SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 5)
   ExpressionList (children 2)
    Identifier RegionID
    Function uniq (alias u) (children 1)
     ExpressionList (children 1)
      Identifier UserID
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier test.hits_s3
   ExpressionList (children 1)
    Identifier RegionID
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier u
   Literal UInt64_10