13. A process operable on one or more computers for identifying duplicate records among a plurality of records in a database, each record having a plurality of fields, comprising: (a) setting a threshold match probability; (b) selecting one or more of said fields for comparison; (c) calculating record match probabilities for each of a plurality of possible patterns, wherein each pattern is a different permutation of comparisons between said fields and wherein each record match probability is a posterior probability that two records match given that the two records fit the respective pattern; (d) identifying patterns having record match probabilities higher than said threshold match probability; (e) disregarding patterns having record match probabilities lower than said threshold match probability; (f) determining which record pairs within the plurality of records have one or more of said identified patterns; and (g) analyzing said record pairs to determine whether said records are duplicates; and (h) merging duplicate records, wherein said threshold match probability and said record match probabilities are Bayesian posterior probabilities; and wherein steps (c)-(e) occur prior to steps (f)-(h).
13. A process operable on one or more computers for identifying duplicate records among a plurality of records in a database, each record having a plurality of fields, comprising: (a) setting a threshold match probability; (b) selecting one or more of said fields for comparison; (c) calculating record match probabilities for each of a plurality of possible patterns, wherein each pattern is a different permutation of comparisons between said fields and wherein each record match probability is a posterior probability that two records match given that the two records fit the respective pattern; (d) identifying patterns having record match probabilities higher than said threshold match probability; (e) disregarding patterns having record match probabilities lower than said threshold match probability; (f) determining which record pairs within the plurality of records have one or more of said identified patterns; and (g) analyzing said record pairs to determine whether said records are duplicates; and (h) merging duplicate records, wherein said threshold match probability and said record match probabilities are Bayesian posterior probabilities; and wherein steps (c)-(e) occur prior to steps (f)-(h). 14. The process according to claim 13 , wherein said step of calculating record match probabilities comprises: calculating objective values relating to said fields; approximating subjective values relating to said fields; estimating an average number of duplicate records; estimating a total number of distinct duplicate records using said subjective values; determining a probability of a match between said records using said estimated average number of duplicate records and said estimated total number of distinct duplicate records; determining a probability of no match between said records; determining a conditional probability of a match between at least one of said fields of said records, given a match between said records, using said subjective values; and determining a conditional probability of a match between at least one of said fields of said records, given no match between said records, using both said objective values and said subjective values.