refactor: unify function registry (Part 1) (#6262)

* refactor: unify function registry (Part 1)

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

* refactor: simplify via register_scalar

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

---------

Signed-off-by: Zhenchi <zhongzc_arch@outlook.com>

src/common/function/src/aggrs.rs

@@ -12,11 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-mod geo_path;
-mod hll;
-mod uddsketch_state;
-
-pub use geo_path::{GeoPathAccumulator, GEO_PATH_NAME};
-pub(crate) use hll::HllStateType;
-pub use hll::{HllState, HLL_MERGE_NAME, HLL_NAME};
-pub use uddsketch_state::{UddSketchState, UDDSKETCH_MERGE_NAME, UDDSKETCH_STATE_NAME};
+pub mod approximate;
+#[cfg(feature = "geo")]
+pub mod geo;
+pub mod vector;

src/common/function/src/aggrs/approximate.rs

@@ -0,0 +1,32 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed 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::function_registry::FunctionRegistry;
+
+pub(crate) mod hll;
+mod uddsketch;
+
+pub(crate) struct ApproximateFunction;
+
+impl ApproximateFunction {
+    pub fn register(registry: &FunctionRegistry) {
+        // uddsketch
+        registry.register_aggr(uddsketch::UddSketchState::state_udf_impl());
+        registry.register_aggr(uddsketch::UddSketchState::merge_udf_impl());
+
+        // hll
+        registry.register_aggr(hll::HllState::state_udf_impl());
+        registry.register_aggr(hll::HllState::merge_udf_impl());
+    }
+}

src/common/function/src/aggrs/geo.rs

@@ -0,0 +1,27 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed 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::function_registry::FunctionRegistry;
+
+mod encoding;
+mod geo_path;
+
+pub(crate) struct GeoFunction;
+
+impl GeoFunction {
+    pub fn register(registry: &FunctionRegistry) {
+        registry.register_aggr(geo_path::GeoPathAccumulator::uadf_impl());
+        registry.register_aggr(encoding::JsonPathAccumulator::uadf_impl());
+    }
+}

src/common/function/src/aggrs/geo/encoding.rs

@@ -19,9 +19,12 @@ use common_error::status_code::StatusCode;
 use common_macro::{as_aggr_func_creator, AggrFuncTypeStore};
 use common_query::error::{self, InvalidInputStateSnafu, Result};
 use common_query::logical_plan::accumulator::AggrFuncTypeStore;
-use common_query::logical_plan::{Accumulator, AggregateFunctionCreator};
+use common_query::logical_plan::{
+    create_aggregate_function, Accumulator, AggregateFunctionCreator,
+};
 use common_query::prelude::AccumulatorCreatorFunction;
 use common_time::Timestamp;
+use datafusion_expr::AggregateUDF;
 use datatypes::prelude::ConcreteDataType;
 use datatypes::value::{ListValue, Value};
 use datatypes::vectors::VectorRef;
@@ -47,6 +50,16 @@ impl JsonPathAccumulator {
             timestamp_type,
         }
     }
+
+    /// Create a new `AggregateUDF` for the `json_encode_path` aggregate function.
+    pub fn uadf_impl() -> AggregateUDF {
+        create_aggregate_function(
+            "json_encode_path".to_string(),
+            3,
+            Arc::new(JsonPathEncodeFunctionCreator::default()),
+        )
+        .into()
+    }
 }
 
 impl Accumulator for JsonPathAccumulator {

src/common/function/src/aggrs/geo/geo_path.rs

@@ -47,7 +47,7 @@ impl GeoPathAccumulator {
         Self::default()
     }
 
-    pub fn udf_impl() -> AggregateUDF {
+    pub fn uadf_impl() -> AggregateUDF {
         create_udaf(
             GEO_PATH_NAME,
             // Input types: lat, lng, timestamp

src/common/function/src/aggrs/vector.rs

@@ -0,0 +1,29 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed 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::aggrs::vector::product::VectorProduct;
+use crate::aggrs::vector::sum::VectorSum;
+use crate::function_registry::FunctionRegistry;
+
+mod product;
+mod sum;
+
+pub(crate) struct VectorFunction;
+
+impl VectorFunction {
+    pub fn register(registry: &FunctionRegistry) {
+        registry.register_aggr(VectorSum::uadf_impl());
+        registry.register_aggr(VectorProduct::uadf_impl());
+    }
+}

src/common/function/src/aggrs/vector/product.rs

@@ -16,8 +16,11 @@ use std::sync::Arc;
 
 use common_macro::{as_aggr_func_creator, AggrFuncTypeStore};
 use common_query::error::{CreateAccumulatorSnafu, Error, InvalidFuncArgsSnafu};
-use common_query::logical_plan::{Accumulator, AggregateFunctionCreator};
+use common_query::logical_plan::{
+    create_aggregate_function, Accumulator, AggregateFunctionCreator,
+};
 use common_query::prelude::AccumulatorCreatorFunction;
+use datafusion_expr::AggregateUDF;
 use datatypes::prelude::{ConcreteDataType, Value, *};
 use datatypes::vectors::VectorRef;
 use nalgebra::{Const, DVectorView, Dyn, OVector};
@@ -75,6 +78,16 @@ impl AggregateFunctionCreator for VectorProductCreator {
 }
 
 impl VectorProduct {
+    /// Create a new `AggregateUDF` for the `vec_product` aggregate function.
+    pub fn uadf_impl() -> AggregateUDF {
+        create_aggregate_function(
+            "vec_product".to_string(),
+            1,
+            Arc::new(VectorProductCreator::default()),
+        )
+        .into()
+    }
+
     fn inner(&mut self, len: usize) -> &mut OVector<f32, Dyn> {
         self.product.get_or_insert_with(|| {
             OVector::from_iterator_generic(Dyn(len), Const::<1>, (0..len).map(|_| 1.0))

src/common/function/src/aggrs/vector/sum.rs

@@ -16,8 +16,11 @@ use std::sync::Arc;
 
 use common_macro::{as_aggr_func_creator, AggrFuncTypeStore};
 use common_query::error::{CreateAccumulatorSnafu, Error, InvalidFuncArgsSnafu};
-use common_query::logical_plan::{Accumulator, AggregateFunctionCreator};
+use common_query::logical_plan::{
+    create_aggregate_function, Accumulator, AggregateFunctionCreator,
+};
 use common_query::prelude::AccumulatorCreatorFunction;
+use datafusion_expr::AggregateUDF;
 use datatypes::prelude::{ConcreteDataType, Value, *};
 use datatypes::vectors::VectorRef;
 use nalgebra::{Const, DVectorView, Dyn, OVector};
@@ -25,6 +28,7 @@ use snafu::ensure;
 
 use crate::scalars::vector::impl_conv::{as_veclit, as_veclit_if_const, veclit_to_binlit};
 
