Scientific workflow systems are increasingly used to automate complex data analyses, largely due to their benefits over traditional approaches for workflow design, optimization, and provenance recording. Many workflow systems employ a simple dependency model to represent the provenance of data produced by workflow runs. Although commonly adopted, this model does not capture explicit data dependencies introduced by "provenance-aware" processes, and it can lead to inefficient storage when workflow data is complex or structured. We present a provenance model, extending the conventional approach, that supports (i) explicit data dependencies and (ii) nested data collections. Our model adopts techniques from reference-based XML versioning, adding annotations for process and data dependencies. We present strategies and reduction techniques to store immediate and transitive provenance information within our model, and examine trade-offs among update time, storage size, and query res...
Adriane Chapman, H. V. Jagadish, Prakash Ramanan