**Use case**

Workload generation with continuous queries.

**Describe the solution you'd like**

Similar to now() but non-constant.

{
public:
    explicit ExecutableFunctionNow(time_t time_) : time_value(time_) {}
    String getName() const override { return "now"; }
    ColumnPtr executeImpl(const ColumnsWithTypeAndName &, const DataTypePtr &, size_t input_rows_count) const override
    {
        return DataTypeDateTime().createColumnConst(
                input_rows_count,
                static_cast<UInt64>(time_value));
    }
private:
    time_t time_value;
};
class FunctionBaseNow : public IFunctionBase