A thought on Index Organized Tables

Hi,
As you all know, Index Organized tables are a way by which we can
automatically cluster the data based on the primary key. While i was
thinking about an implementation for postgres, it looks like an impossible
with the current ideologies. In an IOT, if a record gets updated, we need to
mark the old row as deleted immediately, as we do with any other table. But
since Postgres supports user defined data types and if they happen to be a
broken data type, then we have an unstable IOT.(as there is no guarantee, we
might hit the same record)
This was the reason for which, the proposal on creating indexes with
snapshot was rejected.
May i get a little clarification on this issue? Will we be supporting
the IOT feature in postgres in future?

Thanks,
Gokul.