CMDB quality depends on consistent identification, reconciliation and ownership. More records do not automatically mean a more useful configuration model.
Before you start
You should understand tables, records and the difference between client-side and server-side scripts. Work in a development instance with representative permissions. Identify execution scope, transaction timing and the current user before attributing behavior to a platform script or business rule.
The practical goal is to reason through this situation: Two sources reporting one server need rules determining identity and authoritative attributes. Read the walkthrough first, then try the interview exercise before opening its answer. The important part is explaining the decision and its consequences, rather than remembering a definition alone.
Step-by-step walkthrough
Step 1: Define identity evidence
Multiple reports of one asset need consistent identification rules.
Step 2: Assign authoritative attributes
Different sources may own different fields.
Step 3: Use supported reconciliation
Avoid uncontrolled direct inserts that bypass quality mechanisms.
Worked scenario
Two sources reporting one server need rules determining identity and authoritative attributes.
Discovery and an external inventory both report server S. Without shared identification, the CMDB contains two servers; without reconciliation, one source may overwrite a more authoritative attribute. Record source ownership and use supported identification behavior so repeated updates converge instead of increasing record count.
Common mistake
Direct uncontrolled inserts can create duplicates and contradictory facts.
Verify the behavior
Import the same asset from both sources and verify identity and authoritative values.
Interview exercise
Plan a configuration integration.
Answer and reasoning
Use supported identification and reconciliation behavior, track source ownership and verify duplicate prevention on repeated input.
Continue learning
Compare the scenario with the ServiceNow interview questions and test your understanding with the ServiceNow MCQs. For terminology and implementation details, consult the reference material.