This section describes functions for handling mapping tables. A mapping table can be used to replace field values or field names during script execution.
Mapping functions can only be used in the load script.
The ApplyMap script function is used for mapping the output of an expression to a previously loaded mapping table.
ApplyMap('mapname', expr [ , defaultexpr ] )
The MapSubstring script function is used to map parts of any expression to a previously loaded mapping table. The mapping is case sensitive and non-iterative, and substrings are mapped from left to right.