1. A data base management system that provides multiple-input, multiple-output-per-input user-defined-function-based operations, the database management system comprising: at least one processor and electronic memory; a database-query processor, executed on a computer processor controlled by computer instructions stored in a computer-readable memory, that makes multiple calls to a multiple-input, multiple-output-per-input user-defined-function, in each call transmitting a next input to the multiple-input, multiple-output-per-input user-defined-function; and the multiple-input, multiple-output-per-input user-defined-function, executed on a computer processor controlled by computer instructions stored in a computer-readable memory, that uses three different memory buffers, the contents of which are maintained for three different time periods, to compute and return to the database-query processor multiple outputs in response to at least one of the multiple inputs.