Dans cette thèse, nous proposons un cadre générique d'optimisation de requêtes dans les environnements hétérogènes répartis. Nous proposons un modèle générique de description de sources (GSD), qui permet de décrire tous les types d'informations liées au traitement et à l'optimisation de requêtes. Avec ce modèle, nous pouvons en particulier obtenir les informations de coût afin de calculer le coût des différents plans d'exécution. Notre cadre générique d'optimisation fournit les fonctions unitaires permettant de mettre en œuvre les procédures d'optimisation en appliquant différentes stratégies de recherche. Nos résultats expérimentaux mettent en évidence la précision du calcul de coût avec le modèle GSD et la flexibilité de notre cadre générique d'optimisation lors du changement de stratégie de recherche. Notre cadre générique d'optimisation a été mis en œuvre et intégré dans un produit d'intégration de données (DVS) commercialisé par l'entreprise Xcalia - Progress Software Corporation. Pour des requêtes contenant beaucoup de jointures inter-site et interrogeant des sources de grand volume, le temps de calcul du plan optimal est de l'ordre de 2 secondes et le temps d'exécution du plan optimal est réduit de 28 fois par rapport au plan initial non optimisé. / This thesis proposes a generic framework for query optimization in heterogeneous and distributed environments. We propose a generic source description model (GSD), which allows describing any type of information related to query processing and optimization. With GSD, we can use cost information to calculate the costs of execution plans. Our generic framework for query optimization provides a set of unitary functions used to perform optimization by applying different search strategies. Our experimental results show the accuracy of cost calculus when using GSD, and the flexibility of our generic framework when changing search strategies. Our proposed approach has been implemented and integrated in a data integration product (DVS) licensed by Xcalia – Progress Software Corporation. For queries with many inter-site joins accessing large size data sources, the time used for finding the optimal plan is in the order of 2 seconds, and the execution time of the optimized plan is reduced by 28 times, as compared with the execution time of the non optimized original plan.

Abstract The "System of Mediation", which plays an important role in autonomy is a judiciary alternative for the purpose of seeking a practical and prompt solution to disputes among people. In conformity with sensible and fair practices, its function can be marked by providing multiple choice of feasible arrangement over emotionally unpleasant behavior and misdeeds so that advice will be put into use and favorable negotiation can be reached by those who are involved. To have the best of both worlds will give free reign to the nature of mediation. In this monographic study, there are separate descriptions of arbitrated occurrences concerning districts of county and town along with comparative research about arbitral structure between domestic organization and foreign countries. Related complementary assignments are also mentioned in this paper, such as the qualification, ways of election and procedure of appointment of arbitral committee in autonomous districts. Improvement is also taken into consideration with a view to the optimizing of the arbitral system. Findings of study: (1) Superfluous arbitral staff results in unsuccessful mediation. (2) Dubiety exists in the failed arbitral certificates. (3) The identity, rights and obligations of committee members aren't guaranteed specirically. Suggestions: (1) Professional expertise and deliberation should be the critical requirements for the election of mediatory committee and secretary. (2) Appropriate reward or extra compensation should be paid to the arbitral committee as they are qualified public officials. (3) Skilled mediator should be exclusively responsible for the task of mediation. (4) Advance in juristic knowledge and training for the arbitral committee and reliable secretary involved are required to bring about a available agreement. (5) Reform in the operation of arbitral organization may promise better service for the public.