Abstract:
Various embodiments for maintaining security and confidentiality of data and operations within a fraud detection system. Each of these embodiments utilizes a secure architecture in which: (1) access to data is limited to only approved or authorized entities; (2) confidential details in received data can be readily identified and concealed; and (3) confidential details that have become non-confidential can be identified and exposed.
Abstract:
Techniques are disclosed for selecting a delete-safe compression method for a plurality of delta encoded data values (e.g., delta encoded integers or deltas). For example, a computer-implemented method for selecting an optimal delete-safe compression algorithm from among two or more compression algorithms for use on a plurality of delta encoded data values includes the following steps. The maximum number of data values eliminated by each of the two or more compression algorithms is computed. For the plurality of delta encoded data values to be compressed, the minimum size of the plurality of delta encoded data values before compression thereof is computed. A delete-safe threshold value is computed based on the minimum size of the plurality of delta encoded data values. Then, the compression algorithm is selected from the two or more compression algorithms that achieves the delete-safe threshold value.
Abstract:
A method (and structure) of storing schema-less data of a dataset in a relational database, includes constructing a hash table for the schema-less data, using a processor on a computer. Data in the dataset is stored in a tuple format including a subject along with at least one other entity associated to the subject. Each row of the hashtable will be dedicated to a subject of the dataset, and at least one of the at least one other entity associated with the subject in the row is to be stored in a pair-wise manner in that row of the hashtable. In an exemplary embodiment, RDF data that uses triples (subject, predicate, object) is stored with the predicate/object stored in the pair-wise manner in its associated subject row.
Abstract:
A method for accelerating range queries using periodic monotonic properties of non-monotonic functions including mapping a base column x to an existing index on a column y that is correlated with column x through a periodic piecewise monotonic function F(x), rewriting an index construction statement to force the existing index on column y to track a periodic piecewise monotonic property by assigning identical values of F(x) to different periods to different ranges to create an annotated index, and rewriting range queries over the annotated index on F(x) by modifying a derived predicate.
Abstract:
A method and system utilizes a hierarchical bitmap structure to represent deleted data sets. Each level in the hierarchical bitmap structure may have progressively larger size and represent finer granularity of number of data blocks than its parent level. A method in one aspect may comprise allocating a first level bitmap having size equal to a register on a processor, each bit in the first level bitmap representing a plurality of blocks of data in a database, and allocating one or more pointers corresponding to said plurality of bits in the first level bitmap, said one or more pointers being allocated to point to a sub bitmap generated after a data block is deleted but before the index corresponding to the data block is cleaned.
Abstract:
A multi-level locking hierarchy for a relational database includes a locking level applied to a multi-dimensionally clustering table, a locking level applied to blocks within the table, and a locking level applied to rows within the blocks. The hierarchy leverages the multi-dimensional clustering of the table data for efficiency and to reduce lock overhead. Data is normally locked in order of coarser to finer granularity to limit deadlock. When data of finer granularity is locked, data of coarser granularity containing the finer granularity data is also locked. Block lock durations may be employed to ensure that a block remains locked if any contained row remains locked. Block level lock attributes may facilitate detection of at least one of a concurrent scan and a row deletion within a block. Detection of the emptying of a block during a scan of the block may bar scan completion in that block.
Abstract:
Multidimensional clustered tables are provided for efficient processing and management in a relational database management system. A multidimensional clustered table is one whose data is simultaneously clustered along one or more independent dimensions, or clustering keys, and physically organized into blocks or pages on disk. When such a table is created, one can specify one or more keys as dimensions along which to cluster the table's data. Each of the dimensions can consist of one or more columns. Further provided are efficient query processing and maintenance techniques for use in conjunction with multidimensional clustered tables.
Abstract:
A method, information processing system, and computer program storage product optimize the placement of database objects on a multiplicity of storage devices. A set of database objects are placed on a first storage device in a multiplicity of storage devices. Each storage device comprises differing characteristics. A query workload is run on the set of database objects that have been placed on the first storage device. Profiling information associated with the query workload that is running is collected. A subset of database objects is selected from the set of the database objects to be stored on a second storage device. The second storage device is a separate physical device from, and performs faster than, the first storage device. The subset of database objects is stored on the second storage device and all remaining database objects in the set of database objects on the first storage device.
Abstract:
Techniques are disclosed for encoding a variable length structure such that it facilitates forward and reverse scans of a list of such structures as needed. While the techniques are applicable to a wide variety of applications, they are particularly well-suited for use with structures such as those found in compressed database indexes. For example, a computer-implemented method for processing one or more variable length data structures includes the following steps. Each variable length data structure is obtained. Each variable length structure comprises one or more data block. A variable length encoding process is applied to the one or more blocks of each variable length data structure which comprises setting a continuation data value in each block to a first value or a second value, wherein the setting of the continuation data values enables bi-directional scanning of each variable length structure.
Abstract:
Disclosed are a method, information processing system, and computer readable medium for scanning a storage medium table. The method includes retrieving location information associated with at least one other storage medium table scan. A storage medium table scan is started at a location within a storage medium table based on at least a location of the one other storage medium table scan. A weight is assigned to at least one storage medium block based on at least a current scanning location within the storage medium table relative to the location of the one other table scan. The method determines if a distance between the current scanning location and the location of the one other table scan is greater than a first given threshold. A current scanning operation is delayed, in response to the distance being greater than the given threshold, until the distance is below a second given threshold.