Modelling outsourceable transactions on polygon-based cadastral parcels

Modern land administration systems must fulfil the emerging need for a faster and more efficient processing of real estate transactions. In order to achieve such a goal, one way to go can be to outsource a larger segment of the cadastral geometry updating process to the actors external to the organisation maintaining the data. In case the spatial component of the combined legal–spatial transactions is to be outsourced, the underlying transaction processing system must be able to autonomously handle all possible cases in a safe and consistent manner. In this paper we developed a framework that can be used to design a system that is based on standard database transaction concepts and guarantees the safe processing of externally prepared transactions on polygon-based cadastral parcels. In order to be able to detach the process of editing from the consistency control, we adjusted our basic concepts to only consider the net effect of a transaction. In creating the framework we first detect all possible types of transactions. We do that by observing the cardinalities of the transaction’s affected and the resulting sets of parcels and the identities of each set’s members. Following the detection, we attach the basic integrity constraints to each of the transaction types. Finally we classify the detected transaction types into two subtypes with the primary criteria being the strict or relaxed requirements regarding the planar partition correctness. A strict definition of what can be done within each such transaction type provides a reference that can be used for linking the legal and the spatial component of a combined legal–spatial transaction. In order to substantiate the developed framework, we describe the implementation of a proof of the concept system.