The 'information_schema' database stores database column name, type, etc basically the structure of the database. All users should have access to this as default.

Since you're talking cPanel, I assume you're using phpMyAdmin to access the database. In the top-left corner of phpMyAdmin, if your drop-down list only includes information_schema and not the database referenced in your (Interspire store) admin, you either do not have access for that user, or the database is hosted elsewhere, doubtful, but still possible.

If you have cPanel access, go to MySQL Databases (below Databases header). It is entirely possible your database and cPanel usernames are different and so, have different access levels. Check the the users/databases under Current Databases to see who has access to your ISC database, click the Username to edit the Privileges. ISC requires ALL. You may neeed to add your cPanel username to the ISC database, or simply log-in to phpMyAdmin using the appropriate username/password which you will find in your ISC config.php file.

And last night, I ran a 6000-line SQL script on the database to import all the custom data fields from Actinic :D