Automatic plan choice validation using performance statistics
Ashit Gosalia, Xin Zhang · 2008
The query optimizer models data distribution and access paths to make the optimal plan choice for a given query. Sometimes the plan selection is poor because of modeling limitations, outdated statistics, incorrect optimization heuristics, etc. Hence it is useful to examine the plan choice made by the optimizer from an execution perspective and to impose validation rules on the actual execution plan to evaluate plan suitability. This approach treats the optimizer as a black box. The plan validation is based on the queries and data instead of the optimizer implementation details.