系统内冗余或重复数据的度量，表明存储和潜在性能问题效率低下。
1 DC = 0.25 PB
1 PB = 4 DC
例子:
将15 数据压缩转换为奇偶校验的冗余：
15 DC = 3.75 PB
| 数据压缩 | 奇偶校验的冗余 |
|---|---|
| 0.01 DC | 0.003 PB |
| 0.1 DC | 0.025 PB |
| 1 DC | 0.25 PB |
| 2 DC | 0.5 PB |
| 3 DC | 0.75 PB |
| 5 DC | 1.25 PB |
| 10 DC | 2.5 PB |
| 20 DC | 5 PB |
| 30 DC | 7.5 PB |
| 40 DC | 10 PB |
| 50 DC | 12.5 PB |
| 60 DC | 15 PB |
| 70 DC | 17.5 PB |
| 80 DC | 20 PB |
| 90 DC | 22.5 PB |
| 100 DC | 25 PB |
| 250 DC | 62.5 PB |
| 500 DC | 125 PB |
| 750 DC | 187.5 PB |
| 1000 DC | 250 PB |
| 10000 DC | 2,500 PB |
| 100000 DC | 25,000 PB |
规则