Design and Implementation of an Efficient, Reliable and Safe Work-Package Database System at CERN

<!--HTML-->The Activity Coordination Tool (ACT) is a web application designed to automate theplanning and coordination of work packages. In the CMS experiment at CERN it isimportant that work packages in the underground facilities are properly planned in order to not jeopardize time schedules, equipments, budgets and safety. The subject of this thesis is the development of the database schema used by the ACT application. The schema has been developed from scratch in order to best fit the needs of CMS andto cover all aspects of the planning and coordination process not found in other CERN databases.<br><br>Models and diagrams of the database schema are based on a step by step description of the work package process. This step by step description was used to organize the data, to make the data and data relationships consistency, and to make the database structure flexible for extensions in the future. These models would eventually be used to implement the schema in the CMS online database.<br><br>Another database at CERN has many similarities with the ACT database. These two databases will eventually merge due to common interest, and the ACT database schemaneeded therefore to resemble some tables in this database in order to facilitate the merging. Some problems with network traversal and security needs to be solved before these two databases can be merged.<br><br> The architecture and usage of the database schema can affect the database performance but it doesn t contribute to the reliability of the databases system. The hardware and software components making up the database system itself are usually the main contributors to this. The CMS online network work hard to keep the performance and reliability of their database system as good as possible. Everything from disks to network connections is redundant. In addition to component redundancy are features provided by Oracle used to improve performance. The amount of server redundancy does however seem a bit exaggerated, and the performance could be slightly improved if other Oracle features were used.