Problems with "ALTER FRAGMENT ON TABLE DETACH..."

Save me, please ! We are looking for options to problems we've had detaching fragments on very large tables, where the dbspace has a lot of rows in it.. Background: hpux 10.20 HP t500 with Informix IDS 7.30.uc6, table has 24 fragments each 6-7gb of data in 8gb dbspace. On a previous release (7.30.uc2) the detach would hang and never finish. While hanging it was not accumulating any cpu use. We are able to kill the session with onmode -z without any problems. Informix says, that's a bug in uc2, fixed in uc6. I still see the same hang. We don't want to go go to another release wight away (e.g. 7.31) for fear of something else breaking... We are in serious 24x7 production. We ARE able to delete the rows from the dbspace/fragment and issue "alter fragment blabla drop frag.." and that works almost instantly. Q. Can I use the alter fragment DROP with rows in the dbspace ? Q. Will a special update statistics be necessary before or after ? Q. Are there any know tricks to getting DETACH to work ? These are such huge tables (8gb fragments) and we peel off one a month we have to figure out what to do.... Steve Stubbe stubbe@madtech.com