Reformat aggregate functions (duckdb#14530)

### Merge order
The function formatting PRs should be merged in this order (all pointing
to Feature branch):
- [14470 - Reformat compressed materialization
functions](duckdb#14470)
- [14489 - Reformat arithmetic
operators](duckdb#14489)
- [14495 - Reformat nested and sequence
functions](duckdb#14495)
- [14530 - Reformat aggregate
functions](duckdb#14530) (this PR)

scripts/generate_functions.py

@@ -4,7 +4,7 @@
 
 
 function_groups = {
-    ('src', 'include/duckdb', 'function'): ['scalar'],
+    ('src', 'include/duckdb', 'function'): ['scalar', 'aggregate'],
     ('extension', 'core_functions/include', 'core_functions'): ['scalar', 'aggregate'],
 }
 

src/execution/operator/join/physical_hash_join.cpp

@@ -4,6 +4,7 @@
 #include "duckdb/execution/expression_executor.hpp"
 #include "duckdb/execution/operator/aggregate/ungrouped_aggregate_state.hpp"
 #include "duckdb/function/aggregate/distributive_functions.hpp"
+#include "duckdb/function/aggregate/distributive_function_utils.hpp"
 #include "duckdb/function/function_binder.hpp"
 #include "duckdb/main/client_context.hpp"
 #include "duckdb/main/query_profiler.hpp"
@@ -248,7 +249,7 @@ unique_ptr<JoinHashTable> PhysicalHashJoin::InitializeHashTable(ClientContext &c
 			delim_payload_types.push_back(aggr->return_type);
 			info.correlated_aggregates.push_back(std::move(aggr));
 
-			auto count_fun = CountFun::GetFunction();
+			auto count_fun = CountFunctionBase::GetFunction();
 			vector<unique_ptr<Expression>> children;
 			// this is a dummy but we need it to make the hash table understand whats going on
 			children.push_back(make_uniq_base<Expression, BoundReferenceExpression>(count_fun.return_type, 0U));

src/execution/physical_plan/plan_distinct.cpp

@@ -1,7 +1,7 @@
 #include "duckdb/execution/operator/aggregate/physical_hash_aggregate.hpp"
 #include "duckdb/execution/operator/projection/physical_projection.hpp"
 #include "duckdb/execution/physical_plan_generator.hpp"
-#include "duckdb/function/aggregate/distributive_functions.hpp"
+#include "duckdb/function/aggregate/distributive_function_utils.hpp"
 #include "duckdb/planner/expression/bound_aggregate_expression.hpp"
 #include "duckdb/planner/expression/bound_reference_expression.hpp"
 #include "duckdb/planner/operator/logical_distinct.hpp"
@@ -59,8 +59,9 @@ unique_ptr<PhysicalOperator> PhysicalPlanGenerator::CreatePlan(LogicalDistinct &
 			first_children.push_back(std::move(bound));
 
 			FunctionBinder function_binder(context);
-			auto first_aggregate = function_binder.BindAggregateFunction(
-			    FirstFun::GetFunction(logical_type), std::move(first_children), nullptr, AggregateType::NON_DISTINCT);
+			auto first_aggregate =
+			    function_binder.BindAggregateFunction(FirstFunctionGetter::GetFunction(logical_type),
+			                                          std::move(first_children), nullptr, AggregateType::NON_DISTINCT);
 			first_aggregate->order_bys = op.order_by ? op.order_by->Copy() : nullptr;
 
 			if (ClientConfig::GetConfig(context).enable_optimizer) {

src/function/aggregate/CMakeLists.txt

@@ -1,7 +1,6 @@
 add_subdirectory(distributive)
 
-add_library_unity(duckdb_func_aggr OBJECT distributive_functions.cpp
-                  sorted_aggregate_function.cpp)
+add_library_unity(duckdb_func_aggr OBJECT sorted_aggregate_function.cpp)
 set(ALL_OBJECT_FILES
     ${ALL_OBJECT_FILES} $<TARGET_OBJECTS:duckdb_func_aggr>
     PARENT_SCOPE)

src/function/aggregate/distributive/CMakeLists.txt

@@ -1,4 +1,5 @@
-add_library_unity(duckdb_aggr_distr OBJECT count.cpp first.cpp minmax.cpp)
+add_library_unity(duckdb_aggr_distr OBJECT count.cpp first_last_any.cpp
+                  minmax.cpp)
 set(ALL_OBJECT_FILES
     ${ALL_OBJECT_FILES} $<TARGET_OBJECTS:duckdb_aggr_distr>
     PARENT_SCOPE)

src/function/aggregate/distributive/count.cpp

@@ -1,6 +1,7 @@
 #include "duckdb/common/exception.hpp"
 #include "duckdb/common/vector_operations/vector_operations.hpp"
 #include "duckdb/function/aggregate/distributive_functions.hpp"
+#include "duckdb/function/aggregate/distributive_function_utils.hpp"
 #include "duckdb/planner/expression/bound_aggregate_expression.hpp"
 
 namespace duckdb {
@@ -210,7 +211,7 @@ struct CountFunction : public BaseCountFunction {
 	}
 };
 
-AggregateFunction CountFun::GetFunction() {
+AggregateFunction CountFunctionBase::GetFunction() {
 	AggregateFunction fun({LogicalType(LogicalTypeId::ANY)}, LogicalType::BIGINT, AggregateFunction::StateSize<int64_t>,
 	                      AggregateFunction::StateInitialize<int64_t, CountFunction>, CountFunction::CountScatter,
 	                      AggregateFunction::StateCombine<int64_t, CountFunction>,
@@ -241,21 +242,14 @@ unique_ptr<BaseStatistics> CountPropagateStats(ClientContext &context, BoundAggr
 	return nullptr;
 }
 
-void CountFun::RegisterFunction(BuiltinFunctions &set) {
-	AggregateFunction count_function = CountFun::GetFunction();
+AggregateFunctionSet CountFun::GetFunctions() {
+	AggregateFunction count_function = CountFunctionBase::GetFunction();
 	count_function.statistics = CountPropagateStats;
 	AggregateFunctionSet count("count");
 	count.AddFunction(count_function);
 	// the count function can also be called without arguments
-	count_function = CountStarFun::GetFunction();
-	count.AddFunction(count_function);
-	set.AddFunction(count);
-}
-
-void CountStarFun::RegisterFunction(BuiltinFunctions &set) {
-	AggregateFunctionSet count("count_star");
 	count.AddFunction(CountStarFun::GetFunction());
-	set.AddFunction(count);
+	return count;
 }
 
 } // namespace duckdb

src/function/aggregate/distributive/first.cpp → src/function/aggregate/distributive/first_last_any.cpp

@@ -1,6 +1,7 @@
 #include "duckdb/common/exception.hpp"
 #include "duckdb/common/vector_operations/vector_operations.hpp"
 #include "duckdb/function/aggregate/distributive_functions.hpp"
+#include "duckdb/function/aggregate/distributive_function_utils.hpp"
 #include "duckdb/function/create_sort_key.hpp"
 #include "duckdb/planner/expression.hpp"
 
@@ -293,7 +294,7 @@ static AggregateFunction GetFirstFunction(const LogicalType &type) {
 	}
 }
 
-AggregateFunction FirstFun::GetFunction(const LogicalType &type) {
+AggregateFunction FirstFunctionGetter::GetFunction(const LogicalType &type) {
 	auto fun = GetFirstFunction<false, false>(type);
 	fun.name = "first";
 	return fun;
@@ -340,22 +341,22 @@ static void AddFirstOperator(AggregateFunctionSet &set) {
 	                                  nullptr, BindFirst<LAST, SKIP_NULLS>));
 }
 
-void FirstFun::RegisterFunction(BuiltinFunctions &set) {
+AggregateFunctionSet FirstFun::GetFunctions() {
 	AggregateFunctionSet first("first");
-	AggregateFunctionSet last("last");
-	AggregateFunctionSet any_value("any_value");
-
 	AddFirstOperator<false, false>(first);
-	AddFirstOperator<true, false>(last);
-	AddFirstOperator<false, true>(any_value);
-
-	set.AddFunction(first);
-	first.name = "arbitrary";
-	set.AddFunction(first);
+	return first;
+}
 
-	set.AddFunction(last);
+AggregateFunctionSet LastFun::GetFunctions() {
+	AggregateFunctionSet last("last");
+	AddFirstOperator<true, false>(last);
+	return last;
+}
 
-	set.AddFunction(any_value);
+AggregateFunctionSet AnyValueFun::GetFunctions() {
+	AggregateFunctionSet any_value("any_value");
+	AddFirstOperator<false, true>(any_value);
+	return any_value;
 }
 
