Date: 06/2003
Version: 9.53
This document describes feature and performance topics not covered in the IBM Informix ESQL/C Programmer's Manual or modified since publication.
By default, the use of GLU is turned off. GLS will use the locale files for Unicode and GB18030-2000. The primary reason for this is that C++ linker is required in order to use ICU. This will have a wide impact on both existing and new applications. Existing applications will have to be re-linked using C++ and all new applications will require a C++ linker. Turning GLU off by default mitigates this condition.
There are two methods to use the GLU functions in and ESQL/C application.
When compiling an ESQL/C application, you can use the -glu flag to invoke the GLU functions as in the following example:
esql -o try -glu try.ec ...
You can also invoke the GLU functions by setting the GL_USEGLU environment variable to 1. You can then compile ESQL/C programs without specifying the -glu flag.
setenv GL_USEGLU 1 esql -o try.ec ...
IBM Informix Dynamic Server, Version 9.40 provides enhanced functionality of the DESCRIBE statement. This allows you to use the WHERE clause as an input parameter in INSERT and UPDATE statements. The following new syntaxes are supported:
EXEC SQL DESCRIBE [OUTPUT] <statement-name descriptor> EXEC SQL DESCRIBE INPUT <statement-name descriptor>
Beginning with ESQL/C 9.53.UC2, ESQL/C will support the Pluggable Authentication Module (PAM) method for client-server authentication. Users who use this feature will need to re-write their client applications and would need to have a callback function registered in their application to support the challenge-response mechanism that this feature supports.
An example of the use of the callback function is available as a demo shipped with ESQL/C by the name of pamdemo.ec