CreateQuery min_max_with_nullable_string (children 3)
 Identifier min_max_with_nullable_string
 Columns definition (children 2)
  ExpressionList (children 2)
   ColumnDeclaration t (children 1)
    DataType DateTime
   ColumnDeclaration nullable_str (children 1)
    DataType Nullable (children 1)
     ExpressionList (children 1)
      DataType String
  ExpressionList (children 1)
   Index (children 2)
    Identifier nullable_str
    Function minmax (children 1)
     ExpressionList
 Storage definition (children 2)
  Function MergeTree
  Identifier t