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perf: optimize map_extract function lookup for common key types #21237

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773f88d
optimize map_extract
lyne7-sc Mar 29, 2026
7e3177d
add bench case
lyne7-sc Apr 7, 2026
7e6eb12
remove benchmark (moved to separate PR)
lyne7-sc Apr 7, 2026
e84e86c
Merge branch 'main' into perf/map_extract
lyne7-sc Apr 7, 2026
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132 changes: 122 additions & 10 deletions datafusion/functions-nested/src/map_extract.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -19,10 +19,14 @@

use crate::utils::{get_map_entry_field, make_scalar_function};
use arrow::array::{
Array, ArrayRef, Capacities, ListArray, MapArray, MutableArrayData, make_array,
Array, ArrayAccessor, ArrayRef, Capacities, ListArray, MapArray, MutableArrayData,
cast::AsArray, make_array,
};
use arrow::buffer::OffsetBuffer;
use arrow::datatypes::{DataType, Field};
use arrow::datatypes::{
DataType, Date32Type, Date64Type, Field, Int8Type, Int16Type, Int32Type, Int64Type,
UInt8Type, UInt16Type, UInt32Type, UInt64Type,
};
use datafusion_common::utils::take_function_args;
use datafusion_common::{Result, cast::as_map_array, exec_err};
use datafusion_expr::{
Expand Down Expand Up @@ -130,11 +134,41 @@ impl ScalarUDFImpl for MapExtract {
}
}

/// Fast path for key types that support direct typed value comparison.
///
/// This avoids the generic single-element slice comparison used by
/// `general_map_extract_inner`.
fn specialized_map_extract_inner<A>(
map_array: &MapArray,
keys: A,
query_keys: A,
) -> Result<ArrayRef>
where
A: ArrayAccessor,
A::Item: PartialEq,
{
map_extract_with_match(map_array, move |row_index, key_index| {
query_keys.is_valid(row_index)
&& keys.is_valid(key_index)
&& keys.value(key_index) == query_keys.value(row_index)
})
}

fn general_map_extract_inner(
map_array: &MapArray,
query_keys_array: &dyn Array,
) -> Result<ArrayRef> {
let keys = map_array.keys();
map_extract_with_match(map_array, |row_index, key_index| {
let query_key = query_keys_array.slice(row_index, 1);
query_keys_array.is_valid(row_index)
&& map_array.keys().slice(key_index, 1).as_ref() == query_key.as_ref()
})
}

fn map_extract_with_match(
map_array: &MapArray,
mut key_matches: impl FnMut(usize, usize) -> bool,
) -> Result<ArrayRef> {
let mut offsets = vec![0_i32];

let values = map_array.values();
Expand All @@ -147,16 +181,12 @@ fn general_map_extract_inner(
for (row_index, offset_window) in map_array.value_offsets().windows(2).enumerate() {
let start = offset_window[0] as usize;
let end = offset_window[1] as usize;
let len = end - start;

let query_key = query_keys_array.slice(row_index, 1);

let value_index =
(0..len).find(|&i| keys.slice(start + i, 1).as_ref() == query_key.as_ref());
(start..end).find(|&key_index| key_matches(row_index, key_index));

match value_index {
Some(index) => {
mutable.extend(0, start + index, start + index + 1);
mutable.extend(0, index, index + 1);
}
None => {
mutable.extend_nulls(1);
Expand Down Expand Up @@ -193,5 +223,87 @@ fn map_extract_inner(args: &[ArrayRef]) -> Result<ArrayRef> {
);
}

