deferrable on unique

table t1: id integer primary key, seq integer not null unique

the seq is for ordering the rows as the user likes.  however, if the
rows are moved around, eg begin update t1 set seq=4 where id=5 update t1 set seq=5 where id=4 end
will bomb because the first update has two rows of seq=4 (although
correct after the transaction).

I thought "deferrable initally deferred" would fix this, but the phrase
is not allowed on unique.

is this correct?  any ideas?


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com