CMDB
The CMDB (Configuration Management Database) is the set of related tables that record the CIs in your environment and the relationships between them, acting as the single source of truth for service context.
Also searched as: configuration management database, ServiceNow CMDB.
In practice
It is not one table: cmdb_ci is the base class, extended classes hold class-specific attributes, and cmdb_rel_ci stores relationships. Populated by Discovery, integrations and Service Mapping, it is only as useful as its completeness and correctness — which is why CMDB health dashboards exist.
Example
Impact analysis on a change to a database CI walks cmdb_rel_ci upward to show the two business applications and the customer-facing service that would be affected.
What interviewers check
Interviewers separate people who describe a table from people who describe a governed data model with owners, health metrics and reconciliation.
Practise this topic
Related CMDB terms
- Configuration Item (CI)A Configuration Item is any component you need to manage in order to deliver an IT service — a server, an application, a laptop, a service — stored on cmdb_ci or one of its extended class tables.
- DiscoveryDiscovery is ServiceNow's agentless process that scans networks through a MID Server, identifies devices and applications, and creates or updates the matching CIs in the CMDB.
- CSDMCSDM (Common Service Data Model) is ServiceNow's prescriptive blueprint for how to model services, applications and infrastructure so every product on the platform reads the same data the same way.