> So my question is: is there a way to do some kind of whole-row
> comparison ? For instance a hash of the full row or something similar ?
> Is there a standard way of solving this problem ?
Sure it is called row wise comparison:
http://www.postgresql.org/docs/8.2/interactive/functions-comparisons.html#ROW-WISE-COMPARISON
you can write something like:
SELECT * FROM Your_tableWHERE (c1,c2,c3,c4) = ('a',2,'xyz',123);
Regards,
Richard Broersma Jr.