摘要:
A database system includes a locking mechanism for a materialized view defined on base relations. In response to updates of a base relation, a predefined lock (e.g., Y lock or IY lock) is placed on the materialized view. With the locking mechanism, transaction concurrency is enhanced by enabling concurrent updates of a materialized view by plural transactions in certain cases.
摘要:
A database system includes a transaction rescheduling mechanism that reorders pending transactions based on whether one or more of the pending transactions conflict with any transactions that have been scheduled for execution. In one arrangement, the received pending transactions are stored in a first queue. The transactions that are scheduled for execution are stored in a second queue. The transactions are moved from the first queue to the second queue based on the reordering by the transaction rescheduling mechanism.
摘要:
A database system is capable of processing a query and providing a progress indicator of the processing of the query based on at least a first cost factor. Initially, an estimate is set for the first cost factor. During processing of the query, the estimate of the first cost factor is updated to enable refinement of the progress indicator.
摘要:
Auxiliary relations are used to maintain a materialized view. The materialized view comprises results of some operation performed between two or more base relations of a parallel database management system comprising a plurality of nodes. The two or more base relations are distributed to the nodes according to some partitioning strategy. Each auxiliary relation is partitioned according to the join attribute in the materialized view definition. During join or other operations involving the relations, the auxiliary relations, not the base relations, are used to construct join results and to maintain the materialized view.
摘要:
A database system includes a locking mechanism for an aggregate materialized view defined on base relations. In response to updates of a base relation, predefined locks are placed on the aggregate materialized view. With locking mechanisms, transaction concurrency is enhanced by enabling concurrent updates of the materialized view by plural transactions in certain cases, while avoiding the situation in which multiple tuples belonging to the same group are integrated as separate tuples into the aggregate materialized view.
摘要:
A method and apparatus identifies SQL statements in a first transaction that specify modification operations that are commutative and associative. The SQL statements are combined into one SQL statement, and the one SQL statement is submitted to a database system. Optionally, or alternatively, multiple transactions can be grouped together into one transaction.
摘要:
Virtual hot plug systems and methods are described for Peripheral Component Interconnect (PCI), PCI Express (PCIe), and variants thereof. Specifically, the virtual hot plug systems and methods enable PCI related devices to support a hot plug configuration with such devices lacking hot plug controller hardware. The virtual hot plug systems and methods include intelligent polling logic for discovering the new PCI/PCIe devices with proper logic to access the hardware and avoid hanging or locking up the operating system.
摘要:
The automated social networking graph mining and visualization technique described herein mines social connections and allows creation of a social networking graph from general (not necessarily social-application specific) Web pages. The technique uses the distances between a person's/entity's name and related people's/entities names on one or more Web pages to determine connections between people/entities and the strengths of the connections. In one embodiment, the technique lays out these connections, and then clusters them, in a 2-D layout of a social networking graph that represents the Web connection strengths among the related people's or entities' names, by using a force-directed model.
摘要:
There are provided a system and method for resource adaptive, real-time new event detection. The method includes capturing, from among documents in a document streaming environment, first-story documents that mention previously unmentioned events. The method further includes dynamically adjusting a thoroughness of the capturing step by controlling a number of keywords and documents considered according to a real-time system load.
摘要:
The present invention relates to methods for the identification and characterization of compounds that modulate P-glycoprotein (P-gp) and the use of such methods for the identification and characterization of therapeutic agents. The invention further relates to a kit for performing such methods.