Quoting from AUTHOR Tim Gorman: > With the LEAD() windowing function, it's not really necessary to store > END_DATE, as long as it is implied by the next record's START_DATE > value. Of course, if periods overlap, then END_DATE would still be > necessary... > > select ..., > start_date, > lead(start_date) over (order by start_date) > - (1/86400) end_date, > ..., ... > from ... > order by ... > Cripes! That saves me a bundle of SQL in another problem I was having. Thanks a million! I really gotta spend some time reviewing these analytical functions: there is a gold mine of reduced DML in them. -- //www.freelists.org/webpage/oracle-l