Abstract: A method and system for evaluating a path query are disclosed. The path query corresponds to a query tree including a plurality of query nodes. At least one query node corresponds to at least one predicate and is at a level. The predicate(s) are evaluated for previous query node(s). The method and system include scanning data nodes of a document and determining if the data nodes match the query nodes. The method and system also include placing data related to the data node in match stacks corresponding to matched query nodes. The data for the query node(s) include attribute(s) corresponding to the predicate(s). The method and system further include propagating a matching of the at least one query node backward to a matching of the at least one previous query node.

Abstract: Disclosed is method for processing an aggregate function. Rows that contain a reference to intermediate result structures are grouped to form groups. For each group, aggregate element structures are formed from the intermediate result structures and, if the aggregate function specifies ordering, the aggregate element structures are sorted based on a sort key.

Abstract: In one embodiment, at least a portion of an object model having at least one namespace is serialized. An ancestor namespace is searched for based on a current namespace declaration. The ancestor namespace is associated with an ancestor prefix and an ancestor uniform resource indicator (URI). The current namespace is associated with a current prefix and current URI. The search is performed to find an ancestor prefix matches the current prefix. When the current namespace is an implicit no default namespace and the ancestor namespace is an explicit default namespace based on, at least in part, the ancestor prefix, a serialized namespace declaration is generated for the current namespace.