Is it possible on i series that an index is defined keeping in mind an sql select criteriea however when the queryis run this index does not get used. We had an issue wherein an entire library had to be cleared and all files from had to be restored from a previous backup, after the backup was restored we found one of the sql queries taking much more time than before the restore , although all files and its logicals where restored.
We ran dbmon on the sql job, and it suggested creation of few indexes which we created using names specified by us and using the recommeded fields. However when the sql was submitted we did not find any of the indexes created by us being used. Why is that?