Figure 2. Estimated cost of plan VS Actual cost of plan

From

Evaluating Query Execution Plans by Implementing Join Operators using Particle Swarm Optimization

Sambit Kumar Mishra, Srikanta Pattnaik, Dulu Patnaik

Journal of Computer Sciences and Applications. 2014, 2(2), 31-35 doi:10.12691/jcsa-2-2-3