 } // namespace duckdb

src/function/aggregate/distributive/functions.json

@@ -0,0 +1,52 @@
+[
+    {
+        "name": "count_star",
+        "parameters": "",
+        "description": "",
+        "example": "",
+        "type": "aggregate_function"
+    },
+    {
+        "name": "count",
+        "parameters": "arg",
+        "description": "Returns the number of non-null values in arg.",
+        "example": "count(A)",
+        "type": "aggregate_function_set"
+    },
+    {
+        "name": "first",
+        "parameters": "arg",
+        "description": "Returns the first value (null or non-null) from arg. This function is affected by ordering.",
+        "example": "first(A)",
+        "type": "aggregate_function_set",
+        "aliases": ["arbitrary"]
+    },
+    {
+        "name": "last",
+        "parameters": "arg",
+        "description": "Returns the last value of a column. This function is affected by ordering.",
+        "example": "last(A)",
+        "type": "aggregate_function_set"
+    },
+    {
+        "name": "any_value",
+        "parameters": "arg",
+        "description": "Returns the first non-null value from arg. This function is affected by ordering.",
+        "example": "",
+        "type": "aggregate_function_set"
+    },
+    {
+        "name": "min",
+        "parameters": "arg",
+        "description": "Returns the minimum value present in arg.",
+        "example": "min(A)",
+        "type": "aggregate_function_set"
+    },
+    {
+        "name": "max",
+        "parameters": "arg",
+        "description": "Returns the maximum value present in arg.",
+        "example": "max(A)",
+        "type": "aggregate_function_set"
+    }
+]

src/function/aggregate/distributive/minmax.cpp

@@ -4,6 +4,7 @@
 #include "duckdb/common/types/null_value.hpp"
 #include "duckdb/common/vector_operations/vector_operations.hpp"
 #include "duckdb/function/aggregate/distributive_functions.hpp"
+#include "duckdb/function/aggregate/distributive_function_utils.hpp"
 #include "duckdb/function/aggregate/minmax_n_helpers.hpp"
 #include "duckdb/function/aggregate/sort_key_helpers.hpp"
 #include "duckdb/function/function_binder.hpp"
@@ -389,11 +390,11 @@ static AggregateFunction GetMinMaxOperator(string name) {
 	                         nullptr, nullptr, BindMinMax<OP, OP_STRING, OP_VECTOR>);
 }
 
-AggregateFunction MinFun::GetFunction() {
+AggregateFunction MinFunction::GetFunction() {
 	return GetMinMaxOperator<MinOperation, MinOperationString, MinOperationVector>("min");
 }
 
-AggregateFunction MaxFun::GetFunction() {
+AggregateFunction MaxFunction::GetFunction() {
 	return GetMinMaxOperator<MaxOperation, MaxOperationString, MaxOperationVector>("max");
 }
 
@@ -537,18 +538,18 @@ static AggregateFunction GetMinMaxNFunction() {
 //---------------------------------------------------
 // Function Registration
 //---------------------------------------------------s
-void MinFun::RegisterFunction(BuiltinFunctions &set) {
+AggregateFunctionSet MinFun::GetFunctions() {
 	AggregateFunctionSet min("min");
-	min.AddFunction(GetFunction());
+	min.AddFunction(MinFunction::GetFunction());
 	min.AddFunction(GetMinMaxNFunction<LessThan>());
-	set.AddFunction(min);
+	return min;
 }
 
-void MaxFun::RegisterFunction(BuiltinFunctions &set) {
+AggregateFunctionSet MaxFun::GetFunctions() {
 	AggregateFunctionSet max("max");
-	max.AddFunction(GetFunction());
+	max.AddFunction(MaxFunction::GetFunction());
 	max.AddFunction(GetMinMaxNFunction<GreaterThan>());
-	set.AddFunction(max);
+	return max;
 }
 
 } // namespace duckdb

src/function/function.cpp

@@ -94,8 +94,6 @@ void BuiltinFunctions::Initialize() {
 	RegisterTableFunctions();
 	RegisterArrowFunctions();
 
-	RegisterDistributiveAggregates();
-
 	RegisterPragmaFunctions();
 
