A database interface for file update

Abstract
Database systems are concerned with structured data. Unfortunately,data is still often available in an unstructured manner (e.g., infiles) even when it does have a strong internal structure (e.g.,electronic documents or programs). In a previous paper [2], wefocussed on the use of high-level query languages to access suchfiles and developed optimization techniques to do so. In thispaper, we consider how structured data stored in files can beupdated using database update languages.