ClickHouse

1
#include <AggregateFunctions/AggregateFunctionQuantile.h>
2
#include <AggregateFunctions/QuantileDD.h>
3
#include <AggregateFunctions/AggregateFunctionFactory.h>
4
#include <AggregateFunctions/Helpers.h>
5
#include <DataTypes/DataTypeDate.h>
6
#include <DataTypes/DataTypeDateTime.h>
7
#include <Core/Field.h>
8

9

10
namespace DB
11
{
12
struct Settings;
13

14
namespace ErrorCodes
15
{
16
    extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
17
    extern const int ILLEGAL_TYPE_OF_ARGUMENT;
18
}
19

20
namespace
21
{
22

23
template <typename Value, bool float_return> using FuncQuantileDD = AggregateFunctionQuantile<Value, QuantileDD<Value>, NameQuantileDD, false, std::conditional_t<float_return, Float64, void>, false, true>;
24
template <typename Value, bool float_return> using FuncQuantilesDD = AggregateFunctionQuantile<Value, QuantileDD<Value>, NameQuantilesDD, false, std::conditional_t<float_return, Float64, void>, true, true>;
25

26

27
template <template <typename, bool> class Function>
28
AggregateFunctionPtr createAggregateFunctionQuantile(
29
    const std::string & name, const DataTypes & argument_types, const Array & params, const Settings *)
30
{
31
    if (argument_types.empty())
32
        throw Exception(ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH, "Aggregate function {} requires at least one argument", name);
33

34
    const DataTypePtr & argument_type = argument_types[0];
35
    WhichDataType which(argument_type);
36

37
#define DISPATCH(TYPE) \
38
    if (which.idx == TypeIndex::TYPE) return std::make_shared<Function<TYPE, true>>(argument_types, params);
39
    FOR_BASIC_NUMERIC_TYPES(DISPATCH)
40
#undef DISPATCH
41
    if (which.idx == TypeIndex::Date) return std::make_shared<Function<DataTypeDate::FieldType, false>>(argument_types, params);
42
    if (which.idx == TypeIndex::DateTime) return std::make_shared<Function<DataTypeDateTime::FieldType, false>>(argument_types, params);
43

44
    throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Illegal type {} of argument for aggregate function {}",
45
                    argument_type->getName(), name);
46
}
47

48
}
49

50
void registerAggregateFunctionsQuantileDD(AggregateFunctionFactory & factory)
51
{
52
    /// For aggregate functions returning array we cannot return NULL on empty set.
53
    AggregateFunctionProperties properties = { .returns_default_when_only_null = true };
54

55
    factory.registerFunction(NameQuantileDD::name, createAggregateFunctionQuantile<FuncQuantileDD>);
56
    factory.registerFunction(NameQuantilesDD::name, { createAggregateFunctionQuantile<FuncQuantilesDD>, properties });
57

58
    /// 'median' is an alias for 'quantile'
59
    factory.registerAlias("medianDD", NameQuantileDD::name);
60
}
61

62
}
63