Match field comparison functions, or comparators, compare the values of a field in two records to determine whether the fields match or how closely they match. The fields are then assigned a matching weight based on the results of the comparison function. You can use several different types of comparison functions in the match configuration file in order to customize how the Master Index Match Engine matches records. The comparators themselves are highly configurable and can be configured to assign differing weights or handle null values. Several comparators accept parameters that further fine-tune the matching process.
The Master Index Match Engine provides a comprehensive group of match comparison functions to enable matching on a wide variety of data. While you should be able to configure any of the default comparison functions to accurately match your data, you can create new comparison functions and integrate them into a master index application. For more information, see Creating Custom Comparators for the Master Index Match Engine.
The following topics describe each of the default comparison functions:
Certain comparison function types are very specific to the type of data being matched, such as the numeric functions and the date functions. Others, such as the Bigram and uncertainty functions, are more general and can be applied to various data fields.
Be sure to review Table 1 for information about how the parameters in the match configuration file affect the outcome of the comparator functions. For example, parameters define how null fields are handled and what the actual agreement and disagreement weights are.
The names of the comparators are configurable. The default names are used here.