+/// The accumulator for the `vec_sum` aggregate function.
 #[derive(Debug, Default)]
 pub struct VectorSum {
     sum: Option<OVector<f32, Dyn>>,
@@ -74,6 +78,16 @@ impl AggregateFunctionCreator for VectorSumCreator {
 }
 
 impl VectorSum {
+    /// Create a new `AggregateUDF` for the `vec_sum` aggregate function.
+    pub fn uadf_impl() -> AggregateUDF {
+        create_aggregate_function(
+            "vec_sum".to_string(),
+            1,
+            Arc::new(VectorSumCreator::default()),
+        )
+        .into()
+    }
+
     fn inner(&mut self, len: usize) -> &mut OVector<f32, Dyn> {
         self.sum
             .get_or_insert_with(|| OVector::zeros_generic(Dyn(len), Const::<1>))

src/common/function/src/function_factory.rs

@@ -0,0 +1,63 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed 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 std::sync::Arc;
+
+use datafusion_expr::ScalarUDF;
+
+use crate::function::{FunctionContext, FunctionRef};
+use crate::scalars::udf::create_udf;
+
+/// A factory for creating `ScalarUDF` that require a function context.
+#[derive(Clone)]
+pub struct ScalarFunctionFactory {
+    name: String,
+    factory: Arc<dyn Fn(FunctionContext) -> ScalarUDF + Send + Sync>,
+}
+
+impl ScalarFunctionFactory {
+    /// Returns the name of the function.
+    pub fn name(&self) -> &str {
+        &self.name
+    }
+
+    /// Returns a `ScalarUDF` when given a function context.
+    pub fn provide(&self, ctx: FunctionContext) -> ScalarUDF {
+        (self.factory)(ctx)
+    }
+}
+
+impl From<ScalarUDF> for ScalarFunctionFactory {
+    fn from(df_udf: ScalarUDF) -> Self {
+        let name = df_udf.name().to_string();
+        let func = Arc::new(move |_ctx| df_udf.clone());
+        Self {
+            name,
+            factory: func,
+        }
+    }
+}
+
+impl From<FunctionRef> for ScalarFunctionFactory {
+    fn from(func: FunctionRef) -> Self {
+        let name = func.name().to_string();
+        let func = Arc::new(move |ctx: FunctionContext| {
+            create_udf(func.clone(), ctx.query_ctx, ctx.state)
+        });
+        Self {
+            name,
+            factory: func,
+        }
+    }
+}

src/common/function/src/function_registry.rs

@@ -16,11 +16,14 @@
 use std::collections::HashMap;
 use std::sync::{Arc, RwLock};
 
+use datafusion_expr::AggregateUDF;
 use once_cell::sync::Lazy;
 
 use crate::admin::AdminFunction;
-use crate::function::{AsyncFunctionRef, FunctionRef};
-use crate::scalars::aggregate::{AggregateFunctionMetaRef, AggregateFunctions};
+use crate::aggrs::approximate::ApproximateFunction;
+use crate::aggrs::vector::VectorFunction as VectorAggrFunction;
+use crate::function::{AsyncFunctionRef, Function, FunctionRef};
+use crate::function_factory::ScalarFunctionFactory;
 use crate::scalars::date::DateFunction;
 use crate::scalars::expression::ExpressionFunction;
 use crate::scalars::hll_count::HllCalcFunction;
@@ -31,18 +34,19 @@ use crate::scalars::matches_term::MatchesTermFunction;
 use crate::scalars::math::MathFunction;
 use crate::scalars::timestamp::TimestampFunction;
 use crate::scalars::uddsketch_calc::UddSketchCalcFunction;
-use crate::scalars::vector::VectorFunction;
+use crate::scalars::vector::VectorFunction as VectorScalarFunction;
 use crate::system::SystemFunction;
 
 #[derive(Default)]
 pub struct FunctionRegistry {
-    functions: RwLock<HashMap<String, FunctionRef>>,
+    functions: RwLock<HashMap<String, ScalarFunctionFactory>>,
     async_functions: RwLock<HashMap<String, AsyncFunctionRef>>,
-    aggregate_functions: RwLock<HashMap<String, AggregateFunctionMetaRef>>,
+    aggregate_functions: RwLock<HashMap<String, AggregateUDF>>,
 }
 
 impl FunctionRegistry {
-    pub fn register(&self, func: FunctionRef) {
+    pub fn register(&self, func: impl Into<ScalarFunctionFactory>) {
+        let func = func.into();
         let _ = self
             .functions
             .write()
@@ -50,6 +54,10 @@ impl FunctionRegistry {
             .insert(func.name().to_string(), func);
     }
 
+    pub fn register_scalar(&self, func: impl Function + 'static) {
+        self.register(Arc::new(func) as FunctionRef);
+    }
+
     pub fn register_async(&self, func: AsyncFunctionRef) {
         let _ = self
             .async_functions
@@ -58,6 +66,14 @@ impl FunctionRegistry {
             .insert(func.name().to_string(), func);
     }
 
+    pub fn register_aggr(&self, func: AggregateUDF) {
+        let _ = self
+            .aggregate_functions
+            .write()
+            .unwrap()
+            .insert(func.name().to_string(), func);
+    }
+
     pub fn get_async_function(&self, name: &str) -> Option<AsyncFunctionRef> {
         self.async_functions.read().unwrap().get(name).cloned()
     }
@@ -71,27 +87,16 @@ impl FunctionRegistry {
             .collect()
     }
 
-    pub fn register_aggregate_function(&self, func: AggregateFunctionMetaRef) {
-        let _ = self
-            .aggregate_functions
-            .write()
-            .unwrap()
-            .insert(func.name(), func);
-    }
-
-    pub fn get_aggr_function(&self, name: &str) -> Option<AggregateFunctionMetaRef> {
-        self.aggregate_functions.read().unwrap().get(name).cloned()
-    }
-
-    pub fn get_function(&self, name: &str) -> Option<FunctionRef> {
+    #[cfg(test)]
+    pub fn get_function(&self, name: &str) -> Option<ScalarFunctionFactory> {
         self.functions.read().unwrap().get(name).cloned()
     }
 
-    pub fn functions(&self) -> Vec<FunctionRef> {
+    pub fn scalar_functions(&self) -> Vec<ScalarFunctionFactory> {
         self.functions.read().unwrap().values().cloned().collect()
     }
 
-    pub fn aggregate_functions(&self) -> Vec<AggregateFunctionMetaRef> {
+    pub fn aggregate_functions(&self) -> Vec<AggregateUDF> {
         self.aggregate_functions
             .read()
             .unwrap()
@@ -112,9 +117,6 @@ pub static FUNCTION_REGISTRY: Lazy<Arc<FunctionRegistry>> = Lazy::new(|| {
     UddSketchCalcFunction::register(&function_registry);
     HllCalcFunction::register(&function_registry);
 
-    // Aggregate functions
-    AggregateFunctions::register(&function_registry);
-
     // Full text search function
     MatchesFunction::register(&function_registry);
     MatchesTermFunction::register(&function_registry);
@@ -127,15 +129,21 @@ pub static FUNCTION_REGISTRY: Lazy<Arc<FunctionRegistry>> = Lazy::new(|| {
     JsonFunction::register(&function_registry);
 
     // Vector related functions
-    VectorFunction::register(&function_registry);
+    VectorScalarFunction::register(&function_registry);
+    VectorAggrFunction::register(&function_registry);
 
     // Geo functions
     #[cfg(feature = "geo")]
     crate::scalars::geo::GeoFunctions::register(&function_registry);
+    #[cfg(feature = "geo")]
+    crate::aggrs::geo::GeoFunction::register(&function_registry);
 
     // Ip functions
     IpFunctions::register(&function_registry);
 
+    // Approximate functions
+    ApproximateFunction::register(&function_registry);
+
     Arc::new(function_registry)
 });
 
@@ -147,12 +155,11 @@ mod tests {
     #[test]
     fn test_function_registry() {
         let registry = FunctionRegistry::default();
-        let func = Arc::new(TestAndFunction);
 
         assert!(registry.get_function("test_and").is_none());
-        assert!(registry.functions().is_empty());
-        registry.register(func);
+        assert!(registry.scalar_functions().is_empty());
+        registry.register_scalar(TestAndFunction);
         let _ = registry.get_function("test_and").unwrap();
-        assert_eq!(1, registry.functions().len());
+        assert_eq!(1, registry.scalar_functions().len());
     }
 }

src/common/function/src/lib.rs

@@ -18,13 +18,14 @@
 mod admin;
 mod flush_flow;
 mod macros;
-pub mod scalars;
 mod system;
 
