Data retention laws establish rules intended to protect privacy. These define both retention durations (how long data must be kept) and purging deadlines (when the data must be destroyed in storage). To comply with the laws and to minimize liability, companies should destroy data that must be purged or is no longer needed. However, database backups generally cannot be edited to purge “expired” data and erasing the entire backup is impractical. To maintain compliance, data curators need a mechanism to support targeted destruction of data in backups.
In this paper, we present a cryptographic erasure framework that can purge data from all database backups. Our approach can be transparently integrated into existing database backup processes. We demonstrate how different purge policies can be defined through views and enforced by triggers without violating database constraints.
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This content will become publicly available on July 12, 2025
The Intersection of Compliance, Databases, and IT Operations
Most organizations rely on relational database(s) for their day-to-day business functions. Data management policies fall under the umbrella of IT Operations, dictated by a combination of internal organizational policies and government regulations. Many privacy laws (such as Europe’s General Data Protection Regulation and California’s Consumer Privacy Act) establish policy requirements for organizations, requiring the preservation or purging of certain customer data across their systems. Organization disaster recovery policies also mandate backup policies to prevent data loss. Thus, the data in these databases are subject to a range of policies, including data retention and data purging rules, which may come into conflict with the need for regular backups.
In this paper, we discuss the trade-offs between different compliance mechanisms to maintain IT Operational policies. We consider the practical availability of data in an active relational database and in a backup, including: 1) supporting data privacy rules with respect to preserving or purging customer data, and 2) the application performance impact caused by the database policy implementation. We first discuss the state of data privacy compliance in database systems. We then look at enforcement of common IT operational policies with regard to database backups. We consider different implementations used to enforce privacy rule compliance combined with a detailed discussion for how these approaches impact the performance of a database at different phases. We demonstrate that naive compliance implementations will incur a prohibitively high cost and impose onerous restrictions on backup and restore process, but will not affect daily user query transaction cost. However, we also show that other solutions can achieve a far lower backup and restore costs at a price of a small (<5%) overhead to non-SELECT queries.
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- Award ID(s):
- 2016548
- PAR ID:
- 10528644
- Publisher / Repository:
- The 36th International Conference on Scientific and Statistical Database Management (SSDBM)
- Date Published:
- Subject(s) / Keyword(s):
- Relational Database Compliance Operational Procedures Backup and Recovery
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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