To make a direct connection to an Informix database, you must install the Informix Client SDK or IConnect on the client machine and set up an ODBC driver.
How to set up clients
Install the Informix Client SDK or the IConnect application on each remote client machine you want to connect directly to your database.
This makes the Informix client setup files you need available to you. Consult your Informix documentation for further information or help on how to install these applications.
If the Informix server is running on the same host as the client application, you can skip this step.
Be sure that the user on each client machine you want to connect directly to your database has the Connect permission on the database server.
Set up an ODBC driver connection.
For WindowsUse SetNet32 to configure the client so that it can work with the available objects. Also use SetNet32 to add a new Informix server.
For UNIXSet up the $INFORMIXDIR and add the appropriate database server entry in the sqlhosts file in the $INFORMIXDIR\etc directory.
Consult your Informix documentation for further information or details on how to set the ODBC driver connection.
Test the connection by adding a spatial database connection from ArcCatalog. Instructions for this can be found in the topic Creating spatial database connections in the "Data management with ArcCatalog" section of the help.
Tip
If you are using ArcSDE 8.3 or lower, set the SDEHOME environment variable to point to the directory where the client application's dynamically linked library (.DLL) files are stored.