-pub mod aggr;
+pub mod aggrs;
 pub mod function;
+pub mod function_factory;
 pub mod function_registry;
 pub mod handlers;
 pub mod helper;
+pub mod scalars;
 pub mod state;
 pub mod utils;

src/common/function/src/scalars.rs

@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-pub mod aggregate;
 pub(crate) mod date;
 pub mod expression;
 #[cfg(feature = "geo")]

src/common/function/src/scalars/aggregate.rs

@@ -1,89 +0,0 @@
-// Copyright 2023 Greptime Team
-//
-// Licensed 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.
-
-//! # Deprecate Warning:
-//!
-//! This module is deprecated and will be removed in the future.
-//! All UDAF implementation here are not maintained and should
-//! not be used before they are refactored into the `src/aggr`
-//! version.
-
-use std::sync::Arc;
-
-use common_query::logical_plan::AggregateFunctionCreatorRef;
-
-use crate::function_registry::FunctionRegistry;
-use crate::scalars::vector::product::VectorProductCreator;
-use crate::scalars::vector::sum::VectorSumCreator;
-
-/// A function creates `AggregateFunctionCreator`.
-/// "Aggregator" *is* AggregatorFunction. Since the later one is long, we named an short alias for it.
-/// The two names might be used interchangeably.
-type AggregatorCreatorFunction = Arc<dyn Fn() -> AggregateFunctionCreatorRef + Send + Sync>;
-
-/// `AggregateFunctionMeta` dynamically creates AggregateFunctionCreator.
-#[derive(Clone)]
-pub struct AggregateFunctionMeta {
-    name: String,
-    args_count: u8,
-    creator: AggregatorCreatorFunction,
-}
-
-pub type AggregateFunctionMetaRef = Arc<AggregateFunctionMeta>;
-
-impl AggregateFunctionMeta {
-    pub fn new(name: &str, args_count: u8, creator: AggregatorCreatorFunction) -> Self {
-        Self {
-            name: name.to_string(),
-            args_count,
-            creator,
-        }
-    }
-
-    pub fn name(&self) -> String {
-        self.name.to_string()
-    }
-
-    pub fn args_count(&self) -> u8 {
-        self.args_count
-    }
-
-    pub fn create(&self) -> AggregateFunctionCreatorRef {
-        (self.creator)()
-    }
-}
-
-pub(crate) struct AggregateFunctions;
-
-impl AggregateFunctions {
-    pub fn register(registry: &FunctionRegistry) {
-        registry.register_aggregate_function(Arc::new(AggregateFunctionMeta::new(
-            "vec_sum",
-            1,
-            Arc::new(|| Arc::new(VectorSumCreator::default())),
-        )));
-        registry.register_aggregate_function(Arc::new(AggregateFunctionMeta::new(
-            "vec_product",
-            1,
-            Arc::new(|| Arc::new(VectorProductCreator::default())),
-        )));
-
-        #[cfg(feature = "geo")]
-        registry.register_aggregate_function(Arc::new(AggregateFunctionMeta::new(
-            "json_encode_path",
-            3,
-            Arc::new(|| Arc::new(super::geo::encoding::JsonPathEncodeFunctionCreator::default())),
-        )));
-    }
-}

src/common/function/src/scalars/date.rs

@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::sync::Arc;
 mod date_add;
 mod date_format;
 mod date_sub;
@@ -27,8 +26,8 @@ pub(crate) struct DateFunction;
 
 impl DateFunction {
     pub fn register(registry: &FunctionRegistry) {
-        registry.register(Arc::new(DateAddFunction));
-        registry.register(Arc::new(DateSubFunction));
-        registry.register(Arc::new(DateFormatFunction));
+        registry.register_scalar(DateAddFunction);
+        registry.register_scalar(DateSubFunction);
+        registry.register_scalar(DateFormatFunction);
     }
 }

src/common/function/src/scalars/expression.rs

@@ -17,8 +17,6 @@ mod ctx;
 mod is_null;
 mod unary;
 
-use std::sync::Arc;
-
 pub use binary::scalar_binary_op;
 pub use ctx::EvalContext;
 pub use unary::scalar_unary_op;
@@ -30,6 +28,6 @@ pub(crate) struct ExpressionFunction;
 
 impl ExpressionFunction {
     pub fn register(registry: &FunctionRegistry) {
-        registry.register(Arc::new(IsNullFunction));
+        registry.register_scalar(IsNullFunction);
     }
 }

src/common/function/src/scalars/geo.rs

@@ -12,11 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::sync::Arc;
-pub(crate) mod encoding;
 mod geohash;
 mod h3;
-mod helpers;
+pub(crate) mod helpers;
 mod measure;
 mod relation;
 mod s2;
@@ -29,57 +27,57 @@ pub(crate) struct GeoFunctions;
 impl GeoFunctions {
     pub fn register(registry: &FunctionRegistry) {
         // geohash
-        registry.register(Arc::new(geohash::GeohashFunction));
-        registry.register(Arc::new(geohash::GeohashNeighboursFunction));
+        registry.register_scalar(geohash::GeohashFunction);
+        registry.register_scalar(geohash::GeohashNeighboursFunction);
 
         // h3 index
-        registry.register(Arc::new(h3::H3LatLngToCell));
-        registry.register(Arc::new(h3::H3LatLngToCellString));
+        registry.register_scalar(h3::H3LatLngToCell);
+        registry.register_scalar(h3::H3LatLngToCellString);
 
         // h3 index inspection
-        registry.register(Arc::new(h3::H3CellBase));
-        registry.register(Arc::new(h3::H3CellIsPentagon));
-        registry.register(Arc::new(h3::H3StringToCell));
-        registry.register(Arc::new(h3::H3CellToString));
-        registry.register(Arc::new(h3::H3CellCenterLatLng));
-        registry.register(Arc::new(h3::H3CellResolution));
+        registry.register_scalar(h3::H3CellBase);
+        registry.register_scalar(h3::H3CellIsPentagon);
+        registry.register_scalar(h3::H3StringToCell);
+        registry.register_scalar(h3::H3CellToString);
+        registry.register_scalar(h3::H3CellCenterLatLng);
+        registry.register_scalar(h3::H3CellResolution);
 
         // h3 hierarchical grid
-        registry.register(Arc::new(h3::H3CellCenterChild));
-        registry.register(Arc::new(h3::H3CellParent));
-        registry.register(Arc::new(h3::H3CellToChildren));
-        registry.register(Arc::new(h3::H3CellToChildrenSize));
-        registry.register(Arc::new(h3::H3CellToChildPos));
-        registry.register(Arc::new(h3::H3ChildPosToCell));
-        registry.register(Arc::new(h3::H3CellContains));
+        registry.register_scalar(h3::H3CellCenterChild);
+        registry.register_scalar(h3::H3CellParent);
+        registry.register_scalar(h3::H3CellToChildren);
+        registry.register_scalar(h3::H3CellToChildrenSize);
+        registry.register_scalar(h3::H3CellToChildPos);
+        registry.register_scalar(h3::H3ChildPosToCell);
+        registry.register_scalar(h3::H3CellContains);
 
         // h3 grid traversal
-        registry.register(Arc::new(h3::H3GridDisk));
-        registry.register(Arc::new(h3::H3GridDiskDistances));
-        registry.register(Arc::new(h3::H3GridDistance));
-        registry.register(Arc::new(h3::H3GridPathCells));
+        registry.register_scalar(h3::H3GridDisk);
+        registry.register_scalar(h3::H3GridDiskDistances);
+        registry.register_scalar(h3::H3GridDistance);
+        registry.register_scalar(h3::H3GridPathCells);
 
         // h3 measurement
-        registry.register(Arc::new(h3::H3CellDistanceSphereKm));
-        registry.register(Arc::new(h3::H3CellDistanceEuclideanDegree));
+        registry.register_scalar(h3::H3CellDistanceSphereKm);
+        registry.register_scalar(h3::H3CellDistanceEuclideanDegree);
 
