TIMESTAMP WITH TIME ZONE in IOT

Hello everybody,

IOTs provides good performance, just due to restriction is not possible to use TSTZ in the key.

Maybe somebody knows, is there a way, how to create a IOT with TIMESTAMP WITH TIME ZONE in the key? We are running 11g.

SQL>

CREATE TABLE iottest

     (tstz  TIMESTAMP WITH TIME ZONE PRIMARY KEY,

      val  NUMBER)

  ORGANIZATION INDEX

ORA-02329: Spalte vom Datentyp TIME/TIMESTAMP WITH TIME ZONE kann kein eindeutiger oder Primärschlüssel sein

CREATE TABLE iottest

     (tstz  TIMESTAMP WITH TIME ZONE,

      utc_time as (sys_extract_utc(x)) PRIMARY KEY,

      val  NUMBER)

  ORGANIZATION INDEX

ORA-54008: Spaltenausdruck wird bei einer index-organisierten Tabelle nicht unterstützt