Abstract: A method includes determining, using a processor, a set of aggregate queries to be executed on a data stream, the set of aggregate queries comprising queries that perform respective sets of aggregation operations on respective sets of attribute values over respective time intervals. The method also includes generating, using the processor, at least one intermediate aggregate query for a subset of the set of aggregate queries, the at least one intermediate aggregate query combining a subset of aggregation operations for the subset of aggregate queries and a subset of attribute values. The method further includes executing, using the processor, the at least one intermediate aggregate query to generate pre-aggregated data from the data stream for the subset of aggregate queries and executing, using the processor, the subset of aggregate queries subsequent to executing the at least one intermediate aggregate query on the pre-aggregated data.

Abstract: A system and method for caching and pre-fetching content is disclosed. This invention relates to mobile devices and, more particularly but not exclusively, to delivering content to a mobile device. Existing systems employ different mechanisms for delivering content such as multimedia and the like to users of mobile device. Mechanisms such as broadcast services, delivery from the interne, Wi-Fi hotspots, Bluetooth kiosks etc face problems of offering innovative services to users due to insufficient network capacity, high end costs to consumers. The disclosed system delivers contents such as multimedia, data and the like by pre-fetching and caching techniques. The contents preferred by a user is identified and pre-fetched to access points located in vicinity of the user. The user can access the contents from the access points via a short range communication means such as Bluetooth, Infrared and so on.

Abstract: A method of grouping nodes within a distributed network is provided. The example method includes performing a leader node self determination operation by which each node within the distributed network determines whether to become a leader node or a non-leader node, each leader node being the leader of a group including at least one node. Next, requests are sent, from each leader node, requesting at least one non-leader node to join the group associated with the leader node. First received requests are accepted, at each non-leader node, such that accepting non-leader nodes transition from a non-leader node to a dependent node dependent upon the requesting leader node. A next set of requests are sent, from each remaining non-leader node, requesting to join the group associated with at least one leader node. A determination is made, at each requested leader node, as to whether to accept the non-leader node into the group associated with the requested leader node.

Abstract: Improved techniques are disclosed for processing data stream queries wherein a data stream is obtained, a set of aggregate queries to be executed on the data stream is obtained, and a query plan for executing the set of aggregate queries on the data stream is generated. In a first method, the generated query plan includes generating at least one intermediate aggregate query, wherein the intermediate aggregate query combines a subset of aggregate queries from the set of aggregate queries so as to pre-aggregate data from the data stream prior to execution of the subset of aggregate queries such that the generated query plan is optimized for computational expense based on a given cost model. In a second method, the generated query plan includes identifying similar filters in two or more aggregate queries of the set of aggregate queries and combining the similar filters into a single filter such that the single filter is usable to pre-filter data input to the two or more aggregate queries.

Abstract: A method of grouping nodes within a distributed network is provided. The example method includes performing a leader node self determination operation by which each node within the distributed network determines whether to become a leader node or a non-leader node, each leader node being the leader of a group including at least one node. Next, requests are sent, from each leader node, requesting at least one non-leader node to join the group associated with the leader node. First received requests are accepted, at each non-leader node, such that accepting non-leader nodes transition from a non-leader node to a dependent node dependent upon the requesting leader node. A next set of requests are sent, from each remaining non-leader node, requesting to join the group associated with at least one leader node. A determination is made, at each requested leader node, as to whether to accept the non-leader node into the group associated with the requested leader node.