This paper presents a strategy for applying sampling techniques to relational databases, in the context of data quality auditing or decision support processes. Fuzzy cluster sampling is used to survey sets of records for correctness of business rules. Relational algebra estimators are presented as a data quality-auditing tool.

Relational representation of knowledge makes it possible to perform all the computations and decision making in a uniform relational way [46], by means of special relational compositions called triangle and square products. These were first introduced by Bandler and Kohout in 1977 [11],[5],[2] and are referred to as the BK-products in the literature [22],[17],[18]. Their theory and applications...