Here is the performance stats of the solution by David Betteridge for TSQL Challenge20.
| Attempt | Start Time | Reads | Writes | CPU | Duration (Sec) |
| 1 | Apr 21 2010 11:16PM | 835 | 0 | 16 | 0.0150 |
| 2 | Apr 21 2010 11:46PM | 835 | 0 | 16 | 0.0340 |
| 3 | Apr 22 2010 12:16AM | 835 | 0 | 15 | 0.0170 |
| 4 | Apr 22 2010 12:46AM | 835 | 0 | 16 | 0.0150 |
| 5 | Apr 22 2010 1:16AM | 835 | 0 | 15 | 0.0850 |