Abstract: A system, method and computer-readable medium are disclosed for identifying representative data using sketches. The method embodiment comprises generating a plurality of vectors from a data set, modifying each of the vectors of the plurality of vectors and selecting one of the plurality of generated vectors according to a comparison of a summed distance between a modified vector associated with the selected generated vector and remaining modified vectors. Modifying the generated vectors may involve reduced each generated vector to a lower dimensional vector. The summed distance then represents a summed distance between the lower dimensional vector and remaining lower dimensional vectors.

Abstract: The present invention relates to a method and apparatus for optimizing queries. The present invention discloses an efficient method for providing answers to queries under parametric aggregation constraints.

Abstract: A method and apparatus for ranked join indices includes a solution providing performance guarantees for top-k join queries over two relations, when preprocessing to construct a ranked join index for a specific join condition is permitted. The concepts of ranking join indices presented herein are also applicable in the case of a single relation. In this case, the concepts herein provide a solution to the top-k selection problem with monotone linear functions, having guaranteed worst case search performance for the case of two ranked attributes and arbitrary preference vectors.

Abstract: A vast amount of information currently accessible over the Web, and in corporate networks, is stored in a variety of databases, and is being exported as XML data. However, querying this totality of information in a declarative and timely fashion is problematic because this set of databases is dynamic, and a common schema is difficult to maintain. The present invention provides a solution to the problem of issuing declarative, ad hoc XPath queries against such a dynamic collection of XML databases, and receiving timely answers. There is proposed a decentralized architectures, under the open and the agreement cooperation models between a set of sites, for processing queries and updates to XML data. Each site consists of XML data nodes. (which export their data as XML, and also pose queries) and one XML router node (which manages the query and update interactions between sites). The architectures differ in the degree of knowledge individual router nodes have about data nodes containing specific XML data.

Abstract: A system, method and computer-readable medium are disclosed for identifying representative data using sketches. The method embodiment comprises generating a plurality of vectors from a data set, modifying each of the vectors of the plurality of vectors and selecting one of the plurality of generated vectors according to a comparison of a summed distance between a modified vector associated with the selected generated vector and remaining modified vectors. Modifying the generated vectors may involve reduced each generated vector to a lower dimensional vector. The summed distance then represents a summed distance between the lower dimensional vector and remaining lower dimensional vectors.

Abstract: Structural join mechanisms provide efficient query pattern matching. In one embodiment, tree-merge mechanisms are provided. In another embodiment, stack-tree mechanisms are provided.

Abstract: Structural join mechanisms provide efficient query pattern matching. In one embodiment, tree-merge mechanisms are provided. In another embodiment, stack-tree mechanisms are provided.

Abstract: A method of query pattern matching uses a chain of linked stacks to compactly represent partial results to root-to-leaf query paths, which are then composed to obtain matches for the twig pattern.

Abstract: Structural join mechanisms provide efficient query pattern matching. In one embodiment, tree-merge mechanisms are provided. In another embodiment, stack-tree mechanisms are provided.

Abstract: A system, method and computer-readable medium are disclosed for identifying representative data using sketches. The method embodiment comprises generating a plurality of vectors from a data set, modifying each of the vectors of the plurality of vectors and selecting one of the plurality of generated vectors according to a comparison of a summed distance between a modified vector associated with the selected generated vector and remaining modified vectors. Modifying the generated vectors may involve reduced each generated vector to a lower dimensional vector. The summed distance then represents a summed distance between the lower dimensional vector and remaining lower dimensional vectors.

Abstract: Approximate substring indexing is accomplished by decomposing each string in a database into overlapping “positional q-grams”, sequences of a predetermined length q, and containing information regarding the “position” of each q-gram within the string (i.e., 1st q-gram, 4th q-gram, etc.). An index is then formed of the tuples of the positional q-gram data (such as, for example, a B-tree index or a hash index). Each query applied to the database is similarly parsed into a plurality of positional q-grams (of the same length), and a candidate set of matches is found. Position-directed filtering is used to remove the candidates which have the q-grams in the wrong order and/or too far apart to form a “verified” output of matching candidates. If errors are permitted (defined in terms of an edit distance between each candidate and the query), an edit distance calculation can then be performed to produce the final set of matching strings.

