Abstract: A method for estimating aggregates over a stream of axis-aligned rectangles, includes: decomposing the stream along one-dimensional intervals, wherein vertices for the rectangle are located in a predetermined grid; assigning each grid row to buckets, wherein the one-dimensional intervals are placed into buckets according to the corresponding rows in which the one-dimensional intervals are positioned; and estimating a sum of a number of grid points touched by at least one of the rectangles in each row of the grid to approximate a volume of the axis-aligned rectangles by: using pairwise-independent hash functions in a multi-dimensional algorithm to determine buckets that include a first interval corresponding to a given rectangle, wherein the interval has hash function results that meet a predetermined threshold; and inserting a second interval for the rectangle corresponding to the first interval into a one-dimensional algorithm for the corresponding bucket meeting the predetermined threshold.

Abstract: Described herein are approaches for computing correlated aggregates. An aspect provides for receiving a stream of data elements at a device, each data element having at least one numerical attribute; maintaining in memory plurality of tree structures comprising a plurality of separate nodes for summarizing numerical attributes of the data elements with respect to a predicate value of a correlated aggregation query, said maintaining comprising: creating the plurality of tree structures in which each node implements one of: a probabilistic counter and a sketch, wherein said probabilistic counter and said sketch each act to estimate aggregated data element numerical attributes to form a summary of said numerical attributes; and responsive to a correlated aggregation query specifying said predicate value, using said plurality of tree structures as a summary of said data element numerical attributes to compute a response to said correlated aggregate query.

Abstract: A method for estimating aggregates over a stream of axis-aligned rectangles, includes: decomposing the stream along one-dimensional intervals, wherein vertices for the rectangle are located in a predetermined grid; assigning each grid row to buckets, wherein the one-dimensional intervals are placed into buckets according to the corresponding rows in which the one-dimensional intervals are positioned; and estimating a sum of a number of grid points touched by at least one of the rectangles in each row of the grid to approximate a volume of the axis-aligned rectangles by: using pairwise-independent hash functions in a multi-dimensional algorithm to determine buckets that include a first interval corresponding to a given rectangle, wherein the interval has hash function results that meet a predetermined threshold; and inserting a second interval for the rectangle corresponding to the first interval into a one-dimensional algorithm for the corresponding bucket meeting the predetermined threshold.

Abstract: Described herein are approaches for computing correlated aggregates. An aspect provides for receiving a stream of data elements at a device, each data element having at least one numerical attribute; maintaining in memory plurality of tree structures comprising a plurality of separate nodes for summarizing numerical attributes of the data elements with respect to a predicate value of a correlated aggregation query, said maintaining comprising: creating the plurality of tree structures in which each node implements one of: a probabilistic counter and a sketch, wherein said probabilistic counter and said sketch each act to estimate aggregated data element numerical attributes to form a summary of said numerical attributes; and responsive to a correlated aggregation query specifying said predicate value, using said plurality of tree structures as a summary of said data element numerical attributes to compute a response to said correlated aggregate query.

Abstract: Systems and methods for optimizing code may use transactional memory to optimize one code section by forcing another code section to execute atomically. Application source code may be analyzed to identify instructions in one code section that only need to be executed if there exists the possibility that another code section (e.g., a critical section) could be partially executed or that its results could be affected by interference. In response to identifying such instructions, alternate code may be generated that forces the critical section to be executed as an atomic transaction, e.g., using best-effort hardware transactional memory. This alternate code may replace the original code or may be included in an alternate execution path that can be conditionally selected for execution at runtime. The alternate code may elide the identified instructions (which are rendered unnecessary by the transaction) by removing them, or by including them in the alternate execution path.

Abstract: Described herein are approaches for computing correlated aggregates. An aspect provides for receiving a stream of data elements at a device, each data element having at least one numerical attribute; maintaining in memory plurality of tree structures comprising a plurality of separate nodes for summarizing numerical attributes of the data elements with respect to a predicate value of a correlated aggregation query, said maintaining comprising: creating the plurality of tree structures in which each node implements one of: a probabilistic counter and a sketch, wherein said probabilistic counter and said sketch each act to estimate aggregated data element numerical attributes to form a summary of said numerical attributes; and responsive to a correlated aggregation query specifying said predicate value, using said plurality of tree structures as a summary of said data element numerical attributes to compute a response to said correlated aggregate query.

Abstract: Described herein are approaches for computing correlated aggregates. An aspect provides for receiving a stream of data elements at a device, each data element having at least one numerical attribute; maintaining in memory plurality of tree structures comprising a plurality of separate nodes for summarizing numerical attributes of the data elements with respect to a predicate value of a correlated aggregation query, said maintaining comprising: creating the plurality of tree structures in which each node implements one of: a probabilistic counter and a sketch, wherein said probabilistic counter and said sketch each act to estimate aggregated data element numerical attributes to form a summary of said numerical attributes; and responsive to a correlated aggregation query specifying said predicate value, using said plurality of tree structures as a summary of said data element numerical attributes to compute a response to said correlated aggregate query.

Abstract: Described herein are methods, systems, apparatuses and products for random sampling from distributed streams. An aspect provides a method for distributed sampling on a network with a plurality of sites and a coordinator, including: receiving at the coordinator a data element from a site of the plurality of sites, said data element having a weight randomly associated therewith deemed reportable by comparison at the site to a locally stored global value; comparing the weight of the data element received with a global value stored at the coordinator; and performing one of: updating the global value stored at the coordinator to the weight of the data element received; and communicating the global value stored at the coordinator back to the site of the plurality of sites. Other embodiments are disclosed.

Abstract: Described herein are methods, systems, apparatuses and products for random sampling from distributed streams. An aspect provides a method for distributed sampling on a network with a plurality of sites and a coordinator, including: receiving at the coordinator a data element from a site of the plurality of sites, said data element having a weight randomly associated therewith deemed reportable by comparison at the site to a locally stored global value; comparing the weight of the data element received with a global value stored at the coordinator; and performing one of: updating the global value stored at the coordinator to the weight of the data element received; and communicating the global value stored at the coordinator back to the site of the plurality of sites. Other embodiments are disclosed.

Abstract: Systems and methods for optimizing code may use transactional memory to optimize one code section by forcing another code section to execute atomically. Application source code may be analyzed to identify instructions in one code section that only need to be executed if there exists the possibility that another code section (e.g., a critical section) could be partially executed or that its results could be affected by interference. In response to identifying such instructions, alternate code may be generated that forces the critical section to be executed as an atomic transaction, e.g., using best-effort hardware transactional memory. This alternate code may replace the original code or may be included in an alternate execution path that can be conditionally selected for execution at runtime. The alternate code may elide the identified instructions (which are rendered unnecessary by the transaction) by removing them, or by including them in the alternate execution path.