ClickHouse

1
#include <AggregateFunctions/AggregateFunctionQuantile.h>
2
#include <AggregateFunctions/QuantileExact.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 _> using FuncQuantileExactLow = AggregateFunctionQuantile<Value, QuantileExactLow<Value>, NameQuantileExactLow, false, void, false, false>;
24
template <typename Value, bool _> using FuncQuantilesExactLow = AggregateFunctionQuantile<Value, QuantileExactLow<Value>, NameQuantilesExactLow, false, void, true, false>;
25

26
template <template <typename, bool> class Function>
27
AggregateFunctionPtr createAggregateFunctionQuantile(
28
    const std::string & name, const DataTypes & argument_types, const Array & params, const Settings *)
29
{
30
    if (argument_types.empty())
31
        throw Exception(ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH, "Aggregate function {} requires at least one argument", name);
32

33
    const DataTypePtr & argument_type = argument_types[0];
34
    WhichDataType which(argument_type);
35

36
#define DISPATCH(TYPE) \
37
    if (which.idx == TypeIndex::TYPE) return std::make_shared<Function<TYPE, true>>(argument_types, params);
38
    FOR_BASIC_NUMERIC_TYPES(DISPATCH)
39
#undef DISPATCH
40
    if (which.idx == TypeIndex::Date) return std::make_shared<Function<DataTypeDate::FieldType, false>>(argument_types, params);
41
    if (which.idx == TypeIndex::DateTime) return std::make_shared<Function<DataTypeDateTime::FieldType, false>>(argument_types, params);
42

43
    if (which.idx == TypeIndex::Decimal32) return std::make_shared<Function<Decimal32, false>>(argument_types, params);
44
    if (which.idx == TypeIndex::Decimal64) return std::make_shared<Function<Decimal64, false>>(argument_types, params);
45
    if (which.idx == TypeIndex::Decimal128) return std::make_shared<Function<Decimal128, false>>(argument_types, params);
46
    if (which.idx == TypeIndex::Decimal256) return std::make_shared<Function<Decimal256, false>>(argument_types, params);
47
    if (which.idx == TypeIndex::DateTime64) return std::make_shared<Function<DateTime64, false>>(argument_types, params);
48

49
    throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Illegal type {} of argument for aggregate function {}",
50
                    argument_type->getName(), name);
51
}
52

53
}
54

55
void registerAggregateFunctionsQuantileExactLow(AggregateFunctionFactory & factory)
56
{
57
    /// For aggregate functions returning array we cannot return NULL on empty set.
58
    AggregateFunctionProperties properties = { .returns_default_when_only_null = true };
59

60
    factory.registerFunction(NameQuantileExactLow::name, createAggregateFunctionQuantile<FuncQuantileExactLow>);
61
    factory.registerFunction(NameQuantilesExactLow::name, { createAggregateFunctionQuantile<FuncQuantilesExactLow>, properties });
62

63
    /// 'median' is an alias for 'quantile'
64
    factory.registerAlias("medianExactLow", NameQuantileExactLow::name);
65
}
66

67
}
68