Data update in a land information network [thesis]

Robin C. Mullin
1988
This research deals with the problem of the on-going update of data exchanged in a land information network. In the past, major developments have been undertaken to enable the exchange of data between land information systems. Once a copy of a data set has been exchanged two questions must be faced: What happens to a copy of land information, collected and maintained by another agency, once it updates its information? How are data updates propagated in a land information network? A model of a
more » ... nd information network and the data update process have been developed. Based on these, a functional description of the database and software to perform data updating is presented. A prototype of the data update process was implemented using the ARC/INFO geographic information system. This was used to test four approaches to data updating. The four approaches are: bulk, block, incremental, and alert updates. A bulk update is performed by transferring a complete copy of an updated file and replacing the superseded file with the updated one. A block update requires that the data set be partitioned into blocks. When an update occurs, only the blocks which are affected need to be transferred. An incremental update approach records each feature which is added or deleted and transmits only the features needed to update the copy of the file. An alert is a marker indicating that an update has occurred. It can be placed in a file to warn a user that if he is active in an area containing markers, updated data is available.
doi:10.26190/unsworks/8133 fatcat:vllvwnk5obcndab6r3cayellvi