#include #include #include #include #include #include #include namespace DB { namespace ErrorCodes { extern const int ILLEGAL_TYPE_OF_ARGUMENT; } namespace { class FunctionLowCardinalityIndices: public IFunction { public: static constexpr auto name = "lowCardinalityIndices"; static FunctionPtr create(ContextPtr) { return std::make_shared(); } String getName() const override { return name; } size_t getNumberOfArguments() const override { return 1; } bool useDefaultImplementationForNulls() const override { return false; } bool useDefaultImplementationForConstants() const override { return true; } bool useDefaultImplementationForLowCardinalityColumns() const override { return false; } bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return false; } DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override { const auto * type = typeid_cast(arguments[0].get()); if (!type) throw Exception("First first argument of function lowCardinalityIndexes must be ColumnLowCardinality, but got " + arguments[0]->getName(), ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT); return std::make_shared(); } ColumnPtr executeImpl(const ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t /*input_rows_count*/) const override { const auto & arg = arguments[0]; auto indexes_col = typeid_cast(arg.column.get())->getIndexesPtr(); auto new_indexes_col = ColumnUInt64::create(indexes_col->size()); auto & data = new_indexes_col->getData(); for (size_t i = 0; i < data.size(); ++i) data[i] = indexes_col->getUInt(i); return new_indexes_col; } }; } void registerFunctionLowCardinalityIndices(FunctionFactory & factory) { factory.registerFunction(); } }