 	// initialize collations

src/function/function_list.cpp

@@ -1,4 +1,6 @@
 #include "duckdb/function/function_list.hpp"
+
+#include "duckdb/function/aggregate/distributive_functions.hpp"
 #include "duckdb/function/scalar/compressed_materialization_functions.hpp"
 #include "duckdb/function/scalar/date_functions.hpp"
 #include "duckdb/function/scalar/generic_functions.hpp"
@@ -66,6 +68,8 @@ static const StaticFunctionDefinition function[] = {
 	DUCKDB_SCALAR_FUNCTION_SET(InternalDecompressIntegralUsmallintFun),
 	DUCKDB_SCALAR_FUNCTION_SET(InternalDecompressStringFun),
 	DUCKDB_SCALAR_FUNCTION_SET_ALIAS(AddFun),
+	DUCKDB_AGGREGATE_FUNCTION_SET(AnyValueFun),
+	DUCKDB_AGGREGATE_FUNCTION_SET_ALIAS(ArbitraryFun),
 	DUCKDB_SCALAR_FUNCTION_ALIAS(ArrayCatFun),
 	DUCKDB_SCALAR_FUNCTION_ALIAS(ArrayConcatFun),
 	DUCKDB_SCALAR_FUNCTION_ALIAS(ArrayContainsFun),
@@ -84,13 +88,17 @@ static const StaticFunctionDefinition function[] = {
 	DUCKDB_SCALAR_FUNCTION(ConcatWsFun),
 	DUCKDB_SCALAR_FUNCTION(ConstantOrNullFun),
 	DUCKDB_SCALAR_FUNCTION_SET(ContainsFun),
+	DUCKDB_AGGREGATE_FUNCTION_SET(CountFun),
+	DUCKDB_AGGREGATE_FUNCTION(CountStarFun),
 	DUCKDB_SCALAR_FUNCTION(CreateSortKeyFun),
 	DUCKDB_SCALAR_FUNCTION(CurrvalFun),
 	DUCKDB_SCALAR_FUNCTION_SET_ALIAS(DivideFun),
 	DUCKDB_SCALAR_FUNCTION(ErrorFun),
 	DUCKDB_SCALAR_FUNCTION(FinalizeFun),
+	DUCKDB_AGGREGATE_FUNCTION_SET(FirstFun),
 	DUCKDB_SCALAR_FUNCTION(GetVariableFun),
 	DUCKDB_SCALAR_FUNCTION(IlikeEscapeFun),
+	DUCKDB_AGGREGATE_FUNCTION_SET(LastFun),
 	DUCKDB_SCALAR_FUNCTION_ALIAS(LcaseFun),
 	DUCKDB_SCALAR_FUNCTION_SET_ALIAS(LenFun),
 	DUCKDB_SCALAR_FUNCTION_SET(LengthFun),
@@ -110,8 +118,10 @@ static const StaticFunctionDefinition function[] = {
 	DUCKDB_SCALAR_FUNCTION(ListZipFun),
 	DUCKDB_SCALAR_FUNCTION(LowerFun),
 	DUCKDB_SCALAR_FUNCTION(MapContainsFun),
+	DUCKDB_AGGREGATE_FUNCTION_SET(MaxFun),
 	DUCKDB_SCALAR_FUNCTION_SET(MD5Fun),
 	DUCKDB_SCALAR_FUNCTION_SET(MD5NumberFun),
+	DUCKDB_AGGREGATE_FUNCTION_SET(MinFun),
 	DUCKDB_SCALAR_FUNCTION_SET_ALIAS(ModFun),
 	DUCKDB_SCALAR_FUNCTION_SET_ALIAS(MultiplyFun),
 	DUCKDB_SCALAR_FUNCTION(NextvalFun),

src/include/duckdb/function/aggregate/distributive_function_utils.hpp

@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//                         DuckDB
+//
+// duckdb/function/aggregate/distributive_functions.hpp
+//
+//
+//===----------------------------------------------------------------------===//
+
+#pragma once
+
+#include "duckdb/function/function_set.hpp"
+
+namespace duckdb {
+
+struct CountFunctionBase {
+	static AggregateFunction GetFunction();
+};
+
+struct FirstFunctionGetter {
+	static AggregateFunction GetFunction(const LogicalType &type);
+};
+
+struct MinFunction {
+	static AggregateFunction GetFunction();
+};
+
+struct MaxFunction {
+	static AggregateFunction GetFunction();
+};
+
+} // namespace duckdb