Master Index Match Engine Reference

Condensed AlphaNumeric SSN Comparator (nS)

The Condensed AlphaNumeric SSN Comparator is designed specifically for matching on numeric strings and is very useful for matching social security numbers or other unique identifiers. This comparison function can compare either alphanumeric values or numeric values, and takes into account such uncertainty factors as string length, transpositions, key punch errors, and visual memory errors. It can also take into consideration field length, allowed character types, and invalid values. It accepts the parameters listed in Table 9.

Table 9 nS Comparison Function Parameters


Parameter	Description
fixed-length	An optional parameter that takes the length of the field value into account. If a fixed length is specified, the match engine considers any field of a different length to be a non-match. Specify any integer smaller than the value specified for the size specified for the field (for more information, see Matching Rules Section).
character-type	An indicator of whether the field must be all numeric. Specify “nu” for numeric only, or specify “an” to allow alphanumeric characters. The match engine considers any fields containing characters that are not allowed to be a non-match.
invalid-characters	A list of invalid characters for the field. If you specify a character, the match engine considers fields that consist of only that character to be a non-match. For example, if you specify “0”, then an SSN field cannot contain all zeros. Specify as many alphanumeric characters as needed, separated by a space.