The following are the key features and modules available to manage tables and columns in the ServiceNow platform:

• System Definition | Tables & Columns: This module lists all the tables that exist in the ServiceNow instance in a single page. It offers a quick way to see a list of all the columns in a table, along with the attributes of each column, as shown in the following screenshot:

• Schema map: The schema map feature can be used to display relationships between tables visually, thereby helping you to understand the relation between tables and navigate through the database structure. As shown in the following screenshot, the schema map captures the following different intertable relationships:
• • Many-to-many relationships
  • Tables that extend other tables
  • Tables that reference other tables through reference fields

• Tables: The System Definition | Tables modules can be used to quickly find information about a table, such as its system name and the table that it is extending (extended table).
• Dictionary: The System Definition | Dictionary module lists information that defines the entire database schema. Dictionary is also referred to as the data dictionary.