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Records retention in relational database systems

The recent introduction of several pieces of legislation mandating minimum and maximum retention periods for corporate records has prompted the Enterprise Content Management (ECM) community to develop various records retention solutions. Records retention is a significant subfield of records management, and legal records retention requirements apply over corporate records regardless of their shape or form. Unfortunately, the scope of existing solutions has been largely limited to proper identification, classification and retention of documents, and not of data more generally.
 In this paper we address the problem of managed records retention in the context of relational database systems. The problem is significantly more challenging than it is for documents for several reasons. Foremost, there is no clear definition of what constitutes a business record in relational databases; it could be an entire table, a tuple, part of a tuple, or parts of several tuples from multiple tables. There are also no standardized mechanisms for purging, anonymizing and protecting relational records. Functional dependencies, user defined constraints, and side effects caused by triggers make it even harder to guarantee that any given record will actually be protected when it needs to be protected or expunged when the necessary conditions are met. Most importantly, relational tuples may be organized such that one piece of data may be part of various legal records and subject to several (possibly conflicting) retention policies.
 We address the above problems and present a complete solution for designing, managing, and enforcing records retention policies in relational database systems. We experimentally demonstrate that the proposed framework can guarantee compliance with a broad range of retention policies on an off-the-shelf system without incurring a significant performance overhead for policy monitoring and enforcement.