IBM Informix Dynamic Server
- The  INFORMIXDIR environment variable must define the IBM®             Informix® software installation path.
 
- The PATH environment variable must define the access path to database
client programs.
 
- On UNIX™, LD_LIBRARY_PATH
(or equivalent) must hold the             path to 
$INFORMIXDIR/lib:$INFORMIXDIR/lib/esql. 
- The IBM             Informix client libraries 
              
'INFORMIXDIR/lib/*' must be available. 
- The INFORMIXSERVER environment variable can be used to define
the name of the database             server.
 
- The sqlhost file must define the database server identified by
INFORMIXSERVER.
 
- Make sure the database client locale is properly
defined.
 
- You can make a connection test with the IBM Informix dbaccess command line tool.