**Use case**

Workload generation with continuous queries.

**Describe the solution you'd like**

Similar to now() but non-constant.

{
public:
    explicit FunctionBaseNow(time_t time_, DataTypes argument_types_, DataTypePtr return_type_)
        : time_value(time_), argument_types(std::move(argument_types_)), return_type(std::move(return_type_)) {}
    String getName() const override { return "now"; }
    const DataTypes & getArgumentTypes() const override
    {
        return argument_types;
    }
    const DataTypePtr & getResultType() const override
    {
        return return_type;
    }
    ExecutableFunctionPtr prepare(const ColumnsWithTypeAndName &) const override
    {
        return std::make_unique<ExecutableFunctionNow>(time_value);
    }
    bool isDeterministic() const override { return false; }
    bool isDeterministicInScopeOfQuery() const override { return true; }
    bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & ) const override { return false; }
private:
    time_t time_value;
    DataTypes argument_types;
    DataTypePtr return_type;
};
class NowOverloadResolver : public IFunctionOverloadResolver