摘要:
Disclosed is a technique for building an index in which global analysis computations and index creation are pipelined, wherein the global analysis computations share intermediate results.
摘要:
A system and method are provided for eliciting interesting structure from a collection of entities or resources with explicit and/or implicit, static and/or dynamic relations, called “affinities,” between them. Interesting structure includes (1) notions of quality, authority, or definitiveness of information, (2) notions of relevance to a user's information need, (3) notions of similarity among the plurality of resources retrieved from a universe of resources by a query process, and (4) notions of similarity among the usages of resources by different users/servers. Similarities between entities are computed, based on similarities between the affinity values for the entities. That is, where the affinitiy values for two entities resemble each other, the two entities have a high degree of similarity. Using the similarities, the entities are ranked, clustered, etc., based on a significance derived from the similarities. The ranking, clustering, etc., makes up the interesting structure which is sought.
摘要:
A method and system for identifying groups of pages of common interest from a collection of hyper-linked pages are disclosed. A plurality of community cores are identified from the collection where each core includes first and second sets of pages, and each page in the first set points to every page in the second set. Each identified core is expanded into a full community which is a subset of the pages regarding a particular topic. The identification community cores is based on the analysis of the Web graph in which the communities correspond to instances of Web subgraphs. Extraneous pages are then pruned to improve the quality of the resulting communities.
摘要:
A method for cataloging, filtering and ranking information, as for example, World Wide Web pages of the Internet. The method is preferably implemented in computer software and features steps for enabling a user to interactively create an information database including preferred information elements such as preferred-authority World Wide Web pages. The method includes steps for enabling a user to interactively create a frame-based, hierarchical organizational structure for the information elements, and steps for identifying and automatically filtering and ranking by relevance, information elements, such as World Wide Web pages for populating the structure, to form, for example, a searchable, World Wide Web page database. Additionally, the method features steps for enabling a user to interactively define a frame-based, hierarchical information structure for cataloging information, identifying a preliminary population of information elements for a particular hierarchical category arranged as a frame, based upon the respective frame attributes, and thereafter, expanding the information population to include related information, and subsequently, automatically filtering and ranking the information based upon relevance, and then populating the hierarchical structure with a definable portion of the filtered, ranked information elements.
摘要:
A system and method for joining a build table to a probe table in response to a query for data includes over partitioning the build table into “N” build partitions using a uniform hash function and writing the build partitions into main memory of a database computer. When the main memory becomes full, one or more partitions is selected as a victim partition to be written to disk storage, and the process continues until all build table rows or tuples have either been written into main memory or spilled to disk. Then, a packing algorithm is used to initially designate never-spilled partitions as “winners” and spilled partitions as “losers”, and then to randomly select one or more winners for prospective swapping with one or more losers. The I/O savings associated with each prospective swap is determined and if any savings would be realized, the winners are designated as losers the losers are designated as winners. The swap determination can be made multiple times, e.g., 256, after which losers are moved entirely to disk and winners are moved entirely to memory. At the end of the swapping, probe table rows associated with winner partitions are joined to rows in the winner build partitions while probe table rows associated with loser partitions are spilled to disk. Then, the loser build partitions are written to main memory for joining with corresponding probe table partitions, to undertake the requested join of the build table and probe table in an I/O- and memory-efficient manner.
摘要:
Techniques are disclosed for synchronizing a primary data system with an auxiliary data system that processes data for the primary data system. In one embodiment, how current the primary data system and the auxiliary data system are is determined. Requests sent from the primary data system that were not processed by the auxiliary data system are determined. The requests are resent to the auxiliary data system for processing.
摘要:
Provided are techniques for partitioning a physical index into one or more physical partitions; assigning each of the one or more physical partitions to a node in a cluster of nodes; for each received document, assigning an assigned-doc-ID comprising an integer document identifier; and, in response to assigning the assigned-doc-ID to a document, determining a cut-off of assignment of new documents to a current virtual-index-epoch comprising a first set of physical partitions and placing the new documents into a new virtual-index-epoch comprising a second set of physical partitions by inserting each new document to a specific one of the physical partitions in the second set using one or more functions that direct the placement based on one of the assigned-doc-id, a field value derived from a set of fields obtained from the document, and a combination of the assigned-doc-id and the field value.
摘要:
A dynamic Bloom filter comprises a cascaded set of Bloom filters. The system estimates or guesses a cardinality of input items, selects a number of hash functions based on the desired false positive rate, and allocates memory for an initial Bloom filter based on the estimated cardinality and desired false positive rate. The system inserts items into the initial Bloom filter and counts the bits set as they are inserted. If the number of bits set in the current Bloom filter reaches a predetermined target, the system declares the current Bloom filter full. The system recursively generates additional Bloom filters as needed for items remaining after the initial Bloom filter is filled; items are checked to eliminate duplicates. Each of the set of Bloom filters is individually queried to identify a positive or negative in response to a query. When the system is configured such that the false positive rate of each successive Bloom filter is decreased by one half, the system guarantees a false positive rate of at most twice the desired false positive rate.
摘要:
Provided are techniques for partitioning a physical index into one or more physical partitions; assigning each of the one or more physical partitions to a node in a cluster of nodes; for each received document, assigning an assigned-doc-ID comprising an integer document identifier; and, in response to assigning the assigned-doc-ID to a document, determining a cut-off of assignment of new documents to a current virtual-index-epoch comprising a first set of physical partitions and placing the new documents into a new virtual-index-epoch comprising a second set of physical partitions by inserting each new document to a specific one of the physical partitions in the second set using one or more functions that direct the placement based on one of the assigned-doc-id, a field value derived from a set of fields obtained from the document, and a combination of the assigned-doc-id and the field value.
摘要:
A cache-aware Bloom filter system segments a bit vector of a cache-aware Bloom filter into fixed-size blocks. The system hashes an item to be inserted into the cache-aware Bloom filter to identify one of the fixed-size blocks as a selected block for receiving the item and hashes the item k times to generate k hashed values for encoding the item for insertion in the in the selected block. The system sets bits within the selected block with addresses corresponding to the k hashed values such that accessing the item in the cache-aware Bloom filter requires accessing only the selected block to check the k hashed values. The size of the fixed-size block corresponds to a cache-line size of an associated computer architecture on which the cache-aware Bloom filter is installed.