For many years ago, the term repository has been used in a restricted manner, since it only addressed metadata management in the context of database management systems. Nowadays it is used in a much broader sense and covers multiple services supporting design applications. Our concern is to make well customized repositories available for users. To reach this goal, we present this paper which has a main objective of improving the performance of shared database pattern in the Repository Model. Accordingly, the presented work aims to increase the level of performance of the shared repository pattern when large amounts of data are to be shared by reducing the number of times that is required to access the central database and also to save the cost rather than increasing the speed of response for the subsystems requests to access their desired data. Accordingly, the idea of improvement was based on the establishment of buffer where repository model is an organization model used as a storage medium of a huge database. Also, it is used in interactions between the subsystems of the system in architectural design showing the exchange of data between the subsystems in the system as a whole. The proposed model to achieve the required enhancement was simulated, and the output simulated results show its capability of reducing the access time of data, increasing the speed of accessing the data, increasing the system performance, and also increasing the efficiency of the system work. Also, the proposed model was compared with the approach of shared repository pattern and the results showed that the proposed approach outperforms better through making enhancement in reducing the access time and increasing the speed of accessiing the data.

Key words: Database repository model, buffer, subsystem, RDBMS, central database, shared database.