1. A computer implemented method for constructing a referentially-complete target subset database from a source database, the method comprising: estimating an expected size of the target subset database based at least in part on application of one or more subset rules on the source database; receiving at least one modified subset rule, the modified subset rule based at least in part on the expected size of the target subset database; creating a subsetting execution plan by applying the at least one modified subset rule to the source database; and generating, by a computer, the referentially-complete target subset database by applying the selected subset execution model to the subsetting execution plan.