Towards OLAP Query Reformulation in Peer-to-Peer Data Warehousing

Inter-business collaborative contexts prefigure a distributed scenario where companies organize and coordinate them- selves to develop common and shared opportunities. Tra- ditional business intelligence systems do not provide sup- port to this end. Peer Data Management Systems (PDMSs) have been proposed as architectures to support sharing of operational data across networks of peers while guaranteeing peers’ autonomy, based on semantic mappings that mediate between the heterogeneous schemata exposed by peers. In line with the PDMS infrastructure, in this paper we envi- sion a peer-to-peer data warehousing architecture based on a network of heterogeneous peers, each exposing query an- swering functionalities aimed at sharing business informa- tion. To enhance the decision making process, an OLAP query expressed on a peer needs be properly reformulated on the other peers. In this direction, we present a language for the definition of mappings between the multidimensional schemata of peers, and we introduce a query reformulation framework that relies on the translation of these mappings towards relational schemata. Finally, we sketch the query reformulation algorithm by outlining the reformulation steps of typical OLAP queries.