Use DB–Access to execute the xpg4_is.sql file in the $INFORMIXDIR/etc directory. This SQL file creates the Information Schema and installs the views for a specified database. The following command creates the Information Schema for database mystores:
dbaccess mystores $INFORMIXDIR/etc/xpg4_is.sql
The Information Schema adds to the database four information-only views that conform to X/Open XPG4 with Informix extensions. After you run xpg4_is.sql, use DB–Access to retrieve information about the tables and columns that you have access to in the specified database. For more information on Information Schema views, see the IBM Informix: Guide to SQL Reference.