Abstract: Certain exemplary embodiments provide a method comprising: automatically: receiving a plurality of elements for each of a plurality of continuous data streams; treating the plurality of elements as a first data stream matrix that defines a first dimensionality; reducing the first dimensionality of the first data stream matrix to obtain a second data stream matrix; computing a singular value decomposition of the second data stream matrix; and based on the singular value decomposition of the second data stream matrix, quantifying approximate linear correlations between the plurality of elements.

Abstract: A system, method and computer-readable medium are disclosed for identifying representative data using sketches. The method embodiment comprises generating a plurality of vectors from a data set, modifying each of the vectors of the plurality of vectors and selecting one of the plurality of generated vectors according to a comparison of a summed distance between a modified vector associated with the selected generated vector and remaining modified vectors. Modifying the generated vectors may involve reduced each generated vector to a lower dimensional vector. The summed distance then represents a summed distance between the lower dimensional vector and remaining lower dimensional vectors.

Abstract: The present invention relates to a method and apparatus for optimizing queries. The present invention discloses an efficient method for providing answers to queries under parametric aggregation constraints.

Abstract: A method of query pattern matching uses a chain of linked stacks to compactly represent partial results to root-to-leaf query paths, which are then composed to obtain matches for the twig pattern.

Abstract: A method and apparatus for ranked join indices includes a solution providing performance guarantees for top-k join queries over two relations, when preprocessing to construct a ranked join index for a specific join condition is permitted. The concepts of ranking join indices presented herein are also applicable in the case of a single relation. In this case, the concepts herein provide a solution to the top-k selection problem with monotone linear functions, having guaranteed worst case search performance for the case of two ranked attributes and arbitrary preference vectors.

Abstract: A method of adaptively evaluating a top-k query involves (1204) forming a servers having respective server queues storing candidate answers, processing (1322) the candidate answers, and (1232) providing a top-k set as a query evaluation. Processing includes (1402) adaptively choosing a winning server to whose queue a current candidate answer should be sent; (1404) sending the current candidate answer to the winning server's queue; (1334) adaptively choosing a next candidate answer to process from the winning server's queue; (1336) computing a join between the current candidate answer and next candidate answers at the winning server, so as to produce a new current candidate answer; and (1338) updating the top-k set with the new current candidate answer only if a score of the new current candidate answer exceeds a score of a top-k answer in a top-k set. A method of calculating scores for candidate answers is also provided.

Abstract: A framework defining a family of index structures useful in evaluating XML path expressions (i.e., twigs) in XML database is disclosed. Within this framework, two particular index structures with different space-time tradeoffs are presented that prove effective for the evaluation of twigs with value conditions. These index structures can be realized using access methods of an underlying relational database system. Experimental results show that the indices disclosed achieve significant improvement in performance for evaluating twig queries as compared with previously proposed XML path indices.

Abstract: Approximate substring indexing is accomplished by decomposing each string in a database into overlapping “positional q-grams”, sequences of a predetermined length q, and containing information regarding the “position” of each q-gram within the string (i.e., 1st q-gram, 4th q-gram, etc.). An index is then formed of the tuples of the positional q-gram data (such as, for example, a B-tree index or a hash index). Each query applied to the database is similarly parsed into a plurality of positional q-grams (of the same length), and a candidate set of matches is found. Position-directed filtering is used to remove the candidates which have the q-grams in the wrong order and/or too far apart to form a “verified” output of matching candidates. If errors are permitted (defined in terms of an edit distance between each candidate and the query), an edit distance calculation can then be performed to produce the final set of matching strings.

Abstract: A method and system for identifying representative data trends using sketches. A sketch is a lower dimensional vector used to represent higher dimensional data. The properties of sketches include data dimensionality reduction, sketches synthesized from other sketches, and the distance between sketches comparable to the distance between the data the sketches represent. Exemplary embodiments include identifying relaxed periods and average trends.