diff --git a/native/Cargo.lock b/native/Cargo.lock
index a7f8359d87..67d041a399 100644
--- a/native/Cargo.lock
+++ b/native/Cargo.lock
@@ -942,10 +942,12 @@ dependencies = [
  "datafusion-common",
  "datafusion-expr",
  "datafusion-physical-expr",
+ "futures",
  "num",
  "rand",
  "regex",
  "thiserror",
+ "tokio",
  "twox-hash 2.0.1",
 ]
 
diff --git a/native/Cargo.toml b/native/Cargo.toml
index 85c46a6d02..4ac85479f2 100644
--- a/native/Cargo.toml
+++ b/native/Cargo.toml
@@ -51,6 +51,7 @@ datafusion-comet-spark-expr = { path = "spark-expr", version = "0.5.0" }
 datafusion-comet-proto = { path = "proto", version = "0.5.0" }
 chrono = { version = "0.4", default-features = false, features = ["clock"] }
 chrono-tz = { version = "0.8" }
+futures = "0.3.28"
 num = "0.4"
 rand = "0.8"
 regex = "1.9.6"
diff --git a/native/core/Cargo.toml b/native/core/Cargo.toml
index daa0837c82..4b9753ec51 100644
--- a/native/core/Cargo.toml
+++ b/native/core/Cargo.toml
@@ -42,7 +42,7 @@ arrow-data = { workspace = true }
 arrow-schema = { workspace = true }
 parquet = { workspace = true, default-features = false, features = ["experimental"] }
 half = { version = "2.4.1", default-features = false }
-futures = "0.3.28"
+futures = { workspace = true }
 mimalloc = { version = "*", default-features = false, optional = true }
 tokio = { version = "1", features = ["rt-multi-thread"] }
 async-trait = "0.1"
@@ -88,7 +88,6 @@ hex = "0.4.3"
 
 [features]
 default = []
-nightly = []
 
 [lib]
 name = "comet"
@@ -123,10 +122,6 @@ harness = false
 name = "filter"
 harness = false
 
-[[bench]]
-name = "aggregate"
-harness = false
-
 [[bench]]
 name = "bloom_filter_agg"
 harness = false
diff --git a/native/core/src/common/bit.rs b/native/core/src/common/bit.rs
index 871786bb15..72d7729d93 100644
--- a/native/core/src/common/bit.rs
+++ b/native/core/src/common/bit.rs
@@ -17,14 +17,12 @@
 
 use std::{cmp::min, mem::size_of};
 
-use arrow::buffer::Buffer;
-
 use crate::{
     errors::CometResult as Result,
-    likely,
     parquet::{data_type::AsBytes, util::bit_packing::unpack32},
-    unlikely,
 };
+use arrow::buffer::Buffer;
+use datafusion_comet_spark_expr::utils::{likely, unlikely};
 
 #[inline]
 pub fn from_ne_slice<T: FromBytes>(bs: &[u8]) -> T {
diff --git a/native/core/src/execution/datafusion/expressions/checkoverflow.rs b/native/core/src/execution/datafusion/expressions/checkoverflow.rs
index ed03ab667f..e922171bd2 100644
--- a/native/core/src/execution/datafusion/expressions/checkoverflow.rs
+++ b/native/core/src/execution/datafusion/expressions/checkoverflow.rs
@@ -27,8 +27,7 @@ use arrow::{
     datatypes::{Decimal128Type, DecimalType},
     record_batch::RecordBatch,
 };
-use arrow_data::decimal::{MAX_DECIMAL_FOR_EACH_PRECISION, MIN_DECIMAL_FOR_EACH_PRECISION};
-use arrow_schema::{DataType, Schema, DECIMAL128_MAX_PRECISION};
+use arrow_schema::{DataType, Schema};
 use datafusion::logical_expr::ColumnarValue;
 use datafusion::physical_expr_common::physical_expr::down_cast_any_ref;
 use datafusion_common::{DataFusionError, ScalarValue};
@@ -172,15 +171,3 @@ impl PhysicalExpr for CheckOverflow {
         self.hash(&mut s);
     }
 }
-
-/// Adapted from arrow-rs `validate_decimal_precision` but returns bool
-/// instead of Err to avoid the cost of formatting the error strings and is
-/// optimized to remove a memcpy that exists in the original function
-/// we can remove this code once we upgrade to a version of arrow-rs that
-/// includes https://github.com/apache/arrow-rs/pull/6419
-#[inline]
-pub fn is_valid_decimal_precision(value: i128, precision: u8) -> bool {
-    precision <= DECIMAL128_MAX_PRECISION
-        && value >= MIN_DECIMAL_FOR_EACH_PRECISION[precision as usize - 1]
-        && value <= MAX_DECIMAL_FOR_EACH_PRECISION[precision as usize - 1]
-}
diff --git a/native/core/src/execution/datafusion/expressions/mod.rs b/native/core/src/execution/datafusion/expressions/mod.rs
index 48b80384b0..2bb14df36e 100644
--- a/native/core/src/execution/datafusion/expressions/mod.rs
+++ b/native/core/src/execution/datafusion/expressions/mod.rs
@@ -17,26 +17,15 @@
 
