1. A method for determining whether records are similar in a database containing both structured and unstructured, free-text data, the method comprising the steps of: accessing two of the records from the database for evaluation; and evaluating a match between the two records as a weighted match between each of a plurality of available fields, such that a matching process is selected as appropriate from among a group of matching processes including strict Boolean, ordinal, and vector-based matching processes, wherein: when a strict Boolean matching process is selected, applying a match function as an exact match test; when an ordinal matching process is selected, applying a match ffunction that makes use of information concerning the size and ordering of the data domain; and when a vector-based matching process is selected applying a match function that uses a vector space frequency test.