Don't Scrap It, Wrap It! A Wrapper Architecture for Legacy Data Sources

Abstract

Garlic is a middleware system that provides an integrated view of a variety of legacy data sources, without changing how or where data is stored. In this paper, we describe our architecture for wrappers, key components of Garlic that encapsulate data sources and mediate between them and the middleware. Garlic wrappers model legacy data as objects, participate in query planning, and provide standard interfaces for method invocation and query execution. To date, we have built wrappers for 10 data sources. Our experience shows that Garlic wrappers can be written quickly and that our architecture is flexible enough to accommodate data sources with a variety of data models and a broad range of traditional and non-traditional query processing capabilities.