 //! Native DataFusion expressions
 
-pub mod bitwise_not;
 pub mod checkoverflow;
-mod normalize_nan;
-pub use normalize_nan::NormalizeNaNAndZero;
 
 use crate::errors::CometError;
-pub mod avg;
-pub mod avg_decimal;
 pub mod bloom_filter_agg;
 pub mod bloom_filter_might_contain;
-pub mod comet_scalar_funcs;
-pub mod correlation;
-pub mod covariance;
 pub mod negative;
-pub mod stddev;
 pub mod strings;
 pub mod subquery;
-pub mod sum_decimal;
 pub mod unbound;
-pub mod variance;
 
 pub use datafusion_comet_spark_expr::{EvalMode, SparkError};
 
diff --git a/native/core/src/execution/datafusion/planner.rs b/native/core/src/execution/datafusion/planner.rs
index 33c4924cbd..a83dba5d63 100644
--- a/native/core/src/execution/datafusion/planner.rs
+++ b/native/core/src/execution/datafusion/planner.rs
@@ -18,29 +18,19 @@
 //! Converts Spark physical plan to DataFusion physical plan
 
 use super::expressions::EvalMode;
-use crate::execution::datafusion::expressions::comet_scalar_funcs::create_comet_physical_fun;
 use crate::execution::operators::{CopyMode, FilterExec};
 use crate::{
     errors::ExpressionError,
     execution::{
         datafusion::{
             expressions::{
-                avg::Avg,
-                avg_decimal::AvgDecimal,
-                bitwise_not::BitwiseNotExpr,
                 bloom_filter_agg::BloomFilterAgg,
                 bloom_filter_might_contain::BloomFilterMightContain,
                 checkoverflow::CheckOverflow,
-                correlation::Correlation,
-                covariance::Covariance,
                 negative,
-                stddev::Stddev,
                 strings::{Contains, EndsWith, Like, StartsWith, StringSpaceExpr, SubstringExpr},
                 subquery::Subquery,
-                sum_decimal::SumDecimal,
                 unbound::UnboundColumn,
-                variance::Variance,
-                NormalizeNaNAndZero,
             },
             operators::expand::CometExpandExec,
             shuffle_writer::ShuffleWriterExec,
@@ -82,6 +72,7 @@ use datafusion::{
     },
     prelude::SessionContext,
 };
+use datafusion_comet_spark_expr::create_comet_physical_fun;
 use datafusion_functions_nested::concat::ArrayAppend;
 use datafusion_physical_expr::aggregate::{AggregateExprBuilder, AggregateFunctionExpr};
 
