## 5 The Information System of the Pompeii Sustainable Preservation Project  
The purpose of the Pompeii Sustainable Preservation Project's information system is to collect and manage in an integrated manner all the data produced during the project, to facilitate both the processes of analysis and production of information and the sharing of acquired knowledge. Since the spatial attribute constitutes, as has been said, both the common denominator capable of bringing heterogeneous data back to a common factor and the main analysis tool, its correct management plays a central role in the information system which is created. At the moment, the system consists of two fundamental components: a database capable of managing different types of data together with the relative spatial attributes and a GIS platform for the presentation and analysis of the data. Both components of the information system were designed and implemented by the writer using open-source software [17]. For the realisation of the database, we used PostgreSQL, an open-source Object Oriented Relational Database Management System [18] which not only represents an extremely reliable and mature product but also allows, through the PostGIS extension, complete management of the spatial data [19]. The perfect and easy integration of PostgreSQL with QGis [20], a desktop GIS software, also open source and now established on the international scene as a valid alternative to commercial solutions, has led to its adoption inside the project. The entire database currently resides on a server at the ISPC-CNR branch in Catania (ex IBAM-CNR) and is accessible remotely through appropriate forms of data entry and/or consultation directly through QGIS. In designing and implementing an information system to manage data produced in the context of research activities conducted within the Pompeii archaeological site, it was impossible to ignore the fact that one of the aims of the Knowledge Plan of the Great Pompeii Project was the creation of an information system that, through the close combination of old and new data, considered in their exact spatial context, could generate the knowledge that is necessary to implement the planned prevention program that was the ultimate goal of the entire project [21]. Indeed, it is easy to understand how, from this perspective, the creation of a tool capable of preserving and managing both archival data and those produced by the new research conducted as part of the GPP, represented a priority requirement. Meanwhile, at the same time, the integration of the information system of the GPP with SIGECWeb [22], the General catalogue information system developed by the Italian Central Institute for Catalogue and Documentation (ICCD), with other databases and web platforms, such as the Information System for the Vesuvian Area (SIAV), certainly represented one of the most important aims among those included in the Knowledge Plan of GPP. The design of the Information System of GPP has required to mediate between the opposing extremes of observance of norms and standards, according to the ICCD cataloguing system [23], on the one hand, and the innovation on the other, that was necessary to find a space for recording the specific features of both the Pompeii site and the methodologies employed in the context of the GPP's activities. In this perspective, aimed in any case at the creation of an organic and coherent system for managing Pompeii's archaeological evidence, from the urban scale to the individual wall elements, it was made a recourse, in designing the Information System of the GPP, to the catalogue schemas drawn up by the ICCD [24]. The SI model (Slto archeologico/archaeological Slte) was used to archive two different levels of the ancient city, the site in its entirety and the divisions into regions.