1. A system for updating records in a tableset T of a family, in relation to N source files denoted as S 1, S 2,..., S N, said N at least 1, said tableset T having M tables T 1 T 2,..., T M, said M at least 1, said N source files logically associated with said M tables, said family having a common family key K F across the M tables and across the N source files, a fileset S A comprising files S 1A, S 2A,..., S NA respectively embodying S 1, S 2,..., S N at a time t A such that T 1, T 2,..., T M at the time t A accurately reflects S A, and a fileset S B comprising files S 1B, S 2B,..., S NB respectively embodying S 1, S 2,..., S N at a time t B, said t B and t A being different times, the system comprises: a Delta program adapted to generate a dataset D UP of non-redundant family keyvalues embodying K F, each said non-redundant family keyvalue drawn from selected Update records of S iB relative to S iA, said selected Update records not having any redundant family keyvalues, for i&equals;1, 2,..., N; a Trigger program adapted, for i&equals;1, 2,..., N: to step through all records of S iB, including to compare the family keyvalue K FVR within each record of S iB against the family keyvalues in the dataset D UP and to save in a file &Dgr;S i each said record of S iB for which K FVR equals one of the family keyvalues K FV in the dataset D UP ; a Bridge program adapted to generate files &Dgr;T 1, &Dgr;T 2,..., &Dgr;T M that includes the data in &Dgr;S 1, &Dgr;S 2,..., &Dgr;S N in a form that is compatible with the M tables T 1, T 2,..., T m, respectively; and at least one Load program adapted to update the tables T 1, T 2,..., T M with the data in &Dgr;T 1, &Dgr;T 2,..., &Dgr;T M, respectively.