@@ -99,9 +90,10 @@ use datafusion_comet_proto::{
     spark_partitioning::{partitioning::PartitioningStruct, Partitioning as SparkPartitioning},
 };
 use datafusion_comet_spark_expr::{
-    ArrayInsert, Cast, CreateNamedStruct, DateTruncExpr, GetArrayStructFields, GetStructField,
-    HourExpr, IfExpr, ListExtract, MinuteExpr, RLike, SecondExpr, SparkCastOptions,
-    TimestampTruncExpr, ToJson,
+    ArrayInsert, Avg, AvgDecimal, BitwiseNotExpr, Cast, Correlation, Covariance, CreateNamedStruct,
+    DateTruncExpr, GetArrayStructFields, GetStructField, HourExpr, IfExpr, ListExtract, MinuteExpr,
+    NormalizeNaNAndZero, RLike, SecondExpr, SparkCastOptions, Stddev, SumDecimal,
+    TimestampTruncExpr, ToJson, Variance,
 };
 use datafusion_common::scalar::ScalarStructBuilder;
 use datafusion_common::{
diff --git a/native/core/src/lib.rs b/native/core/src/lib.rs
index c6a7a4143d..68c8ae7299 100644
--- a/native/core/src/lib.rs
+++ b/native/core/src/lib.rs
@@ -104,30 +104,3 @@ fn default_logger_config() -> CometResult<Config> {
         .build(root)
         .map_err(|err| CometError::Config(err.to_string()))
 }
-
-// These are borrowed from hashbrown crate:
-//   https://github.com/rust-lang/hashbrown/blob/master/src/raw/mod.rs
-
-// On stable we can use #[cold] to get a equivalent effect: this attributes
-// suggests that the function is unlikely to be called
-#[cfg(not(feature = "nightly"))]
-#[inline]
-#[cold]
-fn cold() {}
-
-#[cfg(not(feature = "nightly"))]
-#[inline]
-fn likely(b: bool) -> bool {
-    if !b {
-        cold();
-    }
-    b
-}
-#[cfg(not(feature = "nightly"))]
-#[inline]
-fn unlikely(b: bool) -> bool {
-    if b {
-        cold();
-    }
-    b
-}
diff --git a/native/core/src/parquet/read/levels.rs b/native/core/src/parquet/read/levels.rs
index 3d74b277cc..9077c0e485 100644
--- a/native/core/src/parquet/read/levels.rs
+++ b/native/core/src/parquet/read/levels.rs
@@ -17,15 +17,14 @@
 
 use std::mem;
 
-use arrow::buffer::Buffer;
-use parquet::schema::types::ColumnDescPtr;
-
 use super::values::Decoder;
 use crate::{
     common::bit::{self, read_u32, BitReader},
     parquet::ParquetMutableVector,
-    unlikely,
 };
+use arrow::buffer::Buffer;
+use datafusion_comet_spark_expr::utils::unlikely;
+use parquet::schema::types::ColumnDescPtr;
 
 const INITIAL_BUF_LEN: usize = 16;
 
diff --git a/native/core/src/parquet/read/values.rs b/native/core/src/parquet/read/values.rs
index b439e29e6a..71cd035d2e 100644
--- a/native/core/src/parquet/read/values.rs
+++ b/native/core/src/parquet/read/values.rs
@@ -28,9 +28,9 @@ use crate::write_val_or_null;
 use crate::{
     common::bit::{self, BitReader},
     parquet::{data_type::*, ParquetMutableVector},
-    unlikely,
 };
 use arrow::datatypes::DataType as ArrowDataType;
+use datafusion_comet_spark_expr::utils::unlikely;
 
 pub fn get_decoder<T: DataType>(
     value_data: Buffer,
diff --git a/native/spark-expr/Cargo.toml b/native/spark-expr/Cargo.toml
index 532bf74375..65517431d2 100644
--- a/native/spark-expr/Cargo.toml
+++ b/native/spark-expr/Cargo.toml
@@ -29,6 +29,7 @@ edition = { workspace = true }
 [dependencies]
 arrow = { workspace = true }
 arrow-array = { workspace = true }
+arrow-data = { workspace = true }
 arrow-schema = { workspace = true }
 chrono = { workspace = true }
 datafusion = { workspace = true }
@@ -39,12 +40,14 @@ chrono-tz = { workspace = true }
 num = { workspace = true }
 regex = { workspace = true }
 thiserror = { workspace = true }
+futures = { workspace = true }
 twox-hash = "2.0.0"
 
 [dev-dependencies]
 arrow-data = {workspace = true}
 criterion = "0.5.1"
 rand = { workspace = true}
+tokio = { version = "1", features = ["rt-multi-thread"] }
 
 
 [lib]
@@ -66,3 +69,8 @@ harness = false
 [[bench]]
 name = "decimal_div"
 harness = false
+
+[[bench]]
+name = "aggregate"
+harness = false
+
diff --git a/native/core/benches/aggregate.rs b/native/spark-expr/benches/aggregate.rs
similarity index 97%
rename from native/core/benches/aggregate.rs
rename to native/spark-expr/benches/aggregate.rs
index c6209406fd..43194fdda2 100644
--- a/native/core/benches/aggregate.rs
+++ b/native/spark-expr/benches/aggregate.rs
@@ -19,16 +19,16 @@ use arrow::datatypes::{DataType, Field, Schema};
 use arrow_array::builder::{Decimal128Builder, StringBuilder};
 use arrow_array::{ArrayRef, RecordBatch};
 use arrow_schema::SchemaRef;
-use comet::execution::datafusion::expressions::avg_decimal::AvgDecimal;
-use comet::execution::datafusion::expressions::sum_decimal::SumDecimal;
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
+use datafusion::execution::TaskContext;
 use datafusion::functions_aggregate::average::avg_udaf;
 use datafusion::functions_aggregate::sum::sum_udaf;
 use datafusion::physical_expr::PhysicalExpr;
 use datafusion::physical_plan::aggregates::{AggregateExec, AggregateMode, PhysicalGroupBy};
 use datafusion::physical_plan::memory::MemoryExec;
 use datafusion::physical_plan::ExecutionPlan;
-use datafusion_execution::TaskContext;
+use datafusion_comet_spark_expr::AvgDecimal;
+use datafusion_comet_spark_expr::SumDecimal;
 use datafusion_expr::AggregateUDF;
 use datafusion_physical_expr::aggregate::AggregateExprBuilder;
 use datafusion_physical_expr::expressions::Column;
diff --git a/native/core/src/execution/datafusion/expressions/avg.rs b/native/spark-expr/src/avg.rs
similarity index 100%
rename from native/core/src/execution/datafusion/expressions/avg.rs
rename to native/spark-expr/src/avg.rs
diff --git a/native/core/src/execution/datafusion/expressions/avg_decimal.rs b/native/spark-expr/src/avg_decimal.rs
similarity index 99%
rename from native/core/src/execution/datafusion/expressions/avg_decimal.rs
rename to native/spark-expr/src/avg_decimal.rs
index a265fdc29e..163e1560b6 100644
--- a/native/core/src/execution/datafusion/expressions/avg_decimal.rs
+++ b/native/spark-expr/src/avg_decimal.rs
@@ -28,7 +28,7 @@ use datafusion_common::{not_impl_err, Result, ScalarValue};
 use datafusion_physical_expr::{expressions::format_state_name, PhysicalExpr};
 use std::{any::Any, sync::Arc};
 
-use crate::execution::datafusion::expressions::checkoverflow::is_valid_decimal_precision;
+use crate::utils::is_valid_decimal_precision;
 use arrow_array::ArrowNativeTypeOp;
 use arrow_data::decimal::{MAX_DECIMAL_FOR_EACH_PRECISION, MIN_DECIMAL_FOR_EACH_PRECISION};
 use datafusion::logical_expr::Volatility::Immutable;
diff --git a/native/core/src/execution/datafusion/expressions/bitwise_not.rs b/native/spark-expr/src/bitwise_not.rs
similarity index 88%
rename from native/core/src/execution/datafusion/expressions/bitwise_not.rs
rename to native/spark-expr/src/bitwise_not.rs
index a2b9ebe5b5..36234935e1 100644
--- a/native/core/src/execution/datafusion/expressions/bitwise_not.rs
+++ b/native/spark-expr/src/bitwise_not.rs
@@ -28,7 +28,7 @@ use arrow::{
 };
 use datafusion::physical_expr_common::physical_expr::down_cast_any_ref;
 use datafusion::{error::DataFusionError, logical_expr::ColumnarValue};
-use datafusion_common::{Result, ScalarValue};
+use datafusion_common::Result;
 use datafusion_physical_expr::PhysicalExpr;
 
