Table schema maps are a very useful tool to aid in visualizing the setup of a table and its relationships to other tables and fields in ServiceNow. This functionality is something that every ServiceNow implementor or admin should be familiar with. Schema maps are documented here in the ServiceNow wiki.While the schema map is useful, it can also be difficult to navigate to unless you know exactly where to look. The only place in the system to access the schema map is from the 'Tables and Columns' module and this is only available to users with the admin role. In this post I'll show you how you can make the schema map for a given table more accessible by creating a global UI action link that allows you to display the table schema map from any form in the system - for any role you want.

http://www.servicenowguru.com/system-ui/ui-actions-system-ui/schema-map-any-form/