On Wed, 2009-02-04 at 14:42 +0800, Don Marvick wrote:
> 4. any other issue needs consideration?
Most attempts to improve sorting further have fallen to nothing because of the lack of repeatable test results. In particular, coming up with test cases *after* writing the code is a good way to get lost in discussions and have your work passed over.
The best starting point is to collect a number of test cases, both typical and extreme cases. Do some research to show that "typical" cases really are that and be prepared for some expressions of reasonable doubt. Publish that data so test results can be objectively verified and then measure those cases on existing code, with various settings of tunable parameters.
Then it will be a simple matter to prove your changes are effective in target cases without damaging other cases. We would also want the changes to work automatically without additional tunable parameters.
-- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support