 macro_rules! compute_op {
@@ -135,22 +135,6 @@ pub fn bitwise_not(arg: Arc<dyn PhysicalExpr>) -> Result<Arc<dyn PhysicalExpr>>
     Ok(Arc::new(BitwiseNotExpr::new(arg)))
 }
 
-fn scalar_bitwise_not(scalar: ScalarValue) -> Result<ScalarValue> {
-    match scalar {
-        ScalarValue::Int8(None)
-        | ScalarValue::Int16(None)
-        | ScalarValue::Int32(None)
-        | ScalarValue::Int64(None) => Ok(scalar),
-        ScalarValue::Int8(Some(v)) => Ok(ScalarValue::Int8(Some(!v))),
-        ScalarValue::Int16(Some(v)) => Ok(ScalarValue::Int16(Some(!v))),
-        ScalarValue::Int32(Some(v)) => Ok(ScalarValue::Int32(Some(!v))),
-        ScalarValue::Int64(Some(v)) => Ok(ScalarValue::Int64(Some(!v))),
-        value => Err(DataFusionError::Internal(format!(
-            "Can not run ! on scalar value {value:?}"
-        ))),
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use arrow::datatypes::*;
diff --git a/native/core/src/execution/datafusion/expressions/comet_scalar_funcs.rs b/native/spark-expr/src/comet_scalar_funcs.rs
similarity index 98%
rename from native/core/src/execution/datafusion/expressions/comet_scalar_funcs.rs
rename to native/spark-expr/src/comet_scalar_funcs.rs
index 06717aabeb..71ff0e9dcc 100644
--- a/native/core/src/execution/datafusion/expressions/comet_scalar_funcs.rs
+++ b/native/spark-expr/src/comet_scalar_funcs.rs
@@ -15,15 +15,15 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use arrow_schema::DataType;
-use datafusion_comet_spark_expr::scalar_funcs::hash_expressions::{
+use crate::scalar_funcs::hash_expressions::{
     spark_sha224, spark_sha256, spark_sha384, spark_sha512,
 };
-use datafusion_comet_spark_expr::scalar_funcs::{
+use crate::scalar_funcs::{
     spark_ceil, spark_date_add, spark_date_sub, spark_decimal_div, spark_floor, spark_hex,
     spark_isnan, spark_make_decimal, spark_murmur3_hash, spark_read_side_padding, spark_round,
     spark_unhex, spark_unscaled_value, spark_xxhash64, SparkChrFunc,
 };
+use arrow_schema::DataType;
 use datafusion_common::{DataFusionError, Result as DataFusionResult};
 use datafusion_expr::registry::FunctionRegistry;
 use datafusion_expr::{
diff --git a/native/core/src/execution/datafusion/expressions/correlation.rs b/native/spark-expr/src/correlation.rs
similarity index 98%
rename from native/core/src/execution/datafusion/expressions/correlation.rs
rename to native/spark-expr/src/correlation.rs
index 6bf35e7115..e5f36c6f95 100644
--- a/native/core/src/execution/datafusion/expressions/correlation.rs
+++ b/native/spark-expr/src/correlation.rs
@@ -19,9 +19,8 @@ use arrow::compute::{and, filter, is_not_null};
 
 use std::{any::Any, sync::Arc};
 