         // s2
-        registry.register(Arc::new(s2::S2LatLngToCell));
-        registry.register(Arc::new(s2::S2CellLevel));
-        registry.register(Arc::new(s2::S2CellToToken));
-        registry.register(Arc::new(s2::S2CellParent));
+        registry.register_scalar(s2::S2LatLngToCell);
+        registry.register_scalar(s2::S2CellLevel);
+        registry.register_scalar(s2::S2CellToToken);
+        registry.register_scalar(s2::S2CellParent);
 
         // spatial data type
-        registry.register(Arc::new(wkt::LatLngToPointWkt));
+        registry.register_scalar(wkt::LatLngToPointWkt);
 
         // spatial relation
-        registry.register(Arc::new(relation::STContains));
-        registry.register(Arc::new(relation::STWithin));
-        registry.register(Arc::new(relation::STIntersects));
+        registry.register_scalar(relation::STContains);
+        registry.register_scalar(relation::STWithin);
+        registry.register_scalar(relation::STIntersects);
 
         // spatial measure
-        registry.register(Arc::new(measure::STDistance));
-        registry.register(Arc::new(measure::STDistanceSphere));
-        registry.register(Arc::new(measure::STArea));
+        registry.register_scalar(measure::STDistance);
+        registry.register_scalar(measure::STDistanceSphere);
+        registry.register_scalar(measure::STArea);
     }
 }

src/common/function/src/scalars/geo/helpers.rs

@@ -37,7 +37,7 @@ macro_rules! ensure_columns_len {
     };
 }
 
-pub(super) use ensure_columns_len;
+pub(crate) use ensure_columns_len;
 
 macro_rules! ensure_columns_n {
     ($columns:ident, $n:literal) => {
@@ -58,7 +58,7 @@ macro_rules! ensure_columns_n {
     };
 }
 
-pub(super) use ensure_columns_n;
+pub(crate) use ensure_columns_n;
 
 macro_rules! ensure_and_coerce {
     ($compare:expr, $coerce:expr) => {{
@@ -72,4 +72,4 @@ macro_rules! ensure_and_coerce {
     }};
 }
 
-pub(super) use ensure_and_coerce;
+pub(crate) use ensure_and_coerce;

src/common/function/src/scalars/hll_count.rs

@@ -16,7 +16,6 @@
 
 use std::fmt;
 use std::fmt::Display;
-use std::sync::Arc;
 
 use common_query::error::{DowncastVectorSnafu, InvalidFuncArgsSnafu, Result};
 use common_query::prelude::{Signature, Volatility};
@@ -27,7 +26,7 @@ use datatypes::vectors::{BinaryVector, MutableVector, UInt64VectorBuilder, Vecto
 use hyperloglogplus::HyperLogLog;
 use snafu::OptionExt;
 
-use crate::aggr::HllStateType;
+use crate::aggrs::approximate::hll::HllStateType;
 use crate::function::{Function, FunctionContext};
 use crate::function_registry::FunctionRegistry;
 
@@ -44,7 +43,7 @@ pub struct HllCalcFunction;
 
 impl HllCalcFunction {
     pub fn register(registry: &FunctionRegistry) {
-        registry.register(Arc::new(HllCalcFunction));
+        registry.register_scalar(HllCalcFunction);
     }
 }
 
@@ -117,6 +116,8 @@ impl Function for HllCalcFunction {
 
 #[cfg(test)]
 mod tests {
+    use std::sync::Arc;
+
     use datatypes::vectors::BinaryVector;
 
     use super::*;

src/common/function/src/scalars/ip.rs

@@ -17,8 +17,6 @@ mod ipv4;
 mod ipv6;
 mod range;
 
-use std::sync::Arc;
-
 use cidr::{Ipv4ToCidr, Ipv6ToCidr};
 use ipv4::{Ipv4NumToString, Ipv4StringToNum};
 use ipv6::{Ipv6NumToString, Ipv6StringToNum};
@@ -31,15 +29,15 @@ pub(crate) struct IpFunctions;
 impl IpFunctions {
     pub fn register(registry: &FunctionRegistry) {
         // Register IPv4 functions
-        registry.register(Arc::new(Ipv4NumToString));
-        registry.register(Arc::new(Ipv4StringToNum));
-        registry.register(Arc::new(Ipv4ToCidr));
-        registry.register(Arc::new(Ipv4InRange));
+        registry.register_scalar(Ipv4NumToString);
+        registry.register_scalar(Ipv4StringToNum);
+        registry.register_scalar(Ipv4ToCidr);
+        registry.register_scalar(Ipv4InRange);
 
         // Register IPv6 functions
-        registry.register(Arc::new(Ipv6NumToString));
-        registry.register(Arc::new(Ipv6StringToNum));
-        registry.register(Arc::new(Ipv6ToCidr));
-        registry.register(Arc::new(Ipv6InRange));
+        registry.register_scalar(Ipv6NumToString);
+        registry.register_scalar(Ipv6StringToNum);
+        registry.register_scalar(Ipv6ToCidr);
+        registry.register_scalar(Ipv6InRange);
     }
 }

src/common/function/src/scalars/json.rs

@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::sync::Arc;
 pub mod json_get;
 mod json_is;
 mod json_path_exists;
@@ -33,23 +32,23 @@ pub(crate) struct JsonFunction;
 
 impl JsonFunction {
     pub fn register(registry: &FunctionRegistry) {
-        registry.register(Arc::new(JsonToStringFunction));
-        registry.register(Arc::new(ParseJsonFunction));
+        registry.register_scalar(JsonToStringFunction);
+        registry.register_scalar(ParseJsonFunction);
 
-        registry.register(Arc::new(JsonGetInt));
-        registry.register(Arc::new(JsonGetFloat));
-        registry.register(Arc::new(JsonGetString));
-        registry.register(Arc::new(JsonGetBool));
+        registry.register_scalar(JsonGetInt);
+        registry.register_scalar(JsonGetFloat);
+        registry.register_scalar(JsonGetString);
+        registry.register_scalar(JsonGetBool);
 
-        registry.register(Arc::new(JsonIsNull));
-        registry.register(Arc::new(JsonIsInt));
-        registry.register(Arc::new(JsonIsFloat));
-        registry.register(Arc::new(JsonIsString));
-        registry.register(Arc::new(JsonIsBool));
-        registry.register(Arc::new(JsonIsArray));
-        registry.register(Arc::new(JsonIsObject));
+        registry.register_scalar(JsonIsNull);
+        registry.register_scalar(JsonIsInt);
+        registry.register_scalar(JsonIsFloat);
+        registry.register_scalar(JsonIsString);
+        registry.register_scalar(JsonIsBool);
+        registry.register_scalar(JsonIsArray);
+        registry.register_scalar(JsonIsObject);
 
