The feature of DB2 access in IBM Informix ESQL/C has been removed since IBM Informix ESQL/C Version 3.70.xC2.
To support DB2, IBM Informix introduced the feature of DB2 access in IBM Informix ESQL/C version 2.90. This feature allows the Informix users to access their DB2 database server from their Informix ESQL/C programs that are compiled by Informix esql command with option '-db2'.
Since IBM introduced the common IBM Data Server Drivers for both DB2 and Informix several years ago, this feature has not been maintained and updated on the new capabilities, feature set and enhancements for the DB2 server. All the old DB2 versions certified with this features are already out of support. It would be risky for users to use this feature with the current supported versions of DB2. Considering that the Informix ESQL/C driver is fundamentally designed for the Informix server, it was decided to remove this feature from Informix ESQL/C. The esql command option '-db2' was already removed from Informix ESQL/C version 3.70.xC2. The binaries of this feature will also be removed from Informix ESQL/C version 3.50.xC9 and 3.70.xC3
List of binaries being removed from CSDK (xC3)
For Unix platform:
For those who need to access DB2, IBM highly recommends the use of IBM Data Server Drivers that are actively maintained and updated by IBM