-use crate::execution::datafusion::expressions::{
-    covariance::CovarianceAccumulator, stddev::StddevAccumulator,
-};
+use crate::covariance::CovarianceAccumulator;
+use crate::stddev::StddevAccumulator;
 use arrow::{
     array::ArrayRef,
     datatypes::{DataType, Field},
diff --git a/native/core/src/execution/datafusion/expressions/covariance.rs b/native/spark-expr/src/covariance.rs
similarity index 100%
rename from native/core/src/execution/datafusion/expressions/covariance.rs
rename to native/spark-expr/src/covariance.rs
diff --git a/native/spark-expr/src/lib.rs b/native/spark-expr/src/lib.rs
index c227b3a025..15f446ef35 100644
--- a/native/spark-expr/src/lib.rs
+++ b/native/spark-expr/src/lib.rs
@@ -23,18 +23,38 @@ mod cast;
 mod error;
 mod if_expr;
 
+mod avg;
+pub use avg::Avg;
+mod bitwise_not;
+pub use bitwise_not::{bitwise_not, BitwiseNotExpr};
+mod avg_decimal;
+pub use avg_decimal::AvgDecimal;
+mod correlation;
+pub use correlation::Correlation;
+mod covariance;
+pub use covariance::Covariance;
 mod kernels;
 mod list;
 mod regexp;
 pub mod scalar_funcs;
 pub mod spark_hash;
+mod stddev;
+pub use stddev::Stddev;
 mod structs;
+mod sum_decimal;
+pub use sum_decimal::SumDecimal;
+mod normalize_nan;
 mod temporal;
 pub mod timezone;
 mod to_json;
 pub mod utils;
+pub use normalize_nan::NormalizeNaNAndZero;
 
+mod variance;
+pub use variance::Variance;
+mod comet_scalar_funcs;
 pub use cast::{spark_cast, Cast, SparkCastOptions};
+pub use comet_scalar_funcs::create_comet_physical_fun;
 pub use error::{SparkError, SparkResult};
 pub use if_expr::IfExpr;
 pub use list::{ArrayInsert, GetArrayStructFields, ListExtract};
diff --git a/native/core/src/execution/datafusion/expressions/normalize_nan.rs b/native/spark-expr/src/normalize_nan.rs
similarity index 100%
rename from native/core/src/execution/datafusion/expressions/normalize_nan.rs
rename to native/spark-expr/src/normalize_nan.rs
diff --git a/native/core/src/execution/datafusion/expressions/stddev.rs b/native/spark-expr/src/stddev.rs
similarity index 98%
rename from native/core/src/execution/datafusion/expressions/stddev.rs
rename to native/spark-expr/src/stddev.rs
index 1ba495e215..3cf604da0b 100644
--- a/native/core/src/execution/datafusion/expressions/stddev.rs
+++ b/native/spark-expr/src/stddev.rs
@@ -17,7 +17,7 @@
 
 use std::{any::Any, sync::Arc};
 
-use crate::execution::datafusion::expressions::variance::VarianceAccumulator;
+use crate::variance::VarianceAccumulator;
 use arrow::{
     array::ArrayRef,
     datatypes::{DataType, Field},
diff --git a/native/core/src/execution/datafusion/expressions/sum_decimal.rs b/native/spark-expr/src/sum_decimal.rs
similarity index 98%
rename from native/core/src/execution/datafusion/expressions/sum_decimal.rs
rename to native/spark-expr/src/sum_decimal.rs
index d885ff90b6..ab142aee69 100644
--- a/native/core/src/execution/datafusion/expressions/sum_decimal.rs
+++ b/native/spark-expr/src/sum_decimal.rs
@@ -15,8 +15,7 @@
 // specific language governing permissions and limitations
 // under the License.
 
-use crate::execution::datafusion::expressions::checkoverflow::is_valid_decimal_precision;
-use crate::unlikely;
+use crate::utils::{is_valid_decimal_precision, unlikely};
 use arrow::{
     array::BooleanBufferBuilder,
     buffer::{BooleanBuffer, NullBuffer},
@@ -113,7 +112,6 @@ impl AggregateUDFImpl for SumDecimal {
         Ok(Box::new(SumDecimalGroupsAccumulator::new(
             self.result_type.clone(),
             self.precision,
-            self.scale,
         )))
     }
 
