ClickHouse

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#include <AggregateFunctions/AggregateFunctionQuantile.h>
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#include <AggregateFunctions/QuantileTDigest.h>
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#include <AggregateFunctions/AggregateFunctionFactory.h>
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#include <AggregateFunctions/Helpers.h>
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#include <DataTypes/DataTypeDate.h>
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#include <DataTypes/DataTypeDateTime.h>
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#include <Core/Field.h>
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namespace DB
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{
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struct Settings;
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namespace ErrorCodes
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{
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    extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
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    extern const int ILLEGAL_TYPE_OF_ARGUMENT;
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}
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namespace
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{
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template <typename Value, bool float_return> using FuncQuantileTDigestWeighted = AggregateFunctionQuantile<Value, QuantileTDigest<Value>, NameQuantileTDigestWeighted, true, std::conditional_t<float_return, Float32, void>, false, false>;
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template <typename Value, bool float_return> using FuncQuantilesTDigestWeighted = AggregateFunctionQuantile<Value, QuantileTDigest<Value>, NameQuantilesTDigestWeighted, true, std::conditional_t<float_return, Float32, void>, true, false>;
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template <template <typename, bool> class Function>
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AggregateFunctionPtr createAggregateFunctionQuantile(
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    const std::string & name, const DataTypes & argument_types, const Array & params, const Settings *)
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{
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    if (argument_types.empty())
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        throw Exception(ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH, "Aggregate function {} requires at least one argument", name);
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    const DataTypePtr & argument_type = argument_types[0];
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    WhichDataType which(argument_type);
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#define DISPATCH(TYPE) \
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    if (which.idx == TypeIndex::TYPE) return std::make_shared<Function<TYPE, true>>(argument_types, params);
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    FOR_BASIC_NUMERIC_TYPES(DISPATCH)
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#undef DISPATCH
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    if (which.idx == TypeIndex::Date) return std::make_shared<Function<DataTypeDate::FieldType, false>>(argument_types, params);
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    if (which.idx == TypeIndex::DateTime) return std::make_shared<Function<DataTypeDateTime::FieldType, false>>(argument_types, params);
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    throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Illegal type {} of argument for aggregate function {}",
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                    argument_type->getName(), name);
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}
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}
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void registerAggregateFunctionsQuantileTDigestWeighted(AggregateFunctionFactory & factory)
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{
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    /// For aggregate functions returning array we cannot return NULL on empty set.
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    AggregateFunctionProperties properties = { .returns_default_when_only_null = true };
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    factory.registerFunction(NameQuantileTDigestWeighted::name, createAggregateFunctionQuantile<FuncQuantileTDigestWeighted>);
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    factory.registerFunction(NameQuantilesTDigestWeighted::name, { createAggregateFunctionQuantile<FuncQuantilesTDigestWeighted>, properties });
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    /// 'median' is an alias for 'quantile'
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    factory.registerAlias("medianTDigestWeighted", NameQuantileTDigestWeighted::name);
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}
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}
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