-        registry.register(Arc::new(json_path_exists::JsonPathExistsFunction));
-        registry.register(Arc::new(json_path_match::JsonPathMatchFunction));
+        registry.register_scalar(json_path_exists::JsonPathExistsFunction);
+        registry.register_scalar(json_path_match::JsonPathMatchFunction);
     }
 }

src/common/function/src/scalars/matches.rs

@@ -38,11 +38,11 @@ use crate::function_registry::FunctionRegistry;
 ///
 /// Usage: matches(`<col>`, `<pattern>`) -> boolean
 #[derive(Clone, Debug, Default)]
-pub(crate) struct MatchesFunction;
+pub struct MatchesFunction;
 
 impl MatchesFunction {
     pub fn register(registry: &FunctionRegistry) {
-        registry.register(Arc::new(MatchesFunction));
+        registry.register_scalar(MatchesFunction);
     }
 }
 

src/common/function/src/scalars/matches_term.rs

@@ -77,7 +77,7 @@ pub struct MatchesTermFunction;
 
 impl MatchesTermFunction {
     pub fn register(registry: &FunctionRegistry) {
-        registry.register(Arc::new(MatchesTermFunction));
+        registry.register_scalar(MatchesTermFunction);
     }
 }
 

src/common/function/src/scalars/math.rs

@@ -18,7 +18,6 @@ mod pow;
 mod rate;
 
 use std::fmt;
-use std::sync::Arc;
 
 pub use clamp::{ClampFunction, ClampMaxFunction, ClampMinFunction};
 use common_query::error::{GeneralDataFusionSnafu, Result};
@@ -39,13 +38,13 @@ pub(crate) struct MathFunction;
 
 impl MathFunction {
     pub fn register(registry: &FunctionRegistry) {
-        registry.register(Arc::new(ModuloFunction));
-        registry.register(Arc::new(PowFunction));
-        registry.register(Arc::new(RateFunction));
-        registry.register(Arc::new(RangeFunction));
-        registry.register(Arc::new(ClampFunction));
-        registry.register(Arc::new(ClampMinFunction));
-        registry.register(Arc::new(ClampMaxFunction));
+        registry.register_scalar(ModuloFunction);
+        registry.register_scalar(PowFunction);
+        registry.register_scalar(RateFunction);
+        registry.register_scalar(RangeFunction);
+        registry.register_scalar(ClampFunction);
+        registry.register_scalar(ClampMinFunction);
+        registry.register_scalar(ClampMaxFunction);
     }
 }
 

src/common/function/src/scalars/timestamp.rs

@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::sync::Arc;
 mod to_unixtime;
 
 use to_unixtime::ToUnixtimeFunction;
@@ -23,6 +22,6 @@ pub(crate) struct TimestampFunction;
 
 impl TimestampFunction {
     pub fn register(registry: &FunctionRegistry) {
-        registry.register(Arc::new(ToUnixtimeFunction));
+        registry.register_scalar(ToUnixtimeFunction);
     }
 }

src/common/function/src/scalars/uddsketch_calc.rs

@@ -16,7 +16,6 @@
 
 use std::fmt;
 use std::fmt::Display;
-use std::sync::Arc;
 
 use common_query::error::{DowncastVectorSnafu, InvalidFuncArgsSnafu, Result};
 use common_query::prelude::{Signature, Volatility};
@@ -44,7 +43,7 @@ pub struct UddSketchCalcFunction;
 
 impl UddSketchCalcFunction {
     pub fn register(registry: &FunctionRegistry) {
-        registry.register(Arc::new(UddSketchCalcFunction));
+        registry.register_scalar(UddSketchCalcFunction);
     }
 }
 

src/common/function/src/scalars/vector.rs

@@ -17,10 +17,8 @@ mod distance;
 mod elem_product;
 mod elem_sum;
 pub mod impl_conv;
-pub(crate) mod product;
 mod scalar_add;
 mod scalar_mul;
-pub(crate) mod sum;
 mod vector_add;
 mod vector_dim;
 mod vector_div;
@@ -30,37 +28,34 @@ mod vector_norm;
 mod vector_sub;
 mod vector_subvector;
 
-use std::sync::Arc;
-
 use crate::function_registry::FunctionRegistry;
-
 pub(crate) struct VectorFunction;
 
 impl VectorFunction {
     pub fn register(registry: &FunctionRegistry) {
         // conversion
-        registry.register(Arc::new(convert::ParseVectorFunction));
-        registry.register(Arc::new(convert::VectorToStringFunction));
+        registry.register_scalar(convert::ParseVectorFunction);
+        registry.register_scalar(convert::VectorToStringFunction);
 
         // distance
-        registry.register(Arc::new(distance::CosDistanceFunction));
-        registry.register(Arc::new(distance::DotProductFunction));
-        registry.register(Arc::new(distance::L2SqDistanceFunction));
+        registry.register_scalar(distance::CosDistanceFunction);
+        registry.register_scalar(distance::DotProductFunction);
+        registry.register_scalar(distance::L2SqDistanceFunction);
 
         // scalar calculation
-        registry.register(Arc::new(scalar_add::ScalarAddFunction));
-        registry.register(Arc::new(scalar_mul::ScalarMulFunction));
+        registry.register_scalar(scalar_add::ScalarAddFunction);
+        registry.register_scalar(scalar_mul::ScalarMulFunction);
 
         // vector calculation
-        registry.register(Arc::new(vector_add::VectorAddFunction));
-        registry.register(Arc::new(vector_sub::VectorSubFunction));
-        registry.register(Arc::new(vector_mul::VectorMulFunction));
-        registry.register(Arc::new(vector_div::VectorDivFunction));
-        registry.register(Arc::new(vector_norm::VectorNormFunction));
-        registry.register(Arc::new(vector_dim::VectorDimFunction));
-        registry.register(Arc::new(vector_kth_elem::VectorKthElemFunction));
-        registry.register(Arc::new(vector_subvector::VectorSubvectorFunction));
-        registry.register(Arc::new(elem_sum::ElemSumFunction));
-        registry.register(Arc::new(elem_product::ElemProductFunction));
+        registry.register_scalar(vector_add::VectorAddFunction);
+        registry.register_scalar(vector_sub::VectorSubFunction);
+        registry.register_scalar(vector_mul::VectorMulFunction);
+        registry.register_scalar(vector_div::VectorDivFunction);
+        registry.register_scalar(vector_norm::VectorNormFunction);
+        registry.register_scalar(vector_dim::VectorDimFunction);
+        registry.register_scalar(vector_kth_elem::VectorKthElemFunction);
+        registry.register_scalar(vector_subvector::VectorSubvectorFunction);
+        registry.register_scalar(elem_sum::ElemSumFunction);
+        registry.register_scalar(elem_product::ElemProductFunction);
     }
 }

src/common/function/src/system.rs

@@ -36,13 +36,13 @@ pub(crate) struct SystemFunction;
 
 impl SystemFunction {
     pub fn register(registry: &FunctionRegistry) {
-        registry.register(Arc::new(BuildFunction));
-        registry.register(Arc::new(VersionFunction));
-        registry.register(Arc::new(CurrentSchemaFunction));
-        registry.register(Arc::new(DatabaseFunction));
-        registry.register(Arc::new(SessionUserFunction));
-        registry.register(Arc::new(ReadPreferenceFunction));
-        registry.register(Arc::new(TimezoneFunction));
+        registry.register_scalar(BuildFunction);
+        registry.register_scalar(VersionFunction);
+        registry.register_scalar(CurrentSchemaFunction);
+        registry.register_scalar(DatabaseFunction);
+        registry.register_scalar(SessionUserFunction);
+        registry.register_scalar(ReadPreferenceFunction);
+        registry.register_scalar(TimezoneFunction);
         registry.register_async(Arc::new(ProcedureStateFunction));
         PGCatalogFunction::register(registry);
     }

src/common/function/src/system/pg_catalog.rs

@@ -16,8 +16,6 @@ mod pg_get_userbyid;
 mod table_is_visible;
 mod version;
 
