re: INFORMIX disk mirroring across LANs

Bill Williams kicks pretty hard against Al PArker's desire for remote mirroring. I get the impression that Bill is a bit out of date on network reliability (the only way you can connect discs at all to ICL's mainframes is through a network, and we don't see any problems arising from that). And a bit out of date on the cost of loss of data: some people will be willing to pay a small performance penalty to reduce the probability of total loss of the database by a few oreders of magnitude (mirroring to another disc a couple of feet away does nothing to protect you from fire, flood, earthquake, or explosion - you need a few kilometres for that, so it has to be a network). It's a bit surprising given his address (....af.mil) as his outfit is one of those who were interested in mirroring remote enough to keep the system up after a 20 Mton direct hit on the primary copy of the data. Hoping that features to provide extra assurance of data availability never get implemented seems just plain crazy to me. Of course he's right that simple physical mirroring is going to be best (that's just the KISS principle) so we don't want it in the DBMS, we want it in the underlying platform; but the platform ought to be able to provide mirroring across a network (or at any rate, across a 5km link - - needless to say, ICL's platforms do - OUR air force insists on it).