17. A computer-readable storage medium having computer-readable code stored thereon for causing a device to perform a method of estimating a loaded execution runtime of a database query, said method comprising: receiving a database query to be executed on a database at a query receiver; receiving load information related to a load of said database at a database load information receiver; processing said database query through a prediction of query runtime tree to estimate a loaded execution runtime for executing said query upon said database at a tree traverser coupled with said query receiver and said database load information receiver, said query runtime tree comprising a plurality of nodes and at least one branching path between two nodes of said plurality of nodes; receiving historical query information related to historical database queries previously executed on said database at an historical query information receiver; and developing a loaded database query execution runtime classifier function from said historical query information, such that said classifier function is embodied within a prediction of query runtime tree at a machine learning module coupled with said historical query information receiver, said classifier function for determining said at least one branching path from at least one node of said plurality of nodes.
17. A computer-readable storage medium having computer-readable code stored thereon for causing a device to perform a method of estimating a loaded execution runtime of a database query, said method comprising: receiving a database query to be executed on a database at a query receiver; receiving load information related to a load of said database at a database load information receiver; processing said database query through a prediction of query runtime tree to estimate a loaded execution runtime for executing said query upon said database at a tree traverser coupled with said query receiver and said database load information receiver, said query runtime tree comprising a plurality of nodes and at least one branching path between two nodes of said plurality of nodes; receiving historical query information related to historical database queries previously executed on said database at an historical query information receiver; and developing a loaded database query execution runtime classifier function from said historical query information, such that said classifier function is embodied within a prediction of query runtime tree at a machine learning module coupled with said historical query information receiver, said classifier function for determining said at least one branching path from at least one node of said plurality of nodes. 18. The computer-readable storage medium of claim 17 , wherein developing a loaded database query execution runtime classifier function from said historical query information comprises: extracting at least one historical query feature related to an historical database query of said historical query information at an historical query feature extractor; determining a query plan vector and a system load vector for said historical database query at an historical query vector determiner coupled with said historical query feature extractor; and grouping a plurality of historical database queries of said historical database information into node and leaf elements of said prediction of query runtime tree at a prediction of query runtime tree builder coupled with said historical vector determiner, said grouping based upon execution runtimes of said historical database queries.