@@ -286,18 +284,16 @@ struct SumDecimalGroupsAccumulator {
     sum: Vec<i128>,
     result_type: DataType,
     precision: u8,
-    scale: i8,
 }
 
 impl SumDecimalGroupsAccumulator {
-    fn new(result_type: DataType, precision: u8, scale: i8) -> Self {
+    fn new(result_type: DataType, precision: u8) -> Self {
         Self {
             is_not_null: BooleanBufferBuilder::new(0),
             is_empty: BooleanBufferBuilder::new(0),
             sum: Vec::new(),
             result_type,
             precision,
-            scale,
         }
     }
 
@@ -488,11 +484,11 @@ mod tests {
     use arrow::datatypes::*;
     use arrow_array::builder::{Decimal128Builder, StringBuilder};
     use arrow_array::RecordBatch;
+    use datafusion::execution::TaskContext;
     use datafusion::physical_plan::aggregates::{AggregateExec, AggregateMode, PhysicalGroupBy};
     use datafusion::physical_plan::memory::MemoryExec;
     use datafusion::physical_plan::ExecutionPlan;
     use datafusion_common::Result;
-    use datafusion_execution::TaskContext;
     use datafusion_expr::AggregateUDF;
     use datafusion_physical_expr::aggregate::AggregateExprBuilder;
     use datafusion_physical_expr::expressions::{Column, Literal};
diff --git a/native/spark-expr/src/utils.rs b/native/spark-expr/src/utils.rs
index db4ad1956a..18a2314fb1 100644
--- a/native/spark-expr/src/utils.rs
+++ b/native/spark-expr/src/utils.rs
@@ -19,7 +19,7 @@ use arrow_array::{
     cast::as_primitive_array,
     types::{Int32Type, TimestampMicrosecondType},
 };
-use arrow_schema::{ArrowError, DataType};
+use arrow_schema::{ArrowError, DataType, DECIMAL128_MAX_PRECISION};
 use std::sync::Arc;
 
 use crate::timezone::Tz;
@@ -27,6 +27,7 @@ use arrow::{
     array::{as_dictionary_array, Array, ArrayRef, PrimitiveArray},
     temporal_conversions::as_datetime,
 };
+use arrow_data::decimal::{MAX_DECIMAL_FOR_EACH_PRECISION, MIN_DECIMAL_FOR_EACH_PRECISION};
 use chrono::{DateTime, Offset, TimeZone};
 
 /// Preprocesses input arrays to add timezone information from Spark to Arrow array datatype or
@@ -176,3 +177,39 @@ fn pre_timestamp_cast(array: ArrayRef, timezone: String) -> Result<ArrayRef, Arr
         _ => Ok(array),
     }
 }
+
+/// Adapted from arrow-rs `validate_decimal_precision` but returns bool
+/// instead of Err to avoid the cost of formatting the error strings and is
+/// optimized to remove a memcpy that exists in the original function
+/// we can remove this code once we upgrade to a version of arrow-rs that
+/// includes https://github.com/apache/arrow-rs/pull/6419
+#[inline]
+pub fn is_valid_decimal_precision(value: i128, precision: u8) -> bool {
+    precision <= DECIMAL128_MAX_PRECISION
+        && value >= MIN_DECIMAL_FOR_EACH_PRECISION[precision as usize - 1]
+        && value <= MAX_DECIMAL_FOR_EACH_PRECISION[precision as usize - 1]
+}
+
+// These are borrowed from hashbrown crate:
+//   https://github.com/rust-lang/hashbrown/blob/master/src/raw/mod.rs
+
+// On stable we can use #[cold] to get a equivalent effect: this attributes
+// suggests that the function is unlikely to be called
+#[inline]
+#[cold]
+pub fn cold() {}
+
+#[inline]
+pub fn likely(b: bool) -> bool {
+    if !b {
+        cold();
+    }
+    b
+}
+#[inline]
+pub fn unlikely(b: bool) -> bool {
+    if b {
+        cold();
+    }
+    b
+}
diff --git a/native/core/src/execution/datafusion/expressions/variance.rs b/native/spark-expr/src/variance.rs
similarity index 100%
rename from native/core/src/execution/datafusion/expressions/variance.rs
rename to native/spark-expr/src/variance.rs