Secondly since i have 3 outputs 2 have the same but only 1 different from both.those 2 values a constant values,how can i combine my two expressions so that it falls within 1 value..if not how can i group my XXX columns so that dog and cat cells merge together.. All replies.
DVD-R's hold 4,700 MB of data, a little more than 7 times that of CD-R's. Higher Order Cost: CD-R's hold fewer photos than DVD-R's. More disks will be needed if your placing a large order. Lower Order Cost: Because DVD-R's hold more photos you will need fewer disks when placing a large scanning order.
The long-term reliability of optical discs is still unknown, so there are no certain answers. All my backups are on write-once CD-R discs, which I reckon is the best bet for data you want to last 10 or more years. Their main limitation is that a CD will only store about 700MB of data. That was fine when I started, but it is becoming less viable every year.