Index Corruption - Online V5.02.UC1

> We are running Informix Online V5.02.Uc1 on HP-UX. We recently faced > an Index Corruption problem and after tbchecking we dropped and recreated > the Index and things are back to normal. > > The activity on the table was normal. The table sees only insert and > query activity. (No updates/deletes/index modifications). The table > had about 78000 rows and the chunks reside on LVM disks. The index > is made up of two fields and uses a descending clause. > > What I would like to know is a) what are the situations under which such > a corruption occurs and b) what ( if any) are the steps that can be > taken to eliminate/minimize such occurences. > > Thanks for all responses > Raj There are many things that cause corruption, some of which you can do something about. Cosmic rays and the MTBF catching up with you are just too bad (better have a good backup!) OTOH, I have seen indexes get corrupted from using all the locks (getting an overlock condition.) You usually know when this happens, as the whole engine shuts down. Prevent this by not doing massive interactive deletes/updates and by setting the number of locks way up from the default 2000 (the max is 1/4 million!) I don't recall seeing it in person, but I'll bet that exceeding other system limits could cause corruption. Just say "Whoa!" __________________________________________________________________ | Clem Akins Standard Disclaimers Apply | |Reynolds Metals Co, Alloys Plant "Climb High, Cave Deep!" | | Muscle Shoals, Alabama USA cwakins@leia.alloys.rmc.com | |________________________________________________________________|