SNOW-CSA Database Administration and CMDB Practice Question
A custom table 'u_custom_server' extends 'cmdb_ci_server' and has additional fields. The admin notices that while regular attribute updates on the parent table propagate correctly to the child, some custom fields are not being updated during discovery. What is the most likely cause?
⚠ Common exam trap
Many candidates assume discovery updates all fields on a table automatically, but ServiceNow's CMDB requires explicit configuration of identification rules to control which fields are used for matching and updating, especially for custom fields on extended tables.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The identification rule does not include custom fields.
ServiceNow's CMDB identification and reconciliation framework uses identification rules to determine which fields are used to match CI records during discovery. Custom fields on a child table like 'u_custom_server' are not automatically included in the parent table's identification rule; they must be explicitly added to the identification rule for the CI class. Without this, the discovery probe may create duplicate CIs or fail to update those custom fields, as the system does not consider them part of the unique identifier or update set.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The custom fields are not defined as 'Active' in the dictionary.
Why it's wrong here
Inactive fields would not appear in the UI but would still be updatable by backend processes.
- ✗
The discovery probe does not have access to the custom fields.
Why it's wrong here
Probes populate all defined fields on the CI; custom fields are included automatically.
- ✓
The identification rule does not include custom fields.
Why this is correct
If custom fields are not part of the identification rule, discovery will not update them.
- ✗
The custom table has a stale glide record.
Why it's wrong here
A stale glide record would cause broader issues, not just custom fields.
Go deeper
Related to this question
About these practice questions
Courseiva writes every SNOW-CSA question from scratch — 504 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This SNOW-CSA practice question is part of Courseiva's free ServiceNow certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SNOW-CSA exam.