Nulls in Informix vs Ora

Can someone explain the differences between the way Informix and Oracle treat nulls??? I used Oracle for two years and the buys on my project have been using it a lot longer. Just this year we fielded a new version of the system, under Unix with Informix. We rewrote the entire system in Hyperscript. I haven't done much of the ad hoc data analysis I used to do under Oracle. I have noticed problems with selecting nulls in a way I thought was proper. I understand there was a big flame/thread on the idea of nulls and what people think should be the proper way. I don't want to bring that back up. I'm just interested in knowing what Informix currently does so I can watch out for it . . . (My site doesn't archive a lot of messages so I can't find a discussion in my local searches). Thanks! raymond.bowers@wdn.com --- ' OLX 2.2 ' If the data doesn't fit the theory, fix the data.