Compatibility of preexisting ESQL/C applications with current library versions

You specify the esql command-line options (in The esql command-line options for HCL OneDB general libraries) to tell the esql command which version of the HCL OneDB™ libraries to link with the application. After the esql command successfully compiles and links your application, the version of the HCL OneDB general libraries is fixed. When you install a new version of , you receive new copies of the HCL OneDB general libraries. Whether you need to recompile and relink your existing applications to run with these new copies depends on the factors that the following table describes.
Change to the HCL OneDB general library Version of the HCL OneDB general library Need to recompile or relink?
New release of the HCL OneDB general libraries Static

Thread-safe static

Only if the application needs to take advantage of a new feature in the new release
HCL OneDB general libraries in new release have a new major-version number Shared

Thread-safe shared

Only if the application needs to take advantage of a new feature in the new release
HCL OneDB general libraries in new release have a new API-version number Shared

Thread-safe shared

Must recompile and relink

On UNIX™, you can use the ifx_getversion utility to determine the version of the HCL OneDB library that is installed on your system.

In Windows™ environments, use the following find command to find the occurrence of the string that contains the version number in the isqlt09A.dll. The command needs to be issued from the %ONEDB_HOME%\bin directory.
C: cd %ONEDB_HOME%\bin
C: find “INFORMIX-SQL” isqlt09a.dll
The output of the find command is shown:
- - - - - - - - - ISQLT09A.DLL
INFORMIX-SQL Version 9.20T1N79