let id_array = Arc::new(Int32Array::from(id_values.clone()));
    let small_int_array = Arc::new(Int32Array::from(id_values));

    let large_string: String = "x".repeat(LARGE_STRING_LEN);
    let mut string_builder = StringBuilder::new();
    for _ in 0..len {
        string_builder.append_value(&large_string);
    }
    let large_string_array = Arc::new(string_builder.finish());

    RecordBatch::try_new(
        schema,
        vec![id_array, large_string_array as ArrayRef, small_int_array],
    )
    .unwrap()
}

/// Compare selecting a small field from a flat (top-level) schema vs from
/// inside a struct. Both files contain the same logical data — the only