SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 3)
    Identifier ts
    Identifier metric
    Function nonNegativeDerivative (alias deriv) (children 1)
     ExpressionList (children 3)
      Identifier metric
      Identifier ts
      Function toIntervalMicrosecond (children 1)
       ExpressionList (children 1)
        Literal UInt64_4
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier nnd