time_ordered_set mnesia table (was: ordered_bag mnesia tables)

Chandru <>
Fri Dec 3 12:18:56 CET 2010


Sorry, I posted earlier with the wrong subject.

------------------

Hello OTP team,

Would it possible to have a new type of mnesia table called
'time_ordered_set'. So the important properties of such a table would
be:

 * Records are always appended to the table (which means when I
traverse the table using the many mnesia functions available, the
ordering is predictable)
 * When inserting a record with a key which already exists, the old
record is removed before inserting the new record (atomically even for
dirty writes)

I know this can be achieved using a unique value such as now() for the
primary key, but then duplicate management becomes extra work as
secondary indices have to be used, and a lookup using the secondary
key has to be done before every insert etc.

cheers
Chandru


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