Integração de Banco de Dados em Ambientes de Grid

Grid systems have been1 recently utilized by researchers worldwide. Several hardware and software infrastructures make it possible to develop the so-called e-Science. These systems can be classified in two big groups: computational grids and datagrids. Many systems have been developed whose focus is on computational grids, however very few have been dedicated to datagrids. Some solutions have been developed for the orchestration of file systems and few concentrate on the orchestration of databases. Systeins such as AMGA, GREIC and OGSA-DAI (the latter one developed in the context of the Open Grid Forum - OGF), offer solutions that make local data available in grid environments, or integrate heterogeneous and distributed databases. Most often, these solutions require that the user knows the physycal location of the table or the kind of database being utilised in the remote grid node. In this work we offer another solution that makes the access to different databases transparent to the user. We use virtual tables defined and configured by grid site administrators to "virtually" represent the physical tables located at different grid sites. Each grid site can maintain its own view of the data, but there is one virtual table that connects all physical tables. This scheme can bring some advantages: it allows the definition of user permissions and access policies for each grid site; it allows data to be kept confidential; it offers to the grid user one single view of the data; it hides from the grid user the physical organization and location of data tables what can reinforce data security and confidentiality; integrate heterogeneous databases; it can be utilized to store larger tables, since physical tables are distributed.