-use std::sync::Arc;
-
 use pg_get_userbyid::PGGetUserByIdFunction;
 use table_is_visible::PGTableIsVisibleFunction;
 use version::PGVersionFunction;
@@ -35,8 +33,8 @@ pub(super) struct PGCatalogFunction;
 
 impl PGCatalogFunction {
     pub fn register(registry: &FunctionRegistry) {
-        registry.register(Arc::new(PGTableIsVisibleFunction));
-        registry.register(Arc::new(PGGetUserByIdFunction));
-        registry.register(Arc::new(PGVersionFunction));
+        registry.register_scalar(PGTableIsVisibleFunction);
+        registry.register_scalar(PGGetUserByIdFunction);
+        registry.register_scalar(PGVersionFunction);
     }
 }

src/datanode/src/tests.rs

@@ -19,12 +19,11 @@ use std::time::Duration;
 use api::region::RegionResponse;
 use async_trait::async_trait;
 use common_error::ext::BoxedError;
-use common_function::function::FunctionRef;
-use common_function::scalars::aggregate::AggregateFunctionMetaRef;
+use common_function::function_factory::ScalarFunctionFactory;
 use common_query::Output;
 use common_runtime::runtime::{BuilderBuild, RuntimeTrait};
 use common_runtime::Runtime;
-use datafusion_expr::LogicalPlan;
+use datafusion_expr::{AggregateUDF, LogicalPlan};
 use query::dataframe::DataFrame;
 use query::planner::LogicalPlanner;
 use query::query_engine::{DescribeResult, QueryEngineState};
@@ -76,9 +75,9 @@ impl QueryEngine for MockQueryEngine {
         unimplemented!()
     }
 
-    fn register_aggregate_function(&self, _func: AggregateFunctionMetaRef) {}
+    fn register_aggregate_function(&self, _func: AggregateUDF) {}
 
-    fn register_function(&self, _func: FunctionRef) {}
+    fn register_scalar_function(&self, _func: ScalarFunctionFactory) {}
 
     fn read_table(&self, _table: TableRef) -> query::error::Result<DataFrame> {
         unimplemented!()

src/flow/src/transform.rs

@@ -17,7 +17,7 @@ use std::collections::BTreeMap;
 use std::sync::Arc;
 
 use common_error::ext::BoxedError;
-use common_function::function::FunctionContext;
+use common_function::function::{FunctionContext, FunctionRef};
 use datafusion_substrait::extensions::Extensions;
 use datatypes::data_type::ConcreteDataType as CDT;
 use query::QueryEngine;
@@ -108,9 +108,13 @@ impl FunctionExtensions {
 
 /// register flow-specific functions to the query engine
 pub fn register_function_to_query_engine(engine: &Arc<dyn QueryEngine>) {
-    engine.register_function(Arc::new(TumbleFunction::new("tumble")));
-    engine.register_function(Arc::new(TumbleFunction::new(TUMBLE_START)));
-    engine.register_function(Arc::new(TumbleFunction::new(TUMBLE_END)));
+    let tumble_fn = Arc::new(TumbleFunction::new("tumble")) as FunctionRef;
+    let tumble_start_fn = Arc::new(TumbleFunction::new(TUMBLE_START)) as FunctionRef;
+    let tumble_end_fn = Arc::new(TumbleFunction::new(TUMBLE_END)) as FunctionRef;
+
+    engine.register_scalar_function(tumble_fn.into());
+    engine.register_scalar_function(tumble_start_fn.into());
+    engine.register_scalar_function(tumble_end_fn.into());
 }
 
 #[derive(Debug)]

src/mito2/src/sst/index/fulltext_index/applier/builder.rs

@@ -282,14 +282,15 @@ mod tests {
     use std::sync::Arc;
 
     use api::v1::SemanticType;
-    use common_function::function_registry::FUNCTION_REGISTRY;
-    use common_function::scalars::udf::create_udf;
+    use common_function::function::FunctionRef;
+    use common_function::function_factory::ScalarFunctionFactory;
+    use common_function::scalars::matches::MatchesFunction;
+    use common_function::scalars::matches_term::MatchesTermFunction;
     use datafusion::functions::string::lower;
     use datafusion_common::Column;
     use datafusion_expr::expr::ScalarFunction;
     use datafusion_expr::ScalarUDF;
     use datatypes::schema::ColumnSchema;
-    use session::context::QueryContext;
     use store_api::metadata::{ColumnMetadata, RegionMetadataBuilder};
     use store_api::storage::RegionId;
 
@@ -317,19 +318,17 @@ mod tests {
     }
 
     fn matches_func() -> Arc<ScalarUDF> {
-        Arc::new(create_udf(
-            FUNCTION_REGISTRY.get_function("matches").unwrap(),
-            QueryContext::arc(),
-            Default::default(),
-        ))
+        Arc::new(
+            ScalarFunctionFactory::from(Arc::new(MatchesFunction) as FunctionRef)
+                .provide(Default::default()),
+        )
     }
 
     fn matches_term_func() -> Arc<ScalarUDF> {
-        Arc::new(create_udf(
-            FUNCTION_REGISTRY.get_function("matches_term").unwrap(),
-            QueryContext::arc(),
-            Default::default(),
-        ))
+        Arc::new(
+            ScalarFunctionFactory::from(Arc::new(MatchesTermFunction) as FunctionRef)
+                .provide(Default::default()),
+        )
     }
 
     #[test]

src/query/src/datafusion.rs

@@ -25,8 +25,7 @@ use async_trait::async_trait;
 use common_base::Plugins;
 use common_catalog::consts::is_readonly_schema;
 use common_error::ext::BoxedError;
-use common_function::function::FunctionRef;
-use common_function::scalars::aggregate::AggregateFunctionMetaRef;
+use common_function::function_factory::ScalarFunctionFactory;
 use common_query::{Output, OutputData, OutputMeta};
 use common_recordbatch::adapter::RecordBatchStreamAdapter;
 use common_recordbatch::{EmptyRecordBatchStream, SendableRecordBatchStream};
@@ -35,7 +34,9 @@ use datafusion::physical_plan::analyze::AnalyzeExec;
 use datafusion::physical_plan::coalesce_partitions::CoalescePartitionsExec;
 use datafusion::physical_plan::ExecutionPlan;
 use datafusion_common::ResolvedTableReference;
-use datafusion_expr::{DmlStatement, LogicalPlan as DfLogicalPlan, LogicalPlan, WriteOp};
+use datafusion_expr::{
+    AggregateUDF, DmlStatement, LogicalPlan as DfLogicalPlan, LogicalPlan, WriteOp,
+};
 use datatypes::prelude::VectorRef;
 use datatypes::schema::Schema;
 use futures_util::StreamExt;
@@ -454,14 +455,14 @@ impl QueryEngine for DatafusionQueryEngine {
     /// `SELECT "my_UDAF"(x)` will look for an aggregate named `"my_UDAF"`
     ///
     /// So it's better to make UDAF name lowercase when creating one.
-    fn register_aggregate_function(&self, func: AggregateFunctionMetaRef) {
-        self.state.register_aggregate_function(func);
+    fn register_aggregate_function(&self, func: AggregateUDF) {
+        self.state.register_aggr_function(func);
     }
 
-    /// Register an UDF function.
+    /// Register an scalar function.
     /// Will override if the function with same name is already registered.
-    fn register_function(&self, func: FunctionRef) {
-        self.state.register_function(func);
+    fn register_scalar_function(&self, func: ScalarFunctionFactory) {
+        self.state.register_scalar_function(func);
     }
 
     fn read_table(&self, table: TableRef) -> Result<DataFrame> {

src/query/src/datafusion/planner.rs

@@ -18,12 +18,7 @@ use std::sync::Arc;
 
 use arrow_schema::DataType;
 use catalog::table_source::DfTableSourceProvider;
-use common_function::aggr::{
-    GeoPathAccumulator, HllState, UddSketchState, GEO_PATH_NAME, HLL_MERGE_NAME, HLL_NAME,
-    UDDSKETCH_MERGE_NAME, UDDSKETCH_STATE_NAME,
-};
-use common_function::scalars::udf::create_udf;
-use common_query::logical_plan::create_aggregate_function;
+use common_function::function::FunctionContext;
 use datafusion::common::TableReference;
 use datafusion::datasource::cte_worktable::CteWorkTable;
 use datafusion::datasource::file_format::{format_as_file_type, FileFormatFactory};
@@ -151,38 +146,21 @@ impl ContextProvider for DfContextProviderAdapter {
     }
 
