Merged data products are created by joining two or more data objects comprised of analyses from the same sampling device.   For example, many different investigators analyze water samples drawn from the same Niskin bottles.  The various types of data are then submitted to the Data Management Office (DMO) for inclusion in the larger database.  

  The DMO has developed a "merge" utility based on the join function from the jgofs Data Base Management System.   Data records from two data objects are combined into a temporary 'constructed object'.   Additional data objects are then merged with the constructed object until all data records have been added.   Data records must have a relationship that is evident in the data itself. All data collected by the same sampling device (Niskin bottle casts) share that relationship.   The parameter (variable) list of the newly "merged" object is the union of the variable lists of the two input objects.   Record (row) matching is attempted wherein records of the two objects match when the values for all parameters in the match set have the same value.   The resulting number of records is the number of records in the first object that have a match with some record in the second object.   In cases where more than one record have identical matched sets of values (replicates), only the first record appears in the merged object.   This is rare since replicates were discouraged.