1. An apparatus comprising: at least one processor; a memory coupled to the at least one processor; a database residing in the memory; a query engine residing in the memory and executed by the at least one processor, the query engine querying the database; a query execution data structure residing in the memory and executed by the query engine, the query execution data structure comprising a plurality of object oriented nodes, wherein each node includes a monitor method that enables collection of monitored data from the node and a dump method that outputs the monitored data; and a monitor and debug mechanism residing in the memory and executed by the at least one processor, wherein the monitor and debug mechanism comprises a graphical user interface that receives the monitored data from at least one dump method in the query execution data structure and displays corresponding information to a user, wherein the monitor and debug mechanism allows examining the monitored data as the query engine executes the query execution data structure.