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 11:26PM | 294844 | 1 | 2340 | 2.8242 |
| 2 | Apr 21 2010 11:56PM | 294845 | 0 | 2371 | 7.5404 |
| 3 | Apr 22 2010 12:26AM | 294845 | 0 | 2230 | 4.8173 |
| 4 | Apr 22 2010 12:56AM | 294845 | 0 | 2371 | 9.1135 |
| 5 | Apr 22 2010 1:26AM | 294845 | 0 | 2277 | 6.6914 |