Data access

About: Data access is a research topic. Over the lifetime, 13141 publications have been published within this topic receiving 172859 citations. The topic is also known as: Data access.

Data access layer design and code generation

Abstract: A system and method that facilitate data access in a software development environment is provided. The system generates strongly typed objects that encapsulate raw, untyped data access logic and groups together like database commands in a common data access component. The system provides a mapping between database types and common language runtime data types including the impedance mismatch of null representations. The system configures data access component(s) that are employed at design-time to facilitate access to data object(s) by application(s) and allows a user of the configured data access component(s) to improve developer productivity and/or reduce the quantity of runtime errors introduced into code. The data access component can be instanced on multiple forms components and/or with the developer's own class(es). Thus, change(s) to a query and/or interface are accomplished within the data access component and be available to the forms components and/or object(s) that utilize the data access component.

Data access programming model for occasionally connected applications

Abstract: Portions of a computing environment (such as a user's mesh) may restrict accessing to particular types of access by particular applications The computer may support applications executing within a virtual environment (such as a web browser) by brokering such access through a token-based system When an application requests a particular type of access (eg, writing to a particular data object), the computer may contact an authorization server with the credentials of the application to request the specified access, and may receive and store an authorization token The computer may then access the computing environment with the authorization token, and may return the results to the application within the virtual environment Additional features may further support such applications; eg, a programmatic interface may be provided in a familiar language, such as JavaScript, whereby applications can request access to particular data objects and identify authorized access capabilities

Pattern-Direct and Layout-Aware Replication Scheme for Parallel I/O Systems

Abstract: The performance gap between computing power and the I/O system is ever increasing, and in the meantime more and more High Performance Computing (HPC) applications are becoming data intensive. This study describes an I/O data replication scheme, named Pattern-Direct and Layout-Aware (PDLA) data replication scheme, to alleviate this performance gap. The basic idea of PDLA is replicating identified data access pattern, and saving these reorganized replications with optimized data layouts based on access cost analysis. A runtime system is designed and developed to integrate the PDLA replication scheme and existing parallel I/O system; a prototype of PDLA is implemented under the MPICH2 and PVFS2 environments. Experimental results show that PDLA is effective in improving data access performance of parallel I/O systems.

Buffer system for controlled and timely delivery of MPEG-2 data services

Abstract: A data elementary buffer with underflow and overflow operational constraints is incorporated into a digital televison receiver to regulate the flow of data related to an ancillary data service to be presented in synchronization with a video or audio program element. The data elementary buffer ensures that data is received in time for decoding and presentation in synchronization with the video or audio element. The data elementary buffer also limits the amount of data that the receiver may be required to cache. The minimum size of the data elementary buffer is three times the size of a nominal data access unit or three times the quantity of data that the receiver can receive at the maximum rate in the period that a video element is displayed by the receiver.