4. The method of claim 1 : wherein the database query comprises a plurality of sub-queries; and wherein optimizing the database query further comprises: analyzing each of the plurality of sub-queries based on in-memory cached statistics; identifying one of the plurality of sub-queries as a most efficient sub-query based on the in-memory cached statistics, and generating the optimized database query having the one sub-query identified as the most efficient sub-query as a leading query within the optimized database query.
4. The method of claim 1 : wherein the database query comprises a plurality of sub-queries; and wherein optimizing the database query further comprises: analyzing each of the plurality of sub-queries based on in-memory cached statistics; identifying one of the plurality of sub-queries as a most efficient sub-query based on the in-memory cached statistics, and generating the optimized database query having the one sub-query identified as the most efficient sub-query as a leading query within the optimized database query. 5. The method of claim 4 , wherein the most efficient query comprises the one sub-query among the plurality of sub-queries corresponding to a best metric or a best combination of metrics in accordance with the in-memory cached statistics, wherein each metric is selected from the group comprising: a number of rows, a number of blocks, an average row length; Input/Output (I/O) utilization; processor utilization; and execution time.