SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function JSONExtract (alias x) (children 1)
     ExpressionList (children 3)
      Function materialize (children 1)
       ExpressionList (children 1)
        Literal \'{"string_value":"Hello"}\'
      Function materialize (children 1)
       ExpressionList (children 1)
        Function toLowCardinality (children 1)
         ExpressionList (children 1)
          Literal \'string_value\'
      Literal \'LowCardinality(Nullable(String))\'