As the important of global data sharing is widely utilized in many corporations, it is well know as multidatabase. However, the system occurs and interesting issue. It is global constraint checking. It is mandatory to set up a potential checking application inside; therefore, global constraint checking needs these following essential characteristics such as 1) mobility 2) heterogeneity and 3) robustness. The effective way to implement the checking is using Aglets which is well recognized as one of the good mobile agent. Aglets is very appropriate because it contains the ability of mobility, and it is 100% Java compatible and open source. In this thesis, we construct the application of global constraint checking following these steps. To begin with starting step, user enters the insert statement. The system then receives the input, and then connection with Global Metadatabase begins. It will optimize the proper route for checking. Its optimized data will be sent out with the mobile agents to the remote sites. Eventually, results will be collected and show to user.

Résumé indisponible / Medical data management has become a real challenge due to the emergence of new imaging technologies providing high image resolutions.This thesis focuses in particular on the management of DICOM files. DICOM is one of the most important medical standards. DICOM files have special data format where one file may contain regular data, multimedia data and services. These files are extremely heterogeneous (the schema of a file cannot be predicted) and have large data sizes. The characteristics of DICOM files added to the requirements of medical data management in general – in term of availability and accessibility- have led us to construct our research question as follows:Is it possible to build a system that: (1) is highly available, (2) supports any medical images (different specialties, modalities and physicians’ practices), (3) enables to store extremely huge/ever increasing data, (4) provides expressive accesses and (5) is cost-effective .In order to answer this question we have built a hybrid (row-column) cloud-enabled storage system. The idea of this solution is to disperse DICOM attributes thoughtfully, depending on their characteristics, over both data layouts in a way that provides the best of row-oriented and column-oriented storage models in one system. All with exploiting the interesting features of the cloud that enables us to ensure the availability and portability of medical data. Storing data on such hybrid data layout opens the door for a second research question, how to process queries efficiently over this hybrid data storage with enabling new and more efficient query plansThe originality of our proposal comes from the fact that there is currently no system that stores data in such hybrid storage (i.e. an attribute is either on row-oriented database or on column-oriented one and a given query could interrogate both storage models at the same time) and studies query processing over it.The experimental prototypes implemented in this thesis show interesting results and opens the door for multiple optimizations and research questions.