general_map_extract_inner(map_array, key_arg)
match key_type {
DataType::Int8 => specialized_map_extract_inner(
map_array,
map_array.keys().as_primitive::<Int8Type>(),
key_arg.as_primitive::<Int8Type>(),
),
DataType::Int16 => specialized_map_extract_inner(
map_array,
map_array.keys().as_primitive::<Int16Type>(),
key_arg.as_primitive::<Int16Type>(),
),
DataType::Int32 => specialized_map_extract_inner(
map_array,
map_array.keys().as_primitive::<Int32Type>(),
key_arg.as_primitive::<Int32Type>(),
),
DataType::Int64 => specialized_map_extract_inner(
map_array,
map_array.keys().as_primitive::<Int64Type>(),
key_arg.as_primitive::<Int64Type>(),
),
DataType::UInt8 => specialized_map_extract_inner(
map_array,
map_array.keys().as_primitive::<UInt8Type>(),
key_arg.as_primitive::<UInt8Type>(),
),
DataType::UInt16 => specialized_map_extract_inner(
map_array,
map_array.keys().as_primitive::<UInt16Type>(),
key_arg.as_primitive::<UInt16Type>(),
),
DataType::UInt32 => specialized_map_extract_inner(
map_array,
map_array.keys().as_primitive::<UInt32Type>(),
key_arg.as_primitive::<UInt32Type>(),
),
DataType::UInt64 => specialized_map_extract_inner(
map_array,
map_array.keys().as_primitive::<UInt64Type>(),
key_arg.as_primitive::<UInt64Type>(),
),
DataType::Date32 => specialized_map_extract_inner(
map_array,
map_array.keys().as_primitive::<Date32Type>(),
key_arg.as_primitive::<Date32Type>(),
),
DataType::Date64 => specialized_map_extract_inner(
map_array,
map_array.keys().as_primitive::<Date64Type>(),
key_arg.as_primitive::<Date64Type>(),
),
DataType::Utf8 => specialized_map_extract_inner(
map_array,
map_array.keys().as_string::<i32>(),
key_arg.as_string::<i32>(),
),
DataType::LargeUtf8 => specialized_map_extract_inner(
map_array,
map_array.keys().as_string::<i64>(),
key_arg.as_string::<i64>(),
),
DataType::Utf8View => specialized_map_extract_inner(
map_array,
map_array.keys().as_string_view(),
key_arg.as_string_view(),
),
DataType::Binary => specialized_map_extract_inner(
map_array,
map_array.keys().as_binary::<i32>(),
key_arg.as_binary::<i32>(),
),
DataType::LargeBinary => specialized_map_extract_inner(
map_array,
map_array.keys().as_binary::<i64>(),
key_arg.as_binary::<i64>(),
),
DataType::BinaryView => specialized_map_extract_inner(
map_array,
map_array.keys().as_binary_view(),
key_arg.as_binary_view(),
),
_ => general_map_extract_inner(map_array, key_arg),
}
}
16 changes: 16 additions & 0 deletions datafusion/sqllogictest/test_files/map.slt
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Original file line number Diff line number Diff line change
Expand Up @@ -642,6 +642,22 @@ select map_extract(MAP {1: 1, 2: 2, 3:3}, '1'), map_extract(MAP {1: 1, 2: 2, 3:3
----
[1] [1] [1] [NULL] [1]

# binary and binary view keys
query ????
select map_extract(MAP {arrow_cast('a', 'Binary'): 1, arrow_cast('b', 'Binary'): 2}, arrow_cast('b', 'Binary')),
map_extract(MAP {arrow_cast('a', 'LargeBinary'): 1, arrow_cast('b', 'LargeBinary'): 2}, arrow_cast('c', 'LargeBinary')),
map_extract(MAP {arrow_cast('a', 'BinaryView'): 1, arrow_cast('b', 'BinaryView'): 2}, arrow_cast('b', 'BinaryView')),
map_extract(MAP {arrow_cast('a', 'BinaryView'): 1, arrow_cast('b', 'BinaryView'): 2}, arrow_cast(NULL, 'BinaryView'));
----
[2] [NULL] [2] [NULL]

# nested datatype keys
query ??
select map_extract(MAP {[1, 2]: 10, [3, 4]: 20}, [3, 4]),
map_extract(MAP {[1, 2]: 10, [3, 4]: 20}, [5, 6]);
----
[20] [NULL]

# map_extract with columns
query ???
select map_extract(column1, 1), map_extract(column1, 5), map_extract(column1, 7) from map_array_table_1;
Expand Down
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