Adaptive Server optimization and plan generation evaluates the optimal path for executing a query and produces a query plan that tells the Adaptive Server how to execute the query.
If the update statistics command has been run for the tables in the query, the optimizer has sufficient data on which to base decisions regarding join order. If the update statistics command has not been run, the Adaptive Server defaults apply.
For more information on Adaptive Server optimization, refer to Chapter 7, “The Adaptive Server Query Optimizer,” in the Performance and Tuning Guide.
