SOUNDEX phonetic coding
The SOUNDEX action is used to compute a SOUNDEX code of a dictionary field and move the results to another dictionary field.
SOUNDEX codes are phonetic keys that are useful for blocking records in a matching operation.
SOUNDEX is an excellent blocking variable because it is not very discriminating and yet is used to partition the files into a reasonable number of subsets. The action is specifically designed for the English language but perhaps can be useful for languages.
The SOUNDEX action has the following format:
SOUNDEX source-field target-field
For example, the following action computes the SOUNDEX of the StreetName dictionary field and places the result in the field: StreetNameSOUNDEX field:
SOUNDEX {StreetName} {StreetNameSOUNDEX}
The RSOUNDEX (reverse SOUNDEX) action is the same as the SOUNDEX action except that the phonetic code is generated from the last non-blank character of the field and proceeds to the first. This is useful for blocking fields where the beginning characters are in error. An example of the pattern syntax is as follows:
RSOUNDEX {StreetName} {StreetNameRVSNDX}
The SOUNDEX and RSOUNDEX actions are used in the POST action section, so they are executed after pattern matching is complete for the record.
POST actions must occur before any pattern-action sets and are preceded by the line \POST_START and followed by the line \POST_END.