If you need to add or modify a function or special register mapping, you can use any text editor to make changes to DialectMappings.hcomap, located in the %ALLUSERSPROFILE%\Micro Focus\Enterprise Developer\hcopg directory.
Function Customization Example
psql> create function atanh (input float) returns float
AS
$BODY$
BEGIN
return log((1 + input) / (1 - input)) / 2;
END;
$BODY$
LANGUAGE plpgsql;
psql> \set x 0.75
psql> select atanh(:x);
Insert the following right before the end tag </NameMappingDataSet> in DialectMappings.hcomap and save:
<DB2NameMapping>
<DB2Name>atanh</DB2Name>
<SQLServerName>atanh</SQLServerName>
<IsFunction>true</IsFunction>
<IsSpecialRegister>false</IsSpecialRegister>
</DB2NameMapping>