Method and system for collaborative and dynamic query optimization in a DBMS network

A method, system, apparatus, and a computer program product are provided for optimizing database query plans generated from a received database query at a database management system by monitoring a global cost estimation function for one or more steps of the received database query to identify a first low-performing cost metric and collaboratively optimizing a query plan for the database query by comparing differences between the first low-performing cost metric and a second cost metric at an additional database management system, thereby generating an optimized query plan for the database management system that may be stored at the database management system along with corresponding information identifying a reason for rewriting the optimized query plan.