Towards Integrating Workflow and Database Provenance

While there has been substantial work on both database and workflow provenance, the two problems have only been examined in isolation. It is widely accepted that the existing models are incompatible. Database provenance is fine-grained and captures changes to tuples in a database. In contrast, workflow provenance is represented at a coarser level and reflects the functional model of workflow systems, which is stateless-each computational step derives a new artifact. In this paper, we propose a new approach to combine database and workflow provenance. We address the mismatch between the different kinds of provenance by using a temporal model which explicitly represents the database states as updates are applied. We discuss how, under this model, reproducibility is obtained for workflows that manipulate databases, and how different queries that straddle the two provenance traces can be evaluated. We also describe a proof-of-concept implementation that integrates a workflow system and a commercial relational database.