     fn get_function_meta(&self, name: &str) -> Option<Arc<ScalarUDF>> {
-        self.engine_state.udf_function(name).map_or_else(
+        self.engine_state.scalar_function(name).map_or_else(
             || self.session_state.scalar_functions().get(name).cloned(),
             |func| {
-                Some(Arc::new(create_udf(
-                    func,
-                    self.query_ctx.clone(),
-                    self.engine_state.function_state(),
-                )))
+                Some(Arc::new(func.provide(FunctionContext {
+                    query_ctx: self.query_ctx.clone(),
+                    state: self.engine_state.function_state(),
+                })))
             },
         )
     }
 
     fn get_aggregate_meta(&self, name: &str) -> Option<Arc<AggregateUDF>> {
-        if name == UDDSKETCH_STATE_NAME {
-            return Some(Arc::new(UddSketchState::state_udf_impl()));
-        } else if name == UDDSKETCH_MERGE_NAME {
-            return Some(Arc::new(UddSketchState::merge_udf_impl()));
-        } else if name == HLL_NAME {
-            return Some(Arc::new(HllState::state_udf_impl()));
-        } else if name == HLL_MERGE_NAME {
-            return Some(Arc::new(HllState::merge_udf_impl()));
-        } else if name == GEO_PATH_NAME {
-            return Some(Arc::new(GeoPathAccumulator::udf_impl()));
-        }
-
-        self.engine_state.aggregate_function(name).map_or_else(
+        self.engine_state.aggr_function(name).map_or_else(
             || self.session_state.aggregate_functions().get(name).cloned(),
-            |func| {
-                Some(Arc::new(
-                    create_aggregate_function(func.name(), func.args_count(), func.create()).into(),
-                ))
-            },
+            |func| Some(Arc::new(func)),
         )
     }
 
@@ -213,13 +191,13 @@ impl ContextProvider for DfContextProviderAdapter {
     }
 
     fn udf_names(&self) -> Vec<String> {
-        let mut names = self.engine_state.udf_names();
+        let mut names = self.engine_state.scalar_names();
         names.extend(self.session_state.scalar_functions().keys().cloned());
         names
     }
 
     fn udaf_names(&self) -> Vec<String> {
-        let mut names = self.engine_state.udaf_names();
+        let mut names = self.engine_state.aggr_names();
         names.extend(self.session_state.aggregate_functions().keys().cloned());
         names
     }

src/query/src/query_engine.rs

@@ -22,14 +22,13 @@ use std::sync::Arc;
 use async_trait::async_trait;
 use catalog::CatalogManagerRef;
 use common_base::Plugins;
-use common_function::function::FunctionRef;
+use common_function::function_factory::ScalarFunctionFactory;
 use common_function::function_registry::FUNCTION_REGISTRY;
 use common_function::handlers::{
     FlowServiceHandlerRef, ProcedureServiceHandlerRef, TableMutationHandlerRef,
 };
-use common_function::scalars::aggregate::AggregateFunctionMetaRef;
 use common_query::Output;
-use datafusion_expr::LogicalPlan;
+use datafusion_expr::{AggregateUDF, LogicalPlan};
 use datatypes::schema::Schema;
 pub use default_serializer::{DefaultPlanDecoder, DefaultSerializer};
 use session::context::QueryContextRef;
@@ -79,11 +78,11 @@ pub trait QueryEngine: Send + Sync {
     ///
     /// # Panics
     /// Will panic if the function with same name is already registered.
-    fn register_aggregate_function(&self, func: AggregateFunctionMetaRef);
+    fn register_aggregate_function(&self, func: AggregateUDF);
 
-    /// Register a SQL function.
+    /// Register a scalar function.
     /// Will override if the function with same name is already registered.
-    fn register_function(&self, func: FunctionRef);
+    fn register_scalar_function(&self, func: ScalarFunctionFactory);
 
     /// Create a DataFrame from a table.
     fn read_table(&self, table: TableRef) -> Result<DataFrame>;
@@ -154,8 +153,8 @@ impl QueryEngineFactory {
 
 /// Register all functions implemented by GreptimeDB
 fn register_functions(query_engine: &Arc<DatafusionQueryEngine>) {
-    for func in FUNCTION_REGISTRY.functions() {
-        query_engine.register_function(func);
+    for func in FUNCTION_REGISTRY.scalar_functions() {
+        query_engine.register_scalar_function(func);
     }
 
     for accumulator in FUNCTION_REGISTRY.aggregate_functions() {

src/query/src/query_engine/default_serializer.rs

@@ -15,9 +15,8 @@
 use std::sync::Arc;
 
 use common_error::ext::BoxedError;
-use common_function::aggr::{GeoPathAccumulator, HllState, UddSketchState};
+use common_function::function::FunctionContext;
 use common_function::function_registry::FUNCTION_REGISTRY;
-use common_function::scalars::udf::create_udf;
 use common_query::error::RegisterUdfSnafu;
 use common_query::logical_plan::SubstraitPlanDecoder;
 use datafusion::catalog::CatalogProviderList;
@@ -124,43 +123,46 @@ impl SubstraitPlanDecoder for DefaultPlanDecoder {
         // if they have the same name as the default UDFs or their alias.
         // e.g. The default UDF `to_char()` has an alias `date_format()`, if we register a UDF with the name `date_format()`
         // before we build the session state, the UDF will be lost.
-        for func in FUNCTION_REGISTRY.functions() {
-            let udf = Arc::new(create_udf(
-                func.clone(),
-                self.query_ctx.clone(),
-                Default::default(),
-            ));
+        for func in FUNCTION_REGISTRY.scalar_functions() {
+            let udf = func.provide(FunctionContext {
+                query_ctx: self.query_ctx.clone(),
+                state: Default::default(),
+            });
             session_state
-                .register_udf(udf)
+                .register_udf(Arc::new(udf))
                 .context(RegisterUdfSnafu { name: func.name() })?;
-            let _ = session_state.register_udaf(Arc::new(UddSketchState::state_udf_impl()));
-            let _ = session_state.register_udaf(Arc::new(UddSketchState::merge_udf_impl()));
-            let _ = session_state.register_udaf(Arc::new(HllState::state_udf_impl()));
-            let _ = session_state.register_udaf(Arc::new(HllState::merge_udf_impl()));
-            let _ = session_state.register_udaf(Arc::new(GeoPathAccumulator::udf_impl()));
-            let _ = session_state.register_udaf(quantile_udaf());
-
-            let _ = session_state.register_udf(Arc::new(IDelta::<false>::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(IDelta::<true>::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(Rate::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(Increase::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(Delta::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(Resets::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(Changes::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(Deriv::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(Round::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(AvgOverTime::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(MinOverTime::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(MaxOverTime::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(SumOverTime::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(CountOverTime::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(LastOverTime::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(AbsentOverTime::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(PresentOverTime::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(StddevOverTime::scalar_udf()));
-            let _ = session_state.register_udf(Arc::new(StdvarOverTime::scalar_udf()));
-            // TODO(ruihang): add quantile_over_time, predict_linear, holt_winters, round
         }
+
+        for func in FUNCTION_REGISTRY.aggregate_functions() {
+            let name = func.name().to_string();
+            session_state
+                .register_udaf(Arc::new(func))
+                .context(RegisterUdfSnafu { name })?;
+        }
+
+        let _ = session_state.register_udaf(quantile_udaf());
+
+        let _ = session_state.register_udf(Arc::new(IDelta::<false>::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(IDelta::<true>::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(Rate::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(Increase::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(Delta::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(Resets::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(Changes::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(Deriv::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(Round::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(AvgOverTime::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(MinOverTime::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(MaxOverTime::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(SumOverTime::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(CountOverTime::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(LastOverTime::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(AbsentOverTime::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(PresentOverTime::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(StddevOverTime::scalar_udf()));
+        let _ = session_state.register_udf(Arc::new(StdvarOverTime::scalar_udf()));
+        // TODO(ruihang): add quantile_over_time, predict_linear, holt_winters, round
+
         let logical_plan = DFLogicalSubstraitConvertor
             .decode(message, session_state)
             .await

