Sorting by source event time

[Noel OConnor]

Hi,
I have a temporary view created from a datastream.

        tableEnv.createTemporaryView("productDetailsView", productStream,
                Schema.newBuilder()
                        .columnByMetadata("eventTime",
"TIMESTAMP_LTZ(3)", "rowtime", Boolean.TRUE)
                        .watermark("eventTime", "SOURCE_WATERMARK()")
                        .build());


and i'm trying to sort it using the following

Table resultTable2 = tableEnv.sqlQuery(
        "SELECT * FROM productDetailsView ORDER BY eventTime DESC");

but I get the following error

Caused by: org.apache.flink.table.api.TableException: Sort on a
non-time-attribute field is not supported.

Can you sort on event time or does it have to be part of the actual
payload data type?
Have I missed something obvious ?

cheers
Noel