DOCUMENTATION NOTES FOR

IBM Informix ESQL/C Programmer's Manual

Date: 03/2003

Version: 9.53


I. Overview

This document describes feature and performance topics not covered in the IBM Informix ESQL/C Programmer's Manual or modified since publication.


II. Using GLU (GLS for Unicode) Interface Functions

The use of GLU is turned off, by default and 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 the existing and new applications.  Every existing application 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.

Using the -glu compiler flag

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 ...

Using the GL_USEGLU environment variable

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 ...

III. Enhanced Functionality of the DESCRIBE Statement

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>
 

IV. New Environment Variables

      a.  IFX_PAD_VARCHAR   when the environment variable set to 1, the client sends varchar datatype with padded trailing spaces. When this environment is not set(default)the client sends varchar datatype value without trailing.  This environment IFX_PAD_VARCHAR  needs to set only at the client side and it is supported only with IBM Informix ESQL/C Version 9.53 or above and IBM Informix Dynamic Server Version 9.40 or above.

      b.  BIG_FET_BUF_SIZE   This is an enhancement of FET_BUF_SIZE  to support cursor buffers greater than 32,769 but less than or equal to 4MB. This environment is supported only for XPS servers starting from Version 8.40.UC1.

      c.  BLANK_STRINGS_NOT_NULL  when this environment is set to 1 the string host variable stores an empty string as a single blank followed by a null terminator, without environment setting, string host variable stores an empty string as null.  This environment BLANK_STRINGS_NOT_NULL  is mainly provided to support backward compatibility for 7x against  string host variables and  needs to be set only at client side.

 

 


© Copyright International Business Machines Corporation 2003. All rights reserved.
US Government User Restricted Rights—Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp.