5. The method of claim 1 , wherein: the execution tree for the semantic web query comprises an access method and an execution node for each triple pattern in the semantic web query; and transforming the execution tree for the semantic web query into an equivalent entity-oriented storage query plan comprises merging execution nodes for triple patterns having at least one of a common subject and a common object into merged plan nodes.
5. The method of claim 1 , wherein: the execution tree for the semantic web query comprises an access method and an execution node for each triple pattern in the semantic web query; and transforming the execution tree for the semantic web query into an equivalent entity-oriented storage query plan comprises merging execution nodes for triple patterns having at least one of a common subject and a common object into merged plan nodes. 9. The method of claim 5 , wherein transforming the execution tree for the semantic web query into an equivalent entity-oriented storage query plan further comprises merging execution nodes only for which equivalent SQL statements exist for the merged plan nodes.