src/query/src/query_engine/state.rs

@@ -19,11 +19,10 @@ use std::sync::{Arc, RwLock};
 use async_trait::async_trait;
 use catalog::CatalogManagerRef;
 use common_base::Plugins;
-use common_function::function::FunctionRef;
+use common_function::function_factory::ScalarFunctionFactory;
 use common_function::handlers::{
     FlowServiceHandlerRef, ProcedureServiceHandlerRef, TableMutationHandlerRef,
 };
-use common_function::scalars::aggregate::AggregateFunctionMetaRef;
 use common_function::state::FunctionState;
 use common_telemetry::warn;
 use datafusion::dataframe::DataFrame;
@@ -37,7 +36,7 @@ use datafusion::physical_optimizer::sanity_checker::SanityCheckPlan;
 use datafusion::physical_optimizer::PhysicalOptimizerRule;
 use datafusion::physical_plan::ExecutionPlan;
 use datafusion::physical_planner::{DefaultPhysicalPlanner, ExtensionPlanner, PhysicalPlanner};
-use datafusion_expr::LogicalPlan as DfLogicalPlan;
+use datafusion_expr::{AggregateUDF, LogicalPlan as DfLogicalPlan};
 use datafusion_optimizer::analyzer::count_wildcard_rule::CountWildcardRule;
 use datafusion_optimizer::analyzer::{Analyzer, AnalyzerRule};
 use datafusion_optimizer::optimizer::Optimizer;
@@ -70,8 +69,8 @@ pub struct QueryEngineState {
     df_context: SessionContext,
     catalog_manager: CatalogManagerRef,
     function_state: Arc<FunctionState>,
-    udf_functions: Arc<RwLock<HashMap<String, FunctionRef>>>,
-    aggregate_functions: Arc<RwLock<HashMap<String, AggregateFunctionMetaRef>>>,
+    scalar_functions: Arc<RwLock<HashMap<String, ScalarFunctionFactory>>>,
+    aggr_functions: Arc<RwLock<HashMap<String, AggregateUDF>>>,
     extension_rules: Vec<Arc<dyn ExtensionAnalyzerRule + Send + Sync>>,
     plugins: Plugins,
 }
@@ -186,10 +185,10 @@ impl QueryEngineState {
                 procedure_service_handler,
                 flow_service_handler,
             }),
-            aggregate_functions: Arc::new(RwLock::new(HashMap::new())),
+            aggr_functions: Arc::new(RwLock::new(HashMap::new())),
             extension_rules,
             plugins,
-            udf_functions: Arc::new(RwLock::new(HashMap::new())),
+            scalar_functions: Arc::new(RwLock::new(HashMap::new())),
         }
     }
 
@@ -222,38 +221,28 @@ impl QueryEngineState {
         self.session_state().optimize(&plan)
     }
 
-    /// Register an udf function.
-    /// Will override if the function with same name is already registered.
-    pub fn register_function(&self, func: FunctionRef) {
-        let name = func.name().to_string();
-        let x = self
-            .udf_functions
-            .write()
-            .unwrap()
-            .insert(name.clone(), func);
-
-        if x.is_some() {
-            warn!("Already registered udf function '{name}'");
-        }
-    }
-
-    /// Retrieve the udf function by name
-    pub fn udf_function(&self, function_name: &str) -> Option<FunctionRef> {
-        self.udf_functions
+    /// Retrieve the scalar function by name
+    pub fn scalar_function(&self, function_name: &str) -> Option<ScalarFunctionFactory> {
+        self.scalar_functions
             .read()
             .unwrap()
             .get(function_name)
             .cloned()
     }
 
-    /// Retrieve udf function names.
-    pub fn udf_names(&self) -> Vec<String> {
-        self.udf_functions.read().unwrap().keys().cloned().collect()
+    /// Retrieve scalar function names.
+    pub fn scalar_names(&self) -> Vec<String> {
+        self.scalar_functions
+            .read()
+            .unwrap()
+            .keys()
+            .cloned()
+            .collect()
     }
 
     /// Retrieve the aggregate function by name
-    pub fn aggregate_function(&self, function_name: &str) -> Option<AggregateFunctionMetaRef> {
-        self.aggregate_functions
+    pub fn aggr_function(&self, function_name: &str) -> Option<AggregateUDF> {
+        self.aggr_functions
             .read()
             .unwrap()
             .get(function_name)
@@ -261,8 +250,8 @@ impl QueryEngineState {
     }
 
     /// Retrieve aggregate function names.
-    pub fn udaf_names(&self) -> Vec<String> {
-        self.aggregate_functions
+    pub fn aggr_names(&self) -> Vec<String> {
+        self.aggr_functions
             .read()
             .unwrap()
             .keys()
@@ -270,6 +259,21 @@ impl QueryEngineState {
             .collect()
     }
 
+    /// Register an scalar function.
+    /// Will override if the function with same name is already registered.
+    pub fn register_scalar_function(&self, func: ScalarFunctionFactory) {
+        let name = func.name().to_string();
+        let x = self
+            .scalar_functions
+            .write()
+            .unwrap()
+            .insert(name.clone(), func);
+
+        if x.is_some() {
+            warn!("Already registered scalar function '{name}'");
+        }
+    }
+
     /// Register an aggregate function.
     ///
     /// # Panics
@@ -278,10 +282,10 @@ impl QueryEngineState {
     /// Panicking consideration: currently the aggregated functions are all statically registered,
     /// user cannot define their own aggregate functions on the fly. So we can panic here. If that
     /// invariant is broken in the future, we should return an error instead of panicking.
-    pub fn register_aggregate_function(&self, func: AggregateFunctionMetaRef) {
-        let name = func.name();
+    pub fn register_aggr_function(&self, func: AggregateUDF) {
+        let name = func.name().to_string();
         let x = self
-            .aggregate_functions
+            .aggr_functions
             .write()
             .unwrap()
             .insert(name.clone(), func);

src/query/src/tests/my_sum_udaf_example.rs

@@ -16,11 +16,12 @@ use std::fmt::Debug;
 use std::marker::PhantomData;
 use std::sync::Arc;
 
-use common_function::scalars::aggregate::AggregateFunctionMeta;
 use common_macro::{as_aggr_func_creator, AggrFuncTypeStore};
 use common_query::error::{CreateAccumulatorSnafu, Result as QueryResult};
 use common_query::logical_plan::accumulator::AggrFuncTypeStore;
-use common_query::logical_plan::{Accumulator, AggregateFunctionCreator};
+use common_query::logical_plan::{
+    create_aggregate_function, Accumulator, AggregateFunctionCreator,
+};
 use common_query::prelude::*;
 use common_recordbatch::{RecordBatch, RecordBatches};
 use datatypes::prelude::*;
@@ -207,11 +208,14 @@ where
 
     let engine = new_query_engine_with_table(testing_table);
 
-    engine.register_aggregate_function(Arc::new(AggregateFunctionMeta::new(
-        "my_sum",
-        1,
-        Arc::new(|| Arc::new(MySumAccumulatorCreator::default())),
-    )));
+    engine.register_aggregate_function(
+        create_aggregate_function(
+            "my_sum".to_string(),
+            1,
+            Arc::new(MySumAccumulatorCreator::default()),
+        )
+        .into(),
+    );
 
     let sql = format!("select MY_SUM({column_name}) as my_sum from {table_name}");
     let batches = exec_selection(engine, &sql).await;