1 -- this snippet will erase all DVD media after 13th one!
5 select id,dvd_nr,total_size,username from archive order by dvd_nr;
7 delete from archive where dvd_nr > 13 ;
9 select id,dvd_nr,total_size,username from archive order by dvd_nr;
11 select setval('dvd_nr', (select max(dvd_nr) from archive)) ;