Here is the performance stats of the solution by leszek_g for TSQL Challenge20.
| Attempt | Start Time | Reads | Writes | CPU | Duration (Sec) |
| 1 | Apr 21 2010 11:25PM | 7252 | 0 | 46 | 0.0520 |
| 2 | Apr 21 2010 11:55PM | 7252 | 0 | 32 | 0.0670 |
| 3 | Apr 22 2010 12:25AM | 7252 | 0 | 32 | 0.0410 |
| 4 | Apr 22 2010 12:55AM | 7252 | 0 | 63 | 0.0620 |
| 5 | Apr 22 2010 1:25AM | 7252 | 0 | 47 | 0.0620 |