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

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 %INFORMIXDIR%\bin directory.

C: cd %INFORMIXDIR%\bin
C: find “INFORMIX-SQL” isqlt09a.dll

The output of the find command is shown:

- - - - - - - - - ISQLT09A.DLL
INFORMIX-SQL Version 9.20T1N79