As a testament to what Don said, a few years ago I asked a friend who worked
at Publix [major Florida based grocery chain] about the new building going
up a the back of an area near where he worked. He said an internal study
showed that a computer system failure would most likely cause the
The redundancy that most major retail chains have isn't that sophisticated. I
worked on site systems for Target and K-Mart some years back, and this was the
gist of what they did:
POS (point of sale) systems loaded their data in real time to a local server.
The local server used a RAID
