摘要:
A method of updating a clone data map associated with a plurality of nodes of a computer system is disclosed. The clone data map includes node identification data and clone location data. A node failure event of a failed node of the computer system that supports a primary clone is detected. The clone data map is updated such that a secondary clone stored at a node other than the failed node is marked as a new primary clone. In addition, clone data maps may be used to perform node load balancing by placing a substantially similar number of primary clones on each node of a node cluster or may be used to increase or decrease a number of nodes of the node cluster. Further, data fragments that have a heavy usage or a large fragment size may be reduced in size by performing one or more data fragment split operations.
摘要:
A technique is described for storing data from a database across a plurality of data storage devices, wherein each data storage device is capable of being accessed only by a corresponding computer system in a group of interconnected computer systems. In accordance with the technique, an identifier of the database is received. An identifier of a storage tier instance is also received, wherein the storage tier instance comprises a logical representation of one or more storage locations within each of the data storage devices. Responsive to the receipt of the identifier of the database and the identifier of the storage tier instance, data from the database is stored in two or more of the storage locations logically represented by the storage tier instance, wherein each of the two or more storage locations in which data is stored is within a corresponding one of the data storage devices.
摘要:
Methods, systems, and computer-readable media are disclosed for transitioning clones and clone data access maps in response to node or media failure without blocking queries. In a system, a data request interface is configured to receive a query to access data at a storage device. Data management logic is configured to access clone state information of a plurality of clones including clones in a static state and clones in a transitory state. The data management logic is further configured to process the query to access the data according to the dynamic clone data access map, with functional correctness maintained.
摘要:
Methods, systems, and computer-readable media are disclosed for transitioning clones and clone data access maps in response to node or media failure without blocking queries. In a system, a data request interface is configured to receive a query to access data at a storage device. Data management logic is configured to access clone state information of a plurality of clones including clones in a static state and clones in a transitory state. The data management logic is further configured to process the query to access the data according to the dynamic clone data access map, with functional correctness maintained.
摘要:
A dataset is divided into pieces and stored at multiple locations and the system dynamically increases or decreases the number of storage locations where the pieces of the data set may be stored. A data structure comprises a first data field including a first index and a first element, and one or more data fields each with an index and an element. The elements of the one or more data fields include a token representing a location associated with the index of the first data field. A data row of a data set is mapped to the index of a data field using a second index. The second index is derived from a data row of the data set using a hash function. The second index is then mapped to the index of a data field included in the one or more data fields using a modulus function.
摘要:
A data structure and methods for dynamic fragment mapping are disclosed. A dataset may be divided into pieces and stored at multiple locations and the system may dynamically increase or decrease the number of storage locations where the pieces of the data set may be stored. The addition or removal of storage locations may cause only the data stored on those locations to be moved but the rest of the data may not be moved.The data structure comprises a first data field including a first index and a first element, and one or more data fields, each with an index and an element. The elements of the one or more data fields include a token representing a location associated with the index of the first data field. A data row of a data set may be mapped to the index of a data field using a second index. The second index may be derived from a data row of the data set using a hash function. The second index may then be mapped to the index of a data field included in the one or more data fields using a modulus function.
摘要:
Aspects of the subject matter described herein relate to deadlock detection in distributed environments. In aspects, nodes that are part of the environment each independently create a local wait-for graph. Each node transforms its local wait-for graph to remove non-global transactions that do not need resources from multiple nodes. Each node then sends its transformed local wait-for graph to a global deadlock monitor. The global deadlock monitor combines the local wait-for graphs into a global wait-for graph. Phantom deadlocks are detected and removed from the global wait-for graph. The global deadlock monitor may then detect and resolve deadlocks that involve global transactions.
摘要:
A computer-based method and system of processing records read respectively from first and second related tables of a database includes determining whether data contained in the records read from the first or second tables is unevenly distributed. Records corresponding to evenly distributed data are searched for matches using a first set of instances of the hash-join operator, and records corresponding to data which is unevenly distributed are searched for matches using a second set of instances of a hash-join operator.
摘要:
The present systems and methods disclose a system for personalizing computer functionality. End-users are provided with tools to easily write rich and complex preferences, for example, by using a plurality simple IF-THEN propositional logic. The preferences are then transformed into queries and executed efficiently on structured data. Preferences that are satisfied then execute actions such as providing notification or storing data in a particular folder. Furthermore, according to an aspect of the invention, data, logic, events, inter alia, are all schematized, thereby enabling sharing of data between application components and across applications.
摘要:
A computer-based method and system of processing records read respectively from first and second related tables of a database includes determining whether data contained in the records read from the first or second tables is unevenly distributed. Records corresponding to evenly distributed data are searched for matches using a first set of instances of the hash-join operator, and records corresponding to data which is unevenly distributed are searched for matches using a second set of instances of a hash-join operator.