Then,analyzed and compared the data resource availability of several familiar database systems.

The paper expounds data usability problems in data warehouse,analyses the merits and shortages of some methods,and introduces an ideal scheme——Emulation Strategy,including its primary thinking,detailed realization process and related key technologies,future research direction of data usability is also presented.

Research on Data Availability and Security in Peer-to-Peer Storage System;

Simulation results show that the algorithm can significantly enhance the data availability,even when the node reliability is low.

Business continuity and data availability are important problems in relation to enterprise survival.

The fluctuation of resources available in the Internet environment can be adapted by migration of application components,but the issues of component transparent addressing and component consistency during such a component migration should be solved.

The status of biodiversity and its data resources and information system in China;

Through the investigation of the watershed monitoring data resources,the project confirms sources,quality,resources sharing approaches and issues of the soil and water conservation monitoring data in Yellow River Basin.

Scientific data resources is the basis of scientific data sharing, and the development of agricultural science data resources is the core content for the construction of agricultural science data centre.