摘要:
A method, system, and computer program product for normalized ranking of semantic query search results. The method commences by forming a SPARQL query, the SPARQL query specifying a collection of named RDF graphs, then executing the SPARQL query to retrieve matched documents selected from the collection of named RDF graphs. Having retrieved the matches, the method calculates an absolute normalized score for the matched document. The calculation of an absolute normalized score for a second matched document allows for relevance ranking. To enhance the relationship of the computer-calculated score to the relevance (and not solely to occurrence counts) embodiments consider the number of distinct variables selected in the SPARQL query, and also consider the total number of bindings to the aforementioned variables. For comparing from among possibly different sized documents, a further normalization component is implemented by considering the total number of triples found in the document's underlying subgraph.
摘要:
A database management system that has bitmap values in which set bits in a representation of a bitstring specify a set of objects whose definitions are built into the database management system. The database management system further includes user-accessible operations on the bitmap values. The bitmap values are represented by means of a mapping specifier that specifies a range of the set of objects and a representation of a string of bits that has been mapped onto the set of object specified by the range specifier. The representation of the string of bits may be compressed. Bitmap operations on the values may alter the range specifier, the size of the string of bits, or individual bits in the string of bits. The objects represented by the bitmap values may be objects in the database management system or objects external thereto. An example of bitmap values of the first kind are bitmap values representing sets of rowids. rowid bitmap values may be used to make a user-defined index of attribute values for any set of objects contained in fields in the database management system. An example of bitmap values of the second kind are bitmap values representing sets of electronic product codes. ePC bitmap values may be used in any application where a compact representation of a set of ePC codes is desired.
摘要:
A method, system, and computer program product provides improved performance for rebuild of user-defined indexes during partition maintenance operations (partition split, merge, and move). A method of maintaining a index of a partitioned database table comprises performing a partition maintenance operation on the partitioned database table wherein a plurality of rows of the partitioned database table are moved from one partition to another, storing mapping information for at least some of the plurality of moved rows, including an old mapping for each of the moved rows and a corresponding new mapping for each of the moved rows, and when rebuilding the index, replacing an old mapping in the index for each of the plurality of moved rows with the corresponding stored new mapping for each of the plurality of moved rows.
摘要:
Systems, methods, and other embodiments associated with visualizing data using summary graphs are described. One example method includes constructing a summary graph for display. The summary graph represents the data as a summary node having a plurality of property edges connected to the summary node. The summary node represents the set of values for the node in the data.
摘要:
A database management system that has bitmap values in which set bits in a representation of a bitstring specify a set of objects whose definitions are built into the database management system. The database management system further includes user-accessible operations on the bitmap values. The bitmap values are represented by means of a mapping specifier that specifies a range of the set of objects and a representation of a string of bits that has been mapped onto the set of object specified by the range specifier. Objects containing bitmap values may be indexed by means of an index tree that includes summary bitmap values.
摘要:
Systems, methodologies, media, and other embodiments associated with supporting queries with soft time constraints are described. One exemplary system embodiment includes logic for accepting a query having a soft time constraint. The example system may also include logic for rewriting the query having the soft time constraint into a query having a row limitation or a sample percentage limitation. In one example, the row limitation or sample percentage limitation are computed by repetitively comparing an estimated query execution time to the soft time constraint.
摘要:
Systems, methodologies, media, and other embodiments associated with supporting materialized views with user-defined aggregates are described. One example system includes logic for exposing a set of interface actions to support a user-defined aggregate in a materialized view associated with a base table. The materialized view may store both the user-defined aggregate and a user-defined aggregate context that facilitates logically connecting the user-defined aggregate to the base table. The example system may also include logic for supporting the user-defined aggregate. The support may be based on the set of interface actions. Example systems and methods may, therefore, facilitate incremental updating of the materialized view and/or rewriting a query to access the materialized view.
摘要:
A database management system that has bitmap values in which set bits in a representation of a bitstring specify a set of objects whose definitions are built into the database management system. The database management system further includes user-accessible operations on the bitmap values. The bitmap values are represented by means of a mapping specifier that specifies a range of the set of objects and a representation of a string of bits that has been mapped onto the set of object specified by the range specifier. Objects containing bitmap values may be indexed by means of an index tree that includes summary bitmap values.
摘要:
Systems, methodologies, media, and other embodiments associated with supporting queries with soft time constraints are described. One exemplary system embodiment includes logic for accepting a query having a soft time constraint. The example system may also include logic for rewriting the query having the soft time constraint into a query having a row limitation or a sample percentage limitation. In one example, the row limitation or sample percentage limitation are computed by repetitively comparing an estimated query execution time to the soft time constraint.
摘要:
Domain indexes (indexes created and maintained by user-defined indexing schemes) are managed on partitioned database objects that store data using a system-managed approach. Partition maintenance operations performed on the partitioned database objects cause corresponding partition maintenance operations to be performed on the domain indexes. Partition maintenance operations are performed on both the database objects and the indexes by a system-supplied partition manager. Changes in the partition maintenance operations or partitioning methods supplied by the database management system do not affect user-supplied code which is provided by the user-defined indexing scheme. User-supplied code is therefore partition operation-unaware.